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对于真空热水锅炉的换热管内水而言,需经历三个阶段来获得热量:1)管外侧水蒸汽与换热管外壁的凝结换热;2)换热管外壁与内壁导热;3)换热管内壁管内水的对流换热。在真空热水锅炉的设计中,第一阶段和第三阶段的传热系数计算经常凭经验进行估算,难以较好地控制材料用量与成本。本文主要研究了真空热水锅炉的换热管内水与管外侧水蒸汽换热过程进行分析计算,并计算分析了管径和管内水流速度对紫铜管和SUS304钢管总换热效果影响,可较好地指导真空热水锅炉的换热管设计。
For the water in the heat exchanger tube of the vacuum hot water boiler, three stages are required to obtain the heat: 1) condensation heat exchange between the water vapor outside the tube and the outer wall of the heat exchange tube; 2) heat conduction between the outer wall and the inner wall of the heat exchange tube; and 3) Heat exchange tube wall tube water convection heat transfer. In the design of a vacuum hot water boiler, the calculation of the heat transfer coefficients in the first and third stages is often estimated empirically, making it difficult to control the material usage and cost well. In this paper, the heat and water vapor exchange process inside and outside of the heat exchanger tubes in a vacuum hot water boiler was mainly studied. The effects of tube diameter and water flow velocity on the total heat exchange between copper tubes and SUS304 steel tubes were analyzed. Good to guide the vacuum hot water boiler heat transfer tube design.