Advances in Ground Source Heat Pump Systems Applied in Most Areas of China: A Review

2014 ◽  
Vol 716-717 ◽  
pp. 805-808 ◽  
Author(s):  
Xin Wang ◽  
Hong Liu ◽  
Di Di Xue
Keyword(s):  
Heat Pump ◽  
Heat Pumps ◽  
Ground Heat Exchanger ◽  
Ground Source Heat Pump ◽  
Heat Accumulation ◽  
Ground Source ◽  
Heating Load ◽  
The Difference ◽  
Thermal Imbalance ◽  
System Operating

Because of the advantage on energy saving and environmental sustainable development, the ground source heat pump (GSHP) system has received the widespread attention and application in recent years.However,the difference between cooling load in summer and heating load in winter is obvious in most areas of our country,so it can cause the heat accumulation around ground heat exchanger,which will result in degradation of system performance and increment of system operating costs.To solve the problem of thermal imbalance,it is necessary to research the soil temperature field around the buried pipes in the process of system operation.This paper begins with a review of the studies about the ground source heat pump systems.This is followed by a review of various methods of enhancing the performance of heat pumps based on the thermal imbalance.And then,this paper shows some studies about ground source heat pump systems based on the groundwater seepage.

Investigating the Effect of Soil Type and Moisture on the Performance of a Ground Source Heat Pump System Used for a Greenhouse in Iran

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Pedram Bigdelou ◽  
Fathollah Pourfayaz ◽  
Younes Noorollahi
Keyword(s):  
Heat Transfer ◽  
Heat Pump ◽  
Electricity Consumption ◽  
Working Hours ◽  
Heat Pumps ◽  
Silty Clay ◽  
Ground Heat Exchanger ◽  
Ground Source Heat Pump ◽  
Ground Source ◽  
Silty Loam

Abstract We investigate the effect of soil type and moisture on the operation of a ground source heat pump (GSHP) system in supplying the energy needs of a greenhouse in Karaj, Alborz province, Iran, in terms of the required length of ground heat exchanger, the working hours, the electricity consumption, as well as the coefficient of performance (COP) of heat pumps. In order to predict the capacity of heat pumps, we use the numerical heat transfer model of Noorollahi et al. (2016, “Numerical Modeling and Economic Analysis of a Ground Source Heat Pump for Supplying Energy for a Greenhouse in Alborz Province, Iran,” J. Cleaner Prod., 131, pp. 145–154) in which the governing equations of heat transfer in the ground heat exchanger are numerically solved through a novel finite difference method. Thermal properties of various soil types, namely sandy soil, sand, silty loam, and silty clay, with three different levels of moisture content referred to as dry, damp, and saturated, are considered as the main inputs for the computer code. The simulations indicate that when moisture is increased from dampness to saturation, the annual working hours of heat pumps decrease by 1.1%, 5.1%, 6.1%, and 4.6%, and their annual electricity consumption is reduced by 2.2%, 10.6%, 12.6%, and 9.7% for sandy soil, sand, silty loam, and silty clay, respectively. Moreover, the average COP of heat pumps increase by 0.9%, 4.0%, 5.2%, and 3.7% in heating mode and 2.4%, 13.0%, 16.5%, and 11.7% in cooling mode for the mentioned soils, respectively.

Performance Evaluation of a Vertical U-Tube Ground Heat Exchanger Using a Numerical Simulation Approach

2013 ◽  
Vol 724-725 ◽  
pp. 909-915
Author(s):  
Ping Fang Hu ◽  
Zhong Yi Yu ◽  
Fei Lei ◽  
Na Zhu ◽  
Qi Ming Sun ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Performance Evaluation ◽  
Heat Exchanger ◽  
Heat Pump ◽  
Heat Transfer Process ◽  
Working Fluid ◽  
Outlet Temperature ◽  
Ground Heat Exchanger ◽  
Ground Source Heat Pump ◽  
Ground Source

A vertical U-tube ground heat exchanger can be utilized to exchange heat with the soil in ground source heat pump systems. The outlet temperature of the working fluid through the U-tube not only accounts for heat transfer capacity of a ground heat exchanger, but also greatly affects the operational efficiency of heat pump units, which is an important characteristic parameter of heat transfer process. It is quantified by defining a thermal effectiveness coefficient. The performance evaluation is performed with a three dimensional numerical model using a finite volume technique. A dynamic simulation was conducted to analyze the thermal effectiveness as a function of soil thermal properties, backfill material properties, separation distance between the two tube legs, borehole depth and flow velocity of the working fluid. The influence of important characteristic parameters on the heat transfer performance of vertical U-tube ground heat exchangers is investigated, which may provide the references for the design of ground source heat pump systems in practice.

scholarly journals Ground-Source Heat Pumps with Horizontal Heat Exchangers for Space Cooling in the Hot Tropical Climate of Thailand

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1274 ◽  
Author(s):  
Arif Widiatmojo ◽  
Sasimook Chokchai ◽  
Isao Takashima ◽  
Yohei Uchida ◽  
Kasumi Yasukawa ◽  
...  
Keyword(s):  
Economic Growth ◽  
Heat Pump ◽  
Heat Exchangers ◽  
Life Cycle Cost ◽  
Heat Pumps ◽  
Ground Source Heat Pump ◽  
Ground Source Heat Pumps ◽  
Air Source Heat Pump ◽  
Ground Source ◽  
Space Cooling

The cooling of spaces in tropical regions, such as Southeast Asia, consumes a lot of energy. Additionally, rapid population and economic growth are resulting in an increasing demand for space cooling. The ground-source heat pump has been proven a reliable, cost-effective, safe, and environmentally-friendly alternative for cooling and heating spaces in various countries. In tropical countries, the presumption that the ground-source heat pump may not provide better thermal performance than the normal air-source heat pump arises because the difference between ground and atmospheric temperatures is essentially low. This paper reports the potential use of a ground-source heat pump with horizontal heat exchangers in a tropical country—Thailand. Daily operational data of two ground-source heat pumps and an air-source heat pump during a two-month operation are analyzed and compared. Life cycle cost analysis and CO2 emission estimation are adopted to evaluate the economic value of ground-source heat pump investment and potential CO2 reduction through the use of ground-source heat pumps, in comparison with the case for air-source heat pumps. It was found that the ground-source heat pumps consume 17.1% and 18.4% less electricity than the air-source heat pump during this period. Local production of heat pumps and heat exchangers, as well as rapid regional economic growth, can be positive factors for future ground-source heat pump application, not only in Thailand but also southeast Asian countries.

scholarly journals Sensitivity analysis using simulations for a ground source heat pump – implementation on a solar passive house

2019 ◽  
Vol 111 ◽  
pp. 01070
Author(s):  
Gheorghe Ilisei ◽  
Tiberiu Catalina ◽  
Robert Gavriliuc
Keyword(s):  
Sensitivity Analysis ◽  
Heat Pump ◽  
Fossil Fuels ◽  
Electricity Consumption ◽  
Heat Pumps ◽  
Ground Source Heat Pump ◽  
Passive House ◽  
Modeling Tools ◽  
Ground Source Heat Pumps ◽  
Ground Source

Having in sight the need for a strong reduction in CO2 emissions and the fluctuation of the price of fossil fuels, the ground source resources alongside with the ground source heat pumps are becoming more and more widespread for meeting the heating/cooling demand of several types of buildings. This article targets to develop the thermal modelling of borehole heat storage systems. Trying to emphasize some certain advantages of a GSHP (ground source heat pump) with vertical boreholes, a case study analysing a residential solar passive house is presented. The numerical results are produced using different modelling software like DesignBuilder, EED (Earth Energy Designer) and a sizing method for the length of the boreholes (ASHRAE method). The idea of sizing the length of boreholes (main design parameter and good index in estimating the system’s cost) using two different methods shows the reliability of this modelling tool. The study shows that borehole’s length of a GSHP system can trigger a difference in electricity consumption up to 22%. Moreover, this sensitivity analysis aims to prove that the design of the whole system can be done beforehand just using modeling tools, without performing tests in-situ.

scholarly journals Selection and techno-economic analysis of hybrid ground source heat pumps used in karst regions

2020 ◽  
Vol 103 (2) ◽  
pp. 003685042092168
Author(s):  
Weisong Zhou ◽  
Peng Pei ◽  
Ruiyong Mao ◽  
Haibin Qian ◽  
Yanbing Hu ◽  
...  
Keyword(s):  
Economic Analysis ◽  
Heat Pump ◽  
Groundwater Resources ◽  
Heat Pumps ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Ground Source Heat Pumps ◽  
Ground Source ◽  
Heat Buildup

In order to take advantage of different forms of heat pumps and to mitigate thermal imbalance underground caused by long-term operation of ground source heat pumps, hybrid ground source heat pump systems have received an increasing attention. In this research, based on the fact that abundant groundwater resources are commonly available in karst regions, a new strategy is introduced for selecting and determining hybrid ground source heat pump capacity. Five scenarios of hybrid ground source heat pump system coupling groundwater source heat pumps with other supplementary heat pumps are proposed in this article to provide appropriate options to eliminate heat buildup under different hydrogeologic conditions. Methodologies for sizing and selection are established. Then, a case study of techno-economic analysis was performed for a project in the karst region in South China. The results showed that these scenarios can effectively mitigate heat buildup, and under the hydrogeologic condition in the case study. Compared to the solo ground-coupled heat pump solution, the optimal solution (Solution 4 in this study) can reduce the annual costs by 16.10% and reduce the capital investment by 60%. Methodologies developed in this study are beneficial for selecting appropriate approaches to mitigate heat buildup and enhance competitiveness of ground source heat pumps.

Simulation on Ground Temperature Change of GSHP System in Severe Cold Regions

2014 ◽  
Vol 945-949 ◽  
pp. 2820-2824 ◽  
Author(s):  
Li Bai ◽  
Peng Xuan Wang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Temperature Change ◽  
Heat Pump ◽  
Ground Heat Exchanger ◽  
Ground Source Heat Pump ◽  
Cold Regions ◽  
Ground Source ◽  
Ground Coupled Heat Pump ◽  
Operation And Management

For the case of ground-source heat pump in severe cold regions in winter, the heat transfer situation of the ground and ground heat exchanger was dynamically simulated according to the statistics of a project in Changchun to analysis the change of the ground heat, which provided references for the initial design and operation and management of the ground-coupled heat pump in severe cold regions.

Annual pattern of the coefficient of performance considering several heat pump types and its environmental consequences

2014 ◽  
Vol 5 (2) ◽  
pp. 173-179
Author(s):  
T. Buday ◽  
Gy. Szabó ◽  
I. Fazekas ◽  
M. Paládi ◽  
Sz. Szabó ◽  
...  
Keyword(s):  
Heat Pump ◽  
Water Source ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Conventional Heating ◽  
Temperature Pattern ◽  
Ground Source Heat Pump ◽  
Environmental Consequences ◽  
Ground Source ◽  
Heating Mode

Heating with the use of ambient energy by heat pumps is a very effective way to reduce CO2 emission. However, efficiency, economic and environmental advantages depend on the type of the heat pump and the temperature of the source, the latter usually changes during the heating season. The aim of the paper is to give the annual pattern of the COP and emission as a function of the typical source temperature pattern, moreover yearly summarized energetic and emission values are also added in the case of air source, water source and ground source heat pump systems, compared to some conventional heating mode.

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