Space suit body heat exchanger design composed of thermal conductance yarn and liquid coolant loop

Tucker, E. M.

English

NASA Technical Reports Server

SPACE SUIT HEAT  HANGER 
\ 
Sheet 1 of 2 Filed Oct. 2’7, 1967 ‘.t 
https://ntrs.nasa.gov/search.jsp?R=19710009964 2020-03-17T02:43:35+00:00Z
4 
SPACB SUIT HEAT EXCHANGER 
Filed O G t .  27, 1967 Sheet 2 of 2 
INVENTOR. 
3,425,487 
ACE SUIT HEAT EXCHANGER 
Eltau M. Tucker, La Porte, Tex., assignor to the United 
States of America as represented by the A ~ ~ i n ~ s t r a t o r  
~f the Natioanaf Aeronautics and Space Administration 
Piled Oct. 27, 1967, Ser. No. 678,700 
U.S. a. 165-46 7 Claims 
Ink el. F28f 7/00; A61f 7/00; F25d 3/08 
A body heat exchanger for usage with space suits, the 
purpose of which is to transfer thermal energy to or 
away from the body surface of the wearer. The heat 
exchanger is a very fine grid of small, flexible, high 
thermal conductance yarn in intimate contact with the 
body, which serves to transfer heat from the body sur- 
face into a liquid coolant loop, included as a portion of the 
assembly, through which circulates a fluid of a desired 
temperature. 
The invention described herein was made by an em- 
ployee of the United States Government and may be 
manufactured and used by or for the Government for 
governmental purposes without the payment of any royal- 
ties thereon or therefor. 
Background of the invention 
The present invention relates to a heat exchanger par- 
ticularly suitable for integration into a garment designed 
to maintain a desirable thermal balance of the wearer. 
One major problem of manned space flight is the proper 
thermal control of the crewman during intravehicular and 
extravehicular missions. Heat generated metabolically and 
also from the external environment must be removed from 
the crewman's environment in order to protect him from 
excess thermal loads. 
Existing cooling assemblies utilize a cooled gaseous 
flow within the space suit to provide for evaporative 
cooling of lbody-generated heat. Protection from external 
heat is achieved through the use of combinations of con- 
ductive and radiation insulations. The problems attendant 
with these designs are numerous. The cooling effect is not 
adequate to prevent thermal discomfort, particularly of 
the hands and feet, because of the lack of direct cooling 
flow for these areas. The hands tend to become wet with 
perspiration, which promotes discomfort and inefficiency. 
Convective cooling in these areas is difficult to obtain, 
due to the mobility requirements of the hands. 
An alternate arrangement is to provide the garment 
with small diameter tubing, extensive throughout the suit, 
through which circulates a cooling fluid. The tubing is 
highly concentrated in a parallel arrangement over the 
lbody, therefore requiring a large amount of tubing (over 
200 feet) and large power requirements to pump the fluid 
through the tubing. Again, there is no feasible means to 
provide direct thermal control of the hands, fingers, and 
feet, and simultaneously provide for flexibility and low 
bulk when using this alternate arrangement. Furthermore, 
the heat dissipation will be concentrated in the immediate 
vicinity of the tubing, thus limiting the temperature ex- 
tremes at which the coolant can circulate and still pro- 
vide comfort to the crewman. 
Summary 
The instant invention provides a very fine grid of small, 
high thermal conductance yarn in intimate contact with 
the skin of the wearer. The grid assembly serves to trans- 
fer heat into or away from a heat sink assembly incor- 
porating a circulating fluid of a controlled temperature. 
In the trunk, arm, and leg sections of the thermal garment, 
the heat sink is in the form of a flexible coolant duct 
thermally connected to the grid section covering those 
portions of the body. In the glove and boot components 
of the suit, the heat sink is in the form of a heat exchanger 
5 cuff, a wristlet, or anklet, thermally connected to the grid 
section covering the particular extermity. In all cases, the 
grid is coextensive so as to cover the body, including 
selected portions of the head if so desired. The coolant 
duct is located strategically about the trunk, arms, and 
legs, so as to minimize the amount of tubing necessary, 
the thermal conductance of the grid primarily being relied 
on to effect the heat transfer from the surface of the skin. 
The advantages of this assembly are obvious. Thermal 
control of the torso and the extremities, particularly the 
15 hands and fingers, is effectuated with reduced external 
insulation and its attendant 'bulk and with wbstantial im- 
provements in wear comfort. The glove can be made more 
flexible and can provide the wearer with increased tactility 
and mobility as required for pressure suit operations. 
20 Perspiring is minimized as compared with systems utiliz- 
ing gaseous flow. Less tubing is required than systems 
relying solely on tubing without the thermal grid assembly. 
All this adds up to a lightweight, comfortable, flexibble, 
highly efficient space suit heat exchanger for control of 
It should be noted that the instant invention has u t ika-  
tion in applications other than space activities. Thermal 
protection is affordable by means of this heat exchanger, 
as an undergarment, to anyone working in extreme hot 
30 or cold environments. This assembly could easily be 
adapted for use in underwater missions. The glove com- 
ponent, as a separate item, could be used by laboratory 
and industrial personnel required to handle very hot or 
cold items for extended periods of time. The advantages 
35 of the heat exchanger in such non-space utilizations cor- 
respond with use in space. 
Although the invention is particularly pointed out in 
the appended claims, the invention itself will be better 
understood by referring to the following description of a 
40 preferred embodiment taken in connection with the ac- 
companying drawings in which like numerals identify like 
parts and in which: 
Brief description of the drawings 
25 body skin surface temperature. 
45 FIG. 1 is a perspective schematic view of body heat 
FIG. 2 is an enlarged view of the glove component of 
FIG. 3 is an enlarged view of the boot component of 
exchanger as disclosed herein. 
FIG. 1. 
50 FIG. 1. 
FIG. 4 is a perspective detail of the junction of the 
FIG. 5 is a perspective end view of FIG. 4, showing 
FIG. 6 is a perspective detail of an alternate thermal 
grid and the coolant dwt. 
an assembly detail. 
junction of the grid assembly and the coolant duct. 
55 
Description of the preferred embodiment 
FIG. 1, FIG. 2, and WG. 3 schematically illustrate 
60 the heat exchanger assembly 10 of a space suit system. 
This system is designed to be in contact with the skin 
of the wearer, either directly or in very close proximity, 
perhaps through a thin layer of fabric designed to  im- 
prove comfort of the assembly. As such, the heat ex- 
65 changer assembly is used as an undergarment within 
the space suit. 
Liquid carrying coolant duct 12 is located strategically 
so as to provide a localized heat sink for the torso, arm, 
and leg portions of the heat exchanger assemlbly 10 as 
70 shown in FIG. 1. The coolant duct 12 also conducts the 
liquid through ,wristlet and anklet heat sinks 14 and 16, 
respectively, which will be described below. The duct 
3,425,481 
12 carries liquid, such as ter, at a low temperature, 
supplied by the life support system, entering the waist 
manifold 17 at inlet 18, flowing throughout the system, 
and leaving through outlet 20. Supply and exhaust lines 
22 and 24, respectively, are attached to the waist mani- 
fold 17 at inlet 18 and outlet 20 by any \well-known 
quick-disconnect means, not shown. The duct is of a 
flexible material, such as polyethylene or polyvinyl- 
chloride. The design is such as to place reliance on the 
grid structure to transfer the majority of the heat, rather 
than on the more localized duct. This allows the fluid 
to circulate at a lower temperature than in systems rely- 
ing on coolant tubing solely, since there is less concen- 
tration of heat transfer and more even heat dissipation 
with the grid assembly. The overall effect is increased 
efficiency and comfort. 
The grid structure 26 consists of small, high thermal 
conductance yarn fabricated from strands of silver, cop- 
per, or such, in a loose-knit weave. 
The torso, arm, and leg components of the heat ex- 
changer assembly comprise heat sink coolant duct 12 
thermally connected to grid 26, which grid is coextensive 
so as to cover the entire body of the crewman. As pre- 
viously described, duct 2 is arranged strategically a’bout 
the body such as shown in FIG. 1, so as to effect an 
efficient, uniform heat transfer from the skin through 
conductance grid 26, and into the coolant circlulating 
through duct 12. 
The grid portion in contact with d-uct 12 is best shown 
in FIGS. 4 and 5. The part of the grid weave, which 
is transverse to the duct, passes through the duct at its 
diameter. In this manner, heat transfer is effected from 
the grid directly into the coolant flowing through the 
duct. Duct 12 may be molded directly on the grid 26; 
it may be split longitudinally and cemented together with 
the grid at the interface, or assembled in some other 
suitable fashion, such as in FIG. 6, wherein the grid is 
woven about coolant duct 12. 
The. glove and boot components of the heat exchanger 
assembly are best depicted in FIGS. 2 and 3, respectively. 
Because of the high degree of flexibility and lack of bulk 
required of these components, the basic structure varies 
somewhat from that of the torso, arm, and leg compo- 
nents. Duct 12 terminates and is in communication with 
liquid coolant loop 28 in wristlet 14, and with a corre- 
sponding liquid coolant loop 30 in anklet 16. Wristlet 14 
and anklet 16 at the extremities of assembly 10 serve as 
heat sinks for the glove component and the boot com- 
ponent, respectively, which components are readily de- 
tachable from the extremity of the assembly by means 
of any well-known quick-disconnect means, not shown. 
A thermally conductive material, such as copper, is 
chosen for the wristlet and the anklet. On the glove and 
boot members, at the portion which is adapted to be 
connected to the extremity of the assembly at the wristlet 
and anklet, are corresponding thermally-conductive cop- 
per rings 36 and 38, respectively, which thermally con- 
tact the wristlet and anklet through the quick-disconnect 
means at 32 and 34. The advantage in this partimlar 
stnucture can be readily understood. It would be ex- 
tremely difficult to have coolant flow through the glove 
and boot components themselves, because of the attend- 
ant bulk and the difficulty in valving the coolant through 
the quick-disconnect means of the glove and boot when 
such components are removed from the space suit. The 
instant arrangement allows the coolant to  flow through 
the wristlet and ankle of the main body portion of the 
suit, the heat transfer being effected by conduction through 
the rings 36 and 38 and the quick disconnect means. The 
thermal grid assembly of the glove and boot components, 
included as a separate inner glove or  sock, or as an 
integrated assembly with the boot and glove, is ther- 
mally joined to rings 36 and 38 such as by silver soldering 
the longitudinal portions at the points of contact cir- 
cumferentially about the rings. Thus, with the glove or 
boot connected to the assembly, thermal energy will flow 
by conductance from the skin through the grid which 
encompasses the extremity, to conductive ring 36 or 38, 
through the quick-disconnect means, through wristlet 14 
or anklet 16, and iuto the liquid circulating through cool- 
ant loop 28 or 30 within wristlet 14 or anklet 16, re- 
spectively. This particular structure enables the glove 
and boot components to be extremely flexible, free of 
excess ,bulk, and quickly removable. Coolant tubing is 
localized in the wristlet and anklet and not in the glove 
or boot itself. Direct passive thermal control of the 
hands, fingers, and feet is accomplished in a comfortable, 
feasible way. 
Other embodiments of the space suit heat exchanger 
15 might include an absorbent fabric interwoven into the 
thermally conductive grid for the purpose of absorbing 
perspiration. For industrial purposes where only the glove 
component may be used, the quick-disconnect means can 
be eliminated, the tubing carrying fluid directly to a cool- 
20 and loop in thermally conductive ring to which the grid 
portion is attached. 
As to utilization of the heat exchanger assembly with 
the space suit, it is noted that the grid may be separate 
and positioned either inside or outside the usual gas 
25 bladder. It may also be impregnated with the bladder 
elastomer, thus becoming an integral part thereof. 
The life support system (not shown) is conventional, 
and supplies the coolant fluid to circulate through the 
assembly. 
Thus, it will be seen that a garment heat exchanger 
assembly is disclosed which will greatly enhance the 
comfort of the crewman, increase overall mobility for 
extended periods of wear, and increase the efficiency of 
heat exchange in appropriate applications. 
Although a particular embodiment of the subject in- 
vention has been illustrated and described in order to ex- 
plain the invention, it will be understood that various 
changes and modifications may be made by those skilled 
in the art, yet remain within the principle and scope of 
What is claimed and desired to be secured by Letters 
I. A heat exchanger adapted to maintain body tempera- 
continuous duct means for circulating a fluid to the 
various body portions of the person; 
continuous, conductive grid means comprising inter- 
woven threads of solid material thermally connected 
to said duct means and depending therefrom in close 
proximity to the skin of a person and extensive 
about the body portions so as to substantially 
conform to the shape of the person, said grid means 
adapted to conductively exchange thermal energy 
between the skin of the lperson and the duct means; 
means allowing ingress and egress of the fluid to and 
from said duct means. 
2. The heat exchange assembly of claim 1 wherein 
said duct means is of a flexible material, and said thermal 
60 connection of said grid means and said duct means com- 
prises a portion of the grid means woven about the duct 
means for effecting heat transfer from the skin of the 
person to the circulating fluid. 
3. The heat exchange assembly of claim 1 wherein said 
66 duct means is of a flexible material, and said thermal 
connection of said grid means and said duct means com- 
prises a portion of the grid means intersecting the duct 
means for effecting heat transfer directly between the 
grid and said fluid circulating in said duct means. 
4. The heat exchange assembly of claim 3 wherein 
said duct means is molded directly onto said grid means. 
5. An extremity heat exchange assembly for maintain- 
ing an extremity of a person within a predetermined 
30 
35 
40 the invention as expressed in the appended claims. 
Patent is: 
ture within a predetermined range comprising: 
45 
50 
55 and 
75 range comprising: 
3,425,487 
continuous duct means for circulating a fluid to the 
various body portions of the person; 
a continuous conductive grid means comprising inter- 
woven threads of solid material thermally connected 
to said duct means and depending therefrom in close 
proximity to the skin of the extremity of the person 
and coextensive thereabout so as to substantially 
conform to the shape of the extremity, said grid 
means adapted to conductively exchange thermal 
energy between the skin on the extremity of the 
person and the duct means; and 
means allowing ingress and egress of the fluid to and 
from said duct means. 
6.  An extremity heat exchange assembly for maintain- 
ing an extremity of a person within a predetermined range 
comprising : 
an annular ring of a thermally conductive material 
through which flows a fluid; 
a continuous conductive grid means comprising inter- 
woven threads of a solid material thermally con- 
nected circumferentially about said ring and depend- 
ing therefrom in close proximity to the skin of the 
extremity of the person and coextensive thereabout 
so as to substantially conform to the shape of the 
extremity, said grid means adapted to conductively 
exchange thermal ene 
extremity of the person and the ring; and 
from said ring. 
between the skin on the 
means allowing ingress and egress of the fluid to and 
7. The extremity heat exchange assembly of claim 
wherein said ring is comprised of two quickly detac 
able sections, the first of said sections, through which 
flows said fluid, being integral with a suit heat exchange 
assembly, and the second of said sections being a cuff 
means to which said grid is attached by said thermal con- 
nection. 
eferences Citedl 
341,584 5/1886 Leiter _ _ _ _ _ _ _ _ _ _ _ _ _ _  165-46 
l5 382,681 5/1888 Batter _ _ _ _ _ _ _ _ _ _  126-204 XR 
586,998 7/1897 Harmer _ _ _ _ _ _ _ _ _  165-46 XR 
3,289,748 12/1966 Jennings _ _ _ _ _ _ _ _ _ _ _ _  165-46 
3,295,594 1/1967 Hopper _ _ _ _ _ _ _ _ _ _ _ _ _ _  165-46 
UNITED STATES PATENTS 
2o FRED C. MATTERN, JR., Priinary Examiner. 
M. ANTONAKAS, Assistant Examliner. 
U.S. c1. X.R. 
25 62-530; 126-204 


Space suit heat exchanger Patent

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