Current vacancies

Life prediction of power plant components with welds under flexible, thermal-mechanical loadings and operation cycle optimization

Impact of the project:
Your work will hel ensure that the lights stay on in times when society needs it most by preventing failures in critical power generation equipment. 

Background:
The aim of the PhD project is to investigate the creep and creep fatigue behaviours of CSEF power plant steels subject to realistic plant loading cycles.

The current market conditions are such that combined cycle gas turbine (CCGT) plants are now considering double two-shift operation, so potentially accruing upwards of 600 starts per year. The pressure to reduce the extent of pressure system inspections and repairs continues to increase, with the most recent capacity auction clearing prices for generation showing a significant reduction when compared to previous years. For operators of large generation facilities, the key consideration is the through life revenue return, which will guide decisions on new plant builds and any capital investments on plant currently operating. On this basis the need for effective life prediction and condition monitoring tools to support the supply chain (designer, fabricator, operator and technical service provider) is evident.

Over the years, significant development has been made on the 9–12%Cr creep strength enhanced ferritic (CSEF) steels. Traditionally, in material development for power plant components, creep ductility, which can be treated as resistance to damage, has received much less attention. However, the risk of catastrophic failure due to low damage tolerance is a real challenge, in particular, in the situation where mechanical and metallurgical constraints are present. In addition, due to the increasing frequency of cyclic operations, i.e. starts up and shut downs for main steam pipelines of power plants, low cycle creep fatigue failure due to low ductility of the materials has become an important concern.

The aim of the PhD project is to investigate creep and creep fatigue behaviour which takes into account the variable ductility for CSEF power plant steels subject to realistic plant loading cycles, through a comprehensive theoretical, experimental and computational programme.

Specific objectives will include:

  1. Data acquisition and analysis and literature review on the currently available models and assessment procedure.
  2. Experimental investigation of LCF behaviour and microstructure characterization of the candidate power plant steel/weld (possibly MARBN).
  3. Development of a cyclic visco-plasticity model for PM, WM and HAZ which takes into account the cyclic softening and damage.
  4. Application of the model for component assessment using plant operational data and considering typical plant component geometries and plant operator requirements for condition assessment.
  5. Exploring early life contributors to damage such as severe plant operation, impact of poor design and creep brittle properties.

High temperature mechanical testing and physical characterization will be carried out using well-established facility. The theoretical and modelling work will be carried out using finite element package ABAQUS through user defined subroutines.

Funding

Applications are welcome from graduates with a relevant STEM or engineering background. We would like you to have a strong background of Mechanics of Solids and Computational Modelling or the willingness to learn. Furthermore, you will work closely with your industry sponsor giving you plenty of opportunity to gain more industry experience. You should possess good presentation and communication skills and the willingness to learn how to write high quality academic papers.   

We would like you to start October 2022, within the EPSRC Centre for Doctoral Training (CDT) “Resilient decarbonised Fuel Energy Systems”. The studentship which will cover full university fees and a tax-free, enhanced annual stipend to UK candidates. A limited amount of partial funding is available for exceptional international applicants who are highly qualified and motivated. Due to the nature of this funding, the CDT would only be able to cover the cost of the Home fees and therefore the applicant would need to either find alternative funding or self-fund the fee difference.  

Please apply to the University of Nottingham.

Informal enquiries may be sent to Dr Walid Tizani (walid.tizani@nottingham.ac.uk).  Please note that applications sent directly to those email addresses will not be accepted. 

Optimising biomass milling, classification and conveying for enhanced power generation

Impact of the project:
Your work will ensure that we can supply reliable, CO2-free power with the use of plant-based material

Background:
This project will explore the fundamental link between biomass milling, classification and conveying to optimise biomass processing. The project will explore the fundamental science of milling fracture mechanics to develop a test for the critical particle size for comminution through compression for biomass particles. This test will be bench marked against the industry standard bond work index milling test and milling in a lab scale vertical spindle mill.

The fundamental science behind classification will be investigated to ascertain the impact of biomass particle size and shape on classification and linked back to milling fracture mechanics. A model will be developed which can predict if classification will be successful based on the milled product from the grinding bed. An existing rig which examines biomass conveying in pipes will be further developed to analyse a wide range of biomass particle flow conditions.

A novel biomass particle roping rig will be built to investigate roping and its link to biomass particle size and shape. Roping mitigation strategies will be developed, which will then be verified on a laboratory vertical spindle mill with pneumatic classification.

This would be a four-year project based in the new Resilient Decarbonised Fuel Energy Systems CDT based at The University of Nottingham and working alongside Net Zero Research partners. 

We would like you to start in October 2022. Applications are welcome from applicants with a relevent STEM or engineering background. The project will be a mixture of lab based and modelling experiments. You should have a broad interest in renewable and low carbon technologies, and in the application of these technologies. Furthermore, you will work closely with your industry sponsor giving you plenty of opportunity to gain more industry experience. You should also be able to demonstrate excellent written and oral communication skills or a willingness to learn, which will be essential for collaborations, disseminating the results via journal publications and attendance at international conferences.

Funding

The PhD student will work within the EPSRC Centre for Doctoral Training (CDT)  “Resilient Decarbonised Fuel Energy Systems”. In addition to the standard EPSRC stipend and payment of UK fees, there will be a stipend enhancement of £3,750 per annum for 4 years, with £6,000 per annum of funding for research costs and travel. 

To apply, please send a cover letter and CV to Dr Orla Williams (orla.williams@nottingham.ac.uk).  

Recycling of acrylic plastics: understanding how to achieve virgin-quality monomer product from chemical recycling technologies.

Impact of the project:
You will use microwave-based technology to turn waste plastics into the feedstock for chemical processes – high value recycling and avoiding the need for new hydrocarbon feedstock – reducing dependence on oil and gas.  

Background:
We are seeking applicants with a process engineering background to start in Autumn 2022 on a project with Mitsubishi Chemical UK Ltd. The funded studentship is the result of a major expansion of a programme to decarbonise the entire value chain around acrylic polymer manufacturing. Chemical recycling of current and legacy acrylic materials is a key challenge that needs to be met in order to realise the broader decarbonisation programme, and microwave heating has been identified as a key enabling technology that can meet this challenge. Mitsubishi Chemical have partnered with the University of Nottingham to carry out this work due to their world-leading expertise in microwave heating technologies. The partnership aims to better understand the impact of material properties and processing conditions on recycled product and its ability to displace fossil resources in the acrylic manufacturing process. A continuous, industrial-scale demonstration process will be developed towards the end of the programme.

The aim of the PhD project will be to gain better understanding of how both microwave and conventional heating technologies can be used to process waste plastic and produce monomer product that is of sufficient quality to re-use in acrylic manufacture. Working with the industry partner, other PhD students and project team members, you will establish and model concepts for refining feedstock and crude monomer to the required quality, where challenges will be around variable feedstock composition and the separation of close-boiling components. These refining processes will be combined with new technologies for acrylic recycling to produce a number of system-level process models that can be used to establish feedstock-technology-product relationships. These models will in turn be used to direct technology development for recycling processes and to develop a broader industry implementation strategy for recycled acrylic, optimising the acrylic circular value chain.

This is an excellent opportunity for an enthusiastic first or upper second class graduate with a relevant STEM or engineering background to develop expertise and key skills in the sustainable manufacture and recycling of plastics, and to establish relationships with international academic and industrial partners.

The project will be part of the EPSRC-supported Centre for Doctoral Training (CDT) "Resilient Decarbonised Fuel Energy Systems". The student who undertakes it will be one of a cohort of over 50 students in a broad range of disciplines across the Universities of Sheffield, Nottingham and Cardiff.

Please apply to the University of Nottingham. 

Informal enquiries may be sent to Prof. John Robinson (john.robinson@nottingham.ac.uk). Please note that applications sent directly to those email addresses will not be accepted.