Establishment Of Water Temperature Prediction Model And Calculation Of Dynamic Parameters For Surface Water Source Heat Pump System

Surface water source heat pump system is widely used in the field of central air conditioning because it can greatly reduce energy consumption.However,the performance coefficient,energy consumption and heat carrying capacity of units in surface water source heat pump system are all affected by the external environment.Therefore,it has theoretical significance and practical value to study the fluctuation law of these parameters with the external environment.In this paper,the heat transfer mechanism of water used in surface water source heat pump system is studied,and the heat transfer from the water to the atmosphere and the soil is analyzed.By using statistical method,a more accurate water temperature prediction model is obtained,and the influence degree of water temperature at the outlet of different load side of surface water source heat pump system on unit operation is further analyzed.On-site monitoring parameters,such as air dry bulb temperature,water temperature at inlet and outlet of lake water source heat pump unit and unit operating load,show that there is a linear relationship between daily average lake water temperature and daily average air dry bulb temperature.Under partial load conditions,different air dry bulb temperatures correspond to different partial load rates,which will directly affect the unit operation.The inlet water temperature on the water source side changes with the temperature,while the outlet water temperature of the load side does not change much in one day with the change of the temperature.Using the above water temperature prediction model,the dynamic unit performance coefficient is fitted,and the dynamic heat carrying capacity calculation model is deduced.In the cooling and heating seasons,the deviations between the measured and predicted values of COP are 2.013%and 3.670%,respectively;the deviations between the measured and predicted values of unit energy consumption are 3.3%and 0.7%respectively;and the average maximum heat carrying capacity of lake water is 31.2 W/m² and 37.5 W/m²,respectively.The application of lake water source air conditioning system is analyzed from the aspects of economy,energy saving and environment.Compared with traditional air conditioning system,the annual total cost can be reduced by 25.38 million yuan;the annual energy consumption can be saved by 68.8%;and the discharge of pollutants such as CO₂,SO₂,NO_x,smoke,slag and so on can be effectively reduced,which also plays a role in purifying water quality.