Research On LNG Vaporization System Based On Solar Heat Pump

Since the "13th Five-Year Plan" of energy sources,it has become the current research scholars' focus on energy and environmental problems,which China faces now.They cautious on the development of renewable energy resources,strengthen economic and environmental protection,and adjust the demand for energy structure.In order to realize the complementary use of energy,this subject proposed and conducted a theoretical study of a LNG vaporization system based on solar heat pump and air-temperature vaporizer,which aimed to provide some theoretical reference and guidance for the popularization of solar heat pump applications and to improve the vaporization capacity of air-cooled vaporizer.Firstly,based on the domestic and foreign dates of direct-expansion solar assisted heat pump and LNG air-temperature vaporizer,this paper put forward a LNG vaporization system based on solar heat pump,and the working principle of this system was introduced in the aftermath.According to the intensity of solar radiation,the operating conditions of this system were divided into conventional direct-solar heat pump form and air-source heat pump.And then,the system was designed and configurated.Secondly,the mathematical model of collector / evaporator,compressor,air condenser and expansion valve is established by lumped parameter method.And then,discussed and established the mechanism and model of air side,which ranged from dry conditions,condensation conditions and frost conditions under forced convection condition.Lastly,the LNG vaporization process were divided into three sections according to the bubble point and dew point,which mean liquid zone,two-phase zone,and gas zone,meanwhile,the heat transfer model of each phase section was established.Finally,the thermodynamic performance of the DX-SAHPNV system under typical annual meteorological parameters of Beijing was analyzed by Matlab simulation.The average annual COP of the system was 4.45,and the average heat collection was 1.23,which was 17.72% and 12.84% higher than the conventional DX-SAHP respectively.In addition,the average natural gas output from AAV in winter and summer increased by 3.31 K and 7.46 K,respectively,which effectively reduced the switching frequency of AAV and improved the AAV gasification effect.Afterwards,this paper investigates the influence parameters witch caused bay DX-SAHP system,such as the air supply temperature,air supply speed,relative humidity and LNG temperature and flow at the entrance of AAV.