The Experts below are selected from a list of 3915 Experts worldwide ranked by ideXlab platform
Vaibhav Jain - One of the best experts on this subject based on the ideXlab platform.
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comparative performance study and advanced exergy analysis of novel vapor compression absorption integRated refrigeration system
Energy Conversion and Management, 2018Co-Authors: Vaibhav Jain, Gulshan Sachdeva, Surendra Singh KachhwahaAbstract:Abstract In present work, a novel configuration of vapor compression-absorption integRated refrigeration system (VCAIRS) is analyzed. Unlike previous vapor compression-absorption cascaded refrigeration system (VCACRS), proposed configuration works at lower generator temperature of 60 °C. Thus, allowing the use of low grade waste heat for its operation. The performance of VCAIRS is also compared with the equivalent vapor compression refrigeration system (VCRS) and VCACRS for the same cooling capacity of 100 kW. The comparative study result shows that electrical energy requirement in VCAIRS is 21.4% more as compared to VCACRS but it is still 63% less as compared to the equivalent VCRS. Further, the second law efficiency of VCAIRS, VCACRS and VCRS are determined to be 27.9%, 32.7% and 18.8%, respectively. Thus, both the VCAIRS and VCACRS are energy and exergy efficient configurations; but, VCACRS results in more energy efficient cooling technology in the foreseeable future as it utilizes heat at lower generator temperature as compared to VCACRS. After the comparative performance study, the exergetic performance of VCAIRS is further explored based on the coefficient of structural bonds (CSB) and advanced exergy analysis methods. Highest CSB of 4.39 is obtained for high pressure solution heat exchanger but its overall contribution in total Irreversibility Rate is merely 0.2%; whereas, the highest contribution of 17.4% in total Irreversibility Rate is by compressor 1 but CSB value computed for it is merely 1.73. Further, advance exergy analysis results show that 35.2% of total Irreversibility Rate of VCAIRS can be avoided by improving the efficiency parameter of components of system.
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thermo economic and environmental analyses based multi objective optimization of vapor compression absorption cascaded refrigeration system using nsga ii technique
Energy Conversion and Management, 2016Co-Authors: Vaibhav Jain, Gulshan Sachdeva, Surendra Singh Kachhwaha, Bhavesh PatelAbstract:Abstract Present work optimizes the performance of 170 kW vapor compression–absorption cascaded refrigeration system (VCACRS) based on combined thermodynamic, economic and environmental parameters using Non-dominated Sort Genetic Algorithm-II (NSGA-II) technique. Two objective functions including the total Irreversibility Rate (as a thermodynamic criterion) and the total product cost (as an economic criterion) of the system are considered simultaneously for multi-objective optimization of VCACRS. The capital and maintenance costs of the system components, the operational cost, and the penalty cost due to CO 2 emission are included in the total product cost of the system. Three optimized systems including a single-objective thermodynamic optimized, a single-objective economic optimized and a multi-objective optimized are analyzed and compared. The results showed that the multi-objective design considers the combined thermodynamic and total product cost criteria better than the two individual single-objective thermodynamic and total product cost optimized designs.
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energy exergy economic and environmental 4e analyses based comparative performance study and optimization of vapor compression absorption integRated refrigeration system
Energy, 2015Co-Authors: Vaibhav Jain, Gulshan Sachdeva, Surendra Singh KachhwahaAbstract:Present work compares the performance of commercially available 170 kW vapor compression chiller with equivalent three configurations (parallel, series and combined series-parallel) of VCAIRS (vapor compression-absorption integRated refrigeration system) based on combined energy, exergy, economic and environmental (4E) analyses. Parallel, series and combined series-parallel configurations reduces the energy (electricity) consumption in the compressor by 50%, 76.8% and 88.3% respectively and consequently, reduce the significant amount of CO2 emission. Comparative exegetic analysis based on modified Gouy–Stodola law was performed which predicted higher Irreversibility Rate as compared to conventional approach. The thermoeconomic study shows that annual cost of the plant operation is 13.8%, 20.9% and 24.7% less for parallel, series and combined series-parallel configurations respectively as compared to equivalent VCRS (vapor compression refrigeration system) and after optimization, the same is further reduced by 8.1%, 8.5% and 4.7% respectively from the base value.
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Thermodynamic modelling and parametric study of a low temperature vapour compression-absorption system based on modified Gouy-Stodola equation
Energy, 2015Co-Authors: Vaibhav Jain, Gulshan Sachdeva, Surendra Singh KachhwahaAbstract:Present paper thermodynamically analyses a VCAS (vapour compression-absorption system) with carbon dioxide (compression section) and ammonia-water (absorption section) as refrigerants and determines the optimal condensing temperature of cascade condenser using modified Gouy-Stodola equation. The optimum cascade condenser temperature is found to be −13 °C for 175 kW refrigeration capacity at an evaporator temperature of −45 °C and condenser temperature of 35 °C. The optimum cascade condenser temperature maximises the overall COP, rational efficiency and minimises the total Irreversibility Rate of the VCAS system. The value of optimum condensing temperature and its corresponding maximum COP, and minimum Irreversibility Rate are discussed for a wide range of operating conditions. Further, a comparative study of TSVCS (two stage vapour compression system) used for low temperature refrigeration applications with VCAS shows that at design point, primary energy consumption is reduced by 60.6% and electrical COP is improved by 153.6% in VCAS as compared to conventional TSVCS. But the total Irreversibility Rate of VCAS is 38.4% higher than the TSVCS due to the use of low grade energy in vapour absorption system and hence the rational efficiency of VCAS is 14% low.
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thermodynamic performance analysis of a vapor compression absorption cascaded refrigeration system
Energy Conversion and Management, 2013Co-Authors: Vaibhav Jain, Surendra Singh Kachhwaha, Gulshan SachdevaAbstract:Abstract In the present study, a thermodynamic model for cascaded vapor compression–absorption system (CVCAS) has been developed which consists of a vapor compression refrigeration system (VCRS) coupled with single effect vapor absorption refrigeration system (VARS). Based on first and second laws, a comparative performance analysis of CVCAS and an independent VCRS has been carried out for a design capacity of 66.67 kW. The results show that the electric power consumption in CVCAS is reduced by 61% and COP of compression section is improved by 155% with respect to the corresponding values pertaining to a conventional VCRS. However there is a trade-off between these parameters and the rational efficiency which is found to decrease to half of that for a VCRS. The effect of various operating parameters, i.e., superheating, subcooling, cooling capacity, inlet temperature and the product of effectiveness and heat capacitance of external fluids are extensively studied on the COP, total Irreversibility and rational efficiency of the CVCAS. Besides, the performance of environment friendly refrigerants such as R410A, R407C and R134A is found to be almost at par with that of R22. Hence, all the alternative refrigerants selected herein can serve as potential substitutes for R22. Furthermore, it has been found that reducing the Irreversibility Rate of the condenser by one unit due to decrease in condenser temperature depicted approximately 3.8 times greater reduction in the total Irreversibility Rate of the CVCAS, whereas unit reduction in the evaporator’s Irreversibility Rate due to increase in evaporator temperature reduced total Irreversibility Rate by 3.4 times for the same system. Since the changes in the inlet temperatures of external fluid in the condenser and the evaporator contribute significant changes in system’s overall Irreversibility, due consideration is required in condenser and evaporator temperatures to improve the system performance.
Gulshan Sachdeva - One of the best experts on this subject based on the ideXlab platform.
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comparative performance study and advanced exergy analysis of novel vapor compression absorption integRated refrigeration system
Energy Conversion and Management, 2018Co-Authors: Vaibhav Jain, Gulshan Sachdeva, Surendra Singh KachhwahaAbstract:Abstract In present work, a novel configuration of vapor compression-absorption integRated refrigeration system (VCAIRS) is analyzed. Unlike previous vapor compression-absorption cascaded refrigeration system (VCACRS), proposed configuration works at lower generator temperature of 60 °C. Thus, allowing the use of low grade waste heat for its operation. The performance of VCAIRS is also compared with the equivalent vapor compression refrigeration system (VCRS) and VCACRS for the same cooling capacity of 100 kW. The comparative study result shows that electrical energy requirement in VCAIRS is 21.4% more as compared to VCACRS but it is still 63% less as compared to the equivalent VCRS. Further, the second law efficiency of VCAIRS, VCACRS and VCRS are determined to be 27.9%, 32.7% and 18.8%, respectively. Thus, both the VCAIRS and VCACRS are energy and exergy efficient configurations; but, VCACRS results in more energy efficient cooling technology in the foreseeable future as it utilizes heat at lower generator temperature as compared to VCACRS. After the comparative performance study, the exergetic performance of VCAIRS is further explored based on the coefficient of structural bonds (CSB) and advanced exergy analysis methods. Highest CSB of 4.39 is obtained for high pressure solution heat exchanger but its overall contribution in total Irreversibility Rate is merely 0.2%; whereas, the highest contribution of 17.4% in total Irreversibility Rate is by compressor 1 but CSB value computed for it is merely 1.73. Further, advance exergy analysis results show that 35.2% of total Irreversibility Rate of VCAIRS can be avoided by improving the efficiency parameter of components of system.
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thermo economic and environmental analyses based multi objective optimization of vapor compression absorption cascaded refrigeration system using nsga ii technique
Energy Conversion and Management, 2016Co-Authors: Vaibhav Jain, Gulshan Sachdeva, Surendra Singh Kachhwaha, Bhavesh PatelAbstract:Abstract Present work optimizes the performance of 170 kW vapor compression–absorption cascaded refrigeration system (VCACRS) based on combined thermodynamic, economic and environmental parameters using Non-dominated Sort Genetic Algorithm-II (NSGA-II) technique. Two objective functions including the total Irreversibility Rate (as a thermodynamic criterion) and the total product cost (as an economic criterion) of the system are considered simultaneously for multi-objective optimization of VCACRS. The capital and maintenance costs of the system components, the operational cost, and the penalty cost due to CO 2 emission are included in the total product cost of the system. Three optimized systems including a single-objective thermodynamic optimized, a single-objective economic optimized and a multi-objective optimized are analyzed and compared. The results showed that the multi-objective design considers the combined thermodynamic and total product cost criteria better than the two individual single-objective thermodynamic and total product cost optimized designs.
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energy exergy economic and environmental 4e analyses based comparative performance study and optimization of vapor compression absorption integRated refrigeration system
Energy, 2015Co-Authors: Vaibhav Jain, Gulshan Sachdeva, Surendra Singh KachhwahaAbstract:Present work compares the performance of commercially available 170 kW vapor compression chiller with equivalent three configurations (parallel, series and combined series-parallel) of VCAIRS (vapor compression-absorption integRated refrigeration system) based on combined energy, exergy, economic and environmental (4E) analyses. Parallel, series and combined series-parallel configurations reduces the energy (electricity) consumption in the compressor by 50%, 76.8% and 88.3% respectively and consequently, reduce the significant amount of CO2 emission. Comparative exegetic analysis based on modified Gouy–Stodola law was performed which predicted higher Irreversibility Rate as compared to conventional approach. The thermoeconomic study shows that annual cost of the plant operation is 13.8%, 20.9% and 24.7% less for parallel, series and combined series-parallel configurations respectively as compared to equivalent VCRS (vapor compression refrigeration system) and after optimization, the same is further reduced by 8.1%, 8.5% and 4.7% respectively from the base value.
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Thermodynamic modelling and parametric study of a low temperature vapour compression-absorption system based on modified Gouy-Stodola equation
Energy, 2015Co-Authors: Vaibhav Jain, Gulshan Sachdeva, Surendra Singh KachhwahaAbstract:Present paper thermodynamically analyses a VCAS (vapour compression-absorption system) with carbon dioxide (compression section) and ammonia-water (absorption section) as refrigerants and determines the optimal condensing temperature of cascade condenser using modified Gouy-Stodola equation. The optimum cascade condenser temperature is found to be −13 °C for 175 kW refrigeration capacity at an evaporator temperature of −45 °C and condenser temperature of 35 °C. The optimum cascade condenser temperature maximises the overall COP, rational efficiency and minimises the total Irreversibility Rate of the VCAS system. The value of optimum condensing temperature and its corresponding maximum COP, and minimum Irreversibility Rate are discussed for a wide range of operating conditions. Further, a comparative study of TSVCS (two stage vapour compression system) used for low temperature refrigeration applications with VCAS shows that at design point, primary energy consumption is reduced by 60.6% and electrical COP is improved by 153.6% in VCAS as compared to conventional TSVCS. But the total Irreversibility Rate of VCAS is 38.4% higher than the TSVCS due to the use of low grade energy in vapour absorption system and hence the rational efficiency of VCAS is 14% low.
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thermodynamic performance analysis of a vapor compression absorption cascaded refrigeration system
Energy Conversion and Management, 2013Co-Authors: Vaibhav Jain, Surendra Singh Kachhwaha, Gulshan SachdevaAbstract:Abstract In the present study, a thermodynamic model for cascaded vapor compression–absorption system (CVCAS) has been developed which consists of a vapor compression refrigeration system (VCRS) coupled with single effect vapor absorption refrigeration system (VARS). Based on first and second laws, a comparative performance analysis of CVCAS and an independent VCRS has been carried out for a design capacity of 66.67 kW. The results show that the electric power consumption in CVCAS is reduced by 61% and COP of compression section is improved by 155% with respect to the corresponding values pertaining to a conventional VCRS. However there is a trade-off between these parameters and the rational efficiency which is found to decrease to half of that for a VCRS. The effect of various operating parameters, i.e., superheating, subcooling, cooling capacity, inlet temperature and the product of effectiveness and heat capacitance of external fluids are extensively studied on the COP, total Irreversibility and rational efficiency of the CVCAS. Besides, the performance of environment friendly refrigerants such as R410A, R407C and R134A is found to be almost at par with that of R22. Hence, all the alternative refrigerants selected herein can serve as potential substitutes for R22. Furthermore, it has been found that reducing the Irreversibility Rate of the condenser by one unit due to decrease in condenser temperature depicted approximately 3.8 times greater reduction in the total Irreversibility Rate of the CVCAS, whereas unit reduction in the evaporator’s Irreversibility Rate due to increase in evaporator temperature reduced total Irreversibility Rate by 3.4 times for the same system. Since the changes in the inlet temperatures of external fluid in the condenser and the evaporator contribute significant changes in system’s overall Irreversibility, due consideration is required in condenser and evaporator temperatures to improve the system performance.
Surendra Singh Kachhwaha - One of the best experts on this subject based on the ideXlab platform.
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comparative performance study and advanced exergy analysis of novel vapor compression absorption integRated refrigeration system
Energy Conversion and Management, 2018Co-Authors: Vaibhav Jain, Gulshan Sachdeva, Surendra Singh KachhwahaAbstract:Abstract In present work, a novel configuration of vapor compression-absorption integRated refrigeration system (VCAIRS) is analyzed. Unlike previous vapor compression-absorption cascaded refrigeration system (VCACRS), proposed configuration works at lower generator temperature of 60 °C. Thus, allowing the use of low grade waste heat for its operation. The performance of VCAIRS is also compared with the equivalent vapor compression refrigeration system (VCRS) and VCACRS for the same cooling capacity of 100 kW. The comparative study result shows that electrical energy requirement in VCAIRS is 21.4% more as compared to VCACRS but it is still 63% less as compared to the equivalent VCRS. Further, the second law efficiency of VCAIRS, VCACRS and VCRS are determined to be 27.9%, 32.7% and 18.8%, respectively. Thus, both the VCAIRS and VCACRS are energy and exergy efficient configurations; but, VCACRS results in more energy efficient cooling technology in the foreseeable future as it utilizes heat at lower generator temperature as compared to VCACRS. After the comparative performance study, the exergetic performance of VCAIRS is further explored based on the coefficient of structural bonds (CSB) and advanced exergy analysis methods. Highest CSB of 4.39 is obtained for high pressure solution heat exchanger but its overall contribution in total Irreversibility Rate is merely 0.2%; whereas, the highest contribution of 17.4% in total Irreversibility Rate is by compressor 1 but CSB value computed for it is merely 1.73. Further, advance exergy analysis results show that 35.2% of total Irreversibility Rate of VCAIRS can be avoided by improving the efficiency parameter of components of system.
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thermo economic and environmental analyses based multi objective optimization of vapor compression absorption cascaded refrigeration system using nsga ii technique
Energy Conversion and Management, 2016Co-Authors: Vaibhav Jain, Gulshan Sachdeva, Surendra Singh Kachhwaha, Bhavesh PatelAbstract:Abstract Present work optimizes the performance of 170 kW vapor compression–absorption cascaded refrigeration system (VCACRS) based on combined thermodynamic, economic and environmental parameters using Non-dominated Sort Genetic Algorithm-II (NSGA-II) technique. Two objective functions including the total Irreversibility Rate (as a thermodynamic criterion) and the total product cost (as an economic criterion) of the system are considered simultaneously for multi-objective optimization of VCACRS. The capital and maintenance costs of the system components, the operational cost, and the penalty cost due to CO 2 emission are included in the total product cost of the system. Three optimized systems including a single-objective thermodynamic optimized, a single-objective economic optimized and a multi-objective optimized are analyzed and compared. The results showed that the multi-objective design considers the combined thermodynamic and total product cost criteria better than the two individual single-objective thermodynamic and total product cost optimized designs.
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energy exergy economic and environmental 4e analyses based comparative performance study and optimization of vapor compression absorption integRated refrigeration system
Energy, 2015Co-Authors: Vaibhav Jain, Gulshan Sachdeva, Surendra Singh KachhwahaAbstract:Present work compares the performance of commercially available 170 kW vapor compression chiller with equivalent three configurations (parallel, series and combined series-parallel) of VCAIRS (vapor compression-absorption integRated refrigeration system) based on combined energy, exergy, economic and environmental (4E) analyses. Parallel, series and combined series-parallel configurations reduces the energy (electricity) consumption in the compressor by 50%, 76.8% and 88.3% respectively and consequently, reduce the significant amount of CO2 emission. Comparative exegetic analysis based on modified Gouy–Stodola law was performed which predicted higher Irreversibility Rate as compared to conventional approach. The thermoeconomic study shows that annual cost of the plant operation is 13.8%, 20.9% and 24.7% less for parallel, series and combined series-parallel configurations respectively as compared to equivalent VCRS (vapor compression refrigeration system) and after optimization, the same is further reduced by 8.1%, 8.5% and 4.7% respectively from the base value.
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Thermodynamic modelling and parametric study of a low temperature vapour compression-absorption system based on modified Gouy-Stodola equation
Energy, 2015Co-Authors: Vaibhav Jain, Gulshan Sachdeva, Surendra Singh KachhwahaAbstract:Present paper thermodynamically analyses a VCAS (vapour compression-absorption system) with carbon dioxide (compression section) and ammonia-water (absorption section) as refrigerants and determines the optimal condensing temperature of cascade condenser using modified Gouy-Stodola equation. The optimum cascade condenser temperature is found to be −13 °C for 175 kW refrigeration capacity at an evaporator temperature of −45 °C and condenser temperature of 35 °C. The optimum cascade condenser temperature maximises the overall COP, rational efficiency and minimises the total Irreversibility Rate of the VCAS system. The value of optimum condensing temperature and its corresponding maximum COP, and minimum Irreversibility Rate are discussed for a wide range of operating conditions. Further, a comparative study of TSVCS (two stage vapour compression system) used for low temperature refrigeration applications with VCAS shows that at design point, primary energy consumption is reduced by 60.6% and electrical COP is improved by 153.6% in VCAS as compared to conventional TSVCS. But the total Irreversibility Rate of VCAS is 38.4% higher than the TSVCS due to the use of low grade energy in vapour absorption system and hence the rational efficiency of VCAS is 14% low.
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thermodynamic performance analysis of a vapor compression absorption cascaded refrigeration system
Energy Conversion and Management, 2013Co-Authors: Vaibhav Jain, Surendra Singh Kachhwaha, Gulshan SachdevaAbstract:Abstract In the present study, a thermodynamic model for cascaded vapor compression–absorption system (CVCAS) has been developed which consists of a vapor compression refrigeration system (VCRS) coupled with single effect vapor absorption refrigeration system (VARS). Based on first and second laws, a comparative performance analysis of CVCAS and an independent VCRS has been carried out for a design capacity of 66.67 kW. The results show that the electric power consumption in CVCAS is reduced by 61% and COP of compression section is improved by 155% with respect to the corresponding values pertaining to a conventional VCRS. However there is a trade-off between these parameters and the rational efficiency which is found to decrease to half of that for a VCRS. The effect of various operating parameters, i.e., superheating, subcooling, cooling capacity, inlet temperature and the product of effectiveness and heat capacitance of external fluids are extensively studied on the COP, total Irreversibility and rational efficiency of the CVCAS. Besides, the performance of environment friendly refrigerants such as R410A, R407C and R134A is found to be almost at par with that of R22. Hence, all the alternative refrigerants selected herein can serve as potential substitutes for R22. Furthermore, it has been found that reducing the Irreversibility Rate of the condenser by one unit due to decrease in condenser temperature depicted approximately 3.8 times greater reduction in the total Irreversibility Rate of the CVCAS, whereas unit reduction in the evaporator’s Irreversibility Rate due to increase in evaporator temperature reduced total Irreversibility Rate by 3.4 times for the same system. Since the changes in the inlet temperatures of external fluid in the condenser and the evaporator contribute significant changes in system’s overall Irreversibility, due consideration is required in condenser and evaporator temperatures to improve the system performance.
Bilal Zemher - One of the best experts on this subject based on the ideXlab platform.
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effect of saturation temperature on the performance of a vapour compression refrigeration cycle working on different refrigerants using exergy method
International Journal of Energy Research, 2006Co-Authors: Mehmet Kopac, Bilal ZemherAbstract:In this study, the behaviour of a vapour-compression refrigeration cycle, for different refrigerants such as NH3, R-12, R-22 and HFC-134a was investigated using the exergy method. The cooling load of the plant and the saturation-temperature of the cold chamber were held constant, whereas the saturation-temperatures of the evaporator and the condenser were varied from 303 to 313 K and 258 to 248 K, respectively. The Irreversibility Rates (or exergy destruction Rates) of sub-regions for the whole cycle, using energy and exergy analysis, were determined for each refrigerant. The effects of changes in the saturation-temperature in the condenser and evaporator on the Irreversibility Rate of the cycle were obtained for each refrigerant. The relations between the total Irreversibility Rate of the plant and the Irreversibility Rate of the condenser and the evaporator were determined for different values of saturation temperatures of the condenser and the evaporator. The COP of the cycle and the rational efficiency were determined for each of the refrigerants and compared with each other. Among the refrigerants used, R-12 was found to be the most economical refrigerant as compared with the others. Copyright © 2005 John Wiley & Sons, Ltd.
Bhavesh Patel - One of the best experts on this subject based on the ideXlab platform.
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thermo economic and environmental analyses based multi objective optimization of vapor compression absorption cascaded refrigeration system using nsga ii technique
Energy Conversion and Management, 2016Co-Authors: Vaibhav Jain, Gulshan Sachdeva, Surendra Singh Kachhwaha, Bhavesh PatelAbstract:Abstract Present work optimizes the performance of 170 kW vapor compression–absorption cascaded refrigeration system (VCACRS) based on combined thermodynamic, economic and environmental parameters using Non-dominated Sort Genetic Algorithm-II (NSGA-II) technique. Two objective functions including the total Irreversibility Rate (as a thermodynamic criterion) and the total product cost (as an economic criterion) of the system are considered simultaneously for multi-objective optimization of VCACRS. The capital and maintenance costs of the system components, the operational cost, and the penalty cost due to CO 2 emission are included in the total product cost of the system. Three optimized systems including a single-objective thermodynamic optimized, a single-objective economic optimized and a multi-objective optimized are analyzed and compared. The results showed that the multi-objective design considers the combined thermodynamic and total product cost criteria better than the two individual single-objective thermodynamic and total product cost optimized designs.
