ESA Document - Emits - ESA

s
HMM
Assessment Study
Report: CDF-20(A)
February 2004
page 171 of 422
Europe has acquired these technologies through the Spacelab and Columbus programs (including
internal P/L like Biolab). These techniques can be qualified or mature and require tailoring to
low/moderate development to fit specific purposes.
Figure 3-33 shows an acquisition system within primary loop:
air 630 m3/hr
at 27C max
12.3 kW mean + 660W metabolic
cold plates
assembly
liquid/air HX
N
acquisition system
to thermal bus
(secondary loop)
13/18 C
liquid/liquid HX
1/6 C
thermostatic coils
(hull, propulsion, ...)
0 W worst case
Figure 3-33: Habitat module / primary loop principles
N
950 kg/hr
at 3.5b, 18C
pump assembly
accumulator
The acquisition system is integrated within a primary loop for which two cold thermal sinks are
available (second discrete temperature to cope with high peak dissipation). For certain units
requiring a smaller bandwidth, the degree of heat exchange is regulated by the selection of
adequate mass flow, such as in the liquid/air heat exchanger where one or two units in parallel
can be activated with selectable regulation of the flow for each.
Overall recuperated heat is transferred to the loop fluid that circulates inside bypass coils to
thermostatically control certain elements.
The same principles apply to the MAV and ERC main loops, connected to the thermal bus
through hydraulic connectors (two-way sealing by springs) at the interfaces.
3.3.3.4.3 Heat transport system
Characterization of the heat transport system can be outlined providing basic features of the fluid
loop and its working fluid:
• selection of a fluid loop depends mainly on the total power to transfer, the transport
distance, and the available working fluid
• selection of the working fluid depends on its thermodynamic, hydrodynamic and safety
performance (containment materials or man-related safety issues such as toxicity),