scholarly journals Numerical simulation of ground source heat pump systems considering unsaturated soil properties and groundwater flow

2018 ◽  
Vol 139 ◽  
pp. 307-316 ◽  
Author(s):  
Chaofeng Li ◽  
Peter John Cleall ◽  
Jinfeng Mao ◽  
José Javier Muñoz-Criollo
Keyword(s):  
Numerical Simulation ◽  
Groundwater Flow ◽  
Soil Properties ◽  
Heat Pump ◽  
Unsaturated Soil ◽  
Ground Source Heat Pump ◽  
Ground Source

Numerical Simulations of a Ground Source Heat Pump System With Pile Heat Exchangers

2014 ◽  
Vol 7 (1) ◽  
Author(s):  
Masahito Oguma ◽  
Takeshi Matsumoto ◽  
Takao Kakizaki
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Heat Pump ◽  
Heat Exchangers ◽  
Heat Supply ◽  
Ground Surface ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Ground Source

Feasibility of a ground source heat pump (GSHP) system with pile heat exchangers for use in houses is evaluated through a numerical simulation. This GSHP system differs from ordinary borehole-type GSHP systems because short foundation piles installed at close intervals are used as heat exchangers. It is shown that the annual heat supply provided by this GSHP system is able to satisfy the demand of a house due to the air-source exchange at ground surface.

Heat Transfer Analysis of Groundwater Flow for Ground Heat Exchangers in the Multi-Borehole Field of Ground Source Heat Pump under the Intermittent Operation

2014 ◽  
Vol 548-549 ◽  
pp. 595-600
Author(s):  
Can Can Zhang ◽  
Yue Jin Yu
Keyword(s):  
Groundwater Flow ◽  
Heat Pump ◽  
Heat Exchangers ◽  
Heat Transfer Analysis ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Ground Heat Exchangers ◽  
Ground Source ◽  
Thermal Interference

In order to analyze the influence of groundwater flow on ground heat exchangers with different arrangements, with a project in Nanjing the access temperature field in the multi-borehole field was simulated after the ground source heat pump system had been performed for a year. Simulation results show that the access temperature is higher in the ground surrounding the borehole than the center of the corresponding borehole, thus forming a thermal barrier surrounding the borehole. Groundwater flow helps relieve temperature imbalance owing to the imbalance of heating and cooling load. The performance of the ground heat exchangers is better in staggered arrangement than in aligned arrangement. In the borehole field, the boreholes upstream have thermal interference on those downstream. And the extent of thermal interference depends on the direction of the groundwater flow when the locations of the boreholes are fixed in the borehole field.

3D Numerical Simulation of Heat Transfer for the Vertical U Type Berried Pipe of the Ground Source Heat Pump

2013 ◽  
Vol 827 ◽  
pp. 203-208
Author(s):  
Yang Zhang ◽  
Yong Feng Qi
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Finite Element ◽  
Heat Pump ◽  
Element Model ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Ground Source ◽  
Heat Transfer Theory

Based on transient heat transfer theory and finite element method, a 3D finite element model was created to simulate the heat transfer of the vertical U type berried pipe of the ground source heat pump system. At the same time, the pipe algorithm applied successfully in the numerical simulation of concrete temperature field was introduced. The corresponding program was written. Taking the true experiment conditions as the input data and boundary condition of the computation model, the 3D dynamic simulation of the heat transfer between the berried pipe and sandy soil was carried out. The calculated temperatures of the output water of the pipe and the measure points in soil at different times met the experiment results very well, which verified the effectiveness and the reliability of the algorithm and the model. Beneficial exploration is made for providing more detailed and accurate data for the designer.

The Effects of Groundwater Flow on Vertical-Borehole Ground Source Heat Pump Systems

2014 ◽  
Author(s):  
Ayako Funabiki ◽  
Masahito Oguma ◽  
Taisei Yabuki ◽  
Takao Kakizaki
Keyword(s):  
Thermal Conductivity ◽  
Heat Flux ◽  
Groundwater Flow ◽  
Flow Velocity ◽  
Heat Pump ◽  
High Thermal Conductivity ◽  
Ground Source Heat Pump ◽  
Ground Heat Exchangers ◽  
Ground Source ◽  
Gravel Size

Heat advection by groundwater flow is known to improve the performance of ground heat exchangers (GHEs), but the effect of groundwater advection on performance is not yet fully understood. This study examined how parameters related to groundwater flow, such as aquifer thickness, porosity, lithology, and groundwater flow velocity, affect the performance of a borehole GHE. Under the thin-aquifer condition (10 m, or 10% of the entire GHE length in this study), groundwater flow velocity had the greatest effect on heat flux. With a groundwater flow velocity of at least 10−4 m/s through a low-porosity aquifer filled with gravel with high thermal conductivity, the heat flux of a GHE was as much as 60% higher than that of a non-aquifer GHE. If the aquifer is as thick as 50 m (50% of the entire GHE length), the high thermal conductivity of gravel doubled the heat flux of the GHE with a groundwater flow velocity of at least 10−5 m/s. Thus, not only groundwater flow velocity, but also aquifer thickness and thermal conductivity were important factors. However, groundwater seldom flows at such high velocities, and porosity, gravel size, and aquifer thickness vary regionally. Thus, in the design of ground source heat pump systems, it is not appropriate to assume a large groundwater effect.

The Numerical Simulation of Ground Source Heat Pump

2012 ◽  
Vol 608-609 ◽  
pp. 979-982
Author(s):  
Jian Zhang ◽  
Ling Wang
Keyword(s):  
Numerical Simulation ◽  
Heat Exchanger ◽  
Heat Pump ◽  
Temperature Difference ◽  
Ground Heat Exchanger ◽  
Three Dimension ◽  
Ground Source Heat Pump ◽  
Ground Source ◽  
Set Up

Set up the three dimension model of ground heat exchanger, consider the temperature variety between inlet and outlet, at the same make the zone into two parts. Use the fluent to slove it . The results prove that because of the temperature difference between inlet and outlet, the temperature approach inlet varies serious than that approach outlet. With the depth increasing, the temperature difference would be little, but the center temperature is high.

Enhancement of Soil Thermo-Physical Properties Using Microencapsulated Phase Change Materials for Ground Source Heat Pump Applications

2011 ◽  
Vol 110-116 ◽  
pp. 1191-1198 ◽  
Author(s):  
Pejman Keikhaei Dehdezi ◽  
Matthew R. Hall ◽  
Andrew R. Dawson
Keyword(s):  
Numerical Simulation ◽  
Physical Properties ◽  
Phase Change ◽  
Heat Pump ◽  
Phase Change Materials ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Ground Source ◽  
Thermo Physical Properties ◽  
Modified Soil

Soil can be modified with Phase Change materials (PCM) in order to enhance its thermo-physical properties and energy storage for ground source heat pump applications. This paper studies thermo-physical properties of soil modified with different amount of microencapsulated PCM. It is shown that increasing PCM amount in soil lead to lower thermal conductivity and increase of volumetric heat capacity of PCM-modified soil across the PCM melting temperature range. In addition, numerical simulation is performed to study the potential application of PCM-modified soil for reduction of temperature variations in ground. The result of numerical simulation revealed that temperature variation under PCM-modified soil can be reduced by up to 3°C compared to conventional soil. This could improve the Coefficient of performance of a heat pump system by more than 17%.

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