以水-溴化锂溶液为工质的制冷/制热潜能储存系统特性研究

Research on characteristics of refrigerating/heating potential storage system using H_2O-LiBr as working fluid

详细介绍了以水-溴化锂为工作介质的制冷/制热潜能储存系统的工作原理,并根据循环流程及循环特点给出了循环热力计算数学模型,最后结合潜能储存循环计算结果对循环特性做出了详细分析.结果表明该系统可于较高储能密度下运行,且有较高性能系数,基于水在0℃以下结冰的现象,以水-溴化锂为工质的潜能储存系统比较适用于空调系统.当有低温热源时,储存的潜能还可以被转换成热能,或潜能被转换成冷能的同时还可以产生热能,这是传统的蓄能技术所不具有的.由于潜能储存系统工作循环的非连续性及采用溶晶装置及晶/液分离装置,溴化锂溶液的结晶问题可以被解决,故此循环的溶液浓度差大,蓄能密度高,是冰蓄能密度的3倍.

The working principle of refrigerating/heating potential storage (R/HPS) system in which water-lithium bromide is used as working fluid was presented. Based on the characteristics of the R/HPS cycle, the calculation models of the cycle are described in detail. With these models, a complete calculation and analysis are carried out for R/HPS system. Results show that the R/HPS system can run in a higher storage density and has a higher coefficient of performance (COP). And the system is usually suitable for air-conditioning system based on the phenomena that water can freeze at 0°C. The potential can be transferred to heat energy with low temperature heat resources, and the heat can be produced when potential is transferred into cold energy. The lithium bromide crystallization in rich solution tank does not influence the operation of the R/HPS system because the solution flow is discontinuous and LiBr crystal dissolving device and crystal/liquid split device are set in the system. The concentration difference between rich and poor solutions is larger in the R/HPS than that in common absorption refrigeration or heat pump. The storage density of the R/HPS system depends on the concentration difference. The larger concentration difference means that the R/HPS system has a larger storage density. The volume storage density of the R/HPS system is as 3 times as that of ice thermal energy storage system.