Performance of a Small-Scale Direct-Expansion GSHP System during the Winter Operation
- Key words
- Direct-expansion ground source heat pump; performance test; COP; spacing heating; ground heat exchangers
- Location
- Jinzhou, China
- Conference
- Geothermal Resources Council Transactions
- Year
- 2012
- Session
- Geothermal heat pumps; Space heating/cooling; Equipment desi
- Language
- English
Abstract
This paper designs a small-scale experimental direct-expansion ground source heat pump system for space heating. It uses R22 as the refrigerant, consisting of four 20m-deep single U-tube copper ground heat exchangers in clay soils. Its preliminary operation performance and energy efficiency in the heating mode is tested. Results show that the design of the present DX-GSHP system is reliable and effective. During the heating period, when the heating capacity of the indoor coil fan is 6.41kW, the room temperature varies from 18 oC to 20oC even if the door is opened or closed frequently. The average COP of the heat pump and the whole system are 3.12 and 2.88, respectively, and the average heat-transfer rate of GHEs per depth is 54.4W/m. The present results can provide guides for further improvement on the design of DX-GSHP systems in future.
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