Thermophysical properties of Refrigerants

Scope of project, aims, approach, focus

The majority of modern refrigeration processes are based on the vapour-compression cycle, which involves a working fluid that is depressurised and evaporated in the cold part of the cycle (where heat is absorbed), and compressed and condensed in the warm part of the cycle (where heat is rejected). Unfortunately, these working fluids are associated with significant lifetime environmental impacts, which can include stratospheric ozone depletion and a contribution to global warming. These impacts are quantified by means of two metrics: the ozone depletion potential (ODP) and the global warming potential (GWP). Following the discovery of the Antarctic ‘ozone hole’ in the 1980s, refrigerant working fluids with near-zero ODP have been introduced worldwide. Unfortunately, most of these fluids suffer from high GWP and a transition to new working fluids with both zero ODP and low GWP is required. The new fluids must meet numerous other criteria related to their physical properties, safety and cost. The proposed research aims to improve the efficiency of the available refrigeration processes by providing more accurate physical properties of the refrigerants. These properties will be used to design the refrigeration cycles and the associated process units more effectively. Improving the efficiency of these processes will result in less energy consumption and CO2 emission and mitigate the impacts on global warming.

This study focuses on determining the thermophysical properties of selected pure refrigerants and some of their blends through experimental measurements and modelling studies. The research should be conducted in three steps:

Literature review: to check the quantity and quality of the experimental data available in the literature and find the gaps that need to be filled.

Experimental part: this part focuses on measuring the thermophysical properties of selected fluids (i.e. density, viscosity, and vapour liquid equilibrium) to fill the gaps in the literature data and provide enough information for the modelling part. Experimental measurement of this study will be performed with the experimental facilities in three well-equipped laboratories of the hydrate, flow assurance and phase equilibria research group at Heriot-Watt university.

Modelling study: Before using any thermodynamic models, they must be validated against reliable literature and experimental data generated during the measurement phase. This procedure will be performed during this part of the study. In addition, If required, models’ parameters will be upgraded to improve the performance of the thermodynamic models.

The outcomes of this study are expected to be published in high-quality peer-reviewed scientific journals and presented at leading conferences related to the subject. 

The supervisory team will consist of Dr Pezhman Ahmadi and Dr Rod Burgas

For informal enquiries, please email Dr Pezhman Ahmadi ([Email Address Removed]) 

Eligibility

This scholarship is available to Home students only unless co-funding can be demonstrated (as detailed under funding notes).

To be eligible, applicants should have a first-class honours degree in a relevant subject or a 2.1 honours degree plus Masters (or equivalent experience). Individual projects may include additional eligibility criteria, in which case, this will be stated under the project description.

We recognise that not every talented researcher will have had the same opportunities to advance their careers. We therefore will account for any particular circumstances that applicants disclose (e.g. parental leave, caring duties, part-time jobs to support studies, disabilities etc.) to ensure an inclusive and fair recruitment process. 

How to apply

To apply you must complete our online application form.

Please select the relevant PhD Petroleum Engineering and include the full project title, reference number and supervisor name on your application form. You will also need to provide a CV, a supporting statement (1-2 A4 pages) outlining your suitability and how you would approach the project, a copy of your degree certificate and relevant transcripts and an academic reference.

Please contact Dr Pezhman Ahmadi ([Email Address Removed]) for informal information.

If you have any general queries about the applications process, please contact [Email Address Removed]

Timeline

 The closing date for applications is 10 April 2023 and applicants must be available to start in September 2023.