CFD Simulation of the Airflow, Heat and Mass Transfer in Latent Heat Exchanger with Segmental Baffles and Its Optimization

摘要

The agricultural greenhouses are aimed at creating a microclimate that is favorable to the growth of plants . A solar heating combined with a latent thermal energy storage system make it possible to make the utmost of solar energy efficiently in the extrame cold winter with low fuel consumption. In this paper, a shell-and-tube heat exchanger was selected as the heat storage component because of the advantages of low cost, simple structure good heat exchange efficiency. Hot air from the solar heater will flow through the shell side of the heat exchanger while the PCMs in the tubes will be heated. A 2D and a 3D numerical model based on computational fluid dynamics (CFD) software were established to simulate of phase change process during the charging period with different input parameters. The 2D calculation shows the melting process of the PCM tubes and the influence of the tube layout, while the 3D calculations are in order to assess the relationship of the baffle numbers and the air temperature. In this respect, the models can be regarded as a valuable assistant for optimize the latent heat exchangers.