永磁变频螺杆制冷压缩机变工况运行特性试验研究

Investigation on theperformance of VFD twin-screw refrigeration compressor for air conditioning system

为有效提升螺杆制冷压缩机全工况运行效率,研制搭载大扭矩宽负载永磁电机的变频可变压比螺杆压缩机,针对冷水机组高权重运行工况,试验研究压缩机在不同工况不同转速下的运行特性.结果表明不同工况下压比适应性调节后,均存在使压缩机效率最高的最佳运行转速,且最优转速随着外压比的升高而增大.依据机组综合能效(IPLV)的满负荷、部分负荷能效权重和工况要求,提出压缩机综合绝热效率(IPLE)最优的设计方法.当压缩机满负荷转速设计值为4200rpm时IPLE最高,达到0.773.永磁变频压缩机应用于水冷机组时,相比于定频螺杆机组,IPLV提高35.2%;相比于磁悬浮离心机组,IPLV提高11.9%.

To improve the efficiency of the screw refrigeration compressor under integrated operating condition,the variable speed screw compressor with permanent magnet motor is developed,and its pressure ratio is also variable. Considering the weight of operation conditions of chillers,the operating characteristics of the compressor at different speeds and in different operating conditions are experimentally studied. The results show that,after the adjustment of pressure ratio the optimal operating speed,which makes the compressor most efficient under different operating conditions,increases with the raise of the external pressure ratio. According to the chillers’ Integrated Part Load Value (IPLV) requirement,the optimal design method for compressor’s Integrated Part Load Value Efficiency (IPLE) is proposed. When the compressor’s full load speed is designed to 4 200 rpm,the IPLE which reaches 0.773 is the highest. When the permanent magnetic variable frequency compressor is used in water-cooled chiller,IPLV is 35. 2% higher than the fixed-speed screw unit,and 11.9% higher than the magnetic levitation centrifuge unit.