Thermal performance of helicopter air conditioning system with lube oil source (LOS) heat pump

A helicopter needs to ensure its cockpit temperature in various hot and cold weather conditions. However it is not economical to use engine bleed air to heat the cockpit cabin air in a cold day, while a large amount of waste heat is produced by its lube oil system. In order to utilize helicopter airborne energy efficiently, a conception of air conditioning system with lube oil source (LOS) heat pump is proposed in various weather conditions in this paper. The system can work as an air conditioner cooled by ram air in the cooling mode, and a heat pump warmed by waste heat produced by the lube oil system in the heating mode. A simulation system is correspondingly built to analyze its waste heat utilization and cockpit temperature control performance for a helicopter cockpit in various weather conditions. The results show that the proposed helicopter air conditioning system with lube oil source (LOS) heat pump has a high environmental adaptability, and the system is able to control the cockpit cabin temperature to the comfortable temperature range of 20–28 °C when the atmospheric temperature at take-off is between −40 °C and 40 °C. The coefficient of performance in the whole flight process is 3–6 when the atmospheric temperature at take-off is 40 °C, while the heating coefficient are 3–7 and 2–3 when the atmospheric temperature at take-off are 0 °C and −40 °C, respectively.