The Study Of Film Evaporation Performance Of Composite Pipe With Low Fin

The round tube and elliptical tube are often used in film evaporator. Due to the smaller heat trancefer surface, film evaporator need to maintain a higher amount of water and the heat transfer tube is easy to corrode or scale, which lead to the reduction of equipment life and the increase in investment costs. Applying a new type composite pipe with low fin in film evaporator could efficiently increase the heat transfer area of the tube, and film evaporator will achieve higher heat transfer efficiency without the cooling water in lower ambient temperature. It can reduce the annual water demand and prolong the service life of heat exchange tubes. The research content of this paper is as follows.1. The multi-functional experimental device based on PLC control system was developed and the hardware and software were designed from task and controlled object. The testing and computational quantities were automaticly collected and processed with central processing unit and constant hest for high-temperature medium was achieved by PID controoler.2. The spray density and wind velocity affected the heat transfer performance was tested. Results indicate that the heat transfer performance is affected obviously by the air speed and spray density. The comparison with the data of low finned tube and smooth tube shows that the heat transfer efficiency can meet the requirements with less water in low temperature and less air in high temperature. The low finned tube used in the evaporative cooler has obvious advantage in energy saving.Through this study, a theoretical and experimental basis was provided for low finned tube used in film evaporator, which means that the new type of low fin tube is feasible to replace round tube used in evaporative cooling equipment.