Flow control valve for refrigeration circuits with overpressure function

Abstract

Valve, in particular expansion valve, (22) for a thermal management system, preferably a thermal management system according to the present invention, comprising at least one pressure relief valve (5) that is configured such that - to open to an open position and release fluid when a predetermined pressure difference is exceeded between a first pressure on an inlet side (51) of the pressure outlet valve (5) and a second pressure on an outlet side (52) of the pressure outlet valve (5). to close in a closed position and seal against the flow of fluid when the predetermined pressure difference is undershot.

Description

[0001] The present invention relates to a valve, in particular an expansion valve, for a thermal management system, a thermal management system, in particular for a vehicle, in particular an electric or hybrid vehicle, a building and a vehicle comprising the said thermal management system.

[0002] With the increasing prevalence of electric and hybrid vehicles, the demands on the safety, efficiency, compactness, and cost of the systems and components used are also rising. Particularly in thermal management—that is, the temperature control of consumers within the vehicle—and the associated management of thermal loads, the tightness of the cooling or refrigerant circuits is playing an increasingly important role.

[0003] The thermal management system in electric or hybrid vehicles not only serves to climate-control the passenger compartment. In particular, the battery and other electrical components are also temperature-controlled by the thermal management system.

[0004] In comparison to conventional combustion engine vehicles, the new thermal management systems for electric or hybrid vehicles must be significantly more sealed, almost hermetically sealed, in order to prevent the loss of fluids, such as refrigerant, in a refrigerant circuit of a heat pump, for example, and to ensure the efficiency and safety of the thermal management system.

[0005] Existing state-of-the-art solutions employ separate pressure relief valves or rupture discs. However, these are often not sufficiently leak-proof or can even lead to uncontrolled pressure increases, endangering the system and especially the compressor. Furthermore, rupture discs are designed to rupture under excessive pressure and remain open after activation, typically resulting in costly and time-consuming repairs.

[0006] Therefore, one of the problems underlying the invention is to overcome the aforementioned problems and to provide a thermal management system that is improved compared to the prior art, especially for electric or hybrid vehicles.

[0007] Another objective underlying the invention is to provide a thermal management system that is able to ensure the safety of thermal management systems in overpressure situations in the refrigerant circuit, despite almost hermetic sealing.

[0008] These and other problems are solved by the subject matter of the attached independent claims. Preferred embodiments can be found in the dependent claims and furthermore in the following description, which in particular includes various embodiments as described in the attached claims.

[0009] The person skilled in the art will understand that each embodiment described in the following description is covered and encompassed by the subject matter of the appended claims. The embodiments, features, and combinations of features described herein in connection with the invention, as well as the combinations of features specified in the appended claims, and also any combination of features mentioned and described in connection with the embodiments, are deemed to be disclosed herein, or at least to be derivable by the person skilled in the art. In particular, each feature and each combination of features in the embodiments described herein may, for example, be claimed in a different combination, particularly in a different category of claims, at least because the person skilled in the art will recognize that each combination of the features mentioned herein is suitable for solving the underlying problem.Furthermore, any feature and any combination of features in the claims and in the description below can be used and claimed independently of the specific claimed subject matter, independent of claim dependencies and cross-references, and independent of the claim category in which the feature is claimed. For example, it can be provided in any combination selected from one or more claims, one or more of the embodiments listed below, and / or the accompanying figures.

[0010] The problems described above are advantageously solved in a first aspect by a thermal management system according to the present invention. This thermal management system is particularly useful when used in a vehicle, especially an electric or hybrid vehicle. The thermal management system according to the invention comprises a first refrigerant circuit, which includes a cooling system, in particular a heat pump system with at least one compressor, a first heat exchanger, in particular an evaporator, optionally a second heat exchanger, in particular a condenser, and an expansion valve.

[0011] In a second aspect, the problems described above are advantageously solved by a valve, in particular an expansion valve, according to the present invention. Such a valve, in particular an expansion valve, can be particularly advantageously used in a thermal management system, in particular a thermal management system according to the present invention. The valve according to the invention is preferably an expansion valve; however, the function underlying the present invention can also be advantageously implemented in other valves. A valve according to the present invention is preferably an expansion valve, a shut-off valve (on-off valve), or optionally a changeover valve, which is preferably integrated into the refrigerant circuit of a thermal management system.

[0012] A thermal management system is a system that regulates the temperature of at least two devices. A device is therefore a unit that needs to be cooled or heated. One device can be for cooling and the other for heating. These devices can even be part of the same cooling circuit, as will be explained below. Similarly, a device can also be a component in building services, such as a heating system, or in industrial plants.

[0013] In the present invention, temperature control is understood to mean cooling or heating.

[0014] Preferably, a consumer can be an electric machine. Furthermore, a consumer can be an inverter. Additionally or alternatively, a consumer can be a passenger compartment. Advantageously, a consumer can be a battery.

[0015] The thermal management system comprises at least one coolant circuit. Preferably, the thermal management system comprises at least one refrigerant circuit and one coolant circuit. Furthermore, the thermal management system can comprise at least two, and in particular exactly two, coolant circuits and one refrigerant circuit.

[0016] The refrigerant circuit contains at least one cooling device. This device cools the refrigerant. The refrigerant circuit is temperature-controlled via the refrigerant and is in direct contact with the consumers.

[0017] Preferably, one of the coolant circuits can be arranged as a high-temperature circuit and the other as a low-temperature circuit. The high-temperature circuit is thermally connected to the refrigerant circuit at a first point, and the low-temperature circuit at a second point. The first point has a higher temperature than the second point. In particular, the high-temperature circuit can be connected to the refrigerant circuit downstream of a compressor. Preferably, the low-temperature circuit can be connected to the refrigerant circuit downstream of an expansion valve.

[0018] The cooling system can be designed as a heat pump. The heat pump comprises at least one, preferably two, heat exchangers and a compressor. One of the heat exchangers can be designed as a condenser and the other as an evaporator.

[0019] Preferably, the first coolant circuit is a low-temperature circuit, in particular a cooling water circuit, which flows through a first heat exchanger, in particular an evaporator.

[0020] Preferably, the second coolant circuit is a high-temperature circuit that flows through a second heat exchanger, in particular a compressor.

[0021] The temperature to which the high-temperature circuit is cooled can be, for example, 40°C. This temperature can be used simultaneously to heat one component, such as the passenger compartment, and to cool another component, such as an electric motor.

[0022] The low-temperature circuit is cooled to a lower temperature than the high-temperature circuit. This allows the cooling capacity to be concentrated on the low-temperature circuit, to which the largest cooling load, such as power electronics, is connected. This optimizes the provision of cooling capacity and allows, for example, the compressor to be smaller.

[0023] A radiator can preferably be arranged in the low-temperature circuit.

[0024] Advantageously, a passenger compartment and / or an electric motor and / or a battery can be arranged as consumers in the high-temperature circuit. Furthermore, a power electronics assembly, in particular an inverter, can be arranged in the low-temperature circuit.

[0025] Preferably, the refrigerant in the refrigerant circuit is a natural refrigerant, in particular propane. Alternatively, the coolant in the cooling circuit(s) can be a water-glycol mixture.

[0026] Preferably, the thermal management system includes a distribution unit. The distribution unit controls which circuit is connected to which other circuit and which consumer. The distribution unit is also referred to as a Fluid Control Unit (FCU). Advantageously, the distribution unit includes a valve unit with at least one valve. The valve can be a spool valve, in particular an axial spool valve or a rotary spool valve. In particular, the valve unit can have at least four, preferably exactly four, valves.

[0027] The distribution unit can have at least two housing parts. Channel structures and / or valve mounting areas can be formed on the adjacent sides of the housing parts. Alternatively, one housing part can be designed as a cover without any structures, and only one housing part can have channel structures and / or valve mounting areas. It is also conceivable to provide only valve mounting areas in one housing part and only channel structures in the other housing part.

[0028] Furthermore, the thermal management system comprises a pump arrangement with at least one pump. Preferably, the pump arrangement can comprise at least two, and in particular exactly two, pumps. At least one pump can be designed as a gerotor pump. At least one pump can be designed as a vane pump.

[0029] Alternatively, the thermal management system can also be installed in a stationary position, e.g., in a building. Consumers in this case might be household or industrial equipment, such as heating systems.

[0030] The problems mentioned above are also advantageously solved in a third aspect of the present invention by a motor vehicle, in particular an electric or hybrid vehicle, which comprises a thermal management system and / or a valve, in particular an expansion valve, according to the present invention.

[0031] In this context, the integration of the thermal management system according to the present invention into a vehicle, in particular an electric or hybrid vehicle, offers significant technical advantages, including improved efficiency, reduced complexity and weight, improved cooling performance, simplified maintenance and increased safety.

[0032] The problems mentioned above are also advantageously solved in a fourth aspect of the present invention by a building comprising a thermal management system and / or a valve, in particular an expansion valve, according to the present invention.

[0033] The central feature of the invention is that the valve, in particular the expansion valve, the thermal management system, or the building or motor vehicle according to the present invention has a pressure relief valve. This pressure relief valve according to the invention is arranged in the refrigerant circuit of the thermal management system or is configured to be arranged in the refrigerant circuit of the thermal management system. In particular, a valve, especially an expansion valve, for a thermal management system according to the second aspect of the present invention comprises such a pressure relief valve.

[0034] The term “inlet side of the pressure outlet valve”, as used herein, preferably refers to the high-pressure side of the refrigerant circuit within the scope of the present invention.

[0035] The term “outlet side of the pressure relief valve”, as used herein, preferably refers to the low-pressure side of the refrigerant circuit within the scope of the present invention.

[0036] It is therefore preferably the pressure relief valve is arranged or configured such that the inlet side of the pressure relief valve is a high-pressure side of the refrigerant circuit and / or the outlet side of the pressure relief valve is a low-pressure side of the refrigerant circuit.

[0037] According to the invention, the pressure relief valve is designed and arranged such that when a predetermined pressure difference between a first pressure on an inlet side of the pressure relief valve and a second pressure on an outlet side of the pressure relief valve is exceeded, the pressure relief valve opens to an open position and a fluid, preferably the refrigerant of the refrigerant circuit, is released. Furthermore, when the predetermined pressure difference falls below the threshold, the pressure relief valve closes to a closed position and is thus sealed against the flow of fluid.

[0038] A person skilled in the art will immediately recognize that a feature, embodiment, effect or advantage described herein in connection with the pressure relief valve according to the invention may, individually, simultaneously or alternatively, be a feature, embodiment, effect or advantage of the thermal management system according to the invention, the valve according to the invention, in particular the expansion valve, and / or the motor vehicle according to the invention.

[0039] Within the present application, terms such as "side" or "lateral", "rear", "front", "top", "bottom", "ground", "opposite", "inside", "outside" or the like, which describe the position of a first object relative to another object, preferably refer to the relative position of each respective part or object in relation to its position when it is fully assembled for its intended use.

[0040] In a preferred embodiment of the valve according to the invention, in particular the expansion valve, and / or the thermal management system according to the invention and / or the motor vehicle according to the invention, the pressure relief valve has a movable valve element, wherein the valve element is movable between the closed position, in which the inlet side is separated from the outlet side, preferably fluidically separated, and the open position, in which the inlet side is fluidically connected to the outlet side.

[0041] This is particularly advantageous because the movable valve element in the pressure relief valve allows for precise control of the fluid flow. In the closed position, the inlet side is fluidically isolated from the outlet side, preventing uncontrolled refrigerant escape. This helps maintain the desired pressure level in the refrigerant circuit and ensures efficient cooling. In the open position, however, the inlet side is fluidically connected to the outlet side, allowing excess refrigerant to be released quickly and in a controlled manner. This protects the system from overpressure and potential damage, increasing the reliability and longevity of the thermal management system.

[0042] In a further preferred embodiment of the valve and / or the thermal management system and / or the motor vehicle according to the invention, the pressure outlet valve has a valve seat which forms a stationary surface against which, in the closed position, a movable valve element seals the flow of the fluid.

[0043] This is particularly advantageous because the valve seat, as a stationary surface, ensures a reliable and stable seal. In the closed position, the movable valve element presses against the valve seat, effectively preventing fluid flow. This design minimizes the risk of leaks and ensures precise pressure control within the system. This increases the efficiency and safety of the thermal management system by preventing unwanted pressure losses and protecting the system from potential damage caused by uncontrolled fluid flow.

[0044] In a further preferred embodiment of the expansion valve and / or the thermal management system and / or the motor vehicle according to the invention, in the closed position of the pressure relief valve, the valve element is pressed against the valve seat by means of a contact force, thus preventing the flow of fluid. For this purpose, a force element, e.g., a spring, can advantageously be provided to transmit the contact force, which presses the valve element against the valve seat by means of the contact force.

[0045] This is particularly advantageous because the contact force pressing the valve element against the valve seat ensures a reliable and permanent, yet reversible, seal. This effectively prevents fluid flow in the closed position.

[0046] When the pressure differential falls below the predetermined threshold, the pressure relief valve is preferably closed and sealed against fluid flow by pressing the valve element against the valve seat using a clamping force. When the predetermined pressure differential between the first pressure on the inlet side of the pressure relief valve (preferably the pressure of the refrigerant in the refrigerant circuit) and the second pressure on the outlet side of the pressure relief valve is exceeded, the valve opens to an open position, allowing a fluid, preferably refrigerant, to flow from the high-pressure side to the low-pressure side. This clamping force is preferably passive and is overcome essentially only by the pressure generated by exceeding the predetermined pressure differential, thus opening the pressure relief valve to an open position.In particular, on the inlet side of the pressure relief valve, the pressure of the refrigerant in the refrigerant circuit can, when the predetermined pressure difference is exceeded, press the valve element against the contact force from the valve seat, allowing the refrigerant to escape until the predetermined pressure difference is reached again.

[0047] In a further preferred embodiment of the expansion valve and / or the thermal management system and / or the motor vehicle according to the invention, the pressure outlet valve has a spring which is arranged such that, in a closed position of the pressure outlet valve, the valve element is pressed against the valve seat by means of a contact force mediated by the spring, so that the flow of fluid is prevented.

[0048] This is particularly advantageous because the spring exerts a constant and reliable contact force, especially the spring force, on the valve element, thereby ensuring an effective seal against the valve seat.

[0049] In a further preferred embodiment of the expansion valve and / or the thermal management system and / or the motor vehicle according to the invention, the contact force of the valve element is arranged such that, when the predetermined pressure differential is exceeded, the valve element is moved against the contact force into the open position. In other words, when the predetermined pressure differential in the refrigerant circuit on the high-pressure side of the pressure outlet valve is exceeded, the valve element is moved against the contact force, in particular the spring force of a spring, into the open position, and thus fluid, in particular refrigerant from the refrigerant circuit, flows from the high-pressure side to the low-pressure side.

[0050] This is particularly advantageous if the spring force or the contact force of the valve element is set such that the force-transmitting element, especially the spring, yields when the predetermined pressure differential is exceeded, and the valve element is moved into the open position. This enables automatic pressure equalization in the system, which reduces the risk of overpressure and associated damage.

[0051] While the contact force is essentially overcome passively by the pressure when it is exceeded, thereby moving the valve element into the open position and bringing the pressure relief valve into the open position, the present invention preferably also considers actively controlling the opening and / or closing of the pressure relief valve.

[0052] In a further preferred embodiment of the expansion valve and / or the thermal management system and / or the motor vehicle according to the invention, the pressure relief valve comprises a drive means, preferably an electric drive, preferably comprising an electric motor and / or an electromagnet, which is configured to open the pressure relief valve to the open position and release fluid.

[0053] Simultaneously or alternatively, the drive mechanism can be configured to close the pressure relief valve to the closed position.

[0054] This is particularly advantageous because the drive mechanism, for example an electric actuator such as an electric motor or electromagnet, enables precise and rapid control of the pressure relief valve. By using a drive mechanism, the valve can be moved in a controlled manner to the open position to discharge excess fluid or to precisely adjust the system's flow rate.

[0055] The drive mechanism can be an electric drive, such as an electric motor or electromagnet, but any other type of suitable drive mechanism, such as a pneumatic, hydraulic or electric drive, can also be used to advantage.

[0056] In a further preferred embodiment of the expansion valve and / or the thermal management system and / or the motor vehicle according to the invention, the drive means is arranged to open the pressure outlet valve and to move the valve element against the contact force into the open position.

[0057] This is particularly advantageous because the pressure relief valve can be opened in a controlled manner using the drive mechanism. In one embodiment, the pressure relief valve can be adjusted between two positions: an open position and a closed position. Alternatively, stepless adjustment of the valve can be achieved, for example, by a drive mechanism in the form of a linear motor or electromagnet in conjunction with the spring and pressure, allowing for even more precise control of the pressure release.

[0058] A particularly advantageous feature of a pressure relief valve is its automatic closure when de-energized, i.e., in the event of a power failure or when the drive mechanism is without power. This can be achieved, in particular, by pressing the valve element against the valve seat using a contact force. In other words, the pressure relief valve is a so-called "normally closed" valve.

[0059] This ensures that the valve remains in a safe, closed position when no electrical power is available. Conversely, the electric drive overcomes the contact force to open the valve.

[0060] This means that the pressure relief valve closes automatically in the event of a power failure, i.e., if the drive medium is without power or the drive medium itself is defective, while at the same time fluid can still be released if the predetermined pressure difference is exceeded.

[0061] In a further preferred embodiment of the expansion valve and / or the thermal management system and / or the motor vehicle according to the invention, the valve comprises the pressure relief valve. The pressure relief valve can also be designed as a part, in particular an integral part, of the expansion valve.

[0062] This is particularly advantageous because the integration of the pressure relief valve allows for a more compact and efficient design of the valve, especially the expansion valve. Integrating the pressure relief valve as a part, and especially as an integral part, of the expansion valve reduces the number of components and connections required, thus increasing the reliability and ease of maintenance of the system. Furthermore, the compact design saves space and reduces the weight of the entire thermal management system or vehicle, resulting in improved energy efficiency and performance.

[0063] In a further preferred embodiment of the expansion valve and / or the thermal management system and / or the motor vehicle according to the invention, the predetermined pressure differential is at most 100 bar, preferably at most 75 bar, and more preferably at most 50 bar. Simultaneously or alternatively, the predetermined pressure differential is at least 15 bar, preferably at least 25 bar, and more preferably at least 30 bar. Simultaneously or alternatively, the predetermined pressure differential is between at least 15 bar and at most 100 bar, preferably between at least 25 bar and at most 50 bar, and even more preferably between at least 30 bar and at most 35 bar.

[0064] It should also be understood and acknowledged that a skilled person knows various ways to adjust the predetermined pressure differential so that the valve opens at a specific pressure difference. For example, the contact pressure, particularly spring tension, and / or the opening area can be dimensioned differently. The selected predetermined pressure differential depends on the refrigerant and on the design of the components of the entire thermal management system.

[0065] In a further preferred embodiment of the expansion valve and / or the thermal management system and / or the motor vehicle according to the invention, the pressure outlet valve is selected from the group comprising cone valve and plate valve.

[0066] This is particularly advantageous because the pressure relief valve, whether a cone or plate valve, allows for flexible adaptation to different operating conditions and requirements within the thermal management system. Cone valves offer precise control and tightness, which is especially beneficial under varying pressure conditions. Plate valves, on the other hand, are characterized by their robustness and simple design, improving maintenance and extending the system's lifespan.

[0067] In a further preferred embodiment of the expansion valve and / or the thermal management system and / or the motor vehicle according to the invention, the valve element is arranged on the outlet side of the pressure relief valve. Preferably, the outlet side is provided and / or configured as a low-pressure side of the refrigerant circuit.

[0068] This is particularly advantageous because arranging the valve element on the outlet side of the pressure relief valve allows for efficient control of the refrigerant flow. Positioning it on the low-pressure side of the refrigerant circuit minimizes the pressure drop across the valve, thus increasing the system's energy efficiency. BRIEF DESCRIPTION OF THE FIGURES

[0069] The present invention is explained in more detail below with reference to the drawings, from which further features, embodiments, and advantages can be derived. In the embodiments shown in the figures, elements that have similar or identical functions are designated with the same reference numerals. It should be noted that the figures may not be to scale.

[0070] This shows: Fig. 1. A schematic flowchart of a state-of-the-art thermal management system; Fig. 2A and Fig. 2B a schematic representation of the pressure relief valve according to the present invention in an open position ( Fig. 2A) and in a closed position ( Fig. 2B). DETAILED DESCRIPTION

[0071] The features of the present invention disclosed in the description, claims, examples, and / or figures can be essential for realizing the invention in various embodiments, both individually and in any combination. In the embodiments shown in the figures, elements with similar or identical functions are provided with the same reference numerals. It should be noted that the figures may not be to scale.

[0072] Fig. Figure 1 shows a state-of-the-art thermal management system that can be used particularly in standard combustion engine vehicles. Such a thermal management system typically comprises a refrigerant circuit 2 with a cooling system 1, such as a heat pump system 1 in this case. The heat pump 1 operates by compressing the refrigerant with the compressor 21, thereby increasing the pressure and temperature of the refrigerant.

[0073] The compressor 21 is driven by an electric machine 25. The heated refrigerant then flows through a second heat exchanger 24, in particular a condenser 24, where it releases heat to the high-temperature circuit 4 and condenses into a liquid. The liquid refrigerant then passes through an expansion valve 22, which in the prior art does not have a pressure relief valve 5 according to the invention, where it experiences a pressure drop and cools down considerably. The cooled refrigerant then enters a first heat exchanger 23, in particular an evaporator 23, where it absorbs heat from the low-temperature circuit 3, causing it to evaporate and complete the circuit.

[0074] This means that in this example there are two coolant circuits, 3 and 4. The first coolant circuit, 3, which is the low-temperature circuit, specifically a cooling water circuit, allows the coolant to flow through the evaporator 23. This circuit 3 is responsible for the refrigerant in circuit 2 absorbing heat from the coolant in the low-temperature circuit 3, thereby cooling the coolant in circuit 3, which can then cool the consumers connected to this circuit 3. The second coolant circuit, 4, which is a high-temperature circuit 4, allows the coolant to flow through the condenser 24. This circuit is designed to transfer the heat from the refrigerant in circuit 2 to the high-temperature circuit 4, thus warming and heating the consumers connected to the high-temperature circuit 4. In this case, the high-temperature circuit 4 can include an additional heater 41, for example.a PTC heater 41.

[0075] Fig. 2A and Fig. Figure 2B shows schematic representations of a pressure relief valve 5, which is a component of a thermal management system according to the present invention or of an expansion valve 22 according to the present invention. In particular, a pressure relief valve 5 according to the invention can be incorporated into a, as shown in Fig. 1. The thermal management system shown is state-of-the-art and will be integrated.

[0076] Essentially, it shows Fig. 2 schematically the structure of a first embodiment of the pressure relief valve 5, namely in Fig. 2A in an open position and in Fig. 2B in a closed position.

[0077] It should be understood that the thermal management system according to the present invention may, in particular, comprise a valve in the form of an expansion valve 22 according to the second aspect of the present invention. The thermal management system then comprises the pressure relief valve as part of the expansion valve, in particular as an integral part, of the expansion valve 22.

[0078] Simultaneously or alternatively, the thermal management system according to the present invention can comprise a pressure relief valve as described herein in addition to the expansion valve 22.

[0079] The expansion valve 22 according to the second aspect of the invention is suitable for a thermal management system, in particular for an electric or hybrid motor vehicle, and is preferably suitable for a thermal management system according to the first aspect of the present invention.

[0080] In the illustrated embodiment, the pressure relief valve 5 is designed as part of the expansion valve 22 and is arranged in the refrigerant circuit 2, such that the inlet side 51 of the pressure relief valve 5 is fluidically connected to the refrigerant line of the refrigerant circuit 2. The valve element 54 is arranged on the outlet side 52 of the pressure relief valve 5, which corresponds to the low-pressure side of the refrigerant circuit 2.

[0081] The illustrated pressure relief valve 5 is designed to open when a predetermined pressure difference is exceeded between a first pressure on an inlet side 51 of the pressure relief valve 5 and a second pressure on an outlet side 52 of the pressure relief valve 5, as shown in Fig. 2A shows the opening and the release of fluid, as indicated by the dotted arrows. If the predetermined pressure differential is undershot, the pressure relief valve 5 closes in a closed position, as shown in Fig. 2B is shown and thus seals against the flow of fluid.

[0082] For this purpose, the pressure outlet valve 5 has a movable valve element 54 which can be moved between the closed position in Fig. 2B, in which the inlet side 51 is separated from the outlet side 52, and the open position in Fig. 2A, in which the inlet side 51 is fluidically connected to the outlet side 52, is movable.

[0083] The pressure relief valve 5 has in particular a valve seat 53 which forms a stationary surface against which, in the closed position, the movable valve element 54 seals the flow of the fluid, which is particularly advantageous in Fig. 2B is evident through the contact surface between valve element 54 and valve seat 53.

[0084] In the closed position of the pressure relief valve 5 in Fig. In 2B, the valve element 54 is pressed against the valve seat 53 by means of a contact force 55, thus preventing the flow of fluid. For this purpose, the Fig. 2A and Fig. Figure 2B shows a pressure relief valve 5 with a spring 56, which is arranged such that, in the closed position of the pressure relief valve 5, the valve element 54 is pressed against the valve seat 53 by means of the contact force 55 mediated by the spring 56, thus preventing the flow of fluid. The contact force 55 of the valve element 54, or in this case the spring force of the spring 56, is set such that if the predetermined pressure difference is exceeded, the valve element 54 is forced into the open position against the contact force 55. Fig. 2A is being moved.

[0085] The in Fig. 2A and Fig. The pressure relief valve 5 shown in Figure 2B has an additional actuator 57, for example, an electric actuator 57, which for the sake of simplicity is shown here only as a force arrow indicating the force transmitted by the actuator 57. Such an actuator can, for example, include an electric motor and / or an electromagnet. The actuator 57 can open the pressure relief valve 5 to the open position and thus release fluid. In other words, the actuator 57 is configured to move the valve element 54 between the closed position and the open position. Fig. 2B and the open position in Fig. 2A to move, but at least from the closed position into Fig. 2B into the open position in Fig. 2A to open. This means that even without a predetermined pressure difference being reached, refrigerant can be released from the refrigerant circuit 2 in a controlled manner by means of the actuator 57 when it opens the pressure relief valve 5. For this purpose, the actuator 57 is designed to open the pressure relief valve 5 and to move the valve element 54 against the contact force 55, here against the spring 56, into the open position. Fig.2A to move. The pressure relief valve 5 is particularly preferably configured to close automatically when de-energized, i.e., in the event of a power failure or when the actuator 57 is without power. This can be achieved, in particular, by pressing the valve element 54 against the valve seat 53 by means of the contact force 55. Thus, the pressure relief valve is in the "normally closed" position unless the actuator 57 actively lifts the valve element 54 from the valve seat 53, or unless the predetermined pressure differential is exceeded. The valve is therefore in a safe, closed position even when no electrical energy is available at the actuator 57; however, the contact force 55 can simultaneously be overcome by pressure when the predetermined pressure differential is exceeded, in order to open the valve.

[0086] The embodiments shown in the figures may refer to preferred embodiments, while all elements and features described in connection with embodiments may, where appropriate, be used in combination with any other embodiment and any other feature as described herein, in particular with respect to any other embodiment discussed above. Reference sign 1 Cooling system, heat pump system 2 first refrigerant circuit 21 Compressor 22 Expansion valve 23 evaporators 24 Capacitor 25 Electric machine 3 Low-temperature circuit, first coolant circuit 4. High-temperature circuit, second coolant circuit 41 PTC heaters 5 Pressure relief valve 51 Inlet, high pressure side 52 Outlet, low-pressure side 53 Valve seat 54 Valve element 55 Contact force 56 spring 57 electric drive

Claims

[1] Valve, in particular expansion valve, (22) for a thermal management system, comprising at least one pressure outlet valve (5) that is configured such that - to open to an open position and release fluid when a predetermined pressure difference is exceeded between a first pressure on an inlet side (51) of the pressure outlet valve (5) and a second pressure on an outlet side (52) of the pressure outlet valve (5). to close in a closed position and seal against the flow of fluid when the predetermined pressure difference is undershot. [2] Thermal management system, in particular for a vehicle, in particular an electric or hybrid vehicle, comprising: a first refrigerant circuit (2) comprising a cooling system (1), in particular a heat pump system (1), with ◯ at least one compressor (21), ◯ a first heat exchanger (23), in particular an evaporator (23), ◯ optionally a second heat exchanger (24), in particular a condenser (24), and ◯ an expansion valve (22), preferably an expansion valve which is a valve according to claim 1, optionally, a first coolant circuit, which is a low-temperature circuit (3), in particular a cooling water circuit, which flows through the first heat exchanger (23), in particular the evaporator (23), optionally, a second coolant circuit, which is a high-temperature circuit (4), which flows through the second heat exchanger (24), in particular the condenser (24), and more comprehensive • at least one pressure relief valve (5) arranged and installed in the refrigerant circuit (2), ◯ to open to an open position and release a fluid, preferably refrigerant from the refrigerant circuit (2), when a predetermined pressure difference between a first pressure on an inlet side (51) of the pressure outlet valve (5) and a second pressure on an outlet side (52) of the pressure outlet valve (5) is exceeded and ◯ to close in a closed position and seal against the flow of fluid when the predetermined pressure difference is undershot. [3] Valve, in particular expansion valve, (22) or thermal management system according to claim 1 or 2, wherein the pressure outlet valve (5) has a movable valve element (54), wherein the valve element (54) is movable between the closed position in which the inlet side (51) is separated from the outlet side (52) and the open position in which the inlet side (51) is fluidically connected to the outlet side (52). [4] Valve, in particular expansion valve, (22) or thermal management system according to one of the preceding claims, wherein the pressure outlet valve (5) has a valve seat (53) which forms a stationary surface against which, in the closed position, a movable valve element (54) seals the flow of the fluid. [5] Valve, in particular expansion valve, (22) or thermal management system according to claim 4, wherein in the closed position of the pressure outlet valve (5) the valve element (54) is pressed against the valve seat (53) by means of a contact force (55) so that the flow of the fluid is prevented. [6] Valve, in particular expansion valve, (22) or thermal management system according to claims 4 or 5, wherein the pressure outlet valve (5) has a spring (56) which is arranged such that in a closed position of the pressure outlet valve (5) the valve element (54) is pressed against the valve seat (53) by means of a contact force (55) mediated by the spring (56), so that the flow of the fluid is prevented. [7] Valve, in particular expansion valve, (22) or thermal management system according to one of the preceding claims, wherein the contact force (55) of the valve element (54) is arranged such that when the predetermined pressure difference is exceeded, the valve element (54) is moved against the contact force (55) into the open position. [8] Valve, in particular expansion valve, (22) or thermal management system according to one of the preceding claims, wherein the pressure outlet valve (5) comprises a drive means (57), preferably an electric drive (57), preferably comprising an electric motor and / or an electromagnet, which is configured to open the pressure outlet valve (5) to the open position and discharge fluid. [9] Valve, in particular expansion valve, (22) or thermal management system according to claim 8, wherein a drive means (57) is configured to open the pressure outlet valve (5) and to move the valve element (54) against the contact force (55) into the open position. [10] Valve, in particular expansion valve, (22) or thermal management system according to one of the preceding claims, wherein the valve, in particular expansion valve, (22) comprises the pressure outlet valve (5), preferably the pressure outlet valve (5) is designed as a part, in particular an integral part, of the valve, in particular expansion valve, (22). [11] Valve, in particular expansion valve, (22) or thermal management system according to one of the preceding claims, wherein the predetermined pressure is at most 100 bar, preferably at most 75 bar, more preferably at most 50 bar and / or at least 15 bar, preferably at least 25 bar, more preferably at least 30 bar and / or between at least 15 bar and at most 100 bar, preferably between at least 25 bar and at most 50 bar and even more preferably between at least 30 bar and at most 35 bar. [12] Valve, in particular expansion valve, (22) or thermal management system according to any of the preceding claims, wherein the pressure outlet valve (5) is selected from the group comprising cone valve and plate valve. [13] Valve, in particular expansion valve, (22) or thermal management system according to one of the preceding claims, wherein the valve element (54) is arranged on the outlet side (52) of the pressure outlet valve (5), and preferably the outlet side (52) is provided and / or designed as a low-pressure side of the refrigerant circuit (2). [14] Motor vehicle, in particular electric or hybrid vehicle, comprising a thermal management system and / or a valve, in particular an expansion valve, (22) according to any of the preceding claims. [15] Building comprising a thermal management system and / or a valve, in particular an expansion valve, (22) according to any one of claims 1 to 13.

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