1992-07-01

Ammonia Boiler Concepts for Hermes ATCS - Water Loop 921207

Evaporative heat sinks are used for space vehicles which perform autonomous reentry. They profit of the latent heat of evaporation to reject expendable heat in form of the vapour flow of the evaporation fluid into the environment.
The Ammonia Boiler Assembly of HERMES Spaceplane is such an evaporative heat sink. Ammonia from dedicated storage devices is evaporated cooling the water of the closed ATCS water loop.
Due to operation at different thermal loads and different ambient pressures, the evaporation process
runs at different saturation conditions: The evaporation temperature varies between -33 °C and +5 °C. Potential freezing in the water loop according to the different mission phases with + 6 °C or 8 °C outlet temperatures is avoided using a special routing of the two fluids, water and ammonia, within the evaporator, by application of a special heat exchanger design and the selection of a two stage concept.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 43% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.
X