LNG 接收站高压泵增加叶轮后的性能变化及影响

1. 中国石化青宁天然气管道分公司;2. 中国石化青岛液化天然气有限责任公司

LNG 接收站;高压泵;压力;叶轮;性能曲线

Performance change and influence of high-pressure pumps after being added with impellers
YUAN Zhichao1, DONG Shun2, XUE Jixin1, XIA Shuo2, WANG Jiankun2

1. SINOPEC Qingning Natural Gas Pipeline Company; 2. SINOPEC Qingdao LNG Co. Ltd.

LNG terminal, high-pressure pump, pressure, impellers, performance curve

备注

随着中国天然气需求量的爆发式增长,LNG 接收站外输管道里程不断增长,出站压力随之持续增高,对压缩机、高压泵等设备性能提出了更高要求。以青岛LNG 接收站为例,针对外输压力的变化,提出对其4 台高压泵增加4 级叶轮的改造方法,并对改造后外输高压泵的性能变化及其对LNG 接收站工艺运行的影响进行研究。通过对改造后的高压泵扬程、轴功率、效率随着流量增加的变化趋势进行现场测试,结果表明:高压泵增加叶轮后,其扬程、轴功率、效率、电流均显著提高,其中3 台高压泵的运行参数可满足LNG 接收站现场实际需要,另外1 台即使在相同的测试条件下出口压力仍明显偏低;气化器、HIPPS(High Integrity Pressure Protective System)系统、外输管道高报压力及联锁值均需随之上调,接收站高压区连接法兰出现了多处泄漏,应加大巡检频率和力度;当LNG 接收站高压泵性能不同时,在运行过程中应该尽量选用性能相近的泵。研究结果可为高压泵的国产化设计、制造提供参考。(图4表2,参[20]

With the explosive growth of natural gas demands in China, the exporting pipelines of LNG terminals get longer and longer and correspondingly the outbound pressures also get higher and higher continuously, which requires more strictly on the performance of compressors and high-pressure pumps. In this paper, the Qingdao LNG terminal was taken as an example. In view of the change of its exporting pressure, it was proposed to transform its 4 high-pressure pumps by adding four-stage impellers. Then, the performance change of the exporting high-pressure pumps after the transformation and its influences on the process operation of the LNG terminal were analyzed. Finally, the change trends of the head coefficient, shaft power and efficiency of transformed high-pressure pumps with the increase of flow rate were tested on site. It is indicated that after high-pressure pumps are added with impellers, their head coefficient, shaft power, efficiency and electric current increase significantly. The operating parameters of 3 high-pressure pumps can satisfy the on-site actual demands of the LNG terminal, and the outbound pressure of the rest one is significantly low even under the same test condition. In this instance, the gasifier, the HIPPS system, the high pressure of exporting pipeline and the interlock value shall be increased correspondingly. In addition, leakage occurs frequently at the connection flanges in the high pressure zones of the LNG terminal, so it is necessary to enhance the inspection frequency and strength. When high-pressure pumps at the LNG terminal are different in performance, the pumps with similar performance shall be selected as far as possible in the process of operation. The research results can be used as the reference for the localized design and manufacture of high-pressure pump. (4 Figures, 2 Tables, 20 References)