Research On Performance Test System Of Gas Turbine Driven Compressor Unit And Utilization Of Waste Energy In Long Distance Natural Gas Pipeline

In the long-distance natural gas pipeline,the gas driven compressor unit is the core equipment in the process of long-distance pipeline transportation,which has been imported for a long time.At present,the domestic 30 MW unit has been successfully developed.A performance test system is developed to directly output the unit efficiency and other important performance indicators,so as to provide reference for further optimizing the performance of domestic units.Waste energy utilization project is one of the key energy-saving projects in China.It can not only save energy but also reduce environmental pollution by using appropriate methods to recover this part of energy.Taking the domestic 30 MW units as the research object,a performance test system is developed,which can be used for remote monitoring,realtime display and historical operation analysis of the unit.The designed performance test program of gas driven compressor unit has been applied in the west-to-east gas pipeline project.The system can not only be used for the performance test of different gas driven compressor units,but also can be used for reference for other performance testing systems.Using Aspen HYSYS software simulates the Organic Rankine cycle to recycle the waste heat of compressor station flue gas in the temperature range of 400-500℃.Considering that the flue gas conditions vary over a period of time,it is proposed to take the average net output work in a period of time as the optimization objective to compare and analyze the cycle performance of benzene/R141 b,benzene/R123,toluene/R141 b and toluene/R123 as circulating working fluids,and compare the degree of waste heat recovery and utilization of single-stage,tow-stage series and tow-stage parallel Organic Rankine cycle is studied.The results show that benzene/R141b(0.3/0.7)as the working fluid of the two-stage parallel organic Rankine cycle has the best performance,whose output power is1490 kw,the average thermal efficiency is 21.20%,and the exergy efficiency is 47.21%.By using HYSYS software,the direct expansion power generation system,the direct expansion power generation and LNG production combined system,the expansion power generation and LNG production combined system with cooling before expansion and the expansion power generation and LNG production combined system with compressor are constructed for pressure energy recovery.From the perspective of thermodynamics,the comprehensive recovery rate of pressure energy is proposed as the optimization objective.The power generation capacity of process 1 is the largest,the comprehensive recovery rate of pressure energy of process 3 is the highest,and the temperature of LNG product obtained by process 4 is the lowest.According to the flow requirements of downstream pipeline network and the different demand of LNG products,different processes and flow distribution can be selected,which can provide reference for the actual needs of different regions.