| Abstract |
Process heat represents a major share of industrial energy demand, often requiring steam at temperatures above 100°C. This demand is mainly met by fossil-fueled boilers, making it a primary target for decarbonization. High-temperature-heat-pumps (HTHPs) have been identified as a key technology for decarbonizing heat supply, with recent research focusing on steam-generating-heat-pumps (SGHPs) as a promising alternative for industrial steam supply. However, the industrial use of SGHPs is not yet widespread, partly due to a lack of reference systems. The aim of this study is to investigate the potential of a modified laboratory scale HTHP for steam supply, considering heat sources from medium depth geothermal energy. Experimental investigations are carried out on an existing 35 kW HTHP, which supplies 5 bar pressurized water up to 130°C and uses R1233zd(E) as a working fluid. The system is modified for indirect steam generation by adding a modular flash tank unit to the heat sink. This setup enables variable steam pressures and simplifies adaption of existing heat pump systems. As heat source a medium depth geothermal resource with a temperature of 60 °C is considered in the base case. In a first step, the system is analyzed for different operating points regarding steam quantities and pressures. Furthermore, the flexibility of the flash tank unit in terms of fluctuating steam demand is investigated. The results are applied in the context of a geothermal use case for a techno-economic analysis to support the implementation of HTHPs for industrial steam supply using renewable resources. |