水套加热炉热力计算方法比较

Method Comparison for Thermal Calculation of Water Jacket Heater

针对采用SY/T 0535—94《火筒式加热炉热力与阻力计算方法》进行水套加热炉校核计算时,出现的随过量空气系数增加排烟温度不变、火筒出口烟温降低的问题,运用通用的燃油、燃气锅炉热力计算方法,对加热炉进行了重新校核计算。结果表明,通用热力计算法的结果与实际相符,即随过量空气系数增加,排烟温度增加、火筒出口烟温基本不变。分析发现,SY/T 0535—94中热力计算方法未考虑烟气成分对火筒辐射传热的影响,并过分夸大烟管对流传热能力,因而导致大过量空气系数时计算结果偏离实际。建议尽快出台新的水套加热炉热力计算标准,标准中应考虑烟气成分和灰垢热阻对传热的影响。

As problems,the phenomenon that exit gas temperature almost retains unchanged and the flame tube exit gas temperature decreases with the increase of excess air coefficient are encountered during the original calculation of a heater design per to SY/T 0535—94 Thermal and Resistance Calculation Method about Fire Tube Type Heater.The calculation results is found not agreed with the field test results and the calculation is rechecked with the general thermal calculation method for boilers fired by oil or gas.Conformance results are obtained and a further analysis shows the method in SY/T 0535—94 ignores the effect of gas constituents on heat transfer and enlarges heat transfer ability of gas tube which results in the calculating results based on SY/T 0535—94 do not agree with the experimental results.A new standard that the influence of flue gas components and fly ash on heat transfer be take into account is suggested to publish.