| Water source heat pump technology became one of the most widely used way inbuilding heating and air conditioning, because of its high efficiency and energy savingin operaton, and environmental protection. However, in the practical application,single source heat pump exist their outstanding problems. For example, the systemperformance coefficient of the sea water source heat pump is too low when theSeawater temperature is too low. There is even the danger of icing happened. Theunderground water source heat pump exist the problem that the water consumption istoo large, pump power is too high and the heat unbalance. In recent years, thecomposite source heat pump system which combined with the characteristic of singlesource heat pump, cause more and more attention by the researchers, because of itshigh operation efficiency in energy comprehensive utilization.This paper according to the meteorological characteristics of the Tianjin coastalarea and the sea water resources condition, put forward a composite source heat pumpsystem using ground water and sea water. On the basis of that the research of thispaper are as follows:This paper established the simulation model of water source heat pump unit,including compressor mathematical model, expansion valve mathematical model,condenser mathematical model and evaporator mathematical model. Then this paperverify the accuracy of the models by using of actual engineering experiment.According to the ground water–sea water composite source heat pump systemin tianjin port, this paper optimized the operation strategy of the ground water–seawater composite source heat pump system and selects the optimal operation strategy.In heating season, the composite source heat pump system has two kinds of operationmodes include the scheme heating by seawater heat pump separate and the schemeheating by groundwater heat pump separate. In cooling season, the composite sourceheat pump system has two kinds of operation modes include the scheme cooling byseawater heat pump separate and the scheme cooling by seawater heat pump andgroundwater heat pumpBy using the orthogonal experimental design method, calculated the totaloperation maintenance cost in different operation strategy, then determined the best operation strategy. In heating season, when the seawater temperature is higher than8℃, using the seawater source heat pump heating single, using ground water sourceheat pump heating in other time. In cooling season, when the seawater temperature islower than26℃, using the seawater source heat pump cooling single, using the seawater source heat pump and ground source heat pump combined cooling. The waterpump in the heat source side use frequency conversion adjustment, adjusted flowaccording to the load ratio. The load assigned to each unit average when many unitsrunning at the same time.The paper based on the annual cost value analysis method at last, considering thetime value of money, comparing this composite source heat pump system and theconventional air conditioning system. The conventional air conditioning systeminclude integration of direct-fired machine, ground source heat pump, sea watersource heat pump and gas boiler, and underground water source heat pump. Thispaper discussed the economic benefits and environmental benefits of this system, andmake foundation of promoting this ground water–sea water composite source heatpump system being using in coastal areas. |