Analysis Of Heat Transfer Characteristics Of New Type Heating Terminal Of Air Source Heat Pump

With the gradual improvement of people’s requirements on the thermal comfort of the living environment and building energy efficiency in modern society,a new type of heating terminal,low-temperature skirting board heating terminal has become more and more popular.The main research content of this paper is the heat transfer characteristics of new type heating terminal under the joint heating with low hot water temperature(35-45℃)and auxiliary hot air(0.5-5m/s).The main research process,content and results of this article are as follows.(1)Based on the Fluent software simulation,the heat transfer characteristics of different air inlet and outlet layouts and auxiliary hot air at different air supply angles are studied.Based on the calculation of average air age of the room by UDS function,as well as the temperature gradient of the personnel stay area and the airflow distribution of the room,get conclusion the best air supply angle for the ceiling air supply ceiling air return form is 30° horizontally downward and the best air supply angle for side air supply side air return form is 15°horizontally downward.(2)Based on the best air supply angle,the room temperature,per unit length heat exchange,coefficient of heat transfer,indoor average wind speed under different supply water temperature,new heating terminal height and heating air speed are calculated.The heat exchange formula of the new type heating terminal of air source heat pump was obtained by fitting software,and compared with other literature data to verify.It is concluded that the heat exchange coefficient of the new heating terminal with different water supply temperature can be increased by 8%-21% under the condition that the auxiliary hot air supply air velocity is5m/s.(3)The room PMV index under new heating terminal and auxiliary hot air was studied.It was found that the PMV value increased first and then decreased with the increase of wind speed at different water supply temperatures.The PMV fitting curve in the room was given,it is the functions about auxiliary hot wind speed,inlet water temperature,and heating terminal height.(4)Combined with TRNSYS software,the feasibility of combined heating of solar collectors and air source heat pumps in hot summer and cold winter areas was studied.The indoor PMV index calculated based on TRNSYS software was obtained and compared with Fluent software fitting results for verification.The effect of auxiliary hot air on reducing the thermal inertia of the room was verified.The above research expands the scope of application of the new heating end terminal transfer coefficient formula,conducts in-depth research and analysis on the room temperature distribution and thermal comfort.At the same time simulates the heat source side and the room load side of the heating system to conclude a feasible heating plan.The conclusion of this paper provides theoretical guidance and data support of hot summer and cold winter area in China.