【摘要】 在我国超低温箱采用的制冷剂一般为,高温级是R12/R22/R502,低温级是R13。近年来,国内部分单位和部门先后进口了不少的超低温箱,大都使用共沸混合制冷剂,如R500和R503,由于市场上没有或者很少销售这些工质,目前普遍出现超低温箱不能进行正常维修、使用等现状。为此针对进口超低温箱所存在的这类主要问题,结合国内实际情况,进行了制冷剂特性计算和替代工质的实验分析,同时也成功地为国内有关单位进行了进口超低温箱混合工质的替代工作。更多还原

【Abstract】 In our country, ultra-cold box usually use R12/R22/R502 in high-temperature and R13 in low-temperature. Recently years, some domestic companies and departments successively import a lot of ultra-cold boxes, most of which use azeotropic mixture refrigerant, such as R500 and R503. This kind of refrigerant, however, was rarely sold in domestic markets, as a result, the ultra-cold boxes could not run normally and be maintained in time. Based on the problems of ultra- cold boxes presented above and the domestic practical situation, this article calculates characteristics of refrigerants and analyses substitute refrigerant experimentally. At the same time, we introduce some successful rebuilds /innovations for the alternation to mixture refrigerant of the imported cold boxes.更多还原