泵驱动两相复合制冷机组变频运转特性

Frequency Variable Characteristics for Pump-driven Two Phase Loop Integrated With Vapor Compression Refrigeration System

为研究泵驱动两相复合制冷机组的工作特性,特别是换热性能随工质泵频率和室内外温差的变化规律,搭建泵驱动两相复合制冷机组的实验装置,对其进行了实验研究.在本实验装置中,蒸气压缩制冷模式分别采用2.63 k W压缩机和3.75 k W压缩机作为驱动元件,泵驱动两相冷却模式采用带变频器的工质泵驱动.结果表明:室内温度25℃、室外温度10℃时,机组换热量随工质泵频率先增大后减小,在工质泵频率为35 Hz时达到最大值;能效比(energy efficiency ratio,EER)随工质泵频率初始变化不明显,然后逐渐降低.在室外温度为0~30℃时,实验获得了2种运行模式的性能变化情况和最佳转换温度.

To investigate operating characteristics of the pump-driven two phase loop integrated with the refrigerating system,especially the heat exchanging performance changing with pump frequency and temperature difference between indoor and outdoor,an experimental setup of the integrated refrigerating system was established. In this setup,a 2. 63 k W compressor and a 3. 75 k W compressor were used in the vapor compression refrigerating system,respectively. And an inverter pump was used in the pump-driven loop. Results show that the heat exchanging performance of the integrated system increases when the pump frequency is below 35 Hz,and then decreases with the frequency at the indoor temperature of 25 ℃and the outdoor temperature of 10 ℃,while the energy efficiency ratio changes slightly with the frequency in the beginning and afterwards decreases gradually. When the outdoor temperature varying from 0 ℃ to30 ℃,the variation tendency of the performance for the integrating system was investigated and the optimum outdoor temperature for switching the operating modes was obtained.