Coolant unit, coolant circuit, indirect thermal management system, and electric vehicle

Abstract

The invention relates to a coolant unit (100) for a coolant circuit (200) of an electric vehicle, comprising: a housing portion (2) which forms a housing chamber (3) and which encapsulates at least one component of the coolant circuit and a supply line portion (10) for this component and a discharge line portion (12) from this component, a pressure sensor (8) for monitoring a pressure state within the housing chamber (3) and a pressure switch (DS) in an electrical line between a positive pole (Kl. 30) or negative pole (GND) and the pressure sensor (8), wherein the pressure switch (DS) is also encapsulated by the housing portion (2). In the event of a fault, when the electric vehicle is parked and the pressure sensor (8) is disconnected from a power supply, the pressure switch (DS) can be closed in a pressure-dependent or pressure-based manner and thus the pressure sensor (8) can be supplied with power, i.e. the pressure sensor (8) can be activated. The invention also relates to a coolant circuit, an indirect thermal management system and an electric vehicle.

Description

[0001] 202500185

[0002] 1

[0003] Description

[0004] Refrigerant unit, refrigerant circuit, indirect thermal management system and electric vehicle

[0005] The invention relates to a refrigerant unit, a refrigerant circuit with such a refrigerant unit, an indirect thermal management system and an electric vehicle.

[0006] The object of the present invention is to improve the safety of a refrigerant circuit.

[0007] This problem is solved by a refrigerant unit proposed and protected according to claim 1.

[0008] The proposed refrigerant unit allows for the detection of leaks within the housing.

[0009] If, in the event of a fault, refrigerant escapes inside the housing or housing section or in the housing space, this causes - due to the refrigerant vapor - a pressure increase in the housing space, which the proposed pressure sensor can detect as such.

[0010] This can then, for example, supply power to a compressor or...

[0011] Compressor interrupted and / or a fault message (or workshop service message) is displayed to a driver in an instrument cluster or display.

[0012] The proposed pressure switch is to be understood as a device, for example in the form of a diaphragm, which is designed to react to a pressure change in the housing and close the line to the pressure sensor at and above a certain pressure. 202500185

[0013] 2

[0014] The proposed refrigerant unit allows the proposed pressure sensor to be disconnected from a power supply while or when an electric vehicle is parked or not in operation.

[0015] Thus, the proposed refrigerant unit contributes to energy savings, while a control unit connected to the pressure sensor – of such a refrigerant circuit – is put into a so-called sleep mode, also called hibernate mode, because the pressure sensor does not need to be supplied with voltage permanently or cyclically in order to detect or record such a leakage within the housing or housing section or housing space.

[0016] The proposed refrigerant unit thus enables energy-saving detection of such a leak, which, for safety reasons, must also be detected when the electric vehicle is switched off or parked and not in operation.

[0017] It can also be said that the proposed pressure sensor – in such a switched-off or parked state of the electric vehicle – can only be awakened or activated in such a case of fault or leakage.

[0018] It can also be said that the proposed pressure sensor – in such a switched-off or parked state of the electric vehicle – is only supplied with a voltage and thereby awakened or activated, or can be awakened or activated, when actually needed, i.e., in such a fault case.

[0019] And the encapsulating housing advantageously prevents the formation of an ignitable atmosphere in an electric vehicle.

[0020] The housing can be designed to be gas-tight or hermetically sealed. 202500185

[0021] 3

[0022] Alternatively, the housing can also be equipped with a pressure equalization device to allow pressure equalization in the event of higher differential pressures compared to the vehicle environment. Such a pressure equalization device can, for example, be in the form of a rupture disc provided, arranged, or formed on the housing.

[0023] The refrigerant to be used here should be a flammable or highly flammable refrigerant, such as one of flammability class A3, e.g. in the form of propane (R290).

[0024] In one embodiment, the housing or housing section encapsulates a compressor, an inlet line section to the compressor, and an outlet line section from the compressor, shielding them from the environment.

[0025] In another embodiment, the housing or housing section additionally or alternatively encapsulates an accumulator as well as an inlet line section to the accumulator and an outlet line section from the accumulator and shields it from the environment.

[0026] An accumulator is a storage container that holds a refrigerant in liquid form. In a refrigerant circuit, such an accumulator can be located in a low-pressure section between an evaporator and a compressor.

[0027] In another embodiment, the housing or housing section can additionally or alternatively encapsulate and shield from the environment a receiver-drier, an inlet line section to the receiver-drier, and an outlet line section from the receiver-drier. 202500185

[0028] 4

[0029] A receiver drier is a device that fulfills two functions:

[0030] • Absorbing and storing liquid refrigerant downstream of a condenser and

[0031] • Removing moisture and impurities from the refrigerant using a desiccant.

[0032] In a refrigerant circuit, such a receiver-drier can be located in a high-pressure section between the condenser and an expansion valve, ensuring that only liquid refrigerant reaches the expansion valve, which is crucial for the efficient operation of such a refrigerant circuit.

[0033] In another embodiment, the housing or housing section additionally or alternatively encapsulates an expansion valve, an inlet line section to the expansion valve, and an outlet line section from the expansion valve, and shields them from the environment.

[0034] In another version, the housing also incorporates a condenser and / or an evaporator, which is not encapsulated, but forms part of the housing or a housing wall and thus the housing space.

[0035] Furthermore, a refrigerant circuit with a refrigerant unit of the type described above is proposed.

[0036] Furthermore, an indirect thermal management system with a refrigerant circuit of the type described above is proposed.

[0037] Furthermore, a vehicle or electric vehicle with a refrigerant unit of the type described above is proposed. 202500185

[0038] 5

[0039] Furthermore, the use of a refrigerant unit of the type described above in a vehicle or electric vehicle is proposed.

[0040] It is also proposed to use a refrigerant unit of the type described above with a flammable refrigerant.

[0041] The refrigerant used can be, for example, propane - also known as R290.

[0042] The invention will now be explained in detail with reference to the figures. Further advantageous embodiments of the invention will become apparent from the dependent claims and the subsequent description of preferred embodiments. These are shown partly schematically and functionally:

[0043] Fig. 1 shows a proposed refrigerant unit,

[0044] Fig. 2 shows an indirect heat transfer medium circuit system and

[0045] Fig. 3 shows a circuit diagram for the proposed refrigerant unit.

[0046] The proposed refrigerant unit 100 according to Fig. 1 is part of a vehicle or electric vehicle. This refrigerant unit 100 is also part of a refrigerant circuit 200 in which heat is transported by means of a conveyed refrigerant.

[0047] The refrigerant unit 100 has a housing 2 with a housing space 3, wherein the housing 2 contains a compressor 4, an inlet line section 10 to the compressor 4, an outlet line section 12 from the compressor 4, an accumulator or collection tank, an inlet line section 16 to the accumulator, an outlet line section 14 from the accumulator, an expansion valve 22, an inlet line section to the expansion valve 22, and 202500185

[0048] 6

[0049] a drain line section to the expansion valve 22 is gas-tight or hermetically sealed and encapsulated, and shielded from the environment.

[0050] Alternatively, the housing 2 can simply act as an encapsulating or shielding element and be designed or configured with a pressure equalization device (not shown here) to enable pressure equalization in the event of higher differential pressures compared to the vehicle environment. Such a pressure equalization device can, for example, be in the form of a rupture disc provided or arranged on the housing.

[0051] A pressure sensor 8 is also attached to or arranged on the housing 2, which extends into the housing space 3 in order to be able to detect a pressure state in the housing space 3 or within the housing 2 encapsulating the aforementioned components or in the housing space 3.

[0052] The pressure sensor 8 is, for example, in the form of a so-called MEMS.

[0053] (Micro-Electro-Mechanical System). Such a MEMS is a tiny or miniaturized element or component that combines minute mechanical components with control electronics. A micromechanical structure is thus integrated into a single chip.

[0054] In the event of a leak in at least one of these components within housing 3, pressure builds up in housing 3 due to the escaping refrigerant or refrigerant vapor. This pressure must be detected to indicate a fault in the refrigerant unit 100 or the aforementioned leak within this refrigerant unit 100. This also applies when an electric vehicle is switched off or parked, i.e., not in operation.

[0055] The indirect heat transfer medium circuit system 300 according to Fig. 2 - also referred to as indirect thermal management system or thermal system or heat management system - has such a refrigerant circuit 100 as well as a 202500185

[0056] 7

[0057] Liquid circuit system 200, whereby the liquid circuit system 200 is depicted here in a highly simplified form.

[0058] For the sake of simplicity, the liquid circuit system 200 is illustrated with only one liquid cooling circuit – the lower section in Fig. 2 – and only one liquid heating circuit – the upper section in Fig. 2. The liquid cooling circuit has its own liquid pump EWPi, which circulates a liquid within the cooling circuit. The liquid heating circuit has its own liquid pump EWP2, which circulates a liquid within the heating circuit.

[0059] The fluid pumped in each fluid circuit system 200 is, for example, a water-glycol mixture.

[0060] In the liquid cooling circuit, for the sake of simplicity, only one heat sink in the form of an evaporator HVAC-C (Heating, Ventilation, and Air Conditioning; C = Cooler) is illustrated.

[0061] And in the liquid heating circuit, for the sake of simplicity, only one heat source in the form of a condenser HVAC-H (Heating, Ventilation, and Air Conditioning; H = Heater) is illustrated.

[0062] The acronym HVAC stands for Heating, Ventilation, and Air Conditioning. It refers to a system for regulating the temperature and humidity in a vehicle cabin.

[0063] The liquid circuit system 200 is thermally connected to the refrigerant circuit 100 – or vice versa – via a first heat exchanger in the form of an evaporator 18 of the refrigerant circuit 100 and via a second heat exchanger in the form of a condenser 20 of the refrigerant circuit 100.

[0064] 8

[0065] Fig. 2 shows the proposed housing 2, which encapsulates the aforementioned components of the cold central circuit, with the housing space 3 into which the pressure sensor 8 protrudes.

[0066] The housing 2 can be designed to also accommodate the evaporator 18 and / or the condenser 20, but without encapsulating them. In this case, the heat exchanger 18 and / or the heat exchanger 20 form an associated housing wall and thus the housing space 3. The respective heat absorption by the evaporator 18 – from the liquid cooling circuit of the aforementioned liquid circuit system 200 – on the one hand, and the heat dissipation by the condenser 20 – indirectly via the liquid heating circuit of the aforementioned liquid circuit system 200 – to the vehicle environment on the other hand are thus ensured.

[0067] Alternatively, the evaporator 18 and / or the condenser 20 can also be arranged outside the housing 2, i.e., not enclosed or contained by the housing 2. In this case, an associated inlet pipe section to the evaporator 18, an outlet pipe section from the evaporator 18, and / or an associated inlet pipe section to the condenser 20, as well as an outlet pipe section from the condenser 20, are also arranged partially inside and outside the housing 2.

[0068] Fig. 3 illustrates a proposed pressure switch DS in a line between a terminal KL. 30 or a positive terminal – that is, the positive lead of a vehicle battery – and the pressure sensor 8. The pressure switch DS is also arranged within the housing 2 – which encapsulates the aforementioned components of the refrigerant circuit – or encapsulated by the housing 2, or received by the housing space 3.

[0069] This pressure switch DS has the following function: 202500185

[0070] 9

[0071] When the electric vehicle is switched off or parked – or is not in operation – the power supply to such a pressure sensor 8 is interrupted. The open switch shown in Fig. 3 above the pressure switch DS does not belong to the pressure switch DS and symbolizes or illustrates such a power interruption of the pressure sensor 8 when the electric vehicle is switched off or parked and not in operation.

[0072] In the event of a fault or leakage, the proposed pressure switch DS is forced into its closed position by the pressure in housing chamber 3, thus supplying the pressure sensor 8 with a voltage. The pressure sensor 8 is therefore activated based on pressure when the electric vehicle is switched off or parked and not in operation.

[0073] In the event of a fault or leak, the pressure in housing chamber 3 increases and acts on the pressure switch DS, causing it to close in a pressure-based or pressure-dependent manner, or to assume a closed position. This means that the pressure switch DS assumes this closed position at and above a certain pressure value.

[0074] In a fault-free or leak-free case, however, this pressure switch DS is open or assumes an open position because there is no increased pressure or pressure condition in the housing space 3.

[0075] In the event of a fault or leakage, this results in a current flow between terminal 30 and a common ground connection GND (Ground), and thus through this pressure sensor 8.

[0076] Thus, when the electric vehicle is switched off or parked, the pressure sensor 8 is only awakened or activated or switched on by the pressure switch DS when necessary, i.e., in the event of a fault or leakage, and a pressure or pressure value or voltage value detected by the pressure sensor 8 can be displayed.

[0077] 10

[0078] The information is transmitted to the TMC control unit in order to detect or register the fault and then store it in a fault memory of the electric vehicle.

[0079] The pressure sensor 8 - approximately in the form of the MEMS

[0080] (Micro-Electro-Mechanical System) with a chip (circuit logic SL) on which a micromechanical structure is applied – the detected pressure information is digitized, i.e., transmitted in binary form to the TMC control unit. This wakes the TMC control unit from a sleep mode (hypernate mode), into which it is placed when the electric vehicle is switched off or parked. A mechanically deformable measuring element ME, or the micromechanical structure itself, is pressure-dependent, thereby generating a pressure-dependent voltage signal.

[0081] The gateway G shown in Fig. 3 represents an interface to a vehicle network, for example in the form of a LIN (Local Interconnect Network).

[0082] Although the preceding description explains exemplary embodiments, it should be noted that a multitude of variations are possible. Furthermore, it should be emphasized that the exemplary embodiments are merely examples and are not intended to restrict the scope of protection, applications, or structure in any way. Rather, the preceding description provides the skilled person with a guideline for implementing at least one exemplary embodiment, whereby various modifications, particularly with regard to the function and arrangement of the described components, can be made without departing from the scope of protection as defined by the claims and these equivalent combinations of features.

Claims

202500185 11 Patent claims 1. Refrigerant unit (100) for a cold medium circuit (200) of an electric vehicle, comprising: a housing section (2) forming a housing space (3) which encapsulates at least one component of the refrigerant circuit as well as an inlet line section (10) to this component and an outlet line section (12) from this component and shields it from an environment, a pressure sensor (8) for monitoring a pressure condition within the housing space (3) in order to detect a leakage of the refrigerant unit (100) within the housing space (3), wherein the pressure sensor (8) is received by the housing (2) and at least partially projects into the housing space (3), and a pressure switch (DS) - in an electrical line between a positive terminal (terminal 30) or negative terminal (GND) and the pressure sensor 8 -, wherein the pressure switch (DS) is also encapsulated by the housing section (2) and is arranged within the housing space (3), wherein, when the electric vehicle is switched off and the pressure sensor (8) is disconnected from a power supply, the pressure switch (DS) can be closed in the event of a fault by the pressure in the housing space (3) if there is an increased pressure in the housing space (3) due to leakage caused by refrigerant escaping into the housing space (3), which causes the pressure switch (DS) to assume a closed position, so that the pressure sensor (8) can be supplied with a voltage in the event of a fault and when the vehicle is switched off.

2. Refrigerant unit (100) according to claim 1, wherein the housing section (2) encapsulates a compressor (4), an inlet line section (10) to the compressor, and an outlet line section (12) from the compressor. 12 3. Refrigerant unit (100) according to one of the preceding claims, wherein the housing section (2) encapsulates an accumulator (6) as well as an inlet line section (16) to the accumulator and an outlet line section (14) from the accumulator.

4. Refrigerant unit (100) according to one of the preceding claims, wherein the housing section (2) encapsulates a receiver-drier as well as an inlet line section to the receiver-drier and an outlet line section from the receiver-drier.

5. Refrigerant unit (100) according to one of the preceding claims, wherein the housing section (2) encapsulates an expansion valve (22) as well as an inlet line section to the expansion valve and an outlet line section from the expansion valve.

6. Refrigerant unit (100) according to one of the preceding claims, wherein a condenser (20) and / or an evaporator (18) is / are accommodated by the housing section (2), which form the housing (2) and the housing space (3).

7. Refrigerant circuit (200) with a refrigerant unit (100) according to one of the preceding claims.

8. Indirect thermal management system with a refrigerant circuit according to claim 7.

9. Electric vehicle with a refrigerant unit (100) according to any one of the preceding claims 1 to 6.

10. Use of a refrigerant unit (100) according to any one of the preceding claims 1 to 6 in an electric vehicle. 202500185 13 11. Use of a refrigerant unit (100) according to any one of the preceding claims 1 to 7 with a flammable refrigerant.

12. Use according to claim 11, wherein propane (R290) is used as the refrigerant.

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