Advanced Superheater And Reheater Components For High Temperature Steam Generation

High Temperature Steam Superheater And Reheater in thermal power plant

Superheater & Reheater Components

Superheater mainly has heating tubes of heat - resistant alloys in flue gas path. Reheater has heating tubes in convective pass, plus inlets, outlets and supports.

Product Description

To improve the thermal efficiency, the pressure of superheated steam have been increased from superhigh pressure to subcritical and supercritical pressure. But limited by the metal performance, the steam temperature of superheaters and reheates are kept within 540-555 degrees.

Because what flow through tubes of superheaters and reheaters are high temperature steam, the convective heat release transfer coefficient of tube wall to steam is quite small, and heat transfer performance is poor, the cooling capacity of steam to tube wall is low. Meanwhile, to make sure reasonable temperature difference of heat transfer, usually superheaters and reheaters are placed at the areas where smoke temperatures are high, and their working temperature of tube wall is rather high, thus the working environment of superhearters and reheaters are quite bad. Especially reheaters, for reheated steam pressure is low, and their capacity to cool tubes are worse, thus that how to make sure tube metal can be safe working on the long term is an important issue when comes to design and operation of superheaters and reheaters. Diagram 4-1 lists the upper limit of allowable temperatures for common metal used in boilers. To avoid use of higher level of alloy steel, when it comes to design of superheaters and reheaters, used tube metal are almost close to the temperature limits when working. This time, if there is rise of temperature of 10-20 degrees, which also reduces the allowable stress a lot. Therefore, Attention should be paid for the design and running of superheaters and reheaters in aspects below:

1.to make sure the steam temperature stable when running. The variation of steam temperature is supposed to be not over+5- -10 degrees;

2.There needs reliable method to adjust temperatures for superheaters and reheaters when operation conditions changes to some extend to maintain rated steam temperatures.

3. to minimize the thermal deviation between parallel tubes.

Superheater is to increase the temperature of the steam above its saturation point.
Reheater is basically a superheater that superheats steam exiting the high-pressure stage of a turbine. The reheated steam is then sent to the low-pressure stage of the turbine. By reheating steam between high-pressure and low-pressure turbine it is possible to increase the electrical efficiency of the power plant cycle beyond 40%.The reheat cycle is used in large power boilers since it is feasible economically only in larger power plants.

Details

All the raw materials will be firstly made pipeline cutting.

It is consisted of a series of bare oil(carbon steel,alloy steel,or durable heat steel) and header and other auxiliaries. TubesΦ32,38,42 and so on,also as the request.

Differences

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

Company Introduction

Established in 1985,Zhangjiagang Hua Dong Boiler Co.,Ltd.(trading as HD Boiler),produces power plant; industrial; waste heat; waste incineration; biomass; organic heat carrier and electric steam boilers. Coupled with a comprehensive range of heating surfaces, HD Boiler brings to the market a unique service including boiler design , fabrication, installation, maintenance and replacement of boiler pressure parts.

1. Fabrication area of 200,000 square meters
2. 150 Engineers
3. 600 Coded welders
4. 60 Licensed Inspectors(NDT Level-III instructors)
5. Class-A Licenses for Design and Manufacture Boiler
6. ISO 9001:2008 Quality System
7. ASME Certificate of Power Boilers
8. ASME 'S','U' and NB stamp authorization