Project Title:
Non-Azeotropic Spacecraft Cooling Systems
09.14-4942
Non-Azeotropic Spacecraft Cooling Systems
Frederick A. Costello Inc.
12864 Tewksbury Drive
Herndon
VA
22071
Costello
Frederick A.
NAS5-29439
Amount:
GSFC
NAS5-28643
Abstract:
We propose to design, build, ground test and flight test a small-scale, complete, working spacecraft temperature-control system that uses a non-azeotropic,
two-phase fluid as the working medium. The innovation lies in the use of the non-azeotropic
fluid. In Phase I we showed analytically that this novel system has great potential.
We resolved all of the previously identified problems. In addition, to resolve
the one potential problem that our analyses uncovered, we built a model of and ground
tested a complete system, not just the mixing section. This system will bring the
technology development to completion. All that will remain will be to implement
the concept in a full-scale application.
Non-azeotropic fluid mixture boils not at a fixed temperature but over a small range
in temperature (at a fixed pressure). Therefore, unlike conventional fluids, the
thermodynamic quality can be readily determined by sensing the easily measured temperature.
The following advantages result: simpler and more
reliable control systems; faster control system response; higher average evaporator
and condenser heat-transfer coefficients; smaller evaporators and condensers; reduced
fluid flow rates; lighter temperature-control systems, and less power practical means
for measuring quality. Quality sensors are heavy and costly and their response time
long. Instead, either the fluid is superheated and poor heat-transfer coefficients
are accepted or the platetemperature is measured and the control-system response
is long.