Heat Exchanger Coal Boiler Reheater Heat High Quality Boiler Superheater Boiler Parts metal tubes
Heat Exchanger Coal Boiler Reheater Type & Characteristics
1. The diameter of the tube is generally 30-60 mm. It has a relatively dense pipe group, which is arranged in flue gas temperature 450 - 1000 C, and is scoured horizontally and vertically by flue gas.
2. The flue gas mainly convects heat to the pipe, and some radiation absorbs heat. The former absorbs the radiation heat of the furnace flame, while the latter absorbs part of the convective heat.
3. In power plant boilers above 10 MPa, both screen and serpentine tube superheaters are usually used to increase heat absorption.
4. The wall superheater applied on the inner wall of the furnace is radiation superheater, which is seldom used. The wall-enclosed superheater is used to form the top of the furnace and the wall of the convective flue duct in a large-capacity power plant boiler.
5. The light furnace wall is made of insulating material. The picture shows the arrangement of several superheaters. Small capacity industrial boilers equipped with superheaters usually use convective superheaters of single-stage tubes to meet the requirements.
1. The reheater layout follows the superheater layout, including convection, radiation and semi-radiation.
2. The convection reheater has reverse flow, downstream flow and mixed flow, single coil, double coil, multi-coil, parallel and staggered, vertical and horizontal type, parallel to the front wall and perpendicular to the front wall.Convection reheater is the main reheater that absorbs convection heat.
3. Radiant reheater refers to the reheater absorbing furnace radiation.
4. Semi-radiant reheaters (plate superheater) refer to reheaters that absorb more radiation from the furnace (more than 1/2 of the total heat).
5. The material selection principle of reheater is the same as that of superheater. Since reheating steam is inferior to superheater in cooling capacity, the design wall temperature is generally higher than that of superheater of the same temperature level.Metal tubes of high temperature reheaters are generally made of alloy steel (metal tubes containing more than 5% of alloy elements).For example, 12CrlMoV, steel 102, sa213-t91, sa213-tp304, sa213-tp347, etc.
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
1.Proper drainage of the condensed steam
1. Lack the structural rigidity, especially in high speed gas flow
Supported from below
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.