Underground Water Source Heat Pump Research Articles

Experimental Study on Automatic Switching of Solar Coupled Groundwater Source Heat Pump System

There have been few practical applications of solar coupled groundwater source heat pump (GWHP) systems in large public buildings, and data on this technology are scarce. A solar coupled GWHP system was investigated in this study. The system uses an underground water source heat pump system for heating in winter, cooling in summer, and providing part of the domestic hot water, and it also uses a solar energy system to prepare domestic hot water. These two types of energy are complementary. The system was tested throughout the cooling season. This experiment ran from May 10, 2021, to September 10, 2021. The results show that the system can guarantee the indoor design temperature and the supply of domestic hot water. The solar water heating system operated for 1233 min in the summer; hot water (2334 m3) was prepared. During the summer, the average energy efficiency ratio of the GWHP unit was approximately 4.88. The energy efficiency ratio of the entire system was approximately 3.34. Such projects can play a key role in demonstrating this type of system.

Energy and economic analysis of an under-ground water source heat pump system for a historical valuable building

The heating, ventilation and air conditioning plant of a historical valuable building in the centre of Vicenza (Italy) was retrofitted during 2007-2012 period. An underground water source electrical compression heat pump was installed with a monitoring and data logging system. In this paper the analysis of the performance data of the last three cooling seasons and the last two heating seasons (2014-2016) is developed. The analysis reveals that some critical aspects determined poor energy performance of the plant during the first operation period. Such issues and the technical solutions suggested by the Authors are presented in this work.

Study on Optimization of Underground Water Source Heat Pump

Based on the study of groundwater source heat pump air conditioning system, the thermodynamic characteristics of the water source heat pump system are analyzed in detail. This paper analyzes the energy saving optimization of a new type of underground water source heat pump system, making the groundwater source heat pump system more efficient and energy saving. Based on the theory of thermal economics and quantitative analysis, five independent variables are selected as the variable parameters of the thermal economic analysis after designing the objective optimization function. The exergy efficiency under several variable values are discussed, and then a comparative analysis is carried out. Finally, the parameters of the traditional water source heat pump and the optimized new water source heat pump are compared through the experiment. We found that the compressor power consumption of traditional underground water source heat pump system is greater than that of the new underground water source heat pump system. The exergy efficiency of the new underground water source heat pump system is high and the annual total cost is low. So the water source heat pump system has higher exergy efficiency, better economic and better exergy efficiency after optimization design.

Measurement and Analysis of A Heating System Based on Underground Water Source Heat Pump in Zhangye City

The heating system based on the underground water source heat pump is energy saving and environment friendly, but its operation effect in the cold area of Northwest China is rarely reported. The heating area of the underground water source heat pump system located in No.2 Middle School, Zhangye city, is 72755 m2. The system mainly consists of two sets of heat pump systems in parallel and each system includes a small-capacity heat pump in series with a high-capacity heat pump. Some parameters are tested from Jan. 25 to Mar. 31, 2016. Based on the test data, this paper calculates and analyses the energy utilization of the system. The heating effect of the system is good and the coefficient COP of the heating system, the high-capacity heat pump and the small-capacity heat pump are 3.67, 4.3 and 6.24 respectively.

基于层次分析法的浅层地温能适宜性评价分析—以兰州市中心城区为例

依据实际勘查资料和测试数据，采用层次分析法所建立的数学评价模型，对兰州市中心城区面积384.7km2的区域进行了浅层地温能适宜性评价分析。浅层地温能适宜性评价体系地下水源热泵共建立了3个属性准则和10个要素指标，土源热泵共建立了3个属性准则和8个要素指标，分别构建了各层次的判断矩阵，并全部高精度通过一致性验证。评价结果，地下水源热泵适宜、较适宜区占调查区总面积的38.99%，主要分布于断陷盆地及黄河黄河I~III级阶地区及和平、定远盆地大部等含水层富水性较好、单井涌水量1000~5000 m3/d、矿化度小于1.0 g/L的地带；土源热泵适宜、较适宜区占调查区总面积的68.57%，主要分布于黄河两岸III~IV级高阶地区与黄土丘陵过度地带及和平、定远盆地等包气带细颗粒地层厚度大于20~40 m、地下水位埋深大于25 m的地带；调查区其余地带不适宜浅层地温能的建设。评价结果对兰州市中心城区浅层地温能的开发利用具有重要的指导作用。 Based on the actual survey data and the test data, the shallow geothermal energy of Lanzhou city center (the area of 384.7 km2) is evaluated and classified by the way of analytic hierarchy pro- cess (AHP). In the evaluation system, 3 criteria and 10 indicators are established for underground water source heat pump, 3 criteria and 8 factors for soil source heat pump, all levels of judgment matrix are constructed and precision through consistency checking. The results show that the area of underground water source heat pump suitable and suitable for the survey area with a total area of 38.99%, which mainly distributed in the fault basin, Yellow River level I - III and the large parts basin of Heping and Dingyuan that the water rich water content is better, the single well water inflow 1000 - 5000 m3/d, the mineralization degree is less than 1.0 g/L. The soil source heat pump suitable and suitable areas for 68.57% of the total area of the survey area, which mainly distributed on both sides of the Yellow River level III - IV higher-order region and the Loess Hilly transition zone, Heping and Dingyuan basin, which aeration with fine grain layer thickness is greater than 20 - 40 m, groundwater depth more than 25 m. The rest of the survey area is not suitable for the construction of shallow geothermal energy. The research results have an important guiding role for the development and utilization of shallow geothermal energy in the central urban area of Lanzhou city.

Comparison of coefficient of performance (<i>COP</i>) between an underground water source heat pump system and an air source heat pump system for greenhouse heating in cold and snowy areas in Japan

Comparison of coefficient of performance (<i>COP</i>) between an underground water source heat pump system and an air source heat pump system for greenhouse heating in cold and snowy areas in Japan

Optimization model analysis of centralized groundwater source heat pump system in heating season

The ground-water heat-pump system (GWHP) provides a high efficient way for heating and cooling while consuming a little electrical energy. Due to the lack of scientific guidance for operating control strategy, the coefficient of performance (COP) of the system and units are still very low. In this paper, the running strategy of GWHP was studied. First, the groundwater thermal transfer calculation under slow heat transfixion and transient heat transfixion was established by calculating the heat transfer simulation software Flow Heat and using correction factor. Next, heating parameters were calculated based on the building heat load and the terminal equipment characteristic equation. Then, the energy consumption calculation model for units and pumps were established, based on which the optimization method and constraints were established. Finally, a field test on a GWHP system in Beijing was conducted and the model was applied. The new system operation optimization idea for taking every part of the GWHP into account that put forward in this paper has an important guiding significance to the actual operation of underground water source heat pump.

Temperature field analysis of underground water source heat pump based on surfacelet finite element method

In order to avoid the occurrence of heat transfixion, the temperature field distribution of underground water source heat pump should be found out, and therefore, the surface finite element method is used to analyze temperature of underground water source heat pump. Firstly, the related researches are summarized. Secondly, the basic feature of surfacelet transform is studied. Thirdly, the surfacelet finite element formulation is proposed through combing the surfacelet transform and traditional finite element method for analyzing the temperature field of underground water source heat pump. Then, temperature field model of underground water source heat pump is established. Finally, the temperature field analysis of underground water source heat pump is analyzed based on traditional finite element method, B-spline wavelet finite element method and surfacelet finite element method, respectively, and results show that the surfacelet finite element method has highest computing accuracy and efficiency; in addition, the measurements that avoid the heat transfixion of system are put forward.

The Study on Thermal Interaction of the Underground Water Source Heat Pump’s Different Pumping/Injecting Well Groups’ Arranged Modes

The coupled model of groundwater flow and temperature is established, the thermal interaction of different pumping/injecting well groups arranged modes is simulated and analyzed, and the changing trend of groundwater temperature is predicted, which is to propose reasonable arranged wells programs. The thermal interaction of groundwater is compared and analyzed according to different arranged wells scheme, the pumping/injecting wells distance affect the thermal interaction significantly, the similar wells distance didnt affect significantly. The more number of pumping/injecting wells the thermal interaction is weaker, in order to delay the time of heat through, solve the problem of poor water recharge, we should increase appropriately the injecting wells number under keeping the pumping wells number constant.

The Numerical Simulation of the Aquifer Thermal Energy Storage Technology

The aquifer thermal energy storage (ATES) system can make use of the heat of summer and the cold of winter, despite in different seasons, which can help to reduce the usage of the fossil fuel effectively, as a result, the atmospheric pollution can be reduced. This article firstly summarized the fundamental principles and the classifications of the ATES, and it also deduced and established the ATES mathematical model, and then numerical difference arithmetic was used to program so as to gain the simulation results. On the basis of the above, the author looks forward to the prospective of the aquifer thermal energy, and also provides the references to the applications of the ATES and the studies of the underground water source heat pump.