15 May 2023

Presentation No 692 – Analysis of Large-Scale Ammonia Heat Pumps in Transient Operating Conditions – 14th IEA Heat Pump Conference, Chicago, USA

Large-scale ammonia heat pumps are a key technology for enabling sustainable heat supply. Exploiting
their potential in integrated systems requires the highest efficiencies and reliability even at varying operating
conditions. The varying operating conditions can result from variations in the heat source and sink, such as
variations in production processes and sudden changes of weather conditions. The dynamic operating conditions may result in unwanted dynamic effects, risking sub-optimal performance and component damage. This
study focuses on the development and validation of dynamic models for the components in an ammonia heat
pump system. The various components were assembled in a dynamic model implemented in Dymola and validated against test data from operation of a MW-scale ammonia heat pump. The system responses to sudden
changes in the source and sink conditions, compressor speed, and liquid levels in the system were studied. The
results from the validation showed that this dynamic model has great potential to be used for developing holistic control strategies and design guidelines in order to further improve the resilience and performance under
fluctuating boundary conditions for large-scale heat pumps.