Process heating is the main energy consumer within the industrial sector. With the supply of process heat being dominated by the combustion of fossil fuels, major changes have to be made to fulfill the European Green Deal. Electrically driven high-temperature heat pumps are a promising technology to replace these fossil-fuel driven boilers through industrial waste heat recovery and revalorization. Selection of suitable working fluids and heat pump cycle architectures are crucial to enhance performance and operating conditions (e.g. reduce compressor outlet temperature or compression ratio) of these heat pump systems. Possible architectures are for example: cascaded cycles, vapour-injected cycles or cycles using internal heat exchange and/or ejectors, as displayed in Figure 1. There is a lack of simulation and optimization for these types of cycles.
A numerical framework for single-stage high-temperature heat pump cycles has been developed in advance, allowing for simulation and optimization of heat pump cycles. The goal of this thesis is to study different cycle configurations and extend the framework with more advanced thermodynamic cycles, enabling for higher performance and/or more feasible operating conditions. The different cycle architecture will be thermodynamically compared based on typical boundary conditions.
By allowing an increased performance of high-temperature heat pumps the primary energy demand (i.e. electricity) can be reduced. Furthermore, widespread adoption of high-temperature heat pumps will be accelerated. Therefore, this topic contributes to Sustainable Development Goal 7 (Affordable and clean energy) and 13 (Climate action):