| In order to alleviate the pressure of the energy problem, we must attach importance to energy saving and emission reduction. With the improvement of request to indoor air quality, the requirement to the volume of fresh air also continuously improves. It forms the contradiction between energy consumption of fresh air and the indoor air quality. Air to air heat exchange ventilator as an effective energy recovery device, is a very good solution to this contradiction. But now the traditional domestic heat exchange ventilators, most of which are forms of cross-flow, and their heat recovery effectiveness can hardly be improved. Usually, transforming it into a new one—counter and cross flow exchange ventilator—to improve its performance. Numerical simulations were carried out Combined with the conclusion of experiment & theoretical analysis, the the efficiency of total heat exchange ventilators was improved in this paper. The main work and conclusions are as follows:(1)Via the analysis of heat and mass transfer mechanism of heat and mass exchange ventilator, a heat and moisture coupling model by second development based on FLUENT was developed to simulate the cross flow heat exchanger. The accuracy of the model is verified by comparing with the experimental results in the same three-dimensional model and experimental conditions. Then, the performance of the traditional cross flow type core body, the cross counter current and the cross flow of the rib core body and the cross flow without rib are calculated. Concluding the influence of the rib on the performance of the core body is obviously.(2)The specific reasons for the influence of the ribs are analyzed by the gas velocity in the flow channel, and the method of evaluating the value of rib is given by evaluating the core COP of the core. It is found that the existence of internal ribs in the cross flow structure will greatly reduce the energy consumption ratio, but exchange ventilator uninstalled the fin can adapt to the change of different entrance flow angle of the actual working conditions better.(3) Carrying on the optimum design of structure of Cross and Counter FlowPlate Type Air to Air Heat Exchanger by considering the channel height, the length of the upstream section, and the inlet airflow angle of the fresh air exhaust. Optimization conclusion:considering the influence of inlet airflow angle and counter flow length, it is considered that the length of 400mm can be guaranteed when the air exhaust is parallel or perpendicular to the axis, and the core channel should be selected as 3mm. It can provide guidance for the design and installation of the actual core and external diversion.(4) The effects of different operating conditions on the performance of the plate type heat exchanger were studied, The multiple regression analysis was carried out by matlab, the apparent thermal efficiency and latent heat efficiency of the regression equation were obtained. Then turns out the regression effect is obvious. At last, select ing.Tianjin as a representative of the cold area, Shanghai as the representative of the hot summer and cold winter area, analysis of the energy saving effect of the new air system with the optimization of Cross and Counter Flow Plate Type Air to Air Heat Exchanger. The results showed that applied it to the recovery of air conditioning system in cold areas with hot summer and cold winter area is very significant, application in cold regions of energy recovery efficiency is slightly greater than the area with cold winter and hot summer.
|
PDF Full Text Request