Metal Consumption Reduction Superheater And Reheater For Industrial Boilers

Description

The function of Super heater in the thermal power plant is to remove the last traces of moisture from the saturated steam coming out of boiler and to increase its temperature above saturation temperature as per requirement at inlet of steam turbine.

Details

• Superheating raises overall efficiency as well as avoids too much condensation in last stages of turbine which avoids blade erosion.

• The heat of combustion gases from furnace is utilised for removal of moisture from steam and to superheat the steam.

• Super-heaters ususlly have several tube circuits in parallel with one or more return bends,connected between headers.

• Heat from the hot gases to the vapour in the surperheater is transferred at high temperatures.

• Therefore promary section of superheater is arranged in counterflow and secondary section in parallel flow to reduce the temp.stressing of the tube wall.

Functions and characteristics of superheaters and reheaters

functions of superheaters and reheaters:

Superheaters and reheaters are important parts for the heating surfaces, used to increase steam temperature, aiming to improve steam enthalpy and further to increase the thermal circulation efficiency for power station.

Superheaters work to heat surnatured steam to superheated steam with a certain tempetature. When boiler loads or other working conditions change, it is necessary to make sure superheated steam temperature to be normal, and within allowable range of temperature variation.

From the thermal circulation in power station, the original parameters of pressure and temperature is higher, the thermal efficiency of circulation is better, or the steam humidity of the steam turbine rear is too high, influencing its safety. While the superheaer steam temperature is limited by metal materials, at present, due to limitation of metal materials, superheated temperature for most power station boilers are still within the range of 540-555 dgrees, and to avoid the steam humidity of blade of steam turbine rear too big, thus middle reheating system is applied.

Functions of reheaters are to heat exhaust of steam turbine high pressure cylinder to the reheated temperature which is close or equal to superheated temperature, and then send them to middle pressure cylinder and low pressure to expand and work to increase the dryness of blace of steam turbine rear. Usually, the pressure of reheated steam is one fifth of that of superheated steam. Application of reheating system can increase the thermal efficiency for power stations by 4-5%.

Principle

• Principle of superheater is similar to steam generating tubes of boiler.

• The hot gases at high temperature sweep over superheater tubes and raise the temperature of steam which magnitude depends upon exit gas temperature leaving the superheater and gas velocity.

Application

use for heating saturated steam, steam temperature could be up to 900 degree C.

Superheater Capacity Upgrades to Increase Power Generation

Send us required technical data, such as steam capacity, presure, required temperature etc. We will design accordingly.

Differences