Biomass based combined cycle thermal power plant

A Biomass-Fired Combined Cycle Cogeneration System integrates biomass combustion with combined cycle and cogeneration principles to enhance efficiency, reduce emissions, and optimize power and heat generation. Below is a brief description of each component:

Biomass fired combined cycle cogeneration system

1. Heat exchanger,

2. Splitter,

3. Compressor,

4. Gas turbine,

5. Dryer,

6. Combustion chamber,

7. Cyclone,

8. Super-heater,

9. Evaporator,

10. HP drum,

11. Economizer,

12. Economizer,

13. HP pump,

14. Super-heater,

15. Evaporator,

16. MP drum,

17. Economizer,

18. Economizer,

19. MP pump,

20. Super-heater,

21. Evaporator,

22. LP drum,

23. Steam Turbine.

1. Heat Exchanger

A heat exchanger transfers heat from hot gases or fluids to a working fluid without direct contact. In biomass plants, it preheats water or air using the heat recovered from flue gases, improving overall thermal efficiency.

2. Splitter

A splitter divides the working fluid (steam or hot air) into different streams to optimize energy distribution across various subsystems in the plant. It ensures proper allocation of thermal energy for power generation and cogeneration purposes.

3. Compressor

The compressor in the gas turbine system compresses ambient air before it enters the combustion chamber. Higher air pressure increases combustion efficiency and power output.

4. Gas Turbine

The gas turbine burns the biomass-derived gas (syngas or producer gas) to generate mechanical energy, which drives a generator to produce electricity. The hot exhaust gases are used for heat recovery in the steam cycle.

5. Dryer

The biomass fuel used in combustion must have a controlled moisture content. The dryer reduces the moisture level of biomass feedstock, increasing combustion efficiency and reducing emissions.

6. Combustion Chamber

The combustion chamber burns the biomass fuel to produce high-temperature flue gases. It plays a critical role in converting chemical energy into thermal energy for the gas and steam turbines.

7. Cyclone

The cyclone separator removes particulates and ash from the flue gas before entering the heat recovery steam generator (HRSG) or heat exchangers. This prevents fouling and enhances system performance.

8. Superheater

The superheater increases the temperature of steam beyond its saturation point without increasing pressure, improving the efficiency of the steam turbine. High-temperature steam produces more work output in turbines.

9. Evaporator

The evaporator converts water into steam by utilizing the heat from flue gases. It is an essential part of the boiler system.

10. HP Drum (High-Pressure Drum)

The HP drum is a steam-water separator in high-pressure steam generation. It collects and stores steam before sending it to the superheater.

11 & 12. Economizers

Economizers preheat the feedwater by recovering residual heat from flue gases, increasing boiler efficiency and reducing fuel consumption.

13. HP Pump (High-Pressure Pump)

The HP pump increases the pressure of feedwater before it enters the HP drum and boiler system, ensuring efficient steam generation at high pressures.

14. Superheater

Another superheater stage is used to further increase the temperature of steam at different pressure levels to optimize energy conversion in the steam turbine.

15. Evaporator

Another stage of the evaporator to generate medium-pressure steam from water.

16. MP Drum (Medium-Pressure Drum)

The MP drum separates steam and water at an intermediate pressure level before directing steam to further superheating or turbine expansion.

17 & 18. Economizers

Additional economizers preheat feedwater at different pressure levels, improving overall thermal efficiency.

19. MP Pump (Medium-Pressure Pump)

The MP pump increases the pressure of feedwater for the medium-pressure steam generation cycle.

20. Superheater

The medium-pressure steam is further heated before being sent to the steam turbine.

21. Evaporator

A low-pressure evaporator generates steam from water using residual heat from the flue gases.

22. LP Drum (Low-Pressure Drum)

The LP drum separates steam and water at low pressure before sending it to the steam turbine.

23. Steam Turbine

The steam turbine converts the thermal energy of superheated steam into mechanical energy, which is used to generate electricity. The exhaust steam may be used for cogeneration applications, such as district heating or industrial processes.

Working Principle of Biomass-Fired Combined Cycle Cogeneration System

1. Biomass fuel is dried and burned in the combustion chamber, producing hot flue gases.
2. The hot gases pass through a cyclone separator to remove ash and particulates.
3. The clean hot gases enter the heat exchanger and superheater, where they heat the working fluid.
4. The gas turbine receives compressed air from the compressor, mixes it with biomass gas, and generates power.
5. The gas turbine exhaust heat is recovered in the heat exchanger and used in steam generation.
6. The evaporators, superheaters, and economizers work in stages to generate high-, medium-, and low-pressure steam.
7. The generated steam expands in the steam turbine, producing additional electricity.
8. The steam turbine's exhaust steam may be used for industrial heating, district heating, or process steam applications (cogeneration).

Advantages of Biomass-Fired Combined Cycle Cogeneration

• High efficiency: Combines gas and steam turbines for optimal energy conversion.
• Reduced emissions: Biomass is a renewable, low-carbon fuel compared to fossil fuels.
• Waste heat utilization: Cogeneration supplies heat for industrial processes or district heating.
• Sustainability: Uses locally available biomass, reducing dependency on fossil fuels.

This system is widely used in industries like paper mills, sugar mills, and agro-processing plants, where biomass is readily available as a bi-product. Let me know if you need a more detailed analysis or a schematic diagram.