Heat Efficiency Improving Boiler Parts Superheater Coils ASME
Standard For Power Station
Product Introduce:
Superheater
Fossil fuel power plants often have a superheater section in the
steam generating furnace.The steam passes through drying equipment
inside the steam drum on to the superheater, a set of tubes in the
furnace. Here the steam picks up more energy from hot flue gases
outside the tubing, and its temperature is now superheated above
the saturation temperature.
Reheater
Power plant furnaces may have a reheater section containing tubes
heated by hot flue gases outside the tubes. Exhaust steam from the
high-pressure turbine is passed through these heated tubes to
collect more energy before driving the intermediate and then
low-pressure turbines.
| 1 | Material composition | Carbon steel, alloy steel or heat-resistant steel, collection boxes
and other supporting material. Tubes are customized types of
specifications. |
| 2 | Design pattern | Vertical or horizontal layout. |
| 3 | Advantages | Beautiful appearance, size, accuracy, first-class bending and
welding technology, first-class detection equipment. |
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.
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.
Design structure
1. heating saturated steam, temperature up to 900 degree C.
2. high efficiency, >90%.
3. high speed heating.
4. design with stainless steel.
5. long design service life, 15 years.
Functions:
Superheater
1.Superheater is a device for heating saturated steam into
superheated steam at a certain temperature.
2. After the saturated steam is heated into superheated steam, the
work capacity of steam in the steam turbine is improved, that is,
the useful enthalpy of steam in the steam turbine is increased,
thus improving the cycle efficiency of the heat engine.
3. In addition, the adoption of hot steam can also reduce steam
exhaust humidity of steam turbine, avoid corrosion of steam turbine
blade, and create favorable conditions for further reduction of
steam exhaust pressure and safe operation of steam turbine.
Reheater
In order to improve the heat efficiency of large generating sets,
intermediate reheat cycle is widely used.The main steam coming out
of the boiler superheater is sent to the reheater to increase the
temperature after the work is done in the high pressure cylinder of
the steam turbine. Then it is sent to the middle pressure cylinder
of the steam turbine to continue expansion and work.Some large
units, after the middle pressure cylinder will exhaust steam back
to the boiler heating, known as two intermediate reheat cycle, can
be relatively improved circulation efficiency of about 2%.Some test
units even adopt three reheat cycles.After the reheat cycle is
adopted, the thermal system, structure and operation adjustment of
the boiler and steam turbine device become complex and the cost
increases, so it is adopted in the generating units of more than
100 megawatts, usually only once intermediate reheat is used.
Advantages of reheater are as follows:
1. Reduce the humidity of water vapor, which is conducive to the
protection of turbine blades.
2. The relative and absolute internal efficiency of steam turbine
can be improved.
HD Boiler offers a best in class facility,including
- Fabrication area of 200,000 square meters
- 150 Engineers
- 600 Coded welders
- 60 Licensed Inspectors (including NDT level-lll instructors)
- Grade-ALicenses for Design and Manufacture boiler (issued by the State
Administration of Quality Supervision and Inspection)
- ISO 90001:2008 Quality System
- ASME Certificate of Utility Boiler
- ASME‘S’ , ‘U’ and NB stamp authorization
