Thermal and infrared camouflage performance of earth-air heat exchanger for cooling an underground diesel generator room for protective engineering

Abstract

Research on earth-air heat exchanger (EAHE) systems focuses on their energy efficiency for civil and industrial buildings. For cooling the protective engineering’s diesel generator room, outlet temperature of EAHE system should be controlled within a certain range close to the outdoor temperature to avoid infrared exposure to military reconnaissance. This study proposed a cooling method for the protective engineering’s diesel generator room by using the engineering’s tunnel as a EAHE. At the beginning, recommended velocity was proposed to meet the infrared camouflage requirement. In addition, influencing parameters including the heat generated in the diesel generator room, soil temperature, and average value and magnitude of outdoor temperature are studied. Also, 3 intermittent modes are simulated. For all simulations, both the cooling capacity and the infrared-camouflage-guaranteed duration are compared. Results show that this system is suitable for small-scale engineering with high average outdoor temperatures and low temperature difference between day and night. The intermittent ventilation significantly improved the infrared camouflage effect while it works but not the total cooling capacity because of the shorter working hours. The infrared-camouflage-protection duration increased by 29.96% as the system intermitted every 9 h, compared with that under non-intermittent ventilation condition.