Boiler steam superheater

Steam superheater function

Steam superheater is a vital heating surface of boiler system to improve circle efficiency in thermal power plant. It receives energy from flue gas and heats wet steam (saturated steam) from steam bag into dry steam (superheated steam), which is sent to turbine. During this conversion, more thermal energy is stored in dry steam, which is less likely to condensate in turbine.

To obtain higher thermal efficiency of power plant, superheated steam pressure is improved from ultra-high to subcritical and supercritical. But steam temperature is limited by heat resistance of superheater metal material. Usually, steam temperature is limited within 540-550℃. If superheater is made of better material, temperature could 560-660℃. Nowadays, 540℃ is still popular choice due to high price of heat-resistant metal material.

Types of  steam superheater

According to the location, superheater could be classified into radiant superheater in combustion furnace and convection superheater in flue gas duct.

Radiant superheater is usually located at the top of furnace. It receives majority of heat by direct radiation. As boiler capacity grows, the proportion of heat absorption by superheating goes up, while heat absorption by evaporation goes down. To have enough heating surface inside furnace and good steam temperature characteristic, single loop platen superheater is used to receive radiant heat from furnace and convective heat from flue gas. Platen superheater consists of many paralle tubes that form a wall-like or screen-like appearance.

Benefits of radiant superheater:

1. Increase radiant heat absorption. Reduce temperature of flue gas at furnace exit to avoid slagging.
2. Improve steam temperature characteristics. When boiler load changes, steam temperature change is more stable.
3. Damping and guiding for flue gas leaving furnace to eliminate residual swirl effects, resulting a better distribution of flue gas.
4. Less metal consumption due to arrangement in high temperature radiation zone.

Convection superheater is usually located at the flue gas duct. It receives majority of heat by convection. Convection superheater is usually multiple loop pendant superheater with vertical or horizontal arrangement.

Benefits of convection superheater:

1. Easy hanging up.
2. Less soot deposit.

Steam superheater manufacturing

GeckoInTech is reliable supplier for boiler heating surface like superheater, evaporator, economizer, air preheater. We provide OEM service for the maintenance and replacement of boiler parts.