Valve-less Mechanically Pumped Fluid Loop (MPFL) using East and West Panels of a Large Telecommunication Satellite as Radiator



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45th International Conference on Environmental Systems


For a decade development of a 3-6kW single phase Mechanically Pumped Fluid Loop (MPFL) for active cooling of large telecommunication platforms such AlphaSat is initiated and supported by ESA up to and laboratory demonstration of a full scale loop and (partial) qualification of the loop components such as a pump, bypass valve, pressure transducers and accumulator. Until recently application of MPFL has been postponed by satellite builders because, the performance of conventional thermal solutions such as heat-pipe-networks could be extended to their limits. MPFL makes a more compact design of the satellite structure possible with the heat dissipating transceivers located on an internal structure instead of the conventional location on the side panels. Another option discussed in this paper for application in large geostationary satellites is to install it as a secondary cooling system without valve on the E/W panels. E/W panels are currently hardly used for cooling because parts of the orbit time they are exposed to solar flux that reduces their efficiency. Since the E/W radiators are not exposed to solar flux at the same time and will not become hotter than about +7oC, the E/W radiators are suitable for heat rejection. By arrangement of the payload loop in two sections in series with the East and West radiator a valve for controlling the flow is not needed. A mathematical model of this valve-less MPFL configuration is constructed to predict the thermal/hydraulic performance and orbital temperature stability. Transient thermal analysis and laboratory tests with a full scale loop showed that -without valve- orbital temperature stability of the payload is in the range of ±5.5oC, under variable load conditions. This can be improved by thermally crosslinking payload sections. A valve-less MPFL is therefore a recommended solution as (secondary) cooling system for large geostationary satellites allowing for more compact structural designs (or a higher power density), efficient use of the East/West radiator panels and improved system reliability.


Bellevue, Washington
Roel C. van Benthem, National Aerospace Laboratory, The Netherlands
Henk Jan van Gerner, National Aerospace Laboratory, The Netherlands
Johannes van Es, National Aerospace Laboratory, The Netherlands
Adry van Vliet, National Aerospace Laboratory, The Netherlands
Patrick van Put, Moog Bradford Engineering, The Netherlands
Jacques Elst, Moog Bradford Engineering, The Netherlands
David Schwaller, ESA/ESTEC, The Netherlands
The 45th International Conference on Environmental Systems was held in Bellevue, Washington, USA on 12 July 2015 through 16 July 2015.