The Character Analysis And Program Design Of Lake Water-source Heat Pump System

The fundamental basis of thermal equilibrium of the mathematical model in this paper is energy conservation. According to the characteristics of engineering project, a kind of program design and estimate software which include subsystem such as energy consumption model of heat pump unit, open-type and close-type piping dynamic model, pipe coil design model, eulimnetic thermal capacity analytical model, total energy saving rate model of lake source heat pump system compared with traditional air-conditioning system has been exploited. With C# language programming, the analysis of dynamic energy consumption and coefficient of performance of heat pump unit under natural and on-load conditions are within our reach.First and foremost, the software began with overall system design, including systematic structure and functions, analyzing the development method, platform and needed programming tools. Secondly, specialty function designs were conduced in heat pump unit and piping subsystem respectively. At last, we tested and verified eulimnetic thermal capacity and hypothetical cooling capacity in order to evaluate the comprehensive performance and implementary feasibility of heat pump system projects.With the system design and operation being tested in open-type and closed-type lake water heat pump system, this paper proved the practicability of design and estimate of lake water source heat pump software. Under the operational performance measurement, the statistics data of closed-type system on the base of a lake water source heat pump system project in shanghai, shows that the average coefficient of performance of heat pump unit is 3.61 when the average water inlet temperature at 8.1 Celsius degree. Leading in year-round building load calculated by DeST software, in view of using lake water source heat pump system compare with traditional hydrocooling unit assist furnaces system to analyze the energy consumption of AHU, piping and total system by our software respectively.A lake water source heat pump system project of comprehensive buildings in Chongqing is used for verifying the open-type operating mode under constant flow or variable flow conditions respectively in winter, compared mutual energy saving differences. The theory outlined in this article, via software simulated two kinds of working conditions, indicates that variable flow operation decrease the total energy consumption by 20.62% at part load. Water piping system with variable speed controlled not only has important economical potential but also possesses energy saving potential as much as 40.45%.The static water energy balance depends mainly on the balance beteewn some parameters such as solar radiate heat gain, water surface evaporation consumption and longwave radiation heat consumption at night. Actually, these equilibrium process spontaneously occured mainly on the surface of shallow water, and those available cold water at the bottom of reservoir was restricted by the depth and area of the superficial layer. Along with operation of the pump unit, thermal stratification of waterbody will be destroyed when quantity of heat raising little by little, which cause the overall temperature rising gradually. This thesis established an annual temperature model of static water lake that used for predicting cooling limit of water source when heat pump operates continuely. Compare with water temperature test data published on existing paper refer to the People's Hospital located in Kaixian county seat, the accuracy and reliability of software model could be authenticated.