Safe use of flammable refrigerants-Modeling concentrations of the leaked refrigerants in case of accidental emissions in different scenarios
In order to achieve the climate neutrality goals and the forthcoming F-gas regulation, it is important to promote the transition toward low-GWP refrigerants. Almost all low GWP refrigerants are flammable and the safety issues of these refrigerants (hydrocarbons and HFOs) prevent them from being used in larger systems. This master thesis is a risk assessment project and the purpose is to develop and improve the knowledge required for the safe use of flammable refrigerants in refrigeration and heat pump systems. The project will evaluate and quantify the refrigerant concentration around a plant in connection with unintentional emissions. In addition, the project will evaluate various available technical solutions for detecting refrigerant leakage, and also the solutions and methods to reduce the risk of occurring flammable concentrations. The overall goal is that the results to be used as a basis for developing new national and international standards.
Scope of thesis:
To model and identify the ignition risks and quantify the concentrations of the leaked refrigerants in case of accidental emissions in different scenarios such as domestic heat pumps, restaurant kitchens and other commercial stores that use different types of refrigeration units. An air dispersion model should be used to determine if leaking refrigerant would reach the concentrations required for ignition in several commercial refrigeration systems. The investigation of gas dispersion during unintentional emissions in different application scenarios requires careful modeling and the use of simulation tools makes it possible to model different emission scenarios.
Using CFD tools:
The innovative aspect of this study is CFD-modelling of releases of refrigerants. A limited amount of studies have been performed, but the effects of the type of refrigerant, differences in density, effects of temperature of the released fluid, effects of boundary conditions in terms of air movements, room size, possible effects of fans, effects of release of inert gases to mitigate the buildup of flammable concentrations etc. have not been investigated in full.
Number of students: one.
Contact person, supervisor and examiner:
Supervisor:
