Computer-Aided Design for Geothermal Heat Pump Sytems

Abstract

Proper design of a ground-loop heat exchanger integrates information about building heat losses and gains (aka: “heat loads”), heat pump performance, geological conditions, loop spacing and pipe size, grout density, drilling depth limits, thermal conductivity and diffusivity ratios of native soil, closed-loop pressure drops and operating energy costs. Optimizing multiple variables benefits from use of software created specifically for the purpose. Basic outputs of ground loop design software include total drilling distance, borehole number and spacing, borehole depth, limits for entering and exiting fluid temperatures at future points in time (i.e., years), circulating pump performance, working fluid density and fluid flow rates. Drilling and borehole data translate directly to drilling contract specifications and pumping data influence interior and exterior system designs.