Groundwater Source Heat Pump Research Articles

Variation characteristics of aquifer parameters induced by groundwater source heat pump operation under variable flow

The variation characteristics of aquifer parameters, induced by groundwater source heat pump (GWSHP) operation under variable flow, were theoretically analyzed through a case study, in which the characteristics of building air conditioning load were considered. The results, compared with the constant flow operation, indicate that the influence on the variations of porosity, hydraulic conductivity and confined water head is decreased by 48%, 51% and 71%, respectively, under variable flow operation. The security of variable flow operation is superior to that of constant flow. It is also concluded that the climate region and function of the buildings are primary factors which affect the suitability of variable flow operation in GWSHP.

Sensitivity Analysis of Parameters for the Simulation of Thermal Transport in Aquifer: A GSHP System in Chengdu, China

Based on the theory of sensitivity analysis, the local/global sensitivity analysis of parameters for the modeling of thermal transport in aquifer under special groundwater flow and heat source conditions were carried out with the summer running of Groundwater Source Heat Pump (GSHP) system as a study case, by taking the temperature of typical observation points and thermal affected zone (TAZ) of injecting water at the end of summer as the model outputs. The results showed that the sensitivity of each modeling output was various for the different parameter in local analysis. The orders of local sensitivity coefficients of the nine parameters for two modeling outputs were almost coincident. In global sensitivity analysis, the sensitivity of the parameter being investigated was influenced by the different values of other parameters. The two modeling outputs almost had the same variation tendency of global sensitivity with different parameter combinations.

Study on the Energy Saving Control of Groundwater Source Heat Pump Air Conditioning System Based on Integrated Optimization Viewpoint

For an actual project of groundwater source heat pump air conditioning system in Yangli region, by the field investigation on energy usage status of the system operation, analyzes the causes of non-energy-saving operation such as water pumps energy consumption too much, presents an intelligent control strategy of the system energy saving operation for solving the problem, performs the program design of energy saving control based on Programmable Logic Controller (PLC) and variable frequency technique, finally predicts the system energy saving potential.

Analysis of Energy Conservation in a Hybrid Groundwater Source Heat Pump

Analysis of Energy Conservation in a Hybrid Groundwater Source Heat Pump

Exergetic cost analysis of a space heating system

In order to evaluate and improve the design of space heating systems with groundwater source heat pumps (GWHP), common design practices should be examined. In this paper, a GWHP system with common design is studied. The COP of the heat pump is 3.5 at design condition. The system is divided into five subsystems, and exergetic cost analysis is performed on it based on structural theory of thermoeconomics. The results show that the three largest relative exergy destructions and lowest exergy efficiencies occur in power generation and distribution, heat pump, and terminal unit subsystems with relative exergy destructions of 71.2%, 17.1% and 7.02% and exergy efficiencies of 32.8%, 54.8% and 65.6% respectively. The three subsystems also have the largest increases of unit exergetic costs of 2.04 W/W, 2.15 W/W, and 2.73 W/W respectively. Therefore, designers of GWHP space heating systems should pay close attention to heat pump and terminal unit subsystems, especially to the latter one because of its larger increase of unit exergetic cost. The unit exergetic cost of the system final exergetic product is 7.92 W/W. This value can be used to evaluate the system and compare it with others from the viewpoint of energy conservation.

Cost-effective optimal design of groundwater source heat pumps

By analyzing the operating characteristics of the groundwater heat pump, this paper puts forward an integrated optimal mathematical model with an objective function of the annual total costs according to technical and economic optimal principle. A computation program is also developed. On the premise of ensuring that the unit will fulfil the heating and cooling requirements of buildings, this model is used to calculate and optimize some key operating parameters and components according to different temperature and depth of the groundwater. It combines the reliability and economy of heating and cooling and achieves the most optimal match of each part of the system. The present method will lead to a greater improvement in the performance of the heat pump than the traditional method.