Research On Cold, Heat And Power Cogeneration Technology Of LNG Satellite Station

In recent years,with natural gas import increasing constantly,the liquefied natural gas(LNG) industry has developed crazily in China,there are constructed numerous LNG vaporizing station and LNG satellite station rapidly,resulting that research on LNG cold energy utilization becomes more fast.At present,the researches of LNG cryogenic energy utilization mainly aim at the coastal LNG vaporizing station.while studies on LNG satellite station are less. It has strict demand for site selection of LNG satellite station,when choosing the seawater or industrial waste heat as high temperature heat sources;in addition, it causes overlarge collector heat plate and unstable heating, when only choosing solar energy resources as high temperature heat sources.Besides, the air conditioner lack of heating supplyment also is a problem.So it's proposed a new Cooling Heating & Power process for LNG satellite station,including the LNG cold energy recycling technology,steam cycle power technology,air source heat pump assisted solar energy heating technology.The main innovations as following:1) Taking full advantage of the abundant solar energy resources and high temperature in summer,improving the efficiency of the steam power cycle,and reducing the pressure of the summer peak;2) Air source heat pump not only resolves the instability of solar energy resources,but also provides the high temperature heat source for air conditioner in winter; 3) Using the ice and heat storage technology,achieving peak load shifting;4) Setting working fliuds preheater, making full use of the environmental heat sources,reducing the heat-making cost as well as easy controling.By LNG cold exergy characteristics and working fluid characteristics analysis and combined with the technological requirements,determine the R1270 as steam power generation cycle working fluid heat exchangers, water as Thermal storage medium.Depending on the ambient temperature,the run-time process will be divided into cooling season,low season, transition season.With Aspen HYSYS simulating and optimizating process parameters,it can be found that both temperature and pressure of working fluid in turbine turbine inlet have a significant influence on power generation cycle efficiency:as a certain pressure,the higher the temperature of working fluid,the more power generation efficiency;At a certain temperature,the higher working fluid pressure, the more power generation efficiency firstly,while reaching dew-point pressure,getting maximum, then decreased sharply.With simulation analysis of the solar radiation intensity and ambient temperature solar heating effect by TRNSYS,the results showed that the higher solar radiation intensity and increasing ambient temperature caused the greater the solar fraction collector and collection efficiency. Too low environment temperature caused low solar heating effect.In order to use high temperature and solar radiation in summer as well as avoid low temperature and high-cost heat pump heating in winter,the process of heating temperature takes quarter measures that appropriate improved summer heating temperature and decreased the temperature of heating in winter.Considering seasonal variations in solar energy resources,it's located in the cooling season, low season, the transition seasons,air source heat pump heating capacity accounts 20%,60%,40%,of total heat demand respectively,then calculating the air source heat pump system energy consumption.Through the calculation on power generation efficiency and heat pump system cost,this paper gets each comprehensive economic benifit,the results showed:at amount of LNG gasification 2,6,10,14,18, 20×104Nm3d-1.Based on a given industrial electricity unit price the net annual economic benifit were about 121,100RMB,36,6000RMB respectively,60,6900 RMB,89,0100 RMB,1.0925millionRMB,1.2134 million RMB.The technology economic benefit is obvious.In summary,the new LNG satellite station CCHP technology not only well offsets the underutilized cold energy in LNG satellite station,but also takes full advantage of abundant solar energy resources,achieving the CCHP and obtaing optimum economic benefits.