The construction of fossil fuel power plants usually includes planning, design, and water vapor cycle control.
Seamless steel pipes and
pipe fittings for high-pressure boilers of various sizes made of multiple materials are one of the key components for the normal operation of these power plants. No matter which part of the power plant, there will always be water or steam passing through. Just like the blood vessels of the human body, they can ensure the safe and reliable operation of power plants, thus providing significant help for energy supply.
Today's power plants achieve higher work efficiency by using higher working temperatures and working pressures. This is conducive to environmental protection, while helping to maintain the cost of energy inspections. In terms of technology, this means that in the production of seamless steel pipes and fittings for high-pressure boilers, the requirements for materials are increasing.
The operating temperature and bearing pressure of the high-pressure seamless piping system for thermal power plants under high temperature and high pressure conditions:
The high-pressure seamless pipeline system transmits steam under high temperature and high pressure conditions, or transmits water under moderate temperature and high pressure conditions.
The maximum steam pressure and temperature of the main steam high-pressure seamless pipeline are about 600 °C and 280 bar respectively; the steam in the superheater is used to deliver to the high-pressure steam turbine. The high-temperature reheat pipeline must also withstand high temperatures, but its pressure is lower than that of the main steam pipeline. The steam recovered from the high-pressure feedwater steam turbine is heated in the reheater and flows to the low- and medium-pressure steam turbine.
The
high-pressure seamless pipeline transports liquid water to the boiler vessel at a moderate temperature of 320°C and a high pressure of 370bar.
In order to adapt to the high-capacity and high-pressure steam flow, the main steam high-pressure seamless pipeline system needs large-diameter and thick-walled pipelines. Because the operating temperature is relatively low, the wall thickness of the high-temperature reheat pipe is usually smaller, but the outer diameter is larger. All these pipes must meet the requirements of a specific inner diameter so that they can match the actual steam flow.
Steam pipes are usually made of high-alloy ferritic steel with a chromium content of up to 12%. In addition, general pipelines can also be made of carbon steel or low-alloy ferritic steel into high-pressure seamless pipelines. At present, the maximum outer diameter of domestic high-pressure seamless pipelines can reach 1500 mm, and the maximum wall thickness can reach 270 mm.
