Operational proposal of “U” type earth heat exchanger harnessing a non-producing well for energy supply to an absorption cooling system. Approach with “La Primavera” geothermal field data

Abstract

This paper proposes the operation of “U" type heat exchangers to harness the remaining heat/geothermal energy in a non-producing well and use it in an absorption cooling system. The operational proposals are obtained with a previously validated numerical model that allows modifying geometric and functional parameters of the heat exchanger, in addition to considering information from the well and the absorption cooling system to estimate the temperature of the fluid along the tubes. By taking information from the well, such as the geothermal gradient, the thickness of each stratum, and its thermophysical properties, in addition to the requirements of the absorption cooling system, it is possible to reach more realistic results compared to omitting or assuming any information. In total, 31 different simulations were carried out in which one of the following five parameters was modified: fluid velocity, diameter and total length of the heat exchanger, thickness and length of the insulating material. As a result, 4 different operation proposals are obtained that meet the requirements of the absorption cooling system. In this way, it is possible to combine in a novel way the properties of the well, the characteristics of the absorption cooling system, and the operating parameters of the “U" type heat exchanger.