The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
R.z. Wang - One of the best experts on this subject based on the ideXlab platform.
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Experimental investigation on a small pumpless ORC (organic rankine cycle) system driven by the low temperature Heat Source
Energy, 2015Co-Authors: Liwei Wang, R.z. Wang, Long Jiang, Z.s. ZhouAbstract:A small pumpless ORC (organic rankine cycle) system with different scroll expanders modified from compressors of the automobile air-conditioner is established, and the refrigerant R245fa is chosen as the working fluid. Different hot water temperatures of 80, 85, 90 and 95 °C are employed to drive the pumpless ORC system. Experimental results show that a maximum shaft power of 361.0 W is obtained under the hot water temperature of 95 °C, whereas the average shaft power is 155.8 W. The maximum energy efficiency of 2.3% and the maximum exergy efficiency of 12.8% are obtained at the hot water temperature of 90 °C. Meanwhile a test rig for investigating the mechanical loss of the scroll expander is established. The torque caused by the internal mechanical friction of the expander is about 0.4 N m. Additionally, another scroll expander with a displacement of 86ml/r is also employed to investigate how scroll expander displacement influences the performance of the pumpless ORC system. Finally, the performance of the pumpless ORC system is compared with that of the conventional ORC system, and experimental results show that the small pumpless ORC system has more advantages for the low-grade Heat recovery.
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Study of the new composite adsorbent of salt LiCl/silica gel–methanol used in an innovative adsorption cooling machine driven by low temperature Heat Source
Renewable Energy, 2014Co-Authors: Z. S. Lu, R.z. WangAbstract:An adsorption cooling machine with LiCl/Silica gel–methanol was designed and tested, which can work for air conditioning and cold storage. The machine can be driven by low temperature Heat Source, such as solar energy and industrial waste Heat. The composite adsorbent of LiCl/Silica gel has higher adsorption capacity and the methanol has a higher working pressure. So, the cooling performance, system's reliability and the adsorbent's mass transfer performance can be improved. The adsorption machine was experimentally investigated. The test results show that the cycle time and Heat recovery process has more influence on COP (Coefficient of Performance) than on cooling capacity. The mass recovery process has significant influence both on cooling capacity and COP. When the cycle time is prolonged from 460 s to 760 s, the cooling capacity and COP increased by 4.3% and 20.6%, respectively. When the hot water inlet temperature, cooling water inlet temperature, cooling medium outlet temperature and Heat recovery time are 75 °C, 31 °C, 5 °C and 60 s, respectively, the cooling capacity is improved by 6.3% by Heat recovery process while the COP is improved by 27.3%. When the mass recovery time extends from 50 s to 120 s, the cooling capacity and COP increase by 68.4% and 53.3%. When the hot water inlet temperature is about 88 °C, the cooling water inlet temperature is about 25 °C, the adsorption machine produced -4 °C of cooling medium, the cooling capacity and COP were about 1.0 kW and 0.13, respectively.
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Study of the new composite adsorbent of salt LiCl/silica gel-methanol used in an innovative adsorption cooling machine driven by low temperature Heat Source
Renewable Energy, 2014Co-Authors: Z. S. Lu, R.z. WangAbstract:An adsorption cooling machine with LiCl/Silica gel-methanol was designed and tested, which can work for air conditioning and cold storage. The machine can be driven by low temperature Heat Source, such as solar energy and industrial waste Heat. The composite adsorbent of LiCl/Silica gel has higher adsorption capacity and the methanol has a higher working pressure. So, the cooling performance, system's reliability and the adsorbent's mass transfer performance can be improved. The adsorption machine was experimentally investigated. The test results show that the cycle time and Heat recovery process has more influence on COP (Coefficient of Performance) than on cooling capacity. The mass recovery process has significant influence both on cooling capacity and COP. When the cycle time is prolonged from 460s to 760s, the cooling capacity and COP increased by 4.3% and 20.6%, respectively. When the hot water inlet temperature, cooling water inlet temperature, cooling medium outlet temperature and Heat recovery time are 75°C, 31°C, 5°C and 60s, respectively, the cooling capacity is improved by 6.3% by Heat recovery process while the COP is improved by 27.3%. When the mass recovery time extends from 50s to 120s, the cooling capacity and COP increase by 68.4% and 53.3%. When the hot water inlet temperature is about 88°C, the cooling water inlet temperature is about 25°C, the adsorption machine produced -4°C of cooling medium, the cooling capacity and COP were about 1.0kW and 0.13, respectively. © 2013 Elsevier Ltd.
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Two-stage liquid desiccant dehumidification/regeneration
UECTC'09 - Proceedings of 2009 US-EU-China Thermophysics Conference - Renewable Energy, 2009Co-Authors: Z Q Xiong, Y J Dai, R.z. Wang, B.l. XiaAbstract:Air conditioning system based on liquid desiccant is a potential alternative to conventional vapor air conditioning system due to its advantages such as utilization of low temperature Heat Source, independently humidity and temperature control strategy and high energy storage capacity. In this paper, the technologies of two-stage liquid desiccant dehumidification which adopting LiCl solution and CaCl 2 solution as the desiccant solution, is analyzed and applied in a new air conditioning system in Shanghai summer condition. The two-stage liquid desiccant dehumidification subsystem shows the advantages of easier regeneration and lower cost due to the application of CaCl 2 compared with the LiCl alone dehumidification. A mathematical model is build to simulate its performance. It is found that the regeneration Heat is reduced compared with LiCl alone dehumidification. The Tcop of the two-stage dehumidification applied in a hybrid system reaches 0.68. Two-stage liquid desiccant dehumidification is a feasible solution for dehumidification in Shanghai in China. Copyright © 2009 by ASME.
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Study of a novel silica gel-water adsorption chiller. Part I. Design and performance prediction
International Journal of Refrigeration, 2005Co-Authors: D. C. Wang, Z. Z. Xia, H. Zhai, J Y Wu, R.z. Wang, W. D. DouAbstract:A novel silica gel-water adsorption chiller is designed and its performance is predicted in this work. This adsorption chiller includes three vacuum chambers: two adsorption/desorption (or evaporation/condensation) vacuum chambers and one Heat pipe working vacuum chamber as the evaporator. One adsorber, one condenser and one evaporator are housed in the same chamber to constitute an adsorption/desorption unit. The evaporators of two adsorption/desorption units are combined together by a Heat-pipe Heat exchanger to make continuous refrigerating capacity. In this chiller, a vacuum valve is installed between the two adsorption/desorption vacuum chambers to increase its performance especially when the chiller is driven by a low temperature Heat Source. The operating reliability of the chiller rises greatly because of using fewer valves. Furthermore, the performance of the chiller is predicted. The simulated results show that the refrigerating capacity is more than 10 kW under a typical working condition with hot water temperature of 85 °C, the cooling water temperature of 31 °C and the chilled water inlet temperature of 15 °C. The COP exceeds 0.5 even under a Heat Source temperature of 65 °C. © 2005 Elsevier Ltd and IIR. All rights reserved.
W. D. Dou - One of the best experts on this subject based on the ideXlab platform.
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Study of a novel silica gel-water adsorption chiller. Part I. Design and performance prediction
International Journal of Refrigeration, 2005Co-Authors: D. C. Wang, Z. Z. Xia, H. Zhai, J Y Wu, R.z. Wang, W. D. DouAbstract:A novel silica gel-water adsorption chiller is designed and its performance is predicted in this work. This adsorption chiller includes three vacuum chambers: two adsorption/desorption (or evaporation/condensation) vacuum chambers and one Heat pipe working vacuum chamber as the evaporator. One adsorber, one condenser and one evaporator are housed in the same chamber to constitute an adsorption/desorption unit. The evaporators of two adsorption/desorption units are combined together by a Heat-pipe Heat exchanger to make continuous refrigerating capacity. In this chiller, a vacuum valve is installed between the two adsorption/desorption vacuum chambers to increase its performance especially when the chiller is driven by a low temperature Heat Source. The operating reliability of the chiller rises greatly because of using fewer valves. Furthermore, the performance of the chiller is predicted. The simulated results show that the refrigerating capacity is more than 10 kW under a typical working condition with hot water temperature of 85 °C, the cooling water temperature of 31 °C and the chilled water inlet temperature of 15 °C. The COP exceeds 0.5 even under a Heat Source temperature of 65 °C. © 2005 Elsevier Ltd and IIR. All rights reserved.
Z. S. Lu - One of the best experts on this subject based on the ideXlab platform.
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Study of the new composite adsorbent of salt LiCl/silica gel–methanol used in an innovative adsorption cooling machine driven by low temperature Heat Source
Renewable Energy, 2014Co-Authors: Z. S. Lu, R.z. WangAbstract:An adsorption cooling machine with LiCl/Silica gel–methanol was designed and tested, which can work for air conditioning and cold storage. The machine can be driven by low temperature Heat Source, such as solar energy and industrial waste Heat. The composite adsorbent of LiCl/Silica gel has higher adsorption capacity and the methanol has a higher working pressure. So, the cooling performance, system's reliability and the adsorbent's mass transfer performance can be improved. The adsorption machine was experimentally investigated. The test results show that the cycle time and Heat recovery process has more influence on COP (Coefficient of Performance) than on cooling capacity. The mass recovery process has significant influence both on cooling capacity and COP. When the cycle time is prolonged from 460 s to 760 s, the cooling capacity and COP increased by 4.3% and 20.6%, respectively. When the hot water inlet temperature, cooling water inlet temperature, cooling medium outlet temperature and Heat recovery time are 75 °C, 31 °C, 5 °C and 60 s, respectively, the cooling capacity is improved by 6.3% by Heat recovery process while the COP is improved by 27.3%. When the mass recovery time extends from 50 s to 120 s, the cooling capacity and COP increase by 68.4% and 53.3%. When the hot water inlet temperature is about 88 °C, the cooling water inlet temperature is about 25 °C, the adsorption machine produced -4 °C of cooling medium, the cooling capacity and COP were about 1.0 kW and 0.13, respectively.
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Study of the new composite adsorbent of salt LiCl/silica gel-methanol used in an innovative adsorption cooling machine driven by low temperature Heat Source
Renewable Energy, 2014Co-Authors: Z. S. Lu, R.z. WangAbstract:An adsorption cooling machine with LiCl/Silica gel-methanol was designed and tested, which can work for air conditioning and cold storage. The machine can be driven by low temperature Heat Source, such as solar energy and industrial waste Heat. The composite adsorbent of LiCl/Silica gel has higher adsorption capacity and the methanol has a higher working pressure. So, the cooling performance, system's reliability and the adsorbent's mass transfer performance can be improved. The adsorption machine was experimentally investigated. The test results show that the cycle time and Heat recovery process has more influence on COP (Coefficient of Performance) than on cooling capacity. The mass recovery process has significant influence both on cooling capacity and COP. When the cycle time is prolonged from 460s to 760s, the cooling capacity and COP increased by 4.3% and 20.6%, respectively. When the hot water inlet temperature, cooling water inlet temperature, cooling medium outlet temperature and Heat recovery time are 75°C, 31°C, 5°C and 60s, respectively, the cooling capacity is improved by 6.3% by Heat recovery process while the COP is improved by 27.3%. When the mass recovery time extends from 50s to 120s, the cooling capacity and COP increase by 68.4% and 53.3%. When the hot water inlet temperature is about 88°C, the cooling water inlet temperature is about 25°C, the adsorption machine produced -4°C of cooling medium, the cooling capacity and COP were about 1.0kW and 0.13, respectively. © 2013 Elsevier Ltd.
D. C. Wang - One of the best experts on this subject based on the ideXlab platform.
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Study of a novel silica gel-water adsorption chiller. Part I. Design and performance prediction
International Journal of Refrigeration, 2005Co-Authors: D. C. Wang, Z. Z. Xia, H. Zhai, J Y Wu, R.z. Wang, W. D. DouAbstract:A novel silica gel-water adsorption chiller is designed and its performance is predicted in this work. This adsorption chiller includes three vacuum chambers: two adsorption/desorption (or evaporation/condensation) vacuum chambers and one Heat pipe working vacuum chamber as the evaporator. One adsorber, one condenser and one evaporator are housed in the same chamber to constitute an adsorption/desorption unit. The evaporators of two adsorption/desorption units are combined together by a Heat-pipe Heat exchanger to make continuous refrigerating capacity. In this chiller, a vacuum valve is installed between the two adsorption/desorption vacuum chambers to increase its performance especially when the chiller is driven by a low temperature Heat Source. The operating reliability of the chiller rises greatly because of using fewer valves. Furthermore, the performance of the chiller is predicted. The simulated results show that the refrigerating capacity is more than 10 kW under a typical working condition with hot water temperature of 85 °C, the cooling water temperature of 31 °C and the chilled water inlet temperature of 15 °C. The COP exceeds 0.5 even under a Heat Source temperature of 65 °C. © 2005 Elsevier Ltd and IIR. All rights reserved.
L. G. Gordeeva - One of the best experts on this subject based on the ideXlab platform.
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A Thermodynamic Analysis of a New Cycle for Adsorption Heat Pump “Heat from Cold”: Effect of the Working Pair on Cycle Efficiency
Thermal Engineering, 2018Co-Authors: N. M. Voskresenskii, B. N. Okunev, L. G. GordeevaAbstract:A thermodynamic analysis was carried out for a new “Heat from Cold” (HeCol) adsorption cycle for transformation of the ambient Heat using the following working pairs: activated carbon ASM-35.4–methanol or composite sorbent LiCl/silica gel–methanol. Unlike the conventional cycle of an adsorption thermal engine where the adsorbent is regenerated at a constant pressure by its Heating up to 80–150°C, the adsorbent in the HeCol cycle is regenerated by depressurization, which is performed due to a low ambient temperature. The balances of energy and entropy are calculated at each cycle stage and each element of the transformer under conditions of ideal Heat transfer. The performance of the cycle for both pairs is compared. The threshold ambient temperature above which useful Heat is not produced has been determined. The threshold values depend only on the absorption potential of methanol. It is demonstrated that useful Heat with a high temperature potential of approximately 40°C can be obtained from a natural Source of low-potential Heat (such as a river, lake, or sea) only at a sufficiently low ambient temperature. The cycle with the composite sorbent LiCl/silica gel–methanol yielded much more useful Heat than the cycle with the activated carbon ASM-35.4–methanol due to the features of the characteristic curve for methanol vapor adsorption on the composite sorbent. The amount of useful Heat increases with decreasing ambient temperature and increasing temperature of the natural Low-Temperature Heat Source. The examined cycle can be used for upgrading the ambient Heat temperature potential in countries with a cold climate.
