15 May 2023

Presentation No 787 – Ammonia – Steam cascade heat pump for +100˚C steam generation – 14th IEA Heat Pump Conference, Chicago, USA

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A new innovative high temperature heat pump solution developed by GEA, ANEO and EPCON is presented in this paper:
High efficiency and high temperature heat pump for generating steam in the processing industry. By using natural
refrigerants ammonia and steam it is possible to ensure the highest possible efficiency without causing any potential
harmful damage to the global environment. The heat pump harnesses the heat from the exhaust moist air from the drying
process, the air is cooled and dehumidified. It is important to dehumidify the air as a substantial amount of energy is latent
energy in the moist exhaust air. Chilled water as low as 20 °C is needed for the energy extraction and a 2-stage ammonia
heat pump is used as the first step to generate 85 – 90 °C steam. The dry steam is then compressed to the required steam
pressure of 2 bar (around 120 °C) with 4 centrifugal fans in series. This multistage cascade solution gives a high efficiency
and minimize the cost by combining two technologies (steam compression and ammonia compression) each operating in
the application area where they are the best available technology and hereby achieving a temperature lift of 100K with a
heating COP of 3.1.