A study on optimization of horizontal ground heat exchanger parameters for space heating application

In the present scenario, space heating/cooling has become essential for human comfort. Most of the demand is fulfilled by conventional devices, which consume high-grade energy and emit toxic gases. Due to this, now focus is turned on how to harness the renewable source of energy is becoming important. In recent times, GSHP systems are very popular for space conditioning applications. The ground heat exchanger (GHX) extracts and rejects the heat from the ground for heating & cooling, respectively. This work is proposed for optimizing the total length of GHX to achieve higher performance of GSHP system by Taguchi optimization technique. Five influencing operating parameters for GHX have been considered using the L₂₇(5³) orthogonal array. Lower the better concept is used for GHX length optimization. The results are investigated through optimum values of ANOVA and S/N ratio analysis. Simulation using L27 orthogonal array were carried out by considering 1.5 ton of total heating demand in wintertime. Based on trial runs, it is found that the minimum and maximum lengths were 12.17 m and 137.55 m, respectively. The optimum length of GHX is 11.05 m, which is 9.17% lower than the value predicted by the L₂₇orthogonal arrays.