Cooling system of charging cable for electric vehicle

Abstract

The present disclosure relates to a cable cooling system (3) for cooling an embedded portion of a battery charging cable (9) of a battery-driven vehicle, the vehicle comprising an air conditioning system (2) operating in a coolant fluid circuit configured to absorb heat by phase change expansion, such as a compressor (29) operated air conditioning system. According to the present disclosure, the cable cooling system (3) comprises a cable coolant circulating in a closed loop (41) for absorbing heat from the charging cable (9) through a cable cooling heat exchanger (311) incorporated in the air conditioning coolant loop (2) to be cooled by the air conditioning coolant fluid loop, and discharging heat into the air conditioning coolant fluid (31). Preferably, the cooling liquid is a non-dielectric liquid, such as an ethylene glycol solution, which enables very efficient cooling using simple and standard components.

Description

TECHNICAL FIELD

[0001] The present invention relates to a system for cooling an electric vehicle's charging cable and its rechargeable battery. BACKGROUND

[0002] Today, electric vehicle charging cables mostly do not have specific cooling functions, which greatly limits the current capacity through them and thus the speed of battery charging.

[0003] In document US2019061543A1, it has been proposed to cool the embedded part of the charging device by means of a heat exchanger integrated within the phase change circuit of the vehicle air conditioning system.

[0004] In document US11380460B2, it has been proposed to insert the embedded part of the charging cable into an inner tube of a heat exchanger, where the inner tube is immersed in a refrigerant fluid circulating through a phase change circuit with an evaporator and a condenser.

[0005] However, these solutions are still obstructed inside the vehicle and become a source of cost and complexity.

[0006] One purpose of the present invention is to overcome some or all of the drawbacks of the prior art. In particular, the present invention aims to propose a cooling system for such a charging cable that achieves a better compromise between performance, compatibility, reliability and simplicity of manufacture, installation and adaptation to various constraints compared to existing vehicles or vehicle types. SUMMARY

[0007] According to the present disclosure, these objectives are achieved in part or in whole by the cooling system and method having the features mentioned in the claims. The claims form an integral part of the technical disclosure provided herein in relation to the present disclosure.

[0008] In the present disclosure, it must be understood that the term "charging cable" is also intended to include various devices of the embedded circuit that are related and connected to the cable conductors from the charging port to the traction battery, such as the charging port, connection devices and terminals, and / or power conversion devices.

[0009] In this context, a cooling system according to claim 1 is disclosed. The device can also optionally comprise at least one feature described in any one of claims 2 to 7 and 8.

[0010] The present disclosure also relates to a method for cooling such a charging cable according to claim 9.

[0011] Thanks to these provisions, in this way, the complexity of the cable heat dissipation system is greatly reduced, since the climate control system almost does not need to be modified to perform this additional function.

[0012] Refrigerant fluid from the vehicle climate control system is diverted to the cable heat exchanger. There or before, it is expanded to achieve a low temperature. In the heat exchanger, the fluid evaporates, effectively cooling the liquid flowing in the charging cable. The refrigerant is then compressed to high pressure and condensed in the climate control condenser, preferably through the same compressor and circuit used by the refrigerant of the cabin evaporator(s).

[0013] Various embodiments of the application are contemplated herein, including optional features disclosed herein in all possible combinations thereof. BRIEF DESCRIPTION OF DRAWINGS

[0014] Other advantages and features will become apparent from examination of the following detailed description, taken in connection with the accompanying drawings, in which:

[0015] - Figure 1 is a schematic diagram illustrating an example of an embodiment of the present disclosure;

[0016] - Figure 2a is a schematic diagram illustrating in more detail the cooling fluid circuit of Figure 1 , in a first example of an embodiment of the present disclosure, having two externally insulated tubular distinct insulation compartments, each compartment bathing a non-insulated conductor.

[0017] - Figure 2b is a cross-sectional perspective view of the tubular conductor of Figure 2a , in a second example of an embodiment of the present disclosure, bathing a non-insulated conductor.

[0018] - Figure 3 is a schematic diagram illustrating in more detail the cooling fluid circuit of Figure 1 , in a second example of an embodiment of the present disclosure, having two distinct insulation compartments, each compartment bathing a non-insulated conductor.

[0019] - Figure 4 is a schematic diagram illustrating in more detail the cooling fluid circuit of Figure 1 , in a third example of an embodiment of the present disclosure, having a single cooling compartment bathing two distinct insulation conductors. DETAILED DESCRIPTION

[0020] In the various drawings, like or similar elements are referenced with the same reference numerals.

[0021] Figure 1 A global cooling system 1 of a battery powered vehicle is shown, the battery 91 of which can be charged through a charging cable 9. In this example, the charging cable comprises a connection box 92, and one or more electrical conductors 40, and a charging port 93, which are operatively connected together for supplying power to the battery from an external source (not shown) through the charging cable 93 plugged in.

[0022] The cable cooling system 3 comprises a cable cooling fluid which circulates in a closed circuit 41 for absorbing heat from the charging cable 9 and discharging said heat to the air conditioning refrigerant fluid 31 through the cable cooling heat exchanger 311.

[0023] Figure 1 An air conditioning system 2 is shown operating with a refrigerant fluid circuit configured to absorb heat by phase change expansion, here with a compressor 29 which raises the pressure of the refrigerant and circulates it towards and through a condenser heat exchanger 211 31. It has a first cooling branch 22 which contains a cabin heat exchanger 221 arranged downstream of an expansion valve 222 for cooling the internal air of the vehicle. Such an air conditioning system 2 is for example of known type and can be a system already built into an existing vehicle. An example of refrigerant fluid is the r1234yf fluid.

[0024] In this example, the cable cooling fluid is cooled by circulating in a first circuit 311a of the cable cooling heat exchanger 311, thanks to the second circuit 311b of said heat exchanger being combined downstream of a discharge valve 312 in a branch of the vehicle air conditioning system 2, here in a second branch 31 of the air conditioning refrigerant fluid circuit in parallel with the first cooling branch 22. A three-way valve 30 connects the first cooling branch 21 and the second cooling branch 31 to the condenser branch 21 in order to be able to select one or the other or both of the cooling of the first cooling branch and the second refrigeration branch as required.

[0025] It can be seen that, compared to standard known and industrialized air conditioning systems, according to the present disclosure, only very few devices and parts need to be added to build a charging cable cooling system.

[0026] The cooling fluid circuit 41 is a non-pressurized or moderately pressurized circuit containing a cooling fluid which preferably does not require a phase change and has no or only a small pressure differential. Its components 41, 49 therefore only require a very simple technology, similar to the best known components for cooling thermoelectric machine fluids.

[0027] The second cooling branch 31 only requires standard pipes and a bidirectional valve 30 and a three-way valve 312, similar to the well-known basic components of a standard air conditioning system. Even the cable cooling heat exchanger 311 can be derived from a known evaporative heat exchanger such as the cabin evaporator 221 or manufactured with similar technology.

[0028] In addition, compared to a standard cabin air conditioning circuit, the air conditioning circuit 2 disclosed herein uses standard technology and mainly standard components which can be easily available in the air conditioning system industry, such as the expansion valve 312 or the three-way valve 30.

[0029] Figure 2a A first example of an embodiment of the disclosure is shown in more detail Figure 1 cooling fluid circuits. In this example, there are two distinct cooling fluid circuits 41 and 51 which are insulated from each other and from the rest of the vehicle. Both circuits 41, 51 are cooled within two first circuits of the same cable cooling heat exchanger 311, but two distinct exchangers could also be included. Both circuits 41, 51 are here shown as being circulated by the same pump 49, but two distinct pumps could also be included.

[0030] As Figure 2b As shown in more detail, the shape of each conductor 40 and 50 is a metallic tubular conductor. Electrically, this tubular conductor is externally insulated by an insulation layer 400 and 500 respectively. They each define an internal compartment 411, 511 in which the cooling fluid of their respective circuit 41, 51 is circulated.

[0031] It is understood that the cooling fluid within such a conductor is in direct contact with the metal of the conductor, enabling a much larger area to exchange heat than when a liquid is surrounding a standard wire-like conductor. Furthermore, it is easy to provide external insulation directly around the outer surface of the tube.

[0032] The rest of each cable cooling circuit 41, 51 is also electrically insulated from its environment, for example by using insulated hoses or wires. In this example, each of these circuits 41, 51 is cooled in a separate and / or externally insulated part of the heat exchanger 311. In this example, these parts of the heat exchanger 311 are connected on two parallel branches of the air conditioning circuit 31, but various other configurations are also included, such as in series. Preferably, the air conditioning cooling fluid of the air conditioning system 2 is an electrically insulating fluid, for example a r1234yf type fluid. Preferably, a direct metallic separation is then provided between the two circuits of each heat exchanger part 311, thereby having the best efficiency without needing to have the air conditioning cooling circuit 31 itself electrically insulated.

[0033] Other components of the charging cable 9, here the battery junction box 92 and the charging port 93 as well as the power conversion device 94, are also cooled by the cooling fluid circulating in one or both of the cooling fluid circuits 41, 51, either directly or through an insulated heat exchange contact surface.

[0034] In this exemplary embodiment, it can be seen that a non-dielectric cooling fluid can be used in these cooling fluid circuits 41, 51, for example a 50% glycol solution or any known cooling fluid. Although it requires building insulated circuits 41, 51, it is also able to conduct very efficiently with the conductors 40, 50 and uses a liquid which is more efficient, easier to find, cheaper and less harmful to the environment than most dielectric cooling fluids.

[0035] Figure 3 and Figure 4 are shown in more detail Figure 1 The cooling liquid circuits of

[0036] In the example of Figure 3 the two electrical conductors 40 and 50 are respectively directly immersed in a cable cooling liquid bath in a compartment 411, 511 of a separate charging cable cooling insulation circuit 41, 51.

[0037] In the example of Figure 4 the two electrical conductors 40 and 50 are respectively covered by an insulation layer 400 and 500 and are immersed in the same cooling liquid bath within the same compartment 411 of the cooling liquid circuit 41.

[0038] Of course, the present disclosure is not limited to the previously described examples and many adaptations can be made to these examples without departing from the scope of the present disclosure.

[0039] List of reference signs

[0040] 1 global cooling system

[0041] 2 air conditioning system

[0042] 21 condenser branch

[0043] 22 first cooling branch - compartment cooling branch

[0044] 222 expansion valve of the compartment branch

[0045] 29 compressor

[0046] 3 cable cooling system

[0047] 30 three-way valve

[0048] 31 second cooling branch - cable cooling branch

[0049] 311 cable cooling heat exchanger / evaporator

[0050] 311a first circuit of the cable cooling exchanger - cooling liquid

[0051] 311b second circuit of the cable cooling exchanger - refrigerant fluid

[0052] 312 expansion valve of the cable cooling branch

[0053] 40, 50 charging conductors of the charging cable

[0054] 400, 500 insulation layer of the conductors

[0055] 41, 51 cable cooling liquid circuit

[0056] 411,511 conductor compartment of a cable cooling liquid circuit

[0057] 49 circulating pump

[0058] 9 charging cable

[0059] 91 battery to be charged

[0060] 92 connection / joining box

[0061] 93 charging port

[0062] 94 power conversion

Claims

1. A cable cooling system (3) for cooling an embedded portion of a battery charging cable (9) of a battery-powered vehicle, said vehicle including an air conditioning system (2) operating in a coolant fluid loop configured to absorb heat through phase change expansion, said air conditioning system being, for example, an air conditioning system operated by a compressor (29). Its features are, The cable cooling system (3) includes a cable coolant that circulates in a closed loop (41) to absorb heat from the charging cable (9) via a cable cooling heat exchanger (311) and discharge the heat into the air conditioning coolant fluid (31), which is integrated into the air conditioning coolant loop (2) to be cooled by the air conditioning coolant fluid loop.

2. The system (3) according to the preceding claim, characterized in that, The cable cooling fluid is a pure liquid fluid that is cooled by circulating through the first circuit (311a) of the cable cooling heat exchanger (311) via a second circuit (311b) of a heat exchanger incorporated in a branch (31) of the vehicle air conditioning system (2), particularly downstream of the discharge valve (312).

3. The system (3) according to any one of the preceding claims, characterized in that, The air conditioning coolant fluid circuit has a first cooling branch (22), which is combined with a compartment heat exchanger (221) arranged to cool the interior air of the vehicle. Furthermore, the cable cooling heat exchanger (311) is integrated downstream of the discharge valve (312) into a second cooling branch (31) of the air conditioning refrigerant fluid circuit, which is connected in parallel with the first cooling branch.

4. The system (3) according to any one of the preceding claims, characterized in that, The cable coolant (41, 51) is a non-dielectric liquid that is usually always in the liquid phase. Furthermore, it includes one or more independent conductor cooling circuits (41, 51, respectively), which are insulated to provide electrical contact insulation of their cable coolant relative to the outside and to other conductor cooling circuits (51, 41, respectively).

5. The system (3) according to the preceding claim, characterized in that, One or more conductors of the charging cable have an internal longitudinal cavity that forms part of a cooling circuit for the charging cable, in which a coolant circulates and is in direct contact with the conductor. The conductor is preferably tubular in shape and electrically insulated on its outer surface.

6. The system (3) according to any one of claims 4 or 5, characterized in that, Only direct metal separation is provided between two loops in one or each of the plurality of portions of the cable heat exchanger (311), the portions of the cable heat exchanger (311) being electrically insulated themselves.

7. The system (3) according to any one of claims 1 to 4, characterized in that, The system includes one or more insulating layers (400 and 500, respectively), each insulating layer being tightly applied to an electrical conductor (40 and 50, respectively) of one electrical phase of the charging cable (9) to insulate the conductor from the cable coolant (411) it cools.

8. The system (3) according to the preceding claim, characterized in that, The conductors (40, 50) of different electrical phases of the charging cable (9) are cooled by a common charging cable cooling circuit (41).

9. A method for cooling an embedded portion of a battery charging cable (9) of a battery-powered vehicle, the vehicle including an air conditioning system (2) operating in a coolant fluid loop configured to absorb heat through phase change expansion, the air conditioning system being an air conditioning system such as a compressor (29), the method comprising cooling the charging cable (9) with a cooling system (3) according to any one of the preceding claims.

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