In the 199s, China has begun to study solar adsorption refrigeration refrigerators, but most of them are still confined to the laboratory, which has not reached the expected practical level, mainly due to the high preparation temperature and the time limitation of solar energy. At the same time, the need for pipeline connection between the outdoor adsorption bed and the indoor refrigerator of solar adsorption refrigeration refrigerator is also the main obstacle to the mass production stage of solar adsorption refrigeration refrigerator.
in order to solve the above defects, domestic researchers have made detailed analysis and research on solar solid adsorption refrigeration technology from the aspects of system cycle mechanism, selection of adsorption refrigeration working pairs, performance of solar refrigerator, analysis of internal and external characteristics and optimization design. Changjiang Sun, the Thermal Environment Research Office of the Refrigeration Institute of Shanghai Jiaotong University, has made two solar adsorption refrigerators according to the process and flow required for mass production after several years of painstaking research. The experimental results show that the performance of the refrigerator is relatively stable, which proves that the solar refrigerator has mature manufacturing conditions in technology.
in the solar adsorption refrigerator, the selection of adsorption working pairs is very important. Domestic researchers tried to study the adsorption characteristics of different adsorption working pairs, including CoF2-NH3, SrCl2-NH3, activated carbon-methanol, activated carbon-ethanol and so on. The experimental results show that the unit adsorption capacity of CoF2-NH3 working pair is large, the temperature requirement is low when the maximum adsorption capacity is reached, the adsorption period is short, and it does not agglomerate or swell after repeated adsorption, which provides new possibilities for miniaturization and practicality of chemical adsorption refrigeration system. SrCl2-NH3 working pair has a large adsorption refrigeration capacity, which is suitable for solar energy or low-grade waste heat, and is a working pair with excellent performance. Compared with activated carbon-ethanol working pair, activated carbon-methanol working pair is more suitable for solar solid adsorption ice maker.
High-efficiency solar collectors are the key components of solar refrigerators. There are two types of non-focusing solar collectors and focusing solar collectors. Among them, non-focusing solar collectors are divided into three types: flat plate type, vacuum tube type and CPC type. The collection temperature of these three collectors is not high, below 25℃, belonging to low-temperature or medium-temperature solar collectors. Focused solar collectors can be divided into three types: trough type, dish type and tower type. Usually, the collection temperature of these three types of focused solar collectors can reach above 3℃, which belongs to medium and high temperature collectors. For solar refrigerators, non-focused solar collectors are mainly used in solar adsorption refrigeration refrigerator systems, while focused solar collectors can be used in solar photoelectric refrigeration refrigerator systems. The research and utilization of solar collectors at home and abroad are mostly limited to the middle and low temperature range.