Heat and mass transfer model of a Ground Heat Exchanger: theoretical development

✍ Scribed by M. Piechowski

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 196 KB
• Volume: 23
• Category: Article
• ISSN: 0363-907X
• DOI: 10.1002/(sici)1099-114x(19990610)23:7<571::aid-er462>3.0.co;2-6

✦ Synopsis

A new approach to the simulation of a horizontal type Ground Heat Exchanger is proposed resulting in a better accuracy and at the same time a reduced computational e!ort. These results come from the concentration of the computational e!ort at the locations with the largest temperature and moisture gradients, i.e. the pipe}soil interface. The model takes into account heat and moisture transfer in the soil allowing for more accurate predictions of the soil thermal response to the heat #uxes induced by the GHE operation. This in turn allows for a more accurate prediction of the soil temperature "eld and the circulating #uid temperature pro"le. A comparison of the results obtained by using the implicit and explicit methods of solving the set of governing equations is discussed. The implicit method requires partial linearization of the heat and mass transfer equations but results in a considerably shorter simulation time. The explicit formulation allows for the solution of the fully nonlinear set of heat and mass transfer equations at the expense of increased simulation time.

The following analysis shows that the di!erence between the solutions obtained using these two methods is minimal, thus favouring the implicit formulation.