Article

The construction and operation of coal-fired power plants necessitate a careful selection of metal pipelines tailored to specific operational environments and functional requirements. This article outlines the critical materials employed across various systems within these facilities.

**Boiler System Pipelines** utilize chromium-molybdenum alloy steel (e.g., ASTM A335 P11/P22/P91/P92) and austenitic stainless steel (e.g., TP304H, TP347H) for high-temperature, high-pressure applications in boiler furnaces and superheaters, capable of enduring steam temperatures exceeding 600áC.

**Main Steam and Reheat Steam Pipelines** predominantly feature martensitic heat-resistant steel (P91/P92, T91/T92) and nickel-based alloys (e.g., Inconel 617), designed to transport steam at temperatures up to 625áC and pressures of 30MPa, ensuring superior creep resistance.

**Condensate and Feedwater Systems** employ low-carbon steel (ASTM A106 Gr.B) and austenitic stainless steel (304/316L) for low-temperature water transport, with protective coatings to enhance corrosion resistance in sensitive applications.

**Flue Gas Treatment Systems** utilize duplex stainless steel (2205, 2507) and nickel-based alloys (C-276), critical for handling corrosive environments in wet flue gas desulfurization processes.

**Fuel Transport Pipelines** require wear-resistant materials like high-chromium cast iron (Cr26) and ceramic-lined options to withstand abrasive coal particles, particularly at bends.

**Cooling Water Systems** leverage copper-nickel alloys and galvanized steel, focusing on resistance to seawater and freshwater corrosion, while **Auxiliary Systems** utilize carbon steel and stainless steel for compressed air and ammonia injection systems.

Material selection is driven by factors such as temperature, pressure, corrosive media, and cost-effectiveness, with advancements in ultra-supercritical technology hinting at the future use of new heat-resistant alloys like G115 steel to enhance operational efficiency.

In conclusion, strategic material selection is crucial for the longevity and performance of coal-fired power plants, balancing cost and maintenance with the need for high operational standards in various extreme conditions.