Study On Application And Operation Optimization Of Low Ambient Temperature Air Source Heat Pump Air Heaters In Northern Rural Areas

In order to reduce the environmental pollution and energy waste caused by the inefficient combustion of loose coal,the northern region is pushing forward the"coal to clean energy"project on a large scale in recent years.Among the many technologies to replace the coal combustion and heating,the low ambient temperature air source heat pump air heaters has been widely applied in the rural areas of northern provinces due to its characteristics of low initial investment,convenient installation and flexible operation.At present,a few studies have been carried out on its heating operation,but there is still a lack of feedback from users on its actual heating effect and evaluation of the system’s heating effect.At the same time,the low ambient temperature air source heat pump air heaters also has the refrigeration function,which has been used by a large number of users in the summer,but there has been no field test on the refrigeration effect of the unit.This paper conducts research on the above issues,and the main research contents are as follows:(1)Two typical households were selected based on the clean heating operation effect monitoring platform.Through the analysis of the monitoring data of the two typical households,the heating effect of the low ambient temperature air source heat pump air heaters in winter can be seen.During the heating season,on the coldest days,the outdoor temperature is respectively-12.9℃and-16.6℃,while the average indoor temperature is higher than 18℃.The unit operates stably,which can well meet the requirements of users for thermal comfort and provides good heating effect.During the monitoring period,the no.1 demonstration household adopts the mode of uninterrupted operation throughout the day.In the heating season,the total power consumption is 5959kw·h,and the power consumption per unit heating area is118kw·h/m~2.As the representative of intermittent operation mode,the no.2demonstration household consumes a total of 2030kw·h in the heating season,and29k W·h/m~2per unit heating area.The total heating cost is 504 yuan.The heating costs are low.(2)A questionnaire was designed to understand the feedback of users on the heating effect of the low ambient temperature air source heat pump air heaters in winter.The results showed that more than 90%of the users said the room temperature was above 18℃,and more than 30%of the users said the indoor temperature was above 22℃.More than 83%of users said they thought the heating cost was more economical.More than 90%of the users said that the dry feeling,blowing feeling and noise caused by the low ambient temperature air source heat pump air heaters during heating are within the acceptable range,or even no feeling.(3)Through field performance test,analyze the cooling effect of the low ambient temperature air source heat pump air heaters in summer.The results show that the average energy efficiency ratio of the unit can reach more than 3.0 in a variety of working conditions,the operation is stable,can meet the needs of room refrigeration,and the refrigeration effect is good.When refrigeration can create more appropriate room temperature and good room temperature distribution.The low ambient temperature air source heat pump air heaters can be used as the choice of room cooling in summer.(4)A questionnaire was designed for the use experience in summer to understand the users’comfort feeling for the cooling effect of the low ambient temperature air source heat pump air heaters in summer.The results show that the use rate of room cooling in summer is higher than 60%among the users with the low ambient temperature air source heat pump air heaters.96%of users are satisfied with the overall cooling effect,and most users are concerned about the cooling cost.More than 90 percent of users were unaware that the downdraft of the hot fan could be switched on and off,while 67 percent were unaware that the indoor units needed to be regularly dedusted.These investigation results have reference significance for the extension of the low ambient temperature air source heat pump air heaters.