A liquid cooling system for an energy storage converter and its monitoring method

Abstract

This invention discloses a liquid cooling system for an energy storage converter and its monitoring method, comprising the following steps: S1, acquiring monitoring data from a liquid immersion sensor, a temperature and pressure sensor, and a flow sensor; S2, determining whether the system is abnormal based on the monitoring data; if so, reducing the output power of the PCS to a safe power, issuing an alarm message to the host computer, and proceeding to S3; otherwise, proceeding to S1; S3, if the abnormality persists within a certain period of time, controlling the PCS and water chiller to shut down, and inspecting and repairing the liquid cooling system. The beneficial effects of this invention are: it can promptly and accurately detect liquid leakage in the liquid cooling system from the dimensions of liquid accumulation, pressure and flow rate changes, and vibration characteristics, improving the accuracy and reliability of leakage monitoring.

Description

Technical Field

[0001] This invention relates to the field of liquid cooling technology for energy storage converters, and more specifically to a liquid cooling system for an energy storage converter and its monitoring method. Background Technology

[0002] With the rapid development of energy storage technology, the performance and reliability of the power converter (PCS) are crucial components in energy storage systems. Liquid cooling systems are widely used in PCS to achieve efficient heat dissipation, but these systems are prone to leakage. Leakage can lead to short circuits in the PCS's internal circuitry, equipment damage, and even safety accidents.

[0003] In the existing technology, liquid cooling systems have shortcomings in leakage detection and protection, and cannot detect leakage in a timely and accurate manner, which affects the safe and stable operation of the PCS. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this application proposes a liquid cooling system for an energy storage converter and its monitoring method, which can promptly and accurately detect leakage phenomena in the liquid cooling system from the dimensions of liquid accumulation, pressure and flow rate changes, and vibration characteristics, thereby improving the accuracy and reliability of leakage monitoring.

[0005] The following is the technical solution of the present invention: a monitoring method for a liquid cooling system of an energy storage converter, comprising the following steps: S1. Acquire monitoring data from the liquid immersion sensor, temperature and pressure sensor, and flow sensor; S2. Based on the monitoring data, determine whether the system is abnormal. If so, reduce the output power of the PCS to a safe power, send an alarm message to the host computer, and proceed to S3. Otherwise, proceed to S1. S3. If the abnormality persists for a certain period of time, shut down the PCS and water chiller, and inspect and repair the liquid cooling system.

[0006] In a preferred embodiment of the present invention, in S2, if the control unit receives a signal from the liquid immersion sensor, the system is abnormal.

[0007] In a preferred embodiment of the present invention, in S2, the system pressure difference and flow rate satisfy a quadratic polynomial relationship, as expressed below: △P=aQ 2 +bQ+c In the above formula, ΔP is the system pressure difference, Q is the flow rate, and a, b, and c are coefficients obtained by fitting experimental and actual operating data; the relationship between the temperature correction coefficient and the coolant temperature is expressed as follows: k T =k T0 +α(T-T0) In the above formula, k T This is a temperature correction factor. Here, α is the temperature correction factor at the reference temperature T0, and α is the rate of change of the temperature correction factor. The system pressure difference is corrected to ΔP′=k T If △P′ is lower than the normal range [△P], min ,△P max If ], then the system is abnormal.

[0008] In a preferred embodiment of the present invention, the expression for calculating the rate of change of flow rate in S2 is as follows: In the above formula, δ is the rate of change of flow rate, and Q n Q represents the flow rate at the current moment. n-1 The flow rate value at the previous moment; The system is abnormal when the absolute value of the flow rate change δ is greater than the set threshold δ0.

[0009] As a preferred embodiment of the present invention, vibration sensor monitoring data is acquired, and a fast Fourier transform is performed on the vibration signal collected by the vibration sensor to obtain the spectrum of the vibration signal. The amplitude distribution of different frequency components in the spectrum is analyzed. If in a certain frequency range [f min ,f max Within [A], the vibration amplitude A changes beyond the set threshold ΔA or the vibration amplitude A exceeds the normal range [A]. min A max If ], then the system is abnormal.

[0010] A liquid cooling system for an energy storage converter, comprising: Liquid cooling plate, used to dissipate heat from the power devices inside the PCS; Piping is used to form coolant circulation channels and connect to liquid cooling plates; The air-water heat exchanger is used to transfer the heat of the high-temperature air inside the PCS to the coolant, thereby cooling the air and dissipating heat from the power devices inside the PCS. It is connected to the piping. A drip tray is used to collect coolant leaking from the pipes and is located directly below the quick-connect fittings where the pipes, liquid cooling plates, and air-water heat exchangers connect. A liquid immersion sensor is used to monitor the amount of water in the water receiving tray and is installed inside the water receiving tray; Temperature and pressure sensors are used to monitor the temperature and pressure of water entering and leaving the pipeline, and are installed at the inlet and outlet pipes of the pipeline. A flow sensor is used to monitor the flow rate of water entering and leaving a pipeline. It is installed at the inlet and outlet pipes of the pipeline. Vibration sensors are used to monitor vibration data and are installed at the inlet pipe, outlet pipe, and bends of the pipeline.

[0011] As a preferred embodiment of the present invention, the water receiving tray is a rectangular structure made of metal, welded to the shell, located directly below the quick-connect fitting, and its edges are sealed.

[0012] As a preferred embodiment of the present invention, a drainage hole is provided at the bottom of the housing, and a seal is formed by a combination of a cover plate and a sealing ring.

[0013] As a preferred embodiment of the present invention, it further includes: a vibration sensor for monitoring vibration data, which is installed at the inlet pipe, outlet pipe and elbow of the pipeline.

[0014] The beneficial effects of this invention are: 1. In this invention, by setting up components such as a water receiving tray, liquid immersion sensor, temperature and pressure sensor, vibration sensor, and flow sensor, a more comprehensive and refined multi-level leakage monitoring system is formed. It can detect leakage phenomena in the liquid cooling system in a timely and accurate manner from multiple dimensions such as liquid accumulation, pressure and flow changes, and vibration characteristics, including liquid leakage that has already occurred and potential leakage risks, which greatly improves the accuracy and reliability of leakage monitoring. 2. In this invention, the leakage monitoring method based on the relationship between system pressure difference and flow rate, combined with the comprehensive analysis of multiple parameters such as flow rate change rate, vibration spectrum analysis and temperature correction coefficient, can detect problems in the early stage of leakage through richer parameter changes and more accurately determine the location of leakage, thus gaining more time for equipment maintenance and reducing the degree of equipment damage. 3. In this invention, the protection strategy of reducing the PCS output power to a safe level when an abnormal situation is detected can reduce system pressure and coolant demand without immediate shutdown. This provides a buffer time to determine whether a complete shutdown is necessary, avoiding unnecessary downtime from impacting production. It also helps prevent further deterioration of leaks, improving system stability and reliability. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the liquid cooling system of the energy storage converter of the present invention; Figure 2 This is a schematic diagram of the liquid cooling system structure of the energy storage converter of the present invention; Figure 3 This is a flowchart of the monitoring method for the liquid cooling system of the energy storage converter of the present invention; In the diagram: 1. Housing; 2. Water tray; 3. Liquid cooling plate; 4. Power device; 5. Piping; 6. Air-water heat exchanger; 7. Drain hole; 8. Temperature and pressure sensor; 9. Vibration sensor; 10. Flow sensor; 11. Liquid immersion sensor. Detailed Implementation

[0016] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1 like Figure 1 and Figure 2 As shown, an energy storage converter liquid cooling system includes: a liquid cooling plate 3, a pipeline 5, a water-air heat exchanger 6, a water receiving pan 2, a liquid immersion sensor 11, a temperature and pressure sensor 8, a vibration sensor 9, a flow sensor 10, and a control unit.

[0018] The liquid cooling plate 3 is used to dissipate heat from the power devices 4 inside the PCS. The pipe 5 connects the liquid cooling plate 3, the air-water heat exchanger 6 and other components to form a coolant circulation channel. The water collection tray 2 is located directly below the quick-connect fittings that connect the pipe 5 to the liquid cooling plate 3, the air-water heat exchanger 6, and other components, and is connected to the housing 1. It is used to collect liquid leaking from the pipe fittings. The air-water heat exchanger 6 is used to transfer the heat of the high-temperature air inside the PCS to the coolant, thereby cooling the air and dissipating heat from the power devices inside the PCS. The water receiving tray 2 adopts a sealed structure design. A liquid immersion sensor 11 is arranged inside the water receiving tray 2. When there is a certain amount of water inside the water receiving tray 2, the liquid immersion sensor 11 can report a signal to the control unit. A drain hole 7 is provided on the housing 1. The drain hole 7 is located at the bottom of the equipment and is sealed by a combination of a cover plate and a sealing ring to ensure that the IP rating of the whole machine is not reduced. A temperature and pressure sensor 8 and a flow sensor 10 are installed at the water inlet pipe to collect the temperature, pressure and flow rate of the inlet water, respectively. A temperature and pressure sensor 8 and a flow sensor 10 are also installed at the water outlet pipe to collect the temperature, pressure and flow rate of the outlet water, respectively. The pressure difference collected by the two temperature and pressure sensors 8 is the system pressure difference. The temperature and pressure sensors 8 and the flow sensor 10 transmit the collected data to the control unit. Vibration sensors 9 are installed in key parts of the liquid cooling system, such as the inlet and outlet pipes of pipe 5 and the bends of pipe 5. Vibration sensors 9 monitor the vibration of these parts in real time and transmit the vibration amplitude data to the control unit. The control unit is connected to the liquid immersion sensor 11, temperature and pressure sensor 8, vibration sensor 9, flow sensor 10, as well as the PCS, water machine and other equipment. It is used to receive signals from each sensor and control the start and stop of the PCS and water machine according to the signals, while sending alarm information to the host computer.

[0019] The liquid cooling plate 3 is tightly attached to the surface of the power device 4 inside the PCS, and the heat generated by the power device 4 is removed by the circulation of the coolant. The pipe 5 is made of high pressure resistant and corrosion resistant material, and connects the liquid cooling plate 3, the air-water heat exchanger 6 and other components to form a closed coolant circulation channel.

[0020] The drip tray 2 is a rectangular structure made of metal and welded to the housing 1, located directly below the quick-connect fitting. Its edges are sealed to prevent liquid leakage. A high-precision liquid immersion sensor 11 is installed inside the drip tray 2. When the liquid level in the drip tray 2 reaches a certain threshold, the liquid immersion sensor 11 can quickly detect it and send an electrical signal. The rational layout and sealing design of the drip tray 2, along with the placement of the drain hole 7, effectively collect and handle leaked liquid, preventing damage to the equipment while ensuring the overall protection level of the machine.

[0021] A drain hole 7 is provided at the bottom of the housing 1. The diameter of the drain hole 7 is determined according to actual needs. A cover plate is installed on the drain hole 7. The cover plate is sealed to the housing 1 by a sealing ring to ensure that the IP rating of the whole machine meets the requirements.

[0022] High-precision temperature and pressure sensors 8 and flow sensors 10 are installed at the inlet and outlet pipes, respectively. The temperature and pressure sensor 8 can accurately collect the temperature and pressure data of the inlet and outlet water in real time, while the flow sensor 10 can measure the flow rate of the coolant in real time and transmit the data to the control unit via a signal line. The control unit uses a high-performance microprocessor, which can quickly process the data transmitted by the immersion sensor 11, temperature and pressure sensor 8, vibration sensor 9, and flow sensor 10, and make judgments and controls according to preset rules.

[0023] Vibration sensors 9 are installed at key locations such as the inlet and outlet pipes of pipe 5 and the bends of pipe 5. The vibration sensors 9 are accelerometer-type sensors that can monitor the vibration of these locations in real time and transmit the vibration amplitude data to the control unit. At the same time, the control unit has a built-in fast Fourier transform algorithm module that can perform real-time spectrum analysis of the vibration signal.

[0024] The power device 4 is arranged at a certain distance from the liquid cooling outlet and inlet to ensure that the water droplets generated by condensation will not flow into the power circuit along the direction of gravity dripping, thereby preventing local short circuits.

[0025] Example 2 like Figure 3 As shown, a monitoring method for a liquid cooling system of an energy storage converter includes the following steps: S1. Acquire monitoring data from the liquid immersion sensor 11, temperature and pressure sensor 8, vibration sensor 9, and flow sensor 10; S2. Based on the monitoring data, determine whether the system is abnormal. If so, reduce the output power of the PCS to a safe power, send an alarm message to the host computer, and proceed to S3. Otherwise, proceed to S1. S3. If the abnormality persists for a certain period of time, shut down the PCS and water chiller, and inspect and repair the liquid cooling system.

[0026] In step S1, data from the liquid immersion sensor 11, temperature and pressure sensor 8, vibration sensor 9, and flow sensor 10 are acquired. Specifically, the liquid immersion sensor 11 monitors in real time whether there is liquid in the water receiving pan 2. When there is a certain amount of water in the water receiving pan 2, the liquid immersion sensor 11 transmits a signal to the control unit. The temperature and pressure sensor 8 collects the temperature and pressure data of the inlet and outlet water pipes in real time and transmits the temperature and pressure data to the control unit. The flow sensor 10 collects the flow data of the inlet and outlet water pipes in real time and transmits the flow data to the control unit. The vibration sensor 9 monitors the vibration of key parts of the liquid cooling system in real time and transmits the vibration amplitude data to the control unit.

[0027] In step S2, the system is assessed for abnormality based on monitoring data. If so, the output power of the PCS is reduced to a safe level, an alarm message is sent to the host computer, and step S3 is executed. Otherwise, step S1 is executed. Specifically, the system is assessed for abnormality based on data from the liquid immersion sensor 11. If the control unit receives a signal from the liquid immersion sensor 11, the system is abnormal. The control unit first controls the reduction of the PCS's output power to a safe level to reduce coolant demand and system pressure, and simultaneously sends an alarm message to the host computer.

[0028] The system is judged to be abnormal based on the monitoring data of temperature and pressure sensor 8 and flow sensor 10. The system pressure difference ΔP and flow rate Q satisfy a quadratic polynomial relationship, as shown in the following expression: △P=aQ 2 +bQ+c In the above formula, ΔP represents the system pressure difference, Q represents the flow rate, and a, b, and c are coefficients obtained by fitting experimental and actual operating data. The larger the flow rate, the larger the pressure difference; when a leak occurs in the system, the flow rate decreases, and the pressure difference decreases.

[0029] Considering the impact of coolant temperature on the system, the temperature correction factor k is adjusted. T Make corrections. Temperature correction factor k T The relationship between the coolant temperature T and the coolant temperature is expressed as follows: In the above formula, k T This is a temperature correction factor. α is the temperature correction factor at the reference temperature T0, and α is the rate of change of the temperature correction factor.

[0030] When calculating the relationship between system pressure difference and flow rate, the system pressure difference is corrected to ΔP′=k T ΔP is used to more accurately reflect the relationship between actual flow rate and pressure difference, thereby improving the accuracy of leak detection. According to the expression ΔP = aQ 2 +bQ+c calculates the flow rate Q corresponding to the current system pressure difference, combined with the temperature correction factor expression k. T =k T0 +α(T-T0) is used to correct the system pressure difference to obtain ΔP′. If the corrected system pressure difference ΔP′ is lower than the normal range [ΔP], then... min ,△P max The control unit first controls the reduction of the PCS output power to a safe level to reduce coolant demand and system pressure, while simultaneously sending an alarm message to the host computer.

[0031] The system is judged based on the monitoring data of flow sensor 10. The expression for calculating the flow rate change δ is as follows: In the above formula, δ is the rate of change of flow rate, and Q n Q represents the flow rate at the current moment. n-1 This represents the flow rate value from the previous moment.

[0032] When the absolute value of the flow rate change rate δ is greater than the set threshold δ0, it is also judged that there may be a leakage. The control unit first controls the reduction of the output power of the PCS to a safe power to reduce the demand for coolant and the system pressure, and at the same time sends an alarm message to the host computer.

[0033] Based on the monitoring data from vibration sensor 9, the system is assessed for abnormalities. To more accurately pinpoint the location of leaks, vibration spectrum analysis is performed. Let the vibration signal acquired by vibration sensor 9 be x(t). A Fast Fourier Transform (FFT) is applied to obtain the vibration signal spectrum X(f), where f is the frequency. The amplitude distribution of different frequency components in the spectrum is analyzed and compared with the spectral characteristics during normal operation. If in a certain frequency range [f...]... min ,f max Within [A], the vibration amplitude change exceeds the set threshold △A, or the vibration amplitude A exceeds the normal range [A]. min A max If the system detects a potential leak near the location of the vibration sensor 9, the control unit first reduces the output power of the PCS to a safe level to decrease coolant demand and system pressure, while simultaneously sending an alarm message to the host computer.

[0034] In step S3, if the abnormality persists within a certain period of time, the PCS and water chiller are shut down to inspect and repair the liquid cooling system. Specifically, if the abnormality does not disappear within a certain period of time, the control unit shuts down the PCS and water chiller. The operator then inspects and repairs the liquid cooling system based on the alarm information from the host computer, eliminating any leaks. After the repairs are completed, the operator resets the system through the control unit to restore the PCS and water chiller to normal operation.

[0035] This invention, by incorporating components such as a water collection tray 2, a liquid immersion sensor 11, a temperature and pressure sensor 8, a vibration sensor 9, and a flow sensor 10, forms a more comprehensive and refined multi-layered leakage monitoring system. It can promptly and accurately detect leakage phenomena in the liquid cooling system from multiple dimensions, including liquid accumulation, pressure and flow rate changes, and vibration characteristics, encompassing both existing leaks and potential leakage risks. This significantly improves the accuracy and reliability of leakage monitoring. The leakage monitoring method based on the relationship between system pressure difference and flow rate, combined with comprehensive analysis of multiple parameters such as flow rate change rate, vibration spectrum analysis, and temperature correction coefficient, can promptly detect problems in the early stages of leakage through richer parameter changes and more accurately determine the leakage location, buying more time for equipment maintenance and reducing equipment damage. When an abnormal situation is detected, the protection strategy of first reducing the PCS output power to a safe level reduces system pressure and coolant demand without immediate shutdown, providing a buffer time to determine whether a complete shutdown is necessary, avoiding unnecessary downtime impacting production, and also helping to prevent further deterioration of the leakage situation, thus improving system stability and reliability.

[0036] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0037] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A monitoring method for a liquid-cooled system of an energy storage converter, characterized in that, Includes the following steps: S1. Acquire monitoring data from the liquid immersion sensor, temperature and pressure sensor, and flow sensor; S2. Based on the monitoring data, determine whether the system is abnormal. If so, reduce the output power of the PCS to a safe power, send an alarm message to the host computer, and proceed to S3. Otherwise, proceed to S1. S3. If the abnormality persists for a certain period of time, shut down the PCS and water chiller, and inspect and repair the liquid cooling system.

2. The monitoring method for a liquid cooling system of an energy storage converter according to claim 1, characterized in that, In S2, if the control unit receives a signal from the liquid immersion sensor, the system is abnormal.

3. The monitoring method for a liquid-cooled system of an energy storage converter according to claim 1, characterized in that, In S2, the system pressure difference and flow rate satisfy a quadratic polynomial relationship, as expressed below: △P=aQ 2 +bQ+c In the above formula, ΔP is the system pressure difference, Q is the flow rate, and a, b, and c are coefficients obtained by fitting experimental and actual operating data; the relationship between the temperature correction coefficient and the coolant temperature is expressed as follows: In the above formula, k T This is a temperature correction factor. Here, α is the temperature correction factor at the reference temperature T0, and α is the rate of change of the temperature correction factor. The system pressure difference is corrected to ΔP′=k T If △P′ is lower than the normal range [△P], min ,△P max If ], then the system is abnormal.

4. The monitoring method for a liquid-cooled system of an energy storage converter according to claim 1, characterized in that, In S2, the expression for calculating the rate of change of flow rate is as follows: In the above formula, δ is the rate of change of flow rate, and Q n Q represents the flow rate at the current moment. n-1 The flow rate value at the previous moment; The system is abnormal when the absolute value of the flow rate change δ is greater than the set threshold δ0.

5. The monitoring method for a liquid cooling system of an energy storage converter according to claim 1, characterized in that, Acquire vibration sensor monitoring data, perform Fast Fourier Transform on the vibration signal collected by the vibration sensor to obtain the spectrum of the vibration signal, analyze the amplitude distribution of different frequency components in the spectrum, and if in a certain frequency range [f min ,f max Within [A], the vibration amplitude A changes beyond the set threshold ΔA or the vibration amplitude A exceeds the normal range [A]. min A max If ], then the system is abnormal.

6. A liquid cooling system for an energy storage converter, applicable to the monitoring method for the liquid cooling system of an energy storage converter as described in any one of claims 1-5, characterized in that, include: Liquid cooling plate, used to dissipate heat from the power devices inside the PCS; Piping is used to form coolant circulation channels and connect to liquid cooling plates; The air-water heat exchanger is used to transfer the heat of the high-temperature air inside the PCS to the coolant, thereby cooling the air and dissipating heat from the power devices inside the PCS. It is connected to the piping. A drip tray is used to collect coolant leaking from the pipes and is located directly below the quick-connect fittings where the pipes, liquid cooling plates, and air-water heat exchangers connect. A liquid immersion sensor is used to monitor the amount of water in the water receiving tray and is installed inside the water receiving tray; Temperature and pressure sensors are used to monitor the temperature and pressure of water entering and leaving the pipeline, and are installed at the inlet and outlet pipes of the pipeline. A flow sensor is used to monitor the flow rate of water entering and leaving a pipeline. It is installed at the inlet and outlet pipes of the pipeline.

7. The liquid cooling system for an energy storage converter according to claim 6, characterized in that, The drip tray is rectangular in shape, made of metal, and welded to the shell. It is located directly below the quick-connect fitting and has sealed edges.

8. The liquid cooling system for an energy storage converter according to claim 7, characterized in that, The bottom of the housing has a drainage hole, which is sealed by a combination of a cover plate and a sealing ring.

9. The liquid cooling system for an energy storage converter according to claim 7, characterized in that, Also includes: Vibration sensors are used to monitor vibration data and are installed at the inlet pipe, outlet pipe, and bends of the pipeline.

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