STERG Website – Solar Thermal Energy Research …sterg.sun.ac.za/wp-content/uploads/2012/09/Topics-for...The linear Fresnel reflector plant concept is another focus technology of

PhD: MIng Navorsing Tesis onderwerp:

MEng Research Thesis topic: X

MIng Gestruktureerd Projek: MEng Structured Project:

X

Afdeling / Division: (please underline which is applicable) Design & Mechatronics / Mechanics / Thermo fluids / Renewable Energy

Dosent / Lecturer: Mr RT Dobson

TITEL / TITLE: Stand-alone (off-grid) solar Stirling dish electrical power supply unit

Beskrywing van onderwerp / navorsingsveld: Description of topic / research field: This objective of this project is to develop a stand-alone electrical power supply system for off-grid rural communities. The ultimate outcome of the project is to produce a locally manufactured knock-down do-it-yourself kit suitable for mass distribution throughout Africa. This is a relatively complex project requiring the use of a number of different disciplines. The following projects have so far been identified: 5.1 Test and characterise the performance of a 25 kWelectrical and 100 kWthermal Stirling engine 22 V 50 Hz power unit.

5.2 Theoretically simulate, design manufacture and test a 3 kW free piston Stirling engine electrical power generating unit. (Ivan Deetlefs) 5.3 Construction and control of a 12

m2 parabolic reflector dish for the free 3 kW free piston Stirling engine electrical power generating unit. (Gerro Prinsloo) 5.4 Dynamic FEM structural analysis including fluctuating wind loading and structural optimisation 5.5 Make a 3 kW Eskom-grid compatible electrical supply unit. 5.6 The evaluation of a locally manufactured 3 kW solar Stirling dish system for African enlightenment. 5.7 Industrialization/commercialisation for local manufacture of a self-standing 3 kW electrical power system 5.8 CFD simulation and analysis of a Stirling Dish fluctuating under fluctuating wind conditions.

Spesifieke voorvereistes: / Specific requirements: None

Befondsing beskikbaar / Funding available: Adequate funding for bursaries (and scholarships) and equipment is available


X


Dosent / Lecturer: Mr RT Dobson

TITEL / TITLE: Diurnal (24 hour day and night time) simulation of solar water heating and cooling systems

Beskrywing van onderwerp / navorsingsveld: Description of topic / research field: A longer and more descriptive title could be the “Diurnal (24 hour day and night time) simulation of the transient and dynamic behaviour of integrally-coupled natural circulation thermosyphon-type solar water heating and water storage systems”. Although many solar water heating systems have been built and installed throughout the world there are still many unresolved issues relating to the transient simulation of integrated systems, especially in so far as natural circulation-type systems are concerned. A number of more detailed specialised separate student topics

are available, such as: 1.1 Flow visualisation; including plume formation and entrainment, stratification, inversion, inlet flow-distribution, and inlet flow distribution and baffling. This project will also allow one to get a good understanding of the global earth systems engineering and processes and the management thereof. 1.2 Theoretical modelling; including one-dimensional and Boussinesq approximations, specific CFD simulations, two-dimensional two-phase non-equilibrium transient and dynamic simulation. 1.3 Experimental verification and validation, and energy loss coefficient determination for low flow rates, as is the case in thermosyphon systems.

1.4 Cost optimisation simulation model for a solar collector and storage system.

Spesifieke voorvereistes: / Specific requirements: None

Befondsing beskikbaar / Funding available: Adequate funding for bursaries (and scholarships) and equipment is available

Typical solar water heating and

storage system

PhD: X MIng Navorsing Tesis onderwerp: MEng Research Thesis topic:

X MIng Gestruktureerd Projek:

MEng Structured Project: X


Dosent / Lecturer: Any suitable supervisor in the department. Contact Paul Gauche with a proposal and advice on a suitable supervisor.

TITEL / TITLE: Open solar thermal project

Beskrywing van onderwerp / navorsingsveld: Description of topic / research field: Any suitable solar thermal energy project that fits into the research done in STERG or that may make a difference in the way that energy is used in South Africa.

1. Concentrating solar power (CSP) 2. Solar water heaters (SWH) 3. Process heat, desalination, other

4. Other

Spesifieke voorvereistes: / Specific requirements:

Befondsing beskikbaar / Funding available: Self-funded or through funding obtained outside of the research group

PhD: x MIng Navorsing Tesis onderwerp: MEng Research Thesis topic:

x MIng Gestruktureerd Projek:

MEng Structured Project: x


Dosent / Lecturer: Prof Thomas Harms, Prof Theo von Backström, Eskom chair, others (depending on topic suitability and availability)

TITEL / TITLE: Concentrating solar power (CSP): Linear Fresnel reflector pilot plant research

Beskrywing van onderwerp / navorsingsveld: Description of topic / research field:

The linear Fresnel reflector plant concept is another focus technology of the solar thermal energy research group.

Research focuses on a proposed 2 MW pilot plant for the Western Cape but the technology has been identified for

process heat use as well as for hybridization of existing coal power stations.

Project 1: Research and development of a direct steam receiver. Theoretical and experimental work is required to understand and control the two phase flow problem for saturated or superheated steam turbine application.

Project 2: Development of a linear Fresnel concentrator for process heat. This project is a continuation of an existing

project that shows much promise.

Project 3: Power plant modeling to assess the suitability and requirements of a linear Fresnel collector field to augment

energy to a conventional coal power station. Spesifieke voorvereistes: / Specific requirements: The student should be comfortable with computer programming for topics that require this.

Befondsing beskikbaar / Funding available: Funding for students is available from STERG for a limited number of students





Dosent / Lecturer: Mr Paul Gauché, Prof Theo von Backström, Prof Hanno Reuter, Prof Albert Groenwold, Prof Gerhard Venter, Eskom chair, others (depending on topic suitability and availability)

TITEL / TITLE: Concentrating solar power (CSP): Central receiver pilot plant component research


The SUNSPOT plant concept devised by Prof DG Kröger is a focus technology for the solar thermal energy research

group. Research focuses on a proposed 5 MW pilot plant. Multiple projects will be available as listed here or elsewhere

in the topic list.

Project 1: Thermal energy storage system using natural (eg. rock) or other sources. This project requires development

of storage system concepts through theoretical and experimental work involving thermal cycling to about 600 °C.

Modeling of system by fundamental analysis, DEM, CFD, Flownex or other tools. Experimental work using high

temperature and flow facilities in the department and research group. Exploratory trips for materials may be required.

Project 2: Heliostat module optimization for cost based on any number of factors including structural, drivetrain,

control, optical, wind loading, dual use and minimal impact of land. This project requires theoretical

development/optimization as well as experimental validation using the solar roof laboratory. This project can be

combined with a Sasol funded R500 000 heliostat field to be deployed in 2013.

Project 3: System thermal and thermodynamic modeling for a 5 MW SUNSPOT pilot plant. This project would be

complimentary to an existing PhD project and look at more detail on the optimization of the receiver and/or storage

system and/or hybridization with backup fuel. Experimental validation on some aspects may be required depending on

the final objective.

Project 4: Heliostat ray tracing software development and validation continuing on a ray tracing tool developed in

STERG. Parallelization, optimization and tuning for central receiver plants all potentially in scope.

Spesifieke voorvereistes: / Specific requirements: The student should be comfortable with computer programming for topics that require this.




MEng Structured Project:


Dosent / Lecturer: Prof Thomas Harms, Prof Theo von Backström, Eskom chair, others (depending on topic suitability and availability)

TITEL / TITLE: Characterization and calibration of a revised prototype sky radiance meter


There is a fast growing local and international demand for frequent and reliable ground observations of solar

radiation. In particular, there is need for measuring the angular dependence of solar radiation over the hemisphere;

and over as many reference sites as is feasible.

A breakdown of the project is as follows:

1. Review the existing prototype (this is a sky radiance meter that can measure direct solar irradiance and radiance at

any point in the sky dome.

2. Work with CSIR and a company (such as Parsec) to design an upgrade of the prototype: conditioning electronics,

temperature compensation, introduction of filters for spectral measurements (the spectral measurements is

necessary component in most CSP, PV applications and yet is often neglected).

3. Development of a Sky Scanner: the sky scanner will be designed for rapid scanning (perhaps scope for a masters

project?)

4. Development of an algorithm for optimal scanning: this will be a partial task for a PhD candidate. A heuristic

scanning algorithm is needed to realise an optimum scan of the sky for radiometric measurements. The algorithm

will be tested with the sky scanner. Depending on prior art, may be a patent? If patentable, it will be a joint

between SUN and CSIR.


Befondsing beskikbaar / Funding available: The collaboration fund is covered by the South Africa National Research Foundation (NRF) and the Deutsche Forschungsgemeinschaft (DFG). There is place for a post graduate student to spend 3 weeks in Berlin, Germany on characterization and calibration of a revised prototype sky radiance meter. The student’s grant will cover travel, accommodation and subsistence.





Dosent / Lecturer: Paul Gauche, Prof Theo von Backström , Prof Albert Groenwold, Eskom chair, others (depending on topic suitability and availability).

TITEL / TITLE: Concentrating solar power (CSP): Scenario modeling for short to long term rollout of CSP in SA


CSP is one of the three major renewables in the South African integrated resource plan. In order for transmission and

resource planning, scenario modeling is becoming increasingly important. These scenarios require a variety of

disciplines and methods to be considered. These projects are by nature theoretical (typically limited or no experimental

work).

Project 1: Scenario modeling with a focus on thermodynamics of plants but including consideration of other key

resources and constraints. Use of geographic information systems (GIS) will be part of the modeling. Strategic

assumptions for the future will be required.

Project 2: Mathematical robustness and optimization modeling considering the resources and constraints mentioned

for Project 1 above. Spesifieke voorvereistes: / Specific requirements: The student should be comfortable with computer programming






Dosent / Lecturer: Prof Thomas Harms, Prof Theo von Backström, Mr Robert Dobson, Eskom chair, others (depending on topic suitability and availability)

TITEL / TITLE: Concentrating solar power (CSP): Supercritical CO2 or other fluids for proposed CSP technology


The use of CO2 as working fluid in solar power plant has been proposed as a method to achieve higher efficiency at a

lower receiver temperature. This project requires a thermodynamic or thermo-economic investigation into the

application of CO2 as closed cycle working fluid. The project requires a detailed investigation into applicable

turbomachinery (turbine and pumping/compression) and/or thermodynamic modeling of the cycle accounting for the

cyclic nature of the sun.

Spesifieke voorvereistes: / Specific requirements: The student should be comfortable with computer programming for topics that require this.


PhD: MIng Navorsing Tesis onderwerp: MEng Research Thesis topic:




Dosent / Lecturer: Dr JE Hoffmann

TITEL / TITLE: Solar Radiation, Heat Transfer and Pressure drop in Porous Media

Beskrywing van onderwerp / navorsingsveld: Description of topic / research field: Concentrated solar power (CSP) with thermal storage has the potential to supply all South Africa’s future energy needs. Existing plant typically use molten salts as heat transfer fluid, and a conventional Rankine (steam turbine) cycle to generate electricity. Worldwide, supply of salts is limited. The SUNSPOT cycle proposes the use of a Brayton (gas turbine) cycle during the day, storing the waste heat in a rock bed to drive a Rankine cycle at night. The efficiency of the Brayton cycle is driven by the maximum temperature that can be obtained at the receiver. The cycle is quite sensitive to the pressure drop across the receiver. Provided that the desired receiver temperature of 800 °C + can be achieved, the SUNSPOT cycle is an attractive addition to current CSP technologies. Gases have poor heat transfer characteristics, and it is a challenge to achieve the desired temperatures. Enhancing heat transfer usually comes at the expense of increased pressure drop. Porous media have excellent blackbody characteristics, and it may be used in combination with optically transparent materials is a receiver. The aim is to develop, test and optimize porous media for heat transfer and pressure drop.

Spesifieke voorvereistes: / Specific requirements: B Eng (Mechanical), else Heat Transfer, Thermodynamics and Fluid Mechanics

Befondsing beskikbaar / Funding available: Negotiable






TITEL / TITLE: Concentrated Solar Power Tower Receiver

Beskrywing van onderwerp / navorsingsveld: Description of topic / research field: Concentrated solar power (CSP) with thermal storage has the potential to supply all South Africa’s future energy needs. The SUNSPOT cycle proposes the use of a Brayton (gas turbine) cycle during the day, storing the waste heat in a rock bed to drive a Rankine cycle at night. The efficiency of the Brayton cycle is driven by the maximum temperature that can be obtained at the receiver. The cycle is quite sensitive to the pressure drop across the receiver. Provided that the desired receiver temperature of 800 °C + can be achieved, the SUNSPOT cycle is an attractive addition to current CSP technologies. Gases have poor heat transfer characteristics, and it is a challenge to achieve the desired temperatures. Enhancing heat transfer usually comes at the expense of increased pressure drop. Furthermore, high temperatures and thermal cycling can lead to radiation losses, thermal stress, fracture and sealing problems in pressurized receivers. This project aims to address issues identified with pressurized receivers, and to resolve some of them. Several receiver concepts have been proposed and tested with varying success worldwide. These range from cavity receivers, open volumetric receivers, particle receivers and pressurized volumetric receivers. Different routes have been identified to improve on current receivers. The project aim to move the receiver design pass the “proof-of-concept” phase to the point where it is ready for prototype development. This should also be a milestone en route to full commercialization of the SUNSPOT cycle.

Spesifieke voorvereistes: / Specific requirements: B Eng (Mechanical), else Heat Transfer, Thermodynamics & Fluid Mechanics

Befondsing beskikbaar / Funding available: Negotiable (maximum 3 masters, and 1 Ph D)






TITEL / TITLE: Heat Transfer Fluids for Concentrated Solar Power Tower

Beskrywing van onderwerp / navorsingsveld: Description of topic / research field: Concentrated solar power (CSP) with thermal storage has the potential to supply all South Africa’s future energy needs. The SUNSPOT cycle proposes the use of a Brayton (gas turbine) cycle during the day, storing the waste heat in a rock bed to drive a Rankine cycle at night. The efficiency of the Brayton cycle is driven by the maximum temperature that can be obtained at the receiver. The cycle is quite sensitive to the pressure drop across the receiver. Provided that the desired receiver temperature of 800 °C + can be achieved, the SUNSPOT cycle is an attractive addition to current CSP technologies. Using air as process fluid negates the need of a secondary heat exchanger between the receiver and turbine. Gases have poor heat transfer characteristics, and it is a challenge to achieve the desired temperatures. Enhancing heat transfer usually comes at the expense of increased pressure drop. Furthermore, high temperatures and thermal cycling can lead to radiation losses, thermal stress, fracture and sealing problems in pressurized receivers. Existing plant typically use thermal oils or molten salts as heat transfer fluid, and a conventional Rankine (steam turbine) cycle to generate electricity. Oils are flammable, and break down above temperatures of about 400 °C. Salts require trace heating at ambient temperatures. Worldwide, supply of salts is limited. Liquid metals (Na, K and eutectic mixtures thereof) provide excellent heat transfer characteristics, but are highly reactive when exposed to water. Public perception is strongly biased against it. Explore the use of an alternative heat transfer fluid that is affordable, safe, and environmentally friendly to overcome the problems posed by air in the receiver.

Spesifieke voorvereistes: / Specific requirements: B Eng, BSc Degree

Befondsing beskikbaar / Funding available: Negotiable


MIng Gestruktureerd Projek:



Dosent / Lecturer: Prof HCR Reuter

TITEL / TITLE: CFD investigation of the effect of cross-winds and temperature inversions on the performance of natural draft cooling

towers

Beskrywing van onderwerp / navorsingsveld: Description of topic / research field: Wind and temperature inversions can dramatically reduce the performance of large cooling towers as found in power, petro-chemical and process plants, significantly affecting plant performance. To maintain output, more coal must be burnt leading to increased pollution. Numerical (CFD) investigation of the air flow patterns about and through such plants is required to determine the influence of distorted air flow patterns on the performance. By introducing practical and cost effective modifications to such cooling towers (extended platforms, windscreens, etc.) significant improvements in performance and a corresponding reduction in pollution should be possible.

Spesifieke voorvereistes: / Specific requirements: An excellent academic record and a passion for Computational Fluid Dynamics (CFD).

Befondsing beskikbaar / Funding available: Funding is available for 1 student - Terms and Conditions apply


MIng Gestruktureerd Projek:



Dosent / Lecturer: Prof HCR Reuter

TITEL / TITLE: Performance evaluation and enhancement of hybrid or deluged cooling systems

Beskrywing van onderwerp / navorsingsveld: Description of topic / research field: Hybrid or deluged dry-cooling systems are currently considered to be the leading water re-cooling technology when ground space is limited, water-costs are high, and visible plumes are not tolerated. The general objective is to investigate the performance chanacteristics of different finned and bare tube bundles with and without deluging and to develop models to evaluate performance.

Spesifieke voorvereistes: / Specific requirements: An excellent academic record and a passion for experimental work in a laboratory.

Befondsing beskikbaar / Funding available: Funding is available for 1 student - Terms and Conditions apply

PhD: MIng Navorsing Tesis onderwerp:

MEng Research Thesis topic: x


x


Dosent / Lecturer: Prof AB Sebitosi

TITEL / TITLE: Evaluating the optimum conversion technology for concentrator solar power (CSP) for a South African context.

Beskrywing van onderwerp / navorsingsveld: Description of topic / research field: CSP is a fast emerging renewable energy technology and is particularly attractive for South Africa which receives some of the highest DNI (direct normal insolation) solar radiation levels in the world. Basically various geometry configurations of mirrors are used to concentrate solar power to heat a central receiver or a group of receivers. Typically this power is used to create steam that runs a turbine which subsequently operates an electric power generator. This model is identical to the traditional coal power plant with its attendant transmission losses from a central location en route to a remotely located consumer load. However this concentrated heat could also be used directly by the final application. Moreover the power usage would be onsite and bypass the need to construct expensive transmission infrastructure and recurrent power loss in transmission.This latter option is particularly attractive given that South Africa’s mining sector is one of the major consumers of electricity and one may question the wisdom behind converting heat energy to electricity if the final requirement is smelting for example. Attractive as this option may appear the current south African norm remains electric usage and no critical evaluation for such a potent alternative has been undertaken and published. This project will look at the energy conversion and consumer technologies for CSP and develop a decision making tool to advise an investor as to which technology to use in a given South African context.

Spesifieke voorvereistes: / Specific requirements: Passion in clean energy and a sustainable environment

Befondsing beskikbaar / Funding available: NRF and TESP funding on a first come basis


X MIng Gestruktureerd Projek: MEng Structured Project:


Dosent / Lecturer: Dr J van der Spuy

TITEL / TITLE: The simulation and testing of an axial flow fan for air-cooled condenser application

Beskrywing van onderwerp / navorsingsveld: Description of topic / research field: The use of direct dry-cooled condensers in power generation systems is a means of ensuring sustainable water usage. The accurate prediction of axial flow fan operation in the air-cooled condenser (ACC) is essential during the design phase of such a system. Axial flow fans are tested according to specific fan test procedures. Previous investigations that looked at modelling the performance testing of such a fan in CFD have shown specific problems to exist. One of these is the modelling of the open inlet to open outlet configuration of the BS 848 type A fan test facility. This investigation should look at the modelling of an actual ACC fan installation and compare it to the modelling and testing of such a fan according to the BS848 standards.

Spesifieke voorvereistes: / Specific requirements: Meganiese Ing. CFD 414

Befondsing beskikbaar / Funding available: Volle projekkostes en beursgelde


Befondsing beskikbaar / Funding available: Funding is available in the form of bursaries from the Centre for Renewable and Sustainable Energy Studies




Dosent / Lecturer: Prof TW von Backström

TITEL / TITLE: Rock bed thermal energy storage system configuration

Beskrywing van onderwerp / navorsingsveld: Description of topic / research field: Energy storage is the key to the successful roll-out of renewable energy. A major advantage of concentrating solar power (CSP) systems is the possibility of storing thermal energy. This technology is very effective in returning the stored energy. Previous students have investigated the effect of rock shape and size on pressure drop and heat transfer in rock beds. They have also investigated the durability of various types of rock. The objective of the proposed thesis is to configure a model rock bed, based on the information available. The emphasis will be on the structure and construction of the complete system, including the inlet and exit ducting. A physical model should be built and the system should be simulated using the flow network code Flownex or similar.


Befondsing beskikbaar / Funding available: Bursary may be available




Dosent / Lecturer: Prof TW von Backström, Dr J van der Spuy

TITEL / TITLE: Axial flow fan blade sweep angle

Beskrywing van onderwerp / navorsingsveld: Description of topic / research field: Blade sweep has been used in axial flow fans to reduce noise and improve efficiency. The proposed study comprises the systematic experimental and computational investigation of the effects of axial, circumferential and chordwise sweep on axial fan performance and noise.


Befondsing beskikbaar / Funding available: Bursary may be available

Documents

STERG Website – Solar Thermal Energy Research …sterg.sun.ac.za/wp-content/uploads/2012/09/Topics-for...The linear Fresnel reflector plant concept is another focus technology of