Groundwater Source Heat Pump System Research Articles

地下水制御型高効率ヒートポンプ空調システムの研究開発

The developed system included a newly developed groundwater-source heat pump system capable of hybrid operation combining free cooling and heat pumping was installed. In order to prevent scale deposition in the piping and equipment through which groundwater was to flow and clogging of the wells and ground, a water treatment system was installed. Winter test operation was started in November, 2011. Summer test operation was started in June, 2012, and ended in September. Test data obtained in the first year of operation were analyzed. The successful test operation results thus obtained indicate that the developed system is superior in performance to a typical conventional system.

Experimental Study on Pumping and Recharging of Groundwater-Source Heat Pump System in Fuzhou Basin

Groundwater-source heat pump is a new kind of energy conservation and environmental protection air conditioning technology, which is playing a significant role in the development and utilization of the shallow geothermal energy.This paper takes Fuzhou basin as the research object, analyses its regional hydrogeological characteristics, finding Min River terrace and plains are the suitable areas to carry out the tests. On the basis of pumping and recharging experiments, the paper works out the recharging ability, the suitable pumping and recharging wells quantitative proportion of Fuzhou basin main aquifers and the well spacing design parameters between pumping and recharging wells, which provides some scientific evidences for the development of shallow geothermal energy and for the rational application of groundwater-source heat pump technology.

Groundwater Source Heat Pump Technology Use for Heating and Air-Conditioning of a Commercial Building

The groundwater source heat pump (GWHP) system utilizes groundwater as alternative renewable and clean energy source for space heating and cooling, withdraws water from a production well, passes it through a heat exchanger and discharges the water into an injection well. Hebei Province of China is rich of geothermal resources; there are suitable hydrogeological conditions in most areas. Take an office building in Hebei Province for example; a detail loads analysis of the groundwater source heat pump system was conducted. At the same time, an analysis of environmental energy benefits was also conducted. Comparing with the traditional systems for heating and cooling, groundwater source heat pump heating and cooling works well, with significant energy and environmental benefits, should be widely used.

Numerical simulation of the thermal interaction between pumping and injecting well groups

In the thermal energy utilization of a closed loop groundwater system of a groundwater source heat pump (GWHP) and an aquifer thermal energy storage (ATES), thermal breakthrough always occurs. This problem causes a gradual variation in the temperature of the pumping water and impacts the efficiency of the GWHP. In particular, a large scale GWHP system requires many wells; thus, the well location and arrangement become a considerable technological challenge. The aim of this study is to develop a numerical model for groundwater systems to obtain a fair comparison of the energy efficiency between different well locations and arrangement modes. In this study, four typical modes are studied to determine the thermal interaction influences, and the numerical model was verified with test data by using an artificial rock/soil test system. The comparisons show good agreement between the numerical date and the measured data. It is shown that the temperature variation is related to the well arrangement mode, and the row arrangement of well groups may be a better choice. Therefore, a suitable spacing well pattern in the limited area is helpful and can potentially decrease the intensity of the thermal interaction and resist the occurrence of thermal breakthrough.

Energy-saving Diagnosis of Ground Water-source Heat Pump System Based on Artificial Neural Network

Ground water-source heat pump(GWHP)system is currently widely used in China, because of high system energy-efficiency. However, due to the lack of effectively energy-saving diagnostic system, often leads to system operating efficiency be greatly reduced. According to the existing energy efficiency standards used in China, this paper proposes energy-saving state index for GWHP unit and its distribution system, establishes the relationship database between the system monitoring characteristic parameters and the system energy efficiency state, further develops the basic model of standard input about characteristic parameters samples and standard output about system energy-saving diagnosis. Based on the features of artificial neural network’s training & learning, memory & simulation, and non-linear approximation etc., the energy-saving diagnostic function of the GWHP system operation can be obtained, and the factors of system energy-efficient performance degradation can be monitored in real-time and the system energy-saving operation state can be controlled on line.

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.