VGB POWERTECH 7 (2021) - International Journal for Generation and Storage of Electricity and Heat

VGB PowerTech 7 l 2021
Digital transformation of the coal sector
Digital transformation
of the coal sector
The future intelligent power generation enterprise
will be a data-driven (F i g u r e 3 ),
Cloud-enabled enterprise in which decisions
in all areas of the business are informed
by live streams of data and connected
by a single digital platform at plant or
fleet level. The digital platform will be connected
to almost everything from energy
production and transport, power generation,
transmission and distribution (T&D),
sales and services, and beyond. The digital
platform can run complex power generation
operations efficiently, leading to optimal
operational and environmental performance,
improved flexibility, reliability, security
and profitability. Digital technologies
can also be applied to coal mining, helping
to automate and optimise coal production,
improve operational efficiency, environmental
performance, workers’ safety and
production workflow at reduced costs.
Benefits of digitalising
power generation
Fuel supply management Mills Boiler Emissions
- Fuel management advisor - Mill optimiser - Combustion optimiser - Emissions advisor
- Low load advisor
- Soot cleaning optimiser
- Headers lifing advisor
Total plant Rotating assets Accessories Environmental control system
- Plant efficiency advisor - Steam temperature advisor
- ECS advisor
- Plant flexibility advisor - Start-up optimiser
- ECS optimiser
- Start-up advisor
- Generator health advisor
- Turbine vibration advisor
- Rotor stress advisor
- Turbine lifetime advisor
- Turbine start-up optimiser All auxiliaries
Cooling tower Steam turbine Generator Electricity
Fig. 4. Optimising a coal-fired power plant using digital technologies (GE, 2017a).
Digital plants can operate at optimal efficiencies
leading to a substantial reduction
in CO 2 emissions from coal power generation
(F i g u r e 4 ). The cost of electricity is
also lowered due to reduced fuel consumption,
optimised O&M, improved reliability,
availability and flexibility resulted from
digitalisation. The digital transformation
towards a sustainable and more efficient
power generation that provides cleaner
and cheaper electricity with minimal environmental
impacts is compatible with the
UN Sustainable Development Goals of
good health and wellbeing for all, affordable
and clean energy for all, and actions to
combat climate change and its impacts, as
well as responsible consumption and production.
In short, digitalising coal power
plants with innovative technologies will
increase their efficiency, affordability, reliability,
and sustainability.
l
VGB-Standard
Construction, Operation and Maintenance
of Flue Gas Denitrification Systems (DeNOx)
VGB-S-014-2011-EN (VGB-S-014-2011-DE, German edition)
DIN A4, Print/eBook, 186 Pages, Price for VGB-Members € 240.–, Non-Members € 360.–, + Shipping & VAT
After facilities for reduction of dust emissions were deemed to be state-of-the-art worldwide, beginning
in 1970, tests were performed in Germany for the reduction of emissions of SO 2 and NO x . The
first measures for the use of combustion technology to limit nitrogen oxide development during
combustion were performed, which resulted in lower NOx emissions at new sites. The 1983 German
regulation on large combustion plants (GFAVO) prescribed the emission limit value for both existing
and new power stations, in accordance with what was feasible at the time. After the transportation
sector, NOx emissions by the power station sector were number two on the list of main emission
sources, with around a 28% portion of total emissions. For this reason, the Federal Republic prescribed
a dynamic modification rule for the limitation of nitrogen oxide emissions: “The possibilities
for further reducing emissions by means of combustion technology or other measures representing
the state-of-the-art are to be exploited.”
VGB-Standard
Construction, Operation
and Maintenance of
Flue Gas Denitrification
Systems (DeNOx)
VGB-S-014-2011-EN
The result of this regulation was that, in 1984, significantly lower emission limit values were prescribed
by decree of the Minister of Environment responsible for new and existing facilities larger than
300 MW th . These turned out to be lower than what was had been achieved based on the state of technology in Japan. The new limit
values led to a costly retrofit campaign of DeNOx facilities at hard coal-fired power stations in Germany as well as in Austria. Some
EU countries followed suit with delays and low requirements, which were widely adhered to using primary measures. Few EU countries
(e. g. The Netherlands, Denmark) followed with SCR-retrofits.
The requirement targets “limitation of NOx emissions” for oil, gas and brown-coal firing systems were achieved using solely combustion
technology measures, i.e. without resorting to downstream processes. Secondary measures are required for hard coal and
heavy oil-firing systems, due to their higher burning temperature, which will be addressed in this VGB-Standard.
In 1997, European air quality guidelines implemented the requirements of the World Health Organization (WHO) regarding the
reduction of nitrogen oxides and ozone. Nitrogen oxides are recognized as critical precursors to ozone development at the height
of summertime solar radiation. According to the WHO, betterment of air quality in terms of both substances should be pursued. In
regions with high ozone values in the US, for example, this initially led to the primary SCR technology utilized being operated only
during the summer period.
After 2001, the retrofitting of existing facilities with denitrification technology became obligatory, requiring that all large coal-fired
power stations in the EU be retrofitted by 2016. In the meantime, international power station projects in developing countries and
newly industrialized countries who wish to receive development money from the World Bank are tested to determine whether facility
planning fulfils the requirements for environmental protection facilities in accordance with the “best available technology”.
More than 20 years of operational experience and procedural developments already exist for today’s SCR technology, and have been
compiled in this VGB-Standard.
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