BOG压缩机进气加热及对流量影响的理论分析及实验验证

Theoretical Analysis and Experimental Verification on Suction Heating and Its Effect on Flowrate of the BOG Compressor

BOG压缩机是处理LNG储罐中闪蒸气(BOG)的关键设备。建立了有限元计算模型,得到了压缩腔壁面的稳态温度场,并以此为边界条件,采用动网格技术,模拟了进气过程中气缸内流场分布和温度分布。并搭建了试验台对理论模型进行了验证。结果表明:当BOG压缩机运行稳定后,其温度整体呈现由缸盖到曲轴箱单向递增的变化规律。温度系数随着进气温度降低而下降,进气温度低于-120℃时下降剧烈,高于-70℃后则趋于平缓。

Boil-off gas （BOG） compressor is the most important equipment for handing the boil-off gas of the liquefied natural gas （LNG）.In this paper,the FEM simulation of heat transfer in a BOG compressor ＂was performed,and the temperature fields of the cylinder were obtained.On this basis, using the solid temperature field as the thermal boundary condition, a CFD model with dynamic mesh was established to calculate the flow and heat exchange inside the working chamber.In order to verify the theoretical model, a performance test rig was built.The results showed that the temperature of compressor components from the cylinder head to the crankcase increased progressively when the compressor internal heat transfer was stable.The temperature coefficient tended to de-crease with the decrease of the suction temperature,with a dramatic decrease under the suction temperature lower than-120℃ and a slower decrease under the suction temperature higher than-70℃.