Operation Optimization Analysis For GWHP Systems In Heating Season

Ground-water heat-pump system uses constant temperature water stored in aquifer asheat source and heat sink. It provides a high efficiency way for heating and coolingwhile consuming a little electrical energy. But in the operation of ground-waterheat-pump systems, the energy saving effect is bad due to the lack of scientificguidance for operating control strategy. The COP of system and heat-pump units areat low levels. The emergence of the phenomenon can be related to the followingreasons. On one hand, thermal transfixion phenomenon happened in the aquifer leadsto a big drop in well water temperature; On the other hand, ground-water heat pumpsystem is the organic whole, and ignoring that would cause the system’s lowperformance while chasing for the best performance for single part of that.To support scientific operation guidance of ground-water heat-pump system inheating period, in this paper the running strategy of ground water heat pumps wasstudied. Firstly, water and heat movement coupling model was fitted out, andcalculated on the heat transfer simulation software FlowHeat. A ground watercalculation model under the slow-heat-transfixion was made according to thesimulated result. And the effect of transient-heat-transfixion was analyzed, and acorrection factor was added up. Finally ground water calculating model on thecondition of changing heat removal had been established.Secondly, we calculated heating parameters at different outdoor temperatures onthe basis of building heat load and terminal equipment characteristic equation. Then,the model of energy consumption for heat pump and water pump were established.The method for optimization operating parameters of underground water so urce heatpump system with the goal of minimizing the total energy consumption wereestablished on the basis of above model.At last, a field test on groundwater heat pump system in Beijing was carried out andthe data was analyzed. The calculation model of its groundwater temperature wasobtained based on actual tested well temperature. In addition, the lithologic parameterof its aquifer and arrangement mode of well group was considered as well. Its heatingparameters at outdoor temperature were modified on the basis of measured data. Theenergy consumption calculation models of its heat pump host and water pump were built combined with operation parameter and equipment samples. On this basis, theoptimized running control equation of its system was estab lished. At last, the optimaloperation strategy of this system under different outdoor temperatures was obtainedbased on the control equation before.The new system operation optimization idea for taking the every part of theground-water heat-pump into account that put forward in this article has an importantguiding significance to the actual operation of underground water source heat pump.