Application of a new ventilation system coupling exhaust air heat recovery and air-source heat pump in temporary housings for Olympic Winter Games

In order to ensure the normal progress of Olympic Winter Games, numerous temporary housings have been built in the Olympic Winter Games venues, especially the alpine skiing venues. Traditional temporary housings usually use exhaust fans or natural ventilation as the main ventilation methods. In severe cold climates, the supply air temperature and air distribution can not be guaranteed, resulting in low indoor thermal comfort and high ventilation energy consumption. Based on the concept of green Olympics, a new ventilation system coupling exhaust air heat recovery and air-source heat pump is used in the temporary housing of Beijing Yanqing Alpine Ski Center for 2022 Olympic Winter Games. The actual performance of the system during the Olympic Winter Games is measured， and the results show that the actual average heating performance coefficient of the system and the heat pump during the Olympic Winter Games is 2.1 to 2.8 and 1.6 to 2.4, respectively, and it is an effective energy saving environmental control system. After analysing the indoor and outdoor thermal environment during the Olympic Winter Games, theoretical model of the system is built， and it is concluded that the theoretical average heating performance coefficient of the system and the heat pump is 4.9 to 5.9 and 3.3 to 4.1, respectively，and the actual system still has room for optimization. To further improve system performance and operation stability, internal frosting of heat recovery device under low temperature conditions needs attention, and the enhanced vapor injection low-temperature air-source heat pump and heat recovery device with higher efficiency should be used.