CNG压缩机节能技术与试验分析

An experimental study of technical measures for energy saving of CNG compressors

压缩机是CNG加气站的主要耗能单元,但目前我国CNG技术起步较晚、研究不够深入,导致CNG加气站工艺流程不尽合理、CNG压缩机整体性能不够优良,系统运行能耗高、效率低。为此,针对CNG压缩机效率低、能耗高的问题,开展了压缩机能耗影响关键参数分析和节能技术研究。结合CNG压缩机工艺提出了对压缩缸级间回气进行冷却、分离的节能技术改造方案,完成了L-12/5-250型CNG压缩机第二、四级级间回气管线加装冷却器的节能技术改造,并进行了系统的现场能耗测试。在不改变冷却系统和CNG压缩机系统其他设备及参数的条件下,对比测试了原料气进气压力分别为0.35、0.38、0.40MPa时关闭和开启第二、四级级间冷却器工况下压缩机的运行参数和能耗数据,得到对应节能比分别为3.87%、4.04%、3.96%,节能效果良好,验证了该节能改造技术的可行性。

For lack of intensive studies and advanced techniques, unreasonable flow process and poor performance of CNG compressors have resulted in high energy consumption and low working efficiency, which have restricted the development of CNG filling stations in China. In view of this, this paper aims to study how to improve the efficiency and reduce the energy consumption of a CNG compressor, which is the most energy consumption unit of a CNG filling station. Thus, a study was made on what key parameters have impact on the efficiency of a compressor and what technical measures should be taken. Based on the compressing process, the transformation schemes were presented of cooling and separating the return gas between the stages of pipe loops. In a pilot test per- formed on an L-12/5-250 compressor, a cooler was installed in the intersage line between the second and the fourth pipe loops and the evaluation test was also made subsequently on the energy saving effect. Only when the intake pressure of inlet feed gas was adjusted at 0.35, 0.38, 0.40 MPa respectively and with no any other changes ever done on the same compressor, the operating parameters and energy consumption data were recorded and compared between two working conditions when the installed cooler was on and off. As a result, the energy consumption of the compressor with the cooler on was saved by 3.87%, 4.04%, 3.96% accordingly, which verifies the feasibility of the above transformation schemes.