A thermal insulation layer between the horizontal ground heat exchanger and ground surface was proposed to reduce the infrared exposure risk of the ground source heat pump system in handling the waste heat of protective engineering. The insulation layer model of spiral-type horizontal ground heat exchanger was developed to compare the surface temperature distribution with or without insulation layer under typical working conditions, analyze the infrared camouflage effect resulted from the insulation layer, and evaluate the incidental influence of the thermal insulation layer on the thermal performance of the system. The results show that by laying the thermal insulation layer, the maximum temperature difference between the surface above the buried pipe and the surrounding area can be reduced from 5 ℃ to less than 0.3 ℃, and the infrared exposure risk of the system is greatly reduced. By installing the insulation layer, the average COP of the heat pump and the system can increase by 0.15 and 0.09 respectively, and the system thermal performance can be improved. When the surface heat flow above the buried pipe, the outlet temperature of the buried pipe, and the surface heat flow or temperature difference between the surface above the buried pipe and the surrounding area are extreme values, the infrared camouflage processing of the system should be emphasized.
Key words
ground source /
numerical models /
thermal efficiency /
infrared exposure /
countermeasures
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