| Gas-steam combined cycle(CCPP) power generation technology has a higherefficiency and Organic Rankine Cycle(ORC) can recover and reuse low-grade energy.Through the research on the integrated system which making two cycles coupled, thepower and the efficiency can further improve.Taking a350MW CCPP unit of Beijing Taiyanggong Gas Thermal Power Co.Ltd asexample and based on cascade utilization of energy, this paper proposes a program of gas-steam-organic combined cycle (GSOPP), Firstly, through the analysis of the thermalbalance and exergy balance models of CCPP, this paper makes Performance calculationand the exergy lost analysis of CCPP unit of Beijing Taiyanggong. Secondly, six organicworking mediums are screened and the influences of the evaporation temperature, thecondensing temperature, the evaporation pressure and the condensation pressure on theefficiency of the ORC are studied. Finally, based on design and operation parameters of the350MW units, this paper compares and analyzes the thermal economy between theextraction scheme and the exhaust scheme of GSOPP. It also optimizes the heat sourceparameters. The calculation shows that, on the basis of the positive energy coefficient,R141b is the best organic medium. Compared with the original process, under the designcondition, the generated power of extraction scheme can go up by14.76MW and theexhaust scheme can improve6.37MW. The generating efficiency can improve1.48%and0.47%.Studies have shown that, the extraction scheme of GSOPP can further improve thegenerated powe and generated efficiency of CCPP. The results can provide new ideas andsolutions for increasing the generated efficiency and load. |
