Transcript

Energy-Efficient Steam Boiler Systems in the WorldAir, water and steam are three media commonly used to distribute heat to process loads.However, steam has several advantages compared to hot air and hot water. These advantagesinclude. the heat carrying capacity of steam is much greater than air or water steam provides its own locomotive force. steam provides heat at a constant temperaturePrinciples of Energy-Efficient Steam SystemsEnergy Balance ApproachThe figure below shows the primary energy flows into and out of a steam system.Basic steam systemSteam System ComponentsBoilers and Steam GeneratorsSteam boilers are broadly classified as fire-tube or water-tube boilers. In fire tube boilers,the boiler shell contains the water/steam and hot combustion gasses pass through the tubes to heatthe water/steam. In water-tube boilers, the water/steam passes through tubes and the hotcombustion gasses pass through shell of the boiler. The two types of boiler can be used in differentsituations to meet the industry needs for a higher efficiency.Fire-tube boilers are popular for smaller applications requiring saturated steam at less than 150psig because of their low first cost and durability. The large volume of water/steam serves asthermal mass which enhances steady operation. However, because the steam is generated on theshell side, the shell itself is a pressure vessel, making it difficult to generate steam at highpressures. In addition, the large surface area causes relatively large heat loss, which varies fromabout 0.5% of input energy at full-fire to a much higher fraction at low loads.Difference between fire tube and water tube boilerSteam generators are like water-tube boilers, except that they are made from light- weightmaterials. In many jurisdictions, the lack of a dedicated pressure vessel enables steam generatorsto be used without a boiler operator. The light weight materials and absence of a large holdingtank allow steam generators to come up to pressure quickly in a manner of minutes. This enablessteam-generators to be turned on and off as needed, reducing standby losses. Installing thewater-tubes in a counter-flow configuration to the path of the combustion gasses increases thermalefficiency.Steam boiler can be used for power generation, textile industry, food processing, sterilization andso on. ZG boiler has developed horizontal steam boiler use oil, gas, coal, biomass and waster heatas energy to provide various steam for the world industry.


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