The experimental study on thermal conductivity of backfill material of ground source heat pump based on iron tailings

2018 ◽  
Vol 174 ◽  
pp. 1-12 ◽  
Author(s):  
Rong Wan ◽  
Dequan Kong ◽  
Jiayuan Kang ◽  
Tianyu Yin ◽  
Jiangfeng Ning ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Experimental Study ◽  
Heat Pump ◽  
Ground Source Heat Pump ◽  
Backfill Material ◽  
Ground Source

Experimental Study on a Ground Source Heat Pump System in Cold Area

2011 ◽  
Vol 71-78 ◽  
pp. 2566-2571 ◽  
Author(s):  
Yi Liu ◽  
Ya Xuan Wang ◽  
Ya Ning Zhang
Keyword(s):  
Experimental Study ◽  
Heat Pump ◽  
Operation Time ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Ground Source ◽  
Cold Area

Experiment of a ground source heat pump system in cold area is studied in this paper. The results indicate that when the operation time increases to 100 hours, COPHP (COP of the heat pump) and COPSYS (COP of the system) decrease from 3.54 and 2.63 to 2.53 and 1.92, respectively. The average values of COPHP and COPSYS are 3.1 and 2.3, respectively. COPHP and COPSYS with 2 compressors at work are 11% and 12.2% higher than COPHP and COPSYS with 4 compressors at work, respectively. The average COPSYS with inverters is 6.42% higher than the COPSYS without inverters.

scholarly journals Ground-Source Heat Pump Systems: The Effects of Variable Trench Separations and Pipe Configurations in Horizontal Ground Heat Exchangers

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3919
Author(s):  
Yu Zhou ◽  
Asal Bidarmaghz ◽  
Nikolas Makasis ◽  
Guillermo Narsilio
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Heat Pump ◽  
Heat Exchangers ◽  
Element Model ◽  
Fluid Temperature ◽  
Ground Source Heat Pump ◽  
Carrier Fluid ◽  
Ground Heat Exchangers ◽  
Ground Source

Ground-source heat pump systems are renewable and highly efficient HVAC systems that utilise the ground to exchange heat via ground heat exchangers (GHEs). This study developed a detailed 3D finite element model for horizontal GHEs by using COMSOL Multiphysics and validated it against a fully instrumented system under the loading conditions of rural industries in NSW, Australia. First, the yearly performance evaluation of the horizontal straight GHEs showed an adequate initial design under the unique loads. This study then evaluated the effects of variable trench separations, GHE configurations, and effective thermal conductivity. Different trench separations that varied between 1.2 and 3.5 m were selected and analysed while considering three different horizontal loop configurations, i.e., the horizontal straight, slinky, and dense slinky loop configurations. These configurations had the same length of pipe in one trench, and the first two had the same trench length as well. The results revealed that when the trench separation became smaller, there was a minor increasing trend (0.5 °C) in the carrier fluid temperature. As for the configuration, the dense slinky loop showed an average that was 1.5 °C lower than those of the horizontal straight and slinky loop (which were about the same). This indicates that, when land is limited, compromises on the trench separation should be made first in lieu of changes in the loop configuration. Lastly, the results showed that although the effective thermal conductivity had an impact on the carrier fluid temperature, this impact was much lower compared to that for the GHE configurations and trench separations.

Experimental Study of A Solar Assisted Ground Source Heat Pump for Heating

2014 ◽  
Vol 2 (2) ◽  
pp. 146-149 ◽  
Author(s):  
Zhongchao Zhao ◽  
Weixian Feng ◽  
Haojun Mi ◽  
Hua Cheng ◽  
Long Yun ◽  
...  
Keyword(s):  
Experimental Study ◽  
Heat Pump ◽  
Ground Source Heat Pump ◽  
Ground Source

A Study on the Calculation Model of Rock Soil Thermal Conductivity in the Design of the Ground Source Heat Pump System

2014 ◽  
Vol 889-890 ◽  
pp. 1347-1352
Author(s):  
Hong Wen Jin ◽  
Qing Shen Fang
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Pump ◽  
Soil Layer ◽  
Heat Extraction ◽  
Ground Source Heat Pump ◽  
Soil Thermal Conductivity ◽  
Pump System ◽  
Heat Pump System ◽  
Ground Source

The rock soil thermal conductivity is the most important design parameter for the ground source heat pump system. Based on the equation applied for the heat transfer between the geothermal heat exchanger and its surrounding rock soil, a quasi-three dimensional heat conduction model showing the heat transfer inside the borehole of the U-tube was established to determine the thermal conductivity of the deep-layer rock soil. The results obtained show that the average thermal conductivity got through calculation and actual determination in a tube-embedding region of the ground source heat pump engineering were 1.895 and 1.955W/(m·°C), respectively. The soil layer, which has a great thermal conductivity and a strong integrated heat transfer capability, is suitable for the use of the ground source heat pump system with the tubes embedded underground. The soil layer, with a body temperature of 19 °C and a higher initial temperature, is suitable for the heat extraction from underground in winter. The deviation between the calculation and the determination of the average thermal conductivity in the abovementioned region was 0.06, which could meet the required precision, indicating that the results from the calculation could be used for design.

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