In the ever-evolving landscape of industrial operations, efficiency and sustainability have become paramount. Companies are constantly seeking ways to optimize their processes, reduce costs, and minimize their environmental footprint. One often overlooked yet highly effective solution is the implementation of waste heat recovery systems, particularly waste heat boilers. In this blog post, we will delve into the world of waste heat boilers, exploring their capabilities, benefits, and real-world applications. We will also highlight how Gelan, a leading manufacturer of waste heat boilers, is revolutionizing the industry with its innovative and tailor-made solutions.
Understanding Waste Heat Recovery
Before we dive into the specifics of waste heat boilers, let’s first understand the concept of waste heat recovery. Industrial processes, such as those in refineries, power plants, and steel mills, generate a significant amount of heat as a byproduct. Traditionally, this heat is simply exhausted into the atmosphere, representing a substantial loss of energy and potential revenue. Waste heat recovery systems are designed to capture this otherwise wasted energy and convert it into useful forms, such as steam or hot water, which can then be utilized within the facility.
The principle behind waste heat boilers is relatively straightforward. These boilers are engineered to capture the heat from flue gases or other industrial processes and use it to heat water, thereby generating steam. This steam can then be employed for various purposes, including driving turbines to produce electricity, heating other process streams, or providing hot water for industrial use. By effectively harnessing this waste heat, companies can significantly reduce their reliance on external energy sources, lower fuel costs, and enhance overall operational efficiency.
The Role of Waste Heat Boilers
Waste heat boilers play a crucial role in maximizing energy recovery in industrial applications. They are specifically designed to address three major challenges commonly encountered in waste heat recovery systems: flue gas dew point corrosion, dust abrasion, and high-temperature performance. Gelan’s waste heat boilers, for instance, are engineered with advanced materials and technologies to ensure long lifespans, low resistance, and compact structures. This allows them to operate reliably across a wide range of flue gas temperatures, making them suitable for various industrial settings, including refinery heating furnaces, power plant boilers, and blast furnaces in steel mills.
One of the key benefits of waste heat boilers is their ability to generate steam efficiently. Gelan’s high-pressure waste heat boilers, for example, are capable of producing steam at pressures ranging from 1 to 6.5 Mpa, with steam generation capacities of up to 10 tons per hour. This high-pressure steam can be used to drive turbines, generating electricity that can be fed back into the facility’s power grid or sold to the local utility. In this way, waste heat boilers not only save energy but also create a new revenue stream for companies.
Types of Waste Heat Boilers
Gelan offers a variety of waste heat boiler types, each designed to meet specific industrial needs and maximize return on investment. Let’s explore some of the most common types and their applications:
Shell and Tube Waste Heat Boilers
Shell and tube waste heat boilers are one of the most widely used types due to their economical and efficient heat transfer capabilities. These boilers consist of a tube bundle or coil heat exchanger, with process media circulating inside the heat exchange tubes and cooling water filling the shell. The heat from the process media heats and boils the cooling water, producing steam.
There are two main subgroups of shell and tube waste heat boilers:
- With Steam Drum: These boilers have a steam drum connected to the boiler through riser and downcomer pipes, ensuring a continuous supply of steam.
- Without Steam Drum: These boilers have their own evaporation space, and U-tubes are typically used in the heat exchange tubes.
The benefits of shell and tube waste heat boilers include their suitability for cooling process media, generating steam for facility use, and handling high-temperature gases from industrial processes. They are ideal for applications where efficient heat transfer and steam generation are essential.
Flue Gas Waste Heat Boilers
Flue gas waste heat boilers are modular steam generators that utilize high-temperature flue gases to heat water and produce steam. These boilers are commonly used in chemical furnaces and feature vertically arranged heat exchange tubes. The heat from the flue gases is transferred to the water inside the tubes, generating steam that can be used for various industrial applications.
The advantages of flue gas waste heat boilers include efficient heat recovery from flue gases, steam generation for power production or subsequent processes, and the ability to handle high-temperature applications, such as hydrogen production and sulfur recovery units.
Other Types of Waste Heat Boilers
In addition to shell and tube and flue gas waste heat boilers, Gelan also offers specialized waste heat boilers for specific industries and applications:
- Coking Waste Heat Boilers: These boilers are designed to recover waste heat from coking plants, where large amounts of coking waste gas at temperatures ranging from 550 to 900°C are produced. By burning coke oven gas inside or outside the waste heat boiler and mixing it with coking waste gas, high-temperature flue gas is generated for heat exchange, producing rated steam. This process is cost-effective, environmentally friendly, and has a small footprint.
- Hazardous Waste Incineration Boilers: In industries such as printing, dyeing, and chemicals, toxic and hazardous gases are often produced. These gases are typically incinerated using direct combustion furnaces (TO furnaces), regenerative combustion furnaces (RTO), or catalytic combustion furnaces (RCO). After incineration, the waste heat is recovered and cooled down to meet the temperature requirements for desulfurization and denitrification, achieving both environmental protection and energy savings.
- Carbon Rotary Waste Heat Boilers: These boilers are used in the carbon production process, where carbonaceous raw materials (such as anthracite coal or petroleum coke) are calcined at high temperatures under air-insulated conditions. The high-temperature flue gas generated during calcination can be reused as waste heat. Gelan offers different specifications of waste heat steam boilers or waste heat organic heat carrier furnaces based on the actual waste heat resources, resulting in energy and cost savings.
Benefits of Gelan Waste Heat Boilers
Investing in a Gelan waste heat boiler offers numerous financial and operational benefits to companies. Some of the key advantages include:
Enhanced Durability and Corrosion Resistance
Gelan’s waste heat boilers are equipped with anti-abrasion devices in the flue gas inlet section to protect the windward tube bundle. The low-temperature section tube bundles are made from proprietary composite alloy pipes combined with soft enamel structures, ensuring overall corrosion resistance and durability. This means that the boilers can withstand harsh operating conditions and have a lifespan that is 3-5 times longer than conventional waste heat boilers.
Compact and Modular Design
Gelan’s waste heat boilers feature a compact structure that occupies less land area and space, typically reducing the volume by about 20% compared to traditional waste heat boilers. The modular design allows for flexible application and adjustments to fit the size of the heating furnace, facilitating transportation and installation. This makes it easier for companies to integrate waste heat boilers into their existing facilities without significant modifications.
High Heat Transfer Performance
Gelan uses imported finned tube production lines with a high-frequency resistance welding fusion rate, resulting in a fin welding rate exceeding 98%. This leads to low thermal resistance and improved heat transfer performance. The heat transfer performance per unit length of Gelan’s finned tubes can be enhanced by about 10% compared to domestic alternatives. This means that the boilers can generate more steam with the same amount of heat input, increasing overall efficiency.
Cost-Effectiveness
Gelan’s waste heat boilers offer a high overall cost-performance ratio and significant energy savings. The tail section of the heating surface, equipped with the newly developed waste heat boiler, can enhance the overall thermal efficiency of the heating furnace by 6% to 20%. This translates to substantial energy savings and a short investment payback period, making waste heat boilers a financially attractive solution for companies looking to improve their energy efficiency.
Real-World Applications and Success Stories
Gelan has successfully implemented waste heat boilers in various industrial sectors, including petrochemicals, metallurgy, and hydrogen production. These projects highlight the significant benefits of waste heat boilers in improving energy efficiency, reducing emissions, and saving costs.
Hydrogen Production
One notable example is the Cyprus 12 Million Tons Per Year Refinery Hydrogen Production Unit Waste Heat Boiler, which includes a 70-meter steel chimney. This project demonstrates the effectiveness of waste heat boilers in recovering energy from industrial processes and using it to produce hydrogen, a valuable and environmentally friendly fuel.
Atmospheric Distillation Units
Another success story is the Philippines Refinery Phase II 10 million tons per year atmospheric distillation unit, atmospheric heating furnace, and vacuum heating furnace, all of which include waste heat recovery systems. These projects showcase how waste heat boilers can be integrated into large-scale industrial operations to improve energy efficiency and reduce environmental impact.
Catalytic Reforming Units
Gelan has also worked on projects such as the Indonesia Refinery 1.8 Mt/a Catalytic Reforming Unit and Waste Heat Boiler. This project highlights the ability of waste heat boilers to recover energy from catalytic reforming processes, which are crucial for the production of high-octane gasoline and other petrochemical products.
Conclusion
Waste heat boilers represent a powerful and innovative solution for companies looking to enhance their energy efficiency, reduce costs, and achieve sustainability goals.