# US 12,119,465 B2 · Heat exchanger assemblies and cooling systems for evtol aircraft > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,119,465 B2 - Document ID: US12119465B2 - Status: Granted - Kind: B2 - Application number: 18/460,463 - Filed: 2023-09-01 - Published: 2024-05-16 - Granted: 2024-10-15 - Earliest claimed: 2022-11-14 - Assignees: Archer Aviation Inc. - Applicants: Archer Aviation, Inc. - Inventors: Bharat Tulsyan; Weiyu Cao; Pablo Ramaswamy; Ryan Cherniak; Alex Clarabut - Web page: https://patentgrep.com/patent/US12119465B2 ## CPC - H01M 10/613: Cooling or keeping cold - B60L 3/04: Cutting off the power supply under fault conditions (protective devices and circuit arrangements in general H01H; H02H) - B60L 50/60: using power supplied by batteries (in combination with fuel cells B60L50/75) - B60L 58/26: by cooling - B64C 3/32: specially adapted for mounting power plant - B64D 27/31: within, or attached to, wings - B64D 27/34: All-electric aircraft - B64D 27/357: using batteries - B64D 33/08: of power plant cooling systems - B64D 35/021: for electric power plants - F28F 3/04: the means being integral with the element - F28F 3/044: {the deformations being pontual, e.g. dimples} - F28F 3/12: Elements constructed in the shape of a hollow panel, e.g. with channels {(F28D1/02, F28D1/03 take precedence)} - H01M 10/425: {Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing (printed circuits H05K1/00)} - H01M 10/482: {for several batteries or cells simultaneously or sequentially} - H01M 10/486: {for measuring temperature} - H01M 10/625: Vehicles - H01M 10/6554: Rods or plates - H01M 10/6556: Solid parts with flow channel passages or pipes for heat exchange (closed pipes H01M10/6552) - H01M 10/6568: characterised by flow circuits, e.g. loops, located externally to the cells or cell casings - H01M 50/204: Racks, modules or packs for multiple batteries or multiple cells - H01M 50/249: specially adapted for aircraft or vehicles, e.g. cars or trains (constructional details of batteries specially adapted for electric vehicles B60L50/64) - H01M 50/502: Interconnectors for connecting terminals of adjacent batteries; Interconnectors for connecting cells outside a battery casing - H01M 50/583: in response to current, e.g. fuses - H02H 7/20: for electronic equipment (for converters H02H7/10; for electric measuring instruments G01R1/36; for DC voltage or current semiconductor regulators G05F1/569; for amplifiers H03F1/52; for electronic switching circuits H03K17/08) - H02J 7/82: Control of state of charge [SOC] - B60L 2200/10: Air crafts - B64C 29/0008: {having its flight directional axis horizontal when grounded} - B64C 29/0033: {the propellers being tiltable relative to the fuselage} - F28D 1/03: with plate-like or laminated conduits {(stacked plates having one or more openings therein to form tubular heat-exchange passages F28F3/086)} - F28D 2021/0021: {for aircrafts or cosmonautics} - F28D 2021/0029: {Heat sinks} - H01M 2010/4271: {Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing} - H01M 2200/103: Fuse - H01M 2220/20: Batteries in motive systems, e.g. vehicle, ship, plane - H02G 3/08: Distribution boxes; Connection or junction boxes - H02J 2105/32: {for aircrafts} - Y02E 60/10: Energy storage using batteries - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - B64C: AEROPLANES; HELICOPTERS - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general) - H02G: INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A cooling system includes a plurality of heat exchanger assemblies corresponding to a plurality of battery packs and a fluid conveyance assembly. Each heat exchanger assembly includes a first heat exchanger inlet-outlet and a second heat exchanger inlet-outlet configured to receive a heat transfer fluid or discharge the heat transfer fluid. The fluid conveyance assembly is coupled to the heat exchanger assemblies and configured to circulate the heat transfer fluid in parallel to the heat exchanger assemblies in a U-flow scheme with an inlet and an outlet of the heat transfer fluid arranged at the same location. The fluid conveyance assembly includes a plurality of flow restrictors configured to balance the heat transfer fluid flowing into the heat exchanger assemblies. The heat transfer fluid flows through the corresponding flow restrictor before flowing into the corresponding heat exchanger assembly of the battery pack. ## Claims ### Claim 1 A cooling system for an electric aircraft, comprising: a plurality of heat exchanger assemblies corresponding to a plurality of battery packs of the electric aircraft, each heat exchanger assembly comprising a first heat exchanger inlet-outlet and a second heat exchanger inlet-outlet configured to receive a heat transfer fluid or discharge the heat transfer fluid; and a fluid conveyance assembly coupled to the heat exchanger assemblies and comprising a first main inlet-outlet and a second main inlet-outlet, and configured to circulate the heat transfer fluid in parallel to the heat exchanger assemblies, the first main inlet-outlet and a second main inlet-outlet being arranged at a same location of the electric aircraft, the fluid conveyance assembly further comprising: a plurality of conduit segments configured to passively balance the heat transfer fluid flowing into each of the heat exchanger assemblies, wherein each heat exchanger assembly comprises a heat exchanger plate configured to receive the heat transfer fluid from the first heat exchanger inlet-outlet and discharge the heat transfer fluid to the second heat exchanger inlet-outlet in a first operating period, and to receive the heat transfer fluid from the second heat exchanger inlet-outlet and discharge the heat transfer fluid to the first heat exchanger inlet-outlet in a second operating period before or after the first operating period. ### Claim 2 (depends on 1) The cooling system of claim 1, wherein the plurality of conduit segments comprises a plurality of fixed flow restrictors configured to balance the heat transfer fluid flowing into each of the heat exchanger assemblies. ### Claim 3 (depends on 2) The cooling system of claim 2, wherein each of the plurality of fixed flow restrictors comprises a sizing orifice configured to ensure an equal inlet pressure at each heat exchanger assembly to achieve an even flow distribution of the heat transfer fluid. ### Claim 4 (depends on 1) The cooling system of claim 1, wherein each of the plurality of conduit segments comprises a different inside diameter configured to balance the heat transfer fluid flowing into each of the plurality of heat exchanger assemblies. ### Claim 5 (depends on 1) The cooling system of claim 1, wherein each heat exchanger plate further comprises: a first manifold channel coupled to the first heat exchanger inlet-outlet; and a second manifold channel coupled to the second heat exchanger inlet-outlet. ### Claim 6 (depends on 5) The cooling system of claim 5, further comprising: a plurality of cooling channels coupled between the first manifold channel and the second manifold channel and arranged to allow the heat transfer fluid to flow through the cooling channels, wherein each cooling channel comprises a plurality of dimples configured to provide a turbulating flow of the heat transfer fluid through the cooling channel, each of the plurality of dimples comprising a symmetric geometry. ### Claim 7 (depends on 6) The cooling system of claim 6, wherein the symmetric geometry comprises a first flat, forward-sloped face as viewed in a first flow direction of the heat transfer fluid, and a second flat, forward-sloped face as viewed in a second flow direction of the heat transfer fluid opposite the first flow direction. ### Claim 8 (depends on 6) The cooling system of claim 6, wherein the symmetric geometry comprises one of a triangular shape or a trapezoidal shape. ### Claim 9 (depends on 6) The cooling system of claim 6, wherein the heat exchanger plate is configured to organize the plurality of cooling channels into a plurality of cooling units, and the plurality of cooling units are coupled in parallel between the first manifold channel and the second manifold channel. ### Claim 10 (depends on 1) The cooling system of claim 1, wherein the heat exchanger plate comprises aluminum. ### Claim 11 (depends on 6) The cooling system of claim 6, wherein the plurality of dimples in each cooling channel are arranged in a staggered manner such that adjacent dimples in a flow direction are extended from opposite sides of the cooling channels. ### Claim 12 (depends on 11) The cooling system of claim 11, wherein the adjacent dimples in the flow direction are indented from laterally opposite sides of top or bottom surfaces of the cooling channels. ### Claim 13 (depends on 11) The cooling system of claim 11, wherein the adjacent dimples in the flow direction are indented from laterally opposite side surfaces of the cooling channels. ### Claim 14 (depends on 1) The cooling system of claim 1, wherein the heat transfer fluid comprises ethylene glycol water (EGW), ethylene glycol, polyethylene glycol, water, or any combinations thereof. ### Claim 15 (depends on 1) The cooling system of claim 1, wherein the plurality of conduit segments of the fluid conveyance assembly further comprises: a first tube and a plurality of first hoses coupled to the first tube; and a second tube and a plurality of second hoses coupled to the second tube. ### Claim 16 (depends on 15) The cooling system of claim 15, wherein the first tube comprises a first trunk path leading from the first main inlet-outlet, and the plurality of first hoses comprises a first branch coupled to the first trunk path; and the second tube comprises a second trunk path leading from the second main inlet-outlet, and the plurality of second hoses comprises a second branch coupled to the second trunk path. ### Claim 17 (depends on 16) The cooling system of claim 16, wherein a plurality of fixed flow restrictors are coupled to the first hoses or the second hoses. ### Claim 18 (depends on 15) The cooling system of claim 15, wherein the first tube and the second tube comprise aluminum. ### Claim 19 (depends on 1) The cooling system of claim 1, wherein the first main inlet-outlet and the second main inlet-outlet are located at a top side of the electric aircraft. ### Claim 20 (depends on 1) The cooling system of claim 1, wherein the fluid conveyance assembly further comprises: a first trunk path leading from the first main inlet-outlet to a first branch and third branch; and a second trunk path leading from the second main inlet-outlet to a second branch and fourth branch, wherein the first trunk path and the second trunk path are equal in length. ### Claim 21 (depends on 20) The cooling system of claim 20, wherein the first main inlet-outlet and the second main inlet-outlet are located closer to the first branch than to the second branch. ### Claim 22 A method for battery cooling, comprising: circulating, by a fluid conveyance assembly, a heat transfer fluid to a plurality of heat exchanger assemblies corresponding to a plurality of battery packs included in an electric aircraft, wherein each heat exchanger assembly comprises a first heat exchanger inlet-outlet and a second heat exchanger inlet-outlet configured to receive or discharge the heat transfer fluid, and a heat exchanger plate; and providing a turbulating flow of the heat transfer fluid through cooling channels of the heat exchanger plate by a plurality of dimples, wherein the plurality of dimples in the cooling channels are arranged in a staggered manner such that adjacent dimples in a flow direction of the cooling channels are extended from opposite sides of the cooling channel; wherein operations of circulating the heat transfer fluid comprise; in a first operating period, receiving the heat transfer fluid from the first heat exchanger inlet-outlet and discharging the heat transfer fluid to the second heat exchanger inlet-outlet; and in a second operating period, receiving the heat transfer fluid from the second heat exchanger inlet-outlet and discharging the heat transfer fluid to the first heat exchanger inlet-outlet. ### Claim 23 A power supply system for an aircraft, comprising: a plurality of battery packs configured to be installed within a wing portion of the aircraft, wherein each battery pack is configured to be connected to an electric engine of the aircraft to provide power; a plurality of heat exchanger assemblies corresponding to the plurality of battery packs of the aircraft, each heat exchanger assembly comprising a first heat exchanger inlet-outlet and a second heat exchanger inlet-outlet configured to receive a heat transfer fluid or discharge the heat transfer fluid; and a fluid conveyance assembly coupled to the heat exchanger assemblies and comprising a first main inlet-outlet and a second main inlet-outlet, and configured to circulate the heat transfer fluid in parallel to the heat exchanger assemblies, the first main inlet-outlet and a second main inlet-outlet being arranged at a same location of the aircraft, the fluid conveyance assembly further comprising: a plurality of conduit segments configured to passively balance the heat transfer fluid flowing into each of the heat exchanger assemblies, wherein each heat exchanger assembly comprises a heat exchanger plate configured to receive the heat transfer fluid from the first heat exchanger inlet-outlet and discharge the heat transfer fluid to the second heat exchanger inlet-outlet in a first operating period, and to receive the heat transfer fluid from the second heat exchanger inlet-outlet and discharge the heat transfer fluid to the first heat exchanger inlet-outlet in a second operating period before or after the first operating period. ### Claim 24 A power supply system for an aircraft, comprising: a plurality of battery packs configured to be installed within a wing portion of the aircraft, wherein each battery pack is configured to be connected to an electric engine of the aircraft to provide power; a plurality of heat exchanger assemblies respectively connected to battery pack enclosures of the plurality of battery packs, each heat exchanger assembly comprising a cooling channel; and a fluid conveyance assembly coupled to the plurality of heat exchanger assemblies and configured to circulate a heat transfer fluid through the cooling channels in the heat exchanger assemblies; wherein each cooling channel comprises a plurality of dimples arranged in a staggered manner such that adjacent dimples in a flow direction of the cooling channels are extended from opposite sides of the cooling channels; and wherein the adjacent dimples in the flow direction are partially indented from laterally opposite sides of top or bottom surfaces of the cooling channels such that a first height of the cooling channels in a region not having a dimple is greater than a second height of the cooling channels in a region having a dimple. ### Claim 25 (depends on 24) The power supply system of claim 24, wherein the adjacent dimples in the flow direction are indented from laterally opposite side surfaces of the cooling channels. ### Claim 26 (depends on 24) The power supply system of claim 24, wherein each of the plurality of dimples comprises a symmetric geometry having a flat, forward-sloped face as viewed in the flow direction. ### Claim 27 (depends on 26) The power supply system of claim 26, wherein the dimples comprise a second flat, forward-sloped face as viewed in a direction opposite the flow direction. ### Claim 28 (depends on 24) The power supply system of claim 24, wherein the dimples comprise a triangular or trapezoidal shape. ### Claim 29 (depends on 22) The method of claim 22, wherein the adjacent dimples in the flow direction are indented from laterally opposite sides of top or bottom surfaces of the cooling channels. ### Claim 30 (depends on 22) The method of claim 22, wherein the adjacent dimples in the flow direction are partially indented from laterally opposite sides of top or bottom surfaces of the cooling channels. ### Claim 31 (depends on 22) The method of claim 22, wherein the adjacent dimples in the flow direction are indented from laterally opposite side surfaces of the cooling channels. ### Claim 32 (depends on 22) The method of claim 22, wherein each of the plurality of dimples comprises a symmetric geometry having a first flat, forward-sloped face as viewed in a first flow direction of the heat transfer fluid, and a second flat, forward-sloped face as viewed in a second flow direction of the heat transfer fluid opposite the first flow direction. ### Claim 33 (depends on 22) The method of claim 22, further comprising: balancing, by a plurality of flow restrictors of the fluid conveyance assembly, the heat transfer fluid flowing into the heat exchanger assemblies. ### Claim 34 (depends on 33) The method of claim 33, wherein balancing the heat transfer fluid flowing into the heat exchanger assemblies comprises: ensuring, by using sizing orifices, a equal inlet pressure at each heat exchanger assembly for an even flow distribution of the heat transfer fluid. ### Claim 35 (depends on 22) The method of claim 22, further comprising: balancing, by a plurality of differently sized conduit segments of the fluid conveyance assembly, the heat transfer fluid flowing into the heat exchanger assemblies. ### Claim 36 (depends on 22) The method of claim 22, wherein the heat transfer fluid comprises ethylene glycol water (EGW), ethylene glycol, polyethylene glycol, water, or any combinations thereof. ### Claim 37 (depends on 22) The method of claim 22, wherein the dimples comprise a triangular or trapezoidal shape. ### Claim 38 (depends on 24) The power supply system of claim 24, wherein the fluid conveyance assembly comprises: a first main inlet-outlet; a second main inlet-outlet; and a plurality of conduit segments configured to passively balance the heat transfer fluid flowing into each of the heat exchanger assemblies, wherein the first main inlet-outlet and a second main inlet-outlet are arranged at a same location of the electric aircraft. ### Claim 39 (depends on 38) The power supply system of claim 38, wherein the plurality of conduit segments comprises a plurality of fixed flow restrictors configured to balance the heat transfer fluid flowing into each of the heat exchanger assemblies. ### Claim 40 (depends on 39) The power supply system of claim 39, wherein each of the plurality of fixed flow restrictors comprises a sizing orifice configured to ensure an equal inlet pressure at each heat exchanger assembly to achieve an even flow distribution of the heat transfer fluid. ### Claim 41 (depends on 38) The power supply system of claim 38, wherein each of the plurality of conduit segments comprises a different inside diameter configured to balance the heat transfer fluid flowing into each of the plurality of heat exchanger assemblies. ### Claim 42 (depends on 24) The power supply system of claim 24, wherein each heat exchanger assembly further comprises: a heat exchanger plate, comprising: a first manifold channel coupled to a first heat exchanger inlet-outlet; and a second manifold channel coupled to a second heat exchanger inlet-outlet. ### Claim 43 (depends on 42) The power supply system of claim 42, wherein the plurality of cooling channels are coupled between the first manifold channel and the second manifold channel. ### Claim 44 (depends on 42) The power supply system of claim 42, wherein the heat exchanger plate is configured to organize the plurality of cooling channels into a plurality of cooling units, and the plurality of cooling units are coupled in parallel between the first manifold channel and the second manifold channel. ### Claim 45 (depends on 42) The power supply system of claim 42, wherein the heat exchanger plate is configured to receive the heat transfer fluid from the first heat exchanger inlet-outlet and discharge the heat transfer fluid to the second heat exchanger inlet-outlet in a first operating period, and to receive the heat transfer fluid from the second heat exchanger inlet-outlet and discharge the heat transfer fluid to the first heat exchanger inlet-outlet in a second operating period before or after the first operating period. ### Claim 46 (depends on 42) The power supply system of claim 42, wherein the heat exchanger plate comprises aluminum. ### Claim 47 (depends on 24) The power supply system of claim 24, wherein the heat transfer fluid comprises ethylene glycol water (EGW), ethylene glycol, polyethylene glycol, water, or any combinations thereof. ### Claim 48 (depends on 38) The power supply system of claim 38, wherein the plurality of conduit segments of the fluid conveyance assembly further comprises: a first tube and a plurality of first hoses coupled to the first tube; and a second tube and a plurality of second hoses coupled to the second tube. ### Claim 49 (depends on 48) The power supply system of claim 48, wherein the first tube comprises a first trunk path leading from the first main inlet-outlet, and the plurality of first hoses comprises a first branch coupled to the first trunk path; and the second tube comprises a second trunk path leading from the second main inlet-outlet, and the plurality of second hoses comprises a second branch coupled to the second trunk path. ### Claim 50 (depends on 49) The power supply system of claim 49, wherein a plurality of fixed flow restrictors are coupled to the first hoses or the second hoses. ### Claim 51 (depends on 48) The power supply system of claim 48, wherein the first tube and the second tube comprise aluminum. ### Claim 52 (depends on 38) The power supply system of claim 38, wherein the first main inlet-outlet and the second main inlet-outlet are located at a top side of the aircraft. ### Claim 53 (depends on 38) The power supply system of claim 38, wherein the fluid conveyance assembly further comprises: a first trunk path leading from the first main inlet-outlet to a first branch and third branch; and a second trunk path leading from the second main inlet-outlet to a second branch and fourth branch, wherein the first trunk path and the second trunk path are equal in length. ### Claim 54 (depends on 53) The power supply system of claim 53, where the first main inlet-outlet and the second main inlet-outlet are located closer to the first branch than to the second branch.