Study On The Thermal Characteristics Of Building Integrated Falling Film Cooler And Coupling Characteristics With Ground Source Heat Pump

As an alternative to traditional air conditioning systems,soil source heat pump systems(GSHP)are gaining more and more attention.However,for buildings with predominantly cold loads in hot summer and cold winter regions,long-term operation of soil source heat pumps will lead to soil heat imbalance,and cooling towers as an auxiliary cooling source coupled with soil source heat pump systems can effectively solve this problem.However,the cooling tower is noisy,occupies space and affects the aesthetics of the building.Therefore,it is of great practical significance to propose an integrated falling film cooler with the building,study its thermal characteristics and couple it with the soil source heat pump system as an auxiliary cooling source for the practical application of the coupling system of falling film cooler and soil source heat pump.In this thesis,a study on the thermal characteristics of a falling film cooler integrated with a building is carried out by various research methods,including theoretical analysis,experimental verification and numerical simulation.The numerical model of the integrated falling film cooler with the building is established by CFD technology.Through Fluent-TRNSYS co-simulation,an inter-seasonal cooling storage simulation model with annual unit is established by coupling the falling film cooler with the soil source heat pump system in the TRNSYS system simulation platform.The main elements are as follows:(1)The cooling principle of the falling film cooler is described,an integrated falling film cooler with the building is proposed,an engineering-scale experimental system of the integrated falling film cooler with the building is built,and the experimental system operation scheme is determined.Experimental data during the nighttime operation of the falling film cooler are plotted and analyzed.(2)The heat transfer model of the falling film cooler is established,the mathematical model related to the numerical simulation of the cooler is introduced,the numerical model of the falling film cooler integrated with the building is established,and the steady-state solver is used for the solution calculation.The reliability of the established numerical model is verified by comparison with experimental data,and the effects of cooler inlet mass flow rate,cooler area,outdoor wind speed and outdoor air humidity on the heat transfer effect of the falling film cooler are analyzed.(3)Based on a small independent building in Xuzhou area,a new coupling system of falling film cooler and soil source heat pump is proposed by coupling the falling film cooler as an auxiliary cooling source with the soil source heat pump system.The simulation model of the coupled system of falling film cooler and soil source heat pump is built in TRNSYS simulation platform through Fluent-TRNSYS co-simulation.The established system model is simulated for ten years of operation,and the average soil temperature,buried pipe inlet and outlet temperature and unit COP operation data are obtained.And by comparing and analyzing with the operation data of single soil source heat pump system,it is verified that in the hot summer and cold winter areas the cooling film cooler as an auxiliary cooling source coupled with the soil source heat pump can effectively suppress the soil temperature rise and guarantee the long-term stable and efficient operation of the heat pump unit.