Comparative study of coefficient of performance (COP) of earth tube heat exchanger (KEY IJP************173)

• Ankur Sharma,Manish Dixit

Abstract

Application of ground coupled heat exchanger (GCHE) systems has been increasing worldwide. They are being utilized in various applications such as space conditioning, water heating, agricultural etc. These systems have the ability to reduce cooling load during the summer and heating load in the winter, providing energy savings and environmental benefits through reduced emissions. Additionally, GCHE systems have the potential to convert a primary energy, making them an attractive solution for sustainable heating and cooling. Experimental and modelling studies play a crucial role in understanding and optimizing the performance of ground coupled heat exchanger systems. These studies provide valuable insights into the performance, efficiency, and limitations of GCHE systems, helping researchers and engineers make informed decisions in system design and operation. Some of the studies reviewed focus on earth-air heat exchanger systems, which involve the exchange of heat between the air in contact with the ground and the surrounding environment. Other studies focus on ground source heat pump systems, where heat is extracted from or injected into the ground for heating and cooling purposes.In this paper we compare the operating parameters effects, i.e. air velocity and temperature, on the thermal performance of a horizontal geothermal heat exchanger (GI tube and copper tube) were investigated. For the tube with a length of 9 m and a diameter of 0.05 m, for the outlet velocity of 11 ms, a temperature drop was observed for GI tubes from 3.930 C - 12.60C in hot weather and a temperature rise for GI tubes from 6oC - 10oC in cold weather, as well as a temperature drop for copper tubes from 3.930C - 12.60C in hot weather and a temperature rise for copper tubes from 60C 100C in cold weather. The system is most efficient to use at higher outlet velocity and maximum temperature difference.