Academic literature on the topic 'Oil-freezing system'

Cryogel based oil encapsulation was attempted with a ternary system of colloidal chitosan, κ-carrageenan, and carboxymethylcellulose sodium salt (NaCMC). Favourable formulations of this ternary system that caused irreversible sol-gel transition by freezing (cryogelation) were found in this study, and the oil phase that contained a selected model food ingredient (curcumin) was successfully encapsulated in this prepared cryogel matrix. The encapsulation yields were found to vary from ca 89 to 99%, and the values were influenced by the cooling protocol used during freezing, thereby indicating that the gel formation kinetics was intimately related to the degree of encapsulation. The release behaviours of the ingredient were investigated in aqueous systems. The release curves showed that both a burst release and a first order release were achieved simply by changing the freezing condition. Freezing could modify the gel formation of the present cryogel, and the resulting structural modification evidently controlled the oil encapsulation manner. The prepared cryogels were found to be sensitive to the ambient pH. It was suggested that the ternary system of chitosan, κ-carrageenan, and NaCMC is an interesting matrix for designing controlled release system.

In view of the problems of low permeability, high oil viscosity and freezing point, and low productivity of single well in Luo 321 and Luo 36 blocks of Luojia Oilfield, the chemical viscosity-reducing cold production technology was studied. By analyzing the properties of crude oil, it is concluded that the reason for high viscosity and high freezing point is the high content of asphaltene, pectin, and wax. The viscosity is mainly affected by asphaltene; the wax precipitation point and pour point are mainly affected by the wax; and the solidification point is affected by the wax and asphaltene. The treatment idea of reducing viscosity and inhibiting wax is determined. By compounding the synthetic pour point depressant POA-VA and the viscosity reducer DBD-DOPAMA, the effect of reducing the viscosity and freezing point of crude oil was evaluated. PD-7 (POA-VA 40%, DBD-DOPAMA 50%, and P-10C 10%) system was selected as the optimal formula. When the concentration of the system is 10%, the viscosity reduction rate reaches 95.2%; the freezing point can reduce by 10.2°C; it has good oil sample adaptability, salinity resistance, and temperature resistance; and the oil washing rate can reach more than 60%. The oil displacement system was injected into the formation by means of multiconcentration and multislug and was applied in the field of Luo 321-2 Well. A total of 500 t of the oil displacement system was injected, and the effect of measures lasted for 400 days, with a cumulative oil increase of 883 t. It has been applied in different blocks 30 times and achieved a good field application effect.

The goal of this work is to study the influence of low-frequency acoustic field and polymer additive on structural and mechanical properties of problematic quick-freezing oil. The results were acquired by methods of rotational viscosimetry and finding phase transition temperatures by using optical density of infrared light as well as optical microscopy method. Highly paraffinic low-resin oil (Tomsk region) was exposed to low-frequency acoustic field (f = 50 Hz, 1 and 3 min of processing at 0 °С), a chemical reagent, the complex-action polymer additive D-210 (0.05% mass concentration in oil) and complex physical-chemical processing This work studies external influence on viscosity, temperature and energy characteristics, phase transition temperature as well as structure of oil residue. It was shown that in the case of problematic oil at a temperature close to freezing point, the acoustic influence leads to increase of viscosity and temperature properties. After adding the additive to processed oil during the complex processing, the thixotropic structure is destroyed, which is followed by a sharp decrease in viscosity, cloud point and freezing point. There is also a decrease in energy parameters, such as activation energy of viscous flow and internal energy of a disperse system. To determine the temperature of spontaneous crystallization we plotted the differential curves of viscosity coefficient dependence on the temperature of the medium. Study of the microstructure of the oil residue had shown that it contains small linear single-crystal and spherical formations prior to acoustic processing. After processing, however, such formations display a significant growth. The structure of the residue after complex processing is represented by many large plate paraffin crystallites.

The study aimed to investigate and evaluate the oxidative stability of chicken thighs with skin stored in freezing conditions due to the effect of oregano essential oil for various times. The results were compared with a control group without the use of oregano essential oil. Samples of chicken thighs with skin were obtained from an experiment performed on a poultry farm in a deep litter breeding system. The results obtained from the application of oregano essential oil to chicken thighs with skin did not show a statistically significant difference (p >0.05) in the dry matter content, fat content and acid value compared to the control group, where coccidiostats were used in starter and growth feed mixtures. A statistically significant difference was found in the peroxide value by applying oregano essential oil to chicken thighs with skin compared to a control group containing coccidiostats in starter and growth feed mixtures when stored for 1 day at room temperature (p £0.01) and 12 months in freezing conditions at -18 °C (p £0.05) and a statistically non-significant difference (p >0.05) when thighs with skin were stored for 6 and 9 months in -18 °C freezing conditions. In the conclusion, it was stated that maintaining the oxidative stability of chicken meat means knowing the factors that affect it and prepare the conditions for its maintenance. Chicken meat is generally susceptible to oxidative damage because it is characterized by a high concentration of polyunsaturated fatty acids. With a sufficient amount of effective antioxidants, chicken meat could be a homoeostatic system, but it remains limited or free of oxidized compounds and reactive components. These questions are the subject of further research in the field of oxidative stability of chicken meat.

Solar collector water heating system use solar thermal energy to provide hot water for domestic and industrial use. These systems are operated either as open-loop or closed-loop flow circuit. The former loop systems are not recommended for the cold climates having water freezing problem. Although previous studies on solar collectors have used closed-loop operation with water as the working fluid; however, it must have high boiling and low freezing points for the colder regions and thus arises the need for antifreeze mixtures of water. Another solution to the same problem is the use of heat transfer oil as intermediate working fluids. In the present study, the energy and exergy analysis of a boiler supported vacuum tube solar collector system working with closed-loop in different working fluid flow rates have been performed and evaluated. Heat transfer oil has been used as an intermediate working fluid in the closed loop system at different flow rates of 0.277 kg/s, 0.383 kg/s, 0.494 kg/s. The results show that the collector temperature difference as well as the outlet temperature decrease; however, the collector inlet temperature increases by increasing the flow rate. Moreover, with the increase in flow rate, it was ascertained that the energy and exergy efficiency of the system and the collectors increase. The main finding of the present study is that the intermediate fluid used in the closed-circuit operation of the solar collectors has a direct effect on the energy and exergy efficiency of the system.

Physicochemical aspects of enhanced oil recovery (EOR) from heavy high-viscosity deposits, developed in natural mode and combined with thermal methods, using systems based on surface-active substances (surfactants), coordinating solvents and complex compounds are considered, which chemically evolve in situ to acquire colloidal-chemical properties that are optimal for oil displacement. Thermobaric reservoir conditions, interactions with reservoir rock and fluids are the factors causing the chemical evolution of the systems. To enhance oil recovery and intensify the development of high-viscosity deposits, acid oil-displacing systems of prolonged action based on surfactants, inorganic acid adduct and polyatomic alcohol have been created. As a result of experimental studies of acid-base equilibrium in the systems with donor-acceptor interactions – polybasic inorganic acid and polyol, the influence of electrolytes, non-electrolytes and surfactants, the optimal compositions of the systems were selected, as well as concentration ranges of the components in the acid systems. When the initially acid system interacts with the carbonate reservoir to release CO2, the oil viscosity decreases 1.2-2.7 times, the pH of the system rises and this system evolves chemically turning into an alkaline oil-displacing system. As a result it provides effective oil displacement and prolonged reservoir stimulation. The system is compatible with saline reservoir waters, has a low freezing point (minus 20 ÷ minus 60 oC), low interfacial tension at the oil boundary and is applicable in a wide temperature range, from 10 to 200 oC. In 2014-2018 field tests of EOR technologies were successfully carried out to intensify oil production in the test areas of the Permian-Carboniferous deposit of high-viscosity oil in the Usinsk oil field, developed in natural mode and combined with thermal-steam stimulation, using the acid oil-displacing system based on surfactants, coordinating solvents and complex compounds. The pilot tests proved high efficiency of EOR technologies, as far as the oil production rate significantly increased, water cut decreased to intensify the development. The EOR technologies are environmentally safe and technologically effective. Commercial use of the EOR is promising for high-viscosity oil deposits.

he existence of oil-water transition layer brings a great trouble to the dehydration of oil gathering and transportation system. It leads to raising the electric current of dehydrator and becoming worse of the deoiling and dehydrating properties of the treatment equipment, resulting in the serious influences on oil recovery. For the efficient treatment of the transition layer, it is necessary clearly to understand the structure and composition of the layer. In this paper, the physical structure and chemical composition of the layer were systematically, layer by layer and phase by phase, analyzed by modern instrumental methods The results show that (1）the layer is an emulsion which is composed of oil, water and suspended solids. The water phase has characteristics of weak alkaline，high salinity and viscous polymer. The oil phase contains many natural emulsifiers such as colloid, asphaltene and so on. The solid phase mainly concludes FeS particle which plays a decisive role in suspended solids; (2) the typical transition layer is composed of water and oil which accounts for above 90%, the content of solid impurity, which controls the emulsion of the layer, is less than 10%. Compared with oil phase, the water content of typical transition layer is larger with the density of 0.9~1.0 g/L and high freezing point. The analytical data can be adopted for the treatment of oil-water transition layer and smoothly run operations for oil gathering and transportation.

The crude oil in Kuidong region of Liaohe Tanhai Oilfield is characterized by high oil viscosity, high density, high content of colloid asphalt, low content of wax and low freezing point. In the shallow region, the large current, high content of silt, long-distance subsea buried pipeline and drift ice in winter have brought great challenge to offshore construction and oil-gas transportation. In this paper, the investigations of offshore construction project and platform process are shown. Based on the well production rate, gas-oil ratio, water cut, wellhead back pressure and outlet temperature, the range of daily transportation volume was acquired, as well as the maximum inlet pressure and pressure difference of the pump. The paper also selected technically and economically feasible pumps, then designed the public projects, corresponding electric power and self-control facilities. The selected skidded twin screw multiphase pump system can smoothly transport produced liquid to the terminal systems onshore without any effect on the daily output.

Low- and high-alkali, plain and air-entrained large concrete cylinders, 255 mm in diameter by 310 mm in length, were made with a highly alkali–silica reactive limestone. After curing, a number of cylinders were sealed with silane, oligosiloxane, polysiloxane, linseed oil, or epoxy, with others subjected to 179 freezing and thawing cycles in humid air (one cycle per day). All cylinders were then subjected to 14-day exposure cycles, including in the most severe case periods of humid storage in air, drying, wetting in salt water, and freezing and thawing cycles. All low-alkali specimens did not either expand or develop surface cracking, even those with a deficient air void system and exposed to freezing and thawing cycles. All unsealed high-alkali cylinders subjected early to a series of freezing and thawing cycles did not significantly expand during these cycles, but presented high expansion afterwards. Wetting and drying significantly reduced alkali–silica reaction (ASR) expansion compared with constant humid storage; however, it promoted map-cracking. Regardless of the air content, freezing and thawing increased greatly the concrete expansion in the presence of ASR, even after ASR was almost complete; freezing and thawing also greatly promoted surface cracking. On the other hand, all cylinders early sealed with silane, oligosilixane, or polysiloxane did not either significantly expand or show map-cracking, whatever the exposure conditions and the air content; these cylinders progressively lost mass with time. On the other hand, the epoxy resin was not effective. The linseed oil prevented map-cracking while significantly reducing expansion, however not sufficiently. After one or 1.5 years, some expanding cylinders were sealed with silane, oligosiloxane, or polysiloxane; they started to loose mass and contracted immediately after being sealed, whatever the exposure conditions. The results obtained thus indicate that a good sealer may greatly improve the aesthetic appearance (e.g., map-cracking) and stop expansion of ASR-affected concrete elements of 255 mm or less in thickness, made with a water-to-cement ratio in the range of 0.50, and exposed to wetting and drying, freezing and thawing, and salt water.Key words: air entrained, alkali–silica reaction, concrete, cracking, expansion, freezing and thawing, sealer, silane, siloxane, wetting and drying.

A characteristic wedge-shaped iron ( Fe ) film system, deposited on glass substrate by a DC-magnetron sputtering method and quenched by silicone oil during deposition, has been successfully fabricated. The mechanical behaviors of the quenched and non-quenched Fe films have been compared and analyzed. The internal stress is found to transform from tension to compression in nature after quenching, which results in the formation of buckling pattern in the quenched Fe film while crack pattern in the non-quenched film. It is proposed that the origin of the compressive stress is mainly due to freezing of the Fe atoms (or clusters) with high kinetic energy and doping of the oil molecules into the Fe film defects.

Дисертація на здобуття наукового ступеня кандидата технічних наук (доктора філософії) за спеціальністю 05.05.16 "Турбомашини та турбоустановки", (технічні науки). – Національний технічний університету "Харківський політехнічний інститут", Міністерство освіти і науки України, Харків, 2018. Дисертацію присвячено вирішенню важливої науково-технічної задачі вдосконалення систем охолодження газових турбін шляхом подальшого розвитку методів гідравлічного і теплового розрахунку каналів системи охолодження газових турбін. Вивченню структури і властивості потоку в цих елементах, отриманню залежностей, описуючих цей потік. Виконано аналіз науково-технічної літератури, присвяченій проектуванню систем охолодження ГТД, в якому розглянуто міжнародний досвід експериментальних досліджень і обчислювальних експериментів, що до дослідження теплообміну і гідродинаміки течії в обертових елементах. В результаті аналізу літератури показано що, основним напрямом розвитку ефективних і надійних систем охолодження ГТД є підвищення точності розрахунку витратних і гідравлічних характеристик елементів системи охолодження. Показано, що на моделювання процесів впливає геометрія каналу, направлення течії (відцентрове, доцентрове), наявність супутних потоків, параметри і властивості (повітря, масло-повітря) охолоджуючого середовища. Тому від точності, з якою буде змодельований окремий елемент, залежить надійність моделювання всієї системи охолодження. Проведено адаптацію математичних моделей елементів гідравлічних мереж для розрахунку систем охолодження газових турбін, таких як: апарат закручування потоку (АЗ), теплообмінник, канали, що переміщуються. Наведено опис, теоретичні основи моделювання цих елементів гідравлічної схеми, проведені чисельні дослідження по впливу апарата закручування і теплообмінника на ефективність охолодження, складені відповідні моделі систем охолодження. Встановлено, що ефективність охолодження при застосуванні АЗ збільшується на 15%. Запропоновано підхід включення в загальну гідравлічну схему теплообмінника, при загальному наборі початкових даних, які відображають роботу теплообмінника в змінному режимі. Проведено дослідження впливу відцентрового ефекту на можливість подачі повітря в порожнини ротора турбіни. Розглянуті приклади течії повітря в порожнинах, утворених двома паралельними дисками з осьовою або радіальною подачею повітря на периферійному радіусі. Проведений CFD аналіз показав, що в залежності від напрямку подачі повітря істотно змінюється характер течії в порожнині. При радіальній подачі повітря в напрямку осі обертання має місце безвихровий характер течії, при осьовій - з'являється вихор. Проте, відмінність в характері течії майже не позначається на величині протитиску, який перешкоджає переміщенню повітря. Визначено діапазон достовірності результатів методу розрахунку насосного ефекту в придискових порожнинах роторів газових турбін, а саме: відношення ширини порожнини до зовнішнього радіуса диска не перевищує величину 0,17, що дозволяє обґрунтовано використовувати цей метод для розрахунків систем охолодження. Розроблено узагальнений підхід до методу розрахунку коефіцієнтів витрати і гідравлічного опору елементів систем охолодження газових турбін таких, як отвори, потовщені діафрагми, лабіринтові ущільнення, які регламентують витрату охолоджуючого повітря і відповідають за надійність і економічність системи охолодження. Так як розрахунок гідравлічної схеми застосовує коефіцієнти гідравлічного опору кожної ділянки схеми, а експериментальні дані часто представленні коефіцієнтами витрати, тому встановлено зв'язок між ними за допомогою припущень, які враховують різницю між стисливим і нестисливим середовищами. На основі проведених досліджень, обґрунтовано поправку на стисливість до коефіцієнту гідравлічного опору подовжених діафрагм, отворів, лабіринтових ущільнень, яка уточнює коефіцієнт гідравлічного опору до 25%. Розроблено математичну модель розрахунку підшипника, описані підходи до визначення концентрації і термодинамічних характеристик двофазного гомогенного середовища, що дозволило включити підшипник як в гідравлічну, так і теплову моделі систем охолодження газових турбін. Розроблено метод розрахунку гідравлічної мережі для маслоповітряної суміші, який істотно розширив можливості моделювання процесів охолодження роторів і підшипників газових турбін і маслозабезпечення підшипників, що дозволило провести спільний розрахунок системи охолодження ротора турбіни і підшипників. Проведено дослідження системи охолодження ротора високотемпературної газової турбіни за допомогою розроблених методів розрахунку. Встановлено, що методи розрахунку відповідають робочим даним газотурбінного двигуна Д 36.
The dissertation for the degree of Candidate of Technical Sciences (Ph. D.) in the specialty 05.05.16 "Turbomachine and turbine plants", (technical sciences). National Technical University "Kharkiv Polytechnical Institute", Ministry of Science and Science of Ukraine, Kharkiv, 2018. Dissertation is devoted to solving an important scientific and technical task of improving the cooling systems of gas turbines by further developing the methods of hydraulic and thermal calculation of the channels of the cooling system of gas turbines. To study the structure and flow properties of these elements, to obtain the dependences describing this flow. The analysis of scientific and technical literature devoted to the design of cooling systems for gas turbine engines was carried out, in which international experience of experimental studies and computational experiments was considered, to the study of heat transfer and flow hydrodynamics in rotating elements. As a result of the analysis of the literature, it is shown that the main direction of development of efficient and reliable GTE cooling systems is to improve the accuracy of the calculation of the flow and hydraulic characteristics of the elements of the cooling system. It is shown that the modeling of processes is influenced by the channel geometry, flow direction (centrifugal, centripetal), presence of associated flows, parameters and properties (air, oil-air) of the cooling medium. Therefore, the accuracy with which the simulation of the entire cooling system depends on the accuracy with which the individual element will be modeled. Mathematical models of hydraulic network elements have been adapted to calculate gas turbine cooling systems, such as: a device for swirling flow, a heat exchanger, channels that are moved. Description, theoretical bases of modeling of these elements of a hydraulic circuit, the researches carried out on the influence of the apparatus of the twist and the heat exchange apparatus on the efficiency of cooling are given, the corresponding models of cooling systems are made. Impact study conducted of the centrifugal effect on the possibility of air supply in the cavity of the rotor of the turbine has been studied. The considered examples of air flow in cavities formed by two parallel disks with axial or radial air supply at a peripheral radius. CFD analysis showed that, depending on the direction of air supply, the nature of the flow in the cavity is significantly changed. At radial air supply in the direction of the axis of rotation there is a non-vortex nature of the flow, with axial - vortex occurs. However, the difference in the nature of the flow almost does not affect the magnitude of the back pressure, which impedes the movement of air. The range of reliability of the results of the calculation method of the pump effect in the disk cavities of the rotors of the gas turbines is determined, namely: the ratio of the width of the cavity to the external radius of the disk does not exceed the value of 0.17, which allows us to use this method reasonably for calculations of the cooling systems. Developed a generalized approach to the method of calculating the flow coefficients and the hydraulic resistance of elements of the cooling systems of gas turbines such as openings, thickened diaphragms, labyrinth seals, regulating the flow of cooling air, which are responsible for the reliability and economy of the cooling system. In the calculations of the hydraulic circuit, the hydraulic resistance coefficients of each section of the circuit are used, and the experimental data are often represented by flow coefficients. Therefore, a connection is established between them using assumptions that take into account the difference between compressible and incompressible media. On the basis of the research, justified correction for compressibility to the coefficient of hydraulic resistance of elongated diaphragms, holes, labyrinth seals, which specifies the coefficient of hydraulic resistance to 25%. A mathematical model for calculating the bearing has been developed, approaches have been described for determining the concentration and thermodynamic characteristics of a two-phase homogeneous medium, which made it possible to include the bearing in both the hydraulic and thermal models of gas turbine cooling systems.A method was developed for calculating the hydraulic network for the air-oil mixture, which significantly expanded the possibilities for simulating the cooling processes of the rotors and bearings of gas turbines and providing bearings with oil, which made it possible to jointly calculate the cooling system of the turbine rotor and bearings. A study of the cooling system of the rotor of a high-temperature gas turbine was carried out using the developed calculation methods. It is established that the calculation methods correspond to the working data of the D-36 gas turbine engine.

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.05.16 – турбомашини та турбоустановки, (технічні науки). – Національний технічний університету "Харківський політехнічний інститут", Міністерство освіти і науки України, Харків, 2018. Розроблено методи розрахунку повітряного охолодження і систем маслозабезпечення, які дозволяють отримати якісно нові результати, що сприяють підвищенню надійності проектування системи охолодження ГТУ. Удосконалено метод розрахунку повітряного охолодження за рахунок введення нових елементів таких, як апарат закручування, теплообмінник які розширюють можливості проектування системи охолодження ГТУ і ГТД. Набув подальший розвиток метод розрахунку гідравлічних мереж систем охолодження газових турбін з урахуванням закручування потоку в міждискових порожнинах. Обґрунтовано надійне застосування методу розрахунку насосного ефекту в придискових порожнинах роторів в діапазоні відношення ширини до зовнішнього радіусу диска s/r₂ = 0,17. Розвинений метод розрахунку гідравлічного опору подовжених діафрагм, отворів, лабіринтових ущільнень з урахуванням стисливості середовища Обґрунтовано поправку на стисливість до коефіцієнту гідравлічного опору, що уточнює коефіцієнт гідравлічного опору до 25%. Розроблена сумісна математична модель і метод розрахунку гідравлічного опору двофазного гомогенного середовища, що дозволяє моделювати процеси охолодження і маслозабезпечення в межах загального методу гідравлічного розрахунку системи охолодження, і проводити спільний розрахунок системи охолодження ротора турбіни і підшипників.
The dissertation for the degree of the Candidate of Technical Sciences (Ph.D.) in the specialty 05.05.16 turbomachine and turbine plants, (technical sciences). National Technical University "Kharkiv Polytechnical Institute", Ministry of Science and Science of Ukraine, Kharkiv, 2018. Developed methods for calculating air cooling and oil supply systems allow us to expand the possibilities by introducing new elements such as heat exchanger, labyrinth seals, bearings, as well as obtaining qualitatively new results that increase the reliability of the design of the cooling system of the GT. The reliable application of the method of calculating the pumping effect in the disk cavities of gas turbine rotors in the range of the ratio of width to the outer disk radius s/r₂ = 0,17 is substantiated. The method is developed for calculating the hydraulic resistance of elongated diaphragms, holes, labyrinth seals, considering the compressibility of the medium. The investigated effect on the hydraulic resistance of the angle of the hole. The correction for compressibility to the coefficient of hydraulic resistance of elongated diaphragms, holes, labyrinth seals is justified, that corrects coefficient of hydraulic resistance to 25%. Developed in conjunction mathematical model and a method for calculating the hydraulic resistance of a two-phase homogeneous medium that significantly expands the modeling capabilities of cooling processes and oil supply within the general method of hydraulic calculation of the cooling system, which allowed a joint calculation of the cooling system of the turbine rotor and bearings.

Abstract The dissolution of light components in crude oil would increase its saturated vapor pressure, and easy to produce losses during the storage and transportation process. However, the crude oil containing light hydrocarbons has better flowing properties and rheological properties under low temperature. Compared with degassed crude oil, the viscosity, yield stress and freezing point of dissolved-gas crude oil have been improved obviously. On the basis of analyzing energy consumption of the gathering system and total energy cost of pipeline operation, the improved gathering and transportation process without the device in stabilizing crude oil will be considered. The new process mode not only makes the overall upstream of the gathering and transportation system be airtight, but also has the advantages of simple process, less equipment, high degree of automation and convenient management. It helps to form an integrated three-links structure among joint station, pipeline and refinery, which is of a huge energy-saving potential to the environment and safe operation of the gathering and transportation system with crude oil pipelines.

The petroleum leakage has been a serious problem these years in China. The leakage, mostly caused by human destruction, lasting a short time with a large amount of loss, is not only an economic loss for the petroleum company, but environmental pollution, a public issue. Thus a monitoring system, which can identify the leakage and locate the leak point in real time, is required. One of the challenges is the sensitivity of the system. The system is expected to respond quickly to locate the point so that the security personnel can find and mend the orifice in time. Another challenge is the accuracy of the locating result. Because of the features of Chinese petroleum: high viscosity, high wax content and high freezing point, the sound wave speed in the oil is not a constant along the pipeline and the leak point calculated by the traditional negative pressure wave method are invalid. In this paper, a modified negative pressure wave method was put forward according to the variation of the wave speed. A wavelet-based algorithm applied to calculate the leak point gives fairly satisfied results. The data acquisition, signal processing and the structure of the pipeline leakage monitoring system (PLMS) were analyzed. The system has played a big role on the pipeline network in Shengli Oil Field and long pipelines of East China Oil Bureau.

Thermal energy storage systems are designed to store extra heat in order to release it at a more appropriate time. There are many industrial applications that can utilize the thermal energy storage concept, such as oil drilling and solar power generation. A model depicting the operation of a dual–tank molten salt thermal energy storage system was developed to be used to optimize its charging and discharging operations. Thermal energy storage systems are very well insulated; nonetheless, molten salt is constantly losing small amounts of its heat to the ambient because of the large temperature gradient across the surface of the holding tanks. Consequently, auxiliary heaters are always attached to thermal energy storage systems to prevent salt freezing during extended periods of little or no thermal energy input, such as lengthy cloud cover periods in solar thermal power plants.

The present generation of commercial parabolic trough solar power plant uses a synthetic oil as the heat transport fluid in the collector field. The plants are currently operating at the upper temperature limit of the fluid, and further improvements in the solar-to-electric conversion efficiency are likely to be incremental. In contrast, adoption of a nitrate salt, or a nitrate/nitrite salt, mixture as the heat transport fluid would allow the collector field outlet temperature to increase by 50 to 100 °C, which translates into an increase in the gross Rankine cycle efficiency from the present 37.5 percent to new values in the range of 40 to 41 percent. Further, the low cost and the low vapor pressure of the candidate salt mixtures allow the heat transport fluid to also act as the storage medium in a thermal storage system. Using a salt mixture in the collector field should reduce the unit cost of thermal storage by approximately half compared to the current indirect designs. The principal, and far from minor, liability of the candidate salt mixtures are freezing points in the range of 120 °C to 220 °C. As a consequence, all salt components, including the collector field, will require some form of electric heating for freeze protection. Further, collector designs will need to be demonstrated, or developed, which are tolerant of a limited number of freeze/thaw cycles. The candidate salts are also corrosive to the current ball joint sealing materials. This paper outlines the problems which need to be solved before a commercial salt project could reasonably be considered by a project developer, the elements of a test and demonstration program to solve the problems, and the contributions which will be necessary from the salt component vendors, the project developers, and the financial community.

Elevators designed to suspend tubing and drilling pipes in tripping operations are complex structures in petroleum drilling processes. Due to complexity of structure of elevators designed to suspend tubing in tripping operations used in oil well service, many stress geometrical concentration zones occur, and the three dimensional stresses can’t be calculated accurately with sufficient precision and easily by analytical and numerical procedures. To determine and optimise the real stresses occurring at these structures, the photoelasticity method is used reliably. Three dimensional models made from optically sensitive materials and freezing of strains technique are applied to analyse the stresses throughout in the present analysis. The obtained results can be applied to test the currently existing package programmes and to write new computer algorithmes for the related systems.