Back to Search
Start Over
Performance evaluation and optimization design of deep ground source heat pump with non-uniform internal insulation based on analytical solutions.
- Source :
-
Energy & Buildings . Dec2020, Vol. 229, pN.PAG-N.PAG. 1p. - Publication Year :
- 2020
-
Abstract
- • A new analytical model is proposed for deep geothermal systems. • New observations in non-uniform insulated system in cooling mode. • Turning points are identified when non-uniformity of insulation is investigated. • Multi-factor based evaluation is performed based on orthogonal test design. Deep borehole heat exchanger (DBHE) based ground source heat pump (GSHP) is a promising system for geothermal energy application in medium-deep layer. In this study, DBHE with non-uniform pipe insulation is proposed and numerically investigated. An effective analytical model is built based on segmented finite line-source method and a newly derived water heat transfer model. The year-round field test data are used for model verification. In-depth analyses are given to a comparison between the uniform and non-uniform insulation cases in both heating and cooling modes, and sensitivity analysis on non-uniformity of insulation. A orthogonal test is conducted for energy performance evaluation and optimization. It is found that DBHE with non-uniform insulation can outperform the one with full insulation in cooling mode, which offers new insights. In addition, an optimum insulation length can be identified through the non-uniformity analysis on insulation. It shows that the order of influence factor is heating season duration ratio, flow rate of working fluid, material thermal resistance non-uniformity of the center pipe, pipe sizing ratio, borehole depth, and insulation length non-uniformity of the center pipe. By choosing the proper system design parameters, the system energy saving could be up to 21.8%. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 03787788
- Volume :
- 229
- Database :
- Academic Search Index
- Journal :
- Energy & Buildings
- Publication Type :
- Academic Journal
- Accession number :
- 146681594
- Full Text :
- https://doi.org/10.1016/j.enbuild.2020.110495