A Heat Recovery Steam Generator is an integrated, modular waste heat recovery device primarily used to recover waste heat from high-temperature flue gases emitted by industrial processes, gas turbines, and internal combustion engines, converting it into steam or hot water. This allows for cascaded energy utilization and improves overall system energy efficiency. Its modular design allows for easy installation, rapid commissioning, and strong adaptability, making it widely used in the chemical, power, metallurgical, and waste incineration industries.The heat recovery steam generator (HRSG) is a key component for efficient energy utilization. With increasing energy conservation and environmental protection requirements, modular HRSGs have become a key option for power plants, the chemical, metallurgical, and petrochemical industries. The modular design divides the boiler structure into transportable units, facilitating sea and land transportation and hoisting. It also requires a smaller site footprint, making it suitable for projects with limited space. The HRSG fully utilizes the high-temperature exhaust gas from the gas turbine, improving overall efficiency by approximately 20%-30% compared to a single gas cycle.

The economizer module is a core functional module used in thermal systems such as waste heat boilers and industrial boilers to recover low-temperature flue gas waste heat and preheat boiler feed water. Its main function is to absorb low-temperature heat from the flue gas (usually flue gas temperatures are between 200-400°C) to increase the feed water temperature entering the boiler evaporator, thereby reducing fuel consumption and improving the overall thermal efficiency of the boiler. By raising the feed water temperature, the economizer module reduces the heat required for fuel combustion, significantly lowering fuel consumption and operating costs, resulting in significant economic benefits. Raising the feed water temperature helps stabilize the boiler's steam pressure and temperature parameters, reducing operational fluctuations. While saving fuel, it also reduces carbon dioxide, nitrogen oxide, and dust emissions. This has positive implications for energy conservation and emission reduction efforts, helping enterprises achieve their "dual carbon" goals. Different economizer designs (smooth tube, pulverized coal, biomass, etc.) can be designed based on boiler type (HRSG, pulverized coal, biomass, etc.) and process requirements. They are adaptable and flexible to varying flue gas temperatures and water quality conditions.

Finned tubes, by expanding heat transfer area and reducing flue gas-side thermal resistance, have become a core component for enhancing heat transfer and reducing energy consumption on low-temperature heating surfaces of boilers (economizers and air preheaters). Their application requires careful consideration of the boiler's flue gas characteristics and working fluid parameters, with the appropriate fin type (spiral fin tubes, H-shaped fin tubes, etc.) and material selection. By optimizing geometric parameters, fluid flow rates, and strengthening operational maintenance, the goals of efficient heat transfer, low energy consumption, and long life can be achieved. As boilers evolve toward higher performance and lower emissions, upgraded finned tube materials (such as new corrosion-resistant alloys) and structural optimization (such as high-efficiency, low-resistance fins) will become key future developments.