Coupled Conditioning Effect On Indoor Hygrothermal Enviroment By Flax Palygorskite Material And Hybrid Radiant Air Conditioning System

Compared with traditional air conditioning system,radiant air conditioning has the advantages of energy saving and high comfort,but it has the disadvantages of insufficient cooling capacity and easy condensation at the radiant end,etc.Combining radiant cooling with fresh air system can effectively solve these problems.Humidifying materials adjust the relative humidity of the room by passive means,thus reducing energy consumption.Humidifying materials and radiation cooling plus fresh air composite air conditioning system can be used in concert to better meet comfort requirements on the basis of reduced energy consumption.Therefore,this paper takes radiation plus fresh air compound air conditioning system and moisture regulating materials as the research object to study the synergistic effect on indoor temperature and humidity,and the main research contents are as follows:Firstly,gypsum,wollastonite and flax fiber were used in the mass percentages of50%:45%:5%to make a thorough mixture and poured into a mold to make a0.5m×0.5m×0.03m moisture regulating material board,in which gypsum was used as a binder to improve the mechanical strength of the composite material.In the climate chamber for actual measurements,respectively,measuring the indoor temperature and humidity changes under the conditions of not starting any equipment,only laying moisture regulating materials,starting the composite air conditioning system and laying moisture regulating materials and adding heat and humidity sources,the area of moisture regulating materials laid 7.5 m~2.experimental results show that when not open the radiant cold plate plus fresh air conditioning system,compared with the case of not laying moisture regulating materials,laying moisture regulating materials The overall indoor relative humidity of the working condition is about 3.3%lower,the indoor temperature of the two working conditions is basically the same,both above30℃;in the case of turning on the radiation cooling plate and fresh air conditioning system,compared to the case of not laying moisture regulating materials,the indoor temperature of the working condition of laying moisture regulating materials is about0.4℃higher,the overall relative humidity is about 2.3%lower,and in the time period of the air conditioning system work,the temperature and relative humidity fluctuation range has also been decreases.The humidity regulating materials in cooperation with the radiation composite air conditioning system can reduce the discomfort caused by the excessive vertical gradient of temperature and relative humidity,and can further improve the indoor thermal comfort.Then Fluent software was used to numerically simulate the distribution of indoor thermal and hygroscopic environment in the room without and with moisture regulating materials under two air conditioning supply methods,namely displacement ventilation and apposed jet air supply.The results show that when the moisture regulating materials and radiation plus fresh air composite air conditioning system work together,indoor thermal comfort can be ensured and the risk of condensation at the end of the radiant cold plate can be reduced.Replacement ventilation conditions indoor space airflow velocity in 0.2m/s,attached to the jet air supply indoor airflow velocity is larger,in the personnel activities of the part of the regional airflow velocity reached 0.35m/s,will cause a certain sense of blowing wind.And as the proportion of moisture transfer material laying area increases,the more obvious the reduction of indoor relative humidity.Through the comparative analysis of the changes in the relative humidity of different sections under different working conditions,it is found that the relative humidity near the wall decreases most significantly.Finally,Energy Plus software was used to conduct a dynamic simulation study of the flax wool material synergistic radiation composite air conditioning system,after the laying of composite moisture regulating materials,the indoor air dew point temperature was reduced,and the peak and valley values of indoor relative humidity were changed to varying degrees,when the composite moisture regulating materials were laid on three walls,the overall indoor air dew point temperature decreased by1.2℃,the maximum peak indoor relative humidity can be reduced by 5.4%,the highest valley value can be increased by 3.2%,that is,the overall fluctuations reduced by 8.6%.Humidity regulating materials synergistic radiant cooling composite air conditioning system can greatly reduce indoor relative humidity,maintain better indoor thermal comfort,and better anti-condensation effect.For hot and humid areas,it provides a new way to create a more comfortable indoor thermal and humidity environment with better comfort and energy saving.