Performance Of Gas Pressure Regulation System Based On Screw Expander

With the rapid development of the world,energy demands and environmental protection requirements are increasingly strong in China,the consumption proportion of natural gas,which as a kind of primary energy is increasing.The consumption of natural gas in China is increasing year by year,and the construction of natural gas long-distance pipelines are also developing rapidly.High-pressure natural gas delivered to the users from the gas source after multi-stage pressure regulating process.There is a lot of pressure in the traditional natural gas pressure regulating process can be wasted,because of the principle of using throttling and depressurizing.This paper proposed a single-screw expander(SSE)natural gas regulating power generation system.The system can complete the whole process of natural gas pressure regulation,and at the same time,it can also use pressure energy to generate electricity effectivelyWith the help of the SSE developed by Beijing University of Technology independently,this paper built a SSE power generation experimental platform using dry compressed air as the air source.This paper introduced the selection,arrangement and connection of each component in the experiment system,and discussed the problems and solutions of the system in operation.The measurement errors of each component were analyzed to ensure the accuracy of the data.Under condition of different inlet pressure,some tests were done for the SSE was as follow:the relationship between output power and speed and air flow;the relationship between temperature difference and speed of SSE and air flow.In this paper,the solar power SSE natural gas regulating power generation system was put forward,and the low temperature natural gas was heated by the solar energy.Through thermodynamic analysis of the system,including the energy balance and exergy analysis of the system equipment,and to get the power generation efficiency and exergy efficiency of the system.The system thermodynamic formula was compiled and calculated using EES software.For the small flow system,the solar energy can meet the demand of natural gas return heat,and the residual heat can be used for heating or living hot water.By set up the solar radiation intensity test bench,record the intensity of direct solar radiation at local time.and the gas flow data of one residential building,Through to the compilation and calculation of the system,we can get the system heat storage tank volume was 5 m~3.When the inlet gas pressure was 0.7 MPa,outlet gas pressure was 0.1 MPa,inlet gas temperature was 25℃,it was compiled by calculation.We can get:the exergy efficiency increased with the inlet flow rate of the heat exchanger,expander and generator.When inlet flow rate of system was 350m~3/h,the exergy efficiency of heat exchanger was 20%;the exergy efficiency of expander and generator was 23.22%.When the inlet gas pressure was 0.7Mpa,outlet gas pressure was 0.1 Mpa,inlet gas temperature was 25℃,Using the data of the change of natural gas flow in a residential building on December 01,2016,the solar radiation intensity change data measured on December 01,2017,it was compiled by calculation,we can get:the maximum power generation efficiency was 19.3%;the maximum exergy efficiency of the system was 16.7%.This paper proposed using of solar energy heat the low temperature natural gas.When the inlet gas pressure was 0.7 MPa,export gas pressure was 0.1 MPa,inlet gas temperature was 25℃,the outlet gas temperature was 5℃,the inlet gas temperature of heat exchanger was-7℃,the outlet gas temperature of heat exchanger was 5℃,if we used the gas boiler to heat the low temperature natural gas,the inlet gas flow rate was 300 m~3/h,supplied gas ten hours one day,we can get the gas consumption for a year was 620m~3.Through the experimental research and theoretical analysis,the independent SSE gas regulating power generation system can be obtained on the basis of the realization of natural gas pressure regulation,using the high pressure gas to generate electricity,and the energy utilization rate can be improved by using solar energy to heat the low temperature gas.