【摘要】 为了提高跨临界CO2制冷系统性能,对具有补气特性的跨临界CO2制冷系统进行了理论分析。在该系统中,利用节流-分离-再膨胀的2次膨胀方法代替传统的1次膨胀方法,导出具有中间压强的饱和气体,再通过压缩机上的补气孔补入压缩腔,以提高系统制冷系数(COP)。该文研究了补气压强和补气开始时压缩腔内压强对系统性能的影响并给出优化方案。结果表明:对于给定的系统运行工况,当补气压强一定时,随补气开始时压缩腔内压强上升,在完全补气时系统COP增大,在部分补气时系统COP减小;当补气开始时压缩腔内压强一定时,随补气压强上升,在完全补气时系统COP减小,在部分补气时系统COP增大;存在最佳补气开始时压缩腔内压强和补气压强值,使得系统COP达到最大值。更多还原

【Abstract】 A trans-critical CO2 refrigeration system with compensating vapor input into a compressor economizer was developed to improve the performance of trans-critical CO2 refrigeration systems.In this system the expansion device is composed of two expansion valves and an economizer as a traditional expansion valve,with the vapor exiting the economizer entering the compression chamber.The influences of the economizer pressure and the pressure in the compression chamber at the beginning of the compensation process on the system performance were investigated theoretically.The results show that for a constant economizer pressure,increases of the compression chamber pressure at the beginning of compensation process increase the system COP assuming that all the vapor separated in the economizer enteres the compression chamber,the COP decreases if only some of the vapor separated in the economizer enteres the compression chamber.When the compression chamber pressure at the beginning of the compensation process is constant,increases of the economizer pressure reduce the COP when all of the vapor separated in the economizer enters the compression chamber and increase the COP when only part of the vapor separated in the economizer enteres the compression chamber.The economizer pressure and the compression chamber pressure at the beginning of compensation process can be optimized to give the best COP.更多还原