农业工程学报Issue(19)：38-47,10.DOI:10.3969/j.issn.1002-6819.2014.19.005
蒸发式冷凝器喷嘴喷淋性能的数值模拟及试验
Numerical simulation and test on nozzle spraying uniformity in evaporative condenser
摘要
Abstract
In the evaporative condenser, the heat transfer performance was directly influenced by the spraying effect. When the evaporative condenser is in its working state, the cooling water passed through the top spray nozzle, and sprayed uniformly on the outside surface of condenser tubes, and formed a layer of water film. The low temperature water film took away a large amount of heat, the high temperature refrigerant vapor inside the tubes was cooled, and the purpose of the cooling fluid was achieved. In this paper, the spraying effects of two types of nozzles were simulated by CFD numerical calculation software, the real spraying effect was tested on a test platform, and the structure and layout of nozzles were improved at last. In order to get the spraying effect difference of the two types of spray nozzles, the pressure field and velocity field changes were analyzed when the spray nozzles were in different working states. The experimental and simulation results showed that the outer dynamic pressure field of each spray nozzle was irregularly distributed, which was caused by the change of the fluid motion trajectory under the minimum spraying amount. The local dynamic pressure of nozzle two was significantly higher than that of nozzle one. The outer velocity field distribution was directly influenced by the irregular distribution of the dynamic pressure field. The outer dynamic pressure of the two types of spray nozzles were 6000Pa and 13000Pa, and the outer local maximum velocity had reached 3m/s and 5m/s with the water inlet at the velocity of 2m/s. In the simulation, the outer dynamic pressure of nozzle two was always greater than that of nozzle one. The ratio of local dynamic pressure between the two types of spray nozzles was 2.33 when the velocity of water inlet was set to be 3m/s. Compared with spray nozzle one, the condenser cavity static pressure distribution of spray nozzle two was more uniform and reasonable, the local dynamic pressure and spray area were much bigger, and the fluid motion trajectory was simple and clear. The spraying effect could be improved by the design of a shunt channel. At last, the real spraying effect of the two types of spray nozzles was tested on a evaporative condenser test platform. 15 spray nozzles of every type were installed on the water inlet pipeline, and the spraying effect was caught by a high pixel camera when the evaporative condenser was under stable operation state. The water spraying effect showed that spray nozzle two had a much bigger spraying angle and spraying area, and it was better to enhance the spraying effect. In the future study, the internal flow field uniformity of nozzle one can be improved by adding a two-tier shunt platform. Furthermore, the diameter of the shunt base can be increased and more shunt channels can be added on the original base of nozzle two to optimize the spraying water effect and the heat transfer efficiency of the condenser.关键词
数值方法/计算流体力学/喷嘴/蒸发式冷凝器Key words
numerical methods/computational fluid dynamic/nozzles/evaporative condenser分类
通用工业技术引用本文复制引用
朱进林,谢晶,王金锋,杜子峥,周洪剑..蒸发式冷凝器喷嘴喷淋性能的数值模拟及试验[J].农业工程学报,2014,(19):38-47,10.基金项目
2013年国家农业成果转化资金项目（2013GB2C000156）；2013年上海市农业成果转化项目课题 （）
