吸附式制冷中回质过程的作用

Effects of Mass Recovery on the Performance of Activated Carbon/Ammonia Adsorption Refrigeration Cycles

引入回质循环 ,设计了一套使用活性炭 -氨为工质对 ,用发动机余热驱动的吸附式汽车空调 .建立了回质循环的计算模型 ,对样机的回质过程及其对吸附式制冷循环性能的影响进行了定性分析和定量计算 ,并与基本循环、回热循环进行了对比 ,同时引入了回质系数表征回质完善度 .结果表明 ,回质过程大幅度提高了循环制冷量 ,但在某些工况下 ,也有可能降低系统的性能系数 ;金属及流体热容变化对回质过程的作用不明显 ;回质对性能的影响主要取决于工质对的吸附特性 .在不同的回质系数下 ,回质循环的性能变化遵循基本一致的规律 .回质过程对于循环性能系数的影响没有对循环制冷量的影响大 .

Environmental-friend adsorption refrigeration cycles were described. Advanced mass recovery cycle was presented. A bus air-conditioning system which is driven by bus waste heat employs activated carbon-ammonia as refrigerant. The mathematical model was presented. Pressure coefficient of mass recovery was introduced to indicate the mass recovery extent. The simulation results show that the mass recovery in activated carbon/ammonia adsorption cycle can play an important role to improve the performance of refrigeration cycle. The coefficient of performance might be increased or decreased with the mass recovery process due to different working conditions. The cooling capacity can be significantly increased with the mass recovery process. And the effects of mass recovery do not vary much due to different operating conditions. The effect of mass recovery on cooling capacity does not vary with the heat capacity of the bed metal. That the higher the condensing temperature is, the more the cooling capacity of mass recovery cycle will be improved. It can also be seen that the circle time will be much shorter and it will certainly enhance the cycle with higher cooling/heating power. And the performance variation follows the same regularity with different pressure coefficient of mass recovery.