Post on 06-May-2018
2014
1 Seconded from Electricité de France as Deputy Manager of ESKOM Power Plant Engineering Institute
2 Eskom Power Plant Engineering Institute (EPPEI) - Senior Manager
3 Eskom Research Test & Development (R T&D) – General Manager
4 Eskom Technology and Commercial - Technology Division Executive
Eskom Power Plant Engineering Institute (EPPEI) 5-years research strategic plan
Prof Louis Jestin1, Malcolm Fawkes2, Barry Maccoll3, Matshela Koko4
EXECUTIVE SUMMARY
In November 2012, the Eskom Executive Committee approved the creation of the Eskom Power
Plant Engineering Institute (EPPEI) under the Eskom Academy of Learning (EAL). The aim of
EPPEI is to increase the number of engineering specialists by having Eskom Engineers taking
courses and carrying out research at University towards a Masters or Doctorate degree.
Eskom has contracted six leading universities in South Africa in which eight Eskom
Specialisation Centres (SCs) in Engineering have been established. The EPPEI management team
is also supporting the collaboration between these eight SCs and other SA developing
universities. It also facilitates the relationship with Original Equipment Manufacturers (OEMs)
that Eskom are working with and foreign utilities and universities, to ensure that the academic
and research benefits are distributed widely and are focused on the real needs of the power
industry.
The EPPEI academic programme was launched in January 2012 and presently close to 100
Eskom engineers are studying full-time at universities. These students are linked with existing
research initiatives within Eskom currently housed in the Eskom Sustainability Division, under
the banner of RT&D. This research at the universities aims at hosting intellectual property that
Eskom purchased and at further developing it for the benefit of South Africa.
This paper firstly discusses some of the key technical challenges that Eskom is presently facing
and that the research at universities is contributing to address. It also presents the course
curriculum as well as the method used to prepare the research topics in close cooperation
between the Eskom specialists and the Academic supervisors. Then the initial version of the
research orientations taken by the eight specialisation centres for the first 5-years strategy is
given. Some specific inter-university projects aiming at fostering the integration of engineering
activities between these SCs are also mentioned.
CONCLUSION
EPPEI is a novel attempt by Eskom to address the current lack of specialist skills in the organisation in partnership with the leading research universities in South Africa. After two years the first students have finished their research and submitted their theses. Inter-university collaboration has improved and connecting the researchers at universities with their counterparts in the technical divisions in Eskom has resulted in a number of other projects where these researchers interact directly with the Eskom specialists. A number of expert academics, some from abroad, have been recruited and employed by the SCs which already increased the expertise available in South Africa for Eskom and other stakeholders in the power generation sector. The investment and commitment from Eskom in the EPPEI is significant and the benefit to the organisation will be closely monitored.
2014
2 | P a g e
1 INTRODUCTION - ESKOM STATUS AND DEVELOPMENT
South Africa is the largest economy on the African continent. The country’s rich mineral wealth
and associated industries as well as a climate that supports a large farming sector have allowed
for significant development as a modern economy.
The government of South Africa is committed to grow the economy for the benefit of all citizens.
One essential precondition for prosperity is the development of relevant supporting
infrastructure in which sustainable supply of electricity is a key component. The development of
a sustainable power supply system will allow for increased industrial activity and increased
supply to South African citizens, and will support the mechanization of a number of industry
branches.
The supply of power to the economy must not only be cost effective, but also have limited and
controllable impact on the environment. As a state owned utility Eskom is actively working
towards improved cost effectiveness and environmental protection and is closely partnering
with the government in attaining the goals of the National Development Plan.
Eskom was established 90 years ago as a state owned power utility to provide energy at low
cost. The utility supported the growth and development of all South African industries. Between
1960 and 1990 Eskom initiated a very rapid build programme that ramped electricity
production to exceed 35GW. Eskom also developed the relevant transmission infrastructure to
transport and distribute electricity. These capacities resulted in Eskom supplying 95% of all
electricity in South Africa to date.
In 2013 the utility is the owner and operator of about 44GW power generation assets consisting
of 13 large Pulverized Fuel (PF) coal-fired power plants equipped with 87 units, two nuclear
Pressurized Water Reactors (PWR) as well as hydraulic plants and Open Cycle Gas Turbines
(OCGT) complementing the generation system.
Eskom also develops, owns and operates the integrated power transmission network which is
spread across South Africa. The transmission network is inter-connected with the neighbouring
countries. The distribution network delivers power to final customers and local municipalities.
Figure 1 indicates the locations of the power generation plants as well as the transmission
network main lines on the map of South Africa.
2014
3 | P a g e
Figure 1: Southern Africa grid map and power station location
As can be seen in Figure 2, and despite the aforementioned activities, South Africa has been experiencing a shortage of margin in power generation since 2007 due to its successful economic development and following the rising demand in electrical energy.
As a consequence and in collaboration with the government, an ambitious strategy has been
developed to “keep the lights on”.
The main components of this strategy include:
1. Improved energy management and energy savings in cooperation with customers.
2. Improved asset maintenance to ensure that faults and inefficiencies are detected early and
corrected to increase plant availability.
3. Plant modifications for operation beyond their original design lifetime and to fulfil new
environmental regulations.
4. Growth of the power supply by developing additional generating capacity.
2014
4 | P a g e
The following paragraphs briefly outline some of the flagship projects that are currently on-
going under this strategy. Some of the projects were decided approximately 10 years ago and
are close to delivery.
Figure 2: South African power supply and demand over the 2 last decades
Gas 1 (2 442MW) - A number of open cycle gas turbines (OCGT) were added in the Western
Cape to the existing Ankerlig and Gourikwa sites to meet peak load demands. The additional
capacity of the Gas 1 project is 1 040MW which increases the total Open Cycle Gas Turbine
installed capacity to 2 442MW.
Return-to-service Projects - A total of 23 previously mothballed coal-fired units at Camden,
Grootvlei and Komati power stations are close to being fully re-commissioned and returned
to service (RTS). These plants still need some more modifications to enable further
improvement in plant availability, reliability and efficiency as well as compliance with new
environmental regulations.
Ingula Pumped-Storage Scheme (1 332MW) - Ingula Pumped Storage Scheme is under
construction in the escarpment of the Little Drakensberg, South Africa. The plant is a 4 x
333MW reversible pump-turbine powerhouse that consists of the upper Bedford Dam and
the lower Braamhoek Dam, which are 4.6 km apart and connected by underground tunnels.
Medupi Coal-Fired Power Station (4 800MW) - Medupi is a greenfield coal-fired power plant
project situated in Lephalale consisting of six units with gross nominal capacity of 800MW
each. This power station will be the fourth largest coal-fired power plant and the biggest
dry-cooled power station in the world.
Kusile Coal-Fired Power Station (4 800MW) - Kusile is the second most advanced coal-fired
power plant project in Eskom after Medupi. Similar to Medupi, the station consists of six
units each rated at approximately 800MW. It will be the first power station in South Africa to
utilise Flue Gas Desulphurisation (FGD).
Sere Wind Farm (100MW) - The Sere Wind Farm, a key renewable energy project located
near Vredendal in the Western Cape, is near completion. This project will have a capacity of
100MW consisting of approximately 50 wind turbines spread over an area of 16 square
kilometres.
2014
5 | P a g e
Solar 1 (100MW) - This concentrated solar power (CSP) project, will be located near
Upington in the Northern Cape and will benefit from the highest solar irradiation in the
country. The plant comprises of a heliostat field and power tower circulating a binary salt
mixture. The heat is transferred to a conventional water-steam Rankine cycle plant. Plant
performance and efficiency will be determined upon completion of the engineering studies.
Life extension of numerous plants is on-going. These engineering studies need highly skilled
reverse engineering and plant operation status to be conducted to ensure that sound
investment decisions are made. A large part of the existing 87 units that make up the present
coal generation fleet requires retrofits to adapt to the new environmental legislation to
reduce dust, sulphur dioxide and nitrogen oxides emissions by 2015 and 2020.
Upgrade and development of the South African transmission and distribution grids are being
carried out to meet demand and to adapt to the new power generation being built.
Projections estimate power production to increase to 75GW by 2025 from the existing 44GW of
installed capacity for which all available technologies can be applied using either wind, solar,
coal and nuclear.
The major driver for power generation from renewable energy resources world-wide is
mitigation of climate change due to carbon emissions. However, two other drivers can be even
more important in the current South African context: implementation time and funding access.
Building large coal-fired or nuclear power stations can take a decade from the pre-feasibility
study to commissioning, while wind farms, utility-scale PV installations and CSP plants can be
planned, built and commissioned in much shorter time. Financing renewable energy power
plants, as opposed to coal-fired and nuclear plants, seems less cumbersome and funders will
frequently accept lower returns. The cost of electricity from renewable energy resources has
reduced significantly over the last five years due to an increase in the rollout of renewables over
the last decade (economies of scale) and the general international economic downturn.
In order to comply with the future demand, the large deposits of coal found in the northern
regions of the country present an opportunity to develop clean coal technologies for base load
applications. Development of renewable energy technologies has already started in the RSA.
Wind and especially solar resources will certainly take a larger share in the future generation
mix while the intermittent nature of these renewable energies will have to be thoroughly
addressed. CSP with thermal storage could complement other renewable generation as well as service
the evening peak that is currently covered by expensive OCGTs. The cooling capabilities along the
southern and western coasts as well as the relatively long distance from the northern coal
power stations also suggest further nuclear developments. All these options are going to form
the future sustainable energy mix of South Africa.
Taking into account the power generation locations relative to the demand areas also need
thorough investigation to adapt and develop the transmission and distribution grids to fully
master the power system dynamic behaviour under all conditions. A more distributed power
system as well as smart grids will certainly play a major role to reduce the full system cost.
2 BRIDGING THE SKILLS GAP
Eskom management has identified skills shortage as a key challenge to be addressed for
effective growth of the power system. The last large power generation unit was commissioned
by Eskom two decades ago. Most of the experts who were part of this build scheme have left
while those remaining are approaching retirement.
2014
6 | P a g e
The New-Build projects, which are taking place and will continue for the next decades to come
create a real opportunity to develop the skills of new engineers. This can also reduce the
dependency of the South African economy on foreign technologies and expertise which are
presently mostly provided by foreign equipment manufacturers.
The numerous graduate engineers recently employed by Eskom and its partner companies in
South Africa need to be skilled to design, manufacture, erect, commission, operate and maintain
the new fleet of Eskom power plants and transmission network.
For a power utility such as Eskom, which has to deal with complex systems, it is essential that
the engineers have a global overview of the systems and processes they are working on. It is also
crucial that they fully understand and master the design criteria, the quality of manufacturing,
the modes of operation and the quality of maintenance that all impact the cost of electricity
through capital expenditures, primary energy consumption and other operation and
maintenance costs including environmental impact.
The current EPPEI programme is concentrating on improving the understanding of the global
power chain over the complete lifetime of power projects, which nowadays can last for more
than one century depending on the technology. This requires a high level of postgraduate
education at masters and doctoral levels.
In order to achieve these goals, EPPEI is building a strong and long term partnership with
academic institutions at six leading South African universities to align their curricula to service
the needs of the power industry.
Table 1: The eight Eskom SCs developed at six leading universities with their partner
universities in the EPPEI framework.
Area of specialisation Lead university Partner University
Energy Efficiency UCT NMMU
Combustion Engineering WITS UJ ( To be confirmed)
Emissions Control NWU VUT & Venda
Materials Science – Mechanics UCT NMMU
Asset Management UP TUT
High Voltage (AC) WITS VUT
High Voltage (DC) UKZN DUT
Renewable Energy Technology SUN CPUT
On the one hand, the course curriculum of undergraduate students at university is already being
adapted to address the power generation and transmission systems so as to create an early
student interest in the energy field and encourage them to pursue post-graduate studies.
On the other hand the SCs funded by Eskom at the six leading universities and their partner
universities in SA already constitute a strong body of knowledge and research for power
activities at the postgraduate level.
The annual target is that 60 Eskom engineers at bachelor level who have experience of two to
four years in the company are encouraged to join the EPPEI program full time for a two or three
year period to obtain a masters or doctorate degree, respectively. Prior to their registration at
2014
7 | P a g e
the universities, they attend courses at the Eskom Academy of Learning (EAL) for one year in
four blocks of four weeks, each. After passing their examinations they are allocated a research
topic devoted to an Eskom problem and directed to one of the eight SCs at the lead or partner
universities where they carry out their research under the auspices of an industrial mentor and
an academic supervisor.
This research carried out by Eskom engineers is aimed at fostering the relationship between
Eskom and university specialists. EPPEI management also intends to start the cooperation
between these SCs and the power systems OEMs, foreign power utilities and foreign universities.
It is envisaged that the EPPEI structures will provide skills development to other Eskom’s
partners in South Africa and later even throughout the rest of Africa.
It is worth keeping in mind that the power currently generated by Eskom makes up to 40% of all
power generated on the African continent. It is expected that this example of skill development
in South Africa could become beneficial to the rest of Africa’s 900 million inhabitants that should
be around 1.8 billion in three decades from now.
3 STRUCTURE OF EPPEI
EPPEI offers a compelling value proposition to the three key stakeholders:
Eskom and its employees
EPPEI offers practical and professional post-graduate engineering education that provides
the opportunity to deepen knowledge in a key specialisation area and thus create a clear
career path for individuals.
Local universities
EPPEI provides access to research funding and increased collaboration between different
universities as well as between universities and industry.
South Africa community
EPPEI can broadens and deepens South Africa’s expertise base in selected technologies. This
is in line with the government’s goal to gradually transform the economy into a knowledge-
based economy while at the same time spawning a service industry around the power
industry, thereby increasing earnings from the export of technology and manufactured
products.
3.1 EPPEI Programme Governance
The Governance of EPPEI has been structured using a three-tier approach with a Steering
Committee and a Technical Committee that meets 2 times annually in addition to a full-time
management team.
The Deans of the six leading universities serve on the Steering Committee which is chaired by
the Eskom Division Executive in Technology. This committee meets once a year. It reviews the
progress of EPPEI and gives the general strategic orientation to the EPPEI program.
The academic and industrial coordinators of the eight SCs as well as the Eskom RT&D
management, the EPPEI management and the EPPEI Junior Enterprise serve on the Technical
Committee. It meets twice a year and is chaired by the EPPEI Programme Manager. It deals with
the course curriculum and the research programs, which are respectively conducted at Eskom
Academy of Learning (EAL) in Midrand and at the EPPEI SCs at universities.
2014
8 | P a g e
The Management Team is an internal body of EPPEI that organises and manages the EPPEI
operation according to the decisions made at the Steering and Technical Committees in
accordance with the Eskom Academy of Learning rules.
As the programme develops relationships with foreign universities, OEMs, other utilities and
related organisations, these will be included in the committees. It is also envisaged that more
structured and organisational work will be directly carried out at university level in order to
make the structure to be self-sufficient and sustainable in the long run.
3.2 EPPEI Research Governance
It is essential for the research carried out at the EPPEI SCs to be focused on the Eskom
engineering needs and well aligned to the research carried out elsewhere in Eskom RT&D and
other academic institutions.
To accurately identify the Eskom engineering needs and report back on the research conducted
during the previous year, an EPPEI conference is held at the beginning of each new academic
year attended by the academic and industrial specialists as well as the current EPPEI students
and representatives of previous intakes.
Eskom researchers and representatives from the Eskom Centres of Expertise (CoEs) are key
stakeholders in this conference to ensure that Eskom problems are accurately defined and the
resulting research well-structured to solve them.
Figure 3: Three tiered governance structure of EPPEI programme between Eskom
technology division and universities.
2014
9 | P a g e
To facilitate the organisation and reporting, the research and workshop is organised in three
clusters (Figure 4) as follows:
Figure 4: Research at the eight university SCs is organized in three Clusters: Power
Generation, Electrical Engineering and Crosscutting Component Areas.
3.2.1 Inter-university research synergies
Figure 5 illustrates a power plant using a Pulverised Fuel Rankine cycle of the type that
currently produces more than 90% of South Africa’s electricity. As an example the legend of
Figure 5 indicates the complementarity nature of the eight EPPEI SCs towards research on this
type of power plant. It is also worth noticing that the Rankine cycle power plants type, which is
used for nuclear, gas combined cycles and even CSP, produces more than 70% of electricity
worldwide and constitutes the core part of the research for power generation in EPPEI at this
stage.
Based on the above Rankine cycle example, projects are being identified to reinforce integration
and inter-university cooperation on common objectives namely: to increase plant reliability,
availability and efficiency. The following topics are proposed:
Numerical Tools Development
This project will look at all the numerical tools that are being developed and used by the
students in the EPPEI programme at different universities. Students conducting research need to
ensure that the software used in their projects is aligned to the software policy within Eskom.
This project will have to ensure that tools in the following areas of research are centrally
coordinated. Areas that the group will initially investigate are: Computer Assisted Design (CAD)
2014
10 | P a g e
1 - Energy Efficiency at University of Cape Town for the global water-steam and air flue-gas process design and operation monitoring in steady state and transient regimes.
2 - Combustion Engineering at Wits University for the pulverized fuel combustion in the furnace and the heat transfer between the flue gas and water-steam circuit along the flue gas path.
3 - Flue gas cleaning at North West University for removal of dust, sulphur and nitrous oxides.
4 - Material and Mechanical Engineering at University of Cape Town to advise in the choice of most appropriate high temperature materials, to investigate the failure mechanisms and propose repair strategies.
5 – Asset management at Pretoria University to optimise the long term maintenance strategies of the strategic components of the plant.
6 & 7 - Electrical engineering at Wits and Kwazulu Natal Universities for the electrical component design, operation monitoring and maintenance.
8 - Plant cooling at Stellenbosch University either by air dry or wet technologies.
Figure 5: Process layout of a typical Pulverised Coal Rankine cycle power plant in which
all EPPEI SCs contribute at research. Note: Numbers 1, 4, 5 , 6 &7 relate to the entire
system.
tools, process flow modelling tools in steady state and transient regimes, Computational Fluid
Dynamics (CFD), Finite Element Analysis (FEA), general engineering calculation tools, electrical
component modelling and electrical network modelling tools.
Plant Performance and Testing (P&T)
The group will focus on ensuring that measurements taken to evaluate plant performance are
conducted correctly. This group will ensure that any testing conducted during the EPPEI
programme is in line with the processes used within Eskom. This project will become a central
source of information on testing and will allow Eskom to standardize protocols used and
develop skills in this critical field.
This project should also investigate the improvement of the on-line monitoring of plants using
the EtaPRO tool that Eskom is rolling out on all its Pulverized Fuel (PF) power stations. The new
measurement techniques and monitoring tools should enable a better condition monitoring of
the plant for all main components.
2014
11 | P a g e
Generation-Transmission Coordination
Eskom’s vast electrical network is a constantly evolving system. The complexity of the network
and the management thereof should become another inter-university project, especially when
more dispersed and remote renewable energy production is developed. This project will ensure
that research related to the grid is relevant to the needs of Eskom for improved dynamic
stability behavior and also provide detailed information for plant design and operation.
3.2.2 EPPEI Training Course and Research Coordination
To fulfil its objective, the EPPEI programme ensures that students are given academically
challenging problems and courses that ensure that participating engineers become well
rounded.
The course curriculum and research topic preparation were developed to ensure that the
programme could be completed within two years for students completing MSc degrees.
Programme recruitment begins one year prior to registering at a university. During this
recruitment period Eskom employees complete four blocks of courses on a part-time basis that
are required to start the programme.
As can be seen in Figure 6, in parallel to this course curriculum, the academic and industrial
specialists develop the research topics relevant to the technical problems to be solved within the
Eskom organisation. These problems result from research completed by previous students and
relevant operational problems that need to be resolved. Once Eskom’s problems have been
identified and the results of the previous years’ research been shared between the industrial and
academic specialists during an early year workshop, the academic specialists are responsible for
the formulation of the new research topics for the next intake of masters and doctoral (PhD or
Tech) degree candidates.
Figure 6: A generic EPPEI year is cadenced by the two above parallel tracks: (i) Delivering
courses curriculum to the candidates in four blocks and (ii) Preparation of research topics
between the Eskom and academic specialists and allocation of topics to the students who
have been successful in the exams by mid of the year prior to joining the university.
2014
12 | P a g e
Figure 6 also shows the interaction between the course curriculum and the project preparation.
The research topics are presented to the successful candidates by the middle of the year. Topics
are allocated to the candidates in close collaboration between the Eskom and academic
specialists and the relevant Business Line Manager of the candidates, taking into account the
specific engineering backgrounds of the candidates such as: electrical, mechatronics, mechanical,
chemical, materials, civil, etc., and the needs of Eskom and the relevant Business Unit.
Once in agreement, a three-party contract is signed between the Candidate, his/her Industrial
Mentor, who must be a specialist of the research area and, the Academic Supervisor who is also a
specialist in the area, preferably from the university where the student is going to be registered.
This is finalised by September of the year prior to registration at the university where the
research is going to be carried out.
3.2.3 EPPEI Coursework
Courses must ensure that students understand topics at an academic level and build on this
expertise through advanced courses in selected fields before starting their research. The courses
need to ensure that all disciplines have the opportunity to further their understanding in the
over-all engineering subject matter and secondly further their understanding in their specific
engineering discipline.
The courses, offered by EPPEI at the Eskom Academy of Learning (EAL) in Midrand, have the
following objectives:
Refreshing fundamental knowledge in physics, mathematics, and engineering
sciences applied to power system engineering.
Establishing basic drivers of development, operation and maintenance of power
projects.
Understanding of basic design and operation criteria of power generation and
transmission processes and components.
Familiarising engineers with everyday numerical tools processes and procedure
used at Eskom
The fundamental courses are mainly delivered by lecturers from the six leading partner
universities while the applied courses can be delivered by industrial specialists from Eskom or
EPPEI partner companies. These courses can also be attended by individuals who are not
directly involved in the EPPEI programme to develop their knowledge in process engineering.
After completion of the EPPEI courses students who are joining Pretoria and Stellenbosch
University are still required to successfully complete further postgraduate courses before
starting to work on their research projects.
To avoid conflict with the university calendar as I happened for the first intake of EPPEI
students in 2012, the coursework has been re-structured in four blocks, which are all delivered
in the year before being registered at university. The exam results from the first two blocks of
courses form part of the selection criteria to screen prospective candidates for final acceptance
into the EPPEI programme. These blocks are all delivered before candidates start their research
at the various SCs. As illustrated in Figure 6, students who successfully complete the first two
blocks of courses are given a research topic mid-year prior to joining the relevant Specialisation
Centre.
This gives students the opportunity to start a literature review and to prepare a project plan and
gather the resources required for their research project. However, the successful completion of
2014
13 | P a g e
four blocks of courses is required before students can undertake their research degrees by full
dissertation.
2014
14 | P a g e
4 STRATEGIC PLANS FOR THE EIGHT SPECIALISATION CENTRES
4.1 Energy Efficiency at University of Cape Town (UCT)
It is the aim of the Energy Efficiency SC to develop skills and tools needed to help ensure more
available, reliable, energy efficient and more environmentally friendly electricity production
within Eskom by focusing on complete plant process flow modelling and analysis.
These models will enable steady state and transient design analysis as well as normal and
accidental operation analysis. It will include all necessary control and instrumentation logic.
More refined local models of the fluid-structure interaction of some specific components will
also be developed and integrated into the complete plant model where needed. Modelling will
focus on the Rankine water-steam cycle, It will also take into account the boiler or steam
generator heat exchangers with the fluegas..
Figure 7: Role of the Energy Efficiency SC within EPPEI from component design to plant
integrated process operation and monitoring.
It is envisaged that the plant models developed will serve as the integrator/federator for the
work done by other SCs within EPPEI. Outputs from plant models will serve as inputs to SCs
requiring thermo-hydraulic process conditions. Further integration can be done with grid
models developed at the two electrical SCs to eventually have a complete macro system model
that could predict any scenario response on the national grid, and its local influence on plants in
terms of participation, availability and remaining life.
Finally, key plant performance indicators identified by this SC could be fed back to the on-line
monitoring systems to better operate and maintain the operating plants. The plant model will
also serve as a high fidelity simulator to train operators, technicians and engineers in efficient
use and design of power plants. This will improve the root cause analysis capability, and the
ability to conduct cost-effective trade-off studies of plant modifications or improvement.
TRANSIENT Control
Instrumentation Capabilities
Refined time and space analysis
Integrated plant models
Plant data, KPI
Monitoring tools, training
COMPONENT Ageing
Reliability Energy
efficiency
STEADY STATE Design
Monitoring Root cause
analysis
2014
16 | P a g e
4.2 Combustion Engineering at WITS
In existing coal plants the measurement and instrumentation equipment installed on the key
components making up the full combustion systems such as fans, wind-boxes, mills, pulverised
fuel (PF) pneumatic transport, burners, air heaters and other water-steam heat exchangers, soot
blowers and start-up firing system are quite limited and sometimes inaccurate. In addition to
that the control devices themselves have also their own drawbacks and inaccuracies which
make it difficult to control the operation set-points of the components and even sometimes to
control the total boiler behaviour. It then becomes really difficult to monitor on-line the
combustion system to detect early and diagnose abnormal situations which tend to cause un-
reliable and inefficient operation.
On the other hand international and local environmental standards require implementation of
NOx reduction technology in all existing and New-Build plants. The basic requirement for
adequate low-NOx burner operation is to master well the coal and air quality and distributions
to the individual burners. In particular the combustion process in the wall fired boilersneeds
accurate coal and air flow measurements to be optimally controlled in any situation due to
continuous variations in coal quality used and plant capacity load.
An urgent need exists to improve the measurement and online monitoring of:
Coal mass flow rates and coal quality , especially ash and moisture content
Milling plant performance to control fuel air ratios, particle size and mass flows
Air streams to wind boxes, burners and air heaters
Heat transfer from flue gases to the air and water-steam circuit.
Figure 8: Pulverized fuel boiler showing 4 burners in operation during plant start-up
The SC strives to improve understanding of local coal quality impact and predicting the effects
on coal-fired power plant. Research is focused on current Eskom requirements to:
Improve and grow a repository of skills and knowledge of existing plant
Create skills and tools to design, operate and maintain plants
Ensure future plants are Cleaner, Available, Reliable, Efficient and Safe (CARES).
Achieve world class output in combustion engineering related technologies.
Retain a highly skilled engineering base in Eskom to create a healthy fleet for current and future power generation using state of the art technology.
Host the combustion system design intellectual property purchased by Eskom
Attract local manufacturers to build and supply burners for the local market.
2014
17 | P a g e
Provide a continuous improved bouquet of experimental facilities in heat transfer, combustion technology and thermodynamics.
4.3 Emission Control at North West University (NWU)
Eskom operates coal-fired power stations which annually emit approximately 230 Million tons
(Mton) of CO2 and more than 1Mton of SO2 into the atmosphere. International pressure and
local legislation controlling pollutant emissions such as SO2, particulates and NOx have become
more stringent over the past decade, as illustrated in the Table below by the emission limits
imposed on SA coal-fired power stations since 1 April 2010.
Eskom’s response is to firstly monitor and understand the nature of emissions from its existing
fleet and to implement effective ways of emission reduction without making electricity
unaffordable in the South African context. Emissions control must be considered to optimise
and, if necessary, modify old technology to perform beyond design capabilities for the existing
fleet. It must also ensure that emissions from plants meet increasingly strict emissions
standards that have been set by government for New-Build power stations currently under
construction.
Table 2: Solid fuels (excluding biomass) emission standards in SA for combustion
installation above 50 MW– From Department of Environmental Affairs [No. 248, 31 March
2010] - National environmental management: air quality act, 2004 (act no. 39 of 2004)
Substance or mixture of substances mg/Nm3 of pollutant
(In flue gas at 10% O2 , 273 K and 101.3 kPa)
COMMON NAME CHEMICAL SYMBOL NEW PLANT Existing Plants
2015 2020
Particulate matter PM 50 100 50
Sulfur dioxide SO2 500 3500 500
Oxides of Nitrogen NOx expressed as NO2 750 1100 750
The primary focus of this SC is to understand existing emissions of SO2, NOx, CO2, and Hg
particulates into the local atmosphere from Eskom power stations in order to retrofit current
processes.
In addition, the SC will work closely with Eskom and the OEM technology providers to ensure
that new power plants meet future emissions requirements. The objectives will be to ensure that
Eskom is at the forefront of understanding emission mitigation technologies and the total
emissions into the atmosphere from its processes.
Figure 9: Coal stock pile at a power station
2014
19 | P a g e
Figure 10: Damage and cracking indicated
with Digital Image Correlation
4.4 Materials Science – Mechanics at the Centre for Materials Engineering at UCT
Power generating plants operate under highly demanding conditions that include high
temperature, high stress, oxidation and corrosion, and complex tribological environments. In its
most basic form, plant reliability is critically dependent on the integrity of a broad range of
engineering materials (mostly metals) that make up structures, machines and systems within
the plant.
Given the anticipated plant life-time, the
material integrity is expected to remain within
the design performance for periods often in
excess of 300 000 hours. Consequently,
accurate characterization of the material
condition with regards to the damage level, as
well as prediction of the damage that occurs
during exposure to operating conditions, and
concomitant loss in design properties, is
necessary. The situation is further complicated
by repair activities, particularly those involving
welding, that alter the existing materials that
may compromise or reduce integrity.
New material developments are required to
handle these challenges and an industry must
be developed to manage the use of new
materials during design, construction and
maintenance while existing plants continue
operating to produce the most energy at the
lowest cost.
The activities of the SC are directed towards the
most urgent challenges in this field.
The focus is on high temperature behaviour, fatigue and corrosion, with emphasis on materials
utilised in power generation. Research will explore the influence of service operating
environments on performance in order to:
better predict life of engineering materials and components in power generating plant,
optimize the selection of materials for plant construction, improve manufacturing
technologies including welding and
improve the reliability in monitoring material and component integrity.
2014
20 | P a g e
4.5 Plant Asset Management at the University of Pretoria
This SC is developing skills and techniques to monitor and manage key components affecting the
availability of Eskom plant assets such as: turbines and fans, generators, boilers (piping and
tubes), transformers, mills, and bulk solids plant.
Management of such complex assets requires deep understanding of asset management
principles enhanced by highly specialised asset integrity analysis and evaluation capabilities.
This is a multidisciplinary challenge which draws expertise from diverse fields such as machine
condition monitoring, signal processing, artificial intelligence, statistics, structural dynamics,
finite element analysis and fatigue, and integration of these principles into life cycle
management and decision environment. The monitoring, analysis and management techniques
will be integrated with work done in the Energy Efficiency SC in order to optimise efficiency and
availability of Eskom plant.
Once critical assets are identified, carefully selected operational data are acquired. The data
leads into condition monitoring process which forms the basis for diagnostics processes to
identify the nature and extent of incipient faults.
There is an increasing need to interpret this information for a forecasting strategy point of view,
e.g. to estimate remaining useful life of assets. This information, together with an understanding
of the load profile on the asset, provides input for life cycle decisions and interventions. All of
this happens in an environment where immense amounts of data need to be stored and be
accessible in standardised formats with a high level of integrity.
The implementation of the EtaPRO software throughout Eskom provides a significant
opportunity for further improvement in the plant condition monitoring tools that could be
implemented as well as for accessing on-line data from plant and using this data in the research
tasks.
The main thrusts of this SC are outlined in the following simplified schematic:
Figure 11: Main research thrusts at the Plant Asset Management SC.
2014
21 | P a g e
4.6 High Voltage (AC) at WITS
This SC aims to build up the Eskom skills base by presenting courses and conducting research in
the area of High Voltage (AC) which includes power generation, transmission, distribution and
use.
Generator insulation integrity of both stator and rotor windings is crucial for reliable generator
operation which under high temperature and mechanical stresses and vibration conditions leads
to steady degradation of the insulation. Partial discharge testing is one of the most important
tests conducted on generator winding insulation, but test result interpretation and determining
the timing for major repairs are difficult. Generator transformers also operate in demanding
environments, which accounts for a large portion of the current Unplanned Capability Loss
Factor (UCLF).
Transmission research focuses on performance of transmission lines in environments that
include; lightning strikes, switching surges, power frequency over-voltages, pollution, and on
reliable operation of large transmission networks. Expertise in lightning performance of
transmission lines is crucial for line designs that have acceptable performance (limited number
of flashovers due to lightning). Switching surge performance is particularly important to live-
line work where human safety must be ensured. Good pollution performance requires insulator
selection that considers pollution performance of various types of insulators, i.e. ceramic or
polymeric. Reliable operation of large networks involves maintaining acceptable transient
stability, small-signal stability, voltage and frequency stability.
In the area of distribution, research focuses on improved monitoring and protection of
equipment such as transformers, which have historically been run-to-failure. Stresses on
transformers have increased due to unmonitored electricity theft, nonlinear loads and
unbalanced sharing of single-phase loads between the three phases. With increased penetration
of renewable generation in distribution, better monitoring and control is essential. The presence
of customer nonlinear loads emphasises the importance of power quality and electromagnetic
compatibility studies.
Figure 12: Factors contributing to oil paper insulation ageing.
Paper Degradation
PaperAcids &
HydroperoxidesOilTemperature Temperature
Oil Oxidation
Sludge &
Varnish
Metal catalysts
Oxygen Water
Paper chain
scission
2014
22 | P a g e
4.7 High Voltage (DC) at University of Kwazulu Natal (UKZN)
This SC has two operational High Voltage Laboratories one focused on Direct Current (DC) and
the other on Alternating Current (AC). The combination of the two laboratories along with a
powerful Real Time Digital Simulator (RTDS) and Smart Grid Simulator, is well suited to support
Eskom with its expanding grid design and operational requirements.
The impact of new resources including renewable electricity sources and possibly nuclear
energy, into the existing grid is important and will naturally result not only in growth, but also in
a more complex grid. This will put increased pressure on South Africa to develop and consider
different technologies in order to deliver electrical power efficiently and reliably.
Eskom views High Voltage Direct Current (HVDC) systems as an enabler for future expansion of
the existing grid. There are a number of potential HVDC systems, a bipole connecting Limpopo to
Gauteng provinces, and a separate bipole through Kwazulu-Natal, and an increase in capacity of
the existing system from the Cahora Bassa dam in Mozambique.
The strategic plan is to develop laboratories, the intellectual competence and the design ability
of Eskom and UKZN in line with the grid capacity upgrade. HVDC systems research will focus on:
circuit breaker technology
conversion technology
system configurations
implementation of new components and
technologies
condition monitoring
line configurations
clearances
insulation materials for transformers,
overhead lines and cables
power line communication
Figure 13: Overcurrent protections for a distribution system simulated using
RTDS/RSCAD
2014
23 | P a g e
4.8 Renewable Energy Technology at Stellenbosch university
In the framework of the recent successful procurement of electricity from renewable energy
independent power producers in South Africa and Eskom’s own Sere wind farm and Upington
CSP plant, some of the key technical challenges that need to be addressed by Eskom engineers in
the short to medium term include:
Integrating renewable energy power stations with variable output into the national grid;
Forecasting the electricity production from these power stations;
Operating and maintaining the Eskom renewable energy power plants to optimise the electricity production and reduce the cost;
Deal with some unique South African challenges such as dry-air cooling for CSP plants and cleaning of mirrors and panels in dusty, arid conditions.
South Africa has an abundance of renewable energy resources that can be utilised for electricity
generation such as solar, wind, ocean, bio and other renewable sources. Figure 14 indicates the
high level of direct normal irradiance in especially the Northern Cape Province that is typically
50% more than in Spain and 20% more than in North America.. To support the Eskom
development in renewable energy, the key research areas for this SC are:
Support to design, operation and maintenance of wind farms and CSP plants, including the optimisation of electricity production
Feasibility studies for renewable energy power plants
Tender specifications and procurement processes
Overseeing construction, commissioning and grid integration
Figure 14: Annual Direct Normal Irradiance of South Africa