HRSG SYSTEMS AND THE CRITICAL ROLE OF INSULATION IN HRSG SYSTEMS

Amid rising energy demands, the Combined Cycle Power Plant (CCPP) has emerged as an optimal solution, offering high efficiency and low environmental impact. At the heart of this system is the Heat Recovery Steam Generator (HRSG), which recovers exhaust heat to generate steam. However, proper insulation is essential to ensure the stable and durable operation of the HRSG system. This article outlines the importance of thermal insulation for HRSG systems and introduces services provided by Black Cat Insulation Technical JSC (Stock Code: BMK) for such applications.

HRSG System – Heat Recovery Steam Generator

The HRSG is a heat exchanger that utilizes exhaust heat from the gas turbine to produce steam. This steam then drives a steam turbine to generate electricity, thereby optimizing efficiency without consuming additional fuel.

Classification of HRSG Systems

Based on the number of steam pressure levels generated, HRSGs are categorized into two main types:

• Single-pressure HRSG: Produces steam at only one pressure level. This type features a simple design and lower initial investment costs, but generally offers lower heat recovery efficiency.
• Multi-pressure HRSG: Produces steam at multiple pressure levels (low, medium, and high). This design optimizes heat recovery from exhaust gases, significantly improving the overall system efficiency.

Based on exhaust gas flow configuration:

• Horizontal HRSG: The exhaust gas flows horizontally, with heat exchangers arranged vertically.
• Vertical HRSG: The exhaust gas flows vertically from bottom to top. This configuration is commonly used when horizontal space is limited.

Industries Utilizing HRSG Systems:

• Oil Refining and Petrochemical Plants: HRSGs are integrated with gas turbines to capture waste heat from combustion processes, producing steam for petrochemical processes or to drive steam turbines.
• Chemical Plants: Use HRSGs to recycle thermal energy from industrial processes, supplying steam for production operations.
• Cement and Steel Plants: Exhaust gases from kilns or furnaces are recovered through HRSG systems to generate steam, optimizing energy utilization.
• LNG (Liquefied Natural Gas) Power Plants: A specialized type of combined cycle power plant where liquefied natural gas is used as the primary fuel for gas turbines and HRSG systems.

Fundamental Components of an HRSG System

1. Heat Exchanger Tubes: Hot exhaust gases pass through the tubes and transfer heat to the water, converting it into steam.
2. Main Heat Exchange Zones:

Economizer Zone: Preheats the water before it enters the evaporator, utilizing the lower temperature portion of the exhaust gas.

Evaporator Zone: Converts water into saturated steam.

Superheater Zone: Increases the temperature of the steam to reach dry or superheated steam conditions, suitable for steam turbines.

3. Water and Steam Piping System: Delivers water, saturated steam, and superheated steam to the consuming equipment

4. Control Valves and Safety Devices: Pressure relief valves, temperature sensors, and pressure sensors to ensure safe operation.

5. Silencer and Stack: Discharges treated exhaust gas and reduces noise.

Plants utilizing HRSG systems not only optimize energy efficiency but also reduce CO₂ emissions to the environment, aligning with sustainability standards and development goals.

Why Insulation Installation Is Essential for HRSG Systems: The Role of Insulation

HRSG systems operate under extremely high temperatures—up to 650°C—requiring strict insulation practices to optimize performance and protect equipment integrity. Below are the key roles of thermal insulation in HRSG systems:

1. Reducing Heat Loss

Insulation minimizes thermal losses from the HRSG to the surrounding environment, maintaining optimal temperatures within heat exchange components. This not only conserves fuel but also reduces the operational load on the system.

2. Protecting Equipment

Thermal expansion and corrosion due to high temperatures pose serious risks to HRSG components. Insulation acts as a “shield,” protecting metal surfaces from thermal stress and extending the lifespan of the system.

3. Ensuring Operator Safety

Surface temperatures of HRSG components can pose hazards to personnel. Proper insulation lowers surface temperatures to safe levels, ensuring a safer working environment.

4. Enhancing Efficiency

Effective insulation ensures that thermal energy is directed precisely where it’s needed during heat exchange processes, thereby improving efficiency and reducing operating costs.

5. Environmental Protection

Improved thermal efficiency reduces the need for burning fossil fuels, which in turn lowers emissions. As a result, insulation supports sustainable development goals and minimizes environmental impact.

Insulation Materials for HRSG Systems

Modern insulation materials have been developed to meet the demanding requirements of systems like HRSG. Some common options include:

• Stone Wool (Mineral Wool): This is one of the most widely used high-temperature insulation materials today. It can withstand temperatures up to 650°C and is commonly applied to heat exchange components.

• Bông gốm Ceramic Fiber: Capable of withstanding extremely high temperatures (up to 1200°C), this material is typically used in high-heat areas such as the superheater section.

Selecting the right insulation material and designing an appropriate insulation system are critical factors in ensuring the long-term performance of an HRSG system

Insulation Product Supply and Installation Services by Black Cat JSC

With over a decade of experience in the insulation industry, Black Cat JSC delivers comprehensive and professional solutions—from material supply to complete installation.

Here are some images from key projects where Black Cat JSC has provided insulation for piping systems and heat recovery components within HRSG systems:

The HRSG system is the heart of combined cycle power plants, and thermal insulation serves as its protective “armor.” With extensive experience and expertise accumulated through numerous projects, Black Cat JSC is committed to delivering comprehensive insulation solutions that enhance operational efficiency and minimize risk.

Source: insulationmarket.com.vn