Experimental Study on the Heat Transfer in Rock Layers with the Vertical Downhole Heat Exchanger

2010 ◽  
Vol 168-170 ◽  
pp. 2243-2248
Author(s):  
Ying Chun Tang ◽  
Xiao Duo Ou ◽  
Bao Tian Wang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Southwest China ◽  
Thermal Environment ◽  
Ground Source Heat Pump ◽  
In Situ Experiment ◽  
Soil Layers ◽  
Ground Source ◽  
Different Depths

Through the in situ experiment of the ground-source heat pump (abbreviated as “GSHP”) system in Nanning Guangxi, this article has observed the temperature variation rules of the rock layers, by the temperature sensors buried in different depths and different locations from the Heat Exchanger. In addition, this article has also tried to explore the thermal environment of the rocks by analyzing the heat transfer of the soil layers acted under the thermal load in Southwest China regions where the ground water is abundant.

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.

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.

Study on Engineering Construction with Three-Dimensional Heat Transfer Modeling for Double U-Tube Heat Exchangers in Ground-Source Heat Pump Systems

2013 ◽  
Vol 700 ◽  
pp. 231-234
Author(s):  
Lian Yang ◽  
Yong Hong Huang ◽  
Liu Zhang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Pump ◽  
Heat Exchangers ◽  
Three Dimensional ◽  
Ground Source Heat Pump ◽  
Ground Source Heat Pumps ◽  
Engineering Construction ◽  
Single Hole ◽  
Ground Source

There are many ground source heat pumps in engineering construction application. However, Research on heat exchanger models of single-hole buried vertical ground source heat pump mostly focuses on single U-tube ground heat exchangers other than double U-tube ones in China currently. Compared with single U-tubes, double U-tubes have the heat transfer particularity of asymmetry. Therefore, the use of the traditional single tube models would have large error in the simulation of the actual double U-tube heat exchangers. This paper frames a three-dimensional heat transfer model for the vertical single-hole buried double u-tube heat exchanger in a ground source heat pump system. The model considers the performance of U-bube material and uses a dual coordinate system and makes the control elemental volumes superimposed.

Efficiency Analysis of Series Connection Ground Source Heat Pump Water Chiller-Heater Unit

2014 ◽  
Vol 529 ◽  
pp. 625-629
Author(s):  
Chao Yi Tan ◽  
Peng Fei Yang ◽  
Meng Meng Wang ◽  
Hai Hua Hu ◽  
Guo Qiang Zhang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Pump ◽  
Hot Water ◽  
Ground Heat Exchanger ◽  
Ground Source Heat Pump ◽  
Heat Transfer Area ◽  
Pump System ◽  
Series Connection ◽  
Ground Source

In order to improve EER of the ground source heat pump system and reduce heat transfer area of the ground heat exchanger, the authors had developed a series connection ground source heat pump water chiller-heater unit, after theoretical analyses, proved that placing the water chilled in front of the hot water unit could acquire a higher EER comparing to the opposite. In the meantime, this unit had a higher EER than a common water chiller-heater unit or a water chiller-heater unit with condensing heat recovery device. In an air conditioning system of ground source heat pump, employing the above mentioned unit can also reduce heat transfer area of the ground heat exchanger. It suggested that series connection ground source heat pump water chiller-heater unit is a kind of technology with a great development potential.

The Numerical Study on the Environmentally Sustainable System - Ground-Source Heat Pump System

2011 ◽  
Vol 320 ◽  
pp. 530-535 ◽  
Author(s):  
Su Fen Li ◽  
Yan Shang ◽  
Di Chen
Keyword(s):  
Heat Transfer ◽  
Exchange Rate ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Water Temperature ◽  
Heat Pump ◽  
Flow Rate ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Ground Source

In this paper, the coupled thermal conduction and groundwater advection heat transfer model was developed according to the heat-transfer process between the heat exchanger underground and its ambient soil. Soil was considered as saturated porous medium. The paper analyzed that the influence of different inlet flow rate, inlet water temperature, and backfill material on the soil temperature field and heat exchange rate, compared the double U-tube and the single U-tube in numerical simulation. The results show that the enhancing of soil thermal conductivity, inlet water temperature and inlet water flow rate leads to the increase of the heat exchange rate of U tube heat exchanger, and the influence on the double U tube is relativity small. In addition, the heat exchange characteristic of the double U tube is superior to the single U tube. The result has guiding significance to the intermittent operation of the ground source heat pump.

Simulation of Temperature Field of Soil Inside Drilling around a Vertically Buried Single-U-Tube Ground Heat Exchanger

2011 ◽  
Vol 393-395 ◽  
pp. 943-946
Author(s):  
Zhen Yu Du
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Soil Temperature ◽  
Moisture Transfer ◽  
Temperature Fields ◽  
Tube Heat Exchanger ◽  
Heat Transfer Efficiency ◽  
Ground Source ◽  
Practical Engineering ◽  
One Year

In this paper, the mathematical physical model of the heat and moisture transfer, which is about a vertical single-U-tube heat exchanger of a ground source heat pump (GSHP), is used to simulate the soil temperature fields inside drilling around a vertical single-U-tube ground source heat exchanger. The soil temperature fields inside drilling in the GSHP project running for one year are computed numerically. It shows that soil structure, cooling and heating load, cooling and heating period, and convalescence period have been determined by practical engineering conditions, the distance in the plane between drillings have a huge influence on heat transfer effect, only when the distance is designed reasonably, can it be possible to make sure normal heat transfer efficiency.

Ground source heat pump performance in case of high humidity soil and yearly balanced heat transfer

2013 ◽  
Vol 76 ◽  
pp. 956-970 ◽  
Author(s):  
Luigi Schibuola ◽  
Chiara Tambani ◽  
Angelo Zarrella ◽  
Massimiliano Scarpa
Keyword(s):  
Heat Transfer ◽  
Heat Pump ◽  
High Humidity ◽  
Ground Source Heat Pump ◽  
Pump Performance ◽  
Ground Source
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