CFD modeling of airflow inside unloaded evaporative cooler, Coolbot-air-conditioner and combined operations

摘要

The cooling of unloaded storage rooms is critical to determine the heat and mass transfer that takes place inside the storage chamber that is later loaded with fresh produce, to establish the theoretical background in the design process. The computational fluid dynamics (CFD) models can provide a good display of the qualitative visualization of the airflow distribution inside storage chamber. The purpose of this study was to simulate the air velocity and air distribution inside unloaded low-cost coldstorage chamber. Therefore, the airflow inside the empty low-cost evaporative cooler (EC), the CoolBot-air-conditioner (CBAC) and the combined operation EC+CBAC was simulated, using CFD models. The steady state with the isothermal model was used to study the airflow inside the storage chambers subjected to EC, CBAC and EC+CBAC cooling. The results showed that airflow distribution was not uniform inside the storage chamber under all the three cooling methods. However, relatively-speaking, the EC+CBAC was found to be the best in its uniformity of the air velocity and distribution, which was followed by the CBAC and EC, respectively. A validation of the models was performed by comparing the experimental air velocity with that of the computed air velocityat different positions inside the storage chambers. The models fitted well to the experimental velocity values and also enabled them to clearly characterize airflow patterns in the storage chamber. This study clearly showed that CFD modeling is a novelway of identifying the airflow inside cold storage and, hence, it was found to be an appropriate tool, not only for advanced design technology, but also for low-cost technology design. Based on the results obtained in this study, the optimal design of cold storage chambers is required to ensure the uniformity of air distribution and air velocity, using computational fluid dynamics modeling.