This paper is based on long term parameter measurements of the exhaust air heat pumps (EAHP) system in a new built apartment building. The building was equipped with an exhaust air ventilation system and exhaust air h...This paper is based on long term parameter measurements of the exhaust air heat pumps (EAHP) system in a new built apartment building. The building was equipped with an exhaust air ventilation system and exhaust air heat pump for ventilation heat recover. The results of the measurements show that the COP of the EAHP is mainly related to the temperature graph of the heating system and the supply temperature of domestic hot water (DWH). During the measurement period some other impact factors, such as the quality of maintenance, the nighttime temperature graph of the heating system, the reduction of the exhaust air flows in case of low temperatures, mistakes in designing and low building quality, have also played a role. An analysis of energy consumption shows that in winter conditions the COP is about 3.0 and in the transition period about 3.3. The energy recovery value of the EAHP is 0.5.展开更多
The reasons of introducing cold air into pulverizer are analyzed for boilers with large capacity and high parameters. The temperature rises of the exhaust gas are calculated when varying the amount of the cold air. Th...The reasons of introducing cold air into pulverizer are analyzed for boilers with large capacity and high parameters. The temperature rises of the exhaust gas are calculated when varying the amount of the cold air. The hot primary air heater, a new technology, is developed to eliminate the cold air from the pulverized coal system. The applications, advantages and disadvantages are introduced in detail for the new device and system. It is concluded that introducing cold air into pulverizer is one of the major factors that causes the exhaust gas temperature of boilers with large capacity to be high. The amount of the cold air could be reduced signif icantly, even to zero in some cases by adopting the hot primary air heater, which drops the exhaust gas temperature of the boiler effectively. The hot primary air heater, which could play part roles of the steam-air heater or the hot air recirculation system, could also be used to adjust the exhaust gas temperature within the range of 20 ℃ by controlling the flow rate of the cooling medium. Moreover, the startup period of the steam-air heater or the hot air recirculation system will be shortened, which is a unique advantage of the hot primary air heater among the measures to drop the exhaust gas temperature.展开更多
The location of exhaust air vents of an evaporative cooling system can have significant effects on providing thermal comfort and controlling humidity, temperature and air distribution in buildings. In the current stud...The location of exhaust air vents of an evaporative cooling system can have significant effects on providing thermal comfort and controlling humidity, temperature and air distribution in buildings. In the current study, four different strategies have been evaluated for exhaust air vent locations to provide the optimum thermal comfort inside a typical residential house. This study provides a numerical solution for temperature and relative humidity profiles in the residential house and within the living space in each room typically at a height of 1.8 m or less. By evaluating different exhaust air vent locations in a room, the best strategy(ies) to provide more appropriate thermal comfort condition and obtained and as a conclusion, the exhaust vents should be located on furthest wall away from the entrance of the room and in the middle. The results provided in the current study can eventually be applied in the design of evaporative cooler exhaust vent systems in residential buildings and lead to improve the performance of these systems.展开更多
文摘This paper is based on long term parameter measurements of the exhaust air heat pumps (EAHP) system in a new built apartment building. The building was equipped with an exhaust air ventilation system and exhaust air heat pump for ventilation heat recover. The results of the measurements show that the COP of the EAHP is mainly related to the temperature graph of the heating system and the supply temperature of domestic hot water (DWH). During the measurement period some other impact factors, such as the quality of maintenance, the nighttime temperature graph of the heating system, the reduction of the exhaust air flows in case of low temperatures, mistakes in designing and low building quality, have also played a role. An analysis of energy consumption shows that in winter conditions the COP is about 3.0 and in the transition period about 3.3. The energy recovery value of the EAHP is 0.5.
文摘The reasons of introducing cold air into pulverizer are analyzed for boilers with large capacity and high parameters. The temperature rises of the exhaust gas are calculated when varying the amount of the cold air. The hot primary air heater, a new technology, is developed to eliminate the cold air from the pulverized coal system. The applications, advantages and disadvantages are introduced in detail for the new device and system. It is concluded that introducing cold air into pulverizer is one of the major factors that causes the exhaust gas temperature of boilers with large capacity to be high. The amount of the cold air could be reduced signif icantly, even to zero in some cases by adopting the hot primary air heater, which drops the exhaust gas temperature of the boiler effectively. The hot primary air heater, which could play part roles of the steam-air heater or the hot air recirculation system, could also be used to adjust the exhaust gas temperature within the range of 20 ℃ by controlling the flow rate of the cooling medium. Moreover, the startup period of the steam-air heater or the hot air recirculation system will be shortened, which is a unique advantage of the hot primary air heater among the measures to drop the exhaust gas temperature.
文摘The location of exhaust air vents of an evaporative cooling system can have significant effects on providing thermal comfort and controlling humidity, temperature and air distribution in buildings. In the current study, four different strategies have been evaluated for exhaust air vent locations to provide the optimum thermal comfort inside a typical residential house. This study provides a numerical solution for temperature and relative humidity profiles in the residential house and within the living space in each room typically at a height of 1.8 m or less. By evaluating different exhaust air vent locations in a room, the best strategy(ies) to provide more appropriate thermal comfort condition and obtained and as a conclusion, the exhaust vents should be located on furthest wall away from the entrance of the room and in the middle. The results provided in the current study can eventually be applied in the design of evaporative cooler exhaust vent systems in residential buildings and lead to improve the performance of these systems.
