Thermal modelling and evaluation of borehole heat transfer.

摘要: The use of ground source heat pump systems to provide heating and cooling in buildings has increased greatly in the last decade or so. These have a high potential for energy efficiency, which environmental economic advantages. Moreover, efficiency pump systems can be further enhanced by optimizing performance system. However, key obstacle optimization heat pump is scarcity mathematical models that rapidly, yet accurately, simulate dynamic thermal response borehole system. This study aims develop analytical methods the thermal system time scales from minutes years. An analytical solution model short-time is presented. studies transfer problem Laplace domain and provides an exact radial borehole. A finite-length line-source determine long-term the borehole also presented. used for modelling both single multiple systems. finitelength line-source solutions were combined obtain step-response functions for various configurations are valid from short (hours) long (years) periods. A load aggregation method also presented speed up simulations All proposed models easily implemented any building simulation software optimize overall pump systems. The analyzes various aspects testing and evaluation test facility with nine boreholes was experimental investigations. Several response tests conducted issues include random variations between tests, sensitivity design uncertainties results, convective heat transport boreholes, recovery times after test. evaluations multiinjection rate tests on groundwater-filled boreholes extensively studied. Recommendations regarding each these suggested improve the testing evaluation procedure