LNG 工厂冷剂压缩机一次性启动方案

1. 中国石化江汉油田分公司江汉采油厂湖北新捷LNG 项目部;2. 中国石油青海油田分公司;3. 中国石油北京油气调控中心

LNG 工厂;冷剂压缩机;启动;层次分析法

One-time start-up scheme of the refrigerant compressor in LNG plant
YANG Ye1, HE Linjun2, CUI Yue2, CHANG Liming2, DONG Caihong3, WANG Zhaobing2

1. Hubei Xinjie LNG Project Department, Jianghan Oil Production Plant, SINOPEC Jianghan Oilfield Company;2. PetroChina Qinghai Oilfield Company; 3. PetroChina Oil & Gas Pipeline Control Center

LNG plant, refrigerant compressor, start-up, analytic hierarchy process

备注

LNG 工厂冷剂压缩机多次启动将会造成物料损耗和环境污染双重问题,迫切需要对压缩机启动方案进行优化。以昆仑能源黄冈LNG 工厂为例,其乙烯制冷循环系统冷剂装填完毕后,需在压力上涨至设计值前立刻启机,否则压力过高,将导致压缩机启动负荷过大而启机失败,每次启机失败均需将系统压力释放至0.6 MPa 后方可再次尝试启动。根据2015—2017 年该厂乙烯压缩机多次启机数据,利用层次分析法进行数学建模。通过对比优选,提出了压缩机一次性启动方案:在压缩机处于2 200 r/min 低速运转期间,打开放空阀,充分冷却机体后再升速;在升速过程中,当入口温度低于-40 ℃、压力低于当前温度对应露点的压力、喘振阀开度调整至压缩机电流小于1 200 A时,保证机体不发生振动联锁和超负荷,从而一次性启机成功。该方案解决了压缩机反复启动问题,可为其他LNG 工厂科学开工提供借鉴。(图4表1,参[19]

Multiple start-up of refrigerant compressor in LNG plant can lead to the dual problem of material loss and environmental pollution, so it is in urgent need to optimize the start-up of refrigerant compressor. In this paper, the Kunlun Energy Huanggang LNG Plant was selected as the example. After refrigerant is filled in the ethylene refrigeration cycle system, the compressor shall be started immediately before the pressure rises to the design value, or the pressure will be too high, leading to the failure of compressor start-up due to excessive start-up load. And after each failure, the compressor shall not be started again until the pressure is released to 0.6 MPa. Based on multiple start-up data of the ethylene compressor in the Kunlun Energy Huanggang LNG Plant from 2015 to 2017, mathematical modeling was conducted by means of analytic hierarchy process. And by virtue of comparison and selection, the compressor one-time start-up scheme was proposed as follows. When the compressor is in the period of low-speed rotation (2 200 r/min), turn on the blowdown valve to cool the machine sufficiently, and then raise the speed. In the process of speed rising, when the inlet temperature is lower than -40 ℃, the pressure is lower than the dew-point pressure corresponding to the current temperature and the opening of the surging valve is regulated to the electric current of compressor less than 1 200 A, the machine suffers no vibration and interlock overload, and thus the one-time start-up succeeds. This solution solves the multiple start-up of compressor and provides the reference for the scientific operation start of other LNG plants. (4 Figures, 1 Table, 19 References)