Coolant circuit with a valve device for a proportional coolant volume distribution and motor vehicle with a coolant circuit of this type

Abstract

The invention relates to a coolant circuit (10) for an at least partially electrically driven motor vehicle (200), comprising a battery circuit (12) which is designed to cool at least one energy store (14) of the motor vehicle (200); a component circuit (16) which is designed to cool at least one electric drive (18) of the motor vehicle (200); a first heat exchanger (20), in particular a low-temperature cooler, around which ambient air (UL) flows; a first valve device (22) which is designed to conduct coolant from the first heat exchanger (20) to the battery circuit (12) and / or the component circuit (16); at least one coolant pump (24) which is assigned to the battery circuit (12); a second heat exchanger (26), in particular a chiller, which is thermally operatively connected to the battery circuit (12) and through which a refrigerant can flow, wherein the second heat exchanger (26) is arranged in the battery circuit (12) downstream of the energy store (14). According to the invention, a second valve device (32) is arranged in the battery circuit (12) between the energy store (14) and the second heat exchanger (26), the second valve device being designed to conduct a coolant volume flow downstream of the energy store (14) proportionally to the second heat exchanger (26) and to the coolant pump (24). The invention further relates to a motor vehicle (200) having a coolant circuit (10) of this type and to a valve device (32).

Description

[0001] Coolant circuit with valve device for proportional coolant volume distribution and motor vehicle with such a coolant circuit

[0002] DESCRIPTION:

[0003] The invention relates to a coolant circuit for an at least partially electrically powered motor vehicle, comprising a battery circuit configured to cool at least one energy storage device of the motor vehicle; a component circuit configured to cool at least one electric drive of the motor vehicle; a first heat exchanger, in particular a low-temperature cooler, around which ambient air flows; a first valve device configured to conduct coolant from the heat exchanger to the battery circuit and / or the component circuit; at least one coolant pump assigned to the battery circuit; a second heat exchanger, in particular a chiller, which is in thermal communication with the battery circuit and through which a coolant can flow, wherein the second heat exchanger is arranged downstream of the energy storage device in the battery circuit.Furthermore, the invention relates to a valve device and a motor vehicle with a coolant circuit.

[0004] Such a coolant circuit is known, for example, from DE 10 2021 113 380 A1. Reference is also made to US 2021 294 643 A1 and DE 10 2018 206 791 A1, as well as, with regard to a valve device, to EP 3 384 187 B1.

[0005] In the coolant circuits of electric vehicles, there are switching valves in the battery cooling circuit that make it impossible to regulate the flow rate distribution between the battery and the chiller when using "battery cooling via chiller." This can result in high coolant temperatures during battery cooling operation (active battery cooling via chiller). In a refrigeration system integrated via the chiller and operating with R744 (CO2) as the refrigerant, this can lead to problematic refrigeration circuit operation due to excessive suction pressures.

[0006] The object underlying the invention is seen in specifying a coolant circuit and a motor vehicle in order to avoid the above disadvantages, in particular to enable an optimized thermal interaction between the coolant circuit and the refrigeration system or the refrigerant circuit.

[0007] This object is achieved by a coolant circuit, a valve device, and a motor vehicle having the features of the respective independent patent claim. Advantageous embodiments with useful further developments are specified in the dependent patent claims.

[0008] What is proposed is a coolant circuit for an at least partially electrically powered motor vehicle, comprising a battery circuit configured to cool at least one energy storage device of the motor vehicle; a component circuit configured to cool at least one electric drive of the motor vehicle; a first heat exchanger, in particular a low-temperature cooler, around which ambient air flows; a first valve device configured to conduct coolant from the heat exchanger to the battery circuit and / or the component circuit; at least one coolant pump assigned to the battery circuit; and a second heat exchanger, in particular a chiller, which is in thermally operative connection with the battery circuit and through which a coolant can flow, wherein the second heat exchanger is arranged in the battery circuit downstream of the energy storage device.It is provided that a second valve device is arranged in the battery circuit between the energy storage device and the second heat exchanger, which is designed to proportionally direct a coolant volume flow downstream from the energy storage device to the second heat exchanger and to the coolant pump. This makes it possible to reduce the coolant volume flow at the second heat exchanger (chiller) in order to avoid critical refrigeration system operation (excessive suction pressure), while at the same time the coolant volume flow to the energy storage device (high-voltage battery) is not lost or does not become too low. Furthermore, with such a valve device, other functionalities of the coolant circuit are simultaneously retained, which are also available with a switching valve. In particular, it is still possible to flush the energy storage device (high-voltage battery) while the coolant circuit is connected in heat pump mode, for example.

[0009] It should be noted that the energy storage device may also be heated depending on the connection of the coolant circuit, especially if the battery circuit and the component circuit are interconnected or in fluid communication.

[0010] In the coolant circuit, the second valve device can have a valve insert which has two flow sections which are fluidically separated from one another, wherein a first flow section is designed such that it is in fluid communication with at least two and a maximum of three valve connections of the second valve device depending on a valve setting.

[0011] In the coolant circuit, the valve insert can have a second flow section which is designed such that, depending on the valve position, it is in fluid communication with only one valve connection and a maximum of two valve connections of the second valve device.

[0012] Such a valve insert enables different operating modes using a single valve device, with the second flow section providing, in particular, bypass functions, without the need to provide separate bypass lines and any valves required for this purpose, such as check valves, throttles, or the like, in the coolant circuit or battery circuit. In the coolant circuit, the valve insert can have a substantially cylindrical shape with a first recess forming the first flow section and a second recess forming the second flow section.

[0013] The recesses may be provided over only a portion of the total height of the cylindrical valve insert. In particular, the recesses are arranged so that they face the valve ports of the valve device.

[0014] In the coolant circuit, approximately 40% to 60% of the cylinder's base area can be recessed in the area of ​​the first recess, based on an imaginary cross-sectional plane. In particular, the first recess can be semicircular. This allows for different flow cross-sections to be provided at the respective valve ports, depending on the relative rotational position of the valve insert to the valve ports, so that the coolant volume flow can be directed proportionally to the respective valve ports.

[0015] Furthermore, a motor vehicle with at least partially electric drive, at least one energy storage device, a refrigeration system and a coolant circuit described above is proposed, wherein the refrigeration system and the coolant circuit are in thermal communication with one another via the second heat exchanger, such that coolant guided to the energy storage device can be cooled by means of the second heat exchanger.

[0016] The motor vehicle may have a control unit configured to regulate the second valve device of the battery circuit such that, during active cooling of the energy storage device, the coolant volume conducted via the second heat exchanger is adjusted as a function of a suction pressure detected in the refrigeration system. A portion of the coolant volume not conducted via the second heat exchanger is directed to the coolant pump to enable flushing in the battery circuit, in particular, direct return to the energy storage device. Alternatively or additionally, the temperature of the coolant and / or the temperature of the coolant may also be (co-)considered.

[0017] Also proposed is a valve device for a coolant circuit, wherein it is designed with a valve insert which has two fluidically separated flow sections, wherein a first flow section is designed such that it is in fluid communication with at least two and a maximum of three valve connections of the valve device depending on a valve setting, characterized in that a second flow section is designed such that it is in fluid communication with only one valve connection and a maximum of two valve connections of the valve device depending on the valve position.

[0018] In the valve device, the valve insert can have a substantially cylindrical shape with a first recess forming the first flow section and with a second recess forming the second flow section.

[0019] In the valve device, approximately 40% to 60% of a base area of ​​the cylinder can be cut out in the region of the first recess relative to an imaginary cross-sectional plane; in particular, the first recess can be semicircular.

[0020] In the valve device, the second recess can be lens-shaped.

[0021] In the valve device, the second flow section, when in fluid communication with a single valve port, can block that valve port, and the first flow section can be in fluid communication with three valve ports.

[0022] The valve insert can be adjustable in different rotational positions within an adjustment range, whereby in each of the rotational positions one valve connection is blocked by the second flow section and an effective flow cross-section can be adjusted for two valve connections.

[0023] The valve device may have four valve ports, wherein two adjacent valve ports are arranged substantially orthogonally to each other.

[0024] The valve device may be the second valve device of a coolant circuit described above.

[0025] The refrigerant circuit described above offers the following advantages in particular: Conversion to the use of refrigerant R744 (CO2) is possible. Due to the second valve system, only minor changes to existing circuits and components are required, eliminating the need for additional bypass lines (hoses) and, if necessary, a check valve and throttle in the bypass line.

[0026] Further advantages and details of the invention will become apparent from the following description of embodiments with reference to the figures.

[0027] Fig. 1 is a simplified and schematic representation of a coolant circuit in a motor vehicle;

[0028] Fig. 2 is a simplified and schematic sectional view of a second valve device of a battery circuit in a first valve position;

[0029] Fig. 3 shows a simplified and schematic sectional view of the second valve device of the battery circuit in a second valve position; Fig. 4 shows a simplified and schematic sectional view of the second valve device of the battery circuit in a third valve position.

[0030] Fig. 1 shows a simplified and schematic representation of a coolant circuit 10 for an at least partially electrically driven motor vehicle 200.

[0031] The coolant circuit 10 has a battery circuit 12 which is designed to heat or cool at least one energy storage device 14, for example a high-voltage battery, of the motor vehicle 200.

[0032] The coolant circuit 10 further comprises a component circuit 16 which is configured to cool at least one electric drive 18 of the motor vehicle 200.

[0033] A first heat exchanger 20, in particular a low-temperature cooler, around which ambient air UL flows, is integrated into the coolant circuit 10. A first valve device 22 is arranged downstream of the first heat exchanger 20 with respect to the coolant flow direction. The first valve device 22 is configured to conduct coolant from the first heat exchanger 20 to the battery circuit 12 and / or the component circuit 16.

[0034] The first valve device 22 is shown here in a simplified form as an octagon. It has four valve ports I to IV. In the coolant circuit 10, the coolant can enter the valve device 22 through valve port I or valve port III and then exit at valve ports II and / or IV, depending on the valve setting.

[0035] In this context, it should be noted that switching states of the first valve device 22 are also possible in which the first heat exchanger 20 is bypassed (bypass function). The first valve device 22 serves, in particular, to separate or connect the various circuits of the entire coolant circuit 10 or the system as needed (combined circuit). In this case, the first heat exchanger 20 can be bypassed or partially bypassed, for example, to regulate the temperature in the component circuit 16.

[0036] The coolant circuit 10 further includes at least one coolant pump 24 associated with the battery circuit 12. A second heat exchanger 26, in particular a chiller, is arranged in the coolant circuit 10, which is in thermal communication with the battery circuit 12 and through which a coolant can flow. The second heat exchanger 26 is arranged downstream of the energy storage device 14 in the battery circuit 12.

[0037] The integration of the second heat exchanger 26 into a refrigerant circuit 28 or a refrigeration system of the motor vehicle 200 is indicated by the dashed lines. A third heat exchanger 30, in particular a condenser or gas cooler, is also integrated into the refrigerant circuit 28. In the example shown, the third heat exchanger 30 is arranged downstream of the first heat exchanger or low-temperature cooler of the coolant circuit 10 with respect to a flow direction of ambient air UL.

[0038] In the battery circuit 12, a second valve device 32 is arranged between the energy storage device 14 and the second heat exchanger 26, which second valve device 32 is configured to direct a coolant volume flow downstream of the energy storage device 14 proportionally to the second heat exchanger 26 and to the coolant pump 24.

[0039] The second valve device 32 is shown here in a simplified form as an octagon.

[0040] It has four valve connections A to D, wherein in the battery circuit 12 the coolant passes through the valve connection A downstream of the energy storage device 14 into the valve device 32 and can then exit at the valve connections B and / or C and / or D depending on the setting of the valve. Further details of the second valve device 32 will be described later with reference to Figures 2 and 3. In Figure 1, several branches Ab1 to Ab5 are shown for the coolant circuit 10. It should be noted that the arrangement of these branches Ab1 to Ab5 is to be understood as exemplary and not necessarily restrictive. The representation of the branches Ab1 to Ab5 serves in particular to be able to describe the topology of the coolant circuit 10 in more detail below.

[0041] The following components, for example, can be assigned to the battery circuit 12 within the coolant circuit 10: valve connection IV of the first valve device 22, branches Ab2, Ab3, Ab4, coolant pump 24, second heat exchanger 26 (chiller) and second valve device 32.

[0042] The following components, for example, can be assigned to the component circuit 16 within the coolant circuit 10: valve connection II of the first valve device 22, branches Ab1 and Ab5 and a coolant pump 34.

[0043] Branch Ab1 forms a connection between the battery circuit 12 and the component circuit 16.

[0044] Simplified and schematic sectional views of the second valve device 32 are shown in Figs. 2 to 4.

[0045] From these illustrations, it can be seen that the four valve ports A, B, C, D open into a cylindrical valve seat 36. The second valve device 32 has a valve insert 38, which has two fluidically separated flow sections 40-1, 40-2.

[0046] A first flow section 40-1 is designed such that, depending on a valve setting or a rotational position of the valve insert 38 in the valve seat 36, it is in fluid communication with at least two and a maximum of three valve ports A, B, C, D of the second valve device 32. In the example of Fig. 2, the first flow section 40-1 is in fluid communication with the two valve ports B and C, which is illustrated by the two contour arrows.

[0047] The valve insert 38 has a second flow section 40-2 which is designed such that, depending on the valve position, it is in fluid communication with only one valve connection A, B, C, D and a maximum of two valve connections A, B, C, D of the second valve device 32.

[0048] In the example of Fig. 2, the second flow section 40-2 is in fluid communication with the two valve ports A and D, which is illustrated by the curved contour arrow.

[0049] In the example of Fig. 3, the valve insert 38 is rotated or positioned in a different valve position.

[0050] In this valve position, the first flow section 40-1 is in fluid communication with the valve ports A and B. The second flow section 40-2 is in fluid communication with the valve ports C and D.

[0051] In the example of Fig. 4, the valve insert 38 is rotated or positioned in a different valve position.

[0052] In this valve position, the first flow section 40-1 is in fluid communication with the valve ports A, B, and D. The second flow section 40-2 is positioned to block or close the valve port C.

[0053] From Fig. 4 it can also be seen that the valve insert is adjustable with respect to a flow cross-section effective in the direction of the valve connections B and D, so that depending on the rotational position of the valve insert 38, more or less coolant passes through the valve connections B and D. An adjustment range for the valve insert 38, in which coolant reaches both the valve connection B and the valve connection D, is simplified by the dash-dotted lines and the double arrow EB.

[0054] In other words, the second flow section 40-2 blocks the valve port C when it is in fluid communication with this valve port C. The first flow section (40-1) is in fluid communication with the three valve ports A, B and D.

[0055] The valve insert 38 can be adjusted in different rotational positions within the adjustment range EB, wherein in each of the rotational positions one valve connection C is blocked by the second flow section 40-2 and an effective flow cross-section can be adjusted for two valve connections B, D.

[0056] The four valve connections A, B, C, D of the second valve device 32 are arranged in particular such that two adjacent valve connections (A, B, C, D) are arranged substantially orthogonally to each other.

[0057] The valve insert 38 has a substantially cylindrical shape with a first recess 42-1 forming the first flow section 40-1 and with a second recess 42-2 forming the second flow section 40-2.

[0058] In the region of the first recess 42-1, approximately 40% to 60% of a base area of ​​the cylinder or valve seat 36 is recessed relative to an imaginary cross-sectional plane formed by the drawing plane in Figs. 2 and 3. As can be seen from Figs. 2 and 3, the first recess 42-1 can be approximately semicircular.

[0059] The second recess 42-2 is lens-shaped in Figs. 3 and 4.

[0060] However, it can also be designed as a type of bypass channel in the valve insert 38, as indicated by dashed lines in Fig. 2. The valve position of the second valve device 32 according to Fig. 2 is used, for example, in heat pump operation when heat from the electric drive 18 is to be transferred to the refrigeration circuit 28 by means of the second heat exchanger 26 (chiller). The coolant flows from the coolant pump 34 via the electric drive 18 and the first valve device 22. Depending on the switching position of the first valve device 22, the coolant circulates via the valve connections III and IV, bypassing the first heat exchanger 20 (low-temperature cooler), or via the valve connections I and IV, incorporating the first heat exchanger 20.It is also conceivable that heat is transferred from the ambient air UL to the coolant at the first heat exchanger 20 (cooler) and then transferred to the refrigerant at the second heat exchanger 26 (chiller).

[0061] The valve position of the second valve device 32 according to Fig. 3 is used, for example, for active cooling of the energy storage device 14. The coolant flows in the battery circuit 12 from the coolant pump 24 to the energy storage device 14, then through the valve connections A and B of the second valve device. The entire coolant volume flow is then passed through the second heat exchanger 26 (chiller) and returns to the coolant pump 24 via the branches Ab1, Ab2, Ab3, and Ab4. In other words, in such a circuit, active battery cooling occurs through the coolant circuit 28.

[0062] The valve position of the second valve device 32 according to Fig. 4 is used when the coolant volume flow at the second heat exchanger (chiller) must be reduced to avoid critical refrigeration system operation (excessive suction pressure), while at the same time ensuring that the coolant volume flow to the energy storage device 14 (high-voltage battery) is not lost or too low. The coolant volume flow can be distributed or directed proportionally to the second heat exchanger 26 and the coolant pump 24 within the adjustment range EB shown. Referring again to Fig.1 it is again pointed out that the invention also relates to a motor vehicle 200 with at least partially electric drive 18, at least one energy storage device 14, a refrigeration system 28 and a coolant circuit 10 described above, wherein the refrigeration system 28 and the coolant circuit 10 are in thermal connection with one another through the second heat exchanger 26 (chiller), such that coolant guided to the energy storage device 14 (high-voltage battery) can be cooled or heated by means of the second heat exchanger 26.

[0063] In this case, the motor vehicle 200 can have a control unit 202 which is designed to regulate the second valve device 32 of the battery circuit 12 in such a way that, when the energy storage device 14 is actively cooled, the coolant volume conducted via the second heat exchanger 26 is adjusted as a function of a suction pressure detected in the refrigeration system 28, wherein a portion of the coolant volume not conducted via the second heat exchanger 26 is conducted to the coolant pump 24 in order to enable flushing in the battery circuit 12, in particular a direct return to the energy storage device 14.

Claims

PATENT CLAIMS:

1. A coolant circuit (10) for an at least partially electrically powered motor vehicle (200), comprising a battery circuit (12) configured to cool at least one energy storage device (14) of the motor vehicle (200); a component circuit (16) configured to cool at least one electric drive (18) of the motor vehicle (200); a first heat exchanger (20), in particular a low-temperature cooler, around which ambient air (UL) flows; a first valve device (22) configured to conduct coolant from the first heat exchanger (20) to the battery circuit (12) and / or the component circuit (16); and at least one coolant pump (24) assigned to the battery circuit (12);a second heat exchanger (26), in particular a chiller, which is in thermal connection with the battery circuit (12) and through which a coolant can flow, wherein the second heat exchanger (26) is arranged in the battery circuit (12) downstream of the energy store (14), characterized in that a second valve device (32) is arranged in the battery circuit (12) between the energy store (14) and the second heat exchanger (26), which is designed to direct a coolant volume flow downstream of the energy store (14) proportionally to the second heat exchanger (26) and to the coolant pump (24); 2. Coolant circuit (10) according to claim 1, characterized in that the second valve device (32) has a valve insert (38) which has two fluidically separated flow sections (40-1, 40-2), wherein a first flow section (40-1) is designed such that it is in fluid communication with at least two and a maximum of three valve connections (A, B, C, D) of the second valve device (32) depending on a valve setting.

3. Coolant circuit (10) according to claim 2, characterized in that the valve insert (38) has a second flow section (40-2) which is designed such that, depending on the valve position, it is in fluid communication with only one valve connection (A, B, C, D) and a maximum of two valve connections (A, B, C, D) of the second valve device (32).

4. Coolant circuit (10) according to claim 2 or 3, characterized in that the valve insert (38) has a substantially cylindrical shape with a first recess (42-2) forming the first flow section (40-1) and with a second recess (42-2) forming the second flow section (40-2).

5. Coolant circuit (10) according to claim 4, characterized in that in the region of the first recess (42-1) with respect to an imaginary cross-sectional plane, approximately 40% to 60% of a base area of ​​the cylinder are recessed, in particular the first recess (42-1) is semicircular.

6. Motor vehicle (200) with at least partially electric drive, at least one energy storage device (14), a refrigeration system (28) and a coolant circuit (10) according to one of the preceding claims, wherein the refrigeration system (28) and the coolant circuit (10) are in thermal operative connection with one another through the second heat exchanger (26) such that coolant guided to the energy storage device (14) can be cooled or heated by means of the second heat exchanger (26).

7. Motor vehicle (200) according to claim 6, comprising a control unit (202) which is designed to regulate the second valve device (32) of the battery circuit (12) in such a way that, during active cooling of the energy storage device (14), the coolant volume conducted via the second heat exchanger (26) is controlled as a function of a value in the refrigeration system (28) detected suction pressure is set, wherein a portion of the coolant volume not passed through the second heat exchanger (26) is passed to the coolant pump (24) in order to enable flushing in the battery circuit (12).

8. Valve device (32) for a coolant circuit, wherein it is designed with a valve insert (38) which has two fluidically separated flow sections (40-1, 40-2), wherein a first flow section (40-1) is designed such that it is in fluid connection with at least two and a maximum of three valve connections (A, B, C, D) of the valve device (32) depending on a valve setting, characterized in that a second flow section (40-2) is designed such that it is in fluid connection with only one valve connection (A, B, C, D) and a maximum of two valve connections (A, B, C, D) of the valve device (32) depending on the valve position.

9. Valve device (32) according to claim 8, characterized in that the valve insert (38) has a substantially cylindrical shape with a first recess (42-2) forming the first flow section (40-1) and with a second recess (42-2) forming the second flow section (40-2).

10. Valve device according to claim 9, characterized in that in the region of the first recess (42-1) with respect to an imaginary cross-sectional plane, approximately 40% to 60% of a base area of ​​the cylinder are recessed, in particular the first recess (42-1) is semicircular.

11. Valve device according to one of claims 8 to 10, characterized in that the second recess (42-2) is lens-shaped.

12. Valve device according to one of claims 8 to 11, characterized in that the second flow section (40-2), when it is in fluid connection with a single valve connection (A, B, C, D), blocks this valve connection (A, B, C, D), and that the first flow section (40-1) is in fluid connection with three valve connections (A, B, C, D).

13. Valve device according to claim 12, wherein the valve insert (38) is adjustable in different rotational positions within an adjustment range (EB), wherein in each of the rotational positions the one valve connection is blocked by the second flow section (40-2) and an effective flow cross-section is adjustable for two valve connections.

14. Valve device according to one of claims 8 to 13, characterized in that it has four valve connections (A, B, C, D), wherein two adjacent valve connections (A, B, C, D) are arranged substantially orthogonally to each other.

15. Valve device according to one of claims 8 to 14, characterized in that it is the second valve device of a coolant circuit according to one of claims 1 to 5.

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