The Research On A New Air-condition Systerm By Using LNG Cold Energy

As fast development of our country’s economy, demand for energy rapid growth,environmental pollution index is higher with demand for energy growingrapidly.Therefore, in order to achieve sustainable development and improve the ecologicalenvironment, natural gas, with its high efficiency、energy saving and wide applicationadvantages is adapted to the demand.The liquefied natural gas (LNG) is stored in condition of112K temperature and0.1Mpa pressure, only1/600of the original volume, easy to transport. Natural gasliquefaction is a process of high energy consumption, about costing840KWh energy perton, so it contains great cold energy. Use the cold exergy when LNG vaporised intraditional air-conditioning, which not only saves energy of air-conditioning,but alsoreduces the power consumption of mechanical refrigeration, having considerableeconomic benefit and social benefit, meanwhile it becomes the leading edge of theweather research and hot issue in liquefied technology.This paper summarizes main ways of using LNG cold energy, which using the mostextensive is to generate power, and briefly summarizes several circulation of recoveringLNG cold energy, due to mature technical, with broad application prospect. Because LNGis a mixture, who has more complex thermal physical. It’s known to reach higher thermalefficiency must select suitable laser by the way of thermal physical research. Through thesimulation of HYSYS software and relevant literature, choose the suitable workingmedium, making a more efficient circulation. But LNG gasification temperature range isbroad, if just using one cold temperature region will cause the energy to waste. Based onthe recovery of physical exergy of cold available during the regasification of LNG, a newutilization of LNG cold exergy in an air-conditioning system is proposed, on the one hand,generate power, on the other hand, use LNG cold energy in traditional air conditioning,which both saved the air conditioning of energy, and solves the problem of LNG vapors.Through reseaching low temperature Rankin circulation system characteristics, includingbasic parameter selections, conduct simulation with chemical software-HYSYS and do exergy efficiency analysis from the quantity and quality, All aspects of energy use in thesystem is obtained by calculating exergy efficiency and exergy loss. To the net work fromrecovery of LNG cold energy and the system total exergy efficiency for thestandards,combining with hot fluid and cold fluid temperature curve in heat exchanger,find out the greatest exergy loss exists in the heat exchanger. Based on the process makingimprovement and innovation, compared to original process, is more efficient.