| Energy saving and emission reduction have become the basic national policy of our country.The increasingly serious haze phenomenon in winter also urges us to respond positively to the call of clean heating and contribute to the haze control.Clean heating involves heat source,transmission and distribution network and heating users(terminal room).For the terminal room,because of the heat storage and release function of building heating room and the preheating process and waste heat release process of heating equipment,the actual temperature fluctuation of room heating on-off control operation exceeds the temperature range of room design,which not only affects the comfort of users,but also wastes energy.This paper mainly studies the phenomenon of room temperature delay and overshoot in room heating,to improve the control strategy of heating terminal and optimize the room temperature control effect.On the basis of building comprehensive thermal inertia,the index parameters of room heating thermal inertia are formulated.The influencing factors of room heating thermal inertia are analyzed,and the experimental study on the influence of outdoor environmental factors(outdoor temperature,solar radiation)and different heating terminal forms on room heating thermal inertia is carried out.On this basis,a method of improving terminal on-off control by using index parameters is proposed,and the improved heating experiment is carried out.The TRNSYS(Transient System Simulation Program)model of multi-area building and room heating control system is established to analyze the influence of different window-wall ratio,different orientation and shading on room heating inertia.The results show that:1)Overshoot temperature difference and lagging temperature difference in heating room temperature control are fluctuations.Overshoot temperature difference is positively correlated with winter outdoor environment temperature and solar radiation intensity,while lagging temperature difference is negatively correlated with outdoor temperature and solar radiation intensity.In the same control cycle,the value of overshoot temperature difference is obviously larger than that of lagging temperature difference.2)The actual opening and closing temperatures of the terminal controller can be well controlled within the designed temperature range by adjusting the characteristics of the overshoot temperature difference and the lagging temperature difference.3)The window-wall ratio,orientation and shading of a room will affect the thermal inertia index parameters of the room,but they all depend on the intensity of solar radiation.Therefore,the factors above noon have a greater effect on the overshoot temperature difference and the lag temperature difference,and the effect at night can be neglected.Consequently,the influencing factors of room heating thermal inertia are complex and changeable.Studying the influencing characteristics of each factor and formulating appropriate characterization parameters to improve the setting parameters of terminal controller is an effective way to achieve good temperature control in heating room. |
