26443 Modeling of expansion devices for heat pumps and chillers
Richtingen: Master of Science in Electromechanical Engineering


A heat pump represents a system of different components that is able to transfer heat from low temperature energy source to the high temperature energy sink. For doing so, the heat pump unit is using an external power supply as well as a specific type of working medium. In the residential heating system application, air to water heat pumps are the most commonly used type. For accurate energy performance assessment methods application and appropriate sizing of the unit, reliable and easy parameterized models of the heat pumps system are necessary.


This project aids in achieving sustainable development goal (SDG) 7: affordable and clean energy, by enabling the replacement of fossil fuels by renewable energy sources for the building sector

This thesis is in collaboration with Daikin Europe NV.


The goal of this thesis is to develop a model for expansion devices (capillary tubes, electronic expansion valves), which only uses the refrigerant state and measurement data with compressed air. This model should be broadly applicable in a variety of refrigerant conditions. Specifically, it should be able to handle both subcooled refrigerant as well as two phase refrigerant inlet states. Additionally, it should be valid for both in choking and non-choking conditions.

In order to generate the required data to develop the model, an existing refrigerant setup will be modified / a refrigerant setup will be built.

The aim is to develop a model that can predict the refrigerant mass flow through an expansion valve, based on a measurement with compressed air.