摘要
Abstract
Absorption refrigeration is an ideal way to utilize solar energy in summer. For a single-stage solar-driven refrigeration cycle based on the typical working pair of LiBr/H2 O, the required generation temperature is up to 88. 0℃, which is too high for the commonly used flat plate solar collectors or vacuum glass tube solar collectors. Thus far, this problem has been addressed via two meth-ods:(1) using high-temperature solar collectors and (2) applying a two-stage absorption refrigeration cycle. In literature, a study per-taining to the former was conducted on the performance and economic feasibility of a 100 kW single-stage solar-driven absorption air conditioning system using heat pipe vacuum tube solar collectors, and another study pertaining to the latter was conducted on the per-formance and economic feasibility of a 100 kW two-stage solar energy absorption refrigeration air conditioning system using flat-plate so-lar collectors. Their results show that the system cost is high for the former and that the system cost is high and the coefficient of per-formance is low for the latter. In addition, the results show that the latter system is complicated. Thus, there are currently few commer-cial applications for the solar-driven absorption refrigeration system. In this study, a new method has been proposed that can address the existing problem, i. e. , the required generation temperature is too high for flat plate solar collectors or vacuum glass tube solar col-lectors in a solar-driven single-stage refrigeration cycle, using a new working pair instead of LiBr/H2 O. In this study, it is found that CaCl2/H2 O has an absorption characteristic benefitting refrigeration, although its absorption ability is limited owing to its relatively low solubility. Based on CaCl2/H2O, a new working pair of CaCl2-LiBr(1. 35:1)/H2O has been proposed. The crystallization tempera-ture, saturated vapor pressure, density, and viscosity of this working pair were systematically measured, and the results show that the required solar collector temperature or the generation temperature of CaCl2-LiBr(1. 35:1)/H2 O for a single-stage absorption refrigera-tion cycle is 6. 2℃ lower than that of LiBr/H2 O under the same refrigeration conditions. In addition, the corrosion rates of the carbon steel, 316L stainless steel, and copper in CaCl2-LiBr(1. 35:1)/H2 O were measured with a weight loss method, and the results show that the corrosion rates of 316L and copper are sufficiently low for practical applications.关键词
太阳能/吸收式制冷/工质对/结晶温度/饱和蒸气压Key words
solar energy/absorption refrigeration/working pair/crystallization temperature/saturated vapor pressure分类
通用工业技术
