Numerical Study on System Performance of Groundwater Heat Pumps

Abstract

Groundwater heat pumps have great potential where the groundwater resources are sufficient. System Coefficients of Performance (COPs) are used measures of performance of groundwater heat pump systems. Head and power of submersible pumps, heat pump units, piping, and heat exchangers are expressed in the polynomial equations, and theses equations are solved numerically to find the system performance. Coefficients of polynomial equations are found from product data by using regression analysis. Cooling and heating capacities of water to water heat pumps use EnergyPlus water to water heat pump equations. Results shows that the system performance drops as the water level drops, and the lowest flow rates generally achieve the highest system performance. The system COPs are employed to compare the system performance of various system configurations. The groundwater pumping level and temperature provide great effect on the system performance of groundwater heat pumps along with the submersible pumps and heat exchangers. The effects of groundwater pumping levels, and groundwater temperatures, and the heat exchanger UA values on the system performance are given and compared. The analysis needs to be included in the design process of groundwater heat pump system, possibly with analysis tools that include wide range of product data.