Simulation Research Of In Internally Cooled Dehumidifier In Solution Dehumidification System

In recent years,with the wide application of a large number of new building decoration materials,indoor building materials continue to volatilize a large number of chemicals and accumulate in indoor spaces,causing great harm to the human body.Therefore,the improvement of indoor air quality through purification technology has become a hot research topic.Among them,photocatalysis is an effective technology to degrade major indoor air pollutants.TiO₂ nano-photocatalyst can decompose and oxidize pollutants such as formaldehyde into odorless and harmless products such as CO₂ and H₂O under normal temperature and pressure conditions,and reduce the concentration of harmful substances in the air.The internal structure of the photocatalytic reactor has been improved.The internal form of fins is used to improve the efficiency of formaldehyde purification.By analyzing the influencing factors such as the concentration of formaldehyde inlet,reaction temperature and humidity,and considering the changes in the pressure field and velocity field in the tube with different fins,Determine the optimal number of fins inside the reactor.First,the oxidative degradation of formaldehyde that occurs in the tubular photocatalytic reactor has two processes:adsorption and desorption and convective mass transfer of pollutants.According to the structural characteristics of the reactor and the reaction characteristics of the catalytic reaction itself,referring to the pulverized coal particle combustion model and simplified formaldehyde catalytic reaction formula,put forward hypothetical conditions,set reasonable simulation parameters,and establish mathematical models.Refer to experimental data in related literature to verify the accuracy of the simulation,The error value within 10%shows that the established mathematical model is reasonable and reliable,and provides a reliable tool for the subsequent simulation research of the formaldehyde purification efficiency of the photocatalytic reactor with different influencing factors.Second,based on a mathematical model,the effects of formaldehyde inlet concentration,reaction temperature,reaction humidity,and purification wind speed on the purification efficiency of formaldehyde were simulated.The results show that the purification efficiency of formaldehyde increases significantly with the increase of the number of fins,but the increase will change with the increase of the number of fins.At low formaldehyde concentration,the concentration of formaldehyde inlet concentration for purification of different number of fins Little effect on efficiency;In the room temperature range,the purification efficiency of formaldehyde basically does not change with the increase of the reaction temperature,but the purification efficiency decreases with the increase of the reaction humidity and decreases significantly with the increase of the purification wind speed.Finally,The change of pressure field and velocity field in tubes with different numbers of fins was studied.The built-in fins will significantly increase the resistance of tube-type photocatalytic purifiers.The greater the number of fins,the greater the pressure drop as the purification wind speed increases.At the same time,the pressure and speed change drastically at the air inlet,and the design should be improved here in subsequent studies.n view of all the above research conditions,the orthogonal test was used to analyze and analyze the relevant influencing factors affecting the purification efficiency of formaldehyde.Three levels of four factors,namely the number of fins,the inlet concentration of formaldehyde,the reaction humidity,and the purification wind speed,were simulated using nine experiments arranged on an（3）orthogonal table.The results were analyzed by range analysis and analysis of variance,and the primary and secondary factors affecting the purification efficiency of formaldehyde were obtained:purification wind speed>number of ribs>formaldehyde inlet concentration>reaction humidity;The optimal level combination A₃B₂C₂D₁ and the excellent level combination A₂B₂C₂D₁ were respectively verified,and the number of internal ribs was finally determined to be 4 in combination with the conclusion of the single factor analysis.The significant influence factor purification wind speed was set as an adjustable factor at 0.2m/s.The new tubular photocatalytic reactor can be used in most indoor air formaldehyde purification environments.