| The heat transfer coefficient and thermal inertia of building enclosure structure respectively characterize the heat insulation of enclosure structure and the ability to resist the fluctuation of outdoor temperature.Low heat transfer coefficient and good thermal inertia of enclosure structure can effectively reduce the energy consumption of building operation and improve the stability of indoor thermal environment.At present,the experimental study on heat transfer coefficient of enclosure structure is mainly carried out by using cold and hot boxes,while the thermal inertia is mostly taken from the field,and a building is taken as an object for study.This research method has many interference factors and can only passively select meteorological conditions.Therefore,it is of great significance to develop an experimental system which can simulate the dynamic changes of temperature and humidity in real room and outside for the research of thermal insulation and thermal inertia performance of enclosure structure.In this paper,an experimental system of dynamic response of indoor thermal environment with periodic outdoor winding is developed.By simulating the actual outdoor temperature and humidity changes,the experimental system explores the influence of thermal insulation and thermal inertia of different envelope materials on the dynamic changes of indoor temperature.The research work is as follows:According to the functional requirements of the experimental system,the overall structure design is carried out,and the zonal temperature and humidity control scheme with separate and independent control for different areas is determined.The indoor area envelope structure can be replaced according to the experimental requirements to realize the experimental study on the thermal performance of various envelope structures.The optimum design of air system and water system is studied.According to the characteristics of climate distribution in China,the extreme climatic conditions simulated by the experimental system are determined and the cold,heat and humidity loads are calculated.Based on this,the equipment selection of the air system is completed,which ensures the ability of the air system to create various experimental conditions,especially the extreme conditions.According to the requirement of temperature field and air distribution uniformity of indoor and outdoor environment,the fluent was used to carry out simulation analysis and optimize the number and arrangement of air supply and return outlets in the air system.For the water supply demand system of the end equipment,cold and hot water are produced by chiller and electric heating respectively,and stable cold and hot water supply is provided for the end equipment by relay water tank.Determine the control parameters and scheme of the automatic control system,output the data acquisition value based on the PID control logic and feed it back to the parameter input terminal,then adjust the operating power of the terminal equipment by the controller to balance the deviation,so as to achieve a high-precision closed-loop control of indoor temperature and humidity,water temperature and flow,in which the instantaneous temperature deviation is less than 0.3 C and the humidity deviation is less than 3% RH.The deviation of water temperature is less than 0.2 C and the deviation of flow rate is 0.03 m.~3/ H;Connect the analog input of PLC and industrial computer with the data acquisition system integrated with the data collector and controller to acquire and record data efficiently once per second.At the same time,in order to ensure the safety of the experiment,interlock protection mechanism is set for the equipment requiring opening and closing sequence,and fusing device is installed for the high-power equipment to ensure the safe and efficient operation of the system.Adjust and test the experimental system and each end equipment to verify that each performance of the experimental system meets the requirements of the experiment.Through the test after debugging,it is found that the system can maintain the control of extreme temperature for more than 48 hours,the maximum average deviation under the test conditions of steady-state temperature and humidity is 0.04 C,1.6% RH,and the maximum average deviation of water temperature and flow is 0.13 C and 0.018 m,respectively.~3/ H;Under unsteady test conditions,the dynamic response speed of room temperature and humidity to parameters can reach 10 minutes/time.The dynamic response test of indoor temperature under periodic change of outdoor temperature is carried out on the test bench.Taking outdoor and interior space environment of the experimental system as object,a model is established.The indoor temperature change under the same conditions is simulated by Energy Plus,and the accuracy of the model is verified by comparing the simulated data with the experiment.On this basis,the thermal insulation mode of the envelope structure and the insulation material of the model are changed to simulate.The simulation results show that the thermal insulation mode of the external insulation is the best under the same thickness conditions,while the extruded polystyrene board maintains the best indoor temperature stability under the same thermal insulation mode.There are 80 figures,18 tables and 62 references. |
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