Application Study Of Waste Heat Recovery For Power Generation From The Gas Turbine Based On Organic Rankin Cycle

The problems of high intensity,high emission,high pollution,low quality and low efficiency in the way of energy utilization in China are puzzling the economic development of our country.Therefore,the energy conservation work has been widely valued by our government and the community.Under the background of global green economy,waste heat of low temperature power generation technology is a kind of energy conservation technology for recovering energy of waste heat of low temperature.Nearly 100 years,using organic fluid at low temperature shows a variety of advantages in the scene of the Rankine cycle.It attracts the attention of governments and energy workers in the world to study continuously.According to the organic Rankine cycle(ORC)working principle and thermodynamic calculation,the mathematical model is established for the condenser,evaporator,expander,working fluid pump,circulating pump,power generation and thermal efficiency of the ORC cycle,and energy loss of the whole system is analyzed.On the basis of this,according to the parameters of the working fluid,such as the critical parameter,the freezing temperature,the normal boiling point,etc,as well as flow performance,the heat transfer performance,the environmental protection performance,the chemical property of the working fluidand so on,the system selects R245fa(five fluorine propane)as the circulating working fluid.In this paper,the research of PG6561B type gas turbine and combined cycle thermal system,through the analysis of the system,proposed the use of organic Rankine cycle(ORC)power generation technology to reduce the exhaust gas temperature of gas steam combined cycle unit waste heat boiler,so as to achieve the depth of flue gas waste heat utilization,to improve the utilization of waste heat.According to the exhaust gas parameters and the original data of the project,the design parameters of the ORC power generation system are determined.By means of mathematical model,through MATLAB programming,and REFPROP 9.1 database mount into the model,the system is calculated and analyzed.Comprehensive the analysis of the thermal efficiency,the net power,energy efficiency indicators and two systems of energy loss,the results show that the overall performance of quasi trilateral cycle systemis better than ORC system.In this paper,the heat transfer area(APR)required for the unit net work in quasi trilateral cycle system is calculated and analyzed.When the evaporating temperature is between 95?and 110?,the APR is stable at the lowest value of 6m~2/kW.Using the method of economics,the author makes an optimal choice of the project by the calculation and analysis of the three indexes of the payback period,the internal rate of return and the net present value.Through analysis and comparison,the design value of the evaporation temperature can be selected between 100?and 110?,which can be combined with the risks and benefits in the course of the project practice.When the gas steam combined cycle system is combined with quasi trilateral cycle,the thermal efficiency of the system is increased from 60.5%to 61.24%when the evaporation temperature of quasi trilateral cycle is 100?,which is increased by 0.74 percentage points.The overall thermal efficiency of the system has improved,but the increase is limited.