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1
Xu, Ziming, Jun Xu, Zhechen Guo, Haitao Wang, Zheng Sun, and Xuesong Mei. "Design and Optimization of a Novel Microchannel Battery Thermal Management System Based on Digital Twin." Energies 15, no. 4 (February 15, 2022): 1421. http://dx.doi.org/10.3390/en15041421.
Повний текст джерелаАнотація:
In order to avoid high-temperature and large rate discharge impact on the performance of battery modules, a microchannel liquid cooling battery thermal management system (BTMS) and BTMS virtual model of the microchannel structure based on digital twin (DT) is proposed. On the basis of accurate virtual simulation model, the computational fluid dynamics (CFD) model and the Gaussian process regression algorithm were combined to drive the optimization process in order to improve the cooling capacity of the system. The results show that the microchannel plates can greatly enhance the cooling capacity of the direct cooling system and effectively improve the uniformity of the coolant. The width of the microchannel plates and the side spacing actually represent the amount of coolant flowing through the inside and outside of the battery module, which significantly impacts the maximum temperature and maximum temperature difference. Increasing the coolant flow can only effectively improve the cooling capacity of the module to a limited extent. Gaussian process regression based on the DT virtual model is more suitable for analyzing the interaction between multiple factors and obtaining global optimization results. After optimization, the maximum temperature and the maximum temperature difference of the system are reduced by 4.02 °C and 5.05 °C, respectively. The proposed structure and method are expected to provide insights into the design and development of battery thermal management systems.
2
Li, Tingxuan, Zhilin Xia, and Xiaochun Fan. "Cooling capacity evaluation of passive radiation cooling materials." Journal of Physics: Conference Series 2200, no. 1 (February 1, 2022): 012021. http://dx.doi.org/10.1088/1742-6596/2200/1/012021.
Повний текст джерелаАнотація:
Abstract passive radiation cooling technology has aroused widespread interest and research enthusiasm because it can cool objects with zero energy consumption, and even cool to below the ambient temperature. At present, when evaluating the cooling performance of radiation cooling materials, in order to reduce the impact of air convection heat transfer and improve the radiation cooling capacity of materials, test samples are usually put into incubators for insulation. In this paper, the finite element method was used to analyze the influence of the size and material of the common used structural incubator on the radiation cooling capacity of the test sample, as well as the influence of the selection of reference ambient temperature. Results show that the selection of incubator structure, material and ambient temperature has a obvious impact on the evaluation results of material radiation cooling capacity, especially when the ambient heat convection coefficient is low. Therefore, for comparing the test results of different research work, a unified incubator design is needed, including structural size and material selection.
3
Трушляков, Євген Іванович, Андрій Миколайович Радченко, Сергій Анатолійович Кантор, Веніамін Сергійович Ткаченко, Сергій Георгійович Фордуй та Ян Зонмін. "ВИЗНАЧЕННЯ ПРОЕКТНОЇ ХОЛОДОПРОДУКТИВНОСТІ СИСТЕМИ КОНДИЦІЮВАННЯ ПОВІТРЯ В КОНКРЕТНИХ КЛІМАТИЧНИХ УМОВАХ І РІЗНИМИ МЕТОДАМИ". Aerospace technic and technology, № 6 (24 грудня 2019): 15–19. http://dx.doi.org/10.32620/aktt.2019.6.03.
Повний текст джерелаАнотація:
The cold output for the heat-moisture treatment of ambient air in air conditioning systems depends on its parameters (temperature and relative humidity), which vary significantly during operation. To determine the installed (design) cooling capacity of air conditioning system chillers, it is proposed to use a reduction in fuel consumption of a power plant or cooling capacity generation following its current conditioning spending over a certain period, since both of these indicators characterize the efficiency of using the installed cooling capacities of the air conditioning system. To extend the results of the investigation to a wide range of air conditioning units, two methods were used to determine the design cooling capacity (refrigerating capacity): by the maximum annual value and by the maximum growth rate of the efficiency indicator. The first method allows choosing the design cooling capacity, which provides a maximum annual reduction in the specific fuel consumption due to air cooling or maximum cooling capacity generation, which is necessary for air cooling following current climatic conditions. The second method allows determining the minimum design (installed) cooling capacity of chillers, which provides the maximum rate of reduction in fuel consumption by the power plant and the increment in the annual cooling capacity generation following the installed cooling capacity of chillers. The efficiency of air conditioning systems was analyzed for different climatic conditions: a temperate climate using the example of Voznesensk city (Ukraine) and the subtropical climate of Nanjing city (China). It is shown that the design cooling capacity values calculated by both indicators of its use efficiency are the same for the same climatic conditions. Wherein, if to determine the design cooling capacity by both methods - by the maximum annual value and the maximum rate of growth of the indicator, its values turned out to be quite close for tropical climatic conditions and somewhat different for a temperate climate.
4
Kula, Sinan. "Design Studies of Two Stage Cooling Loop for New Generation Vehicles." Academic Perspective Procedia 3, no. 1 (October 25, 2020): 550–59. http://dx.doi.org/10.33793/acperpro.03.01.104.
Повний текст джерелаАнотація:
In this article, the design and integration of an intelligent refrigeration system that increases air conditioning and engine efficiency, reduces fuel consumption and emission levels in vehicles manufactured today will be examined. This design will include a two-stage cooling system. Two-stage cooling unit consist; high temperature radiator and low temperature radiator. The engine coolant will be cooled in the high temperature radiator. In the low temperature radiator, coolant of water cooled air charger and air conditioning condenser will be cooled. It is aimed to increase the engine efficiency by cooling more efficiently, thanks to the heat carrying capacity of the water which is high compared to air. With this project, it is aimed to cool the heated air after the turbocharging and air conditioning gas in the vehicle with water instead of air.
5
Seyed Salehi, Seyed Shahabaldin, Andrea Ferrantelli, Hans Kristjan Aljas, Jarek Kurnitski, and Martin Thalfeldt. "Impact of internal heat gain profiles on the design cooling capacity of landscaped offices." E3S Web of Conferences 246 (2021): 07003. http://dx.doi.org/10.1051/e3sconf/202124607003.
Повний текст джерелаАнотація:
Using passive methods in façade design for controlling heating and cooling needs is an important prerequisite for constructing cost-effective nearly zero-energy buildings. Optimal control of solar heat gains reduces the cooling demand and the size of the active cooling systems. However, applying such methods increases the impact of internal heat gains on the heat balance of the buildings, and accordingly also the dimensions of cooling systems. Therefore, a good model of internal heat gains is needed for a reliable and optimal sizing of the cooling sources. This paper aims to bring understanding to developing internal heat gains models for sizing the cooling systems. For this purpose, several weekly internal heat gain profiles were selected from a large set of tenant-based electricity use measured in 4 office buildings in Tallinn. The selection was based on maximum daily or weekly peak loads of an office space per floor area. The selected profiles and the schedule of EN 16798-1 were used to dimension ideal coolers in the zones of a generic floor model with landscaped offices developed in IDA-ICE 4.8. The model had variable window sizes and thermal mass of the building materials. Finally, the internal heat gains models resulting in the largest cooling capacity were identified. We found that utilizing thermal mass can reduce the cooling system size by up to 7% on average and the models with big windows and light structure need the largest cooling systems. The cooling loads obtained with the profile of EN 16798-1 did not significantly differ from the average of other profiles’ results. This paper focused mainly on the zonal dimensioning of cooling systems, therefore a more in-depth analysis of the different occupancy patterns as well as developing models for dimensioning the cooling system at the building level, is needed.
6
Song, Jiangnan, Ying Huang, Yi Liu, Zongpeng Ma, Lunjun Chen, Taike Li, and Xiang Zhang. "Numerical Investigation and Optimization of Cooling Flow Field Design for Proton Exchange Membrane Fuel Cell." Energies 15, no. 7 (April 2, 2022): 2609. http://dx.doi.org/10.3390/en15072609.
Повний текст джерелаАнотація:
High temperatures and non-uniform temperatures both have a negative bearing on the performance of proton exchange membrane fuel cells. The temperature of proton exchange membrane fuel cells can be lowered by reasonably distributed cooling channels. The flow field distribution of five different cooling plates is designed, and the temperature uniformity, pressure drop and velocity of each cooling flow field are analyzed by computational fluid dynamics technology. The results show that while the pressure drop is high, the flow channel distribution of a multi-spiral flow field and honeycomb structure flow field contribute more to improving the temperature uniformity. As the coolant is blocked by the uniform plate, it is found that although the flow field channel with a uniform plate has poor performance in terms of temperature uniformity, its heat dissipation capacity is still better than that of the traditional serpentine flow field. The multi-spiral flow field has the strongest ability to maintain the temperature stability in the cooling plate when the heat flux increases. The increase in Reynolds number, although increasing the pressure drop, can reduce the maximum temperature and temperature difference of the flow field, ameliorate the temperature uniformity and improve the heat transfer capacity of the cooling plate.
7
Трушляков, Євген Іванович, Андрій Миколайович Радченко, Микола Іванович Радченко, Сергій Анатолійович Кантор та Веніамін Сергійович Ткаченко. "ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ КОНДИЦІЮВАННЯ ЗОВНІШНЬОГО ПОВІТРЯ СИСТЕМИ КОМБІНОВАНОГО ТИПУ". Aerospace technic and technology, № 4 (31 серпня 2019): 9–14. http://dx.doi.org/10.32620/aktt.2019.4.02.
Повний текст джерелаАнотація:
One of the most attractive reserves of enhancing the energetic efficiency of air conditioning systems is to provide the operation of refrigeration compressors in nominal or close to nominal modes by choosing rational design cooling loads (cooling capacities) and their distribution according to a cooling load behaviour within the overall design (installed) cooling load band to match current changeable climatic conditions and provide close to maximum annual cooling capacity generation according to cooling duties. The direction of increasing the efficiency of outdoor air conditioning in combined central-local type systems by rationally distributing the heat load - cooling capacity of the central air conditioner into zones of variable heat load in accordance with current climatic conditions and its relatively stable value, i.e. cooling capacity required for further air cooling at the entrance to the indoor recirculation air conditioning system is justified. By comparing the values of the excessive production of cold and its deficit within every 3 days for a rational design heat load of the air conditioning system (cooling capacity of the installed refrigeration machine), which provides close to maximum annual production of cold, and the corresponding values of the excess and deficit of cooling capacity in accordance with current climatic conditions during July substantiated the feasibility of accumulating the excess of cooling capacity of a central air conditioner at low current loads and its use for covering cooling deficit at elevated heat loads through pre-cooling the outdoor air. It is developed a scheme of a combined central-local air conditioning system, which includes the subsystems for the outdoor air conditioning in a central air conditioner and the local indoor recirculated air conditioning.
8
Lakovic, Mirjana, Milos Banjac, Slobodan Lakovic, and Milica Jovic. "Industrial cooling tower design and operation in the moderate-continental climate conditions." Thermal Science 20, suppl. 5 (2016): 1203–14. http://dx.doi.org/10.2298/tsci16s5203l.
Повний текст джерелаАнотація:
A large number of producers offer a wide choice of various types of industrial cooling towers. Usually, a proper choice of pre-fabricated cooling tower satisfies end-user needs. However, if there are specific end-user requirements, it is necessary to design cooling tower according to those requirements. For the adhesive factory located in southern region of Serbia, 350 kW mechanical draught wet cooling tower was designed and built. Dimensioning of the cooling tower was done according to parameters of the ambient air, higher than the standard recommendations given in the literature. In this paper, the reasons for deviation from recommendations are given. The analysis of the cooling tower operation based on real meteorological parameters for 2015 is also shown in this paper. According to this analysis, cooling tower provides required water temperature in any season, and gives opportunity for energy savings in winter, with opportunity for heat capacity enlargement if production capacity is raised as it is planned in the factory.
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Радченко, Андрій Миколайович, Ян Зонмін, Микола Іванович Радченко, Сергій Анатолійович Кантор, Богдан Сергійович Портной та Юрій Георгійович Щербак. "ВИЗНАЧЕННЯ ВСТАНОВЛЕНОЇ ХОЛОДОПРОДУКТИВНІСТІ СИСТЕМИ ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ ГАЗОТУРБІННОЇ УСТАНОВКИ ЗА ПОТОЧНИМ ТЕПЛОВИМ НАВАНТАЖЕННЯМ". Aerospace technic and technology, № 2 (22 квітня 2019): 56–60. http://dx.doi.org/10.32620/aktt.2019.2.07.
Повний текст джерелаАнотація:
Significant fluctuations of the current temperature and relative humidity of the ambient air lead to significant changes in the thermal load on the cooling system at the inlet of gas turbine units (GTU), which acutely raises the problem of choosing their installed (design) thermal load. Calculations of ambient air cooling processes were carried out for different climatic conditions, for example, southern Ukraine (Mykolaiv) and Central China (Beijing). It is analyzed two methods of determination of the installed (design) cooling capacity of the ambient air cooling system at the GTU inlet according to the maximum current reduction of fuel consumption and according to the maximum rate (increase) of annual reduction of fuel consumption following to increasing of the installed cooling capacity, calculated by summarizing the current values of fuel consumption reduction. It is shown that the values of the installed cooling capacity of the air cooling system at the GTU inlet, determined by both methods, are close enough but differ significantly for different climatic conditions. The advantage of the method of calculating the installed cooling capacity of the air cooling system at the GTU inlet according to the maximum rate of annual reduction in fuel consumption is the possibility of a more precise definition of it due to the absence of significant fluctuations in the annual reduction in fuel consumption, calculated by summarizing the current values of fuel consumption reduction. Since the maximum reduction in fuel consumption per year is achieved with some decrease in the rate of its increment at high values of the design cooling capacity, required in the hottest hours in the summer and excessive in somewhat cool periods (at night and in the morning even in the summer), the installed cooling capacity, determined according to the maximum rate of the reduction of fuel consumption, will be insufficient in times of increased thermal loads above their design value. In such cases, the elimination of the deficit in cooling capacity is possible by using an excess of cold accumulated during reduced thermal loads
10
Радченко, Андрій Миколайович. "МЕТОД ВИЗНАЧЕННЯ ХОЛОДОПРОДУКТИВНОСТІ ТЕРМОТРАНСФОРМАТОРА ЗА МАКСИМАЛЬНИМ ТЕМПОМ ПРИРОЩЕННЯ ТЕРМОЧАСОВОГО ПОТЕНЦІАЛУ ОХОЛОДЖЕННЯ ПОВІТРЯ". Aerospace technic and technology, № 4 (14 жовтня 2018): 53–57. http://dx.doi.org/10.32620/aktt.2018.4.07.
Повний текст джерелаАнотація:
It is proved a possibility of using the thermohour cooling potential method, developed by the author, for defining the installed (design) refrigeration capacity of term transformer (refrigeration machine), providing a maximum rate of thermo-hour cooling potential increasing according to the current climatic conditions for a definite period of operation.It is proposed to define the effect, gained due to cooling air, in particular at the inlet of GTU, depends on duration and depth of cooling, by thermohour potential ÕS,°С·h, as air temperature decrease Δta multiplied by duration τ of GTU operation at decreased temperature: ÕS = ∑(Δta ∙°τ), which to some extent characterizes heat load on the cooling system.It is shown that taking into consideration a different rate of annual thermohour cooling potential arising with increasing the installed refrigeration capacity of term transformer, caused by changing the heat load according to current climatic conditions during a year, it is necessary to choose such design heat load on the air cooling system (refrigeration capacity of term transformer) that provides a maximum value of annual thermohour cooling potential or close it with relatively high rates of its increasing. To define the installed refrigeration capacity, providing a maximum rate of annual thermohour cooling potential increasing, it is analyzed the dependence of annual thermohour cooling potential related to the installed refrigeration capacity of term transformer, from the installed refrigeration capacity of term transformer. As a result of the investigation, it is proposed the method of defining the design heat load (installed refrigeration capacity) of term transformer with maximum rates of increasing thermohour cooling potential, as a further development of methodology of rational designing of them transformers for combustion engine inlet air cooling on the base of thermohour potential, developed by author
11
Zamhuri, Muhammad Ikhwan, Haslenda Hashim, and Ho Wai Shin. "Optimal Design of Integrated Chiller Capacity with Ice Thermal Storage for Commercial Buildings through Cooling System Cascade Analysis." International Journal of Innovative Technology and Exploring Engineering 10, no. 2 (December 10, 2020): 165–75. http://dx.doi.org/10.35940/ijitee.b8301.1210220.
Повний текст джерелаАнотація:
Chilled water air conditioning system is used to supply cooling systems in large capacity for industrial processes and commercial buildings. Air conditioners contribute more than 60 percent of electricity consumption in buildings. District Cooling System (DCS) technology comprises a central chiller plant which provides advantage compared to local air conditioning system. It has higher efficiency, uses less power in system operation, allows more usable space in buildings, and can be operated with minimum manpower while handling same amount of cooling load. The integration of a chiller with ice thermal storage (ITS) offers more operational flexibility while reducing space cooling expenses. This paper presents a systematic framework for design and operation of District Cooling Plant (DCP) comprising an integrated chiller and ice thermal storage system. The Cooling System Cascade Analysis (COSCA) based on pinch analysis is constructed to determine the chiller optimal size and ice thermal storage capacity. The District Cooling System configuration for this study comprises a cooling tower, chiller (centrifugal, variable centrifugal, glycol) and ice thermal storage system. The application of this technique to fulfil 66,284 refrigerant tonne hour (RTH) cooling load demand from commercial buildings reveals the optimal capacity of the chiller is 3068.91 refrigerant tonne (RT), ice tank rating at 989 refrigerant tonne (RT) and ice tank capacity is 9892.75 refrigerant tonne hour (RTH).
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KAWANO, Koichiro, Debasish BISWAS, and Masaru ISHIZUKA. "Cooling Design of Large Capacity Gas Insulated Transformer Using Flow Visualization." Journal of the Visualization Society of Japan 19, no. 73 (1999): 111–16. http://dx.doi.org/10.3154/jvs.19.73_111.
Повний текст джерела
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Radzai, Mohammad Hakim Mohd, Chong Tak Yaw, Chin Wai Lim, Siaw Paw Koh, and Nur Amirani Ahmad. "Numerical Analysis on the Performance of a Radiant Cooling Panel with Serpentine-Based Design." Energies 14, no. 16 (August 4, 2021): 4744. http://dx.doi.org/10.3390/en14164744.
Повний текст джерелаАнотація:
Radiant cooling systems (RCS) are gaining acceptance as a heating, ventilation, and air conditioning (HVAC) solution for achieving adequate thermal comfort and maintaining acceptable indoor air quality inside buildings. RCS are well known for their energy-saving potential; however, serious condensation problem hinders the growth of this technology. In order to prevent the risk of condensation, the supply water temperature is kept higher than the dew point temperature of the air inside the room. The full potential of the cooling power of a radiant cooling panel is limited. Therefore, this article is on maximizing the cooling capacity of a radiant cooling panel, in terms of flow configuration. Radiant cooling panels (RCP) with different chilled water pipe configurations are designed and compared, side by side with the conventional serpentine flow configuration. The cooling performance of the radiant cooling panels is evaluated by using computational fluid dynamics (CFD) with Ansys Fluent software (Ansys 2020 R2, PA, USA). Under similar flow and operating conditions, the common serpentine flow configuration exhibits the least effective cooling performance, with the highest pressure drop across the pipe. It is concluded that the proposed designs have the potential of improving the overall efficiency of RCP in terms of temperature distribution, cooling capacity, and pressure drop.
14
Khosala, Yudha. "Thermal Calculation for Water Cooling Tower To Cool Compressor ATLAS COPCO GA 250 FF." ACMIT Proceedings 3, no. 1 (March 18, 2019): 193–200. http://dx.doi.org/10.33555/acmit.v3i1.44.
Повний текст джерелаАнотація:
The aim of this paper is to choose the correct capacity of Thermal Calculation for Water Cooling Tower to Cool Compressor ATLAS COPCO GA 250 FF since a cooling tower is considered as an essential component for a compressor in an oil and gas pipe manufacture plant. Cooling tower is an equipment device commonly used to dissipate heat from air conditioning, water-cooled refrigeration, power generation units, and industrial process. In this paper, we use a induced draft counter flow tower for the design of cooling tower which based on Merkel’s method. The tower characteristic is determined by Merkel’s method. A simple algebraic formula is used to calculate the optimum water and air flow rate. This paper calculate the cooling tower characteristic, air flow required, efficiency, effectiveness, and cooling capacity of cooling tower need to cool the compressor compare with the availability cooling tower product in the market. In this paper, we will design based on calculation thermal capacity which lead to decentralizing the cooling tower to reach better energy efficiency of the plant.
15
Радченко, Андрій Миколайович, Богдан Сергійович Портной, Сергій Анатолійович Кантор, Олександр Ігорович Прядко та Іван Володимирович Калініченко. "ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ ГТД ХОЛОДИЛЬНИМИ МАШИНАМИ ШЛЯХОМ АКУМУЛЯЦІЇ ХОЛОДУ". Aerospace technic and technology, № 4 (28 серпня 2020): 22–27. http://dx.doi.org/10.32620/aktt.2020.4.03.
Повний текст джерелаАнотація:
The efficiency of air cooling at the inlet of gas turbine engines by exhaust heat conversion chiller, which transforms the GTE exhaust gases heat into cold, under variable climatic operating conditions, has been investigated. Considered is the use of a combined absorption-ejector exhaust heat conversion chiller with a step-by-step principle of air cooling at the gas turbine engines inlet: preliminary down to 15°C – by an absorption lithium-bromide chiller (ACh), which is used as a high-temperature air cooling stage, and further cooling down to 10°C – by a refrigerant ejector chiller (ECh) as a low-temperature cooling stage. Reserves have been identified for reducing the design (installed) refrigeration capacity of chillers by accumulating excess cold at reduced current heat loads with its use at increased heat loads. In this case, the design (installed) refrigeration capacity of chillers was determined by two methods: the first – based on the close to the maximum reduction in annual fuel consumption, the second – according to the maximum rate of increase in the reduction in annual fuel consumption. A scheme of the air cooling system at the gas turbine engines inlet using the refrigeration capacity reserve of the ACh, which provides preliminary cooling of the ambient air at the gas turbine engines inlet, in the booster stage, using the ACh accumulated excess refrigeration capacity has been proposed. The ACh excess refrigerating capacity, which is formed at decreased heat loads on the air coolers at the gas turbine engines inlet, is accumulated in the cold accumulator and is used at increased heat loads. The simulation results show the advisability of using the air cooling system at the gas turbine engine inlet with using the ACh accumulated excess refrigeration capacity, which allows reducing the ACh design (installed) refrigeration capacity by approximately 40%.
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Woodard, J. K., and G. E. Johnson. "Optimal Design of Cooling Fans for Industrial Electric Motors." Journal of Mechanisms, Transmissions, and Automation in Design 108, no. 2 (June 1, 1986): 224–25. http://dx.doi.org/10.1115/1.3260806.
Повний текст джерелаАнотація:
Various industrial electric motors use a combination of internal and external fans to remove internally generated heat. In recent years as the electrical efficiency of motors has improved, the power drawn by the cooling fans has become a large percentage of the total motor losses. This paper presents an optimization approach to the selection of the cooling fan dimensions. The design objective is to obtain minimum power input to the fans while maintaining adequate cooling capacity. To illustrate the method, the cooling fan design for a 30 hp, 3600 rpm, a-c motor is considered. The optimal fan dimensions result in a 70 percent reduction in fan power.
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Yan, Quan Ying, Ran Huo, and Li Li Jin. "Research on Heat-Transfer Process of the Radiant Ceiling Cooling System." Advanced Materials Research 512-515 (May 2012): 2171–74. http://dx.doi.org/10.4028/www.scientific.net/amr.512-515.2171.
Повний текст джерелаАнотація:
Physical and numerical models of the radiant ceiling cooling system were built and numerically simulated. The results showed that the lower the temperature of cooling water is, the lower surface temperature the ceiling has, and the bigger the cooling capacity is. The bigger the depth of tubes is, the higher the surface temperature and the smaller the cooling capacity. The differences are not evident. The bigger the distance of tubes is, the bigger the surface temperature is and the smaller the cooling capacity is. The diameter of tubes has a few influences on the surface temperature and the cooling capacity. Results in this paper can provide basis and guide for the design of the project, the selection of parameters and the feasibility of the system.
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Raja, V. Boopathi, and V. Shanmugam. "Design and Fabrication of Single Effect Absorption Cooling System of 5.25kW Cooling Capacity for Domestic Use ." Applied Mechanics and Materials 592-594 (July 2014): 1864–68. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.1864.
Повний текст джерелаАнотація:
The aim of this work is to design and fabricate solar assisted single effect absorption cooling system of 5.25 kW cooling capacity to cool a room having floor area of 15m2. The design of the major components of the cooling system like generator, condenser, evaporator, absorber and solution heat exchanger are described in this paper.
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Wardika, Wardika, Aa Setiawan, and Sandi Rifqi Ridwansyah. "Freeze Dryer Machine Design for Mango Fruit Storage." Logic : Jurnal Rancang Bangun dan Teknologi 22, no. 1 (March 30, 2022): 62–69. http://dx.doi.org/10.31940/logic.v22i1.62-69.
Повний текст джерелаАнотація:
The purpose of the research on the design of this tool is to determine the cooling load on the freeze dryer and to determine the time it takes to reach a temperature of -20°C. This tool uses a vapor compression cooling system and a vacuum process means that this tool cools the storage space with air in the dry cabin. The research method is to determine the volume of the cabin to determine the capacity of the freeze dryer and determine the cooling load by calculating the product load and then calculating the heat load through the walls and other loads that generate heat. for a freeze dryer machine with a capacity of 1.8 PK. From testing the tool for 10 minutes once for 6 hours, the results of the system performance at the evaporator temperature -24.64°C and product temperature -16.2°C, COPCarnot performance of 3.77, and COPAktual of 2.87 with an efficiency of 76%, This is in line with the performance values in the COPCarnot design of 3.8 and COPActual of 3.30 with an efficiency of 87%.
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Yan, Chengchu, Qi Cheng, and Hao Cai. "Life-Cycle Optimization of a Chiller Plant with Quantified Analysis of Uncertainty and Reliability in Commercial Buildings." Applied Sciences 9, no. 8 (April 14, 2019): 1548. http://dx.doi.org/10.3390/app9081548.
Повний текст джерелаАнотація:
Conventional and most optimal design methods for chiller plants often address the annual cooling load distribution of buildings and their peak cooling loads based on typical meteorological year (TMY) data, while the peak cooling load only appears a few times during the life-cycle and the sized chiller plant usually operates within its low efficient region. In this paper, a robust optimal design method based on life-cycle total cost was employed to optimize the design of a chiller plant with quantified analysis of uncertainty and reliability. By using the proposed design method, the optimized chiller plant can operate at its highly efficient region under various cooling load conditions, and provide sufficient cooling capacity even alongside some equipment/systems with failures. The minimum life-cycle total cost, which consists of the capital cost, operation, and availability-risk cost, can be achieved through optimizing the total cooling capacity and the numbers/sizes of chillers. A case study was conducted to illustrate the detailed implementation process of the proposed method. The performance of this design method was evaluated by comparing with that of other design methods.
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Saravanan, N., R. Rathnasamy, and V. Ananchasivan. "Design and Analysis of Cooling Cabinet for Vaccine Storage." Advanced Materials Research 984-985 (July 2014): 1180–83. http://dx.doi.org/10.4028/www.scientific.net/amr.984-985.1180.
Повний текст джерелаАнотація:
Solar powered adsorption refrigeration system is renewable source in the future energy demands and more useful for off-grid area. In this paper a mathematical model was developed to investigate the performance of a cooling cabinet of a activated carbon-ammonia adsorption refrigeration system, and a new effective method about the refrigeration studies. A brief thermodynamic study of the cooling cabinet is carried out and the effect of operating parameters such as temperature, pressure, cooling effect of the system is numerically analyzed. The impact of solar intensity on performance of the system is significant. The cooling cabinet model is completely analysied for varies capacity and it is able to calculate the cooling cabinet coil length .The designed mathematical model is analyzed by the use of coolpack software and the results are compared with ansys software. It is observed that the system operate more efficient while maximum solar intensity and the cooling effect. Key words: Solar, Adsorption Refrigeration, Mathematical model, Analysis, Solar intensity.
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Трушляков, Євген Іванович, Андрій Миколайович Радченко, Сергій Георгійович Фордуй, Анатолій Анатолійович Зубарєв, Сергій Анатолійович Кантор та Веніамін Сергійович Ткаченко. "АНАЛІЗ ЕКОЛОГІЧНОЇ ЕФЕКТИВНОСТІ СИСТЕМ КОНДИЦІЮВАННЯ ПОВІТРЯ КОМБІНОВАНОГО ТИПУ". Aerospace technic and technology, № 5 (22 жовтня 2019): 24–29. http://dx.doi.org/10.32620/aktt.2019.5.03.
Повний текст джерелаАнотація:
Since the supply air conditioning systems operation effect depends on the cooling duration and depth, it is quite justified to estimate it by the value of the specific annual cold production, which is the product of the necessary cooling capacity for cooling the air to the target temperature multiplied by duration of operation at a given cooling capacity and, thus, considers current climatic conditions. Obviously, the realization of the cooling potential (air conditioning) of the ambient air depends on the installed (design) cooling capacity of the air conditioning units, which, in turn, must considering fluctuations in thermal loads by the current variable thermal and humidity parameters of the ambient air. With an increase in the temperature of the ambient air, fuel consumption for the production of a unit capacity (mechanical/electrical energy) increases, and, accordingly, the more harmful substances are removed to the atmosphere with exhaust gases. To reduce the negative impact of unproductive fuel consumption during the operation of air conditioning systems at elevated ambient temperatures, resort to various methods for determining the installed cooling capacity of the installation, to reduce it. In the work, the ecological efficiency of air cooling is studied considering the climatic operating conditions for the Kyiv city that are variable during the year. The annual reduction in emissions of carbon dioxide CO2 and nitric oxide NOX was chosen as indicators for assessing the environmental effect of air cooling. It has been shown that when choosing the installed cooling capacity, by the method of ensuring the maximum growth rate of the annual cold production considering the increase in the installed cooling capacity of the chiller, there is a greater reduction in specific fuel consumption compared to the method of choosing the maximum annual cold production, respectively, and harmful emissions. When comparing the methods for choosing the design cooling capacity, air cooling to 15 °C provides a reduction in carbon dioxide CO2 emissions of more than 34 t for 2017 for the climatic conditions of Kiev, in favor of the method of ensuring the maximum growth rate of annual cold production, and nitric oxide NOX – about 5,8 t.
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Bsebsu, F. M., and G. Bede. "Thermal hydraulic analysis and design of the WWR-M2 nuclear research reactor – power upgrading." Kerntechnik 67, no. 2-3 (April 1, 2002): 102–10. http://dx.doi.org/10.1515/kern-2002-0044.
Повний текст джерелаАнотація:
Abstract This paper presents the outline of the core thermal hydraulic design and analysis (Operational Safety Analysis) of the Budapest nuclear research reactor (WWR-M2 type), which is a tank-type, light water-cooled nuclear research reactor with 36% enriched uranium coaxial annuli fuel. The research reactor is currently upgraded to 10 MWth of thermal power, while the cooling capacity of the reactor was designed and constructed for 20 MWth. This reserve in the cooling capacity serves redundancy today but can be used for future upgrading too. The core thermal hydraulic design was, therefore, done for the normal operation conditions so that fuel elements have enough safety margins both against nucleate boiling anywhere in the reactor core. Thermal hydraulic performance was studied. It is shown that the 36% enriched UAlx-Al fuel elements in WWR-SM fuel coolant channel do not allow to force up the reactor power to 20 MWth. The study was carried out for an equilibrium core, with compact load (223 fuel assemblies) under normal operation conditions only (steady state condition).
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Qin, Jiang, Silong Zhang, Wen Bao, Yan Juan Duan, Weixing Zhou, and Daren Yu. "Off-Design Condition Cooling Capacity Analysis of Recooling Cycle for a Scramjet." Journal of Propulsion and Power 28, no. 6 (November 2012): 1285–92. http://dx.doi.org/10.2514/1.b34455.
Повний текст джерела
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Raja, V. Boopathi, and V. Shanmugam. "Experimental Analysis of Newly Designed Solar Assisted Single Effect Absorption Cooling System of 5.25 kW Cooling Capacity for Domestic Use." Applied Mechanics and Materials 787 (August 2015): 32–36. http://dx.doi.org/10.4028/www.scientific.net/amm.787.32.
Повний текст джерелаАнотація:
Many research studies have been carried out to develop small capacity absorption cooling systems as an alternative to conventional vapour compression refrigeration (VCR) systems with respect to performance and economic aspects. The aim of this work is to design a solar assisted single effect absorption cooling system of 5.25 kW cooling capacity to cool a room having floor area of 15 m2. Based on the design, an experimental setup is constructed and operated by supplying heat to the generator using solar energy. The performance analysis of the cooling system is carried out by measuring the various operational parameters. The minimum cooling temperature of 16°C is observed in the evaporator and maximum COP of 0.9 is obtained when the hot water storage tank reaches 90°C. As per this new design, the operational cost is minimized and the COP obtained is slightly higher when compared to that of earlier similar works.
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Kercher, D. M. "A Film-Cooling CFD Bibliography: 1971–1996." International Journal of Rotating Machinery 4, no. 1 (1998): 61–72. http://dx.doi.org/10.1155/s1023621x98000062.
Повний текст джерелаАнотація:
After more than 25 years of three-dimensional film cooling experimental investigations, analytical correlations and modeling, film cooling utilizing computational fluid dynamics has emerged from a similar development-applications growth process into a near-attainable heat transfer engineering tool. Analytical applications include high temperature subsonic to hypersonic flow with complex wall-geometry coolant injection film performance analysis techniques spanning usage from gas turbines to rocket engines to scramjets. In recent years there has been significant development in increased computer power and modeling capacity, increasingly more complex and successful Navier-Stokes turbulence modeling techniques, innovative labor-saving meshing techniques, and more successful validation of experimental results. These combined innovations have continued to transition computational film cooling technology from the academic, government and commercial research and development environment to the industrial design-analysis environment. This bibliography is an openliterature reference resource whose papers collectively describe the continual emerging of numerical film cooling as a viable design tool for high temperature components.
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Gao, Hong Tao, Rui Wang, and Ling Deng. "Experimental Research on Effects of Diffuser and Mixing Chamber on Liquid-Gas Ejector Driven by Aqueous LiBr Solution." Advanced Materials Research 512-515 (May 2012): 2226–30. http://dx.doi.org/10.4028/www.scientific.net/amr.512-515.2226.
Повний текст джерелаАнотація:
From the standpoint of offering reference for its optimal design, liquid-gas ejector is applied to absorption refrigerator in order to improve mass transfer efficiency. The experimental performance of ejector driven by aqueous LiBr solution was investigated. The experimental results indicate that the diffuser with larger diameter of throat could improve the system cooling capacity while reducing the volume of absorber; the larger diameter of the mixing chamber could improve the cooling capacity, but the extent of improvement is little and the required absorber volume per kW of cooling capacity greatly is increased.
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Трушляков, Євген Іванович, Андрій Миколайович Радченко, Микола Іванович Радченко, Сергій Георгійович Фордуй, Сергій Анатолійович Кантор та Богдан Сергійович Портной. "МЕТОДОЛОГІЧНІ ПІДХОДИ ДО ВИЗНАЧЕННЯ ХОЛОДОПРОДУКТИВНОСТІ СИСТЕМ КОНДИЦІЮВАННЯ ПОВІТРЯ ЗА ЗМІННИХ КЛІМАТИЧНИХ УМОВ". Aerospace technic and technology, № 7 (31 серпня 2019): 71–75. http://dx.doi.org/10.32620/aktt.2019.7.09.
Повний текст джерелаАнотація:
One of the most attractive reserves for improving the energy efficiency of air conditioning systems is to ensure the operation of refrigeration compressors in nominal or close to nominal modes by selecting a rational design heat load and distributing it within its design value according to the behavior of the current heat load under variable current climatic conditions to provide the maximum or close to maximum annual cooling capacity generation according to cooling duties of air conditioning. In the general case, the overall range of current thermal loads of any air conditioning system includes a range of unstable loads associated with the precooling of ambient air with significant fluctuations in cooling capacity according with current climatic conditions, and a relatively stable range of cooling capacity consumed to further reduce air temperature from a certain threshold temperature to the final outlet temperature. It is quite obvious that a stable range of heat load can be ensured within operating a conventional compressor in a mode close to the nominal mode while precooling the ambient air with significant fluctuations in heat load requires regulation of the cooling capacity through the use of a variable speed compressor. Thus, in response of the behavior of the change in current heat loads, any air conditioning system, whether the central air-conditioning system with its heat procession in a central air conditioner, or a combination thereof with a local recirculation system of indoor air, essentially consists of two subsystems: pre-cooling the ambient air and then cooling it to the set point temperature. The proposed method of distribution of design heat load depending on the behavior of the current heat load is useful for the rational design of central air conditioning systems and their combined versions with the local air conditioning system.
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Трушляков, Євген Іванович, Андрій Миколайович Радченко, Микола Іванович Радченко, Ян Зонмін, Анатолій Анатолійович Зубарєв та Веніамін Сергійович Ткаченко. "ХОЛОДОПРОДУКТИВНІСТЬ СИСТЕМИ КОНДИЦІЮВАННЯ ЗОВНІШНЬОГО ПОВІТРЯ ЗА ПОТОЧНИМ ТЕПЛОВИМ НАВАНТАЖЕННЯМ". Aerospace technic and technology, № 2 (22 квітня 2019): 51–55. http://dx.doi.org/10.32620/aktt.2019.2.06.
Повний текст джерелаАнотація:
The efficiency of the outdoor air conditioning systems application depends on how full the installed cooling capacity is applied, that is, with a more complete load and for as long as the possible yearly duration in actual climatic conditions. The production of cold is taken as a criteria of a quantitative evaluation of the efficiency of applying the cooling capacity of air conditioning systems – the amount of cold produced in accordance with its current demand for air conditioning, which in turn depends on the current consumption of cooling capacity and its duration and equals to their multiplication. It is obvious that the maximum value of the current amount of cold produced/consumed indicates an effective application of the installed cooling capacity. However, since the current demands of cooling capacity and their duration, that is, the amount of cold produced/consumed, depending on the changing current climatic conditions, they are characterized by significant fluctuations, which makes it difficult to choose the installed cooling capacity of the air conditioning system. Obviously, if we determine the amount of cold produced/consumed by its current values and summarized during the year, it is possible to significantly simplify the choice of the installed cooling capacity. At the same time, the current amount of cold produced/consumed causes a change in the rate of increment of the annual cold production with a change in the installed cooling capacity, and the maximum rate corresponds to the installed cooling capacity, which provides its efficient use. Proceeding from a different rate of increment of annual cold production with an increase in the installed cooling capacity of the air conditioning system due to a change in heat load in accordance with current climatic conditions during the year, the value of design heat load on the air conditioning system (installed cooling capacity) that provides maximum or close to it the rate of increment of the annual production of cold, and hence the maximum efficient use of installed cooling capacity is chosen
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Mullisen, R. S. "Thermal Engineering Design Project: Disk Brake Cooling Simulation." International Journal of Mechanical Engineering Education 25, no. 4 (October 1997): 299–305. http://dx.doi.org/10.1177/030641909702500406.
Повний текст джерелаАнотація:
A thermal engineering design project involving simulated cooling of vented and nonvented disk brakes is described. A heated copper tube was rotated in a manner that replicated the motion of a single vented passageway inside a disk brake rotor. The class assignment required design and construction of equipment, and data reduction using the lumped heat capacity method to obtain heat transfer correlations. The seven student groups plus the author produced 238 data points which were collectively correlated into two Nusselt number curves. The curve for the nonvented brakes simulation was benchmarked against the published literature for a cylinder in crossflow; the deviation was about 31%. The results from the vented brakes simulation which, in addition to the external air flow, had an internal radial flow driven by the rotation produced a 30% cooling augmentation over the nonvented simulation.
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Трушляков, Євген Іванович, Андрій Миколайович Радченко, Ян Зонмін, Анатолій Анатолійович Зубарєв та Веніамін Сергійович Ткаченко. "МЕТОД ВИЗНАЧЕННЯ ХОЛОДОПРОДУКТИВНОСТІ УСТАНОВОК КОНДИЦІЮВАННЯ ПОВІТРЯ КОМФОРТНОГО Й ЕНЕРГЕТИЧНОГО ПРИЗНАЧЕННЯ". Aerospace technic and technology, № 1 (7 березня 2019): 53–58. http://dx.doi.org/10.32620/aktt.2019.1.06.
Повний текст джерелаАнотація:
The efficiency of applying air conditioning units for comfort and energetics for a certain period, as well as any power plant, is determined by the effect obtained, primarily in the form of reducing fuel consumption over the year or increasing the production of electrical (mechanical) energy in the case of air conditioning at the heat engine inlet and by annual cold production as an indicator of the efficiency of using the cooling capacity of comfort air-conditioning plants. Since in both cases the effect depends on the duration and depth of cooling, it is quite justified to estimate it in the first approximation by the thermal hourly potential, which is the result of summation hour by hour of air temperature drops multiplied by duration of operation at a lowered temperature and, thus, takes into account current climatic conditions. Obviously, the realization of the cooling potential (air conditioning) of the ambient air depends on the installed (design) cooling capacity of the air conditioning units, which, in turn, must take into account the fluctuations in thermal loads in accordance with the current variable thermal and humidity parameters of the ambient air. Based on the different rates of the increment of the annual thermal hourly cooling potential with an increase in the installed cooling capacity of the air conditioning unit due to a change in the heat load in accordance with current climatic conditions during the year, it is necessary to choose such a design thermal load on the air conditioning unit (its installed cooling capacity) that ensures maximum or close to it the annual thermo-hour cooling potential at a relatively high rate of its increment, respectively, and the effect of cooling in the form of a decrease in fuel consumption per year in the case of air conditioning at the inlet of heat engine and annual cold production of comfort air conditioning units. It is shown that under the same climatic conditions during the year and the depth of ambient air cooling, the rational values of the design cooling capacity of air conditioning units for comfort and energy purposes are the same.
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Kitamura, Yoji, and Masaru Ishizuka. "Chimney Effect on Natural Air Cooling of Electronic Equipment Under Inclination." Journal of Electronic Packaging 126, no. 4 (December 1, 2004): 423–28. http://dx.doi.org/10.1115/1.1827256.
Повний текст джерелаАнотація:
With the rapid increase of the power dissipation density in modern electronic equipment, the cooling design of electronic equipment becomes increasingly important. For widely used forced-convection air-cooled systems, the reliability of and the acoustic noise of the fan present serious concerns as the air velocity is increased to enhance the cooling capacity. Thus, the interest in natural-convection air cooling is growing to take advantage of low noise and energy savings inherent in that cooling mode. One method of promoting the capacity of natural air cooling is to incline the electronics casing, thereby, induce draft air by what is called the chimney effect. However, the effect of inclination on thermal behavior and cooling capacity has not yet been fully understood due to the involvement of many parameters in driving the draft air. This paper presents the results of experimental and numerical studies on the effect of casing inclination on the temperature rise across the casing. The numerical simulation was implemented to find out the thermal behavior inside a thin electronic casing. The simulation results are in good agreement with the experiment data. A thermal design guide is obtained regarding how the cooling effect is improved by increasing the inclination angle.
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Buitendach, Henning, Immanuel Ninma Jiya, and Rupert Gouws. "Solar powered peltier cooling storage for vaccines in rural areas." Indonesian Journal of Electrical Engineering and Computer Science 17, no. 1 (January 1, 2020): 36. http://dx.doi.org/10.11591/ijeecs.v17.i1.pp36-46.
Повний текст джерелаАнотація:
The research presented in this paper proposes a new design of a vaccine cooling and storage unit that can keep vaccines in the cold chain (2°C to 8°C). This design was done to facilitate effective completion of the African vaccination week. The cooling and storage unit was designed to be compact, portable, well isolated and to make use of a PV solar energy system as a source of electricity. The cooling unit makes use of a Liquid to Air thermoelectric cooling module connected to some tubing and a liquid pump to cool the inside of the cooling unit. The design process also included designing a control system that controls the temperature inside the cooling holder and a monitoring system to monitor the battery voltage and capacity. The system also has a user interface that displays the temperatures inside and outside of the cooling holder, as well as the battery voltage and capacity. The cooling system successfully developed was able to keep vaccines in the cold chain for up to three days, the system could control the temperature of the vaccines with an accuracy of 1°C and was small and portable, but still had enough room to house up to 250 vaccines.
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Портной, Богдан Сергійович. "ВИБІР ТЕПЛОВОГО НАВАНТАЖЕННЯ АПАРАТІВ ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ ГТУ В РІЗНИХ КЛІМАТИЧНИХ УМОВАХ". Aerospace technic and technology, № 4 (14 жовтня 2018): 49–52. http://dx.doi.org/10.32620/aktt.2018.4.06.
Повний текст джерелаАнотація:
It is proposed the definition of the installed (rational) refrigeration capacity of a waste heat-recovery absorption-ejector chiller that utilizes the heat of the exhaust gases of a gas turbine unite to cool the air at the inlet. Since the effect of air cooling, in particular in the form of a reduction in the specific fuel consumption, depends on its depth (the magnitude of the decrease in air temperature) and duration, it is proposed to determine it by the annual fuel economy. As an example of air cooling at the inlet of a gas turbine unit, the value of reducing specific fuel consumption due to cooling the air at the inlet to the temperature of 15 °C by an absorption lithium-bromide chiller and two-stage air cooling: to a temperature of 15 °C in an absorption lithium-bromide chiller and down to 10 °C – in a refrigerant ejector chiller as the stages of a two-stage absorption-ejector chiller, depending on the installed (design) refrigeration capacity is analyzed.It is shown that proceeding from the different rate of increment of the annual reduction in the specific fuel consumption due to the change in the thermal load in accordance with the current climatic conditions, it is necessary to choose such design heat load for the air cooling system (installed refrigeration capacity of the chillers), which ensures the achievement of the maximum or close to annual reduction in the specific fuel consumption at relatively high rates of its increment. In order to determine the installed refrigeration capacity, which ensures the maximum annual refrigeration capacity (annual production of cold), the dependence of the increment of annual fuel economy from the installed refrigeration capacity is analyzed. Based on the results of the investigation, it was proposed to determine the rational thermal load of the air cooling system (installed - the design refrigeration capacity of the chiller) in accordance with the changing climatic conditions of operation during the year, which provides a maximum annual reduction in the specific fuel consumption at relatively high rates of its increment
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Yang, Zongming, Mykola Radchenko, Andrii Radchenko, Dariusz Mikielewicz, and Roman Radchenko. "Gas Turbine Intake Air Hybrid Cooling Systems and a New Approach to Their Rational Designing." Energies 15, no. 4 (February 17, 2022): 1474. http://dx.doi.org/10.3390/en15041474.
Повний текст джерелаАнотація:
Gas turbine intake air cooling (TIAC) by exhaust gas heat recovery chillers is a general trend to improve turbine fuel efficiency at increased ambient temperatures. The high efficiency absorption lithium–bromide chillers of a simple cycle are the most widely used, but they are unable to cool inlet air lower than 15 °C. A two-stage hybrid absorption–ejector chillers were developed with absorption chiller as a high temperature stage and ejector chiller as a low temperature stage to subcool air from 15 °C to 10 °C and lower. A novel trend in TIAC by two-stage air cooling in hybrid chillers has been substantiated to provide about 50% higher annual fuel saving in temperate climate as compared with absorption cooling. A new approach to reduce practically twice design cooling capacity of absorption chiller due to its rational distribution with accumulating excessive refrigeration energy at decreased thermal loads to cover the picked demands and advanced design methodology based on it was proposed. The method behind this is issued from comparing a behavior of the characteristic curves of refrigeration energy required for TIAC with its available values according to various design cooling capacities to cover daily fluctuation of thermal loads at reduced by 15 to 20% design cooling capacity and practically maximum annual fuel reduction.
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Радченко, Андрій Миколайович, Микола Іванович Радченко, Богдан Сергійович Портной, Сергій Анатолійович Кантор та Олександр Ігорович Прядко. "ВИКОРИСТАННЯ НАДЛИШКУ ХОЛОДОПРОДУКТИВНОСТІ ХОЛОДИЛЬНИХ МАШИН ПРИ ОХОЛОДЖЕННІ ПОВІТРЯ НА ВХОДІ ГТУ". Aerospace technic and technology, № 5 (29 серпня 2020): 47–52. http://dx.doi.org/10.32620/aktt.2020.5.06.
Повний текст джерелаАнотація:
The processes of the gas turbine inlet air cooling by exhaust heat conversion chillers, which utilizing the gas turbine exhaust gas heat, converting it into cold were analyzed. The use of two-stage air cooling has been investigated: to a temperature of 15°C – in an absorption lithium-bromide chiller and below to a temperature of 10°C – in an ejector chiller as stages of a two-stage absorption-ejector chiller. To simulate air cooling processes, the program "Guentner Product Calculator", one of the leading manufacturers of heat exchangers "Guentner", was used. The possibility of using the accumulated excess refrigeration capacity of a combined absorption-ejector chiller, which is formed at reduced current heat loads on air coolers at the gas turbine inlet, to cover the refrigeration capacity deficit arising at increased heat loads due to high ambient air temperatures has been investigated. The refrigeration capacity required to the gas turbine inlet air cooling was compared to an excess refrigeration capacity which excess of the current heat load. The considered air cooling system provides pre-cooling of air at the gas turbine inlet by using the excess refrigeration capacity of the absorption-ejector chiller, accumulated in the cold accumulator, to provide the required refrigeration capacity of the air pre-cooling booster stage. The simulation results proved the expediency of the gas turbine inlet air cooling using the accumulated excess refrigeration capacity of the combined absorption-ejector chiller. The proposed solution reduces by about 50% the design refrigeration capacity and, accordingly, the cost of the installed absorption lithium-bromide chiller, which acts as a high-temperature stage for cooling the ambient air at the gas turbine inlet.
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Zheng, W., W. M. Worek, and G. Nowakowski. "Effect of Operating Conditions on the Performance of Two-Bed Closed-Cycle Solid-Sorption Heat Pump Systems." Journal of Solar Energy Engineering 117, no. 3 (August 1, 1995): 181–86. http://dx.doi.org/10.1115/1.2847770.
Повний текст джерелаАнотація:
The effect of two operating parameters, the regeneration temperature and the ambient temperature, on the performance of two-bed, closed-cycle solid-sorption heat pumps is investigated. The results show that increasing the regeneration temperature can improve both the COP and cooling capacity, and the effect on cooling capacity is more significant than the COP. Increasing the regeneration temperature from 180°C to 260°C, the cooling capacity increases by 50 percent and the COP improves 20 percent. When the ambient temperature drops, the system performance increases significantly. When the ambient temperature decreases by 10°C from the design point of 35°C, the COP and cooling capacity increases by 50 percent and 40 percent, respectively. Also, the bed cycling speed should be increased to achieve the optimum system performance when the regeneration temperature is higher or the ambient temperature becomes lower.
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Silaipillayarputhur Ph. D, Karthik, Nasser Al Mulhim, Abdullah Al Mulhim, Mohammed Arfaj, and Ahmed Al Naim. "Basic design of a cooling system for nylon 6, 6 process." International Journal of Engineering & Technology 7, no. 3 (June 14, 2018): 977. http://dx.doi.org/10.14419/ijet.v7i3.9421.
Повний текст джерелаАнотація:
The project concentrates on the basic design of a cooling system for rapidly cooling nylon 6, 6 polymer fibers using cold air. The ambient air after pre-treatment in the air-washer is available at 72°F all year round. Based on the company’s throughput, it is required to supply (quench) air at 58°F. Nylon 6, 6 polymer after thorough polymerization is distributed through 16 quench cabinets and each quench cabinet requires approximately 530 ft3/min (cubic feet per minute, CFM) of air. The project concentrates on the basic design of a cooling system wherein air at the required mass flow rate is supplied at 58°F for the quenching process. A basic design of the refrigeration cycle and heat exchangers were considered in this work. In the development of the basic design for heat exchanger, performance charts were developed. Performance charts describe the performance of the heat exchanger in terms of fundamental dimensionless parameters. Using performance charts it was clearly seen that increasing the number of transfer units (NTU) doesn’t necessarily increase the rate of heat transfer. Increasing the NTU beyond an optimum value is pointless and increases the capital cost of the heat exchanger. The preliminary design involves selection of appropriate NTU and capacity rate ratio for the heat exchanger. From the capacity rate ratio and NTU, it is fairly straight forward to extrapolate the detailed design for the heat exchanger. A cooling system model was developed for the design process and for the simulation of the cooling system.
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Adams, William M., Erin E. Butke, Junyong Lee, and Mitchell E. Zaplatosch. "Cooling Capacity of Transpulmonary Cooling and Cold-Water Immersion After Exercise-Induced Hyperthermia." Journal of Athletic Training 56, no. 4 (February 4, 2021): 383–88. http://dx.doi.org/10.4085/1062-6050-0146.20.
Повний текст джерелаАнотація:
Context Cold-water immersion (CWI) may not be feasible in some remote settings, prompting the identification of alternative cooling methods as adjunct treatment modalities for exertional heat stroke (EHS). Objective To determine the differences in cooling capacities between CWI and the inhalation of cooled air. Design Randomized controlled clinical trial. Setting Laboratory. Patients or Other Participants A total of 12 recreationally active participants (7 men, 5 women; age = 26 ± 4 years, height = 170.6 ± 10.1 cm, mass = 76.0 ± 18.0 kg, body fat = 18.5% ± 9.7%, peak oxygen uptake = 42.7 ± 8.9 mL·kg−1·min−1). Intervention(s) After exercise in a hot environment (40°C and 40% relative humidity), participants were randomized to 3 cooling conditions: cooling during passive rest (PASS; control), CWI, and the Polar Breeze thermal rehabilitation machine (PB) with which participants inspired cooled air (22.2°C ± 1.0°C). Main Outcome Measure(s) Rectal temperature (TREC) and heart rate were continuously measured throughout cooling until TREC reached 38.25°C. Results Cooling rates during CWI (0.18°C·min−1 ± 0.06°C·min−1) were greater than those during PASS (mean difference [95% CI] of 0.16°C·min−1 [0.13°C·min−1, 0.19°C·min−1]; P < .001) and PB (0.15°C·min−1 [0.12°C·min−1, 0.16°C·min−1]; P < .001). Elapsed time to reach a TREC of 38.25°C was also faster with CWI (9.71 ± 3.30 minutes) than PASS (−58.1 minutes [−77.1, −39.9 minutes]; P < .001) and PB (−46.8 minutes [−65.5, −28.2 minutes]; P < .001). Differences in cooling rates and time to reach a TREC of 38.25°C between PASS and PB were not different (P > .05). Conclusions Transpulmonary cooling via cooled-air inhalation did not promote an optimal cooling rate (>0.15°C·min−1) for the successful treatment of EHS. In remote settings where EHS is a risk, access and use of treatment methods via CWI or cold-water dousing are imperative to ensuring survival. Trial Registry ClinicalTrials.gov (NCT0419026).
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Rahnama, Samira, Peter Vilhelm Nielsen, Alireza Afshari, Niels Christian Bergsøe, Hicham Johra, and Rasmus Lund Jensen. "Evaluating the cooling capacity of diffuse ceiling ventilation system – Full-scale experimental study." E3S Web of Conferences 111 (2019): 02006. http://dx.doi.org/10.1051/e3sconf/201911102006.
Повний текст джерелаАнотація:
Diffuse ceiling ventilation system is an air distribution system in which part of the suspended ceiling made of perforated panels is used as an air diffuser for the supply of fresh air. This method has been proven to have a higher cooling capacity compared to conventional air distribution systems. The cooling capacity of the system, however, depends on several parameters. This paper presents evaluation results regarding the cooling capacity of the diffuse ceiling ventilation system in connection to two essential parameters, i.e. the distribution of heat sources in the room and the ratio of perforated to non-perforated panels in the ceiling. The evaluation is based on full-scale experiments performed in a laboratory controlled environment and using a design chart which expresses the limits on the supply airflow rate and temperature. The experimental results indicate that the highest cooling capacity is achieved when the heat sources are distributed evenly and the perforated panels cover the entire ceiling. In the case of partial coverage, the cooling capacity is reduced when the heat sources are placed below the perforated panels. The system can have a higher cooling capacity in the partial coverage configuration compared to the full coverage one depending on the supply airflow rate.
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Aziz, Azridjal, Rahmat Iman Mainil, Afdhal Kurniawan Mainil, Sayfri Syafri, and Muhammad Faizal Syukrillah. "Design of Portable Beverage Cooler Using One Stage Thermoelectric Cooler (TEC) Module." Aceh International Journal of Science and Technology 6, no. 1 (April 17, 2017): 29. http://dx.doi.org/10.13170/aijst.6.1.5427.
Повний текст джерелаАнотація:
The Portable Beverage Cooler (PBC) has been designed to satisfy the need of cooler apparatus that could be carried easily. The utilization of this apparatus was intended to minimize the environmental damage affected by vapour compression refrigeration system using CFCs Refrigerant. The peltier effect from thermoelectric module was utilized in this PBC and called as Thermoelectric Cooler (TEC). Furthermore, heat-sink and fan were needed to ensure the cooling effect continously worked. To achieved the objectives of this machine (portable, environment-friendly, low watt, affordable), the design consideration are heat load, insulating material, weight of components, electric consumption, and dimension of the cooling box. The results of the design shows the PBC cooling box dimension is 6 cm x 6.5 x 15 cm. The insulation of the PBC cooling box are polyurethane foam and polystyrene expanded with thickness 6 mm and 5.3 mm, respectively. The alumunium plate was applied as inner wall to enhance the cooling capacity of cooling room temperature. In this PBC was used one stage of TEC that could yield cooling room temperature until 15 oC in 30 minutes operation by consuming 20 W of electricity.
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Farhan, Muhammad, Muhammad Amjad, Zia Tahir, Zahid Anwar, Muhammad Arslan, Ahmad Mujtaba, Fahid Riaz, et al. "Design and analysis of liquid cooling plates for different flow channel configurations." Thermal Science, no. 00 (2021): 196. http://dx.doi.org/10.2298/tsci201111196f.
Повний текст джерелаАнотація:
A number of thermal management devices are used to actuate concentrated electronic appliances in an efficient way. A liquid cooling plate acts as a heat sink enclosed by materialized walls. This work aims to carry out design of liquid cooling plates such that the heat diffused by the electronic equipment is removed while their temperatures levels remain within safe limits. The liquid cooling plates expose ?cold surfaces? to electronic appliances. The performance of a cooling plate is estimated depending upon heat carrying capacity, associated heat transfer rates and concentrated thermal regions on the plate surface. For this study, the design of liquid cooling plate was done with SOLIDWORKS. Pure water was used as a working fluid in test channels. A comparative analysis of flow distribution, temperature contours, pressure drop and pumping power for different channel configurations was carried out with ANSYS. It was observed that a channel configuration is of key importance in liquid cooling plates. The findings from this study are beneficial for the optimum design of cooling systems for high heat flux applications, i.e., in electronic devices, computer processors and automotive engines.
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Radchenko, Andrii, Eugeniy Trushliakov, Krzysztof Kosowski, Dariusz Mikielewicz, and Mykola Radchenko. "Innovative Turbine Intake Air Cooling Systems and Their Rational Designing." Energies 13, no. 23 (November 25, 2020): 6201. http://dx.doi.org/10.3390/en13236201.
Повний текст джерелаАнотація:
The efficiency of cooling ambient air at the inlet of gas turbines in temperate climatic conditions was analyzed and reserves for its enhancing through deep cooling were revealed. A method of logical analysis of the actual operation efficiency of turbine intake air cooling systems in real varying environment, supplemented by the simplest numerical simulation was used to synthesize new solutions. As a result, a novel trend in engine intake air cooling to 7 or 10 °C in temperate climatic conditions by two-stage cooling in chillers of combined type, providing an annual fuel saving of practically 50%, surpasses its value gained due to traditional air cooling to about 15 °C in absorption lithium-bromide chiller of a simple cycle, and is proposed. On analyzing the actual efficiency of turbine intake air cooling system, the current changes in thermal loads on the system in response to varying ambient air parameters were taken into account and annual fuel reduction was considered to be a primary criterion, as an example. The improved methodology of the engine intake air cooling system designing based on the annual effect due to cooling was developed. It involves determining the optimal value of cooling capacity, providing the minimum system sizes at maximum rate of annual effect increment, and its rational value, providing a close to maximum annual effect without system oversizing at the second maximum rate of annual effect increment within the range beyond the first maximum rate. The rational value of design cooling capacity provides practically the maximum annual fuel saving but with the sizes of cooling systems reduced by 15 to 20% due to the correspondingly reduced design cooling capacity of the systems as compared with their values defined by traditional designing focused to cover current peaked short-term thermal loads. The optimal value of cooling capacity providing the minimum sizes of cooling system is very reasonable for applying the energy saving technologies, for instance, based on the thermal storage with accumulating excessive (not consumed) cooling capacities at lowered current thermal loads to cover the peak loads. The application of developed methodology enables revealing the thermal potential for enhancing the efficiency of any combustion engine (gas turbines and engines, internal combustion engines, etc.).
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Keawkamrop, Thawatchai, and Somchai Wongwises. "Effect of Cycle Frequency of a Reciprocating Magnetic Refrigerator Prototype on the Temperature Span and Cooling Capacity." International Journal of Air-Conditioning and Refrigeration 27, no. 01 (March 2019): 1950002. http://dx.doi.org/10.1142/s2010132519500020.
Повний текст джерелаАнотація:
Magnetic refrigeration is an environment-friendly cooling technology and an interesting potential replacement for the vapor compression refrigeration system. This paper presents a linear reciprocating magnetic refrigerator prototype that operates at room temperature by using gadolinium parallel plates under a maximum magnetic field intensity of 0.94[Formula: see text]T. The design, installation and preliminary results are reported. The temperature span and cooling capacity are studied in a function of cycle frequency, and the results show the cycle frequency effects on temperature span and cooling capacity. The maximum temperature span and cooling capacity for cycle frequency of 0.16[Formula: see text]Hz are 1.3[Formula: see text]K and 4.68[Formula: see text]W, respectively. The results from the experiment will be a guideline to determine the maximum performance of the magnetic refrigerator prototype.
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Ridwan, Abrar, Nasruddin, Awaludin Martin, and Arfie I. Firmansyah. "DESIGN, MANUFACTURING AND TESTING KINETIC ADSORPTION TEST RIG." Photon: Jurnal Sain dan Kesehatan 2, no. 1 (October 30, 2011): 1–5. http://dx.doi.org/10.37859/jp.v2i1.119.
Повний текст джерелаАнотація:
Adsorption on a solid adsorbent is the fundamental processes in the field of separation processes, purification of gases, adsorption cooling, advanced adsorption cooling, and extensive work on hydrogen storage. The understanding of the thermodynamic properties of adsorbent plus adsorbate system is important to analyze. Information concerning the relevant adsorption equilibrium and characterized of adsorbent is generally an essential requirement for the analysis and design of an adsorption separation process. For practical application, theadsorption equilibrium must be known over a broad range of operation temperatures. Also, the isotherms of pure species are fundamental information for dynamic simulation of adsorbers. The main objective of this research is to design kinetic adsorption test rig to investigate the capacity and rate of adsorption on adsorbent and adsorbate pair’s. The result of design kinetic adsorption test rig including dimensions of vapor vessel (pressure vessel) and measuring cell. The volume of vapour vessel is 1000 ml and measuring cell is 100 ml. Kinetic adsorption test rig was manufactured to investigate capacity and rate of adsorption up to 40 bar.
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Qiang, Xuhong, Nianduo Wu, Xu Jiang, Frans Bijlaard, and Henk Kolstein. "Performance assessment on high strength steel endplate connections after fire." Journal of Structural Fire Engineering 8, no. 2 (June 12, 2017): 202–14. http://dx.doi.org/10.1108/jsfe-11-2016-0018.
Повний текст джерелаАнотація:
Purpose This study aims to reveal more information and understanding on performance and failure mechanisms of high strength steel endplate connections after fire. Design/methodology/approach An experimental and numerical study on seven endplate connections after cooling down from fire temperature of 550°C has been carried out and reported herein. Moreover, the provisions of European design standard for steel structures, Eurocode 3, were validated with test results of high strength steel endplate connections. Findings In endplate connections, a proper design using a thinner high strength steel endplate can achieve the same failure mode, similar residual load bearing capacity and comparable or even higher rotation capacity after cooling down from fire. It is found that high strength steel endplate connection can regain more than 90 per cent of its original load bearing capacity after cooling down from fire temperature of 550°C. Originality/value The post-fire performance of high strength steel endplate connection has been reported. The accuracy of Eurocode 3 for endplate connections is validated against test results.
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Et.al, Anoop Kumar M. "Modelling and thermodynamic analysis of ejector flow for application at design and off design operating conditions in an ejector air conditioner." Turkish Journal of Computer and Mathematics Education (TURCOMAT) 12, no. 3 (April 11, 2021): 3455–67. http://dx.doi.org/10.17762/turcomat.v12i3.1617.
Повний текст джерелаАнотація:
Ejector flow in an ejector air conditioning system using R245fa is analysed for entrainment ratio and potential refrigeration effect, at varying temperature and heat input conditions in the generator ranging from 60C to 100C and 2kW to 5kW respectively. The effect of varying generator temperature in cooling capacity of the system when the vapour ejectoris operating at design evaporator and condenser temperatures of 10C and 35C respectively is investigated. The mathematical model of the vapour ejector with optimum area ratio is developed and validated. A critical entrainment ratio of 0.385 is obtained corresponding to generator temperature of 100C. When the generator temperature is varied from 60C to 100C, the cooling capacity range from 0.3kW at generator heat input of 2 kW to 1.78 kW at 5 kW heat input. Further, the operation of the system is analysed for off design operating condition corresponding to reduced heat input rate in the generator. In that case the state of primary refrigerant flow in ejector inlet will be two phase and a mathematical model for two-phase ejector flow is developed and validated. Ejector flow analysis revealed the minimum quality of flow at ejector inlet to maintain adequate backpressure for condensation to occur range from 0.72 at 60C to 0.22 at 100C. The corresponding refrigeration refrigeration effect produced is less than the respective designed operation value byits 12.2% to 8%. Further, analysis of the system shows that at least 7 kW heat input at 100C is required to produce 1 ton of cooling effect.
Ejector flow in an ejector air conditioning system using R245fa is analysed for entrainment ratio and potential refrigeration effect, at varying temperature and heat input conditions in the generator ranging from 60C to 100C and 2kW to 5kW respectively. The effect of varying generator temperature in cooling capacity of the system when the vapour ejectoris operating at design evaporator and condenser temperatures of 10C and 35C respectively is investigated. The mathematical model of the vapour ejector with optimum area ratio is developed and validated. A critical entrainment ratio of 0.385 is obtained corresponding to generator temperature of 100C. When the generator temperature is varied from 60C to 100C, the cooling capacity range from 0.3kW at generator heat input of 2 kW to 1.78 kW at 5 kW heat input. Further, the operation of the system is analysed for off design operating condition corresponding to reduced heat input rate in the generator. In that case the state of primary refrigerant flow in ejector inlet will be two phase and a mathematical model for two-phase ejector flow is developed and validated. Ejector flow analysis revealed the minimum quality of flow at ejector inlet to maintain adequate backpressure for condensation to occur range from 0.72 at 60C to 0.22 at 100C. The corresponding refrigeration refrigeration effect produced is less than the respective designed operation value byits 12.2% to 8%. Further, analysis of the system shows that at least 7 kW heat input at 100C is required to produce 1 ton of cooling effect.
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Alamayreh, Malik I., Ali Alahmer, Mai Bani Younes, and Subhi M. Bazlamit. "Pre-Cooling Concrete System in Massive Concrete Production: Energy Analysis and Refrigerant Replacement." Energies 15, no. 3 (February 3, 2022): 1129. http://dx.doi.org/10.3390/en15031129.
Повний текст джерелаАнотація:
Several techniques for cooling mass concrete structures were developed in order to increase structural integrity and reduce the influence of cement hydration, which sometimes causes cracking in concrete structures, negatively affecting their durability. This research focuses on cooling system design, initial investment, and the influence of different refrigerants on cooling system performance aims in producing higher quality massive concrete. Cooling aggregates in massive concrete structures such as desert dams can be performed by employing cooled air from an air conditioning duct system or chilled water. The experimental study illustrates the relationship between the coefficient of performance COP, the evaporator temperature, cooling capacity, and refrigerant mass flow rate as a function of the evaporator temperature, cooling capacity, and refrigerant mass flow rate. The findings of the experiments were utilized to verify a numerical model developed utilizing engineering equation solver (EES) software. The performance of the vapor compression of the cooling systems was compared using alternative refrigerants, including R22, R32, and R410a at different operating conditions. This study revealed that R22 refrigerant has a higher coefficient of performance than R32 and R410A, while R32 has the highest cooling capacity among other refrigerants.
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Fielding, J. P., and M. A. F. Vaziry-Z. "Avionics cooling-rate trade-off modelling for ultra-high capacity aircraft." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 211, no. 6 (June 1, 1997): 403–12. http://dx.doi.org/10.1243/0954410971532767.
Повний текст джерелаАнотація:
A computer aided conceptual aircraft design methodology (CACAD) has been developed to size ultra-high capacity jet transport aircraft. Modules were also developed for predicting maintenance costs of each airframe and avionics system and these were incorporated into CACAD. A methodology was developed to enhance the reliability of avionics systems, based on experimentally-proven engineering design solutions. A number of avionics cooling techniques were investigated, and reliability and maintainability models of thermal management were developed and linked to an avionics maintenance cost module. Further models were produced to investigate the impact of proposed changes on the environmental control systems, engine-provided bleeds and power off-takes. It was found that increased flowrates above the normally recommended values for the avionics bay, and to the flight deck instruments, may increase the reliability of the avionics systems, and also increase aircraft dispatch reliability. They may not, however, greatly improve direct operating costs (DOC), due to significant fuel penalties. A separate refrigeration unit was investigated and found to be a feasible cost-effective measure, even allowing for increased engine fuel consumption caused by the effect of the engine power off-take required to drive the refrigeration unit.
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Портной, Богдан Сергійович, Андрій Миколайович Радченко, Роман Миколайович Радченко та Сергій Анатолійович Кантор. "ВИКОРИСТАННЯ РЕЗЕРВУ ХОЛОДОПРОДУКТИВНОСТІ АБСОРБЦІЙНОЇ ХОЛОДИЛЬНОЇ МАШИНИ ПРИ ОХОЛОДЖЕННІ ПОВІТРЯ НА ВХОДІ ГТУ". Aerospace technic and technology, № 3 (27 червня 2018): 39–44. http://dx.doi.org/10.32620/aktt.2018.3.05.
Повний текст джерелаАнотація:
The processes of air cooling at the gas turbine unit inlet by absorption lithium-bromide chiller have been analyzed. The computer programs of firms-producers of heat exchangers were used for the gas turbine unit inlet air cooling processes simulation. The absorption lithium-bromide chiller refrigeration capacity reserve (the design heat load excess over the current heat loads) generated at the reduced current heat loads on the air coolers at the gas turbine unit inlet in accordance with the lowered ambient air parameters has been considered. The absorption lithium-bromide chiller refrigeration capacity reserve is expedient to use at increased heat load on the air cooler. To solve this problem the refrigeration capacity required for cooling air at the gas turbine unit inlet has been compared with the excessive absorption lithium-bromide chiller refrigeration capacity exceeding current heat loads during July 2017.The scheme of gas turbine unit inlet air cooling system with using the absorption lithium-bromide chiller refrigeration capacity reserve has been proposed. The proposed air cooling system provides gas turbine unit inlet air precooling in the air cooler booster stage by using the absorption lithium-bromide chiller excessive refrigeration capacity. The absorption chiller excessive refrigeration capacity generated during decreased heat loads on the gas turbine unit inlet air cooler is accumulated in the thermal storage. The results of simulation show the expediency of the gas turbine unit inlet air cooling by using the absorption lithium-bromide chiller refrigeration capacity reserve, which is generated at reduced thermal loads, for the air precooling in the air cooler booster stage. This solution provides the absorption lithium-bromide chiller installed (designed) refrigeration capacity and cost reduction by almost 30%. The solution to increase the efficiency of gas turbine unit inlet air cooling through using the absorption chiller excessive refrigeration potential accumulated in the thermal storage has been proposed.