一、前言 自然循环热水锅炉具有水容大、突然停电时不易汽化及易将蒸汽炉改成热水炉等优点,所以在热水锅炉的新产品中及蒸汽炉改热水炉中占有重大比例。自然循环热水锅炉设计有对流排管,排管的吸热比相当大,通常可达锅炉总吸热量的30～40％,是锅炉上的一个主要部件。它设置在炉膛的烟气温度较高区域,若管内水速过小,可能出现过冷 I. Introduction Natural circulation of hot water boiler has a large water capacity, when a sudden power outage is not easy to vaporize and easy to steam boiler into a water heater and so on, so in the hot water boiler new products and steam oven hot water heater occupies a significant proportion. Natural circulation hot water boiler designed convection pipe, pipe heat absorption ratio is quite large, usually up to 30 ~ 40% of the boiler total heat absorption, is a boiler on a major component. It is set in the furnace flue gas temperature higher area, if the tube water speed is too small, may appear too cold