Power Plant Modelling

Oxy-Fuel Process and Power Plant Modelling

In order to meet future energy demand and to replace older and inefficient units, a large number of fossil-fuel power plants will need to be built worldwide in the next few decades. Currently, carbon dioxide (CO2) emissions from fossil-fired power generation are major contributors to climate change. Hence, the new generation of fossil-fuelled power plants must be designed to be more efficient, while also including provisions for the capture and storage of CO2, wherever warranted.

Generally, in a thermal power plant, the chemical energy stored in fossil fuels such as coal, fuel oil, and natural gas is converted successively into thermal energy, mechanical energy, and finally electrical energy for continuous use and distribution across a wide range of end users. Thermal power plants incorporate many processes and systems, including fuel handling, combustion, steam generation, flue gas clean-up, and electricity generation. However, due to energy losses, not all of the energy input from the fuel is converted into electricity, and the plant efficiency is in fact a measure of these losses.

coal-fired power plant

Schematic of a coal-fired power plant - Source: Alstom

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Schematic of a coal-fired power plant

Power plant layout - The schematic shows a typical coal-fired power plant with: the boiler, combustion system, denitrification system, steam turbine and generator, dust collector, and desulphurization system.

 

In order to further increase the efficiency and reduce the emissions of the fossil-fuelled power plants, today’s advanced turbines and boiler designs utilize new alloys and operate at supercritical conditions of around 30 MPa and 625oC. In addition, research work is underway to increase the operational temperature to 700oC or even higher. While increasing efficiency is viewed as a “no-regret” strategy, in order to turn the corner on the climate change, the new fossil-fuelled plants should include CO2 capture and storage (CCS) in their strategy.

Progression of Coal-Fired Power Plant Technology: Efficiency vs. CO2 Emissions

Oxy-fuel combustion provides an effective way to burn fossil fuels while allowing the capture of CO2 through efficient physical separation processes. However, advanced near-zero emissions power plants are quickly evolving into highly complex systems and processes. In order to address this magnitude of process complexity and develop the required tools to simulate and analyze these advanced supercritical and ultra-supercritical power plants, CanmetENERGY continues to broaden its unique plant modelling capabilities. These capabilities allow us to assist stakeholders in modelling and simulation for integrated process design, optimization, performance analysis, and new concept development.

Using specialized and custom design modelling software, we have developed advanced process modelling capability. These modelling capabilities analyze and simulate a wide range of air and oxy-fuel combustion options for supercritical steam boiler and coal-fired power plant configurations, flue gas treatment processes, CO2 clean-up and compression, and air separation units, as well as advanced Rankine and Brayton cycle model development. Complete supercritical boiler and balance-of-power models have been set up to simulate entire plant processes, including mass and energy flows, and to study dynamic performance in response to changes in operational variables.

The balance-of-power models can be further evolved into a power plant simulator for engineering studies and research and training purposes.