The Experts below are selected from a list of 11631 Experts worldwide ranked by ideXlab platform
Gunjoo Jung - One of the best experts on this subject based on the ideXlab platform.
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Efficiency enhancement of the ocean thermal energy conversion system with a vapor–vapor ejector
Advances in Mechanical Engineering, 2015Co-Authors: Jung-in Yoon, Sung hoon Seol, Byung Hyo Ye, Soo Jung Ha, Gunjoo JungAbstract:In this article, 20 kW ocean thermal energy conversion with a vapor–vapor ejector is newly proposed. As a vapor–vapor ejector is installed in the system, the pressure difference between the turbine inlet and outlet increases. Therefore, the amount of the working fluid required for the total turbine work of 20 kW is less than when no vapor–vapor ejector is installed. Therefore, installing a vapor–vapor ejector in the system decreases the Evaporation Capacity and the pump work. The performance analysis considered the outlet pressure of the high-stage turbine, the mass flow ratio of the working fluid at the outlet of a separator just after the high-stage turbine, and the nozzle diameters of the vapor–vapor ejector. As the outlet pressure of high-stage turbine becomes lower, the turbine gross power of high-stage turbine and system efficiency increase although lower outlet pressure of high-stage turbine results in lower ejector performance. Similarly, in terms of mass flow ratio, the highest system efficiency ...
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Efficiency enhancement of the ocean thermal energy conversion system with a vapor–vapor ejector
SAGE Publishing, 2015Co-Authors: Ho-saeng Lee, Sung hoon Seol, Chang-hyo Son, Jung-in Yoon, Hyeon-ju Kim, Gunjoo JungAbstract:In this article, 20 kW ocean thermal energy conversion with a vapor–vapor ejector is newly proposed. As a vapor–vapor ejector is installed in the system, the pressure difference between the turbine inlet and outlet increases. Therefore, the amount of the working fluid required for the total turbine work of 20 kW is less than when no vapor–vapor ejector is installed. Therefore, installing a vapor–vapor ejector in the system decreases the Evaporation Capacity and the pump work. The performance analysis considered the outlet pressure of the high-stage turbine, the mass flow ratio of the working fluid at the outlet of a separator just after the high-stage turbine, and the nozzle diameters of the vapor–vapor ejector. As the outlet pressure of high-stage turbine becomes lower, the turbine gross power of high-stage turbine and system efficiency increase although lower outlet pressure of high-stage turbine results in lower ejector performance. Similarly, in terms of mass flow ratio, the highest system efficiency was shown at mass flow ratio of 0.4 at the outlet of a separator just after the high-stage turbine. On the other hand, the performance of the ejector at mass flow ratio of 0.5 at the outlet of a separator was largest. When the nozzle diameters of the vapor–vapor ejector are properly designed, the vapor–vapor ejector shows the highest performance. After the optimization of the operation parameters, system efficiency of the proposed ocean thermal energy conversion power cycle was 2.47%, relatively 15% higher than that of the basic ocean thermal energy conversion power cycle (2.2%)
Jung-in Yoon - One of the best experts on this subject based on the ideXlab platform.
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Experimental study on the performance of the vapor injection refrigeration system with an economizer for intermediate pressures
Heat and Mass Transfer, 2018Co-Authors: Chang-uk Moon, Chang-hyo Son, Sang-young An, Kwang-hwan Choi, Jung-in Yoon, Min-ju Jeon, Soo Jung Ha, Young Bok Kim, Joon Hyuk LeeAbstract:In this study, to investigate the performance characteristics of vapor injection refrigeration system with an economizer at an intermediate pressure, the vapor injection refrigeration system was analyzed under various experiment conditions. As a result, the optimum design data of the vapor injection refrigeration system with an economizer were obtained. The findings from this study can be summarized as follows. The mass flow rate through the compressor increases with intermediate pressure. The compression power input showed an increasing trend under all the test conditions. The Evaporation Capacity increased and then decreased at the intermediate pressure, and as such, it became maximum at the given intermediate pressure. The increased mass flow rate of the by-passed refrigerant enhanced the Evaporation Capacity at the low medium pressure range, but the increased saturation temperature limited the subcooling degree of the liquid refrigerant after the application of the economizer when the intermediate pressure kept rising, and degenerated the Evaporation Capacity. The coefficient of performance (COP) increased and then decreased with respect to the intermediate pressures under all the experiment conditions. Nevertheless, there was an optimum intermediate pressure for the maximum COP under each experiment condition. Therefore, the optimum intermediate pressure in this study was found at −99.08 kPa, which is the theoretical standard medium pressure under all the test conditions.
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Performance analysis of OTEC power cycle with a liquid–vapor ejector using R32/R152a
Heat and Mass Transfer, 2015Co-Authors: Jung-in Yoon, Sung hoon Seol, Chang-hyo Son, Hyeon-uk Kim, Suk-ho Jung, Hyeon-ju Kim, Ho-saeng LeeAbstract:In this paper, the condensation and Evaporation Capacity, turbine work, efficiency, and main component size of the Ocean Thermal Energy Conversion (OTEC) power system with a liquid–vapor ejector are presented to offer the basic design data for the operating parameters of the system. The analysis procedure was performed with a simulation program called Aspentech HYSYS. The working fluid used in this system is the R32/R152a mixture. The operating parameters considered in this study include the vapor quality at the reheat outlet, the pressure ratio of the ejector, the inlet pressure of turbine 2, entrainment ratio of the liquid–vapor ejector etc. The main results are summarized as follows. The efficiency of the OTEC power cycle is closely related to the entrainment ratio of the liquid–vapor ejector. Also, the increase rate of the efficiency of proposed OTEC power cycle using the liquid–vapor ejector is 16 % higher than that of basic OTEC power cycle. Furthermore, regarding the reduction ratios of the system size that affects the initial cost, the reduction ratios of the evaporator size and the condenser size are about 13 and 14 % higher than those of basic OTEC power cycle, respectively. And, the pump power and the mass flow rate of the required refrigerant are 8 and 4 %, respectively. Therefore, the proposed OTEC power cycle is more advantageous than basic OTEC power cycle because of the compactness and high-efficiency of the system.
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Efficiency enhancement of the ocean thermal energy conversion system with a vapor–vapor ejector
Advances in Mechanical Engineering, 2015Co-Authors: Jung-in Yoon, Sung hoon Seol, Byung Hyo Ye, Soo Jung Ha, Gunjoo JungAbstract:In this article, 20 kW ocean thermal energy conversion with a vapor–vapor ejector is newly proposed. As a vapor–vapor ejector is installed in the system, the pressure difference between the turbine inlet and outlet increases. Therefore, the amount of the working fluid required for the total turbine work of 20 kW is less than when no vapor–vapor ejector is installed. Therefore, installing a vapor–vapor ejector in the system decreases the Evaporation Capacity and the pump work. The performance analysis considered the outlet pressure of the high-stage turbine, the mass flow ratio of the working fluid at the outlet of a separator just after the high-stage turbine, and the nozzle diameters of the vapor–vapor ejector. As the outlet pressure of high-stage turbine becomes lower, the turbine gross power of high-stage turbine and system efficiency increase although lower outlet pressure of high-stage turbine results in lower ejector performance. Similarly, in terms of mass flow ratio, the highest system efficiency ...
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Efficiency enhancement of the ocean thermal energy conversion system with a vapor–vapor ejector
SAGE Publishing, 2015Co-Authors: Ho-saeng Lee, Sung hoon Seol, Chang-hyo Son, Jung-in Yoon, Hyeon-ju Kim, Gunjoo JungAbstract:In this article, 20 kW ocean thermal energy conversion with a vapor–vapor ejector is newly proposed. As a vapor–vapor ejector is installed in the system, the pressure difference between the turbine inlet and outlet increases. Therefore, the amount of the working fluid required for the total turbine work of 20 kW is less than when no vapor–vapor ejector is installed. Therefore, installing a vapor–vapor ejector in the system decreases the Evaporation Capacity and the pump work. The performance analysis considered the outlet pressure of the high-stage turbine, the mass flow ratio of the working fluid at the outlet of a separator just after the high-stage turbine, and the nozzle diameters of the vapor–vapor ejector. As the outlet pressure of high-stage turbine becomes lower, the turbine gross power of high-stage turbine and system efficiency increase although lower outlet pressure of high-stage turbine results in lower ejector performance. Similarly, in terms of mass flow ratio, the highest system efficiency was shown at mass flow ratio of 0.4 at the outlet of a separator just after the high-stage turbine. On the other hand, the performance of the ejector at mass flow ratio of 0.5 at the outlet of a separator was largest. When the nozzle diameters of the vapor–vapor ejector are properly designed, the vapor–vapor ejector shows the highest performance. After the optimization of the operation parameters, system efficiency of the proposed ocean thermal energy conversion power cycle was 2.47%, relatively 15% higher than that of the basic ocean thermal energy conversion power cycle (2.2%)
Zhifang Hang - One of the best experts on this subject based on the ideXlab platform.
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experimental investigation of a novel batch Evaporation system coupled mechanical vapor recompression technology and steam heat storage technology
Innovative Food Science and Emerging Technologies, 2021Co-Authors: Junjie Chen, Dong Han, Zhifang HangAbstract:Abstract In order to address the high energy consumption and low efficiency in batched food Evaporation industry, such as beer boiling, lactose crystallization, drug concentration, a novel batched mechanical vapor recompression Evaporation device coupled the heat storage technology and mechanical vapor recompression technology was assembled to capture and reuse the waste heat from secondary steam and reduce the water consumption. The relevant key parameters affecting the overall performance were investigated and analyzed, including Evaporation temperature, interval time, startup time and compressor frequency. In a practical sense, the thermodynamic, economic, as well as the environmental performance of the proposed system was compared with the previous single-effect Evaporation technology. Experimental results exhibited that the proposed system could accomplish efficient batch Evaporation process at specific interval time with only a small amount of electricity, as the temperature loss of steam accumulator was approximately 1 °C. It was found that the Evaporation temperature was a positive factor for the overall performance of the system, while the startup time of the whole system showed an opposite effect, subject to the startup time of the steam compressor. Furthermore, it was highlighted that the Evaporation Capacity of novel system was very sensitive to compressor frequency, while a minimum value of 64.5 kWht−1 for specific heating energy consumption emerged at f = 65 Hz. Therefore, the operating cost and standard coal consumption could be saved by 85.26% and 83.66% compared to the single-effect Evaporation technology, respectively, which demonstrated the significant superiority of the proposed method in economic and environmental benefits in batch Evaporation industry.
Sung hoon Seol - One of the best experts on this subject based on the ideXlab platform.
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Performance analysis of OTEC power cycle with a liquid–vapor ejector using R32/R152a
Heat and Mass Transfer, 2015Co-Authors: Jung-in Yoon, Sung hoon Seol, Chang-hyo Son, Hyeon-uk Kim, Suk-ho Jung, Hyeon-ju Kim, Ho-saeng LeeAbstract:In this paper, the condensation and Evaporation Capacity, turbine work, efficiency, and main component size of the Ocean Thermal Energy Conversion (OTEC) power system with a liquid–vapor ejector are presented to offer the basic design data for the operating parameters of the system. The analysis procedure was performed with a simulation program called Aspentech HYSYS. The working fluid used in this system is the R32/R152a mixture. The operating parameters considered in this study include the vapor quality at the reheat outlet, the pressure ratio of the ejector, the inlet pressure of turbine 2, entrainment ratio of the liquid–vapor ejector etc. The main results are summarized as follows. The efficiency of the OTEC power cycle is closely related to the entrainment ratio of the liquid–vapor ejector. Also, the increase rate of the efficiency of proposed OTEC power cycle using the liquid–vapor ejector is 16 % higher than that of basic OTEC power cycle. Furthermore, regarding the reduction ratios of the system size that affects the initial cost, the reduction ratios of the evaporator size and the condenser size are about 13 and 14 % higher than those of basic OTEC power cycle, respectively. And, the pump power and the mass flow rate of the required refrigerant are 8 and 4 %, respectively. Therefore, the proposed OTEC power cycle is more advantageous than basic OTEC power cycle because of the compactness and high-efficiency of the system.
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Efficiency enhancement of the ocean thermal energy conversion system with a vapor–vapor ejector
Advances in Mechanical Engineering, 2015Co-Authors: Jung-in Yoon, Sung hoon Seol, Byung Hyo Ye, Soo Jung Ha, Gunjoo JungAbstract:In this article, 20 kW ocean thermal energy conversion with a vapor–vapor ejector is newly proposed. As a vapor–vapor ejector is installed in the system, the pressure difference between the turbine inlet and outlet increases. Therefore, the amount of the working fluid required for the total turbine work of 20 kW is less than when no vapor–vapor ejector is installed. Therefore, installing a vapor–vapor ejector in the system decreases the Evaporation Capacity and the pump work. The performance analysis considered the outlet pressure of the high-stage turbine, the mass flow ratio of the working fluid at the outlet of a separator just after the high-stage turbine, and the nozzle diameters of the vapor–vapor ejector. As the outlet pressure of high-stage turbine becomes lower, the turbine gross power of high-stage turbine and system efficiency increase although lower outlet pressure of high-stage turbine results in lower ejector performance. Similarly, in terms of mass flow ratio, the highest system efficiency ...
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Efficiency enhancement of the ocean thermal energy conversion system with a vapor–vapor ejector
SAGE Publishing, 2015Co-Authors: Ho-saeng Lee, Sung hoon Seol, Chang-hyo Son, Jung-in Yoon, Hyeon-ju Kim, Gunjoo JungAbstract:In this article, 20 kW ocean thermal energy conversion with a vapor–vapor ejector is newly proposed. As a vapor–vapor ejector is installed in the system, the pressure difference between the turbine inlet and outlet increases. Therefore, the amount of the working fluid required for the total turbine work of 20 kW is less than when no vapor–vapor ejector is installed. Therefore, installing a vapor–vapor ejector in the system decreases the Evaporation Capacity and the pump work. The performance analysis considered the outlet pressure of the high-stage turbine, the mass flow ratio of the working fluid at the outlet of a separator just after the high-stage turbine, and the nozzle diameters of the vapor–vapor ejector. As the outlet pressure of high-stage turbine becomes lower, the turbine gross power of high-stage turbine and system efficiency increase although lower outlet pressure of high-stage turbine results in lower ejector performance. Similarly, in terms of mass flow ratio, the highest system efficiency was shown at mass flow ratio of 0.4 at the outlet of a separator just after the high-stage turbine. On the other hand, the performance of the ejector at mass flow ratio of 0.5 at the outlet of a separator was largest. When the nozzle diameters of the vapor–vapor ejector are properly designed, the vapor–vapor ejector shows the highest performance. After the optimization of the operation parameters, system efficiency of the proposed ocean thermal energy conversion power cycle was 2.47%, relatively 15% higher than that of the basic ocean thermal energy conversion power cycle (2.2%)
Junjie Chen - One of the best experts on this subject based on the ideXlab platform.
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experimental investigation of a novel batch Evaporation system coupled mechanical vapor recompression technology and steam heat storage technology
Innovative Food Science and Emerging Technologies, 2021Co-Authors: Junjie Chen, Dong Han, Zhifang HangAbstract:Abstract In order to address the high energy consumption and low efficiency in batched food Evaporation industry, such as beer boiling, lactose crystallization, drug concentration, a novel batched mechanical vapor recompression Evaporation device coupled the heat storage technology and mechanical vapor recompression technology was assembled to capture and reuse the waste heat from secondary steam and reduce the water consumption. The relevant key parameters affecting the overall performance were investigated and analyzed, including Evaporation temperature, interval time, startup time and compressor frequency. In a practical sense, the thermodynamic, economic, as well as the environmental performance of the proposed system was compared with the previous single-effect Evaporation technology. Experimental results exhibited that the proposed system could accomplish efficient batch Evaporation process at specific interval time with only a small amount of electricity, as the temperature loss of steam accumulator was approximately 1 °C. It was found that the Evaporation temperature was a positive factor for the overall performance of the system, while the startup time of the whole system showed an opposite effect, subject to the startup time of the steam compressor. Furthermore, it was highlighted that the Evaporation Capacity of novel system was very sensitive to compressor frequency, while a minimum value of 64.5 kWht−1 for specific heating energy consumption emerged at f = 65 Hz. Therefore, the operating cost and standard coal consumption could be saved by 85.26% and 83.66% compared to the single-effect Evaporation technology, respectively, which demonstrated the significant superiority of the proposed method in economic and environmental benefits in batch Evaporation industry.