Feasibility Analysis On Effectiveness Of Ground Source Heat Pump (GSHP) System
Abstract
In the past, people were making the best use of precious resources and wealth such as gold, coal, petroleum products etc from deep within the Mother Earth. In similar lines, under the surface of the Earth, there is a constant temperature heat source prevailing and the temperature does not change throughout the year as reported in literature. The concept of ground source heat pump (GSHP) system capitalizes on this heat source and extracts the thermal energy by circulating a mixture of water and an antifreeze refrigerant in a closed looped piping system buried underground. The heat so extracted is useful for a number of heating applications such as processing fabric in textile industry, cleansing in food processing industry, supplying hot water for residential building and the like. The fluid mixture inside the pipe absorbs the underground heat energy using ground heat collectors and passes through a heat exchanger all the way to the heat pump. Therefore, this system could potentially replace the traditional ways of heating with an environment-friendly heat pump, which is called GSHP. In Oman, there are many heat pump systems using many sources such as gas, air, fuel, electricity etc in service, but only a few use renewable energy sources. This paper aims to do a feasibility analysis using an experimental prototyping on effectiveness and performance analysis of GSHP system. This is done by collecting design variables, analyzing their influence on the GSHP operations, making a small experimental set up and testing its feasibility for use. The working model is made by burying a 3/8” diameter copper pipe at 0.5, 1 and 1.5 m underground as evaporators in order to heat water stored in a cylindrical tank. From the testing of prototype results, it was observed that the temperature of the refrigerant entering the water tank was in the range between 30oC and 47.8oC and at the exit point 27.3oC and 28.1oC. The feasibility analysis undertaken in this work and the results obtained thus confirm that GSHP could be a potential alternate means to conventional heat pump systems. Other advantages, beside the use of renewable energy, of GSHP include (i) produce less noise, (ii) cheaper running cost, (iii) environment friendly system, and (iv) minimal maintenance of the system.
