Transfer of Low-Potential Heat from a Deep Borehole by Means of a Heat Pipe and Heat Pump

Milan Malcho,Stanislav Gavlas,Andrej Kapjor,Jozef Jandacka,Martin Vantuch

doi:10.26552/com.c.2012.4a.18-22

Milan Malcho, Stanislav Gavlas + Show 3 more

Open Access

https://doi.org/10.26552/com.c.2012.4a.18-22

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Abstract

The paper presents a design of equipment for the usage of low-potential heat collected from rock in a deep borehole by means of heat pipes (HP) and a description of its realization. The borehole model together with a CFD simulation of heat transfer from rock to a soil probe enabled dimensioning of a heat exchanger on the condenser part of the heat pipe and choice of a suitable heat pipe charge. Part of the paper deals with the processing of measurement results gathered from the comparative experimental equipment requiring forced and unforced circulation(heat pipe) of the working substance on the primary side of the heat pump.

Highlights

Low-potential heat of the rock is a heat flow in the surface area of the Earth crust with a relatively low thermal potential corresponding to the standard geothermal gradient
As the outer daily temperatures approached 28 °C, the heat pump control more often turned on and off in short time intervals. This could result in continuous interruption of the process of phase change in the heat pipe which led to heat output drop
G Another possibility which might occur in our case may be unequal dosing of the working substance for individual U tubes of the heat pipe

Summary

Introduction

Low-potential heat of the rock is a heat flow in the surface area of the Earth crust with a relatively low thermal potential corresponding to the standard geothermal gradient. A great advantage of low-potential geothermal heat is that it is not limited by a geothermal region or any region with a high potential of hot geothermal waters It can theoretically be recovered anywhere on Earth’s surface. Heat pipes with suitable charge seem to be a perspective way of collecting heat from rocks without a forced circulation of a working substance In such a system the heat carrier flows in the pipe without additional energy supply with small temperature difference making use of the properties of heat transfer at phase changes. In heat technology heat pipes are used for solar energy transfer in high-efficiency solar collectors and in systems for heat recovery

A design of the heat pipe

Numerical model of heat transfer from the rock into the heat pipe

Measurement of heat pipes output parameters

Conclusion