大型空气压缩机变工况性能试验研究

An Experimental Study on Off-design Performance of Large-scale Air Compressor

压缩空气储能系统压缩机受系统自身特性影响,长期处于变工况运行状态。对某多级压缩空气储能系统大型空气压缩机变工况条件下级间性能开展试验研究,即利用压缩机管网特性试验平台,开展排气压力6.5~9.5MPa范围试验测试,对压缩机各级吸气和排气压力、吸气和排气温度、压缩机排气量、电机电流、电压等参数进行实时采集。通过对压缩机实时变工况下各项参数分析,具体研究压缩机的容积效率、循环指示功率、等温效率、各级压比分配和各级压损随出口负荷变化而变化的规律。研究结果表明:压缩机的容积效率基本不随工况的变化而变化,平均为0.96;循环指示功率随出口负荷的增加而增加;压缩机的多变效率从74.02%上升到78.14%,多变效率随着排气压力的增加而增加;低压级压比增大速度较快,易达到额定状态,高压级压比达到额定状态较缓;一~四级的相对压力损失基本保持不变,五级出口排气到集气汇管的相对压力损失随着出口负荷的增大而减小。

The compressor of compressed air energy storage system has been under off-design conditions for a long time as affected by its own characteristics.In this paper,the inter-stage performance of a large-scale air compressor in a multi-stage compressed air energy storage system under off-design conditions is studied,i.e.,using the characteristic test platform for compressor pipe network to carry out experimental test of dis-charge pressure from 6.5 MPa to 9.5 MPa.The parameters of compressor such as suction and discharge pres-sure,suction and discharge temperature,air displacement,motor current and voltage are collected in real time.Through the analysis of the parameters of compressor under real-time off-design conditions,the change rules of volumetric efficiency,cycle indicated power,isothermal efficiency,pressure ratio assignment at each stage and pressure loss at each stage with the change of outlet load are studied.The results show that the volu-metric efficiency of compressor,with an average of 0.96,basically does not change with the change of working conditions,the cycle indicated power increases with the increase of outlet load,the polytropic efficiency of compressor increases from 74.02% to 78.14% with the increase of discharge pressure,the pressure ratio at low pressure stage increases quickly and easily reaches the rated state while the pressure ratio at high pres-sure stage reaches the rated state slowly,and the relative pressure losses at the first to the fourth stages basically remain unchanged while the relative pressure loss from the outlet to the gas header at the fifth stage decreases with the increase of outlet load.