Low Temperature Reheater Coil Boiler Pressure Parts For Reheat Systems

Low-Temperature Reheater Coil for Industrial and Utility Boiler Reheat Systems with Optimized Gas Flow

The Low-Temperature Reheater Coil is a pressure-bearing heating surface component arranged in the low-temperature flue gas zone of industrial and utility boilers to reheat turbine exhaust steam, thereby improving overall cycle thermal efficiency. Engineered with precision and durability in mind, this reheater serves the primary function of preheating exhaust steam from the high-pressure turbine stage before it enters the high-temperature reheater, reducing moisture content in downstream turbine stages and extending equipment service life. As power generation and large industrial processes demand higher cycle efficiencies, the reheater system has become an indispensable element in modern reheat cycle boiler design, typically configured in boilers of sub-high pressure and above (>=5.3MPa).

The Low-Temperature Reheater Coil is specifically constructed to operate in the lower-temperature flue gas region where steam temperatures range from approximately 320C to 505C, depending on boiler pressure grade. The coil operates on the low-pressure steam side, with reheater inlet pressures typically ranging from 1.3MPa (sub-high pressure) to 3.8MPa (subcritical), significantly lower than superheater operating pressures. Material selection follows the temperature profile: 20G (SA-210) carbon steel for inlet sections below 460C, and 15CrMoG (SA-213 T12) alloy steel for outlet sections of 480-520C. Optimized coil pitch and tube spacing minimize gas-side pressure drop while ensuring effective convective heat transfer.

Manufactured using 20G / SA210 Gr.C carbon steel or 15CrMoG / SA-213 T12 alloy steel seamless boiler tubes with CNC bending and automatic circumferential welding, every Reheater Coil undergoes 100% NDT including UT, RT and PT, followed by hydraulic pressure testing to verify pressure integrity. Smooth internal tube surfaces ensure low steam-side pressure drop, while the serpentine arrangement provides sufficient heat transfer area within a compact boiler envelope. Post-weld heat treatment is applied to alloy steel sections to eliminate residual stress and ensure long-term creep resistance. Material certificates comply with ASME SA-210/SA-213 and GB 5310 standards.

One significant advantage of the Low-Temperature Reheater Coil is its contribution to improved Rankine cycle efficiency. By reheating steam between turbine stages, it reduces moisture content in the low-pressure turbine from approximately 12-15% (non-reheat) to below 10%, significantly extending turbine blade life and reducing erosion damage. The reheat cycle typically improves overall plant thermal efficiency by 3-5 percentage points compared with non-reheat cycles. The optimized coil design also contributes to stable reheat steam temperature control, which is critical for maintaining turbine efficiency and preventing thermal stress in downstream equipment.

The Low-Temperature Reheater Coil is adaptable to various boiler pressure grades and capacities, from sub-high pressure (6.4MPa, reheat inlet 1.3MPa) to subcritical (16.7MPa, reheat inlet 3.8MPa), making it suitable for power generation, large industrial steam and coking waste heat applications. Its versatility and robust construction enable it to perform reliably in both base-load and cycling boiler operation. Furthermore, the coil can be customized to meet specific process requirements, such as different steam pressures (1.3-3.8MPa), temperatures (320-505C) and tube configurations, ensuring optimal performance tailored to individual reheat system designs.

In addition to its functional benefits, the Low-Temperature Reheater Coil is designed with safety and operational convenience in mind. The materials and fabrication methods comply with ASME BPVC Section I and GB/T 16507 standards, ensuring safe operation under pressure-bearing conditions. Although reheater operating pressure is lower than superheater pressure, the large tube diameter and high steam flow require careful structural design to withstand flow-induced vibration. The modular coil design facilitates straightforward installation, inspection and replacement during boiler maintenance, with support structures designed to allow free thermal expansion.

To summarize, the Low-Temperature Reheater Coil represents an essential component in boiler reheat cycle systems. By delivering efficient preheating of turbine exhaust steam with low gas-side resistance, it improves cycle efficiency, extends turbine service life and reduces fuel consumption in medium and large capacity boilers. Its optimized design, systematic material selection and comprehensive quality control make it an ideal choice for boiler projects incorporating reheat cycles. Investing in high-quality reheater coils is a strategic decision that supports long-term energy efficiency, equipment reliability and compliance with evolving power generation standards.

Features

·        Optimized coil pitch minimizes flue gas resistance and pressure drop

·        Systematic material: 20G (SA-210) for <=460C, 15CrMoG (SA-213 T12) for 480-520C

·        Smooth internal surface ensures low steam-side pressure drop

·        CNC precision bending + automatic full-penetration circumferential welding

·        100% NDT (UT/RT/PT) + hydraulic test for pressure integrity

·        Reheater steam side pressure: 1.3MPa - 3.8MPa (typical, lower than superheater)

·        Steam temperature range: 320C - 505C depending on boiler grade

·        Post-weld heat treatment for alloy steel sections

·        Improves cycle efficiency by 3-5% vs non-reheat boiler design

·        Modular design for easy installation and replacement during maintenance

Technical Parameters

Applications

The Boyu Low-Temperature Reheater Coil is an essential heating surface component designed for boiler reheat cycles to improve thermal efficiency. Manufactured in Shandong, China, this reheater coil is available in customizable configurations to meet diverse boiler reheat system requirements. Certified with ISO9001, ASME, Grade A, SGS, the product guarantees high quality, safety and reliability in various power and industrial boiler applications.

This Reheater Coil is widely used in industrial reheat boilers, power station boiler low-temperature reheater sections, coking waste heat boilers with reheat cycles and large industrial boilers where improved cycle efficiency is desired. Its optimized design ensures low gas-side resistance and uniform heat transfer, contributing to stable reheat steam temperature. The coil is suitable for both new boiler construction and reheat system retrofitting projects aimed at improving plant efficiency and reducing fuel consumption.