Heat recovery from ground below the solar pond

Abstract

The method of heat recovery from the ground below solar ponds is investigated in the present brief note. Solar ponds lose considerable amount of heat from its bottom to the ground due to temperature gradient between them. This waste heat from ground, which is at different temperature at different depths decreasing downwards from the bottom of the solar pond, can be extracted to enhance the thermal performance of the solar pond. This note addresses the technique to remove heat from ground and shows the enhancement of the heat removal and efficiency in doing so. Thermal performance of solar ponds is investigated and compared for the cases where the heat extraction fluid (HEF) flux through the LCZ and ground is constant and when they are different. Results show that constant HEF flux through LCZ and ground is a preferable option for heat removal. Also it is evident that the heat recovered from ground may reach a significant quantity which may almost be equal to the heat extracted from LCZ. Hence not recovering heat from ground leads to loss of upto 50% thermal energy.