Emergency cooling of liquid cooled systems

Abstract

A liquid-cooled system includes a primary cooling circuit intended to circulate a cooling fluid in order to dissipate heat from a heat source. A cold plate assembly is thermally coupled with the heat source, facilitating heat exchange with the cooling liquid. In emergency situations where a conventional cooling circuit may fail, the system activates an emergency cooling unit that includes a phase change material (PCM) housed within a dedicated enclosure structure. A pair of distributor valves is mechanically coupled to both the primary cooling circuit and the emergency cooling unit. The valves are configured to selectively disconnect the cold plate assembly from the primary cooling circuit and connect the cold plate assembly with the emergency cooling unit when prompted by a control signal, thereby providing an emergency cooling function for a predefined period of time.

Description

Technical Field

[0001] Various examples of the present disclosure generally relate to the field of liquid-cooled hardware systems. Various examples of the present disclosure specifically relate to emergency cooling systems for liquid-cooled systems in automotive applications. Background Art

[0002] In various industries such as automotive, aerospace, and high-performance computing, hardware components often generate a lot of heat due to their operation. Specifically, high-power and high-heat-density electronic devices are traditionally cooled by liquid-cooled systems. These systems use cold plates to transfer heat, which is then dissipated by circulating cooling liquid through these plates. Nevertheless, there is still a risk of cooling liquid loss or cooling system failure during normal operation. During such situations, it becomes critical to maintain the operation of safety-critical features in emergency mode for a specific duration to avoid potential failures or accidents. However, the thermal capacity of cold plates and printed circuit boards (PCBs) is generally insufficient to support emergency operations for the required duration. For example, in the automotive field, functions such as digital cockpit operation, body control, and autonomous driving must remain functional for a predefined period of time. Summary of the invention

[0003] Therefore, there exists a need for advanced techniques for these emergency scenarios that alleviate or mitigate at least some of the above-identified limitations and shortcomings.

[0004] This need is met by the features of the independent claim. Features of the dependent claims define further advantageous examples.

[0005] In the following, the solution according to the present disclosure will be described with respect to a claimed cooling system and with respect to a claimed cooling method, wherein features, advantages or alternative embodiments may be assigned to other claimed objects and vice versa. In other words, the claims relating to the cooling system may be improved with features described in the context of the cooling method, and the cooling method may be improved with features described in the context of the cooling system. Furthermore, any cooling device and / or control unit and / or computer program and / or computer-readable storage medium may be improved with features described in the context of the system and the method.

[0006] A liquid-cooled system is disclosed, which is configured to provide emergency cooling to a heat source to be cooled. The liquid-cooled system includes a main cooling circuit or a conventional cooling circuit / system through which a cooling liquid (also commonly referred to as a coolant) circulates to dissipate heat. A cold plate or cold plate assembly that can be thermally connected to the heat source transfers heat from the heat source to the cooling liquid when the cooling liquid circulates through the cold plate. In various examples, the cooling liquid in the main cooling circuit can be dissipated to the surrounding environment or guided by the main cooling circuit to the outside of the liquid-cooled system, thereby effectively transferring heat from the heat source to the outside of the liquid-cooled system. The system also includes an emergency cooling unit, which includes a phase change material (PCM) contained in a housing structure, wherein the system is configured to use the emergency cooling unit to provide emergency cooling to the heat source. A pair of distributor valves are mechanically connected to the main cooling circuit and the emergency cooling unit. The valve can selectively disconnect the cold plate assembly from the main cooling circuit and connect the cold plate assembly to the emergency cooling unit in response to a control signal. The emergency cooling unit may be used in emergency situations when the main cooling circuit is not operational, wherein the cooling liquid is cooled using the emergency cooling unit, as will be described in more detail below.

[0007] In various examples, the primary cooling loop may also be referred to as a main or conventional cooling loop or system. In normal operation, a cooling liquid circulates in the primary cooling loop of a liquid-cooled system. The cooling liquid is pumped into a cold plate assembly that is thermally coupled to a heat source. Here, the cooling liquid absorbs heat generated by the heat source. After absorbing heat from the heat source, the heated cooling liquid flows away from the cold plate assembly and moves toward a heat exchanger in the primary cooling loop. The heat exchanger may be an air-cooled radiator, a water-cooled condenser, or another type of cooling device that dissipates heat from the cooling liquid to the surrounding environment or another cooling medium. Inside the heat exchanger, the cooling liquid releases the absorbed heat, thereby cooling down. The heat is transferred to the surrounding environment or a secondary cooling medium, such as air or water, that is subsequently discharged from the system to complete the heat exchange process. After the cooling liquid has been cooled in the heat exchanger, the cooling liquid is recirculated back to the cold plate assembly, where the cooling liquid can absorb heat from the heat source again. This continuous circulation of the cooling liquid through the primary cooling loop enables consistent and efficient heat transfer from the heat source in normal operation. This helps maintain the heat source (typically high-power electronic equipment) within a safe operating temperature range.

[0008] A cold plate assembly (also known as a heat sink or heat exchanger) facilitates the transfer of heat from a heat source to a cooling liquid. The cold plate assembly is thermally coupled to the heat source, meaning that the cold plate assembly is positioned in such a way that it can effectively absorb heat from the heat source. In direct contact, the cold plate assembly can be physically attached to the heat source, generally through a thermal interface material (TIM) that fills any air gaps and provides a high thermal conductivity path for heat transfer. The TIM can be a thermally conductive paste, thermally conductive pad, or thermally conductive glue applied between the cold plate assembly and the heat source. In indirect contact, the cold plate assembly can be connected to a heat sink that is directly attached to the heat source. The heat sink absorbs heat from the heat source and then transfers the heat to the cold plate assembly. This approach can be used when the surface of the heat source is not suitable for direct contact with the cold plate.

[0009] In various examples, heat sources may include high-power electronics in automotive applications or in vehicles. These may include, for example, electronics for digital cockpits, autonomous driving systems, and other electronic systems in vehicles that generate large amounts of heat. These systems need to be cooled to maintain their performance and reliability.

[0010] Distributor valves may also be referred to as switching valves or control valves. Distributor valves are mechanical devices included in the flow path of the cooling liquid. They are intended to control the direction of the cooling liquid flow between the main cooling circuit and the emergency cooling unit. Distributor valves may be located at various points within the pipes or tubing of the cooling system. They act as nodes at alternate flow paths. When in their default position, the distributor valves allow the cooling liquid to flow from the main cooling circuit to the cold plate assembly, enabling normal operation of the cooling system. When a control signal is received (such as when a fault in the main cooling circuit is detected), the distributor valves switch positions. They disconnect the flow path from the main cooling circuit and connect the cold plate assembly to the emergency cooling unit. This effectively redirects the cooling liquid to the emergency cooling unit, initiating emergency operation of the cooling system. The distributor valves may be positioned in such a way that the flow path immediately before the cold plate assembly (in direct thermal contact with the heat source) is shared between normal operation and emergency operation. This design enables a smooth transition between the main cooling circuit and the emergency cooling unit, ensuring that the heat source can be continuously cooled even in the event of a fault in the main cooling circuit. Therefore, whether it is from the main cooling circuit or the emergency cooling unit, the cooling liquid can continuously cool the heat source and maintain the performance and safety of the system.

[0011] This configuration of the distributor valve and its operation essentially forms an emergency cooling circuit that can be activated when the primary cooling circuit fails. The control signal can be triggered by a variety of conditions, including a failure or abnormal operation within the primary cooling circuit, or excessive heat generation from a heat source.

[0012] The emergency cooling circuit may include a pump for enabling the cooling liquid to circulate through the cold plate assembly and the emergency cooling unit during the emergency operating mode. This pump, when activated, ensures that the cooling liquid flows through the emergency cooling unit, enabling heat exchange between the cooling liquid and the PCM.

[0013] The emergency cooling unit includes a phase change material (PCM) that enables emergency cooling when the primary cooling circuit fails. The cooling effect in the emergency cooling unit is achieved by the PCM acting as a heat sink.

[0014] The PCM contained within the emergency cooling unit is a material that absorbs or releases thermal energy when its phase changes. Common examples of PCMs include paraffin waxes, salt hydrates, and certain types of polymers, but the precise type of PCM used will be selected based on factors such as its melting point and its heat storage capacity.

[0015] The function of the PCM in the emergency cooling unit is to absorb and store heat from the cooling liquid during an emergency situation. When the cooling liquid from the main cooling circuit is redirected to the emergency cooling unit, the cooling liquid comes into contact with the PCM. The PCM in a solid state absorbs heat from the cooling liquid and changes to a liquid state, a process called melting. This phase change occurs at a constant temperature, and the amount of heat absorbed (latent heat of fusion) is large, allowing the PCM to absorb and store a large amount of thermal energy.

[0016] The emergency cooling unit may also contain cooling fins or other heat exchange elements to increase its surface area, thereby enhancing heat transfer between the cooling liquid and the PCM. These elements may be designed in various shapes and sizes, and they may be arranged in various configurations to optimize heat transfer.

[0017] The emergency cooling unit may also be called a heat bank or buffer unit. It is intended to provide temporary emergency cooling in case of a failure in the main cooling circuit, where the heat is no longer transferred to the outside of the liquid cooling system, but is stored in the PCM, within the emergency cooling unit, through phase change.

[0018] The emergency cooling unit is a thermally independent module, which houses a phase change material (PCM). The phrase thermally independent refers to the fact that the emergency cooling unit is isolated from the main cooling circuit under normal operating conditions. It does not participate in the normal cooling process, but is only used to provide emergency cooling. Therefore, the normal cooling circuit and the emergency cooling circuit cannot be operated simultaneously, but are selectively switched.

[0019] The emergency cooling unit may be thermally isolated from its surroundings, except for the inflow and outflow of cooling liquid in the emergency operating mode.

[0020] The emergency cooling unit is formed by a housing structure filled with PCM. The housing structure may be a sealed and / or insulated box or container, which is intended to maintain the PCM in a stable state. It is intended to isolate the PCM from the surrounding environment and the main cooling circuit, preventing unnecessary heat transfer and ensuring that the thermal reservoir of the PCM is available for emergency situations.

[0021] The emergency cooling unit can be located close to or far from the heat source. It can be connected to the cold plate assembly via pipes or ducts, allowing cooling liquid to be transported to and from the emergency cooling unit.

[0022] The emergency cooling unit is designed to be thermally decoupled from the surrounding environment, heat sources and the main cooling circuit under normal operation. The decoupling ensures that the thermal energy stored in the phase change material (PCM) inside the emergency cooling unit is not exhausted prematurely and can be used in emergency situations.

[0023] Thermal decoupling is primarily achieved through the housing structure that houses the PCM. This structure can be designed and manufactured with materials that have low thermal conductivity, such as certain plastics or composite materials. In addition, the structure can also incorporate an insulating layer to further reduce heat exchange with the surrounding environment.

[0024] During normal operation, the distributor valve in the cooling system ensures that the cooling liquid flows only through the main cooling circuit and not into the emergency cooling unit. This maintains the thermal decoupling of the emergency cooling unit from the heat source and the main cooling circuit. Thus, the solid state of the PCM is preserved and the emergency cooling unit remains in standby mode.

[0025] However, when the system enters emergency operation (generally due to a failure or interruption of the main cooling circuit), the distributor valve switches position in response to a control signal. This redirects the cooling liquid from the main cooling circuit to the emergency cooling unit via a pump integrated in the emergency cooling circuit. The emergency cooling unit is thus thermally coupled to the heat source via the cooling liquid.

[0026] In this state, the cooling liquid absorbs heat from the heat source and transports the heat to the emergency cooling unit where it is absorbed by the PCM. The PCM undergoes a phase change, absorbs heat from the cooling liquid, and thereby cools down the cooling liquid, which is then recirculated back to the heat source. Thus, the emergency cooling unit can store excess heat entering the emergency cooling unit through the cooling liquid for a predefined period of time, the excess heat exceeding the predefined melting temperature of the PCM.

[0027] This mechanism ensures a continuous cooling effect during emergency operation in the event of a failure in the main cooling circuit. After the emergency operation, the emergency cooling unit can be recharged (ie the PCM can solidify again).

[0028] Thus, the ability of the cooling system to switch from the primary cooling circuit to the emergency cooling unit (ie, the emergency cooling unit) ensures continued cooling of the heat source even during failure of the primary cooling circuit, thereby enabling system uptime in the event of a primary cooling system failure.

[0029] The liquid-cooled system may also include a control unit. The control unit may be configured to monitor the main cooling circuit, and / or the emergency cooling unit, and / or the heat source. It may be configured to determine the operating state of the main cooling circuit based on the monitoring. It may generate a control signal to trigger the distributor valve based on the operating state of these monitored components and / or sensors. The control unit may also be referred to as a control module or a control system. It is responsible for managing the operation of the cooling system. It monitors the status of different components and generates a control signal based on the observed conditions, which activates the distributor valve and switches between the main cooling circuit and the emergency cooling circuit.

[0030] The control unit may be responsible for monitoring the various other elements within the system, interpreting the inputs, and generating control signals for the dispenser valves.The control unit may receive various inputs, as will be described in detail below.

[0031] One or more pressure sensors and temperature sensors may be located at various points in the system, including the heat source, the main cooling circuit, and the emergency cooling unit. These sensors may continuously monitor the temperature and pressure within the main cooling circuit and may send this data to the control unit. If a pressure drop occurs below a pressure threshold, or a temperature rise at the heat source or within the main cooling circuit exceeds a predefined threshold, this may indicate a fault in the main cooling circuit and trigger the control unit to start the emergency cooling unit. On the other hand, if the temperature within the emergency cooling unit reaches a predefined maximum value, the control device may use this value and data from the sensors in the main cooling circuit as input to signal the distributor valve to reconnect the cold plate assembly to the main cooling circuit, thereby indicating the end of the emergency cooling operation. In particular, a decrease in the pressure of the cooling liquid in the main cooling circuit below a pressure threshold may indicate an emergency situation in the main cooling system. In various examples, the control device may also receive information or sensor data about the emergency situation from a communication network within the vehicle.

[0032] For example, a cooling liquid flow rate sensor may be placed in the main cooling circuit to monitor the rate of cooling liquid flow. If the cooling liquid flow rate falls below a certain level, this may indicate a blockage or leak in the main cooling circuit, and the control unit may generate a control signal to initiate an emergency cooling operation.

[0033] The control unit may also receive input from other types of sensors, such as a pressure sensor to monitor the cooling liquid pressure or a humidity sensor to detect cooling liquid leaks.

[0034] The control unit may be linked to a user interface from which the control unit may receive manual input from a user or operator. This may be used, for example, to manually initiate an emergency cooling operation or to adjust a threshold value that determines when the control unit generates a control signal.

[0035] Using these inputs, the control unit is configured to determine the operating state of the cooling system.If the control unit detects an abnormal condition in the primary cooling circuit (such as a pressure drop, increased temperature, reduced flow rate or reduced pressure), the control unit generates a control signal to activate the distributor valve.

[0036] Thus, the control signal triggers the distributor valve to switch from its normal position (in which the distributor valve couples the cold plate assembly with the main cooling circuit) to its emergency position (in which the distributor valve couples the cold plate assembly with the emergency cooling unit). This change in valve position redirects the flow of cooling liquid from the main cooling circuit to the emergency cooling unit, thereby initiating an emergency cooling operation.

[0037] Therefore, a control unit is added, which makes the system more intelligent. The control unit ensures that the system can respond appropriately to changes in operating conditions, thereby improving the reliability and effectiveness of the cooling system.

[0038] The liquid-cooled system may further be configured to operate in different operating modes. A normal operating mode involves cooling the liquid through the main cooling circuit while the distributor valve connects the cold plate assembly to the main cooling circuit and prevents the cooling liquid from entering the emergency cooling unit. An emergency operating mode involves the distributor valve disconnecting the cold plate assembly from the main cooling circuit in response to a control signal and connecting the cold plate assembly to the emergency cooling unit, so that the cooling liquid can be cooled by the emergency cooling unit by using a small pump in the emergency circuit.

[0039] Therefore, these two operation modes may also be referred to as normal operation mode and emergency operation mode.The distributor valve may selectively connect the cold plate assembly with the main cooling circuit or the emergency cooling unit based on cooling requirements.

[0040] In addition to the normal and emergency modes already described, the liquid-cooled system can potentially include several additional modes of operation. These can enhance the versatility, efficiency, and life of the system.

[0041] Another mode of operation is to fill the system with cooling liquid for the first time or to fill the system with cooling liquid after a loss of cooling liquid event.

[0042] For example, after an emergency cooling operation, the phase change material (PCM) in the emergency cooling unit will be in its liquid phase, having absorbed heat from the cooling liquid. In the recovery mode, the system will start working to solidify the PCM again, thereby restoring its ability to absorb heat in future emergency situations. The recovery of the emergency unit may be performed passively, without the need for a specific process. The recovery may be achieved by at least connecting the emergency cooling unit to the cooling circuit of the vehicle. The control unit may monitor the temperature of the PCM and switch to the recovery mode when the control unit detects that the PCM is in its liquid phase and the conditions are suitable for recovery.

[0043] Predictive modes can leverage advanced analytics and machine learning techniques. The control unit can be equipped with a trained model that uses historical and real-time sensor data to predict potential failures in the primary cooling circuit based on continuous monitoring of various sensors. If the model predicts a failure with a high degree of confidence, the system can initiate emergency cooling operations, ensuring uninterrupted cooling of the heat source. This approach can help avoid damage to the heat source and maintain system performance without increasing the temperature of the heat source.

[0044] Under certain conditions, it may be beneficial to cool the PCM in the emergency cooling unit, particularly if the ambient temperature is high. In this mode, the control unit may use sensor data (e.g., ambient temperature, PCM temperature) to decide when to initiate PCM cooling mode. This may involve connecting the emergency cooling unit to a low temperature circuit in the vehicle or using a thermoelectric cooling module to reduce the temperature of the PCM. Reducing the temperature of the PCM may increase its ability to absorb heat during the next emergency cooling operation.

[0045] In some cases, it may be beneficial to use both the main cooling circuit and the emergency cooling unit to cool the heat source. In this mixed mode, the distributor valve can be controlled in a way that allows part of the cooling liquid to flow to the emergency cooling unit. This may be advantageous, for example, when a heat source is expected to generate a higher heat load than usual.

[0046] Including these additional modes increases the robustness of the cooling system and optimizes its performance under different operating conditions, contributing to the overall reliability and safety of the system.

[0047] The phase change material (PCM) in the emergency cooling unit may have a melting point within a predefined temperature range that allows the phase change material to absorb heat from the cooling liquid while maintaining the cooling liquid between predefined cooling liquid temperature limits. The phase change material may be a substance having a melting point within a specific range that is suitable for absorbing heat from the cooling liquid. This substance changes from a solid to a liquid (or vice versa) within a defined temperature range. Thus, the PCM may absorb heat at a nearly constant temperature. This feature enables the cooling system to maintain the temperature of the heat source within a predefined range during emergency operation, thereby ensuring safe and reliable operation of the heat source.

[0048] The control unit may be configured to detect a fault in the primary cooling circuit and generate a control signal in response to the detected fault. Fault detection by the control unit may involve monitoring parameters such as cooling liquid temperature, cooling liquid flow rate, and pressure within the primary cooling circuit. An abnormality in these parameters may indicate a fault in the primary cooling circuit. Thus, the control unit may detect a fault in the primary cooling circuit and respond appropriately. This feature enhances the reliability of the cooling system and ensures safe operation of the heat source during a fault in the primary cooling circuit.

[0049] Heat sources may include high power and / or high heat density electronics in automotive applications. High power electronics may include components such as processors, power supplies, motor controllers, and components that generate a lot of heat during operation. This enhances the reliability and safety of these electronic systems that are critical to the operation and performance of modern vehicles.

[0050] The emergency cooling unit may be thermally isolated from the surrounding environment and the main cooling circuit by a housing structure. The housing structure may be designed to minimize thermal interactions between the PCM and the surrounding environment. The housing structure may be constructed of a material with high thermal resistance. Thus, the PCM may be maintained in a ready state by reducing heat absorption from the environment. This feature ensures that the PCM can provide effective cooling when the system is switched to emergency mode.

[0051] The control unit may receive and / or use input from at least one pressure sensor, and / or temperature sensor and / or at least one cooling liquid flow rate sensor in the primary cooling circuit to determine the operating state of the primary cooling circuit, in particular emergency situations. The pressure sensor, temperature sensor and cooling liquid flow rate sensor may provide real-time data on the operation of the primary cooling circuit. These sensors may help detect anomalies, such as overheating and insufficient cooling liquid flow.

[0052] The control unit may be configured to monitor the temperature of the heat source based on data received from the temperature sensor. The temperature sensor may provide real-time data regarding the temperature of the heat source. The temperature sensor may help the control unit monitor the effectiveness of the cooling system and detect potential overheating conditions. This ensures that the heat source operates within a safe temperature range, thereby enhancing the reliability and safety of the system.

[0053] The control unit may further be configured to receive data from a temperature sensor or a pressure sensor within the emergency cooling unit and generate a control signal based on the data from the temperature sensor within the emergency cooling unit. The temperature sensor within the emergency cooling unit may provide data about the PCM in the emergency cooling unit. This sensor may help the control unit decide when to switch to emergency mode and for how long to switch to emergency mode. This ensures that the system switches to emergency mode when the PCM can provide effective cooling, thereby enhancing the reliability and safety of the system.

[0054] The control unit may be configured to communicate with a user interface to provide alerts and updates to the user regarding the status of the cooling system. The user interface may provide visual and / or audible alerts and updates regarding the operating conditions of the cooling system. The user interface may help the operator or driver to respond quickly to emergency situations. This enhances the user's ability to respond to emergency situations, thereby improving the safety and reliability of the system.

[0055] The distributor valve may be configured to automatically reconnect the cold plate assembly to the main cooling circuit when the emergency cooling unit reaches a predefined temperature. The distributor valve may be set to reengage the cold plate assembly to the main cooling circuit upon detecting that the PCM in the emergency cooling unit has reached a temperature indicating exhaustion or reduced efficiency thereof.

[0056] Therefore, once the cooling capacity of the emergency cooling unit decreases, the cooling system can automatically switch back to the main cooling circuit. This feature ensures optimal utilization of cooling resources and further enhances system reliability.

[0057] The distributor valve may be designed to provide a liquid and airtight seal when in the closed position to prevent leakage of cooling liquid and maintain thermal isolation of the emergency cooling unit. The distributor valve may also be described as being able to form a hermetic seal. The distributor valve is designed to prevent any cooling liquid from leaking into the cooling system or mixing between the primary and secondary cooling systems. Thus, the valve prevents leakage of cooling liquid, thereby ensuring that the cooling systems remain closed and isolated. This feature is critical to maintaining system pressure and preventing mixing of different cooling liquids, thereby contributing to the overall reliability and safety of the system.

[0058] The size of the emergency cooling unit may be determined based on the cooling capacity of the system during a predefined emergency operation period. The emergency cooling unit may be designed with a PCM of a specific size or volume to meet the cooling needs during the predefined emergency operation period. This sizing may be based on factors such as the heat generation rate of the heat source and / or the cooling capacity of the PCM and / or the expected emergency operation time. The thermal capacity of the emergency cooling unit may be sized so that the cooling liquid can be maintained within the normal operating temperature range for at least 5 minutes, or at least 10 minutes, or at least 20 minutes. This ensures that the heat source can operate safely during this period, thereby enhancing the reliability and safety of the system.

[0059] A corresponding method for emergency cooling in a liquid-cooled system is provided, the corresponding method comprising monitoring a main cooling circuit by a control unit, generating a control signal based on a state of the main cooling circuit, disconnecting a cold plate assembly from the main cooling circuit in response to the control signal and connecting the cold plate assembly to an emergency cooling unit containing a phase change material within a housing structure, and cooling a cooling liquid using a PCM in the emergency cooling unit.

[0060] This method may be performed, for example, by any cooling system as described throughout this disclosure, and enables a liquid-cooled system to operate in emergency situations where the primary cooling circuit fails or is insufficient to meet cooling needs.

[0061] A control unit may be configured to implement a method according to the present disclosure, wherein the computing device comprises a memory, an interface and at least one processing unit, the memory containing instructions executable by the at least one processing unit, wherein execution of the instructions causes the computing device to perform any method or combination of methods according to the present disclosure.

[0062] A computer program or a computer program product may include program code to be executed by at least one processor of a computing device, wherein the execution of the program code causes the at least one processor to perform one of the methods according to the present disclosure.

[0063] A computer-readable storage medium may include instructions that, when executed by a processor, cause the processor to implement any method or combination of methods according to the present disclosure.

[0064] With such a control unit, a method for operating a cooling system, a computer program and a computer-readable storage medium for operating a liquid-cooled system, technical effects corresponding to those described for the cooling system can be achieved.

[0065] It should be understood that the features mentioned above and those yet to be explained below may be used not only in the indicated corresponding combinations, but also in other combinations or independently, without departing from the scope of the present disclosure. Specifically, the features mentioned above and those yet to be explained below may be used not only in the indicated corresponding combinations, but also in other combinations or independently, without departing from the scope of the present disclosure.

[0066] Therefore, the above summary is intended only to give a brief overview of some features of some embodiments and implementations, and should not be construed as limiting.Other embodiments may include other features besides those explained above. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] These and other objects of the present invention will be appreciated and understood by those skilled in the art from the detailed description of the preferred embodiments and the following drawings, in which like reference numerals refer to like elements.

[0068] Figure 1 Schematically depicted is an overview of a liquid cooled system according to various embodiments.

[0069] Figure 2 Schematically illustrates various embodiments of Figure 1 The cooling liquid flow path of a liquid-cooled system during normal operation.

[0070] Figure 3 Schematically illustrates various embodiments of Figure 1 The cooling liquid flow path of a liquid-cooled system during emergency operation.

[0071] Figure 4 It is shown that according to various embodiments, Figure 1 The steps of a method for emergency cooling implemented by a liquid cooling system. DETAILED DESCRIPTION

[0072] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be understood that the following description of the embodiments should not be understood in a limiting sense. The scope of the present invention is not intended to be limited by the embodiments described below or by the accompanying drawings, which are considered as illustrative examples of general inventive concepts. The features of the various embodiments may be combined with each other unless otherwise specifically noted.

[0073] The drawings should be considered as schematic representations, and the elements shown in the drawings are not necessarily shown to scale. Instead, the various elements are represented so that their functions and general purposes are apparent to those skilled in the art. Any connection or coupling between the functional blocks, devices, components or other physical or functional units shown in the drawings or described herein may also be achieved by indirect connection or coupling. Coupling between components may also be established via wired connections. Functional blocks may be implemented in hardware, firmware, software or a combination thereof.

[0074] Below, a technology related to a cooling system using a cooling liquid will be described. The liquid-cooled system can be a liquid-cooled automotive system, or a liquid-cooled system in or on a vehicle. In various examples, the described technology is also referred to as a liquid cooling method or an emergency cooling method or system, respectively.

[0075] Generally speaking, techniques are described for forming an emergency cooling loop for a liquid-cooled system, particularly a liquid-cooled system in a vehicle. When a primary cooling system or subsystem fails or ceases to function, the emergency cooling system or subsystem is activated and maintained in operation for a defined period of time to allow mitigation and intervention measures to be taken, while the conventional cooling loop remains inoperative or has reduced operability.

[0076] The system described utilizes a phase change material (PCM) to absorb heat at a constant temperature and cool the cooling liquid. When the primary cooling system fails, a distributor valve disconnects the cold plate from the vehicle's cooling circuit and connects the cold plate to an emergency cooling system filled with PCM. This ensures that critical systems such as the digital cockpit, body control, and autonomous driving can still function for a certain amount of time in an emergency situation, thereby preventing accidents.

[0077] Figure 1 A liquid-cooled system 1 according to various embodiments is schematically illustrated.

[0078] like Figure 1 As can be seen in the figure, the liquid-cooled system 1 includes a main cooling circuit (as indicated by the arrows) connected to the vehicle cooling circuit, which circulates cooling liquid from the vehicle cooling circuit through a cold plate 3 to dissipate heat from two heat sources 2 (in this case, high-power electronic devices in automotive applications), as shown by the arrows pointing to the liquid-cooled system. The cooling liquid that stores heat from the heat sources is circulated back to the vehicle cooling circuit, as indicated by the arrows pointing out of the liquid-cooled system 1. The liquid-cooled system 1 also includes a cold plate 3 (also called a cold plate assembly) that is thermally connected to the heat source 2, and the cold plate is intended to dissipate heat from the heat source 2 and transfer heat to the circulating cooling liquid, which should be understood as a conventional circuit or conventional cooling circuit operated in a normal operating mode. In normal operation, the heat can be dissipated to the surrounding environment, for example, by a secondary cooling circuit or a fan or similar known technology.

[0079] Figures 1 to 3 The liquid-cooled system 1 further comprises a control unit 8, which is configured to control the distributor valve 6 and the pump 7 in the liquid-cooled system 1 according to any method or combination of methods as described in the present disclosure. In particular, the control unit 8 is capable of receiving data from the vehicle communication system, various sensors located at the main cooling circuit, the heat source and / or the emergency cooling unit, determining the operating state of the main cooling circuit based on this data, and switching between different cooling operating modes (e.g., a normal operating mode using the main cooling circuit and the vehicle cooling circuit, and an emergency operating mode using the emergency cooling circuit in the liquid-cooled system).

[0080] The liquid cooling system 1 comprises an emergency cooling circuit, which comprises an emergency cooling unit 5 and a pump 7 as well as a pipeline connecting the emergency cooling unit 5 with the cold plate 3. Figure 2 and Figure 3 Describing the piping in detail, these figures provide Figure 1 Further details of the liquid cooling system 1.

[0081] The emergency cooling circuit includes an emergency cooling unit 5, which contains a phase change material (PCM) in a housing or shell structure. This housing thermally isolates the emergency cooling unit 5 from the surrounding environment and the main cooling circuit. Within the emergency cooling unit 5, thermal fins 4 of high thermal conductivity material are formed, which help to effectively transfer heat from the cooling liquid to the PCM. The system 1 also includes a pair of distributor valves 6, which are mechanically connected to both the main cooling circuit and the emergency cooling unit 5. These valves 6 are able to selectively disconnect the cold plate 3 from the main cooling circuit and connect the cold plate to the emergency cooling unit 5 based on the monitored status of the main cooling circuit, the emergency cooling unit 5 and the heat source 2 under the control of a control unit (not shown). Thus, an emergency cooling circuit is formed. A pump 7 is included in the emergency cooling circuit so that the cooling liquid is circulated in the emergency cooling circuit once the distributor valve 6 connects the emergency cooling unit 5 to the cold plate 3.

[0082] Figure 2 Schematically illustrates various embodiments of Figure 1 Flow path of cooling liquid of the liquid-cooled system 1 during normal operation.

[0083] During this normal mode or normal operating mode, the cooling liquid is cooled in the main cooling circuit which is connected to the vehicle cooling circuit. The cooling liquid from the vehicle cooling circuit circulates through the cold plate and flows back into the vehicle cooling circuit, as indicated by the arrows. The distributor valve 6 set in its normal operating position ensures the connection between the cold plate 3 and the main cooling circuit, preventing the cooling liquid from entering the emergency cooling unit 5. The pump 7 is not operated. Therefore, the cooling liquid circulates through the cold plate 3 and transfers heat away from the heat source 2.

[0084] Figure 3 Schematically illustrates various embodiments of Figure 1 A cooling liquid flow path of a liquid-cooled system 1 during emergency operation.

[0085] When the main cooling circuit fails, for example when the temperature of the heat source 2 is above a threshold temperature or the temperature of the cooling liquid is above such a limit, the distributor valve 6 disconnects the cold plate 3 from the main cooling circuit and connects the cold plate to the emergency cooling unit 5, wherein the pump 7 is activated to circulate the cooling liquid through the cold plate 3. As indicated by the arrows, in this emergency operating mode, an emergency cooling circuit is formed within the liquid-cooled system 1. The cooling liquid circulates only through the emergency cooling unit 5 and is cooled by storing heat within the emergency cooling unit 5, wherein the PCM absorbs heat from the cooling liquid, melts, and thus maintains a constant temperature to cool the liquid as long as a phase change can be performed. In various examples, by switching to the emergency cooling circuit, the operation of critical components (which may be high-power or safety-related electronic equipment) can be ensured for more than 10 minutes without the main cooling circuit operating.

[0086] Figure 4 It is shown that according to various embodiments, Figure 1 The steps of the method for emergency cooling are implemented in a liquid cooling system 1 .

[0087] The method starts at step S10. In step S20, the operating state of the main cooling circuit is monitored by the control unit. This monitoring process may involve checking data from temperature sensors and cooling liquid flow rate sensors, and possibly checking other operating parameters of the main cooling circuit. In step S30, a control signal is generated based on the operating state determined in the previous step. This control signal may be generated due to a variety of triggering factors, such as detecting a fault in the main cooling circuit or observing an abnormal (i.e., not within a predefined limit or threshold) temperature. In step S40, upon receiving the control signal, the cold plate assembly is disconnected from the main cooling circuit by switching the distributor valve. At the same time, the cold plate assembly is connected to an emergency cooling unit. This emergency cooling unit contains a phase change material (PCM) within a housing structure, providing an alternative cooling mechanism isolated from the main cooling circuit. In step S50, the cooling liquid is cooled using the PCM in the emergency cooling unit. The PCM absorbs heat from the cooling liquid and thus performs a phase change, for example, from solid to liquid, so as to maintain a constant temperature to cool the liquid. The method ends at step S60.

[0088] In summary, a liquid-cooled system is intended for use with high heat density electronics in automotive applications. This system includes a primary cooling loop and a cold plate assembly thermally coupled to a heat source, which in this context is the high heat density electronics. A cooling liquid is circulated through this primary cooling loop to dissipate heat generated by the heat source.

[0089] An important feature of the present technology is the inclusion of an emergency cooling circuit or loop, which includes an emergency cooling unit containing a phase change material (PCM). This PCM is designed to absorb heat at a constant temperature, thereby cooling the cooling liquid. This feature can prove particularly beneficial when the main cooling system fails or stops working, and can operate independently of other cooling systems or the surrounding environment.

[0090] The PCM can be selected based on its specific melting point, which ideally should be within the operating temperature range of the cooling liquid. When the cooling liquid (heated by the electronic device or heat source it is to cool) comes into contact with the PCM, the latter absorbs the excess heat and undergoes a phase change - from solid to liquid. This phase change is characterized by the PCM being able to absorb a large amount of energy while keeping its temperature constant, i.e. at its melting point.

[0091] Thus, if the temperature of the cooling liquid is above the melting point of the PCM, the cooling liquid transfers its excess heat to the PCM until the cooling liquid cools to the melting point of the PCM. The PCM will begin to melt as it absorbs this heat, but its temperature will remain constant, i.e., at its melting point, until it has completely melted. This allows the PCM to absorb large amounts of heat without a corresponding increase in temperature, and this property can be used to keep the cooling liquid within a relatively stable predefined temperature range even under high heat load conditions.

[0092] Thus, the use of PCM helps provide an effective cooling buffer during emergency situations, allowing the electronic equipment to continue to operate safely for a long period of time even when the main cooling circuit fails or is disconnected.

[0093] The system also includes a pair of distributor valves mechanically coupled to both the primary cooling circuit and the emergency cooling unit. These valves are capable of disconnecting the cold plate assembly from the primary cooling circuit and connecting the cold plate assembly to the emergency cooling unit in response to a control signal. This action is particularly important in an emergency situation when the primary cooling system may fail, potentially compromising critical systems such as digital cockpit, body control, and autonomous driving.

[0094] The ability to switch seamlessly between these two modes ensures that emergency operation of the system can be maintained for a limited period of time. During this time, the driver can take over, or the vehicle can be safely moved to a safe area. This feature greatly enhances the safety and reliability of the liquid-cooled system and the vehicle in which it is installed, especially during emergency situations.

[0095] In summary, this liquid-cooled system integrates a secondary fail-safe cooling system for high-power, high-heat-density electronics in the vehicle, significantly improving operational safety and reliability in potential emergency situations.

[0096] It should be understood that the described techniques have been described for cooling systems in vehicles, but it is clear that these techniques can be used with any system including liquid-cooled systems. Similar techniques can be readily applied to other kinds and types of cooling systems, such as, for example, buildings, computing hardware, or electronic consumer devices.

[0097] Although the disclosed technology has been described with respect to certain preferred embodiments, equivalents and modifications will occur to others skilled in the art upon reading and understanding this specification. The present disclosure includes all such equivalents and modifications and is limited only by the scope of the appended claims.

Claims

1. A liquid cooling system, comprising: - a primary cooling circuit through which a cooling liquid circulates to remove heat; - a cold plate assembly capable of being thermally coupled to a heat source to transfer heat from the heat source to the cooling liquid; - an emergency cooling unit comprising a phase change material (PCM) housed within a housing structure; - a pair of distributor valves mechanically coupled to the main cooling circuit and the emergency cooling unit, configured to selectively disconnect the cold plate assembly from the main cooling circuit and connect the cold plate assembly to the emergency cooling unit in response to a control signal.

2. The liquid cooling system according to claim 1, further comprising a control unit, wherein the control unit is configured to: - monitoring at least one of the main cooling circuit, the emergency cooling unit and the heat source based on sensor data from sensors arranged at the respective elements; - identifying an emergency situation based on one or more of: a pressure of the cooling liquid in the primary cooling circuit dropping below a pressure threshold, a flow rate of the cooling liquid in the primary cooling circuit dropping below a flow rate threshold, and a temperature of the cooling liquid in the primary cooling circuit increasing above a temperature threshold; and - generating said control signal for enabling emergency operation based on the identified emergency situation.

3. The liquid-cooled system according to claim 1 or 2, wherein the liquid-cooled system is further configured to operate in the following modes: a normal operating mode, wherein the cooling liquid is cooled by the main cooling circuit and wherein the distributor valve connects the cold plate assembly with the main cooling circuit, and wherein the distributor valve prevents cooling liquid from entering the emergency cooling unit; and - an emergency operating mode, wherein the distributor valve disconnects the cold plate assembly from the main cooling circuit and connects the cold plate assembly to the emergency cooling unit in response to the control signal, thereby allowing the cooling liquid to be cooled by the emergency cooling unit.

4. The liquid-cooled system according to claim 3, wherein the control unit is further configured to enable the emergency operation mode for a predetermined amount of time, in particular more than 10 minutes. 5 . The liquid cooled system of claim 4 , wherein the control unit is further configured to determine the predetermined amount of time based on a thermal capacity of the cold plate assembly and / or a thermal power loss of the heat source.

6. The liquid-cooled system according to one of the preceding claims, wherein the liquid-cooled system is an on-board liquid-cooled system, wherein the heat source comprises electronic circuits of an automotive computing device.

7. The liquid-cooled system according to one of claims 2 to 6, wherein the control unit is further configured to gradually transition between the main cooling circuit and the emergency cooling unit based on one or more of the following: a rate of change of the pressure of the cooling liquid in the main cooling circuit and a reduction in the cooling liquid flow rate of the main cooling circuit.

8. Liquid-cooled system according to one of the preceding claims, wherein the emergency cooling unit forms a local emergency cooling circuit with the cold plate assembly, wherein thermal energy is stored in the emergency cooling unit and is not transferred to the main cooling circuit.

9. The liquid-cooled system according to one of claims 2 to 8, wherein the control unit is configured to monitor the pressure within the primary cooling circuit based on data received from a pressure sensor and to generate the control signal based on the data from the pressure sensor.

10. The liquid-cooled system according to one of the preceding claims, wherein the control unit is further configured to receive data from a temperature sensor within the emergency cooling unit and to generate the control signal based on the data from the temperature sensor within the emergency cooling unit.

11. The liquid cooled system according to one of claims 2 to 10, wherein the control unit is configured to communicate with a user interface to provide an alert regarding an emergency situation of the cooling system or to receive user input regarding an emergency situation of the primary cooling circuit.

12. Liquid-cooled system according to one of the preceding claims, wherein the emergency cooling unit comprises a heat exchanger forming a plurality of cooling fins thermally coupled to the PCM.

13. The liquid-cooled system according to one of the preceding claims, wherein the emergency cooling unit is sized based on the cooling capacity of the system during a predefined emergency operation period, wherein the main cooling circuit is not connected to the cold plate assembly.

14. A method for emergency cooling of a liquid-cooled system, the method comprising: - monitoring the main cooling circuit to identify emergency situations of said main cooling circuit; - generating a control signal based on the identified emergency situation; - transitioning the system to an emergency operating mode by disconnecting a cold plate assembly thermally coupled to a heat source from the primary cooling circuit and connecting the cold plate assembly to an emergency cooling unit comprising a phase change material housed within a housing structure in response to the control signal; and - During emergency operation, cooling the cooling liquid by the PCM in the emergency cooling unit for a predefined period of time.

15. The method for emergency cooling of a liquid cooled system of claim 14, wherein the predetermined amount of time is determined based on a thermal capacity of the cold plate assembly and / or a thermal power loss of the heat source.

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