Hybrid personal cooling and heating system

Abstract

A fully adjustable hybrid personal cooling and heating system is configured to remove or supply heat from/to a human user. The system is specifically designed to provide up to 8-hours of high efficiency adjustable cooling or heating when worn and operated by a user. The personal cooling and heating system use non-toxic room-temperature liquid metal as primary coolant and phase-change material as secondary coolant. The primary coolant is pumped using an active powered pump which absorbs heat from the user's body, and passively release the heat to the secondary coolant making the invention a hybrid cooling/heating system. Passive heat release is facilitated by extreme high thermal conductivity of the primary coolant. Also, the secondary coolant is thermally insulated from the environment allowing on-demand heat absorption only from the primary coolant.

Claims

1. A hybrid personal cooling system, configured to remove heat from a human user; the personal cooling system comprising: a case comprising a pump having a pump suction and a pump discharge, the pump discharge is joined to a cooling tubing coil; wherein the case is a stainless-steel double-walled vacuum-insulated case; a pair of insulating caps, providing access to the case; a phase change material, inserted into the case through the pair of insulating caps and surrounding the cooling tubing coil within the case; a garment, comprising garment tubing having a garment tubing inlet and a garment tubing outlet; wherein the garment tubing inlet is joined to the cooling tubing coil with a first tube in an umbilical tube assembly; a maintenance cover, attached to the case between the pair of insulating caps, and joined to the umbilical tube assembly with an umbilical tube connector; a second tube in the umbilical tube assembly connecting the garment tubing outlet to the pump inlet; a dynamic fluid, comprising an alloy room-temperature liquid metal, wherein the dynamic fluid fills the cooling tubing and the garment tubing; a motor controller, electrically coupled to the pump; a thermocouple, operatively coupled to the garment tubing and communicatively coupled to the motor controller; wherein the motor controller is programmed with instructions to: receive a desired cooling temperature and humidity from the human user; while the pump is active execute the following loop of instructions; receive an actual temperature from the thermocouple; adjust a pump flow rate in the pump.

2. The personal cooling system of claim 1, wherein the liquid metal is a Gallium alloy of Gallium, Indium, and Tin.

3. The personal cooling system of claim 2, wherein the dynamic fluid further comprises approximately 90% by weight of the liquid metal and approximately 10% by weight one molar sodium hydroxide in order to reduce oxidation of the liquid metal.

4. The personal cooling system of claim 3, wherein the phase change material is at least one member of a phase change set consisting of: an organic phase change material selected from the organic phase change material set consisting of: paraffin and non-paraffin materials; an inorganic phase change material selected from the inorganic phase change material set consisting of: salt hydrate and metallic materials; and an Eutectic selected from the Eutectic set consisting of: organic-organic, inorganic-inorganic, organic-inorganic materials.

5. The personal cooling system of claim 4, wherein the dynamic fluid is formulated to release heat through conduction while passing through the cooling tubing coil surrounded by the phase change material while absorbing heat through conduction while passing through the second tube in order to remove heat from the human user.

6. A hybrid personal heating system, configured to add heat to a human user; the personal heating system comprising: a case comprising a pump having a pump suction and a pump discharge, the pump discharge is joined to heating tubing; wherein the case is a stainless-steel double-walled vacuum-insulated case; a pair of insulating caps, providing access to the case; a heater coil, surrounded by a phase change material within the case; wherein the heating tubing travels through the phase change material creating a personal heating system; an alternating current connector, electrically coupled to the heater coil; a garment comprising garment tubing having a garment tubing inlet and a garment tubing outlet; wherein the garment tubing inlet is joined to the heating tubing with a first tube in an umbilical tube assembly; a maintenance cover, attached to the case between the pair of insulating caps, and joined to the umbilical tube assembly with an umbilical tube connector; a second tube in the umbilical tube assembly connecting the garment tubing outlet to the pump inlet; a dynamic fluid, comprising an alloy room-temperature liquid metal, wherein the dynamic fluid fills the heating tubing and the garment tubing; a motor controller, electrically coupled to the pump; a thermocouple, operatively coupled to the garment tubing and communicatively coupled to the motor controller; wherein the motor controller is programmed with instructions to: receive a desired heating temperature and humidity from the human user; while the pump is active execute the following loop of instructions; receive an actual temperature from the thermocouple; adjust a pump flow rate in the pump.

7. The hybrid personal heating system in claim 6, wherein the liquid metal is a Gallium alloy of Gallium, Indium, and Tin.

8. The hybrid personal heating system in claim 6 wherein the dynamic fluid further comprises approximately 90% by weight of the liquid metal and approximately 10% by weight one molar sodium hydroxide in order to reduce oxidation of the liquid metal.

9. The hybrid personal heating system of claim 6, wherein the phase change material is wax, or molten salt.

10. The hybrid personal heating system of claim 6, wherein the dynamic fluid is formulated to absorb heat through conduction while passing through the heating tubing surrounded by the phase change material while releasing heat through conduction while passing through the second tube in order to transfer heat to the human user.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The detailed description of some embodiments of the invention is made below with reference to the accompanying figures, wherein like numerals represent corresponding parts of the figures.

(2) FIG. 1 shows a front perspective view of one embodiment of the present invention;

(3) FIG. 2 shows a front perspective view of one embodiment of the present invention;

(4) FIG. 3 shows a front elevation view of one embodiment of the present invention shown in use;

(5) FIG. 4 shows a front perspective view of one embodiment of the present invention; and

(6) FIG. 5 shows a schematic view of one embodiment of the present invention.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

(7) By way of example, and referring to FIGS. 1-5, one embodiment of a personal cooling system further comprises a hybrid liquid metal personal cooler 10. The hybrid liquid metal personal cooler 10 is joined to an umbilical tube 11 having an umbilical tube connector 11a through a thermally insulated maintenance access cover 1 lb.

(8) The hybrid liquid metal personal cooler 10 further comprises a stainless-steel double-walled vacuum-insulated case 12, attached to the umbilical tube connector 11a, a first insulating cap 14 and a second insulating cap 16. The umbilical tube 11 is joined to a cooling coil 16 which is used to cool a dynamic fluid in the cooling coil 16 in a cooling mode of operation.

(9) In some embodiments, the stainless-steel double-walled vacuum-insulated case 12 further comprises a phase change material 18. A heater coil 18 is now joined to an alternating current connector 18b such that comprises a stainless-steel double-walled vacuum-insulated case 12 now has a warming mode of operation.

(10) Embodiments of the disclosed invention can be used in clothing. For instance, vest 20 further comprises a vest front 20a joined to a vest rear 20b. The vest 20 is joined to a vest umbilical tube 21 having a vest umbilical tube connector 21a. In some embodiments the vest front 20a has a zipper 22.

(11) In some embodiments, the vest can have vest tubing 24 which carries a dynamic fluid through the vest 20. The vest tubing 24 is connected to the vest umbilical tube 21 with an outlet divider and an inlet divider 26.

(12) Turning to FIG. 5, the hybrid liquid metal personal cooler 10 further comprises a closed loop heat exchanger 30 as follows. A motor controller is electrically coupled to a pump. In some embodiments, the pump can be a peristaltic pump or centrifugal pump. The dynamic fluid exits the pump and then travels to a phase change material (PCM) creating a cool dynamic fluid. The cool dynamic fluid exits the heat exchanger 30 and travels to the vest 20 through the umbilical tubing as described above. This heats the cool dynamic fluid as heat is transferred from the user to the dynamic fluid creating a warm dynamic fluid. The warm dynamic fluid then travels into the pump intake.

(13) In some embodiments, a thermocouple is attached to the vest 20 in order to monitor the temperature of the user, the dynamic fluid or both. This temperature can be used to adjust the motor controller in order to control the temperature of the user. In some embodiments, the user enters a desired temperature and then the vest 20 is measured for that temperature at intervals controlled by a timer. The motor controller then adjusts a flow rate to calibrate the measured temperature to the desired temperature.

EXAMPLE

(14) In one example, the liquid-metal personal cooling system (PCS) can use Gallium alloy liquid-metal as the cooling medium. Liquid metal has a high thermal conductivity of 16.5 W/m.Math.K, which is 28 times higher than water. The high thermal conductivity of liquid metal is leveraged to develop an active PCS which combines the mobility of passive cooling with the long duration and controlled performance of active cooling. Here, cold liquid metal is pumped through tubing ( 3/32 inner diameter, 5/32 outer diameter, Tygon) in the interior of the garment. The liquid metal absorbs body heat and flows through a network of tubing submerged in a PCM cold pack. The warm liquid metal quickly cools in the PCM cold pack (a stainless-steel double-layer vacuum container) and recirculates. Unlike most commercial passive PCS, the PCM cold pack is isolated from the external environment using a thermally isolated container.

(15) The PCM container works as the cold pack for the hybrid cooling shirt. Circulating liquid metal cools down while passing through the cold pack. The container is designed to be manufactured using double-wall vacuum insulated stainless steel (1Cr18Ni9), which has corrosion resistance, high surface strength, and strong resistance to scouring in the presence of the liquid metal. Also, 1Cr18Ni9 stainless steel has a relatively low thermal conductivity, which is suitable for heat insulation of PCM. In addition, it is rust-resistant and does not react with PCM material. The PCM container has been designed in a rectangular shape for ease of carrying in a waist pouch bag. It has two thermal insulating caps giving access to its contents. These caps should be unscrewed when the cold pack is refilled or the PCM is cooled in a freezer. The PCM container has a double-wall vacuum-insulated detachable cover for liquid metal tube insertion and maintenance. A robust umbilical cord connects the container to the pump module and the cooling shirt. The dimensions of the container are designed to hold 4.2 lbs. of PCM designed to provide over 8 hours of cooling. Also, the PCM container increases the cooling efficiency of the PCM by 40% compared to passive PCS which uses PCM packs for cooling.

(16) Experiment

(17) The cooling performance of the active liquid-metal PCS along with a market-leading PCM passive cooling vest was tested and compared in the laboratory. The PCM cooling shirt was purchased from the Amazon. The experiment was carried out at 95 F. room temperature. First, a male-form mannequin was wrapped with PVC film (thermal conductivity of 0.19 W/m.Math.k) to raise the thermal conductivity of its surface to resemble human skin more closely. Second, the mannequin was dressed in either the liquid-metal PCS or the PCM cooling vest. Next, when the cooling systems were in operation, the surface temperature of the mannequin was measured until the temperature rose to 86 F. Both the liquid metal cooling shirt and PCM cooling vests used 4 lb. of PCM for cooling.

(18) Result

(19) The liquid-metal PCS was able to maintain cooling 40% longer than the commercial PCM cooling vest. During the experiment explained above the mannequin surface was cooled to a minimum of 70 F. The maximum measured temperature on the mannequin surface throughout 7 hours of operation was 86 F. The room temperature was 95 F., and the average mannequin surface temperature was 76.1 F. throughout the experiment. Thus, the liquid metal cooling system achieved an average difference between room temperature and the mannequin surface at 18.9 F. The average temperature of the cold liquid metal coming out from the PCM cold pack was 67.4 F., and the average temperature of liquid metal going into the PCM cold pack after cooling the mannequin was 82.6 F. The liquid-metal PCS prototype was able to provide an average of 50.27 watts of cooling for 7 hours with fully loaded weight only 9.25 lb.

(20) For personal heating application, the same primary coolant (liquid metal in 10% 1M NaOH) has been used and different secondary heating fluid is use such as hot wax, phase change material, or molten salt (FIG. 2). Also, an integrated heating coil heats the secondary heating medium when connected to a 110-240 AC outlet. Once heated and charged, the thermos is disconnected from the AC outlet and ready for use with the garment. Besides the heating coil, a thermally conductive tube network is installed inside the thermos, which carries the liquid metal (primary heating medium). The liquid metal is pumped through the tubing, which absorbs heat from the hot wax, phase change material, or molten salt. Now, the warm liquid metal is pumped through the tubing integrated into a garment (vest and/or trouser). While passing through the garment, the warm liquid metal releases heat and warm up the body of the wearer. After releasing the heat, the cold liquid metal is heated by passing it through the network of tubing embedded in the heat storage (wax, phase change material, or molten salt) inside the thermos (FIG. 1). The cycle continues when the warming system is in operation. The secondary heating medium, which acts as thermal storage, is insulated from the external environment, allowing heat transfer to only the cold liquid metal. It follows that the use of the liquid metal is critical for obtaining superior cooling.

(21) As used in this application, the term a or an means at least one or one or more.

(22) As used in this application, the term about or approximately refers to a range of values within plus or minus 10% of the specified number.

(23) As used in this application, the term substantially means that the actual value is within about 10% of the actual desired value, particularly within about 5% of the actual desired value and especially within about 1% of the actual desired value of any variable, element or limit set forth herein.

(24) All references throughout this application, for example patent documents including issued or granted patents or equivalents, patent application publications, and non-patent literature documents or other source material, are hereby incorporated by reference herein in their entireties, as though individually incorporated by reference, to the extent each reference is at least partially not inconsistent with the disclosure in the present application (for example, a reference that is partially inconsistent is incorporated by reference except for the partially inconsistent portion of the reference).

(25) A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.

(26) Any element in a claim that does not explicitly state means for performing a specified function, or step for performing a specified function, is not to be interpreted as a means or step clause as specified in 35 U.S.C. 112, 6. In particular, any use of step of in the claims is not intended to invoke the provision of 35 U.S.C. 112, 6.

(27) Persons of ordinary skill in the art may appreciate that numerous design configurations may be possible to enjoy the functional benefits of the inventive systems. Thus, given the wide variety of configurations and arrangements of embodiments of the present invention the scope of the invention is reflected by the breadth of the claims below rather than narrowed by the embodiments described above.