Safety valve unit with several valve stages for a refrigeration system; refrigeration system with such a safety valve unit and motor vehicle with such a refrigeration system

Abstract

The invention relates to a safety valve unit (50) for a refrigeration system (10) of a motor vehicle (200), comprising a mechanically pressure-controlled first valve stage (V1) which is configured to be opened as a function of a refrigerant pressure in order to allow refrigerant to temporarily escape from the refrigeration system (10) when a predetermined refrigerant pressure in the refrigeration system (10) is exceeded; a signal-controlled second valve stage (V2) which is configured to be actuated as a function of an input signal in order to allow refrigerant to escape from the refrigeration system (10) independently of the refrigerant pressure, wherein the safety valve unit (50) is designed as an integrated component which is connectable or connected to a refrigerant line section (52) and / or a functional component, in particular a refrigerant compressor or heat exchanger, of the refrigeration system (10).Furthermore, a refrigeration system with such a safety valve unit and a motor vehicle with such a refrigeration system are described.

Description

[0001] The invention relates to a safety valve unit for a refrigeration system of a motor vehicle, a refrigeration system with such a safety valve unit and a motor vehicle with such a refrigeration system.

[0002] Various options for draining refrigerant from a refrigerant circuit are known from the prior art. For example, DE 10 2013 016 481 A1, DE 10 2014 004 957 A1, DE 10 2014 014 716 A1, and WO 2007 087 992 A1 describe the targeted discharge of refrigerant in the event of certain unforeseen events in a motor vehicle. Reference is also made to DE 10 2014 005 045 A1 and DE 10 2015 214 307 A1, which concern concepts for monitoring and ventilating a motor vehicle interior, respectively.

[0003] In refrigeration systems, especially those operated with the refrigerant R744, situations can arise in which excessive pressure occurs in the refrigerant circuit, depending on the operating condition and refrigerant charge. This can particularly damage low-pressure components of the refrigeration system, as these are designed for lower pressure conditions. Furthermore, in addition to undesirable refrigerant pressure levels, collision events must also be considered, in which, in particular, the leakage of refrigerant into the vehicle interior must be prevented.

[0004] The object underlying the invention is to provide a safety valve unit with which the above disadvantages can be avoided, in particular a cost-effective and efficient safety valve unit is to be created.

[0005] This problem is solved by a safety valve unit, a refrigeration system, 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.

[0006] What is proposed is a safety valve unit for a refrigeration system of a motor vehicle, comprising a mechanically pressure-controlled valve stage which is configured to be opened as a function of a refrigerant pressure in order to allow refrigerant to temporarily escape from the refrigeration system when a predetermined refrigerant pressure in the refrigeration system is exceeded; a signal-controlled valve stage which is configured to be actuated as a function of an input signal in order to allow refrigerant to escape from the refrigeration system independently of the refrigerant pressure, wherein the safety valve unit is designed as an integrated component which is connectable or connected to a refrigerant line section and / or a functional component, in particular a refrigerant compressor or heat exchanger of the refrigeration system.

[0007] A safety valve unit designed in this way makes it possible for the mechanically pressure-controlled valve stage to be activated when excessive refrigerant pressure occurs, in order to release refrigerant and reduce the excess pressure. The first valve stage is closed again as soon as the refrigerant pressure returns to a lower level and the switching pressure falls below the first valve stage again. Overpressure management during normal operation of the motor vehicle or refrigeration system thus takes place without electronic monitoring and control. The second valve stage can be specifically controlled electronically if this is necessary, for example, due to one or more recorded vehicle parameters or vehicle operating parameters. The second valve stage can be actuated, for example, depending on signals from an impact sensor and / or a signal to inflate / deploy airbags or the like.The safety valve unit can therefore also be understood as a kind of robustness device for the refrigeration system.

[0008] In the safety valve unit, at least one spring element can be assigned to the first valve stage, which is configured to hold a first valve element of the first valve stage in a closed position as long as the refrigerant pressure falls below the predetermined level. In other words, the at least one spring element has a preload force acting on the first valve element, which counteracts a desired maximum pressure in the refrigeration system, but moves the valve element when the maximum pressure is exceeded to temporarily release refrigerant.

[0009] The safety valve unit can have an outlet line section whose line cross-section is closed by the first valve element as long as the refrigerant pressure falls below the predetermined level. The outlet line section can have or form a valve seat that is operatively connected to the first valve element.

[0010] In the safety valve unit, the first valve element can be designed as a piston-like plate or as a ball or as a cone.

[0011] In the safety valve unit, the second valve stage can have a support element on which the at least one spring element is supported, wherein the support element is movable relative to the first valve stage and / or removable from the safety valve unit upon actuation of the second valve stage. In other words, the second valve stage can be moved and / or removed independently of a pressure-controlled movement of the first valve stage.

[0012] The support element can be connected to the safety valve unit by means of a hinge device and held in a closed position by a locking device.

[0013] Furthermore, at least one second spring element can be assigned to the support element, which is pretensioned against the force of the locking device.

[0014] This makes it possible for the locking device to be released when the second valve stage is activated by signaling, thus releasing the support element. In combination with the optional second spring element, the support element can be opened with the aid of the acting spring force or rotated around the hinge relative to the safety valve unit.

[0015] In the safety valve unit, the second valve stage can be operatively connected to the first valve stage such that, upon actuation of the second valve stage, the preload force of the at least one spring element acting on the first valve element is reduced and / or eliminated. It is conceivable that a component supporting the preload force of the first spring element, in particular the support element, is removed or destroyed. Alternatively, it is also conceivable that the at least one spring element is destroyed or removed.

[0016] In the safety valve unit, the second valve stage can be arranged on a branch line section, whereby when the second valve stage is actuated, the branch line section is open and the first valve stage remains closed. In other words, the first valve stage and the second valve stage are arranged at different refrigerant outlets of the safety valve device, so that the refrigerant can escape through one or the other refrigerant outlet depending on the event (overpressure and / or damage event or collision).

[0017] Furthermore, a refrigeration system for a motor vehicle with a refrigerant circuit is proposed, wherein the refrigerant circuit comprises: a refrigerant compressor; at least one heat exchanger, in particular a gas cooler or condenser and an evaporator; and at least one safety valve unit as described above.

[0018] The at least one safety valve unit can be arranged on the high-pressure side and / or the low-pressure side on or in the refrigerant circuit.

[0019] In this context, it is also conceivable that the safety valve unit is directly or immediately connected to a functional component of the refrigeration system, in particular the refrigerant compressor or a heat exchanger or a refrigerant collector or the like, or is integrated therewith.

[0020] In addition to the usual function of cooling and / or dehumidifying a cabin supply air flow, the refrigeration system can also have a heat pump functionality for heating a cabin supply air flow.

[0021] Also proposed is a motor vehicle with an internal combustion engine and / or at least partially electric drive and with a refrigeration system as described above with at least one safety valve unit.

[0022] Further advantages and details of the invention will become apparent from the following description of embodiments with reference to the figures. Fig. 1 shows in the sub-figures A) to C) a simplified and schematic view of an example of a safety valve unit; Fig. 2 shows in the sub-figures A) to C) a simplified and schematic view of an example of a safety valve unit; Fig. 3 shows in the sub-figures A) to C) a simplified and schematic view of an example of a safety valve unit; Fig. 4 shows in the sub-figures A) to C) a simplified and schematic view of an example of a safety valve unit: Fig. 5 shows in the sub-figures A) to C) a simplified and schematic view of an example of a safety valve unit; Fig. Figure 6 shows a schematic and simplified view of a refrigeration system and possible positions for arranging a safety valve unit.

[0023] In Fig. 1, in the sub-figures A) to C) an example of a safety valve unit 50 for a refrigeration system of a motor vehicle is shown.

[0024] The safety valve unit 50 is connectable or connected to a refrigerant line section 52 (or a functional component of the refrigeration system).

[0025] The safety valve unit 50 has a mechanically pressure-controlled first valve stage V1, which is configured to open depending on a refrigerant pressure KD in order to temporarily release refrigerant from the refrigeration system when a predetermined refrigerant pressure in the refrigeration system is exceeded. When the set pressure or the predetermined refrigerant pressure is undershot, the first valve stage V1 closes again. Since this is a non-destructive, purely mechanical process, it can be replicated or executed multiple times if necessary, and can therefore be described as reversible between the closed and temporarily open states.

[0026] In the example shown, the pressure-controlled valve stage V1 comprises a piston-like plate as the valve element 54. The valve element 54 is held in a closed position by means of a first spring element 56, which in Fig. 1A is evident.

[0027] The safety valve unit 50 has an outlet line section 58 whose line cross-section is closed by the first valve element 54. In this example, the first valve element 54 cooperates with an associated sealing arrangement 59, such as an O-ring or the like.

[0028] The spring element 56 exerts a preload force that presses the first valve element 54 onto the outlet line section 58 or the sealing arrangement 59, respectively, and keeps the first valve stage V1 closed. In the example of Fig. 1, the spring element 56 is arranged above the valve element 54 and is suitably supported on the safety valve unit 50 in order to perform its function.

[0029] If an excessively high refrigerant pressure KD occurs in the refrigeration system or in the refrigerant line section 52 and thus also in the outlet line section 58, the valve element 54 is reversibly removed or lifted off the outlet line section 58 or the sealing arrangement 59 against the preload force of the spring element 56, so that refrigerant can escape, particularly laterally. This is Fig. 1B shown.

[0030] From the Fig. 1A to C) it can also be seen that the safety valve unit 50 has a signal-controlled second valve stage V2 which is designed to be actuated in response to an input signal.

[0031] This is simplified by an electronic device 60, such as a control device or the like, and a signal connection 61 illustrated in dash-dotted lines.

[0032] If the second valve stage V2 is actuated by signal control, which in the present example leads to a pyrotechnic destruction of the spring element 56, refrigerant can escape from the refrigeration system regardless of the refrigerant pressure KD.

[0033] From the Fig. 1 it is also apparent that the safety valve unit 50 with the two valve stages V1, V2 is designed as a combined, integrated component which can be connected to a refrigerant line section 52 and / or a functional component, in particular a refrigerant compressor or heat exchanger, of the refrigeration system or can be integrated into such a system.

[0034] From the Fig. 2 shows another example of the safety valve unit 50, which is essentially constructed in the same way as the safety valve unit 50 of the Fig. 1.

[0035] In contrast to Fig. 1, the spring element 56 of the first valve stage V1 is arranged below the valve element 54 in this example and is suitably supported on the safety valve unit 50 in order to perform its function.

[0036] The second valve stage V2 is as in Fig. 1 and when a corresponding signal is received from the electronic device 60, the spring element 56 is pyrotechnically destroyed so that the coolant can escape laterally.

[0037] Fig. 3 shows another example of the safety valve unit 50, which is similar to that of Fig. 1 is.

[0038] In this example, the valve element 54 is designed as a ball, which is arranged in a type of valve seat 62 on the outlet line section 58 to close the first valve stage V1. The valve element 54 is pressed onto or at least partially into the outlet line section by the preload force of the spring element 56. The spring element 56 is supported on a type of cover element 64 of the safety valve unit 50.

[0039] The second valve stage V2 has a Fig. 1 and Fig. 2 has a similar design and mode of operation. Upon receipt of a corresponding signal from the electronic device 60, the cover element 64 is pyrotechnically lifted and / or the spring element is destroyed or, due to the removal of the cover element 64 and thus the spring stop, is released, so that the effect of the preload force is canceled and refrigerant can escape laterally. To prevent the spring element 56 from possibly jumping out, it must be designed to be captive.

[0040] In Fig. 4 shows another example of the safety valve unit 50, which has a similar structure to that of the Fig. 3.

[0041] In the example of Fig. 4, the cover element 64 is connected to the safety valve unit 50 by means of a hinge 66. Furthermore, the cover element 64 is locked in a closed state ( Fig. 4A, Fig. 4B).

[0042] The cover element 64 is held in its closed position against the preload force of a second spring element 70.

[0043] When a corresponding signal is present from the electronic device 60, the lock 68 is released, so that the cover element 64 opens with the assisting force of the relaxing second spring element 70, so that refrigerant can escape laterally.

[0044] The example of Fig. 4 shows that the second valve stage V2 can also be designed reversibly without having to pyrotechnically destroy a component of the safety valve unit 50.

[0045] In a simplified embodiment, the second spring element 70 can be omitted and the first spring element 56 can be clamped directly against the cover element 64. Thus, the spring element 56 loses its stop immediately after the cover element 64 is opened, the preload force is reduced, and the refrigerant can escape via the outlet line section 58.

[0046] Fig. 5 shows another example of the safety valve unit 50, which is constructed in the same way with respect to the first valve stage V1 as in the example of Fig. 1.

[0047] In this example, the second valve stage V2 is arranged on a branch line section 72 which branches off from the outlet line section 58, wherein when the second valve stage V2 is actuated, the branch line section 72 is opened and the first valve stage V1 remains closed, which in Fig. 5C can be seen.

[0048] For everyone in the Fig. 1 to 5, it should be noted that in each case in part A) a closed state is shown, in part B) the escape of refrigerant is shown when the first valve stage V1 is opened by pressure control, and in Fig. C) the signal-controlled second valve stage V2 is shown.

[0049] In all examples of Fig. 1 to 4, the second valve stage V2 is designed such that it is operatively connected to the first valve stage V1 such that upon actuation of the second valve stage V2, the preload force of the at least one spring element 56 acting on the first valve element 54 is reduced and / or eliminated. In the event of an outflow, the refrigerant always uses the same outlet line section 58. Fig. 5, a further second outlet line section 72 is added, branching off from the outlet line section 58. Thus, the first valve stage V1 and the second valve stage V2 have different outlet positions for the refrigerant.

[0050] In the Fig. 1 to 5, the same reference numerals are used for similar components, without all components of the safety valve unit 50 being explicitly described in each figure.

[0051] In Fig. 6 shows a schematic and simplified representation of an embodiment of a refrigeration system 10 for a motor vehicle 200, shown here in simplified form as a rectangle.

[0052] The refrigeration system 10 comprises a refrigerant circuit 11, which in the embodiment shown has the following components: a refrigerant compressor 12, a first heat exchanger 18, in particular a gas cooler or condenser, a second heat exchanger 22, in particular an evaporator, a third heat exchanger 28, in particular a chiller, and an accumulator or refrigerant collector 24.

[0053] The evaporator 22 is shown here as an example of a front evaporator for a vehicle. The evaporator 22 also represents other possible evaporators in a vehicle, such as rear evaporators, which can be arranged parallel to one another in terms of flow. In other words, the refrigeration system 10 comprises at least one evaporator 22.

[0054] A shut-off valve A4 is located downstream of the compressor 12. An expansion valve AE2 is provided upstream of the evaporator 22.

[0055] For the purposes of this description, in the entire refrigerant circuit 11 of the refrigeration system 10, the section from the compressor 12 to the external heat exchanger 18, to an internal heat exchanger 20 and to the evaporator 22 is referred to as the primary line 14.

[0056] The refrigeration system 10 includes a heating register 26 (also referred to as a heating condenser or hot gas cooler) as a further heat exchanger. A shut-off valve A3 is arranged upstream of the heating register 26. A shut-off valve A1 is arranged downstream of the heating register 26. Furthermore, an expansion valve AE4 is arranged downstream of the heating register 26.

[0057] For the purposes of this description, the section of the entire refrigerant circuit of the refrigeration system 10 from the compressor 12 to the heating register 26, to the expansion valve AE4, and to a branch Ab2 is referred to as the secondary branch 16. The secondary branch 16 comprises a heating branch 16.1, which extends from the shut-off valve A3 via the heating register 26 to the shut-off valve A1. Furthermore, the secondary branch 16 comprises a reheat branch 16.2, which is fluidly connected upstream to the heating register 26 and downstream to the external heat exchanger 18. The secondary branch 16 or the reheat branch 16.2 flows into the primary branch 14 at a branch point Ab2.

[0058] The refrigeration system 10 includes the third heat exchanger, in particular a further evaporator or chiller 28. The chiller 28 is arranged in a fluidically parallel manner to the evaporator 22. The chiller 28 can serve, for example, to cool an electrical component of the vehicle, but also to implement a water heat pump function by utilizing the waste heat from at least one electrical component. An expansion valve AE1 is connected upstream of the chiller 28.

[0059] The refrigeration system 10 or the refrigerant circuit 11 also has the internal heat exchanger 20 as a further component.

[0060] In the Fig. 6 also shows various valve devices Ax (where x is a number), branches Aby (where y is a number), and sensors pTz (where z is a number) for detecting the pressure and / or temperature of the refrigerant, which are not discussed in detail here. However, such components of the refrigeration system 10 or the refrigerant circuit 11 are considered in combination with the information from the Fig. 6 in their position or function within the refrigeration system 10 as identifiable and disclosed, in particular due to the respective numbers (x, y, z) assigned to a respective prefix.

[0061] A decision referred to above with reference to the Fig. The safety valve unit 50 described in Figures 1 to 5 can be provided at different locations of the refrigeration system 10, which is indicated by a black triangle in the Fig. 6 is shown.

[0062] For example, positioning downstream of the refrigerant compressor 12 is conceivable, in particular in a refrigerant line section in which the highest refrigerant pressures are reached during normal operation of the refrigeration system 10.

[0063] Alternatively or additionally, a safety valve unit 50 described above can also be provided on the low-pressure side in the refrigeration system 10, for example downstream of the evaporator 22.

[0064] The provision of a safety valve unit 50 on both the high-pressure and low-pressure sides of the refrigeration system 10 makes it possible to avoid different overpressures for the high-pressure side (particularly during operation of the system) and the low-pressure side (particularly in the idle state) of the refrigeration system by means of the first valve stage V1. If the second valve stages V2 are triggered when two safety valve units 50 are provided in the refrigeration system 10, the refrigerant can escape very quickly from the entire refrigeration system. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2013 016 481 A1

[0002] DE 10 2014 004 957 A1

[0002] DE 10 2014 014 716 A1

[0002] WO 2007 087 992 A1

[0002] DE 10 2014 005 045 A1

[0002] DE 10 2015 214 307 A1

[0002]

Claims

[1] Safety valve unit (50) for a refrigeration system (10) of a motor vehicle (200) with a mechanically pressure-controlled first valve stage (V1) which is designed to be opened as a function of a refrigerant pressure in order to allow refrigerant to temporarily escape from the refrigeration system (10) when a predetermined refrigerant pressure in the refrigeration system (10) is exceeded, a signal-controlled second valve stage (V2) which is designed to be actuated in response to an input signal in order to allow refrigerant to escape from the refrigeration system (10) independently of the refrigerant pressure, wherein the safety valve unit (50) is designed as an integrated component that can be connected or is connected to a refrigerant line section (52) and / or a functional component, in particular a refrigerant compressor or heat exchanger of the refrigeration system (10). [2] Safety valve unit (50) according to claim 1, wherein the first valve stage (V1) is assigned at least one spring element (56) which is designed to hold a first valve element (54) of the first valve stage (V1) in a closed position as long as the predetermined refrigerant pressure is undershot. [3] Safety valve unit (50) according to claim 2, wherein it comprises an outlet line section (58) whose line cross-section is closed by the first valve element (54) as long as the predetermined refrigerant pressure is not reached. [4] Safety valve unit (50) according to claim 2 or 3, wherein the first valve element (54) is designed as a piston-like plate or as a ball or as a cone. [5] Safety valve unit (50) according to one of the preceding claims, wherein the second valve stage (V2) has a support element (64) on which the at least one spring element (56) is supported, wherein the support element (64) is movable relative to the first valve stage (V1) and / or removable from the safety valve unit (50) upon actuation of the second valve stage (V2). [6] Safety valve unit (50) according to claim 5, wherein the support element (64) is connected to the safety valve unit (50) by means of a hinge device (66) and is held in a closed position by a locking device (68), wherein preferably the support element (64) is assigned at least one second spring element (70) which is prestressed against the force of the locking device (68). [7] Safety valve unit (50) according to one of claims 2 to 6, wherein the second valve stage (V2) is operatively connected to the first valve stage (V1) in such a way that upon actuation of the second valve stage (V2), the prestressing force of the at least one spring element (56) acting on the first valve element (54) is reduced and / or dissipated. [8] Safety valve unit (50) according to one of claims 1 to 3, wherein the second valve stage (V2) is arranged on a branch line section (72), wherein when the second valve stage (V2) is actuated, the branch line section (72) is opened and the first valve stage (V1) remains closed. [9] Refrigeration system (10) for a motor vehicle (200) with a refrigerant circuit (11), wherein the refrigerant circuit (11) comprises: a refrigerant compressor (12); at least one heat exchanger (18, 22, 26, 28), in particular a gas cooler or condenser and an evaporator; and at least one safety valve unit (50) according to one of the preceding claims. [10] Motor vehicle (200) with internal combustion engine and / or at least partially electric drive and with a refrigeration system (10) according to claim 9.

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