两级吸附式制冷工质对性能实验研究

摘要

Recently, a CaCl2?BaCl2?NH3 chemisorption freezing cycle driven by a low?temperature heat source has drawn an increasing a?mount of attention. To develop a working pair with a more desirable performance than CaCl2?BaCl2?NH3 , working pairs of CaCl2?NaBr?NH3 , SrCl2?BaCl2?NH3 , and SrCl2?NH4 Cl?NH3 were investigated and compared. Most composite adsorbents were developed with a novel matrix of expanded natural graphite treated with sulfuric acid ( ENG?TSA) , leaving one serial with expanded natural graphite ( ENG) for comparison. For SrCl2?NH4 Cl?NH3 and CaCl2?NaBr?NH3 , experimental results show that the maximum adsorption quantities are 95. 4％and 88. 6％ of the theoretical values, respectively. Simulation results indicate that the best results are obtained from CaCl2?NaBr?NH3 , and its specific cooling power (SCP) and coefficient of performance (COP) are as high as 260. 74 W/kgand 0. 285, respectively, which are 15. 1％ and 5. 6％ better than the values for CaCl2?BaCl2?NH3 . It is also noted that, for different working pairs, the COP, cooling ca?pacity, and SCP range from 0. 215 to 0. 285, 2 to 3. 65 kW, and 161. 4 to 260. 74 W/kg, respectively. Comparisons also show that the ENG?TSA matrix effectively improves the SCP. For example, the SCP of CaCl2?BaCl2?NH3 is improved by 40. 2％, when compared with a working pair with the ENG matrix.%本文针对不同两级吸附工质对CaCl2?NaBr?NH3,CaCl2?BaCl2?NH3,SrCl2?BaCl2?NH3与SrCl2?NH4 Cl?NH3进行了实验研究,同时模拟了两级吸附制冷样机的工作性能.结果表明:SrCl2?NH4 Cl?NH3与CaCl2?NaBr?NH3的循环吸附量可以分别达到理论值的95.4％与88.6％;对于不同两级吸附工质对,样机系统的COP、制冷量与SCP分别介于0.215～0.285、2～3.65 kW与161.4～260.74 W/kg;采用硫化石墨配置吸附剂能够大幅度提高两级制冷系统的SCP,以CaCl2?BaCl2?NH3为例,与采用普通石墨作为基质相比,采用硫化石墨的系统SCP最高可以提高40.2％.