Optimale Auslegung von Wärmepumpensystemen für Bestandsgebäude

  • Optimal design of heat pump systems for existing buildings

Vering, Christian; Müller, Dirk (Thesis advisor); Elbel, Stefan (Thesis advisor)

1. Auflage. - Aachen : E.ON Energy Research Center, RWTH Aachen University (2023)
Book, Dissertation / PhD Thesis

In: E.ON Energy Research Center : EBC, Energy Efficient Buildings and Indoor Climate 114
Page(s)/Article-Nr.: Online-Ressource : Illustrationen, Diagramme

Dissertation, RWTH Aachen University, 2023


To protect the climate, the 21st century urgently requires sustainable energy use in all sectors, pushing the replacement of conventional energy systems. In particular, the optimal design of energy systems gains importance, considering economic, environmental, and social factors. However, the design of energy systems requires many decisions that directly depend on system technology, its operating characteristics, and its disposal. Therefore, the sustainable use can only be ensured if the underlying dependencies throughout the entire life cycle are already considered in the design step. This work presents a computer-aided method for optimal energy system design that integrates operating characteristics (decisions on the control domain) into the design (decisions on the design domain). By integrating the cross-domain decision variables into one method, energy systems can be optimally designed. Design and operating characteristics (operational management and effects) are linked step by step in a dynamic simulation model using systematic process intensification. Air-to-water heat pump systems serve as a case study of themethod and represent an essential element for the electrification of the heat supply of existing buildings. Air-to-water heat pump systems are subject to dynamic boundary conditions during operation and exhibit operational effects (partial load behavior, operating envelope, thermal disinfection, and frosting of the evaporator), which are integrated into the design process. For design optimization, objective functions for economic efficiency (annualized cost) and environmental impacts (equivalent CO2-emissions) are chosen. For single-family houses in multiple scenarios, the method robustly designs optimal heat pump systems. The optimally designed heat pumpsystems maintain the required thermal comfort. To verify the design results, a refrigerant laboratory is being developed to study refrigerants, refrigeration cycles, heat pump systems, refrigeration cycle controllers, and system controllers. A hardware-in-the-loop flammable refrigerant environment is being developed to operate a propane heat pump. Corresponding experiments demonstrate interactions between design and operation and highlight the need for integrated design procedures. In summary, the developed method enables a cross-domain, optimal design, which, through abstraction ofrecommendations, pushes long-term sustainable use of energy in the building sector to protect the climate.


  • E.ON Energy Research Center [080052]
  • Chair of Energy Efficient Buildings and Indoor Climate [419510]