Planning and testing of an experimental test rig for Two-phase flow experiments in a heat pump cycle

Alternative energy sources are more in the spotlight than ever before, not least because of the climate crisis, which has recently become more and more noticeable. In order to achieve a gradual exit from the use of fossil energy sources, renewable energy sources must be pushed in development. One type of these renewable energy sources is the heat pump. Here, freely available environmental energy is used together with electrical energy in a heat pump circuit. From this, energy is produced that is used to heat or cool living spaces. It is also used to produce domestic hot water. In order to make heat pump cycles even more efficient, research projects at the Austrian Institute of Technology are focusing on the use of phase change materials (PCM). Refrigerant, water and PCM are used together as a latent heat storage unit. Hot refrigerant causes a phase change of the PCM and stores heat. This heat is later to be released back to the water. The abbreviated name RPW-HEX stands for Refrigerant-PCM-Water heat exchanger. It describes such a latent heat storage unit. Samples of such RPW-HEX have been designed, which differ mainly in their internal structure. A component test rig will be developed. This has the task of testing samples in order to better understand the behaviour of the media in the internal structure. The component test rig should be a heat pump. Its design makes it possible to swap and examine the RPW-HEX samples. The following work gives a general overview of the relevance of the heat pump in the current climate situation. It also describes the operation of a heat pump in general and explains how an RPW-HEX is applied in this operation. The design of a component test rig is planned in 2D and subsequently in 3D. Standard measuring sections for temperature sensors will be designed. These are planned as well as mass flow sensors as part of the heat pump circuit. Furthermore, the individual components that are used for the component test rig are discussed. Heat pump operating modes are defined to simulate specific situations for the RPW-HEX. The switching between the different working modes is defined by the switching of built-in valves. The planned component test rig is built and presented in the course of this work. Furthermore, it is considered how an RPW-HEX can be effectively filled with PCM. The results of the work are discussed at the end and an outlook on the experiments on the component test rig is given.