The Research On Deterioration Diagnosis Of Energy Efficiency For Heat Pump

The heat pump unit is the most primary component of energy consumption of theheat pump system. While authors find that the phenomenon that energy efficiency ofheat pump unit isn’t high like we think is universal. Why is the energy efficiency ofheat pump unit not high? This question must be answered to save energy consumptionof building air conditioning system, and to keep the heat pump unit working on highenergy efficiency. So this paper focuses on the research on deterioration diagnosis ofenergy efficiency for heat pump unit.Firstly, according to the first law of thermodynamics and the analysis about heatexchange between water and refrigerating fluid, this paper takes empirical value as thereference value and develops the model of fast deterioration diagnosis of energyefficiency for heat pump unit. Applying this fast diagnosis model to there actual projectcases, this paper diagnoses the deterioration of energy efficiency of these heat pumpunits successfully. According to experience collecting date in field and technicaldemands measuring basic parameters, this paper presents the method collecting date infield and the criterion of date collection validity, which is the base of deteriorationdiagnosis of energy efficiency for heat pump unit.The characteristic parameters of the degradation of energy efficiency for heatpump comprise these characteristic parameters representing the degradation of energyefficiency of the components for heat pump. This paper uses combined efficiency andvolume efficiency to represent efficiency of compressor, and uses heat transfercoefficient to represent heat transfer efficiency of condenser and evaporator. Based onenergy equation, basic heat transfer equation and the correlation formulas to calculate the heat transfer coefficient, the mechanism model of thermodynamic calculation oftheoretical cycle was built. According to analyze the difference between actual cycleand theoretical cycle, the black-box model of thermodynamic calculation of actualcycle was built. In order to find out the degree that these characteristic parametersimpact the energy efficiency of heat pump unit, this paper mainly analyzes thevariation of characteristic parameters according to PLR and how these characteristicparameters affect energy efficiency of unit and power consumption of compressor byapplying the models to a actual water source heat pump unit, which is must be done todiagnose the deterioration of energy efficiency for heat pump unit. According to themodels of thermodynamic calculation of theoretical cycle and thermodynamiccalculation of actual cycle, this paper presents the model and method of deteriorationdiagnosis of energy efficiency for heat pump unit. According to apply this model to aactual project case, this paper diagnoses the energy efficiency of the heat pump unitsuccessfully.