| Today,with the increasingly serious environmental problems and huge energy consumption,environmental friendliness,comprehensive utilization of energy,use of alternative energy and coordinated economic development have become the common goals of people in today's society.Adsorption refrigeration technology has been studied deeply by scholars from all over the world because of its advantages such as using environment friendly refrigerants,no greenhouse effect problems,no moving parts in the refrigeration system and easy to move,and energy conservation driven by low-grade heat source.Adsorption refrigeration technology is consistent with the environmental protection concept of harmonious development of global economy,energy and environment,and has a broad application prospect.However,its wide application has been limited due to its generally low refrigeration efficiency.The type of adsorption working medium,the refrigeration cycle and the heat and mass transfer of adsorption bed all have a great influence on the performance of adsorption refrigeration system.In this paper,silica gel / water adsorption working pairs are used to study the performance changes of continuous regeneration adsorption refrigeration system under different working conditions.In this paper,a continuous re-heating silica gel/water adsorption refrigeration experiment bench was firstly built.The electric heating water tank is designed as the heat source of the system.The cooling tower cools the cooling water circuit.The constant temperature water tank provides a constant cold source for the system,and the stability of the system is tested.Then the simulation model of the system is built by Matlab / Simulink.After the reliability of the simulation model is verified,the influence of different operating conditions such as desorption / adsorption time,heat recovery time,different temperature of chilled water and cooling water,different temperature of heat source on the performance of the system is numerically solved and compared with the experimental results.Through the comparative analysis of simulation results and experimental results,it can be concluded that the temperature of heat source,chilled water and cooling water,desorption / adsorption time and regeneration time have great influence on the system performance.(1)When the desorption/adsorption time is between 600s~1400s,with the increase of time,the refrigerating capacity of the system will increase and the COP will decrease gradually.After comprehensive consideration,the optimal desorption/adsorption time of the experimental system is 990 s and the heat recovery time is 90 s.(2)With the increase of heat source temperature,the COP and the cooling capacity of the system are increasing,but the cop curve increases first,then decreases,then increases and then decreases.There are two peak values of COP in the process of increasing the heat source temperature.The best value is that when the hot water temperature reaches 85?,the COP of the system reaches 0.39.The suitable temperature range of the heat source inlet is 65?~90?.(3)Under the same other working conditions,when the cooling water temperature range is 25?~40?,the system performance decreases with the increase of cooling water temperature.For every 4? increase of cooling water,the cooling capacity of the system decreases by 6%~21%,and the COP of the system decreases by 5%~19%;When the temperature range of chilled water is 5?~25 ?,the system performance increases with the increase of chilled water temperature.For every 5? rise in chilled water temperature,the cooling capacity of the system increases by 7%~18%,and the COP of the system increases by 6%~20%. |
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