摘要
水平管降膜蒸发器相比满液式具有换热效率高、制冷剂充注量少等优点。文中采用分布参数法建立水平管降膜蒸发换热模型,应用MATLAB软件,对换热管在理想条件下的换热特性进行了数值模拟。研究了光管及Turbo-BII管在管外无干斑发生换热条件下,管外降膜蒸发换热系数、管内对流换热系数、总换热系数、热流密度、降膜蒸发因子、以及换热管单元换热量沿管长方向分布规律,并根据计算结果分析了管间距对换热的影响。该研究为应用于制冷空调领域水平管降膜蒸发器的设计提供理论指导,促进其在制冷空调领域的推广应用。
Compared to flooded refrigerant evaporator, falling film evaporator presents several advantages such as high heat transfer efficiency, small amount of refrigerant, so on. In this paper, a theoretical thermodynamic model with distributed parame- ters was developed for simulating the falling film heat transfer performance, and in this model the effect of film breakdown （ or dry patch） was not considered. In this simulation, two types of tubes were applied including a plain tube and a Turbo - BII tube, and the distribution rule along the inner fluid flow direction of external heat transfer coefficient, internal heat transfer coefficient, total heat transfer coefficient, heat flux, falling film factor, amount of unit heat exchange was obtained. And the effect of tube pitch was also analyzed. This study will be a contribution for the design of horizontal falling film evaporators and promote their ap- plication in the field of refrigeration and air conditioning.
出处
《低温与超导》
CAS
北大核心
2014年第10期68-72,共5页
Cryogenics and Superconductivity
关键词
降膜蒸发
数值模拟
分布参数法
换热特性
Falling film evaporator, Numerical simulation, Distributed parameter method, Heat transfer performance
