Investigation of parameters effecting performance of a ground source heat pump

ABSTRACT Master Thesis INVESTIGATION OF PARAMETERS EFFECTING PERFORMANCE OF A GROUND SOURCE HEAT PUMP Hikmet ESEN Fırat University Graduate School of Natural and Applied Sciences Department of Mechanical Engineering 2002, Page: 83 The heat pumps are generally an application of vapor compression refrigeration systems where the rejected heat from the cycle is used as a heat supply and the added heat is taken from a cold source. Optimum performance is achieved as the amount of work required for a specified amount of heat delivered to the higher temperature region is rrunimized. The heat pump can be designed to operate as an air conditioner in warm seasons and a heating unit during the colder seasons. Ground source heat pump systems are usually used for heating or cooling of commercial and residential buildings. In general, temperature of the soil almost during the year is stable; however, temperature of the soil greatly affected by the type of soil and moisture content. The present study had the goal to validate the effects of the parameters such as the depth of earth coupled heat exchanger, and the mass flow rate of the brine on the performance of a ground source heat pump used for space heating experimentally. In addition, a theoretical model had been developed to determine the temperature distribution in the soil. The finite difference approximation is used for numerical analysis. It is observed that theoretical results agree with the experimental results. The experimental results performed in Elazığ indicate that the horizontal heat exchanger with depth of 2 m gives a higher heat pump performance than the depth of 1 m. The results also show that increasing of the mass flow rate of the brine increases the electric power required to work heat pump and consequently decreases the COP of the heat pump. Key Words: Ground source heat pump, theoretical model, experimentally performance XTV