青海华信锅炉有限公司|青海燃煤锅炉|青海燃气锅炉|青海锅炉公司|青海哪个品牌锅炉好
   水洉的形成是因为水里面溶解了矿物质，水垢有两种组成形式：一种是钙簇的碳酸盐、盐、硅酸盐以及氧化铁等组成的混合物，难以分出哪一种是主要成分，另一种是各种水垢以夹层的形式组成为一体，所以也很难指出哪一种成分是主要的。
水垢的导热性一般都很差。不同的水垢因其化学组成不同，内部孔隙不同，水垢内各层次结构不同原因，导热性也各不相同。假设有0.1mm厚的水垢附着在金属壁上，其热阻相当于加厚了几毫米到几十毫米。水垢的导热系数很低是水垢危害大的主要原因。
水垢的危害可归纳如下：
  1.浪费燃料、降低锅炉热效率
    因为水垢的导热系数比钢材的导热系数小数十倍到数百倍。因此锅炉结有水垢时，使锅炉受热面的传热性能变差，燃料燃烧所放出的热量不能有效地传递到锅炉水中，大量的热量被烟气带走，造成排烟温度升高，排烟热损失增加，锅炉的热效率降低。在这种情况下，为保证锅炉的参数，就必须更多投加燃料，提高炉膛的温度和烟气温度，因此造成燃料浪费。有人估算，锅炉受热面上结有1mm厚的水垢，浪费燃料约3%-5%。
  2.影响锅炉安全运行
    锅炉水垢常常生成在热负荷很高的锅炉受热面上。因水垢导热性能很差，导致金属管壁局部温度大大升高。当温度超过了金属所能承受的允许温度时，金属因过热而蠕变，强度降低，在锅炉工作压力下，金属会发生鼓包、穿孔和破裂、影响锅炉安全运行。

   Water dirt effectually formation because of dissolved minerals in the water, scale is composed of two forms: one kind is clusters of calcium carbonate, sulfate, silicate, and the mixture of ferric oxide, etc, it is difficult to tell which one is the main component, the other is a variety of scale in the form of intercalation composition as a whole, so it is hard to say which one component is the main.
    The thermal conductivity of the scale is generally very poor. Different scale because of its chemical composition is different, the internal pore space is different, different scale within the hierarchical structure, thermal conductivity are different. Assumptions are attached to the m e t al wall is 0.1 mm thick of scale, its heat resistance is equivalent to upset a few mm to tens of mm. Scale of low coefficient of thermal conductivity is the main reason for the large scale hazards.
The harm of scale can be summarized as follows:
   1. The waste of fuel, to reduce the boiler thermal efficiency
Because of the scale coefficient of thermal conductivity is dozens of times less than the coefficient of thermal conductivity of steel to hundreds of times. Therefore, boiler scale, make the heat transfer performance of boiler heating surface is poor, fuel combustion heat energy that is released by cannot be effectively passed to the boiler water, a lot of heat carried by flue gas, exhaust temperature, smoke heat loss increased, the boiler thermal efficiency is reduced. In this case, in order to ensure the boiler parameters, the fuel must be more investment, raise the temperature of the furnace and flue gas temperature, thus causing waste fuel. Some estimate, the boiler heating surface is 1 mm thick on the scale, the waste of fuel about 3% - 5%.
    2. Affect the safe operation of the boiler
Boiler scale are often generated at high heat load on the boiler heating surface. m e t al pipe wall caused by scale thermal conductive performance is very poor, the local temperature rise greatly. When the temperature exceeded the m e t al to withstand temperature, without the permission of the m e t al in overheating and creep strength is reduced, working in the boiler pressure, the m e t al will happen bulge, perforation and fracture, influence the safe operation of the boiler.
青海华信锅炉有限公司|青海燃煤锅炉|青海燃气锅炉|青海锅炉公司|青海哪个品牌锅炉好
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