Overcoming system complexity: dynamic simulation of heat pump integration in paper drying
High-temperature heat pumps (HTHPs) are emerging as a key technology for industrial decarbonization and are particularly promising for steam-intensive processes such as paper drying. However, integrating HTHPs into existing steam networks remains challenging due to strong process dynamics, tight control requirements, and uncertainties regarding economic feasibility. This study investigates these aspects through a dynamic system simulation that couples a detailed drying-section model with a combined closed-loop compression heat pump (CLCHP) and mechanical vapor recompression (MVR) unit. The system generates 5.9 MW of steam at 5 bar using moist exhaust air at 86 °C as the heat source and achieves a global COP of 2.1. A techno-economic analysis (TEA) is performed for major European paper-producing countries, while particular emphasis is placed on evaluating transient behaviour and control strategies under disturbances such as rapid steam-demand reductions during paper breaks. Results demonstrate that while the HTHP is economically competitive under dynamic price scenarios, steady-state analysis alone is insufficient for assessing feasibility. Dynamic simulations reveal significant control challenges, including strong coupling between pressure and superheat regulation and the risk of compressor limit violations during paper breaks. A cascade-control strategy is shown to improve stability but still approaches operational boundaries. The findings highlight the necessity of dynamic simulation and control-oriented design in future industrial HTHP deployments and provide guidance on robust integration strategies for paper drying applications.