High Pressure Natural Circulation Steel Boiler Manifold Headers for Power Plant

Product Introduction

• Air preheater is a kind of preheating equipment to improve the heat exchange performance of boilers and reduce heat loss. The function of air preheater is to heat the flue gas discharged from the tail flue of the boiler and transmit it to the air before entering the boiler through the radiator to preheat the air to a certain temperature.
• It is mostly used in coal-fired utility boilers. It can be divided into tube box type and rotary type. The rotary type can be divided into wind hood rotary type and heating surface rotary type. The rotary preheater with heating surface is often used in power plant boilers. Generally, the application in boilers is two-compartment, three-compartment and four-compartment, among which the four-compartment is more commonly used in circulating fluidized bed boile

Functions

1. Improve and intensify combustion
The air after the heat exchanger enters the furnace, which accelerates the drying, ignition and combustion process of the fuel, ensures the stable combustion in the boiler and improves the combustion efficiency.

2. Enhance Heat Transfer
Because the combustion in the furnace has been improved and strengthened, and the temperature of hot air entering the furnace has been increased, the average temperature level in the furnace has also been raised, so the radiation heat transfer in the furnace can be strengthened.

3. Reducing the loss in the furnace, lowering the exhaust gas temperature and improving the thermal efficiency of the boiler.
Because of the stable combustion in the furnace and the enhanced radiation heat exchange, the chemical incomplete combustion loss can be reduced. On the other hand, the air preheater uses the waste heat of flue gas to further reduce the loss of exhaust gas, thus improving the thermal efficiency of the boiler. According to experience, when the air in the preheater rises by 1.5 C, the exhaust gas temperature can be reduced by 1 C. After installing the air preheater in the boiler flue, if the air waste heat can be 150-160 C, the exhaust gas temperature can be reduced by 110-120 C, and the thermal efficiency of the boiler can be increased by 7%-7.5%. Fuel can be saved by 11%-12%.

4. Hot air can be used as fuel desiccant.
Hot air is an important desiccant and pulverized coal conveying medium for grease powder system in power plant boilers.

Features

• The pressures and temperatures that headers have to withstand depend on the component to which they are connected. A header connected to an economizer or to water wall panels is subject to less severe requirements on the material than a header connected to superheaters or reheaters.
• Depending on the temperature and pressure of headers, Vallourec supplies tubes in carbon steel to high-alloy ferritic steels such as T/P91 or T/P92, with sizes ranging from 88.9 mm to 406.4 mm.

Details

• 1.The necking hinders of the Company are made by hot press and retracting of seamless steel pipes at special hinder necking machine.
• 2.In this way, the hinders will have thicker walls and cleaner surface. The necking cover will form membrane stress rather than bending stress with desired stress performance under the effect of inner pressure.

Parameters

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