Eskom Power Plant Engineering Institute (EPPEI) 5 years ... · 2014 1 Seconded from Electricité de France as Deputy Manager of ESKOM Power Plant Engineering Institute 2 Eskom Power

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.

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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.

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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.

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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.

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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.

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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

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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.

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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.

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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)

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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.

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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.

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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

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four blocks of courses is required before students can undertake their research degrees by full

dissertation.

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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

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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.

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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

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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.

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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.

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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

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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

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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

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Research and development to facilitate technology transfer to South Africa operations.