Lithium-bromide Chiller Research Articles

РЕЗЕРВИ ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ ТРАНСФОРМАЦІЇ ТЕПЛОТИ УСТАНОВКИ АВТОНОМНОГО ЕНЕРГОЗАБЕЗПЕЧЕННЯ

It is analyzed the efficiency of heat conversion in the integrated electricity, heat and cooling supply of the enterprise. The installation for energy supply includes two JMS 420 GS-N.LC GE Jenbacher cogeneration gas engines manufactured as cogeneration modules with heat exchangers for removing the heat of exhaust gases, scavenge gas-air mixture, cooling water of engine and lubricating oil. The heat of hot water is transformed by the absorption lithium-bromide chiller AR-D500L2 Century into the cold, which is spent on technological needs and for the operation of the central air conditioner for cooling the incoming air of the engine room, where from it is sucked by the turbocharger of the engine. The presence of significant heat losses, which account for about 30% of the total heat removed from the cogeneration gas piston module and is due to the inconsistency of the joint operation modes of the absorption lithium-bromide chiller and the gas piston engine, was revealed. This inconsistency is caused by the contradictory conditions of their effective operation according to the temperature of the return coolant at the outlet of the absorption lithium-bromide chiller and the entrance to the engine cooling system. The thermal state of the gas piston engine is ensured by maintaining the temperature of the return coolant at the entrance to it is not higher than 70 °C. At the same time, during the transformation of the heat of the coolant into the cold in an absorption lithium-bromide chiller, the temperature decreasing in the machine is no more than 10 ... 15 °С, that is, up to 75 ... 80 °С, if the temperature of the heat coolant outlet from the cogeneration gas piston module, i.e. at the inlet of the absorption lithium-bromide chiller, 90 °С. Therefore, the return coolant is additionally cooled in the "emergency heat release" radiator by removing its heat into surroundings. It is shown the possibility of increasing the cooling capacity of the system by conversion of the return coolant exhaust heat into cold in absorption lithium-bromide and ejector chillers through the data procession of monitoring the heat conversion system in the integrated energy plant.

ЕКОЛОГІЧНА ЕФЕКТИВНІСТЬ ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ ГТУ В РІЗНИХ КЛІМАТИЧНИХ УМОВАХ

The operation of gas turbine unites significantly depends on the ambient air temperature at the inlet, and the higher it is, the greater the specific fuel consumption is spent for the production of a unit capacity (mechanical/electrical energy), 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 gas turbine units at elevated ambient temperatures, the inlet air cooling is applied. The paper studies the ecological efficiency of gas turbine unite inlet air cooling, taking into account the variable climatic operation conditions for regions with different climatic conditions over a period of five years (2014-2018): temperate climate of Ukraine (on the example of cities Sumy and Ternopol) and the subtropical climate of the PRC (cities Beijing and Nanjing). 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 deeper cooling gas turbine unite inlet air to 7...10 °C provides almost a half to two times greater reduction in specific fuel consumption, respectively, and harmful emissions compared with traditional cooling to 15 °C by the most widespread absorption lithium-bromide chillers, and for the temperate climate of Ukraine the relative effect is much greater than for the subtropical climatic conditions of the PRC. Reducing carbon dioxide CO2 over five years for the PRC climate when cooling air to 10 °C is approximately more than 500 t, and for Ukraine – more than 240 t, and NOX nitric oxide – about 3.5 t for China and 1.6 t for Ukraine, while with traditional cooling to 15 °C: more than 300 t for China, and for Ukraine about 120 t, and nitric oxide NOX – about 2 t for China and 0.7 t for Ukraine. Based on the results of a rough assessment of the environmental effect of cooling the ambient air at the inlet of gas turbine units, in the temperate climate of Ukraine, deep cooling of the air is especially advisable, which provides almost twice the effect compared with traditional cooling to 15 °C.

АНАЛІЗ ЕФЕКТИВНОСТІ ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ КОГЕНЕРАЦІЙНОГО ГАЗОПОРШНЕВОГО МОДУЛЯ НА ЧАСТКОВИХ НАВАНТАЖЕННЯХ

The fuel efficiency of the reciprocating gas engine deteriorates with the increase of ambient air temperatures at the inlet to the radiator of the recirculating cooling water system for cooling the scavenge gas/air mixture at the inlet of the working cylinders and the air at the inlet of the scavenge air turbocharger. The peculiarity of cogeneration reciprocating gas modules of plants for combined production of electricity, heat, and cold is the operation mainly at partial loads according to the schedules of consumption of electricity, heat, and cold. The efficiency of cooling air of cogeneration gas module on the partial loads was analyzed on the example of an integrated power supply installation, which includes two cogeneration reciprocating gas engines JMS 420 GS-N.LC GE Jenbacher, manufactured as the cogeneration modules with exchangers using the heat of exhaust gases, scavenge gas-air mixture, cooling water of the engine shirt and lubricating oil for heating water. Hot water heat is transformed by the AR-D500L2 Century absorption lithium-bromide chiller into a cold that is spent on technological needs and for the operation of a central air conditioner that cools the engine room income air from where it is sucked by a scavenge air turbocharger. Because of significant heat influx from working engines and other equipment, as well as through the enclosures of the engine room from the outside to the air-cooled in the central air conditioner in the engine room, from where it is sucked by a turbocharger, the air temperature at the inlet of the turbocharger is quite high: 25...30 °C. At elevated temperatures of the ambient air at the inlet of the radiator for cooling scavenge gas-air mixture and the air at the turbocharger inlet the fuel economy of engine is falling, which indicates the need for efficient cooling of air. The efficiency of cooling the air of the reciprocating gas module was estimated by a reduction in the consumption of gas fuel and an increase in electric power of the engine. For this purpose, the data of monitoring on the fuel efficiency of the reciprocating gas engine with the combined influence of the ambient air temperature at the inlet of the radiator and the air at the turbocharger inlet were processed to obtain data on their separate effects and to determine the ways to further improve the air cooling system of the reciprocating gas module.

АНАЛІЗ ЕФЕКТИВНОСТІ ОХОЛОДЖЕННЯ ПОВІТРЯ КОГЕНЕРАЦІЙНОГО ГАЗОПОРШНЕВОГО МОДУЛЯ УСТАНОВКИ АВТОНОМНОГО ЕНЕРГОЗАБЕЗПЕЧЕННЯ

The analysis of the efficiency of cooling air of cogeneration gas-piston module of installations for combined production of electric energy, heat, and cold is performed. The installation for energy supply includes two JMS 420 GS-N.LC GE Jenbacher cogeneration gas-piston engines manufactured as cogeneration modules with heat exchangers for removing the heat of exhaust gases, scavenge gas-air mixture, cooling water of engine and lubricating oil. The heat of hot water is transformed by the absorption lithium-bromide chiller AR-D500L2 Century into the cold, which is spent on technological needs and for the operation of the central air conditioner for cooling the incoming air of the engine room, wherefrom it is sucked by the turbocharger of the engine. The temperature of the scavenge gas-air mixture at the entrance to the working cylinders of the engine is maintained by the system of recirculating cooling with the removal of its heat into surroundings by the radiator. Because of significant heat influx from working engines and other equipment, as well as through the enclosures of the engine room from the outside to the air-cooled in the central air conditioner in the engine room, from where it is sucked by a turbocharger, the air temperature at the inlet of the turbocharger is quite high: 25...30 °C. At elevated temperatures of the ambient air at the inlet of the radiator for cooling scavenge gas-air mixture and the air at the turbocharger inlet the fuel economy of engine is falling, which indicates the need for efficient cooling of air. The efficiency of cooling the air of the gas-piston module was estimated by a reduction in the consumption of gaseous fuel and the increase in electric power of the engine. For this purpose, the data of monitoring on the fuel efficiency of the gas-piston engine with the combined influence of the ambient air temperature at the inlet of the radiator and the air at the turbocharger inlet were processed to obtain data on their separate effects and to determine the ways to further improve the air cooling system of the gas-piston module.

Simulating and experimental research on a low-concentrating PV/T triple-generation system

A low-concentrating photovoltaic/thermal triple-generation system for heating, cooling and electricity is proposed in this study. The main components of the system are the low-concentrating PV/T module, high-temperature water source heat pump, lithium bromide absorption chiller and capillary net radiant ceiling. The annual system performance and the optimal capacity configuration of each component are stimulated by Transient System Simulation Program software. In addition, the outdoor experiments are carried out on the roof of a building in Changping, Beijing. In winter, the hot water produced by the low-concentrating PV/T module enters the heat pump evaporator for further heating, then through the pipes and enters the capillary net for building heating. In summer, the hot water enters an absorption lithium bromide chiller. The chilled water from the chiller enters the capillary net and lowers the room temperature. The experiments are conducted under different radiation conditions. The main parameters of the system are recorded. The results show that, under the low concentration condition, the system produces hot water of 45 °C–90 °C; meanwhile, the efficiency of PV cells stabilized approximately 10%. The lithium bromide absorption chiller operates stably, with the COP above 0.5. The low-concentrating PV/T triple-generation system provides a new idea for the comprehensive utilization of solar energy and energy cascade utilization.

МОДЕЛЮВАННЯ ПРОЦЕСІВ ОХОЛОДЖЕННЯ ПОВІТРЯ БРОМИСТОЛІТІЄВОЮ ХОЛОДИЛЬНОЮ МАШИНОЮ З ВИКОРИСТАННЯМ РЕЗЕРВУ ХОЛОДОПРОДУКТИВНОСТІ У БУСТЕРНОМУ ПОВІТРООХОЛОДЖУВАЧІ

The heat-humidity processes of gas turbine unit intake air cooling to the temperature of above 15 °C with the use of a cold water at the temperature of about 10 °C as a coolant and the absorption lithium-bromide chiller utilizing the turbine exhaust gas waste heat as a thermotransformer has been analyzed for daily changing ambient air temperatures and changeable heat loads on the air coolers as consequence. The computer programs of the firms-producers of heat exchangers were used for gas turbine unit intake air cooling processes simulation. It is shown that at decreased heat loads on the air cooler a surplus cooling capacity of the absorption lithium-bromide chiller exceeding current heat loads is generated which can be used for covering an increased heat loads on the air cooler and to reduce the cooling capacity of the absorption lithium-bromide chiller applied. To solve this task the cooling capacity required for gas turbine unit intake air cooling are compared with the surplus cooling capacity of the absorption lithium-bromide chiller exceeding current heat loads summarized during some period.The system of two-stage gas turbine unit intake air cooling with a buster stage of precooling air to the temperature of about 15 °C and a base stage of further cooling air to the temperature of about 15 °C by absorption lithium-bromide chiller as the base stage has been proposed. The water for a buster stage of precooling air is cooled by using the surplus cooling capacity of the absorption lithium-bromide chiller during decreased heat loads on the two-stage gas turbine unit intake air cooler and is collected in the thermal accumulator for the use during increased heat loads on the air cooler. The results of gas turbine unit intake air cooling processes simulation proved the reduction of cooling capacity of the absorption lithium-bromide chiller applied by 30-40 % due to the use of a buster stage of precooling air at the expanse of the surplus cooling capacity of absorption lithium-bromide chiller saved in the thermal accumulator. So the main conclusion has been made about the efficient use of such a two-stage air cooling with a buster stage of precooling air by surplus cooling capacity from the thermal accumulator and a base stage for further cooling air to the temperature of about 15 °C by an absorption lithium-bromide chiller as a perspective approach in refrigeration.

ОЦІНКА ЕФЕКТИВНОСТІ ГЛИБОКОГО ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ ГАЗОТУРБІННИХ УСТАНОВОК В РІЗНИХ КЛІМАТИЧНИХ УМОВАХ

The efficiency of deep air cooling at the inlet of gas turbine units of a simple scheme has been investigated for changed climatic conditions of operation during the month. For air cooling, the application of waste heat recovery chiller has been proposed, which transform the heat of exhaust gases of gas turbine units into the cold. The efficiency of air cooling at the inlet of gas turbine units to different temperatures has been analyzed: to 15°C – an absorption lithium-bromide chiller, which is used as the first high-temperature pre-cooling stage of ambient air and down to 10°C – a combined absorption-ejector chiller, which acts as the second low-temperature stage. The air cooling efficiency is compared for different climatic conditions using the example of Yuzhnoukrainsk (Ukraine) and Shanghai (China). The climate peculiarity of Shanghai is the high relative humidity of the air, respectively, and its moisture contents at the same time its high temperatures. As indicators for assessing the effectiveness of air cooling at the inlet of gas turbine units down to 15°C in an absorption lithium-bromide chiller and deep air cooling to 10ºС, in a combined absorption-ejector chiller used an increase in useful power and a reduction in specific fuel consumption. It is shown that, through extremely different thermal and humidity parameters of ambient air, it is cooling at the inlet of gas turbine units for the climatic conditions of Ukraine provides the current increase in useful power by 10...15%, and for the climatic conditions of China – 18…22%. However, it should be noted that deeper air cooling at the inlet of the gas turbine unite to a temperature of 10°C in a combined absorption-ejector chiller compared to its traditional cooling to 15°C in an absorption lithium-bromide chiller provides an increase in useful power for a temperate climate of Ukraine (for example, Yuzhnoukrainsk) by 70...90%, whereas for tropical climatic conditions of China (Shanghai) – by 30...35%.

Hierarchical Multi-Objective Fuzzy Collaborative Optimization of Integrated Energy System under Off-Design Performance

In order to solve the frequently occurred nonlinear working characteristics problem of the devices in integrated energy system (IES), where this nonlinear problem causes the offset of operation characteristics and design points of those devices, in this paper, the hierarchical multi-objective fuzzy collaborative optimization model of IES under off-design performance is proposed. Firstly, the high-order nonlinear models of devices under off-design performance, including fuel cell (FC), gas turbine (GT), absorption lithium bromide chiller (ABS), etc., are presented considering renewable energy and diversified storage devices, which can more accurately describe the actual working condition of devices. Secondly, according to the needs of different engineering application modes, the lower level collaborative optimization model of energy hub (EH) with economic, eco-friendly, primary energy saving, and renewable energy accommodation rate as optimization objectives is proposed, which can well adapt to and reflect real world energy system. Thirdly, based on the relationship between master and slave dispatch centers, the upper level modeling and optimal scheduling model of IES consisting of coupling power system, natural gas system, and heat system is proposed. Then, a multi-objective fuzzy collaborative optimization model for EH and IES is developed, where continuous differentiable Sigmoid function is taken as the membership function. Finally, simulation results show that the proposed models and optimal dispatch method can effectively solve the frequently occurred non-linear working characteristics problem of the devices in IES. The optimal results are suitable for planning, calculation, operation, dispatch of IES, which can reasonably reflect the operation characteristics of IES.

A new approach to increasing the efficiency of the ship main engine air waste heat recovery cooling system

The efficiency of integrated cooling air at the intake of Turbocharger and Scavenge air at the inlet of working cylinders of the main diesel engine of dry-cargo ship by transforming the waste heat into a cold by an Refrigerant Ejector Chiller (ECh) as the most simple in design and reliable in operation and by complex in design but more efficient Absorption Lithium-Bromide Chiller (ACh) was analyzed. A ship power plant of cogeneration type using the relatively low-grade heat of water of a heat supply system with a temperature of about 90 °C, that significantly complicates the problem of its conversion into cold were considered. Because of the insufficiently high efficiency of transformation of the heat of hot water (low coefficient of performance) as compared with steam, the resulting cooling capacity may not be enough for cooling intake air of the turbocharger and scavenge air, that raises the problem of the rational distribution of heat loads between the Turbocharger Intake Air cooling circuit (subsystem) and Scavenge air cooling circuit and the need to use chillers of various types. This takes into account the rational parameters of cooling processes of the scavenge air in the cogeneration high-temperature stage of scavenge air cooler, in the intermediate stage of traditional cooling air with seawater, and in the low-temperature stage for deep cooling of the scavenge air by using a chiller. A new approach is proposed to improve the efficiency of integrated cooling Intake Air of the turbocharger and Scavenge Air at the inlet of the working cylinders of the ship main engine of a transport ship, which consists in comparing the required cooling capacity and the corresponding heat needs during the trade route with the available heat of exhaust gases and scavenge air of the cogeneration power plant, determining the deficit and excess cooling capacity of heat utilizing cooling machines of various types, that allows to identify and realize the reserves of improving the efficiency of cooling intake air of the turbocharger and the scavenge air of the main diesel engine through the joint use of chillers of various types.

Analyzing the efficiency of moderate and deep cooling of air at the inlet of gas turbine in various climatic conditions

The efficiency of deep cooling air at the inlet of gas turbine unite to the temperature of 10 °С by waste heat recovery combined absorption-ejector chiller was analyzed in climatic conditions at Kharkov site, Ukraine, and Beijing site, China, and compared with the moderate cooling to the temperature of 15°C in traditional absorption lithium-bromide chiller. The refrigerant ejector chiller is chosen as the most simple and reliable in operation chiller. It was used as the low-temperature stage for subcooling the air precooled in absorption lithium-bromide chiller to the temperature about 15 °C. Both waste heat recovery absorption lithium-bromide chiller and ejector chiller use the heat of gas turbine unite exhaust gas to produce a cooling capacity. Air cooling at the inlet of gas turbine unite was investigated for varying climatic conditions during the year. The current values of temperature depression with cooling ambient air to different temperatures of 10 °C and 15 °C and corresponding cooling capacities required were calculated. The comparison of the effect due to gas turbine unite inlet air cooling was performed by annual fuel saving and power production growth. With this the current values of turbine power output increase and specific fuel consumption decrease due to cooling inlet air from current varying ambient temperatures to the temperatures of 10 °C and 15 °C were calculated. It was shown that annual fuel saving and power production growth have increased by 1,8 times for Kharkov (Ukraine) site climatic conditions and by 1,6 times for Beijing (China) site due to deep cooling air to the temperature of 10 °C by absorption-ejector chiller as compared with cooling inlet air to the temperature of 15 °C by absorption lithium-bromide chiller.

ВИКОРИСТАННЯ РЕЗЕРВУ ХОЛОДОПРОДУКТИВНОСТІ АБСОРБЦІЙНОЇ ХОЛОДИЛЬНОЇ МАШИНИ ПРИ ОХОЛОДЖЕННІ ПОВІТРЯ НА ВХОДІ ГТУ

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.

ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ ГТУ З ВИКОРИСТАННЯМ РЕЗЕРВУ ХОЛОДОПРОДУКТИВНОСТІ АБСОРБЦІЙНО-ЕЖЕКТОРНОЇ ХОЛОДИЛЬНОЇ МАШИНИ В БУСТЕРНОМУ ПОВІТРООХОЛОДЖУВАЧІ

The processes of gas turbine unit two-stage intake air cooling by absorption lithium-bromide chiller as a high temperature cooling stage to the temperature of about 15 °C and by refrigerant ejector chiller as a low temperature cooling stage to the temperature of about 10 °C through utilizing the turbine exhaust gas waste heat for hour-by-hour changing ambient air temperatures and changeable heat loads on the air coolers as consequence during 10 days of July 2017 (10–12.07.2017) for climatic conditions of the south of Ukraine are analyzed. The computer programs of the firms-producers of heat exchangers were used for gas turbine unit inlet air cooling processes simulation.It is shown that at decreased heat loads on the air coolers an excessive refrigeration capacity of combined absorption-ejector chiller exceeding current heat loads is generated which can be used for covering increased heat loads on the air coolers and to reduce the refrigeration capacity of the absorption-ejector chiller. To solve this task the refrigeration capacity required for gas turbine unit inlet air cooling is compared with an excessive refrigeration capacity of the absorption-ejector chiller exceeding current heat loads summarized during 10 days.The system of gas turbine unit inlet air cooling with a booster stage of precooling air and a base two-stage cooling air to the temperature of about 10 °C by absorption-ejector chiller has been proposed. An excessive refrigeration capacity of the absorption-ejector chiller generated during decreased heat loads on the gas turbine unit inlet air coolers that is collected in the thermal accumulator is used for gas turbine unit inlet air precooling in a booster stage of air coolers during increased heat loads on the air coolers. The results of gas turbine unit inlet air cooling processes simulation proved the reduction of refrigeration capacity of the absorption-ejector chiller by about 50 % due to the use of a booster stage for precooling air at the expanse of an excessive absorption-ejector chiller refrigeration capacity served in the thermal accumulator. The conclusion has been made about the efficient use of a booster stage of gas turbine unit inlet air cooler for precooling air by using an excessive refrigeration potential of absorption-ejector chiller saved in the thermal accumulator

ПОЛУЧЕНИЕ КОНДЕНСАТА КАК СОПУТСТВУЮЩЕГО ПРОДУКТА ОХЛАЖДЕНИЯ ВОЗДУХА НА ВХОДЕ ГАЗОТУРБИННОЙ УСТАНОВКИ

The processes of gas turbine unit inlet air cooling with generation of condensate as a subproduct were investigated. The heat-humidity processes in the two-stage air cooler of combined type with the first low temperature cooling stage were water with temperature of about 7 °C as a coolant for precooling air from the changeable ambient temperature to the temperature not lower than 15 °C is used and low temperature cooling stage with a refrigerant boiling at the temperature of 2-4 °C as a coolant for further deep cooling air to the temperature of about 10 °C by utilizing the exhaust gas waste heat in the absorption lithium-bromide chiller as the high temperature cooling stage and refrigerant ejector chiller as the low temperature cooling stage of the combined thermotransformer has been analyzed for daily changing ambient air temperatures and heat loads on the stages as consequence. The processes of generating the condensate as a subproduct of gas turbine unit intake air two-stage cooling were simulated by using the computer simulation programs of the firms-producers of heat equipment for more than twice decreased heat load upon the high temperature cooling stage as compared with a heat load upon the low temperature cooling stage. The data about amount of condensate extracted in each air cooler stage was summed up over a day, three days and July and its temperature was calculated. The results of calculation have shown that the temperature of condensate received in the refrigerant low temperature cooling stage are lower by about 4 °C as compared with its value for high temperature cooling stage with a chilled water temperature of 7 °C from absorption lithium-bromide chiller. It was also shown that inspite of intensive changeable current temperatures of condensate from each and both stages mean weighted values of temperature of condensate from both stages of a combined two-stage air cooler remained nearly unchangeable during days. A conclusion about using the condensate from low temperature cooling stage as a coolant has been made

ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ ГТУ З ВИКОРИСТАННЯМ РЕЗЕРВУ ХОЛОДОПРОДУКТИВНОСТІ АБСОРБЦІЙНОЇ ХОЛОДИЛЬНОЇ МАШИНИ В БУСТЕРНОМУ ПОВІТРООХОЛОДЖУВАЧІ

The processes of gas turbine unit inlet air cooling by absorption lithium-bromide chiller utilizing the turbine exhaust gas waste heat as athermotransformer has been analyzed for hour-by-hour changing ambient air temperatures and changeable heat loads on the air cooler as consequence. The computer programs of the firms-producers of heat exchangers were used for gas turbine unit inlet air cooling processes simulation. It is shown that at decreased heat loads on the air cooler an excessive refrigeration capacity of the absorption lithium-bromidechiller exceeding current heat loads is generated which can be used for covering increased heat loads on the air cooler and to reduce the refrigeration capacity of the absorption lithium-bromidechiller applied. To solve this task the refrigeration capacity required for gas turbine unit inlet air cooling is compared with an excessive refrigeration capacity of the absorption lithium-bromidechiller exceeding current heat loads summarized during 10 days of July 2015. The system of gas turbine unit inlet air cooling with a buster stage of precooling air and a base stage of cooling air to the temperature of about 15 °C by absorption lithium-bromide chiller has been proposed. An excessive refrigeration capacity of the absorption chiller generated during decreased heat loads on the gas turbine unit inlet air cooler that is collected in the thermal accumulator is used for gas turbine unit inlet air precooling in a buster stage of air cooler during increased heat loads on the air cooler. The results of gas turbine unit inlet air cooling processes simulation proved the reduction of refrigeration capacity of the absorption lithium-bromide chiller applied by 30-40 % due to the use of a buster stage of precooling air at the expanse of an excessive absorptionchiller refrigeration capacity served in the thermal accumulator. So the conclusion has been made about the efficient use of a buster stage of gas turbine unit inlet air cooler for precooling air by using an excessive refrigeration potential of absorption lithium-bromidechiller coolant saved in the thermal accumulator

Increasing electrical power output and fuel efficiency of gas engines in integrated energy system by absorption chiller scavenge air cooling on the base of monitoring data treatment

An advanced scavenge air cooling system for reciprocating gas engines of integrated energy system for combined electricity, heat and refrigeration generation has been developed. New method of deep scavenge air cooling and stabilizing its temperature at increased ambient air temperatures and three-circuit scavenge air cooling system with absorption lithium-bromide chiller and wet-type cooling tower was proposed. Such cooling method does not require essential constructive changes in the existing scavenge air cooling system but only an addition heat exchanger for chilling scavenge air cooling water of scavenge air low-temperature intercooler closed contour by absorption chiller. A chilled water from absorption chiller is used as a coolant. To evaluate the effect of gas engine scavenge air deeper cooling compared with its typical radiator cooling, data on the dependence of fuel consumption and power output of gas engine on ambient air temperature at the inlet of the radiator are analized. The efficiency of engine scavenge air deep cooling at increased ambient air temperatures was estimated by reducing the gas fuel consumption compared with radiator cooling.

Gas turbine unite inlet air cooling by using an excessive refrigeration capacity of absorption-ejector chiller in booster air cooler

Two-stage Gas turbine unite (GTU) inlet air cooling by absorption lithium-bromide chiller (ACh) to the temperature 15 °C and by refrigerant ejector chiller (ECh) to 10 °C through utilizing the turbine exhaust gas heat for changeable ambient air temperatures and corresponding heat loads on the air coolers for the south Ukraine climatic conditions is analysed. An excessive refrigeration capacity of combined absorption-ejector chiller (AECh) exceeding the current heat loads and generated at decreased heat loads on the air coolers at the inlet of GTU can be used for covering increased heat loads to reduce the refrigeration capacity of AECh. The GTU inlet air cooling system with an ambient air precooling booster stage and a base two-stage cooling air to the temperature 10 °C by AECh is proposed. The AECh excessive cooling capacity generated during decreased heat loads on the GTU inlet air coolers is conserved in the thermal accumulator and used for GTU inlet air precooling in a booster stage of air cooler during increased heat loads. There is AECh cooling capacity reduction by 50% due to the use of a booster stage for precooling GTU inlet ambient air at the expense of an excessive cooling capacity accumulated in the thermal storage.

ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ ВИКОРИСТАННЯ АБСОРБЦІЙНОЇ БРОМИСТОЛІТІЄВОЇ ХОЛОДИЛЬНОЇ МАШИНИ В КОМБІНОВАНІЙ СИСТЕМІ ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ ГАЗОТУРБІННОЇ УСТАНОВКИ

The results of calculation of two stage gas turbine unit intake air cooling processes with previous cooling by absorption lithium-bromide chiller and deep cooling by ejector chiller are presented. The efficiency of the use of absorption lithium-bromide chiller cooling potential for changeable heat loads is analyzed. A scheme of cooling system with accumulating of surplus absorption lithium-bromide chiller cooling potential during decreased heat loads and its spending at increased heat loads has been proposed.

ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ ГТУ З УРАХУВАННЯМ КЛІМАТИЧНИХ ОСОБЛИВОСТЕЙ ЕКСПЛУАТАЦІЇ

Cooling the air at the inlet of gas turbine units by utilizing the exhaust gas waste heat in the combined absorption-ejector chiller with absorption lithium-bromide chiller as a gas turbine unit and refrigerant ejector chiller as a low temperature cooling stage has been analyzed for changeable climatic conditions. The climatic peculiarities of ambient air cooling processes consisting in time removing of maximal values of ambient air temperature and air cooler heat load have been investigated. Taking this into account the current heat loads on the two-stage gas turbine unit intake air cooler were analyzed in comparison with designed installed cooling capacity of absorption-ejector chiller, i.e. in comparison with designed heat load on the two-stage gas turbine unit intake air cooler. The lack and surplus of designed installed cooling capacity of absorption-ejector chiller was calculated. The reserves of increasing the fuel efficiency of gas turbine units by intake air deep cooling taking into account the mentioned above climatic peculiarities of air cooling processes were revealed. A combined absorption-ejector chiller with absorption lithium-bromide chiller as gas turbine unit intake air high temperature cooling stage and refrigerant ejector chiller with condenser cooled by absorption chiller as turbine intake air low temperature cooling stage has been proposed for turbine intake air deep cooling at maximal values of ambient air temperature and during decreased air cooler heat loads. So as the coefficient of performance of refrigerant ejector chiller is much lower compared with its value for absorption lithium-bromide chiller the efforts were aimed to increase the first one. Such a gas turbine unit intake air cooling system with combined absorption-ejector chiller provides increasing of its coefficient of performance due to refrigerant ejector chiller condenser cooling by absorption chiller and increasing of ejector chiller coefficient of performance as a result. The realization of gas turbine unit intake air deep cooling provides the maximal annual fuel saving for site climatic performance conditions.

ОТРИМАННЯ КОНДЕНСАТУ ПРИ ОХОЛОДЖЕННІ ПОВІТРЯ НА ВХОДІ ГТУ

A possibility of producing a condensate during condensing a steam in two stages cooling of cyclic air at the inlet of GTU by waste heat recovery absorption lithium bromide chiller and refrigerant ejector chiller utilizing the heat of exhaust gases was investigated. The dependence of quantity of condensate, dropped in the stage of previous air cooling at the inlet of GTU by chilled water from absorption lithium bromide chiller and in the stage of deep cooling by refrigerant ejector chiller, from heat load distribution between the stages has been analyzed. The results of calculations of dropped condensate quantity for climatic conditions of the south of Ukraine are presented.

СТУПІНЧАСТЕ ОХОЛОДЖЕННЯ ПРИТОЧНОГО ПОВІТРЯ МАШИННОГО ВІДДІЛЕННЯ АВТОНОМНОЇ ЕЛЕКТРОСТАНЦІЇ

Cooling of intake air for integrated electrical station engine room traditionally – by directing to air coolers of a coolant (water) from absorption lithium-bromide chiller and also deep cooling of the air by using a coolant with lower temperature received in combined two-stage chiller has been analyzed. The parameters of the air being cooled in the air coolers with various approaches of heat humidity treatment were determined.