Analysis Of Distribution Characteristics And Influencing Factors Of Ambient Temperature Field In Buildings In Northern China

Today,with high socio-economic development of China,urbanization construction and industrialization development proscess accelerated,China’s total energy consumption has increased significantly,of which building energy consume a relatively large share of energy.Building operation energy consumption is the emphases of building energy efficiency,it will increase with the use of building,of which HVAC consumes about 60% of the total building energy consumption.In the field of HVAC,how to start from the user’s energy consumption side,not only to ensure indoor comfort but also to achieve building energy-saving operation,will be a research hotspot under the carbon peaking and carbon neutrality goals.Therefore,this paper uses a combination of simulation and experiment to study the indoor temperature field distribution characteristics based on an office in northern China,analyzing the effect of different factors on room temperature.and carry out a simulation analysis of the temperature deviation between the indoor working area and the thermostat.Qualitative and quantitative analysis of the changes in room temperature under the combined effect of multiple factors.The relationship between different factors and room temperature was obtained.The relationship between different factors and the temperature deviation between the room temperature and the thermostat were also obtained.Firstly,this paper takes an office in northern China as the research object.Based on the actual structure of the office,on the basis of the theory of fluid mechanics to build mathematical model of the indoor temperature field simulation.The accuracy of the model was verified by comparing the measured and simulated values,and the model error was within 2℃.At the same time,a simulation analysis study on the influence of two factors,window-to-wall ratio（WWR）and building orientation,on indoor temperature was carried out.The simulation results show that the larger the WWR the higher the room temperature.When the room faces east and south,the room temperature is lower,about 20.5℃ in the large room,and about 18℃ in the small room;when the room faces west and north,the room temperature is higher,and the large room is about18℃.It is about 24℃,and the small room is about 26℃.Large rooms have greater thermal inertia,and workers in large rooms are more thermally comfortable.Secondly,in considering the temperature distribution characteristics in the office and validating the established office calculation model,an indoor temperature measurement system was constructed.And the distribution of indoor temperature field during office heating and cooling is analyzed through experiments.According to the experimental data,when the fan coil unit is heating,the vertical temperature difference and temperature fluctuation coefficient are the largest,the air distribution in the upper part of the room is disturbed greatly,and the temperature near the floor is low;When heating by radiant floor or radiators,they have a relatively low vertical temperature difference and temperature fluctuation coefficient,it has uniform indoor temperature field distribution and high comfort during radiant floor heating;when heating with radiators,the area near the radiator has high temperature and poor comfort.Finally,in view of the change of room temperature under the comprehensive action of multiple factors and the temperature deviation between the working area and the thermostat,the room temperature distribution under the comprehensive action of four factors,including outdoor temperature,AC temperature,AC wind speed and WWR,was analyzed quantitatively.The relationship between the four factors and the room temperature,and the relationship between the factors and the temperature deviation between indoor temperature and thermostat.Through the multiple linear regression analysis of the simulation results,four groups of relational expressions were obtained.The results show that the AC wind speed and the WWR have the greatest influence on the room temperature in summer.The AC wind speed is negatively correlated with the indoor temperature,and the WWR is positively correlated with the indoor temperature.The temperature deviation between the thermostat and the working area is about 1°C;the WWR has the greatest impact on the indoor temperature in winter.For each increase of the WWR by 0.1,the room temperature rises by about 0.5°C.The AC temperature and AC wind speed have little effect on the room temperature.Outdoor temperature influence on the indoor temperature is minimal.In winter,the temperature of the thermostat is 1～2°C lower than that of the working area.