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Jagdev Singh - One of the best experts on this subject based on the ideXlab platform.
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ann approach for irreversibility analysis of vapor Compression Refrigeration System using r134a lpg blend as replacement of r134a
Journal of Thermal Analysis and Calorimetry, 2019Co-Authors: Jatinder Gill, Jagdev Singh, Olayinka S Ohunakin, D S AdelekanAbstract:This paper experimentally evaluated the irreversibility in the components (compressor, condenser, capillary tube, and evaporator) of the vapor Compression Refrigeration System (VCRS) using R134a/LPG refrigerant as a replacement for R134a. For this aim, different tests were conducted for various evaporator and condenser temperatures under controlled surrounding conditions. The results reported that the irreversibilities in the components of VCRS using R134a/LPG blend were found lesser than irreversibilities in the components of VCRS using R134a under similar experimental conditions. Artificial neural network (ANN) models were developed to predict the second law of efficiency and total irreversibility of the Refrigeration System. ANN and ANFIS model predictions were also compared with experimental results and an absolute fraction of variance in range of 0.980–0.994 and 0.951–0.977, root-mean-square error in the range of 0.1636–0.2387 and 0.2501–0.4542 and mean absolute percentage error in the range of 0.159–0.572 and 0.308–0.931%, respectively, were estimated. The outcomes suggested that ANN model shows better statistical prediction than ANFIS model.
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Component-wise exergy and energy analysis of vapor Compression Refrigeration System using mixture of R134a and LPG as refrigerant
Heat and Mass Transfer, 2018Co-Authors: Jatinder Gill, Jagdev SinghAbstract:In this work, the experimental examination was carried out using a mixture of R134a and LPG refrigerant (consisting of R134a and LPG in a proportion of 28:72 by weight) as a replacement for R134a in a vapor Compression Refrigeration System. Exergy and energy tests were carried out at different evaporator and condenser temperatures with controlled environmental conditions. The results showed that the exergy destruction in the compressor, condenser, evaporator, and a capillary tube of the R134a / LPG Refrigeration System was found lower by approximately 11.13–3.41%, 2.24–3.43%, 12.02–13.47% and 1.54–5.61% respectively. The compressor exhibits the highest level of destruction, accompanied by a condenser, an evaporator and a capillary tube in Refrigeration Systems. The Refrigeration capacity, COP and power consumption of the compressor of the R134a /LPG Refrigeration System were detected higher and lower compared to the R134a Refrigeration System by about 7.04–11.41%, 15.1–17.82%, and 3.83–8.08% respectively. Also, the miscibility of R134a and LPG blend with mineral oil discovered good. The R134a and LPG refrigerant mixture proposed in this study perform superior to R134a from component-wise exergy and energy analyses under similar experimental conditions.
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energy analysis of vapor Compression Refrigeration System using mixture of r134a and lpg as refrigerant
International Journal of Refrigeration-revue Internationale Du Froid, 2017Co-Authors: Jatinder Gill, Jagdev SinghAbstract:Abstract According to Kyoto protocol, R134a must be phased out soon due to its high global warming potential of 1430. In this work, an experimental investigation is carried out with R134a and LPG refrigerant mixture (composed of R134a and LPG in the ratio of 28:72 by weight) as an alternative to R134a in a vapor Compression Refrigeration System. Performance tests were performed under different evaporator and condenser temperatures with controlled ambient conditions. The results showed that the R134a and LPG refrigerant mixture has a higher coefficient of performance and lower compressor discharge temperature and pull down time as compared to R134a by about 15.1–17.82%, 2.10–13.86% and 1.01–5.90% respectively. Furthermore, the miscibility of R134a/LPG with mineral oil as a lubricant was also found good. In conclusion, the mixing refrigerant R134a/LPG proposed in this study seems to be an appropriate long-term candidate to replace R134a as a new generation refrigerant of VCRS, because of its well environmentally acceptable properties and its favorable Refrigeration performances.
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energetic and exergetic performance analysis of the vapor Compression Refrigeration System using adaptive neuro fuzzy inference System approach
Experimental Thermal and Fluid Science, 2017Co-Authors: Jatinder Gill, Jagdev SinghAbstract:Abstract According to Kyoto protocol R134a must be phased out soon due to its high global warming potential of 1430. In this work, an experimental investigation has made with R134a and LPG refrigerant mixture (composed of R134a and LPG in the ratio of 28:72 by weight) as an alternative to R134a in a vapor Compression Refrigeration System. Performance tests performed under different evaporator and condenser temperatures with controlled ambient conditions. The results showed that the R134a and LPG refrigerant mixture has higher values of coefficient of performance and exergy efficiency as compared to R134a by about 10.57–15.28% and 6.60–11.40%, respectively. The applicability of adaptive neuro-fuzzy inference System (ANFIS) to predict COP, Total Exergy destruction and Exergy efficiency of R134a/LPG System also investigated. For this aim, some of the experimental data utilized for training, an ANFIS model for the System developed. The ANFIS predictions agreed well with the experimental results with an absolute fraction of variance (R 2 ) in the range of 0.994–0.998, a root mean square error (RMSE) in the range of 0.0018–0.1907 and mean absolute percentage error (MAPE) in the range of 0.103–0.897%. The results suggest that the ANFIS approach can be used successfully for predicting the performance of vapor Compression Refrigeration Systems.
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performance analysis of vapor Compression Refrigeration System using an adaptive neuro fuzzy inference System
International Journal of Refrigeration-revue Internationale Du Froid, 2017Co-Authors: Jatinder Gill, Jagdev SinghAbstract:Abstract In this work, an experimental investigation is carried out with R134a and LPG refrigerant mixture (composed of R134a and LPG in the ratio of 28:72 by weight) as an alternative to R134a in a vapor Compression Refrigeration System. Performance tests were performed with different evaporator temperatures under controlled ambient conditions. The results showed that the R134a/LPG mixture has a higher coefficient of performance (COP) than R134a by about 15.28% in the studied range. The applicability of adaptive neuro-fuzzy inference System (ANFIS) to predict the COP of R134a/LPG System was also investigated. An ANFIS model for the System was developed. The comparison of statistical analysis of mathematical and ANFIS model predictions respectively in terms of the absolute fraction of variance (0.982 and 0.994), the root mean square error (0.0056 and 0.0050) and the mean absolute percentage error (0.286% and 0.217%) showed that ANFIS model gave the better statistical prediction efficiency.
Jatinder Gill - One of the best experts on this subject based on the ideXlab platform.
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ann approach for irreversibility analysis of vapor Compression Refrigeration System using r134a lpg blend as replacement of r134a
Journal of Thermal Analysis and Calorimetry, 2019Co-Authors: Jatinder Gill, Jagdev Singh, Olayinka S Ohunakin, D S AdelekanAbstract:This paper experimentally evaluated the irreversibility in the components (compressor, condenser, capillary tube, and evaporator) of the vapor Compression Refrigeration System (VCRS) using R134a/LPG refrigerant as a replacement for R134a. For this aim, different tests were conducted for various evaporator and condenser temperatures under controlled surrounding conditions. The results reported that the irreversibilities in the components of VCRS using R134a/LPG blend were found lesser than irreversibilities in the components of VCRS using R134a under similar experimental conditions. Artificial neural network (ANN) models were developed to predict the second law of efficiency and total irreversibility of the Refrigeration System. ANN and ANFIS model predictions were also compared with experimental results and an absolute fraction of variance in range of 0.980–0.994 and 0.951–0.977, root-mean-square error in the range of 0.1636–0.2387 and 0.2501–0.4542 and mean absolute percentage error in the range of 0.159–0.572 and 0.308–0.931%, respectively, were estimated. The outcomes suggested that ANN model shows better statistical prediction than ANFIS model.
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Component-wise exergy and energy analysis of vapor Compression Refrigeration System using mixture of R134a and LPG as refrigerant
Heat and Mass Transfer, 2018Co-Authors: Jatinder Gill, Jagdev SinghAbstract:In this work, the experimental examination was carried out using a mixture of R134a and LPG refrigerant (consisting of R134a and LPG in a proportion of 28:72 by weight) as a replacement for R134a in a vapor Compression Refrigeration System. Exergy and energy tests were carried out at different evaporator and condenser temperatures with controlled environmental conditions. The results showed that the exergy destruction in the compressor, condenser, evaporator, and a capillary tube of the R134a / LPG Refrigeration System was found lower by approximately 11.13–3.41%, 2.24–3.43%, 12.02–13.47% and 1.54–5.61% respectively. The compressor exhibits the highest level of destruction, accompanied by a condenser, an evaporator and a capillary tube in Refrigeration Systems. The Refrigeration capacity, COP and power consumption of the compressor of the R134a /LPG Refrigeration System were detected higher and lower compared to the R134a Refrigeration System by about 7.04–11.41%, 15.1–17.82%, and 3.83–8.08% respectively. Also, the miscibility of R134a and LPG blend with mineral oil discovered good. The R134a and LPG refrigerant mixture proposed in this study perform superior to R134a from component-wise exergy and energy analyses under similar experimental conditions.
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energy analysis of vapor Compression Refrigeration System using mixture of r134a and lpg as refrigerant
International Journal of Refrigeration-revue Internationale Du Froid, 2017Co-Authors: Jatinder Gill, Jagdev SinghAbstract:Abstract According to Kyoto protocol, R134a must be phased out soon due to its high global warming potential of 1430. In this work, an experimental investigation is carried out with R134a and LPG refrigerant mixture (composed of R134a and LPG in the ratio of 28:72 by weight) as an alternative to R134a in a vapor Compression Refrigeration System. Performance tests were performed under different evaporator and condenser temperatures with controlled ambient conditions. The results showed that the R134a and LPG refrigerant mixture has a higher coefficient of performance and lower compressor discharge temperature and pull down time as compared to R134a by about 15.1–17.82%, 2.10–13.86% and 1.01–5.90% respectively. Furthermore, the miscibility of R134a/LPG with mineral oil as a lubricant was also found good. In conclusion, the mixing refrigerant R134a/LPG proposed in this study seems to be an appropriate long-term candidate to replace R134a as a new generation refrigerant of VCRS, because of its well environmentally acceptable properties and its favorable Refrigeration performances.
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energetic and exergetic performance analysis of the vapor Compression Refrigeration System using adaptive neuro fuzzy inference System approach
Experimental Thermal and Fluid Science, 2017Co-Authors: Jatinder Gill, Jagdev SinghAbstract:Abstract According to Kyoto protocol R134a must be phased out soon due to its high global warming potential of 1430. In this work, an experimental investigation has made with R134a and LPG refrigerant mixture (composed of R134a and LPG in the ratio of 28:72 by weight) as an alternative to R134a in a vapor Compression Refrigeration System. Performance tests performed under different evaporator and condenser temperatures with controlled ambient conditions. The results showed that the R134a and LPG refrigerant mixture has higher values of coefficient of performance and exergy efficiency as compared to R134a by about 10.57–15.28% and 6.60–11.40%, respectively. The applicability of adaptive neuro-fuzzy inference System (ANFIS) to predict COP, Total Exergy destruction and Exergy efficiency of R134a/LPG System also investigated. For this aim, some of the experimental data utilized for training, an ANFIS model for the System developed. The ANFIS predictions agreed well with the experimental results with an absolute fraction of variance (R 2 ) in the range of 0.994–0.998, a root mean square error (RMSE) in the range of 0.0018–0.1907 and mean absolute percentage error (MAPE) in the range of 0.103–0.897%. The results suggest that the ANFIS approach can be used successfully for predicting the performance of vapor Compression Refrigeration Systems.
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performance analysis of vapor Compression Refrigeration System using an adaptive neuro fuzzy inference System
International Journal of Refrigeration-revue Internationale Du Froid, 2017Co-Authors: Jatinder Gill, Jagdev SinghAbstract:Abstract In this work, an experimental investigation is carried out with R134a and LPG refrigerant mixture (composed of R134a and LPG in the ratio of 28:72 by weight) as an alternative to R134a in a vapor Compression Refrigeration System. Performance tests were performed with different evaporator temperatures under controlled ambient conditions. The results showed that the R134a/LPG mixture has a higher coefficient of performance (COP) than R134a by about 15.28% in the studied range. The applicability of adaptive neuro-fuzzy inference System (ANFIS) to predict the COP of R134a/LPG System was also investigated. An ANFIS model for the System was developed. The comparison of statistical analysis of mathematical and ANFIS model predictions respectively in terms of the absolute fraction of variance (0.982 and 0.994), the root mean square error (0.0056 and 0.0050) and the mean absolute percentage error (0.286% and 0.217%) showed that ANFIS model gave the better statistical prediction efficiency.
Hongguang Jin - One of the best experts on this subject based on the ideXlab platform.
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Thermodynamic performance optimization of the absorption-generation process in an absorption Refrigeration cycle
Energy Conversion and Management, 2016Co-Authors: Yi Chen, Wei Han, Hongguang JinAbstract:Abstract The absorption Refrigeration cycle is a basic cycle that establishes the Systems for utilizing mid-low temperature heat sources. A new thermal compressor model with a key parameter of boost pressure ratio is proposed to optimize the absorption-generation process. The ultimate generation pressure and boost pressure ratio are used to represent the potential and operating conditions of the thermal compressor, respectively. Using the proposed thermal compressor model, the operation mechanism and requirements of the absorption Refrigeration System and absorption-Compression Refrigeration System are elucidated. Furthermore, the two typical heat conversion Systems are optimized based on the thermal compressor model. The optimum boost pressure ratios of the absorption Refrigeration System and the absorption-Compression Refrigeration System are 0.5 and 0.75, respectively. For the absorption Refrigeration System, the optimum generation temperature is 125.31 °C at the cooling water temperature of 30 °C, which is obtained by simple thermodynamic calculation. The optimized thermodynamic performance of the absorption-Compression Refrigeration System is 16.7% higher than that of the conventional absorption Refrigeration System when the generation temperature is 100 °C. The thermal compressor model proposed in this paper is an effective method for simplifying the optimization of the thermodynamic Systems involving an absorption-generation process.
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analysis of an absorption absorption Compression Refrigeration System for heat sources with large temperature change
Energy Conversion and Management, 2016Co-Authors: Yi Chen, Wei Han, Hongguang JinAbstract:Abstract Absorption Refrigeration Systems are a promising way to reduce electricity consumption in the field of Refrigeration and cooling. To improve the thermal energy utilization performance of the absorption Refrigeration System, an absorption/absorption–Compression Refrigeration System with a large working range is proposed in this paper. The new System consists of a conventional single-effect absorption subcycle and an absorption–Compression Refrigeration subcycle, and they share the condenser, evaporator, absorber and some other relative components. The temperature of the waste gas exhausted from the System can be 35 °C lower than that of the waste gas from a traditional, single-effect absorption Refrigeration System. For the proposed System, the cooling capacity per unit mass of flue gas reaches 58.95 kJ kg −1 when the evaporation temperature is −15 °C, which is 28.21% higher than that of the single-effect absorption Refrigeration System. The exergy efficiency of the proposed System is as high as 25.94%. To indicate the direction of System optimization, the new System is further studied using a parametric analysis. The new absorption/absorption–Compression Refrigeration System provides a promising way to efficiently utilize heat sources with large temperature change or multiple heat sources with different temperatures.
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an absorption Compression Refrigeration System driven by a mid temperature heat source for low temperature applications
Energy, 2015Co-Authors: Yi Chen, Wei Han, Hongguang JinAbstract:An ammonia–water absorption Refrigeration System is a promising way to make use of waste heat to generate cooling energy for freezing applications. When the Refrigeration temperature is below −30 °C, the conventional absorption System cannot be adopted because its performance decreases dramatically. In this work, a totally heat-driven absorption–Compression Refrigeration System is proposed to produce cooling energy at temperatures of −40 °C to −55 °C. The proposed System comprises a heat-driven power generation subSystem using an ammonia–water mixture as the working fluid and an absorption–Compression Refrigeration subSystem. Simulation results showed that the coefficient of performance and the cooling capacity per unit mass of flue gas reach 0.357 and 84.18 kJ kg−1, respectively. The results of a process energy analysis showed that the cycle coupling configuration of the proposed System enhances its energy cascade utilization. Furthermore, the energy saving mechanism of the proposed System was elucidated by means of an exergy analysis and a pinch point analysis. Finally, a more comprehensive comparison with a heat-driven double-stage Compression Refrigeration System was conducted to show the advantage of the proposed System. This work may provide a new way to produce low-temperature cooling energy by using a mid-temperature heat source.
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a new absorption Compression Refrigeration System using a mid temperature heat source for freezing application
Energy Procedia, 2015Co-Authors: Yi Chen, Wei Han, Liuli Sun, Hongguang JinAbstract:Abstract The use of an absorption Refrigeration System is a promising way to utilize waste heat from industrial processes. Ammonia–water absorption Refrigeration System is commonly used for freezing applications with temperatures lower than 0 °C. When the Refrigeration temperature is lower than -30 °C, the performance dramatically decreases. We proposed a new absorption–Compression Refrigeration System to produce cooling energy at -30 °C to -55 °C. The proposed System comprised three subSystems, namely, a power generation subSystem using an ammonia–water mixture as the working fluid, an ammonia–water absorption Refrigeration subSystem, and a CO 2 Compression Refrigeration subSystem. The System utilized the heat source in a cascade manner. The power subSystem converted the high-temperature portion of heat into power to drive the CO 2 Compression Refrigeration subSystem, thereby resulting in the generation of low-temperature cooling energy. The low-temperature portion of heat is converted into cooling energy to offer the heat sink of the CO 2 Compression Refrigeration subSystem. A simulation study was conducted, and results showed that the coefficient of performance of the proposed System was 0.277, which was approximately 50% higher than that of a conventional two-stage absorption Refrigeration System. This work may provide a new way to produce low-temperature cooling energy using mid-temperature heat source.
Yi Chen - One of the best experts on this subject based on the ideXlab platform.
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proposal and analysis of a novel heat driven absorption Compression Refrigeration System at low temperatures
Applied Energy, 2017Co-Authors: Yi ChenAbstract:Absorption Refrigeration Systems have been widely applied to utilize waste heat from industrial processes. In this work, a novel heat-driven absorption–Compression Refrigeration System is proposed to produce the cooling energy required to reach a temperature as low as −60°C. The proposed System is composed of three subSystems: a power generation subSystem using ammonia–water mixture working fluid, an ammonia–water absorption Refrigeration subSystem, and a CO2 Compression Refrigeration subSystem. The System utilizes the heat source using a cascade approach. A simulation study is conducted, and the results show that, when the evaporation temperature is −55°C, the cooling capacity per unit mass of flue gas and the coefficient of performance of the proposed System can reach 62.70kJkg−1 and 0.277, respectively. The effects of the power subSystem working fluid concentration, the turbine inlet pressure, the split fraction and the intermediate condensation temperature on the System’s performance are analyzed to provide guidance to the System design. Performance comparison shows that the proposed System has an outstanding adaptability, and its practical applications are also considered. This work may provide a new approach to producing low-temperature cooling energy using a mid-temperature heat source.
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Thermodynamic performance optimization of the absorption-generation process in an absorption Refrigeration cycle
Energy Conversion and Management, 2016Co-Authors: Yi Chen, Wei Han, Hongguang JinAbstract:Abstract The absorption Refrigeration cycle is a basic cycle that establishes the Systems for utilizing mid-low temperature heat sources. A new thermal compressor model with a key parameter of boost pressure ratio is proposed to optimize the absorption-generation process. The ultimate generation pressure and boost pressure ratio are used to represent the potential and operating conditions of the thermal compressor, respectively. Using the proposed thermal compressor model, the operation mechanism and requirements of the absorption Refrigeration System and absorption-Compression Refrigeration System are elucidated. Furthermore, the two typical heat conversion Systems are optimized based on the thermal compressor model. The optimum boost pressure ratios of the absorption Refrigeration System and the absorption-Compression Refrigeration System are 0.5 and 0.75, respectively. For the absorption Refrigeration System, the optimum generation temperature is 125.31 °C at the cooling water temperature of 30 °C, which is obtained by simple thermodynamic calculation. The optimized thermodynamic performance of the absorption-Compression Refrigeration System is 16.7% higher than that of the conventional absorption Refrigeration System when the generation temperature is 100 °C. The thermal compressor model proposed in this paper is an effective method for simplifying the optimization of the thermodynamic Systems involving an absorption-generation process.
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analysis of an absorption absorption Compression Refrigeration System for heat sources with large temperature change
Energy Conversion and Management, 2016Co-Authors: Yi Chen, Wei Han, Hongguang JinAbstract:Abstract Absorption Refrigeration Systems are a promising way to reduce electricity consumption in the field of Refrigeration and cooling. To improve the thermal energy utilization performance of the absorption Refrigeration System, an absorption/absorption–Compression Refrigeration System with a large working range is proposed in this paper. The new System consists of a conventional single-effect absorption subcycle and an absorption–Compression Refrigeration subcycle, and they share the condenser, evaporator, absorber and some other relative components. The temperature of the waste gas exhausted from the System can be 35 °C lower than that of the waste gas from a traditional, single-effect absorption Refrigeration System. For the proposed System, the cooling capacity per unit mass of flue gas reaches 58.95 kJ kg −1 when the evaporation temperature is −15 °C, which is 28.21% higher than that of the single-effect absorption Refrigeration System. The exergy efficiency of the proposed System is as high as 25.94%. To indicate the direction of System optimization, the new System is further studied using a parametric analysis. The new absorption/absorption–Compression Refrigeration System provides a promising way to efficiently utilize heat sources with large temperature change or multiple heat sources with different temperatures.
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an absorption Compression Refrigeration System driven by a mid temperature heat source for low temperature applications
Energy, 2015Co-Authors: Yi Chen, Wei Han, Hongguang JinAbstract:An ammonia–water absorption Refrigeration System is a promising way to make use of waste heat to generate cooling energy for freezing applications. When the Refrigeration temperature is below −30 °C, the conventional absorption System cannot be adopted because its performance decreases dramatically. In this work, a totally heat-driven absorption–Compression Refrigeration System is proposed to produce cooling energy at temperatures of −40 °C to −55 °C. The proposed System comprises a heat-driven power generation subSystem using an ammonia–water mixture as the working fluid and an absorption–Compression Refrigeration subSystem. Simulation results showed that the coefficient of performance and the cooling capacity per unit mass of flue gas reach 0.357 and 84.18 kJ kg−1, respectively. The results of a process energy analysis showed that the cycle coupling configuration of the proposed System enhances its energy cascade utilization. Furthermore, the energy saving mechanism of the proposed System was elucidated by means of an exergy analysis and a pinch point analysis. Finally, a more comprehensive comparison with a heat-driven double-stage Compression Refrigeration System was conducted to show the advantage of the proposed System. This work may provide a new way to produce low-temperature cooling energy by using a mid-temperature heat source.
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a new absorption Compression Refrigeration System using a mid temperature heat source for freezing application
Energy Procedia, 2015Co-Authors: Yi Chen, Wei Han, Liuli Sun, Hongguang JinAbstract:Abstract The use of an absorption Refrigeration System is a promising way to utilize waste heat from industrial processes. Ammonia–water absorption Refrigeration System is commonly used for freezing applications with temperatures lower than 0 °C. When the Refrigeration temperature is lower than -30 °C, the performance dramatically decreases. We proposed a new absorption–Compression Refrigeration System to produce cooling energy at -30 °C to -55 °C. The proposed System comprised three subSystems, namely, a power generation subSystem using an ammonia–water mixture as the working fluid, an ammonia–water absorption Refrigeration subSystem, and a CO 2 Compression Refrigeration subSystem. The System utilized the heat source in a cascade manner. The power subSystem converted the high-temperature portion of heat into power to drive the CO 2 Compression Refrigeration subSystem, thereby resulting in the generation of low-temperature cooling energy. The low-temperature portion of heat is converted into cooling energy to offer the heat sink of the CO 2 Compression Refrigeration subSystem. A simulation study was conducted, and results showed that the coefficient of performance of the proposed System was 0.277, which was approximately 50% higher than that of a conventional two-stage absorption Refrigeration System. This work may provide a new way to produce low-temperature cooling energy using mid-temperature heat source.
Somchai Wongwises - One of the best experts on this subject based on the ideXlab platform.
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application of the heat pipe to enhance the performance of the vapor Compression Refrigeration System
Case Studies in Thermal Engineering, 2019Co-Authors: Santiphap Nakkaew, Somchai Wongwises, Ahmet Selim Dalkılıç, Thunyawat Chitipalungsri, Ho Seon Ahn, Dongwook Jerng, Lazarus Godson Asirvatham, Omid MahianAbstract:Abstract This paper presents an application of the heat pipe to enhance the performance of the air conditioner. The study is done in two steps. First, the effect of pertinent parameters on the heat transfer rate of the heat pipe set is investigated. Then the heat pipe set is installed in the split-type air conditioner and tested in the actual condition. The heat pipe set consists of a heat pipe, holder, and plate fins. The length of the heat pipe is 300 mm. The working fluid inside the heat pipe is deionized water. Two different geometries of holder which are A-geometry and B-geometry are used in the study. Both holders are made of copper. The numbers of heat pipe in each set are 2, 4 and 6. The experimental results show that the maximum heat transfer rate obtained from the heat pipe set is about 240 W at the air velocity of 5 m/s and the heater surface temperature of 70 ๐C. The heat pipe set with A-geometry consisting of 6 heat pipes is the best configuration. However, this configuration provides the highest air-side pressure drop because of the highest velocity. The best heat pipe set is installed at the outlet of the compressor in the air conditioner with a cooling capacity of 9,000 BTU/hr. The experimental results show that the energy efficiency ratios (EER) of the air conditioners with heat pipe set are slightly higher than those of the conventional air conditioner. The EER of air conditioners with copper holder of heat pipe increases about 3.11%. The results from the present study are important for enhancing the performance of the vapor Compression Refrigeration System.
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miniature vapor Compression Refrigeration System for electronics cooling
Case Studies in Thermal Engineering, 2019Co-Authors: Akasi Poachaiyapoom, Jirawa Mounkong, Somchai Wongwises, Rattapon LeardkunAbstract:Abstract A miniature vapor Compression Refrigeration System using R134a is investigated for electronics cooling. The System consists of four main components: an evaporator, a compressor, a capillary tube, and a condenser. The evaporator is a micro-channel heat sink with 106 rectangular cross-sectional channels. Each micro-channel has a depth of 450 µm, a width of 150 µm, a wall thickness of 150 µm, and a length of 20 mm. Experimental conditions include compressor speeds ranging between 3000 and 6000 RPM and heating power of 100 W, 150 W, and 200 W. The experimental results show that increased compressor speed could reduce the surface temperature of the heater but also decrease the coefficient of performance (COP). The highest COP gained is 9.069 at a compressor speed of 3000 RPM and a heating power of 200 W, which yields the heater surface temperature of 73.3 °C. This miniature vapor Compression Refrigeration System could be used for electronics cooling with the most suitable conditions at heating power of 200 W and compressor speed of 3000 RPM. The proposed System is not suitable for electronics cooling at a heating power of 100 W and 150 W, because the heater surface temperature is less than 40 °C.
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Miniature vapor Compression Refrigeration System for electronics cooling
Elsevier, 2019Co-Authors: Akasi Poachaiyapoom, Rattapo Leardku, Jirawa Mounkong, Somchai WongwisesAbstract:A miniature vapor Compression Refrigeration System using R134a is investigated for electronics cooling. The System consists of four main components: an evaporator, a compressor, a capillary tube, and a condenser. The evaporator is a micro-channel heat sink with 106 rectangular cross-sectional channels. Each micro-channel has a depth of 450 µm, a width of 150 µm, a wall thickness of 150 µm, and a length of 20 mm. Experimental conditions include compressor speeds ranging between 3000 and 6000 RPM and heating power of 100 W, 150 W, and 200 W. The experimental results show that increased compressor speed could reduce the surface temperature of the heater but also decrease the coefficient of performance (COP). The highest COP gained is 9.069 at a compressor speed of 3000 RPM and a heating power of 200 W, which yields the heater surface temperature of 73.3 °C. This miniature vapor Compression Refrigeration System could be used for electronics cooling with the most suitable conditions at heating power of 200 W and compressor speed of 3000 RPM. The proposed System is not suitable for electronics cooling at a heating power of 100 W and 150 W, because the heater surface temperature is less than 40 °C. Keywords: Micro-channel, Vapor Compression System, Heat sink, Electronics coolin
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A performance comparison of vapour-Compression Refrigeration System using various alternative refrigerants
International Communications in Heat and Mass Transfer, 2010Co-Authors: Ahmet Selim Dalkılıç, Somchai WongwisesAbstract:Abstract A theoretical performance study on a traditional vapour-Compression Refrigeration System with refrigerant mixtures based on HFC134a, HFC152a, HFC32, HC290, HC1270, HC600, and HC600a was done for various ratios and their results are compared with CFC12, CFC22, and HFC134a as possible alternative replacements. In spite of the HC refrigerants' highly flammable characteristics, they are used in many applications, with attention being paid to the safety of the leakage from the System, as other refrigerants in recent years are not related with any effect on the depletion of the ozone layer and increase in global warming. Theoretical results showed that all of the alternative refrigerants investigated in the analysis have a slightly lower performance coefficient (COP) than CFC12, CFC22, and HFC134a for the condensation temperature of 50 °C and evaporating temperatures ranging between − 30 °C and 10 °C. Refrigerant blends of HC290/HC600a (40/60 by wt.%) instead of CFC12 and HC290/HC1270 (20/80 by wt.%) instead of CFC22 are found to be replacement refrigerants among other alternatives in this paper as a result of the analysis. The effects of the main parameters of performance analysis such as refrigerant type, degree of subcooling, and superheating on the refrigerating effect, coefficient of performance and volumetric Refrigeration capacity are also investigated for various evaporating temperatures.