船用增压锅炉的炉膛对流传热计算

由于增压锅炉燃烧压力的提高,强化了对流传热,如果仍按常压燃烧锅炉炉膛热力计算,忽略对流传热,将直接影响增压锅炉炉膛热力计算的准确性。文中对增压锅炉与常压燃烧锅炉炉膛特性参数进行了比较,对前苏联增压锅炉的试验数据进行了分析探讨,指出了增压锅炉炉膛对流传热的影响因素。同时提出增压锅炉炉膛传热计算应将辐射与对流传热分开计算,给出了适用于增压锅炉炉膛对流传热的计算公式,并进行了实例计算分析,与前苏联增压锅炉试验的计算数据结果相近。对于完善增压锅炉的炉膛热力计算具有一定的理论和实际指导意义。

Calculation of the Convection Heat Transfer in a Marine Supercharged Boiler Furnace

The furnace heat transfer calculation of normal pressure combustion boilers has long been mastered by boiler designers,in which the convection heat transfer can be virtually ignored.Due to an increase of combustion pressure in supercharged boilers,the convection heat transfer has been intensified and the neglect of convection heat transfer will directly influence the accuracy of the furnace thermodynamic calculation.The furnace characteristic parameters of supercharged boilers are compared with those of normal-pressure combustion ones along with an analysis of the supercharged boiler test data of the former Soviet Union.The influencing factors on furnace convection heat transfer in a supercharged boiler have been pinpointed.The author has proposed that the furnace heat transfer calculation of a supercharged boiler should be divided into a radiation and convection one.A calculation formula applicable for furnace convection heat transfer in a supercharged boiler was given and a specific case calculation and analysis has been conducted.The calculation results approximate to those obtained from the tests of the supercharged boiler of the former Soviet Union.The foregoing can provide a definite theoretical and practical guidance for improving the furnace thermodynamic calculation of supercharged boilers.