Effects of Groundwater Heat Pump Systems on the Temperature and Quality of Groundwater in Recharged Aquifer

2014 ◽  
Vol 672-674 ◽  
pp. 379-385
Author(s):  
Bing Hua Li ◽  
Xiao Juan Cao ◽  
Li Cai Liu ◽  
Fan Dong Zheng ◽  
Ni Zhang
Keyword(s):  
Groundwater Quality ◽  
Heat Pump ◽  
Flow Rate ◽  
Relative Reduction ◽  
Injection Wells ◽  
Plain Area ◽  
Pumping Wells ◽  
Groundwater Heat Pump ◽  
Thermal Breakthrough ◽  
Inorganic Components

Groundwater heat pump (GWHP) systems in three different hydrogeological fields, Beijing were selected, and their effects on temperature of groundwater in recharged aquifer were researched for three years. Results showed that the degree of thermal breakthrough was controlled by the distance between pumping wells and injection wells, and the temperature of groundwater with high flow rate can recover to normal faster than those with low flow rate. When distance between pumping wells and injection wells were shorter than 30m, thermal breakthrough may happen and the variation range of groundwater temperature during one heating or cooling period was 8~12°C.However, thermal breakthrough can be negligible and the temperature of groundwater may be steady when the distance between those wells was longer than 50m. Furthermore, GWHP in two different hydrogeological fields were selected to observe their effects on groundwater quality for one year. One GWHP was situated on the northwest piedmont alluvial fan of Beijing and the other was located in the southeast plain area of Beijing. Groundwater was sampled from those fields and thirty-two inorganic components were analyzed. Heavy metals were not detected, and calcium, magnesium, chloride, sulfate, fluoride and other ten inorganic components were studied. Groundwater quality in the northwest of Beijing was relatively steady because that aquifer was in relative oxidation environment. However, groundwater quality in the southeast of Beijing was subject to change because that aquifer was in relative reduction environment. Nitration reaction happened in the plain area, and ammonia, nitrite converted into nitrite nitrogen and nitrate nitrogen, respectively. Simultaneously, pH, concentrations of iron and manganese decreased, and total hardness increased.

Effects of Groundwater Heat Pump Systems on the Temperature and Quality of Groundwater in Recharged Aquifer

2014 ◽  
Vol 670-671 ◽  
pp. 1016-1022
Author(s):  
Bing Hua Li ◽  
Xiao Juan Cao ◽  
Li Cai Liu ◽  
Fan Dong Zheng ◽  
Ni Zhang
Keyword(s):  
Groundwater Quality ◽  
Heat Pump ◽  
Flow Rate ◽  
Relative Reduction ◽  
Injection Wells ◽  
Plain Area ◽  
Pumping Wells ◽  
Groundwater Heat Pump ◽  
Thermal Breakthrough ◽  
Inorganic Components

Groundwater heat pump (GWHP) systems in three different hydrogeological fields, Beijing were selected, and their effects on temperature of groundwater in recharged aquifer were researched for three years. Results showed that the degree of thermal breakthrough was controlled by the distance between pumping wells and injection wells, and the temperature of groundwater with high flow rate can recover to normal faster than those with low flow rate. When distance between pumping wells and injection wells were shorter than 30m, thermal breakthrough may happen and the variation range of groundwater temperature during one heating or cooling period was 8~12°C.However, thermal breakthrough can be negligible and the temperature of groundwater may be steady when the distance between those wells was longer than 50m. Furthermore, GWHP in two different hydrogeological fields were selected to observe their effects on groundwater quality for one year. One GWHP was situated on the northwest piedmont alluvial fan of Beijing and the other was located in the southeast plain area of Beijing. Groundwater was sampled from those fields and thirty-two inorganic components were analyzed. Heavy metals were not detected, and calcium, magnesium, chloride, sulfate, fluoride and other ten inorganic components were studied. Groundwater quality in the northwest of Beijing was relatively steady because that aquifer was in relative oxidation environment. However, groundwater quality in the southeast of Beijing was subject to change because that aquifer was in relative reduction environment. Nitration reaction happened in the plain area, and ammonia, nitrite converted into nitrite nitrogen and nitrate nitrogen, respectively. Simultaneously, pH, concentrations of iron and manganese decreased, and total hardness increased.

Design and Operation Prediction of Groundwater Heat Pump

2012 ◽  
Vol 608-609 ◽  
pp. 983-986
Author(s):  
Xiao Qiong Deng
Keyword(s):  
Heat Pump ◽  
Large Scale ◽  
Water Source ◽  
Temperature Changes ◽  
Average Temperature ◽  
Hydrogeological Parameters ◽  
Groundwater Heat Pump ◽  
Thermal Breakthrough ◽  
Building Load ◽  
Interference Problems

This article based on a large-scale water source heat pump engineering in a city of China, according to the experiment and survey of pumping site as well as hydrogeological parameters combined with the building load requirements, the design scheme of cluster wells pumping and injection was given. A numerical simulation was also done in order to analyze and forecast the temperature changes in aquifer and thermal breakthrough, well group interference problems for the next 3 years. Moreover an experience equation about change of average temperature of water source heat pump wells was got which will provide reference for design and operation of GWHP for others.

scholarly journals Influence of different pumping and recharging schemes on regional groundwater drawdown in groundwater heat pump project: A case in Anhui Fuyang People’s Hospital

2020 ◽  
pp. 316-316
Author(s):  
Jie Yang ◽  
Wei Wang ◽  
Lin Hu ◽  
Yulan Gao ◽  
Yuezan Tao
Keyword(s):  
Water Level ◽  
Heat Pump ◽  
Dynamic Equilibrium ◽  
Production Volume ◽  
Groundwater Drawdown ◽  
Pumping Wells ◽  
Groundwater Heat Pump ◽  
Sustained Operation ◽  
Regional Groundwater ◽  
Recharge Well

In the process of exploiting geothermal energy by groundwater heat pump (GWHP), the dynamic equilibrium of regional groundwater drawdown is the basis for sustained operation of GWHP. In this paper, taking the GWHP project of Fuyang People's Hospital in Anhui, China as an example, a mathematical model is established and numerical simulation is carried out based on the hydrogeological conceptual model by using Modflow software. In addition, considering the pattern of same direction recharge, the intersect recharge and the ratio of 90% and 100% reinjection respectively, the area change of the drawdown funnel caused by the GWHP project and the recovery of the water level after the system stopped operation are analyzed. The results show that the funnel area of the pumping well under the 90% recharge ratio is greater than that of the 100% recharge, while the operation result of recharge well is opposite in the most adverse situation of the system with a production volume of 1440m3/d and continuous operation for 4 months. Furthermore, with the same reinjection ratio, the funnel area of the same direction recharge mode is larger than that of the intersect recharge mode in both pumping wells and recharge wells, and increases with the decrease of drawdown. Moreover, with the increase of recharge amount, while the water level of recharge well rises, there is a certain supplement and balance to the water quantity of the pumping well.

scholarly journals Study on the Long-Term Performance and Efficiency of Single-Well Circulation Coupled Groundwater Heat Pump System Based on Field Test

2021 ◽  
Vol 9 ◽  
Author(s):  
Ke Zhu ◽  
Yifan Zeng ◽  
Qiang Wu ◽  
Shengheng Xu ◽  
Kun Tu ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Heat Pump ◽  
Pump System ◽  
Groundwater Heat Pump ◽  
Heat Pump Unit ◽  
Single Well ◽  
Thermal Breakthrough ◽  
Long Term Performance ◽  
Term Performance

Although buildings are often heated and cooled by single-well circulation coupled groundwater heat pump systems, few studies have evaluated the long-term performance of these systems. Therefore, the present study investigated the performance of these systems by analyzing the efficiency and energy consumption using 4 years of operating data. The results indicate that the coefficient of performance (COP) of the system gradually decreases because of thermal breakthrough or an accumulation of cold. In addition, the sealing clapboards could effectively slow down thermal breakthrough. In addition, compared with the heating period, the COP of the heat pump unit (HPU) and system increases, and its energy consumption decreases in the cooling period. It was also found that partial heat loss occurs when water from the single-well circulation outlet penetrates the main pipeline. Moreover, the heat-exchange efficiency of a single HPU exceeds that of multiple HPUs, and the COP of a HPU decreases during operation with increasing indoor temperature. Accordingly, we improved the performance of system by increasing the underground heat storage. Herein, we focus on optimizing the system design during long-term operation, which includes taking steps such as lengthening the sealing clapboards, using insulated pipes, discharging the remaining water and adding intelligent control devices.

Groundwater quality and pollution evaluation in Xinjiang plain area

2014 ◽  
Author(s):  
Yuanyuan Ji ◽  
Jinlong Zhou ◽  
Yexin Gao ◽  
Qiao Li ◽  
Ruiliang Jia ◽  
...  
Keyword(s):  
Groundwater Quality ◽  
Plain Area ◽  
Pollution Evaluation

Clogging Problems in Groundwater Heat Pump Systems in Sweden

1988 ◽  
Vol 20 (3) ◽  
pp. 133-140 ◽  
Author(s):  
Annika Lindblad-Påsse
Keyword(s):  
Redox Potential ◽  
Heat Pump ◽  
Hydrogen Sulphide ◽  
Sludge Formation ◽  
Iron Bacteria ◽  
Iron Precipitation ◽  
Water Composition ◽  
Groundwater Heat Pump ◽  
And Control ◽  
System Knowledge

A number of groundwater heat pump systems have been investigated to determine the extent of problems caused by the chemistry of the groundwater used. The main purpose was to investigate sites using iron rich groundwater. Fifteen facilities were studied regularly for three years. Ten of these facilities had some kind of problem caused by iron precipitation. Four of the sites were rebuilt because of severe plugging due to iron sludge in wells, pumps and pipes. In all facilities with severe problems, iron bacteria were found. Low redox potential, indicated by hydrogen sulphide in the groundwater, seems to protect from iron bacteria. In some of the systems using groundwater with H2S the problems were corrosion and sludge formation caused by sulphur oxidizing bacteria. Rapid clogging was caused by aeration of the groundwater due to improper design of the system. Knowledge of the water composition, design of the systems to minimize aeration, and control of clogging turned out to be important factors to maintain operation safety.

Investigation into Mechanisms of Microbial Effects on Iron and Manganese Transformations in Artificially Recharged Groundwater

1988 ◽  
Vol 20 (3) ◽  
pp. 47-53 ◽  
Author(s):  
Yan Bao-rui
Keyword(s):  
Groundwater Quality ◽  
Biochemical Reaction ◽  
Reaction Products ◽  
Injection Wells ◽  
Iron Bacteria ◽  
Sulphate Reducing Bacteria ◽  
Prevention And Treatment ◽  
Reducing Bacteria ◽  
Iron And Manganese ◽  
Microbial Effects

After artificial recharging of groundwater some problems occurred, such as changes in groundwater quality, the silting up of recharge (injection) wells, etc. Therefore, the mechanisms of microbial effects on groundwater quality after artificial recharging were studied in Shanghai and the district of Changzhou. These problems were approached on the basis of the amounts of biochemical reaction products generated by the metabolism of iron bacteria, sulphate-reducing bacteria, Thiobacillusthioparus, and Thiobacillusdenitrificans. The experiments showed that in the transformations occurring and the siltation of recharge wells, microorganisms play an important role, due to the various chemical and biochemical activities. A water-rock-microorganisms system is proposed, and some methods for the prevention and treatment of these effects are given.

Determination of optimal well locations and pumping/injection rates for groundwater heat pump system

Geothermics ◽  
2021 ◽  
Vol 92 ◽  
pp. 102050
Author(s):  
Dongkyu Park ◽  
Eunhee Lee ◽  
Dugin Kaown ◽  
Seong-Sun Lee ◽  
Kang-Kun Lee
Keyword(s):  
Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Groundwater Heat Pump ◽  
Injection Rates

Experimental Investigation on Flow Characteristic of Stepped Capillary Tube for Heat Pump Type Air Conditioner with R410A

2014 ◽  
Vol 960-961 ◽  
pp. 643-647
Author(s):  
Yan Sheng Xu
Keyword(s):  
Mass Flow Rate ◽  
Heat Pump ◽  
Mass Flow ◽  
Flow Rate ◽  
Capillary Tube ◽  
Coefficient Of Performance ◽  
Tube Length ◽  
Air Conditioner ◽  
Capillary Tubes ◽  
Tube Assembly

A stepped capillary tube consisting of two serially connected capillary tubes with different diameters is invented to replace the conventional expansion device. The mass flow rate of refrigerant R410A in stepped capillary tubes with different size were tested. The model of stepped capillary tube is proposed, and its numerical algorithm for tube length and mass flow rate is developed. The experimental results show that the performance comparing between stepped capillary tube system and capillary tube assembly system, the cooling capacity is reduced by 0.3%, the energy efficiency ratio (EER) is equal to each other, the heating capacity is increased by 0.3%, the coefficient of performance (COP) is decreased by 0.3%. That is to say, the performance index of the two kinds of throttle mechanism is almost identical. It indicates that the stepped capillary tube can replace the capillary tube assembly in the R410A heat pump type air conditioner absolutely. The model is validated with experimental data, and the results show that the model can be used for sizing and rating stepped capillary tube.

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