天然气压缩机组效率不确定度评定研究

Research on Efficiency Uncertainty Evaluation of Natural Gas Compressor Unit

为了提高气田天然气压缩机组的节能监测水平,以某气田增压站ZTY470整体式天然气压缩机组为研究对象,使用蒙特卡洛法和GUM法分别评定压缩机组的效率不确定度;应用蒙特卡洛法的评定结果,对GUM法进行适用性验证;通过蒙特卡洛局部敏感性分析,确定压缩机组效率测试模型中各输入参数对效率不确定度的影响。结果表明:蒙特卡洛法计算压缩机组效率为22.4%,效率标准不确定度为0.9%,概率95%的包含区间为[20.8%,24.1%];由于压缩机组效率测试模型的非线性特征,GUM法未通过蒙特卡洛验证;进出口压力对机组效率不确定度的影响最大,燃料气流量的影响次之,压缩天然气流量的影响较小,大气压力、天然气进出口温度和压缩因子对机组效率不确定度的影响极小,可忽略不计。

In order to improve the energy-saving monitoring level of the gas field natural gas compressor unit,ZTY470 integral natural gas compressor unit in a gas field booster station was taken as the research object.Based on Monte Carlo method and GUM method,the uncertainty of compressor unit efficiency is calculated.At the same time,the feasibility of GUM method is verified by Monte Carlo method,and the influence of each input on the uncertainty of compressor unit efficiency is determined by Monte Carlo local sensitivity analysis.The results show that the efficiency of compressor unit calculated by Monte Carlo method is 22.4%,the uncertainty of efficiency standard is 0.9%,and the probability 95%coverage interval is[20.8%,24.1%],and due to the nonlinear characteristics of the efficiency measurement model of compressor unit,the GUM method has not passed the Monte Carlo verification,and the inlet and outlet pressures have the greatest impact on the unit's efficiency uncertainty,followed by the fuel gas flow,and the compressed natural gas flow has a smaller impact.The impact of the remaining measurement parameters of atmospheric pressure,natural gas inlet and outlet temperature and compression factor is negligible.