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Middle/High Temperature Stainless Steel Superheater/Reheater Coil Tube Boiler Spare Parts
Functions and characteristics
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%.
Differences
Type | Advantages | Disadvantages | Supporting method |
Pendant-type | 1.Firm structural support | 1. Flow blockage by condensed steam 2. Needs slow restart to purge the water that accumulates in the bottom. | supported from above |
Inverted-type | 1.Proper drainage of the condensed steam | 1. Lack the structural rigidity, especially in high speed gas flow | Supported from below |
Horizontal -type | 1. Proper drainage 2. Good structural rigidity. | 1. They do not view the flam directly so they are mainly from the convective type | Usually supported in the vertical gas ducts parallel to the main furnace. |