What is the Difference between EGB And HRSG

What is the Difference between EGB And HRSG
Share This Post

Table of Contents

What is the Difference between EGB And HRSG ? The main difference between EGB And HRSG is the type of waste heat they utilize. An exhaust gas boiler uses the waste heat from combustion engines or boilers, while a heat recovery steam generator captures the waste heat from gas turbines.

In an exhaust gas boiler, the waste heat is used to produce steam, which can be used for various applications within a system. On the other hand, a heat recovery steam generator uses the waste heat to generate steam in a thermodynamic Rankine Cycle, which is then used for power generation.

Understanding Exhaust Gas Boiler

Definition of an Exhaust Gas Boiler

An exhaust gas boiler is a type of heat exchanger that utilizes the waste heat from the flue gas generated by the combustion of fuel in engines, turbines, or other industrial processes. It is designed to recover the heat from the exhaust gas and use it to generate steam or hot water for various heating and power applications.

Function and Purpose of an Exhaust Gas Boiler

The main function of an exhaust gas boiler is to extract as much heat as possible from the exhaust gas to increase the overall efficiency of the system. It serves several purposes, including:

  • Heat Recovery: By recovering the waste heat from the exhaust gas, an exhaust gas boiler helps in improving the thermal efficiency of the system, reducing fuel consumption, and lowering greenhouse gas emissions.
  • Steam Generation: The recovered heat is used to generate steam, which can be utilized for various industrial processes, heating systems, and power generation.
  • Hot Water Generation: In addition to steam, an exhaust gas boiler can also produce hot water for domestic or commercial use, providing a cost-effective heating solution.

Working Principle of an Exhaust Gas Boiler

The working principle of an exhaust gas boiler involves the transfer of heat from the hot flue gas to the water or steam flowing inside the boiler tubes. This heat transfer process occurs through a combination of conduction, convection, and radiation.

The exhaust gas, which contains high-temperature flue gases, passes through the boiler tubes. These tubes are immersed in the water or have water flowing inside them. As the hot exhaust gas comes into contact with the cooler walls of the boiler tubes, heat is transferred from the gas to the water or steam.

The heat transfer efficiency of an exhaust gas boiler depends on various factors such as the temperature and flow rate of the flue gas, the surface area of the boiler tubes, and the temperature and flow rate of the water or steam. The design and configuration of the boiler also play a crucial role in maximizing heat transfer efficiency.

Overall, an exhaust gas boiler is a crucial component in energy recovery systems, helping to reduce energy waste, increase system efficiency, and contribute to sustainable energy practices.

Understanding Heat Recovery Steam Generator

Definition of a Heat Recovery Steam Generator

A heat recovery steam generator (HRSG) is a device that recovers heat from the exhaust gas of a gas turbine or reciprocating engine to generate steam in a thermodynamic Rankine Cycle. It is a high-efficiency steam boiler that utilizes the hot gases from the turbine or engine to generate steam, which can be used for various purposes such as power generation.

Function and Purpose of a Heat Recovery Steam Generator

The primary function of a heat recovery steam generator is to recover the waste heat from the exhaust gas and convert it into useful energy in the form of steam. The purpose of this process is to improve the overall efficiency of the gas turbine or reciprocating engine, as well as to utilize the waste heat that would otherwise be lost.

The generated steam can be used for various applications, such as:

  • Power generation: The steam can be used to drive a steam turbine and generate additional electrical power.
  • Process heating: The steam can be used for industrial processes that require heat, such as in chemical plants or refineries.
  • District heating: The steam can be used to supply heat to residential or commercial buildings through a centralized heating system.
  • Desalination: The steam can be used to generate fresh water through a process called desalination, where saltwater is converted into potable water.

Working Principle of a Heat Recovery Steam Generator

The working principle of a heat recovery steam generator involves several key components:

  1. Exhaust gas inlet: The exhaust gas from the gas turbine or reciprocating engine enters the HRSG through an inlet.
  2. Heat transfer surfaces: The exhaust gas flows over heat transfer surfaces, such as tubes or plates, which are designed to extract heat from the gas and transfer it to the water or steam inside the HRSG.
  3. Water/steam circulation system: The HRSG has a water or steam circulation system that allows the water or steam to flow through the heat transfer surfaces and absorb the heat from the exhaust gas.
  4. Steam drum: The steam drum collects the generated steam and separates it from any remaining water or liquid.
  5. Steam turbine: The generated steam can be used to drive a steam turbine, which converts the thermal energy of the steam into mechanical energy.
  6. Condenser: The steam, after passing through the steam turbine, is condensed back into water in a condenser and then returned to the HRSG for further heat recovery.

The working principle of a heat recovery steam generator is based on the thermodynamic principles of heat transfer and energy conversion. By utilizing the waste heat from the exhaust gas, the HRSG maximizes the efficiency of the overall power generation system and reduces the environmental impact by minimizing the emissions.

What is the Difference between EGB And HRSG ?

When it comes to recovering waste heat from exhaust gases, two common solutions are exhaust gas boilers and heat recovery steam generators. While both serve the same purpose of utilizing waste heat to generate steam, there are some key differences between the two. In this article, we will explore these differences in terms of boiler design and construction, application and usage, and efficiency and energy conversion.

Boiler Design and Construction

An exhaust gas boiler is a type of water tube boiler that utilizes the energy from the exhaust gases of a combustion process to heat water and produce steam. It typically consists of several tubes through which the hot exhaust gases pass, transferring their heat to the surrounding water. The construction of an exhaust gas boiler is relatively simple, with the main focus on maximizing heat transfer efficiency.

In contrast, a heat recovery steam generator (HRSG) is a more complex system that is specifically designed to recover heat from the exhaust gases of gas turbines. It employs a combination of heat exchangers, pipes, and ducts to extract the maximum amount of heat from the exhaust gases and transfer it to the working fluid. The construction of an HRSG is more intricate and requires precise engineering to ensure optimal heat recovery.

Application and Usage

The application and usage of exhaust gas boilers and HRSGs also differ. Exhaust gas boilers are commonly used in marine applications, where they recover heat from the exhaust gases of ship engines and produce steam for various onboard processes. They are also found in industrial settings where there is a need for both steam and hot water.

On the other hand, HRSGs are primarily used in combined cycle power plants, where they recover heat from the exhaust gases of gas turbines and generate additional steam for power generation. They are also employed in cogeneration plants, where heat and electrical power are simultaneously produced. The application of HRSGs is mainly limited to power generation and large-scale industrial processes.

Efficiency and Energy Conversion

One of the main factors that differentiate exhaust gas boilers from HRSGs is their efficiency and energy conversion capabilities. Exhaust gas boilers typically have lower efficiency compared to HRSGs due to the limitations of their design and construction. They are less effective in extracting heat from the exhaust gases, resulting in lower energy conversion efficiency.

HRSGs, on the other hand, are specifically designed for maximum energy recovery. They employ advanced heat exchangers and precise controls to optimize heat transfer and energy conversion. As a result, HRSGs have higher overall efficiency and can achieve higher energy conversion rates compared to exhaust gas boilers.

In conclusion, the key differences between exhaust gas boilers and heat recovery steam generators lie in their boiler design and construction, application and usage, as well as efficiency and energy conversion capabilities. While exhaust gas boilers are simpler and commonly used in marine and industrial applications, HRSGs are more complex and primarily used in power generation and large-scale industrial processes.

Frequently Asked Questions For What Is The Difference Between Exhaust Gas Boiler And Heat Recovery Steam Genarator?

What Is The Difference Between Waste Heat Boiler And Heat Recovery Steam Generator?

A waste heat boiler deals with highly particulate flue gas and cools down hot ash before disposal. It requires additional equipment like an electrostatic precipitator and ID fan. On the other hand, a heat recovery steam generator uses hot exhaust gas from gas turbines to heat water and generate steam.

What Is Difference Between Boilers And Steam Generators?

The main difference between boilers and steam generators is the design. Steam generators use a single tube coil instead of multiple smaller diameter boiler tubes, resulting in less steel in their construction.

Is Heat Recovery Steam Generator A Boiler?

A heat recovery steam generator is a high-efficiency steam boiler that uses hot gases from a gas turbine to generate steam. It is not exactly the same as a traditional boiler, but it serves a similar purpose in generating steam for various applications.

What Is A Heat Recovery Steam Generator?

A heat recovery steam generator (HRSG) is a high-efficiency steam boiler that uses hot gases from a gas turbine to generate steam. It recovers heat from the waste gas and converts it into usable energy to generate electricity or heat water.

Conclusion

To sum up, while both exhaust gas boilers (EGBs) and heat recovery steam generators (HRSGs) are used to recover heat from hot gases, there are key differences between them. EGBs are designed to cool down hot ash from high-temperature combustion, requiring additional components like electrostatic precipitators and ID fans.

On the other hand, HRSGs utilize hot exhaust gas from gas turbines to heat water and generate steam in a thermodynamic Rankine Cycle. Understanding these distinctions is crucial in selecting the appropriate system for specific applications.

More To Explore

Subscribe My newsletter

keep in touch