Research team
Expertise
Reducing the energy use in buildings is essential to reach carbon neutrality and combat the effects of climate change. Traditional energy systems in buildings, which mainly used fossil fuels such as natural gas and oil for heating, need to be replaced with renewable energy sources. For buildings, district heating and heat pumps are typically used as replacement for fossil fuel boilers. The refrigerants in these heat pumps can also contribute to global warming and new fluids are currently being researched and introduced. Two-phase flow and heat transfer occurs in the different components of heat pumps, but is still not well understood. Numerical CFD simulations of these phenomena have become feasible in recent years, which will drastically improve our fundamental knowledge. My research focuses on two tracks: numerical simulations of complex (two-phase) flow and heat transfer and dynamic modelling of building energy system components. In the first track computational fluid dynamics (CFD) simulations are use to analyze flow and heat transfer in different components such as heat exchangers, piping and ducts. The second track focuses on developing dynamic and accurate models of building energy components such as thermal energy storage systems, which are necessary for detailed building energy simulations, component sizing and control.
Models and methodology for the design and control of residential district heating systems with thermal energy storage
Abstract
District heating for building applications will need integrated thermal energy storage systems in order to be able to include more renewable energy into their operation. Thermal energy storage models are nowadays lacking accuracy or need too much calculation time, to be able to use them for district heating network topology optimization. They show the same deficiencies when control during operation is considered. This project aims at developing fast and reliable models for thermal energy storage systems and integrate them into district heating models. Secondly the project aims to develop an heuristic topology optimization method which will allow to design quickly and reliably a district heating network with thermal energy storage. In a final phase the thermal models will be used to define control strategies for district heating networks by simulation in Modelica.Researcher(s)
- Promoter: T'Jollyn Ilya
Research team(s)
Project type(s)
- Research Project
CFD simulations of energy systems and complex flow phenomena.
Abstract
Heat pumps are an essential part of sustainable building energy systems. New refrigerants are being introduced to reduce the impact of refrigerant leaks on global warming, but the influence of these new refrigerants on the boiling heat transfer in the evaporator is currently impossible to predict without measurements. The goal of this research project is to use numerical CFD simulations to evaluate nucleate pool boiling heat transfer. This has recently become feasible due to the advances in computational power. In this project, a numerical framework will be developed to run these simulations. Using the framework, the effect of new refrigerant fluid properties, but also of the boiling surface material and microgeometry will be analyzed.Researcher(s)
- Promoter: T'Jollyn Ilya
- Fellow: T'Jollyn Ilya
Research team(s)
Project type(s)
- Research Project
Numerical simulation of nucleate pool boiling heat transfer.
Abstract
Heat pumps are an integral part of the future sustainable building energy systems and are already taking up a substantial portion of the (newly) built sector. In the evaporator, a liquid refrigerant flows that is evaporated to a vapour. Although boiling heat transfer has been researched for almost a century, no consensus is yet available in the scientific community on which (fluid) parameters affect boiling heat transfer. As new refrigerants with lower global warming potential are still being introduced, testing is required for each fluid to analyse the heat transfer performance. Using computational fluid dynamics simulations, new insights will be gathered in the behaviour of the boiling process. The goal of this research is to develop a numerical framework to simulate heat transfer during nucleate pool boiling and evaluate the influence of fluid properties and other boundary conditions on the heat transfer rates. With this framework, the heat transfer rates during nucleate pool boiling of different fluids with varying properties can be predicted, as well as the influence of boundary conditions such as the boiling surface material properties and (micro)geometry. This will enable faster and improved design of evaporators, which are essential an part of systems such as heat pump, chillers and power generation through organic Rankine cycles.Researcher(s)
- Promoter: T'Jollyn Ilya
- Fellow: Whiting Mitchell
Research team(s)
Project type(s)
- Research Project