Статті в журналах: "Thermal hydraulic drive"

1

Ketelsen, Søren, Sebastian Michel, Torben O. Andersen, Morten Kjeld Ebbesen, Jürgen Weber, and Lasse Schmidt. "Thermo-Hydraulic Modelling and Experimental Validation of an Electro-Hydraulic Compact Drive." Energies 14, no. 9 (April 22, 2021): 2375. http://dx.doi.org/10.3390/en14092375.

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Electro-hydraulic compact drives (ECDs) are an emerging technology for linear actuation in a wide range of applications. Especially within the low power range of 5–10 kW, the plug-and-play capability, good energy efficiency and small space requirements of ECDs render this technology a promising alternative to replace conventional valve-controlled linear drive solutions. In this power range, ECDs generally rely on passive cooling to keep oil and system temperatures within the tolerated range. When expanding the application range to larger power classes, passive cooling may not be sufficient. Research investigating the thermal behaviour of ECDs is limited but indeed required for a successful expansion of the application range. In order to obtain valuable insights into the thermal behaviour of ECDs, thermo-hydraulic simulation is an important tool. This may enable system design engineers to simulate thermal behaviour and thus develop proper thermal designs during the early design phase, especially if such models contain few parameters that can be determined with limited information available. Our paper presents a lumped thermo-hydraulic model derived from the conservation of mass and energy. The derived model was experimentally validated based on experimental data from an ECD prototype. Results show good accuracy between measured and simulated temperatures. Even a simple thermal model containing only a few thermal resistances may be sufficient to predict steady-state and transient temperatures with reasonable accuracy. The presented model may be used for further investigations into the thermal behaviour of ECDs and thus toward proper thermal designs required to expand the application range.

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2

Konev, V. V. "Evaluation of the trailbuilder hydraulic drive thermal preparation." IOP Conference Series: Materials Science and Engineering 1103, no. 1 (March 1, 2021): 012015. http://dx.doi.org/10.1088/1757-899x/1103/1/012015.

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3

Kulikov, Ilya, Kirill Karpukhin, and Rinat Kurmaev. "X-in-the-Loop Testing of a Thermal Management System Intended for an Electric Vehicle with In-Wheel Motors." Energies 13, no. 23 (December 6, 2020): 6452. http://dx.doi.org/10.3390/en13236452.

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The article describes an elaboration of the X-in-the-loop (XiL) testing environment for a thermal management system (TMS) intended for the traction electric drive of an electric vehicle, which has each of its wheels driven by an in-wheel motor. The TMS features the individual thermal regulation of each electric drive using a hydraulic layout with parallel pipelines and electrohydraulic pumps embedded into them. The XiL system is intended as a tool for studying and developing the TMS design and controls. It consists of the virtual part and the physical part. The former simulates the vehicle operating in a driving cycle with the heat power dissipated by the electric drive components, which entails the change in their temperature regimes. The physical part includes the TMS itself consisting of a radiator, pipelines, and pumps. The physical part also features devices intended for simulation of the electric drive components in terms of their thermal and hydraulic behaviors, as well as devices that simulate airflow induced by the vehicle motion. Bilateral, real-time interactions are established between the two said parts combining them into a cohesive system, which models the studied electric vehicle and its components. The article gives a description of a laboratory setup, which implements the XiL environment including the mathematical models, hardware devices, as well as the control loops that establish the interaction of those components. An example of using this system in a driving cycle test shows the interaction between its parts and operation of the TMS in conditions simulated in both virtual and physical domains. The results constitute calculated and measured quantities including vehicle speed, operating parameters of the electric drives, coolant and air flow rates, and temperatures of the system components.

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Latynin, Andrej, Andrej SHvyryov, Irina Kondratenko, and Irina Andrejshcheva. "FEATURES OF THERMAL DIAGNOSIS METHOD FOR HYDROSTATIC TRANSMISSION OF FOREST MACHINES." Voronezh Scientific-Technical Bulletin 2, no. 2 (January 25, 2022): 42–49. http://dx.doi.org/10.34220/2311-8873-2022-42-49.

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The extraction of timber in the territory of the Russian Federation is carried out mainly by logging technical complexes, made on the basis of machines with a hydraulic drive. In turn, of the currently known types of hydrodynamic transmission, the most advanced is the hydro-static transmission. Despite the exceptional reliability of such equipment, hydrodynamic transmission, including hydrostatic transmis-sion, has a large number of failures. The main hydrostatic transmission failures include mal-functions of the wheel drive hydraulic motor. Therefore, the purpose of this study is to use the method of thermal diagnostics to reduce the number of failures in hydrodynamic transmission, including hydrostatic transmis-sion.

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5

Suslov, N. M., S. Ya Davydov, D. N. Suslov, S. A. Chernukhin, and V. S. Velikanov. "Thermal calculation of the hydraulic drive of the dragline walking mechanism." NOVYE OGNEUPORY (NEW REFRACTORIES), no. 12 (January 23, 2020): 10–12. http://dx.doi.org/10.17073/1683-4518-2019-12-10-12.

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A new device for moving walking machines is proposed. It allows you to reduce energy consumption for the movement of the dragline by eliminating the friction of the support base on the ground while maintaining the step size and providing a given direction of its movement. The thermotechnical calculation for the hydraulic dragline walking mechanism is presented with the aim of using the heat generated during the dragline movement to heat the driver’s cab during overburden operations at low ambient temperatures. Ill. 1, Ref. 10. Tab. 1.

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6

Suslov, N. M., S. Ya Davydov, D. N. Suslov, S. A. Chernukhin, and V. S. Velikanov. "Thermal Calculation of the Hydraulic Drive for a Dragline Walking Mechanism." Refractories and Industrial Ceramics 60, no. 6 (March 2020): 558–60. http://dx.doi.org/10.1007/s11148-020-00406-2.

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7

Wang, Haifei, Shimin Yang, and Tan Lu. "Mechanical transmission system of loader based on hydraulic hybrid technology." Thermal Science 25, no. 6 Part A (2021): 4233–40. http://dx.doi.org/10.2298/tsci2106233w.

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In order to solve the problems of high energy consumption, high noise and pollution gas emission existing in the mechanical transmission system of loader, a research on the mechanical transmission system of loader based on hydraulic hybrid technology is proposed. The mechanical energy and heat energy are generated by the mechanical operation of the loader, which are converted into hydraulic energy and output to the drive system. According to the fast response characteristics and high power density characteristics of the hydraulic power system relative to the thermal engine, the dynamic model of the hydraulic hybrid drive system of the loader is established. The double fuzzy PID control method is used to identify and modify the unknown load and power parameters of the drive system. Through the experiment, it is concluded that the power parameter matching of the transmission system using the hydraulic hybrid technology is more optimized, the application effect is good, and the efficiency of the power transmission system can be maximized.

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8

Ketelsen, Søren, Damiano Padovani, Torben Andersen, Morten Ebbesen, and Lasse Schmidt. "Classification and Review of Pump-Controlled Differential Cylinder Drives." Energies 12, no. 7 (April 4, 2019): 1293. http://dx.doi.org/10.3390/en12071293.

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Pump-controlled hydraulic cylinder drives may offer improved energy efficiency, compactness, and plug-and-play installation compared to conventional valve-controlled hydraulic systems and thus have the potential of replacing conventional hydraulic systems as well as electro-mechanical alternatives. Since the late 1980s, research into how to configure the hydraulic circuit of pump-controlled cylinder drives has been ongoing, especially in terms of compensating the uneven flow requirements required by a differential cylinder. Recently, research has also focused on other aspects such as replacing a vented oil tank with a small-volume pressurized accumulator including the consequences of this in terms of thermal behavior. Numerous references describe the advantages and shortcomings of pump-controlled cylinder drives compared to conventional hydraulic systems or electro-mechanical drives. This paper presents a throughout literature review starting from the earliest concepts based on variable-displacement hydraulic pumps and vented reservoirs to newer concepts based on variable-speed electric drives and sealed reservoirs. By classifying these drives into several proposed classes it is found that the architectures considered in the literature reduce to a few basic layouts. Finally, the paper compares the advantages and shortcomings of each drive class and seek to predict future research tasks related to pump-controlled cylinder drives.

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9

Jasiński, Ryszard. "Problems of the Starting and Operating of Hydraulic Components and Systems in Low Ambient Temperature (Part V)." Polish Maritime Research 24, no. 4 (December 20, 2017): 47–56. http://dx.doi.org/10.1515/pomr-2017-0135.

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Abstract A large number of hydraulic devices and systems are started in low ambient temperatures. A good example of such a device is the hoisting winch on the ship. Starting hydraulic drive units in thermal shock conditions (rapid supply of hot oil to the cold unit) may lead to incorrect operation of the actuating system, for instance, due to the loss of clearance between cooperating elements. The article presents methods to prevent the disappearance of effective clearance in a hydraulic motor started in thermal shock conditions. For this reason, the structure of the hydraulic satellite motor was complemented by elements creating special channels through which hot oil could flow and additionally heat fixed parts of the motor. This solution ensures faster heating of motor housing, thus decreasing the temperature difference between the housing and the satellites during motor start-up in thermal shock conditions.

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10

Vanin, V., and M. Kruhol. "HYDRAULIC MODELS IN THE PROBLEMS OF THERMAL POWER PLANT AUXILIARY ENERGY EFFICIENCY IMPROVEMENT." Journal of Numerical and Applied Mathematics, no. 1 (135) (2021): 36–42. http://dx.doi.org/10.17721/2706-9699.2021.1.04.

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The work is devoted to the study of thermal power plants auxiliary energy efficiency. The main mechanisms in the auxiliary systems are centrifugal mechanisms that work in complex hydraulic networks with variable productivity. The main ways to adjust the parameters of the centrifugal mechanisms are to change the speed of rotor rotation, change the guide vane angle and throttle. The operation mode of a complex hydraulic network which includes a group of centrifugal mechanisms with a mixed connection scheme is analyzed. The system of equations which characterize the hydraulic system has been obtained on the basis of Kirchhoff's laws. The centrifugal mechanisms' operating characteristics are given by approximation dependences obtained with the method of least squares and similarity laws. To analyze efficiency of different methods of centrifugal mechanisms parameters regulation, optimal control problems were set and solved. The constraints for the problems are a system of equations that describe the hydraulic system operation and technical constraints that depend on the control method. Through solving the problems, values of the optimal parameters and weighted average efficiency of the group mechanisms were obtained. Studies have shown that the most effective way to regulate the centrifugal mechanisms parameters is to use an individual frequency drive, the least effective is to use only changing angle of centrifugal mechanism's guide vane. Utilization of group control is highly efficient and not inferior to individual frequency drive. However, this statement is correct under condition of the operating characteristics agreement with the centrifugal mechanisms’ operating modes similarity.

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11

Jasiński, Ryszard. "Analysis of the Heating Process of Hydraulic Motors during Start-Up in Thermal Shock Conditions." Energies 15, no. 1 (December 22, 2021): 55. http://dx.doi.org/10.3390/en15010055.

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Conditions that prevail during harsh winters and hot summers pose a serious challenge for machine designers building devices suitable for operation in extreme weather. It is essential for the designers and the users to define the principles and conditions for the safe operation of machines and devices with hydraulic drive in low ambient temperatures. Bearing in mind the above, the author tested the hydraulic motors in thermal shock conditions (cold motors were fed with a hot working medium). This enterprise required the design and construction of a specialized stand for testing hydraulic motors, including satellite motors, in thermal shock conditions. The stand was equipped with the apparatus and a system for measuring the temperature of the moving parts of the satellite motor. The experimental tests were conducted in the laboratory of the Faculty of Mechanical Engineering and Ship Technology at Gdańsk University of Technology. The paper presents the results of tests of a correctly and incorrectly operating satellite motor during start-up in thermal shock conditions. The results concerned the course of oil temperatures, temperatures of heated elements, oil pressures, and the pressure drop in the motor. The influence of the oil pressure drop in the motor on its temperature increase was determined. The distributions of the temperature fields of the heated elements of the satellite motor during start-up in thermal shock conditions were derived by means of computer simulation. The utilization of the distribution of the temperature fields of the motor elements enables the evaluation and analysis of the work of this unit. The conducted tests may determine the conditions for the proper operation of hydraulic motors started in thermal shock conditions.

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12

Kurmaev, R. H., and A. A. Umnitsyn. "Experimental studies of the thermal management system for an electric vehicle in the X-In-The-Loop environment." Journal of Physics: Conference Series 2061, no. 1 (October 1, 2021): 012120. http://dx.doi.org/10.1088/1742-6596/2061/1/012120.

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Abstract This article presents the experience of conducting experimental studies of the thermal management system (TMS) intended for the traction electric drive of an electric vehicle, which has each of its wheels driven by an in-wheel motor, in the X-In-the-Loop environment. The paper describes the experimental bench of the thermal management system, which makes it possible to simulate the operating conditions of the high-voltage components of the traction drive of an electric vehicle from the point of view of thermal-hydraulic characteristics. A brief description of the mathematical model used in real-time calculations during both local and collaborative experimental studies is given. The process of collaborative testing of the TMS of high-voltage components of the traction drive of an electric vehicle, in the X-In-the-Loop environment, as well as the results, is demonstrated. A similar approach used in the development of TMS allows increasing the efficiency of the system developed, by optimizing the control algorithm for the executive devices of the TMS, reducing the weight, as well as the overall dimensions of the components, and conducting a detailed analysis of each component. It is also worth noting that the use of collaborative experimental research in the X-In-the-Loop environment will reduce the cost of the experiment, as well as, ultimately, the cost of the product, since with such an approach there is no need for a real test object for each company engaged in the development of one or another electric.

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13

Qiao, Guan, Geng Liu, Zhenghong Shi, Yawen Wang, Shangjun Ma, and Teik C. Lim. "A review of electromechanical actuators for More/All Electric aircraft systems." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 232, no. 22 (December 28, 2017): 4128–51. http://dx.doi.org/10.1177/0954406217749869.

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Conventional hydraulic actuators in aircraft systems are high maintenance and more vulnerable to high temperatures and pressures. This usually leads to high operating costs and low efficiency. With the rapid development of More/All Electric technology, power-by-wire actuators are being broadly employed to improve the maintainability, reliability, and manoeuvrability of future aircraft. This paper reviews the published application and development of the airborne linear electromechanical actuator. First, the general configuration, merits, and limitations of the gear-drive electromechanical actuator and the direct-drive electromechanical actuator are analysed. Second, the development state of the electromechanical actuator testing systems is elaborated in three aspects, namely the performance testing based on room temperature, testing in a thermal vacuum environment, and iron bird. Common problems and tendencies of the testing systems are summarized. Key technologies and research challenges are revealed in terms of fault-tolerant motor, high-thrust mechanical transmission, multidisciplinary modelling, thermal management, and thermal analysis. Finally, the trend for future electromechanical actuators in More/All Electric Aircraft applications is summarized, and future research on the airborne linear electromechanical actuators is discussed.

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14

Xia, Qingchao, Gul Muhammad, Bingzhe Chen, Feng Zhang, Zhifeng Zhang, Sheng Zhang, and Canjun Yang. "Investigation of Self-Driven Profiler with Buoyancy Adjusting System towards Ocean Thermal Energy." Applied Sciences 11, no. 15 (July 31, 2021): 7086. http://dx.doi.org/10.3390/app11157086.

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An underwater profiler is one of the popular platforms for ocean observation. Due to energy limitations, conventional underwater vehicles have a short life span, which cannot meet the needs of long-term ocean exploration. Therefore, there is a growing interest in using ocean energy such as ocean thermal energy and wave energy for driving. This study aimed to investigate an energy-saving and ocean thermal energy (OTE)-powered buoyancy driving system of the ocean profiler. The purpose of this study was to explore an ocean profiler buoyancy driving system powered by ocean thermal energy (OTE). According to the seawater profile temperature gradient, an OTE-powered electro-hydraulic control system was designed, and the dynamic characteristics of this system are simulated and analyzed by using the power bonding diagram method. Based on the results conducted from lake tests, this profiler possesses the self-driving capability for using OTE perfectly. This research can provide important guidance for the design of the buoyancy drive system of underwater vehicles.

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15

Udrea, Ioana, Viorel Ionut Gheorghe, Mihai Avram, Silviu Petrache, Alina Popescu-Cuta, and Romeo Traian Popa. "Solution for controlling a hydraulic motor using cloud data." E3S Web of Conferences 180 (2020): 02013. http://dx.doi.org/10.1051/e3sconf/202018002013.

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In the last period, Internet of Things (IoT) is experiencing an increasing development, and the tendency of hosting applications and especially data, in cloud computing systems is growing. Currently, most of the Building Management System (BMS) analyse directly data or transfer it to the cloud. In this context, the proposed solution aims to read indoor thermal climate data from cloud computing platform and based on them operate a hydraulic motor. The input data could be generated by an in-house sensor monitoring solution or by a foreign BMS system that transmits open source data to cloud. In this study some conditions are imposed to the input data and as a result, control current is generated and transmitted in order to command proportional electro-hydraulic valve that drive a hydraulic motor. The electro-hydraulic valve is controlled with the help of an amplifier, by a data acquisition board (DAQ) that runs LabView application. With the help of the developed software, the motor speed and the direction of rotation can be controlled. In last years, the number of requests for architectures projects with moveable elements has increased because they multiply the possible use of the buildings. With the information generated by the sensors that measure the indoor climate parameters, the hydraulic motor could be used in such a construction. Examples of atypical buildings with special functionalities that the architects would propose and that needs high torque actuation are presented in this paper.

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16

Klimov, R., and V. Kirilyuk. "EFFICIENCY OF THE NOZZLES OF CONTACT HEAT EXCHANGERS." Collection of scholarly papers of Dniprovsk State Technical University (Technical Sciences) 1, no. 38 (September 8, 2021): 92–98. http://dx.doi.org/10.31319/2519-2884.38.2021.11.

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At powerful thermal power plants or boiler houses, the efficiency depends to the greatest extent on the amount of heat lost with the cooling of turbine condensers, exhaust gases that have a high temperature. Each type of such losses is a large unused energy potential, that is, a secondary energy resource that can be used. At the same time, the use of secondary resources and industrial emissions will improve the ecological situation in the regions, and this has always been an urgent task. As a rule, large losses of thermal secondary energy resources in boilers are reduced by installing economizers and air heaters. Contact types of heat exchangers are distinguished by the best efficiency in operation. In contact economizers, to increase the surface of heat and mass transfer, it is advisable to use various types of nozzles. The aim of the study is to develop such an indicator, with which it is possible to determine the optimal type of nozzle of the contact economizer installed after the steam boiler. This indicator should show the highest heat engineering efficiency of the packing with a small hydraulic resistance of the heat exchanger. By using the coefficient of specific energy efficiency of the packing in the heat exchanger of waste gases of heating equipment, it is possible to analyze the work of the packing space from the standpoint of thermal and hydraulic efficiency and select the optimal type of packing for each individual unit or installation. Geometric parameters determine the required volume of the apparatus and the hydraulic resistance of the exhaust gases movement. The hydraulic resistance affects the consumption of electrical energy for the drive of smoke exhausters for sucking off exhaust gases from heat engineering installations through the free section of the heat exchanger. Taking into account the developed indicator of the specific energy efficiency in waste heat utilizers, it is possible to select such a type of packing, at which the optimal level of waste heat utilization will be achieved.

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17

Savoldi, Laura, Konstantinos A. Avramidis, Ferran Albajar, Stefano Alberti, Alberto Leggieri, and Francisco Sanchez. "A Validation Roadmap of Multi-Physics Simulators of the Resonator of MW-Class CW Gyrotrons for Fusion Applications." Energies 14, no. 23 (December 1, 2021): 8027. http://dx.doi.org/10.3390/en14238027.

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For a few years the multi-physics modelling of the resonance cavity (resonator) of MW-class continuous-wave gyrotrons, to be employed for electron cyclotron heating and current drive in magnetic confinement fusion machines, has gained increasing interest. The rising target power of the gyrotrons, which drives progressively higher Ohmic losses to be removed from the resonator, together with the need for limiting the resonator deformation as much as possible, has put more emphasis on the thermal-hydraulic and thermo-mechanic modeling of the cavity. To cope with that, a multi-physics simulator has been developed in recent years in a shared effort between several European institutions (the Karlsruher Institut für Technologie and Politecnico di Torino, supported by Fusion for Energy). In this paper the current status of the tool calibration and validation is addressed, aiming at highlighting where any direct or indirect comparisons with experimental data are missing and suggesting a possible roadmap to fill that gap, taking advantage of forthcoming tests in Europe.

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18

Posmetev, Valeriy, Vadim Nikonov, Viktor Posmetev, and Vladimir Zelikov. "COMPUTER SIMULATION RESULTS OF FUNCTIONING OF THE PNEUMATIC SUBSYSTEM OF RECOVERABLE HYDRAULIC DRIVE OF A FOREST TRUCK WITH A SEMI-TRAILER." Forestry Engineering Journal 10, no. 1 (April 6, 2020): 233–43. http://dx.doi.org/10.34220/issn.2222-7962/2020.1/17.

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The relevance of developing new devices for accumulation and conversion of compressed air energy in a regenerative hydraulic drive of a timber truck with a semitrailer has been substantiated. The layout of recuperative mechanisms on a timber tractor with a semitrailer and the diagram of a recuperative hydraulic drive with subsystems for accumulating and converting compressed air energy are presented. A simplified diagram of a pneumatic energy-saving system for studying the functioning of the subsystems of accumulation and energy conversion of compressed air is presented. A mathematical model has been developed to evaluate the efficiency of using a pneumatic energy-saving system, which includes the equations of change in the gas state in its elements, solved by the Euler numerical method. A modeling algorithm is described, consisting of seven repeating steps performed in the process of computer simulation. The developed computer program is presented, which allows studying pneumatic energy-saving system. Computer experiments with the most typical set of its design and technological parameters are presented. The time dependences of the volume of the pneumatic cavities under consideration, the amount of substance in them, pressure and air temperature in the pneumatic cavities under consideration are obtained. The influence of the diameter of the pneumatic cylinder on the filling time of the receiver, the number of strokes of the piston and thermal efficiency has been defined

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19

Sevostianov, Ivan, and Yaroslav Ivanchuck. "MODELLING OF WORKING PROCESS OF EQUIPMENT WITH HYDRAULIC DRIVE FOR SEPARATION OF DAMP DISPERSIVE MATERIALS." ENGINEERING, ENERGY, TRANSPORT AIC, no. 1(116) (April 29, 2022): 77–82. http://dx.doi.org/10.37128/2520-6168-2022-1-9.

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A task of introduction of separation processes of damp dispersive materials are very actual for food and processing industry of Ukraine and other countries, because its solution will allow to resolve by most effective way a problem of utilization of such waste as alcoholic bard, beer pellets, beet press, coffee and barley slime. In most cases this waste is poured out in nearest reservoirs or on ground and that leads to environment pollution. But after separation from the waste of the liquid phase (waste dehydration) its hard phase can be used as a valuable additive to agricultural fodders or as a high calorie fuel. By article’s authors notion the most prospective method of separation of the damp dispersive waste is mechanical dehydration, that provides high productivity of the working process, low consumption of energy (in 240 – 800 times lower then under realization of thermal methods) and necessary final humidity of the waste (20 – 25% in case of utilization by a method of vibro-blowing dehydration). One of the most prospective types of equipment for mechanical separation of the damp dispersive waste are presses with hydraulic drive that have relatively compact dimensions, high energy efficiency and reliability and provide a possibility for wide-range and infinitely variable control of main parameters of a loading regime of the waste processing. There is a scheme of an improved and high effective installation with hydraulic drive for separation of damp dispersive materials is presented in the article. Besides there are elaborated equations of its mathematic model that connect working parameters of separation, design parameters of the installation and physical-mechanical characteristics of the processed material. These equations can be used for optimization of the installation’s design and for creation of its method of projecting calculation.

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20

Yu, Qiang, Xuesong Wang, and Yuhu Cheng. "Electromagnetic and thermal coupled analysis of can effect of a novel canned switched reluctance machine as a hydraulic pump drive." International Journal of Applied Electromagnetics and Mechanics 54, no. 1 (April 19, 2017): 131–40. http://dx.doi.org/10.3233/jae-160126.

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21

Tiunov, S. V., A. N. Skrypnik, G. S. Marshalova, V. M. Gureev, I. A. Popov, R. G. Kadyrov, A. D. Chorny, and Y. V. Zhukova. "Experimental Investigation of Thermal and Hydraulic Characteristics of Finned Flat Tubes of the Oil Air Cooling Device." ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 63, no. 2 (March 27, 2020): 138–50. http://dx.doi.org/10.21122/1029-7448-2020-63-2-138-150.

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Air cooling devices are heat exchange units that are widely used in practice. However, they have a number of disadvantages due to the low value of the heat transfer coefficient from the air and the high resistance of finned tube bundles, which leads to large dimensions and the metal content of the device itself, to the need to develop a high power ventilator drive, but also to the need to demonstrate reduced energy efficiency. The objective of the present work is to determine optimal geometric sizes of finned flat heat exchange tubes manufactured by the techniques of extrusion and deforming cutting that reduce the weight and size characteristics of the heat exchange section of air cooling devices. The experimental studies of seven various samples of heat exchange sections, being different in fin pitch and height, tube section width, flat tube height and a number of inner channels, have determined the performance of each section with the use of the following criteria: thermal power, thermal efficiency, specific thermal heat transfer resistance, M. V. Kirpichev and V. M. Antuf’ev’s criteria. The obtained experimental data and the analysis of the passive method of enhancement in the near-wall area of the heat transfer surface finned by deforming cutting has shown that sample No 5 has maximum value of the performance criteria when the maximum height of a fin is 0.008 m and the minimum pitch of a fin is 0.0025 m over the investigated sample range. Thus, when the sizes of an oil air cooling device are maintained by using the amended heat transfer section of sample No 5, the amount of removed heat can be increased or the mass and dimensions of the device can be decreased while maintaining thermal power and, as a result, the power consumption for pumping can be decreased and the thermal-hydraulic performance of the device as a whole can be increased.

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22

Usoltsev, S. F., V. S. Nestyak, O. V. Ivakin, G. V. Nestyak, and Yu V. Goncharenko. "Feasibility evaluation of the ventilation control mechanism drive of a large screen canopy." Siberian Herald of Agricultural Science 49, no. 3 (July 23, 2019): 79–86. http://dx.doi.org/10.26898/0370-8799-2019-3-10.

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The study was carried out on how to enhance the effectiveness of solar energy and reduce technological risks connected with growing large-fruited tall tomato varieties in conditions of insufﬁ cient heat supply by using automatically controlled inﬂ ow-and-exhaust ventilation. High probability of late recurring and early autumn frosts in Western Siberia poses a threat of complete harvest loss of thermophilic vegetable crops. Improvement of the heat supply during the growing period is possible due to the greenhouse effect occurring in canopies and greenhouses. In summer, additional energy creates the danger of overheating, which can be eliminated by an automatically controlled inﬂ ow-and-exhaust ventilation. Laboratory experiments showed that the automatic device consistently maintains air temperature within 26-27°C, which meets biological requirements of plants, by changing the width of the exhaust air aperture. Opening of the inﬂ ow air aperture increases the intensity of air ﬂ ow inside the canopy. The hydraulic drive of the ventilation control mechanism consistently maintains the air temperature inside the canopy in the process of heating by means of automatic regulation of exhaust air aperture width, but it is ineffective in the cooling process due to high thermal inertia. Changing the height of the inﬂ ow air aperture from 0 to 0.3 m makes the intensity of air exchange increase and the air temperature decrease.

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23

Rybár, Radim, and Martin Beer. "Application potential analysis of heat accumulator for mining mechanisms." E3S Web of Conferences 134 (2019): 01021. http://dx.doi.org/10.1051/e3sconf/201913401021.

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The paper deals with the application potential analysis of heat accumulators for mining machines working in cold climatic conditions. The proposed concept works with the idea of accumulating waste heat generated by the operation of an internal combustion engine, with use of exhaust heat, heat from the radiator and heat from the drive of the hydraulic system. An important innovative element is the use of the heterogeneous structure of phase change material - sodium acetate as a storage substance and a metal foam matrix. The use of sodium acetate enable to store heat for a long period of time without heat loss and the metal foam matrix significantly increases the thermal conductivity. The presented paper deals with the analysis of the functionality of the heat accumulator prototype and with the description of the key phase of the working cycle - heat accumulation.

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Pokusaev, Mikhail Nikolaevich, Alexei Viktorovich Trifonov, and Vasiliy Aleksandrovich Kostyrenko. "Developing cooling system for small-sized marine diesel engines operating at different seawate temperatures in laboratory conditions." Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies 2022, no. 2 (May 31, 2022): 51–57. http://dx.doi.org/10.24143/2073-1574-2022-2-51-57.

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Using a cooling system in water transport is considered the most effective way to increase the energy efficiency of a vessel. Currently, closed-loop cooling systems and frequency-controlled drives of seawater electric pumps are actively used. An option of improving the energy efficiency of cooling systems with mounted seawater pumps is being studied. The hydraulic scheme of the unit with an energy-efficient ship engine cooling system is presented. To study ways to reduce mechanical losses in the drive of auxiliary mechanisms of a marine engine, the laboratory “Marine Diesels” of Astrakhan State Technical University developed a test bench for the Iveco 8041I06 engine. The engine cooling system does not have a thermostat to control the thermal state; instead of a thermostat on the engine, an electronically controlled variator is installed between the engine power take-off shaft and the VKS 1/16 pump. At a constant engine speed, the variator allows changing the pump speed, supply of sea water through the heat exchanger and regulating the thermal state of the engine. It has been found that during engine tests it is necessary to maintain the temperature of the outboard water constant. A description is given of the use of tanks with thermal insulation at the stand to reduce heat exchange with the environment. Variants of types of containers and materials for insulation are considered. To prepare water of the required temperature a chiller is connected to the cooling system at the experimental stand. The calculation of thermal insulation and comparison of the result with a real test is given. On the stands for testing diesel engines the change in the thermal state of the engine is carried out only by changing the load on the engine. On the developed stand, the thermal state can also be changed, including by controlling the seawater temperature, which expands its capabilities for modeling real processes.

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Han, Chulhee, Seung-Bok Choi, and Young-Min Han. "A Piezoelectric Actuator-Based Direct-Drive Valve for Fast Motion Control at High Operating Temperatures." Applied Sciences 8, no. 10 (October 2, 2018): 1806. http://dx.doi.org/10.3390/app8101806.

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This paper experimentally investigates the control performances of a piezostack actuator direct-drive valve (PADDV) operating at high temperatures. In this study, the PADDV system is designed based on special specifications featuring a high operating temperature (150 °C) and wide control bandwidth (200 Hz). After manufacturing the PADDV with design limitations such as size and maximum input voltage to the piezostack actuator, the displacement of a spool located inside the valve system, which is directly related to the flow rate, is controlled at several different temperatures and motion frequencies. In order to undertake this, the PADDV system is installed inside a heat chamber equipped with air vessels and pneumatic–hydraulic cylinders. The piezoelectric actuator is partially insulated using an aerogel to prevent permanent damage due to high temperatures above 120 °C, which is higher than the Curie temperature. To control the valve system, a PID (proportional–integral–derivative) controller is realized in which control gains are properly tuned using fuzzy logic according to the change of temperature and frequency. It is shown from the experimental results that the proposed PADDV with thermal insulation can provide the target dynamic motion of 200 Hz at 150 °C by implementing the fuzzy-based PID controller.

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26

Tom, Liya, Muhammad Khowja, Gaurang Vakil, and Chris Gerada. "Commercial Aircraft Electrification—Current State and Future Scope." Energies 14, no. 24 (December 13, 2021): 8381. http://dx.doi.org/10.3390/en14248381.

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Electric and hybrid-electric aircraft propulsion are rapidly revolutionising mobility technologies. Air travel has become a major focus point with respect to reducing greenhouse gas emissions. The electrification of aircraft components can bring several benefits such as reduced mass, environmental impact, fuel consumption, increased reliability and quicker failure resolution. Propulsion, actuation and power generation are the three key areas of focus in more electric aircraft technologies, due to the increasing demand for power-dense, efficient and fault-tolerant flight components. The necessity of having environmentally friendly aircraft systems has promoted the aerospace industry to use electrically powered drive systems, rather than the conventional mechanical, pneumatic or hydraulic systems. In this context, this paper reviews the current state of art and future advances in more electric technologies, in conjunction with a number of industrially relevant discussions. In this study, a permanent magnet motor was identified as the most efficient machine for aircraft subsystems. It is found to be 78% and 60% more power dense than switch-reluctant and induction machines. Several development methods to close the gap between existing and future design were also analysed, including the embedded cooling system, high-thermal-conductivity insulation materials, thin-gauge and high-strength electrical steel and integrated motor drive topology.

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27

Pyatin, Andrey, Aleksander Shempelev, and Ekaterina Popova. "Improving the efficiency of heating boiler plants by using the variable-frequency drive with different methods of heat supply regulation." MATEC Web of Conferences 245 (2018): 07020. http://dx.doi.org/10.1051/matecconf/201824507020.

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The aim of the work is to improve the energy efficiency of heating boiler plants by reducing the spe-cific electric energy consumption for heat supply by using the variable-frequency drive (VFD) with different methods of heat supply regulation. Hydraulic and thermal calculations of the heating net-work are performed on the example of the real district heating system. Heat network temperature charts of district heating are selected and calculated considering preservation of high quality of district heating. The description of the calculation algorithm of the research and the results of the calculation of the basic mode of district heating heat supply according to the standard temperature chart of varia-ble temperature control are given in the article. Places of installation of VFD are determined on the base of the basic mode. The results of calculation of three different methods of heat supply regulation are presented: standard heat network temperature chart of variable temperature control with using the VFD, extended heat network temperature chart of constant temperature/variable flow control, extend-ed heat network temperature chart using the VFD.

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28

Moska, Rafał, Krzysztof Labus, and Piotr Kasza. "Hydraulic Fracturing in Enhanced Geothermal Systems—Field, Tectonic and Rock Mechanics Conditions—A Review." Energies 14, no. 18 (September 11, 2021): 5725. http://dx.doi.org/10.3390/en14185725.

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Hydraulic fracturing (HF) is a well-known stimulation method used to increase production from conventional and unconventional hydrocarbon reservoirs. In recent years, HF has been widely used in Enhanced Geothermal Systems (EGS). HF in EGS is used to create a geothermal collector in impermeable or poor-permeable hot rocks (HDR) at a depth formation. Artificially created fracture network in the collector allows for force the flow of technological fluid in a loop between at least two wells (injector and producer). Fluid heats up in the collector, then is pumped to the surface. Thermal energy is used to drive turbines generating electricity. This paper is a compilation of selected data from 10 major world’s EGS projects and provides an overview of the basic elements needed to design HF. Authors were focused on two types of data: geological, i.e., stratigraphy, lithology, target zone deposition depth and temperature; geophysical, i.e., the tectonic regime at the site, magnitudes of the principal stresses, elastic parameters of rocks and the seismic velocities. For each of the EGS areas, the scope of work related to HF processes was briefly presented. The most important HF parameters are cited, i.e., fracturing pressure, pumping rate and used fracking fluids and proppants. In a few cases, the dimensions of the modeled or created hydraulic fractures are also provided. Additionally, the current state of the conceptual work of EGS projects in Poland is also briefly presented.

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Bousquet, Jeremy, Romain Henry, and Armin Seubert. "3-D TRANSIENT COUPLED SIMULATION OF SUPERPHENIX WITH PARCS/ATHLET." EPJ Web of Conferences 247 (2021): 06034. http://dx.doi.org/10.1051/epjconf/202124706034.

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Most safety criteria for Sodium cooled Fast Reactors (SFR) are local core parameters. Thus, application of 3-D neutron kinetic and thermal-hydraulic coupled codes including detailed modelling of core expansion effects is mandatory for best estimate evaluations of safety margins. A recently published benchmark based on measurements performed at the Superph´enix (SPX) reactor offers the opportunity to validate codes and methods for SFR safety assessment. In this paper, the SPX core is modelled in ATHLET and PARCS. Explicit models for axial and radial core expansion effects for 3-D coupled calculations were recently implemented in PARCS. In ATHLET, axial thermal expansion of structures (strongback, vessel, control rod drive line) influencing the relative position of the control rod in the active core is modelled. The newly implemented models are tested on a transient initiated by a reactivity insertion of -50 pcm. A point kinetic simulation is also performed to compare with the 3D solution. Both ATHLET-point kinetic model and ATHLET-PARCS simulations deliver similar power responses during the transient but with an offset. By analysing the different feedbacks in the point kinetic model, it can be concluded that models of expansion of the different structures are well implemented. In the future further analysis of different transients of the benchmark are planned.

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Han, Linghai, Jiaquan Duan, Dingchao Qian, Yanfeng Gong, Yaodong Wang, Fangxi Xie, and Yan Su. "Research on Homogeneous Charge Compression Ignition Combustion of Intake Port Exhaust Gas Recirculation Based on Cam Drive Hydraulic Variable Valve Actuation Mechanism." Energies 15, no. 2 (January 8, 2022): 438. http://dx.doi.org/10.3390/en15020438.

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The thermal efficiency of an efficient gasoline engine is only about 40% and it will produce a large number of harmful products. Curbing harmful emissions and enhancing thermal efficiency have always been the goals pursued and emission regulations are also being tightened gradually. As one of the main consumers of fossil fuels, automobile engines must further reduce fuel consumption and emissions to comply with the concept of low-carbon development, which will also help them compete with electric vehicles. Homogeneous charge compression ignition (HCCI) combustion combined with variable valve actuation (VVA) technology is one of the important ways to improve engine emissions and economy. HCCI combustion based on VVA can only be realized at small and medium loads. The actual application on the entire vehicle needs to be combined with spark ignition (SI) combustion to achieve full working condition coverage. Therefore, HCCI combustion needs fast valve response characteristics; however, the valve lift and timing of the existing VVA mechanisms are mostly controlled separately, resulting in poor valve response. In order to solve this problem, the cam driven hydraulic variable valve actuation (CDH-VVA) mechanism was designed. The valve lift and timing can be adjusted at the same time and the switching of valve lift and timing can be completed in 1~2 cycles. A set of combustion mode switching data is selected to show the response characteristics of the CDH-VVA mechanism. When switching from spark ignition (SI) to HCCI, it switches to HCCI combustion after only one combustion cycle and it switches to stable HCCI combustion after two combustion cycles, which proves the fast response characteristics of the CDH-VVA mechanism. At the same time, the CDH-VVA mechanism can form the intake port exhaust gas recirculation (EGR), as one type of internal EGR. This paper studies the HCCI combustion characteristics of the CDH-VVA mechanism in order to optimize it in the future and enable it to realize more forms of HCCI combustion. At 1000 rpm, if the maximum lift of the exhaust valve (MLEV) is higher than 5.0 mm or lower than 1.5 mm, HCCI combustion cannot operate stably, the range of excess air coefficient (λ) is largest when the MLEV is 4.5 mm, ranging from 1.0~1.5. Then, as the MLEV decreases, the range of λ becomes smaller. When the MLEV drops to 1.5 mm, the range of λ shortens to 1.0~1.3. The maximum value of the MLEV remains the same at the three engine speeds (1000 rpm, 1200 rpm and 1400 rpm), which is 5.0 mm. The minimum value of the MLEV gradually climbs as the engine speed increase, 1000 rpm: 1.5 mm, 1200 rpm: 2.0 mm, 1400 rpm: 3.0 mm. With the increase of engine speed, the range of indicated mean effective pressure (IMEP) gradually declines, 3.53~6.31 bar (1000 rpm), 4.11~6.75 bar (1200 rpm), 5.02~6.09 bar (1400 rpm), which proves that the HCCI combustion loads of the intake port EGR are high and cannot be extended to low loads. The cyclic variation of HCCI combustion basically climbs with the decrease of the MLEV and slightly jumps with the increase of the engine speed. At 1000 rpm, when the MLEV is 5.0 mm, the cyclic variation range is 0.94%~1.5%. As the MLEV drops to 1.5 mm, the cyclic variation range rises to 3.5%~4.5%. Taking the maximum value of the MLEV as an example, the cyclic variation range of 1000 rpm is 0.94%~1.5%, 1200 rpm becomes 1.5%~2.3% and 1400 rpm rises to 2.0%~2.5%.

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Anastasakis, Konstantinos, Patrick Biller, René Madsen, Marianne Glasius, and Ib Johannsen. "Continuous Hydrothermal Liquefaction of Biomass in a Novel Pilot Plant with Heat Recovery and Hydraulic Oscillation." Energies 11, no. 10 (October 10, 2018): 2695. http://dx.doi.org/10.3390/en11102695.

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Hydrothermal liquefaction (HTL) is regarded as a promising technology for the production of biofuels from biomass and wastes. As such, there is a drive towards continuous-flow processing systems to aid process scale-up and eventually commercialization. The current study presents results from a novel pilot-scale HTL reactor with a feed capacity of up to 100 L/h and a process volume of approximately 20 L. The pilot plant employs a heat exchanger for heat recovery and a novel hydraulic oscillation system to increase the turbulence in the tubular reactor. The energy grass Miscanthus and the microalgae Spirulina, both representing advanced dedicated energy crops, as well as sewage sludge as high-potential waste stream were selected to assess the reactor performance. Biomass slurries with up to 16 wt% dry matter content were successfully processed. The heat recovery of the heat exchanger is found to increase with reactor run time, reaching 80% within 5–6 h of operation. The hydraulic oscillation system is shown to improve mixing and enhance heat transfer. Bio-crudes with average yields of 26 wt%, 33 wt% and 25 wt% were produced from Miscanthus, Spirulina and sewage sludge, respectively. The yields also appeared to increase with reactor run time. Bio-crude from HTL of Spirulina was mainly composed of palmitic acid, glycerol, heptadecane and linolelaidic acid, while biocrude from sewage sludge contained mainly palmitic acid, oleic acid and stearic acid. In contrast, biocrude from HTL of Miscanthus consisted of a large number of different phenolics. An energetic comparison between the three feedstocks revealed a thermal efficiency of 47%, 47% and 33% and energy return on investment (EROI) of 2.8, 3.3 and 0.5 for HTL of Miscanthus, Spirulina and sewage sludge, respectively.

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Cook, C. C., M. A. Andersen, G. Halle, E. Gislefoss, and G. R. Bowen. "An Approach to Simulating the Effects of Water-Induced Compaction in a North Sea Reservoir (includes associated papers 73134 and 73135 )." SPE Reservoir Evaluation & Engineering 4, no. 02 (April 1, 2001): 121–27. http://dx.doi.org/10.2118/71301-pa.

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Summary Rock-compaction drive under waterflood re-pressurization has not been accounted for previously in our flow-model studies for a Valhall waterflood. However, field observations from pilot waterfloods indicate an increase in permeability with the injection of cool seawater into the chalk formation. Platform subsidence measurements taken during the pilot waterflood also provide evidence of a chalk/water interaction. Laboratory experiments on reservoir core samples indicate an accelerated compaction effect as the flood front passes through the sample. To assess the value of a large-scale waterflood at Valhall, we have developed a new approach to simulate the possible effects of water-induced rock compaction in our black-oil flow models. Introduction Rock-compaction drive induced by pressure decline is estimated to contribute 50% of the oil recovery from the Valhall Cretaceous Age chalk reservoir under primary depletion.1 The tremendous natural energy coming from pressure-induced rock-compaction drive has led to a delay in waterflood plans at Valhall. However, as reported by Andersen et al.,2 laboratory tests on Valhall cores indicate vertical compaction caused by the introduction of water under constant stress conditions. Piau and Maury3 relate the disciplines of soil mechanics and petroleum engineering relative to the weakening/induced compaction effects of water on chalk. Further, as reported by Chin and Prevost,4 the weakening effect of water on chalk compaction may make waterflooding more economically favorable for improving oil recovery from some North Sea chalk reservoirs. Water-Induced Rock Compaction Compaction drive from pressure depletion significantly contributes to oil recoveries in both the Valhall and Ekofisk fields.1,5 It was previously believed that the mechanism to invoke compaction was exclusively related to pressure depletion. However, field and laboratory experience point to the fact that compaction may also occur from chalk/water interaction, even at constant stress. We no longer believe that reservoir-pressure maintenance with water injection will arrest compaction. The question now is whether water weakening only accelerates compaction or increases ultimate compaction.4 A Physical Picture. Fig. 1schematically illustrates in simple terms the Valhall chalk reservoir in the form of a cube in its initial state, followed by primary depletion and then waterflood. Primary Depletion. Under primary depletion, the chalk cube's temperature remains constant while its pressure is lowered (see Fig. 1). Plastic deformation occurs, which at Valhall is believed to be caused by pore collapse. The chalk cube shrinks and the natural fractures heal (i.e., permeability reduction). Waterflood. The chalk cube is then injected with cool seawater, whereby its temperature is lowered and pressure is increased. According to Perkins and Gonzalez6 and Teufel and Rhett,7 the stress state of the core is altered so that the average effective stress decreases while maintaining a constant shear stress(i.e., weight of the overburden). The decreased stress state may be compared to a loss of strength. Again, Fig. 1 shows that the waterflood result is a further collapse of the chalk cube. However, permeability is slightly increased owing to induced fracturing. Physics. As reported by Maury et al.,8 typical chalks from Valhall field are very pure, made up of 98 to 100% calcium carbonate, without any secondary minerals. When a waterflood passes through this type of chalk it can generate compaction. The compaction is localized to the flood front, but decays slowly with time after the front passes. The effect is greater if the chalk is in a plastic state. We do not know the microscopic physical mechanism associated with the compaction, but it is believed to be associated with capillary pressure effects. The increased water saturation disturbs the capillary forces, destabilizing the chalk and causing it to compact. The additional deformation induced by water saturation has been described in a constitutive theoretical analysis of chalk.8 Fractures. As described by Andersen9 and illustrated in Fig. 2, when the flood front passes through, the chalk may compact and fracture. Perkins and Gonzalez10 describe the similar cool-water fracturing as secondary fractures resulting from changes in the in-situ stress. Teufel and Rhett7 report large increases in reservoir permeability measured in well tests conducted before and after waterflooding, indicating the extensive nature of waterflood-induced fracturing at Ekofisk. Hydraulic Fractures. The fractures resulting from water-induced compaction are distinct from the hydraulic fractures created as a result of injecting above formation parting pressure. Both types of fracturing significantly contribute to flow conductivity, but hydraulic fractures are confined to the injection well areas and are believed to open and close based on bottomhole injection pressure. Thermal Effects. Charlez et al.11 explain the two main offsetting effects of cooling on the mechanical behavior of chalk during water injection. The first effect is a stiffening or strengthening of the material with decreasing temperature. The second effect is thermal contraction of both the solid and the fluid, which induces thermal stresses. The overall thermal waterflood effect on the mechanical behavior of North Sea chalk is not conclusively determined and warrants further investigation. Valhall Field The Valhall field is located within the North Sea Central graben consisting of late Cretaceous Age rock. The field structure is an asymmetrical dome with a relatively steep western flank resulting from basin inversion along a regional fault system known as the Lindesnes fault. Reservoir depth is 2400 m subsea with a free water level at 2630 m subsea. Initial reservoir temperature and pressure were 195°F and 6600 psia, respectively. The reservoir consists of two formations, the Tor and Hod. Initial rock porosities in the Tor generally range from 40 to 50%; porosities in the Hod formation are lower, ranging from 25 to 40%. The main reason for the preservation of such high porosity is believed to be the early migration of oil into the coccolith pore space before significant burial. One might say that over the years the oil has acted as an embalming fluid, protecting the chalk body from porosity decay.

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Levtsev, Alexey P., and Anatoly I. Lysyakov. "Energy-Independent Heating System with Improved Energy Efficiency for Agricultural Premises." Engineering Technologies and Systems 32, no. 1 (March 30, 2022): 110–25. http://dx.doi.org/10.15507/2658-4123.032.202201.110-125.

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Introduction. The article is concerned with increasing the efficiency of energy-independent heat supply systems in agriculture through using a heat recovery unit with a thermomechanical energy converter. The most promising is a thermomechanical energy converter with a thermodynamic cycle of periodic action to drive a diaphragm pump. For heaters and boilers, the use of pulsating mode of the heat carrier has a double effect: it increases heat transfer and reduces the formation of deposits on the heat transfer surfaces. Materials and Methods. Using the thermodynamic method and the possibilities of impulse technologies, a thermodynamic cycle and a device of periodic action were proposed. In this device, three thermodynamic processes are sequentially implemented: isochoric heating and evaporation of the working substance, adiabatic performance of work, and isobaric condensation. Thermodynamic cycles are constructed for five known working substances (R11; R21; R113; R114; R123) on lgP-h thermodynamic state diagrams and their parameters at characteristic points are calculated. Results. There has been performed frequency matching of the thermal-mechanical converter with the hydraulic parameters of the heat source and heat-consuming unit. Such matching was based on the frequency responses. To describe the hydrodynamics of the heat supply system, a system of differential equations with constant coefficients was used, which was solved using the Laplace transformation. A rational frequency of oscillations of the heat carrier flow was determined within the range of 1.38–2.76 rad/s. Discussion and Conclusion. A scheme of a heat supply system with the independent connection of the heat-consuming unit to a heat source is proposed. On the example of a heat source with a power of 100 kW, graphical dependences of the heat source minimum pressures on the change in the consumption of a heat carrier and the active hydraulic resistance of the heat network are obtained. An algorithm for determining the power increment from the use of a heat exchanger with a thermomechanical converter is proposed. It has been determined that the efficiency of the heat recovery unit will be higher for low-power boilers.

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Escobar, Freddy Humberto, Angela Patricia Zambrano, Diana Vanessa Giraldo, and José Humberto Cantillo. "Pressure and pressure derivative analysis without type-curve matching for thermal recovery processes." CT&F - Ciencia, Tecnología y Futuro 4, no. 4 (December 1, 2011): 23–35. http://dx.doi.org/10.29047/01225383.226.

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In recent years, a constant increase of oil prices and declining reserves of coventional crude oils have produced those deposits of lights to be considered economically unattractive to be produced as an alternative way to keep the world´s oil supply volume. Heavy oil deposits are mainly characterized by having high resistance to flow (high viscosity), which makes them diffi-cult to produce. Since oil viscosity is a property that is reduced by increasing the temperature, thermal recovery techniques -such as steam injection or in-situ combustion- have become over the years the main tool for tertiary recovery of these oils. Composite reservoirs can occur naturally or may be artificially created. Changes in reservoir width, facies or type of fluid (hydraulic contact) forming two different regions are examples of two-zone composite reservoirs occurring naturally. On the other hand, such enhanced oil recovery projects as waterflooding, polymer floods, gas injection, in-situ combustion, steam drive, and CO2 miscible artificially create conditions where the reservoir can be considered as a composite system. A reservoir undergoing a thermal recovery process is typically idealized as a two-zone composite reservoir, in which, the inner region represents the swept region surrounding the injection well and the outer region represents the larger portion of the reservoir. Additionally, there is a great contrast between the mobilities of the two zones and the storativity ratio being different to one. In this work, the models and techniques developed and implemented by other authors have been enhanced. Therefore, the interpretations of the well tests can be done in an easier way, without using type-curve matching. A methodology which utilizes a pressure and pressure derivative plot is developed for reservoirs subjected to thermal recovery so that mobilities, storativity ratio, distance to the radial discontinuity or thermal front and the drainage area can be estimated. The precedence of the heat source (in-situ combustion or hot injected fluids) does not really matter for the application of this methodology; however, this was successfully verified by its application to synthetic and field examples of in-situ combustion. The point of comparison was the input data used for simulation for the synthetic case and the results from simulation matching and from previous studies for the field cases.

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Abarca, A., M. Avramova, K. Ivanov, S. Verdebout, D. De Meyer, and C. R. Schneidesch. "DEVELOPMENT AND VERIFICATION OF T-TRACE/PANTHER COUPLED CODE." EPJ Web of Conferences 247 (2021): 06027. http://dx.doi.org/10.1051/epjconf/202124706027.

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Multi-physics coupled simulations have become increasingly important during the last two decades being one of the major field of application in the nuclear technology. The nuclear reactors themselves are complex systems whose responses are driven by interactions between neutron kinetics, thermal-hydraulics, heat transfer, mechanics and chemistry. Probably, in a nuclear system, the most complex and important feedback effect takes place between the core neutron kinetics and thermal-hydraulics. The development of coupled thermal-hydraulic -neutron kinetics codes is a recurrent field of research for the nuclear industry. This contribution, developed in the Consortium for Nuclear Power (CNP) framework, has the objective of develop a dynamic coupling, using TCP/IP based socket communication, between the thermal-hydraulic system code T-TRACE, Tractebel-ENGIE version of the latest US NRC TRACE release, and the multi-group 3-D nodal diffusion and core physics code PANTHER, developed and maintained by EDF Energy (UK). As a first step of the development, a fully temporally explicit coupling scheme has been developed between TRACE and PANTHER based on a boundary conditions exchange at the core level at each temporal iteration. The OECD TMI MSLB benchmark has been selected as verification scenario for testing the ongoing developing T-TRACE/PANTHER coupled code. The developed coupled code is benchmarked code-to-code against TRACE/PARCS and T-RELAP5/PANTHER.

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Ulyanov, V. Y. "Ways to Increase the Efficiency of Thermopressiometry." Science and Transport Progress. Bulletin of Dnipropetrovsk National University of Railway Transport, no. 2(92) (April 15, 2021): 84–91. http://dx.doi.org/10.15802/stp2021/237279.

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Purpose. The purpose of the work is to identify the ways to increase the efficiency of engineering research, based on the significant amount of exploration work required in the creation of modern man-made objects, taking into account the shortcomings of existing instruments and equipment used to measure soil stress, and in relation to the need to improve the design of thermopressiometers, which are aimed to facilitate the study of frozen soils. Methodology. The ways to improve the blade thermopressiometer for the study of frozen soils with different aggregates were selected by the comparative-analytical method and the method of analogy. Thawing depth, absolute soil sediment, deformation modulus etc. were determined by thermal-technical calculations. Findings. The application issues of concern of the existing thermopressiometers (limited research of soils of a certain type, complexity and insufficient accuracy of readings) identified can be overcome by the proposed improved design of a blade thermopressiometer for testing frozen sandy-clay soils. It is based on the improved heating circuit, the applicationd of quality materials and changing the form of the blades and body. The device is intented for use on permafrost and natural frozen soils of the world, including Ukraine. Originality. For the first time we offered a model of an advanced thermopressiometer with an improved body shape made of high-quality corrosion-resistant materials, including non-metallic ones. It has the reduced number of blades to one retractable sector blade-stamp (square or round) and one heating blade-stamp. A special probe design with mechanical/hydraulical sensor drive with a thermocouple (or with two fork probes to improve the measurements) was proposed. It was also recommended to introduce an electric conductive system designed for thawed soils, with a rod for measuring the retractable blade-stamp. The possibility of using a thermopressiometer during the study of seasonally frozen soils is established. Practical value. Improving the device model should facilitate its application in engineering and geological research for various types of construction, including transport, hydraulic engineering, which use the methods of deep freezing of weak and unstable soils.

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Jasiński, Ryszard. "Problems of the starting and operating of hydraulic units and systems in low ambient temperature (Part I)." Polish Maritime Research 15, no. 4 (January 1, 2008): 37–44. http://dx.doi.org/10.2478/v10012-007-0095-9.

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Problems of the starting and operating of hydraulic units and systems in low ambient temperature (Part I) Severe winters and sweltering summers which more and more often occur nowadays are the reason why machinery designers face many difficulties when designing devices which will be serviceable in extreme ambient conditions. Hence, defining the principles and conditions of safe operation of hydraulically driven machines and devices is essential for their designers and operators. For this reasons the author did a series of tests of hydraulic component and systems in thermal shock conditions (cooled-down component were supplied with hot working medium). In such conditions, starting parameters of the selected hydraulic component and systems which secured safety of their operation were determined. The experimental tests were carried out in the laboratory of the Chair of Hydraulics and Pneumatics, Gdańsk University of Technology.

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Minhat, Mohd Sabri, Nurul Adilla Mohd Subha, Fazilah Hassan, and Norjulia Mohamad Nordin. "An improved control rod selection algorithm for core power control at TRIGA PUSPATI Reactor." Journal of Mechanical Engineering and Sciences 14, no. 1 (March 23, 2020): 6362–79. http://dx.doi.org/10.15282/jmes.14.1.2020.13.0498.

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The 1 MWth TRIGA PUSPATI Reactor known as RTP undergoes more than 37 years of operation in Malaysia. The current core power control utilized Feedback Control Algorithm (FCA) and a conventional Control Rod Selection Algorithm (CRSA). However, the current power tracking performance suffers and increase the workload on Control Rod Drive Mechanism (CRDM) if the range between minimum and maximum rod worth value for each control rod has a significant difference. Thus, it is requiring much time to keep the core power stable at the power demand value within the acceptable error bands for the safety requirement of the RTP. In conventional CRSA, regardless of the rod worth value, the lowest position of the control rod is selected for up-movement to regulate the reactor power with 2% chattering error. To improve this method, a new CRSA is introduced named Single Control Absorbing Rod (SCAR). In SCAR, only one rod with highest reactivity worth value will be selected for coast tuning during transient and the lowest reactivity worth value will be selected for fine-tuning rod movement during steady-state. The simulation model of the reactor core is represented based on point kinetics model, thermal-hydraulic models and reactivity model. The conventional CRSA model included with control rod position dynamic model and actual reactivity worth curve data from RTP. The FCA controller is designed based on Proportional-Integral (PI) controller using MATLAB Simulink simulation. The core power control system is represented by the integration of a reactor core model, CRSA model and FCA controller. To manifest the effectiveness of the proposed SCAR algorithm, the results are compared to the conventional CRSA in both simulation and experimentation. Overall, the results shows that the SCAR algorithm offers generally better results than the conventional CRSA with the reduction in rising time up to 44%, workload up to 35%, settling time up to 26% and chattering error up to 18% of the nominal value.

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39

Jasiński, Ryszard. "Influence of Type of Material on Performance of Hydraulic Components in Thermal Shock Conditions." Solid State Phenomena 183 (December 2011): 95–100. http://dx.doi.org/10.4028/www.scientific.net/ssp.183.95.

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During the start-up of a hydraulic system in low ambient temperatures an incorrect operation may occur. The principles and conditions of safely operating hydraulic driven machines and devices are essential to designers and operators. For this reason the author of this article has conducted a series of tests on hydraulic components and systems in thermal shock conditions (cooled-down components were supplied with hot working medium). In such conditions, the initial parameters of the hydraulic components and systems determine their correct operation. During the start-up of a hydraulic system in thermal shock conditions, elements of hydraulic components warm up in a non-uniform way, due to various material properties and shapes of parts. Differences in clearances between elements and may lead to the faulty performance of hydraulic components and machine break-down. The selection of appropriate materials for various hydraulic component parts should increase machine safety during start-up in thermal shock conditions.

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40

Lyu, Kefeng, Xuelei Sheng, and Xudan Ma. "Thermal-hydraulic Assessment of Seven Wire-wrapped rod Bundle." E3S Web of Conferences 212 (2020): 01009. http://dx.doi.org/10.1051/e3sconf/202021201009.

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Lead bismuth eutectic (LBE) is one of the most potential materials for coolant and spallation target for Accelerator Driven Systems (ADS). Thermal-hydraulic behavior of LBE in fuel assembly is a key issue for development of the systems. To get a deeper understanding on the complex thermal-hydraulic features of wire-wrapped rod bundle cooled by upward LBE, an electrically bundle with 7 rods wrapped with helical wire was developed in KYLIN-II thermal-hydraulic forced circulation loop. The flow resistance, thermal entrance characteristic and heat transfer coefficient were investigated. As for the entrance characteristics, during the full heating length (exceeding 140 times the hydraulic diameter), the thermal field did not reach a fully developed and stable condition which is contrary to the ducted flows. The experimental heat transfer coefficient showed that the hexagonal shell has a great influence on the heat transfer coefficient in rod bundle geometry. For this reason the application of empirical correlation should be kept cautious in rod bundle analysis.

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41

Jasiński, Ryszard. "Influence of Design of Hydraulic Components on their Operation in Low Ambient Temperatures." Key Engineering Materials 490 (September 2011): 106–18. http://dx.doi.org/10.4028/www.scientific.net/kem.490.106.

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In many machines and devices there are hydraulic drives. They should operate well in various weather conditions, also in low ambient temperatures. Some malfunctions may occur during operation of hydraulic system in a so called “thermal shock condition”, which happens when frozen hydraulic component (e.g. hydraulic pump, motor or directional spool valve) is suddenly supplied with hot oil. Transient thermal state emerges in these conditions. Particular elements of component warm up differently. This results in different thermal expansion of components during warm up, which is changing the size of clearance between cooperating elements. Experimental tests of hydraulic components in low ambient temperatures were conducted in the hydraulic laboratory of the Faculty of Mechanical Engineering of Gdansk University of Technology. They concerned: orbital motors, satellite motors, gear pumps, spool valves (also proportional), piston pumps, and hydraulic cylinders. It was proved, that in thermal shock conditions some malfunctions may occur, especially with large temperature differences between oil and component. Based on results of the tests of hydraulic components and systems start-up in low ambient temperatures, one can perform a change in components design, change the type of material of components elements, and even prepare a proper procedure to be followed during start-up of cold hydraulic components and systems. In the article discusses some designs of hydraulic components resistant to thermal shock, and how to prepare components to work in low temperatures, e.g. by providing system with an additional heater to ensure uniform heating of elements in components. Change in design of hydraulic components resistant to thermal shock conditions can be obtained through computer simulation method. Analytic and computer simulation methods can be used by engineers who design machines and devices that work in low ambient temperatures.

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42

ABDALLA, ANISEH AHMED ATEF, JIYANG YU, and YONGWEI YANG. "Thermal-hydraulic analysis of LBE spallation target for accelerator-driven systems." Pramana 80, no. 1 (January 2013): 89–103. http://dx.doi.org/10.1007/s12043-012-0458-3.

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43

LYU, Kefeng, Xuelei SHENG, Xudan MA, and Haitao WANG. "CFD Analysis of Scaled Wire-wrapped rod Bundle Cooled by LBE." E3S Web of Conferences 136 (2019): 01044. http://dx.doi.org/10.1051/e3sconf/201913601044.

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Lead bismuth eutectic (LBE) is one of the most potential materials for coolant for Lead based reactor and Accelerator Driven Systems (ADS). Thermal-hydraulic behaviour of LBE in fuel assembly is a key issue for development of the systems. To get a deeper understanding on the complex thermal-hydraulic features of wire-wrapped rod bundle cooled by upward LBE, CFD calculation based on RANS methodologies were also performed to support the experimental results analysis. The results concluded that LBE has the similar flow resistance characteristics with traditional fluids. Both the Rehme correlation and CFD showed a good agreement with the experimental results. As for the entrance characteristics, during the fully heating length (exceeding 140 times the hydraulic diameter), the thermal field did not reach a fully developed and stable condition which is contrary to the ducted flows. Based on the experimental results and CFD investigation of heat transfer coefficient showed that the hexagonal shell has a great influence on the heat transfer coefficient in rod bundle geometry. For this reason, the application of empirical correlation should be kept cautious in rod bundle analysis.

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44

Jasiński, Ryszard. "Determination of Ability of Hydrotronic Systems to Start in Low Ambient Temperatures." Solid State Phenomena 164 (June 2010): 31–36. http://dx.doi.org/10.4028/www.scientific.net/ssp.164.31.

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During start-up of hydrotronic system (hydraulic system with electric control) in low ambient temperatures a faulty operation may occur. The principles and conditions of safe operation of hydraulically (hydrotronically) driven machines and devices is essential for their designers and operators. For these reasons the author did a series of tests of hydraulic (hydrotronic) components and systems under thermal shock conditions (cooled-down components were supplied with hot working medium). In such conditions starting parameters of the selected hydrotronic components and systems, which secured safety of their operation, were determined. During start-up of a hydrotronic system under thermal shock conditions elements of hydraulic components warm up in a non-uniform way, due to varying material and shape properties. This causes change of clearances between the cooperating elements and may lead to faulty performance of hydraulic components and result in machine break-down. Heat transfer coefficients between oil and swilled element were determined and used for a calculation method developed by the author. The method enables to predict correct or incorrect operation of hydrotronic system.

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45

Ma, Yugao, Jinkun Min, Jin Li, Shichang Liu, Minyun Liu, Xiaotong Shang, Ganglin Yu, Shanfang Huang, Hongxing Yu, and Kan Wang. "Neutronics and thermal-hydraulics coupling analysis in accelerator-driven subcritical system." Progress in Nuclear Energy 122 (April 2020): 103235. http://dx.doi.org/10.1016/j.pnucene.2019.103235.

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46

Samier, Pierre, Atef Onaisi, and Sergio de Gennaro. "A Practical Iterative Scheme for Coupling Geomechanics With Reservoir Simulation." SPE Reservoir Evaluation & Engineering 11, no. 05 (October 1, 2008): 892–901. http://dx.doi.org/10.2118/107077-pa.

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Summary The use of reservoir simulation coupled with geomechanics has been increasing in recent years as its utility in modeling physical phenomena such as compaction, subsidence, induced fracturing, enhancement of natural fractures and/or fault activation, and steam-assisted gravity drainage (SAGD) recovery has become apparent. Among different methods investigated by researchers, the iterative explicit method appears to be the preferred method for field-scale simulation. This method is a loose coupled approach between a reservoir simulator and a geomechanical simulator. At user-defined steps, the fluid pressures are transmitted to the geomechanical tool, which computes the actual stresses and reports the modifications of porosities and permeabilities back to the reservoir simulator. This paper presents a new iterative scheme that allows any reservoir simulator to be coupled with any nonlinear finite-element-method (FEM) package for the stress analysis without any limitation on the functionality of either simulator. The convergence of this new scheme is discussed, and results are presented for three cases described below. The first case is a validation case used by other SPE papers. The second case is a synthetic model of a highly compacting reservoir sensitive to water saturation. The third case is a full-field reservoir model. Introduction The importance of geomechanics in problems such as wellbore stability, hydraulic fracturing, and subsidence is well known. In recent years, there has been growing awareness of the importance of the link between fluid flow and geomechanics in the management of stress-sensitive reservoirs (Chen and Teufel 2001; Gutierrez et al. 1994, 1995; Gutierrez and Lewis 1998; Osorio et al. 1999; Settari and Mourits 1998; Somerville and Smart 2000; Stone et al. 2000; Tran et al. 2002). New needs for coupled simulations appear, such as assessing the integrity of the overburden for heavy-oil recovery using thermal mechanisms (e.g., SAGD technique) or for acid-gas injection. Standard reservoir simulation of compaction drive accounts for nonlinear porosity changes determined from uniaxial-strain tests on cores. In many cases, laboratory-derived compressibility must be adjusted to match the contribution of compaction to total hydrocarbon recovery. Geomechanical effects such as stress arching and nonunique stress path are among the causes of discrepancy between laboratory-derived and field compressibility factors. If compressibility varies linearly with the mean reservoir pressure, then predictive reservoir modeling can be achieved without coupling between stress and flow. However, geomechanical effects are rarely linear, for a number of reasons. These include load variations because of modification of pressure, temperature, and saturation; change of the mechanism of production; and progressive activation of faults, and fractures that affect mechanisms such as stress arching and a nonlinear stress path. Unlike standard compaction-drive simulation, there is no simple linear method to account for the effects of stress on permeability, especially for fractured systems, in which the changes of permeability might be directional, localized, and strongly nonlinear. There are several ways to achieve the coupling between flow and stress (Charlier et al. 2002; Samier et al. 2006; Yale 2002; Chen and Teufel 2000; Koutsabeloulis and Hope 1998; Lewis and Ghafouri 1997; Settari and Walters 1999; Mainguy and Longuemare 2002; Dean et al. 2006; Gutierrez and Lewis 1998; Thomas et al. 2002). The most rigorous coupling is achieved with fully coupled simulators, which not only solve the flow and the mechanical equations simultaneously but also allow for anisotropy and nonlinearity of the rock constitutive model. The feasibility and accuracy of such simulators, as far as complex and large-scale reservoir systems are concerned, have yet to be proved. Partial coupling on the other hand consists of linking a flow simulator with a stress simulator, allowing a good compromise between feasibility and accuracy. A one-way link from flow to stress simulator is often used for subsidence forecasts. However, to solve the compaction-drive problem, one-way coupling is not sufficient. To ensure the compatibility of pore-volume calculations from the flow and the stress simulators, iterations must be performed within each stress-analysis step before proceeding to the next stress step with or without permeability changes.

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47

HAYASHI, Ken-ichi, Mikinori ONO, Kenji KIKUCHI, Noriya TOKUNAGA, Teruaki KITANO, and Hiroyuki OIGAWA. "Thermal-Hydraulic Experiment on Beam Window for Developing the Accelerator-Driven Transmutation System." Transactions of the Atomic Energy Society of Japan 7, no. 1 (2008): 44–57. http://dx.doi.org/10.3327/taesj.j07.002.

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48

Dontsov, E. V. "Propagation regimes of buoyancy-driven hydraulic fractures with solidification." Journal of Fluid Mechanics 797 (May 16, 2016): 1–28. http://dx.doi.org/10.1017/jfm.2016.274.

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This study investigates the propagation of a semi-infinite buoyancy-driven hydraulic fracture in situations when the fluid is able to solidify along the crack walls. Such problems occur when hot magma ascends from a chamber due to buoyancy forces and solidifies by interacting with colder rock. In the model, the solidification rate is calculated assuming a one-dimensional heat transfer problem, in which case it becomes mathematically equivalent to Carter’s leak-off model, which is commonly used to describe the fluid leak-off from a hydraulic fracture into a porous rock formation. In order to construct a mathematical model for a buoyancy-driven hydraulic fracture with solidification, the aforementioned thermal problem is combined with (i) linear plane-strain elasticity to ensure equilibrium of the rock surrounding the fracture, (ii) linear elastic fracture mechanics to determine the fracture propagation, (iii) lubrication theory to capture the viscous fluid flow inside the crack and to account for the effect of buoyancy, and (iv) volume balance of the magma. To address the problem, the governing equations are first rewritten in terms of one integral equation with a non-singular kernel, which significantly simplifies the analysis and the procedure for obtaining a numerical solution. The latter solution is shown to obey a multiscale behaviour near the fracture tip that is fully resolved by the numerical scheme. In order to understand the structure of the solution and to quantify the regimes of propagation (and the associated transitions), a thorough analysis of the problem has been performed. Finally, the developments are applied to investigate the non-steady propagation of a buoyancy-driven fracture that is fed by a constant flux.

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49

Mehendale, S. S., A. M. Jacobi, and R. K. Shah. "Fluid Flow and Heat Transfer at Micro- and Meso-Scales With Application to Heat Exchanger Design." Applied Mechanics Reviews 53, no. 7 (July 1, 2000): 175–93. http://dx.doi.org/10.1115/1.3097347.

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By their very nature, compact heat exchangers allow an efficient use of material, volume, and energy in thermal systems. These benefits have driven heat exchanger design toward higher compactness, and the trend toward ultra-compact designs will continue. Highly compact surfaces can be manufactured using micro-machining and other modern technologies. In this paper, unresolved thermal-hydraulic issues related to ultra-compact designs are discussed, and the status of the technologies required for the production of ultra-compact structured surfaces is summarized. This review article includes 67 references.

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50

Su, D. N., Kang Min Zhong, and X. L. Dai. "Green and Intelligent: Electromechanical-Hydraulic Integrated Clamping Device Based on Thermal Sensitive Material." Key Engineering Materials 392-394 (October 2008): 381–86. http://dx.doi.org/10.4028/www.scientific.net/kem.392-394.381.

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The fluid-driven clamping devices extensively used in the manufacturing industry nowadays are unable to adapt to the development requirements for green manufacturing technology owing to their low energy utilization, severe problems of noise and environment pollution. This article describes a clamping technology sparing the need of hydraulic pump and air compressor. It causes the thermal sensitive material to quickly expand or shrink linearly with the help of semiconductor heating/refrigeration conversion technology; then with the area effect stroke amplifier, the linear extension generated by the material is amplified around 100 times, and is output and passed to the clamping element in a linear motion manner to clamp the workpiece. This clamping device is an intelligent controlled electromechanical-hydraulic integrated system, featuring high energy utilization, extra low noise and fluid leakage etc.

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