Experimental Study And Numerical Simulation On Frost Problem Of Fresh Air Ventilator In Cold Region

With the development of economy, people's life and habitation condition is continually improving and promoting. Indoor air condition is getting more and more attention. As a new-style indoor air ventilation facility, fresh air ventilator with energy reclaiming has the virtues of improving indoor air quality and energy saving. At the same time, as a new-style indoor air ventilation facility, it also has some shortages, especially in cold areas, heat exchanger of fresh air ventilator has the problem of frost formation, and it affects the use effectiveness of fresh air ventilator.Several essential predigestions supposing for heat Exchanger of cross flow blank was taken out, and based on the heat transfer performance of heat exchanger of cross flow blank, three-dimensional mathematical model had been established. With the preprocessor Gambit, the geometry and mesh generation was completed. Using Fluent the simulation was began based on defining the boundary which was coupled with heat transfer. The characteristic curves and diagrams which described the temperature and velocity field of the cold and hot air channels were presented by the software of Tecplot.In the paper, a series of experiments testing of some type of fresh air ventilator of cross flow blank's running in Harbin were taken out. The thermal efficiency was computed according to the experiment data, and also studied the frost formation of it. Based on the results of numerical simulation, frost area distributing has been studied, and got the connection between the frost area with temperature and humidity of indoor and outdoor. Compare between results of numerical simulation and experiment data showed that they are perfectly inosculated, and this validated reliability and precision of the modeling. After changing the inlet boundary condition with the frost area distributing, more simulation was taken out. The distributing of temperature and velocity was simulated, and it has been studied that the function was perfect under the frost condition, and no frost has been appeared under any temperature condation.