摘要
以管内介质有相变的翅片管空气冷却器为研究对象,采用量纲分析、泛函分析等方法,构建了一个合理的翅片管空气冷却器传热系数关联式。以氨泵供液型空气冷却器为实验研究对象,设计了结构参数、迎面风速、库温、驱动温差和供液倍率等多因素、多水平的实验方案,并采用校准箱法测得不同测点下的传热系数。采用测试数据并以关联式为目标函数,通过非线性拟合方法建立了适用于氨泵供液空气冷却器传热系数计算的关联式。关联式计算值与实测值相对误差在±10%之间,且分项管内换热系数大于管外换热系数,符合空气冷却器换热系数分布的一般规律,证明了传热关联式是合理准确的。在氨泵供液空气冷却器常用设计点,关联式计算值约为设计经验值1.11~1.30倍,这表明采用关联式设计该类型空气冷却器可节约11%~30%的换热面积,提高了经济效益。
A reasonable heat transfer coefficient correlation for a finned-tube air cooler was established by applying the methods of dimen- sional analysis and function analysis. This approach focused on an air cooler design in which the refrigerant phase changes in the tube. A pump-feeding ammonia air cooler was chosen as the experimental study object. Further, a multi-factor and multi-level experimental scheme was designed for this machine type. The scheme included the structure parameters, face velocity, ambient temperature, driving temperature, and circulation ratio. The heat transfer coefficients were tested under various conditions using a calibrated-box method ac- cording to the scheme. Moreover, the heat coefficient correlation of the pump-feeding ammonia air cooler was obtained through a nonlinear fitting method based on the test results. It was found that the relative errors between the calculated correlation values and the test values range from - 10% to ＋ 10%. Furthermore, the tube side heat coefficient is larger than the outside heat coefficient, which is consistent with practical experiments. These results show that the established correlation is reasonable and sufficiently accurate for use in practice. The calculated correlation values are 1.11 to 1.30 times the experimental values at the common design points for the pump-feeding ammonia air cooler. Thus, the heat transfer surface can be reduced by 11%-30% when the correlation is applied in the design of this type of air cooler. This correlation is helpful for reduction of the machine dimensions and to enhance its economic effieiency.
作者
赵泽波
石献金
于志强
于国昌
Zhao Zebo Shi Xianjin Yu Zhiqiang Yu Guochang(Research and Design Department, Yan Tai Moon Co. , Ltd. , Yantai, 264000, China China Productivity Center for Machinery, China Academy of Machinery Science ＆ Technology, Beijing, 100044, China)
出处
《制冷学报》
CAS
CSCD
北大核心
2017年第5期71-75,共5页
Journal of Refrigeration
关键词
空气冷却器
翅片管
传热关联式
校准箱法
air cooler
finned tube
heat transfer correlation
calibrated box method
