The thermal properties of the ground are mainly determine by the minerals , water saturation and porosity. The thermal conductivity is depend upon porosity when the porosity increase thermal conductivity is gradually decrease due to that water and air are less conductive as compare to minerals, and on the other hand heat capacity increase with higher water content. During the installation of heat exchanger soil loss it structure due to drilling then the thermal conductivity is determined by mineral contain. The porosity of soil varies from place to place some kind of soil having less porosity but on the other hand some having high porosity like peat which consume water approximate 100%.
To sum up, the important factor of the variation of the thermal property during the storage cycle in the degree of water saturation. Change in water saturation occur in the unsaturated zone specially near to the ground water level. In permeable materials their may also be significant fluctuation in the ground water level.
Surface roughness
The most of the thermal resistance is happened during in turbulent flow …show more content…
In this analysis using of U shape BHE in different distance size of inlet and outlet pipe due to this the thermal resistance and relativity error are found. In this project I also used ansys program for analysis of inlet and outlet temperature of water in ground heat exchanger. The thermal properties of heat exchanger is changed due to it roughness of the pipe and it shows some error and it should be neglected only by cleaning of pipe in proper time. The flow rate of the exchanger is totally depend on the flow of pipe if the pipe having turbulent flow then the heat transfer is very low on the other hand if the pipe having laminar flow the heat transfer rate is higher. The thermal resistance is inversely proportional to the flow rate of heat