Analysis Of Solar Heating Characteristics Using Radiator In Kunming Area

With the improvement of people's living standard,the heating demand in winter is increasing.Because of the large temperature difference in the morning and evening in winter,the temperature in the low latitude plateau area,including Kunming area,is relatively low,and the heating application is also increasing in recent years.Kunming area is rich in solar radiation resources in winter.If we can make full use of the abundant solar energy in Kunming area for heating design,it can not only effectively improve the residential thermal environment in buildings,but also save energy and improve the use of solar energy.In this paper,a solar heating experimental room is built in Kunming as the research object.A series of experiments and numerical simulation calculation and analysis are carried out by using radiator heating,which provides data support and engineering reference for the practical application of solar heating in Kunming.The specific contents are as follows:First of all,the experimental room is built according to the actual situation of Kunming.In order to study the influence of heating system on indoor thermal environment,four experimental conditions are designed.The first condition is to conduct external sunshade treatment and no heating for the experimental room,the second condition is to conduct external sunshade treatment and heating for the experimental room,the third condition is not to conduct sunshade treatment and heating,the fourth condition is rainy weather and no heating,and part of the working conditions try to exclude the solar radiation from the indoor thermal ring Environmental disturbance.In this paper,PMV(predicted mean vote)and PPD(predicted percent)are introduced Then the indoor air temperature curve with outdoor air temperature,indoor air temperature nonuniformity,indoor PMV-PPD at different times,the relationship between heating capacity and outdoor air temperature function,the relationship between heating capacity and indoor temperature rise function are obtained by analyzing the experimental data.The results show that the meteorological data of the first three working conditions are similar,all of which are local typical meteorological environment data of Kunming.There is a heating demand at night for about 13 hours without heating,and the heating demand is large,the percentage of dissatisfaction PPD reaches 78,the indoor air temperature has a good uniformity at night and a bad uniformity in day,and the comfort degree of the whole day after heating belongs to the specified range,and the indoor air temperature has a good uniformity;Under the condition of no sunshade heating,the comfort degree at night belongs to the specified range.During the period of high solar radiation in the daytime,the indoor air temperature increases,resulting in poor comfort degree and good indoor air temperature uniformity.In rainy days,the temperature fluctuates less in the whole day,which is 2?,and the average temperature is lower.The heating demand of the whole day has poor thermal comfort,and the percentage of dissatisfaction PPD is between 35-60.The indoor comfort is the best under the condition of sunshade and heating.Through the calculation of the heat supply of the collector and radiator,the data of the heat supply of the radiator,the indoor air temperature and the outdoor air temperature are analyzed.The lower the outdoor air temperature is,the greater the heat supply is needed.Through the fitting analysis of the experimental data,the regression relationship between the outdoor air temperature and the heat supply of the radiator is obtained.On the basis of the experimental data,the numerical simulation of the laboratory was carried out by the Airpak software in CFD(Computational Fluid Dynamics).After the accuracy of the numerical model is verified,16 schemes of radiator not heating,radiator temperature of 45?,50?,55?,60?in typical weather and rainy weather,radiator under north wall,east wall,east window,south window,west wall and south wall are simulated and analyzed by CFD method.Through the analysis of the simulation results,it can be concluded that:(1)under the typical weather and rainy weather,the 60?radiator has the best indoor thermal comfort,the lower the heating temperature is,the worse the thermal comfort is.Under the rainy weather,different radiator temperatures of 50?,55?and 60?can guarantee the whole day thermal comfort,and under the typical weather,the 60?radiator temperature can guarantee the whole day thermal comfort;(2)the higher the radiator temperature is,the worse the indoor thermal comfort is The more stable the air temperature is all day;(3)the greater the temperature difference between indoor and outdoor,the greater the temperature difference between indoor vertical direction and horizontal direction;(4)the higher the temperature of radiator,the greater the temperature difference between indoor vertical direction and horizontal direction;(5)the best thermal comfort of radiator under the east window,the worst thermal comfort under the south wall,the temperature difference between the best position and the worst position is 0.9,PMV difference is 0.147,PPD phase The difference is 2.8.Finally,polysun,a renewable energy design and optimization software,is used to simulate different schemes of solar heating system.It is found that(1)increasing the collector area and water tank capacity significantly increases the solar energy guarantee rate,but has little impact on the unit area load.For every 3.72m~2 of collector area and 250L of water tank,the increase range of solar energy assurance rate is 2.60%-11.30%,and the scheme with collector area of 11.16m~2 and water tank capacity of 750L has the lowest unit area load;(2)the higher the room heating demand temperature,the greater the total energy demand,the higher the unit area load,the lower the solar energy assurance rate,the increase of heat pump supply and the increase of power consumption.When the room heating demand temperature is from 19?to 20?,20?to 21?,21?to 22?,the unit area load increases by6.00kwh,11.81kwh and 1.00kwh respectively.(3)In the heating season,the solar energy assurance rate is the lowest in January and December,and higher in February;(4)changing the angle of collector and radiator area has little effect on solar energy assurance rate and unit area load.