Microfluidic device for analyzing dissolved gas in insulating oil and control method

Abstract

The invention relates to a microfluidic device for analyzing dissolved gas in insulating oil and a control method. The micro-fluidic device comprises a micro-fluidic chip and a heating device, the micro-fluidic chip is provided with an oil sample inlet, a micro-channel area and a gas-liquid separation area, the oil sample inlet is communicated with the micro-channel area, the micro-channel area is communicated with the gas-liquid separation area, a pump cavity used for containing fluid is formed in the micro-channel area, and the heating device is arranged in the pump cavity. The pump cavity is respectively communicated with the oil sample inlet and the gas-liquid separation area, a piezoelectric brake is arranged in the pump cavity, the piezoelectric brake is connected with an elastic pump membrane of the pump cavity, and the heating device is used for heating the micro-channel area; the piezoelectric brake and the heating device are integrated on the micro-fluidic chip, and the micro-fluidic chip is small in size and high in extraction efficiency.

Description

Technical Field

[0001] This application relates to the field of chemical analysis technology, and in particular to a microfluidic device and control method for analyzing dissolved gases in insulating oil. Background Technology

[0002] During operation, the insulating oil and solid insulating materials inside power transformers and other oil-filled electrical equipment will gradually age and decompose due to electrical and thermal factors, producing a variety of characteristic gases such as hydrogen (H2), acetylene (C2H2), and methane (CH4). These gases dissolve in the insulating oil, and changes in their composition and content can accurately reflect the type and severity of latent faults inside the equipment.

[0003] Therefore, dissolved gas analysis (DGA) is a core technology for diagnosing and assessing the health status of power equipment. However, existing DGA technologies suffer from problems such as large device size and long extraction time. Summary of the Invention

[0004] Therefore, it is necessary to provide a microfluidic device and control method for analyzing dissolved gases in insulating oil that has a small device size and short extraction time, in order to address the above-mentioned technical problems.

[0005] In a first aspect, this application provides a microfluidic device for analyzing dissolved gases in insulating oil, the microfluidic device comprising:

[0006] The microfluidic chip has an oil sample inlet, a microchannel region, and a gas-liquid separation region. The oil sample inlet is connected to the microchannel region, and the microchannel region is connected to the gas-liquid separation region. The microchannel region is provided with a pump chamber for containing fluid. The pump chamber is connected to the oil sample inlet and the gas-liquid separation region, respectively. A piezoelectric brake is provided in the pump chamber and connected to the elastic pump diaphragm of the pump chamber.

[0007] The heating device, integrated on the microfluidic chip, is used to heat the microchannel region.

[0008] In one embodiment, the microchannel region is further provided with:

[0009] The first pipe has one end connected to the oil sample inlet and the other end connected to the pump chamber. The shape of the first pipe is serpentine or spiral. The heating device is used to heat the first pipe, and the heating device and the first pipe are integrated into a single structure using MEMS technology.

[0010] In one embodiment, the pump chamber is provided with:

[0011] The first check valve is connected to the first pipeline and is manufactured using MEMS technology.

[0012] The second check valve connects to the gas-liquid separation area and is manufactured using MEMS technology.

[0013] In one embodiment, the microchannel region is further provided with:

[0014] The second pipeline has one end connected to the second one-way valve and the other end connected to the gas-liquid separation area. The second pipeline is serpentine or spiral in shape and has herringbone grooves or spiral channels inside. The heating device is used to heat the second pipeline, and the heating device and the second pipeline are integrated into a single structure using MEMS technology.

[0015] In one embodiment, the microchannel region is further provided with:

[0016] A flow rate sensing device is installed between the second check valve and the second pipeline.

[0017] In one embodiment, the microchannel region is further provided with:

[0018] The third pipe has one end connected to the other end of the second pipe, and the other end of the third pipe is connected to the gas-liquid separation area. A cavitation array or a first micro-column array is installed inside the third pipe.

[0019] In one embodiment, the gas-liquid separation region is provided with:

[0020] The bifurcated channel includes an inlet, a first outlet, and a second outlet. The inlet is connected to the pump chamber. The first outlet is narrower than the second outlet, and a capillary valve or a second micro-column array is provided at the first outlet.

[0021] Secondly, this application also provides a control method applied to the aforementioned microfluidic device, the method comprising:

[0022] Obtain the flow velocity information corresponding to the fluid flowing out of the pump chamber;

[0023] Based on flow velocity information, a PID closed-loop control algorithm is used to adjust the operating frequency of the piezoelectric brake.

[0024] Thirdly, this application also provides a controller, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described method.

[0025] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0026] The aforementioned microfluidic device and control method for dissolved gas analysis in insulating oil includes a microfluidic chip and a heating device. The microfluidic chip has an oil sample inlet, a microchannel region, and a gas-liquid separation region. The oil sample inlet is connected to the microchannel region, and the microchannel region is connected to the gas-liquid separation region. A pump chamber for containing fluid is provided in the microchannel region, and the pump chamber is connected to both the oil sample inlet and the gas-liquid separation region. A piezoelectric brake is installed inside the pump chamber and connected to the elastic pump diaphragm of the pump chamber. The heating device is used to heat the microchannel region. This application utilizes a piezoelectric brake installed in the pump chamber within the microchannel region. The piezoelectric brake can move the elastic pump diaphragm within the pump chamber, causing the volume of the pump chamber to increase or decrease accordingly, resulting in a change in pressure inside the pump chamber. Fluid is rapidly drawn into or expelled from the pump chamber. The heating device is used to heat the fluid in the microchannel region, making it easier to flow and reducing extraction time. Furthermore, the heating device is integrated onto the microfluidic chip, reducing the size of the microfluidic device. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a structural block diagram of a microfluidic device for dissolved gas analysis in insulating oil in one embodiment;

[0029] Figure 2 This is a schematic diagram of a microfluidic device for analyzing dissolved gases in insulating oil in one embodiment;

[0030] Figure 3 This is a schematic flowchart of a control method for a microfluidic device used for dissolved gas analysis in insulating oil in one embodiment;

[0031] Figure 4 This is a diagram of the internal structure of the controller in one embodiment. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0033] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0034] During operation, the insulating oil and solid insulating materials inside power transformers and other oil-filled electrical equipment will gradually age and decompose due to electrical and thermal factors, producing a variety of characteristic gases such as hydrogen (H2), acetylene (C2H2), and methane (CH4). These gases dissolve in the insulating oil, and changes in their composition and content can accurately reflect the type and severity of latent faults inside the equipment.

[0035] Therefore, dissolved gas analysis (DGA) in oil is a core technology for diagnosing and assessing the health status of power equipment. However, existing DGA technologies typically involve two steps: gas extraction and gas detection. Traditional gas extraction methods, such as headspace analysis, oscillation analysis, and gas chromatography purge-and-trap, generally suffer from the following drawbacks: ① Large device size: Requires large glass containers, oscillators, or complex piping systems, making miniaturization and integration difficult. ② Long extraction time: Usually requires tens of minutes to several hours to reach gas-liquid equilibrium, failing to meet the needs of rapid online monitoring. ③ Large sample volume requirement: Requires oil samples of milliliters (mL) or even larger, which is detrimental to on-site sampling and continuous monitoring. ④ Low automation: Cumbersome operation, requiring manual intervention, and prone to introducing errors.

[0036] The microfluidic device and control method for dissolved gas analysis in insulating oil provided in this application embodiment offer a compact, efficient, and fast-responding microfluidic device for monitoring transformer insulating oil. A piezoelectric brake is installed in the pump chamber within the microchannel region. This piezoelectric brake moves the elastic pump diaphragm within the pump chamber, causing the volume of the pump chamber to increase or decrease accordingly. This results in a change in pressure within the pump chamber, allowing fluid to be rapidly drawn in or expelled. A heating device is used to heat the fluid in the microchannel region, making it easier to flow and reducing extraction time. Furthermore, the heating device is integrated onto the microfluidic chip, reducing the overall size of the microfluidic device.

[0037] In one exemplary embodiment, such as Figure 1 As shown, a microfluidic device for dissolved gas analysis in insulating oil is provided. The microfluidic device includes:

[0038] The microfluidic chip 100 has an oil sample inlet 110, a microchannel region 120, and a gas-liquid separation region 130. The oil sample inlet 110 is connected to the microchannel region 120, and the microchannel region 120 is connected to the gas-liquid separation region 130. The microchannel region 120 is provided with a pump chamber 122 for containing fluid. The pump chamber 122 is connected to the oil sample inlet 110 and the gas-liquid separation region 130, and a piezoelectric brake 124 is provided in the pump chamber 122. The piezoelectric brake 124 is connected to the elastic pump diaphragm of the pump chamber 122.

[0039] The heating device 200, integrated on the microfluidic chip 100, is used to heat the microchannel region 120.

[0040] The type of fluid can be set according to the actual situation. In this embodiment, the fluid is an oil sample to be tested.

[0041] Specifically, such as Figure 1 As shown, the substrate of the microfluidic chip 100 can be made of a material that is chemically inert to insulating oil, such as glass, silicon, or quartz. The gas-liquid separation region 130 can be divided into an oil sample outlet and a gas outlet. The oil sample inlet 110 is used to introduce the oil sample to be tested. The microchannel region 120 is etched or constructed inside the substrate of the microfluidic chip 100, connecting the oil sample inlet 110, the oil sample outlet, and the gas outlet. The channel used for connection is preferably serpentine or spiral-shaped to maximize the channel length within the limited area of ​​the microfluidic chip 100, extend the residence time of the oil sample to be tested in the microfluidic chip 100, and ensure sufficient reaction.

[0042] A pump chamber 122 for containing fluid is provided in the microfluidic region 120. The pump chamber 122 is connected to the oil sample inlet 110 and the gas-liquid separation region 130, respectively. A piezoelectric brake 124 is provided in the pump chamber 122. The piezoelectric brake 124 is deposited or adhered to the elastic pump membrane of the pump chamber 122. When a voltage is applied to the piezoelectric brake 124, it contracts or arches upward due to the inverse piezoelectric effect (depending on its polarization direction and electrode configuration). The piezoelectric brake 124 drives the flexible diaphragm (elastic pump membrane) below it to move upward together. The volume of the pump chamber 122 increases instantaneously, resulting in a decrease in internal pressure and the formation of a negative pressure. Under the action of this pressure difference, the oil sample to be tested is drawn into the pump chamber 122; and vice versa. By driving the piezoelectric brake 124 with a high-frequency AC voltage (usually in the range of several hundred to several thousand hertz), the above "draw-out" cycle is repeated at an extremely high speed. Each cycle pumps out only tiny droplets at the nanoliter (nL) or picoliter (pL) level, but the cumulative effect of high frequency forms a macroscopically continuous and controllable microflow, which facilitates subsequent gas-liquid separation and reduces extraction time.

[0043] The heating device 200 is used to heat the oil sample to be tested flowing in the microchannel region 120. Since the viscosity of the oil sample to be tested is very sensitive to temperature, even a slight increase in temperature can significantly reduce its viscosity, making it "thinner" and easier to flow, thus reducing the extraction time.

[0044] In this embodiment, a piezoelectric brake is provided in the pump chamber in the microfluidic region. The piezoelectric brake can drive the elastic pump membrane in the pump chamber to move together, so that the volume of the pump chamber increases or decreases accordingly, resulting in a change in the pressure inside the pump chamber. The fluid is quickly drawn into or discharged from the pump chamber. The heating device is used to heat the fluid in the microfluidic region, making it easier to flow and reducing the extraction time. Moreover, the heating device is integrated on the microfluidic chip, reducing the volume of the microfluidic device.

[0045] In one embodiment, the microchannel region is further provided with:

[0046] The first pipe has one end connected to the oil sample inlet and the other end connected to the pump chamber. The shape of the first pipe is serpentine or spiral. The heating device is used to heat the first pipe, and the heating device and the first pipe are integrated into a single structure using MEMS technology.

[0047] Specifically, the first pipe is used to connect the oil sample inlet and the pump chamber. In order to maximize the channel length within the limited microfluidic chip area, extend the residence time of the oil sample in the chip and allow it to react fully, the shape of the first pipe is set to be serpentine or spiral. The heating device and the first pipe are integrated into a single structure through MEMS integrated processing technology, which facilitates heating of the oil sample to be tested.

[0048] For example, the heating device can be integrated at the bottom or both sides of the first pipe. The specific type of heating device can be set according to the actual situation. In this embodiment, a micro heater is used as an example for illustration.

[0049] It should be noted that the area where the first pipe is located can serve as a viscosity adjustment zone. After the oil sample to be tested is introduced from the oil sample inlet, it immediately enters the viscosity adjustment zone. Microheaters are integrated at the bottom or on both sides of the flow channel (first pipe) in this zone. These are integrated using MEMS integrated processing technology and can be thin-film resistors (such as platinum, titanium-tungsten alloy / copper, etc.) or liquid metals (such as gallium-indium alloy, etc.). Their heating power can be precisely controlled by an external power supply. After preheating in the viscosity adjustment zone, the oil sample to be tested can be uniformly heated by 5 to 10°C in a short time. Because the viscosity of transformer oil (the oil sample to be tested) is very sensitive to temperature, even a slight increase in temperature can significantly reduce its viscosity, making it "thinner" and easier to flow.

[0050] In this embodiment, a heating device is integrated into the first pipe connecting the oil sample inlet and the pump chamber, which facilitates the flow of the oil sample to be tested and reduces the extraction time. At the same time, the microfluidic device, which is highly integrated and small in size, is made using MEMS technology and can realize online monitoring of gas components.

[0051] In one embodiment, the pump chamber is provided with:

[0052] The first check valve is connected to the first pipeline and is manufactured using MEMS technology.

[0053] The second check valve connects to the gas-liquid separation area and is manufactured using MEMS technology.

[0054] Specifically, the first check valve can be used as the inlet valve of the pump chamber, and the second check valve can be used as the outlet valve of the pump chamber. The piezoelectric brake drives the elastic pump diaphragm below it to move upward together, and the volume of the pump chamber increases instantaneously, resulting in a decrease in internal pressure and the formation of negative pressure. Under the action of this pressure difference, the first check valve is sucked open, while the second check valve is sucked closed more tightly, and fluid is sucked into the pump chamber from the inlet; and vice versa. This will not be elaborated in the embodiments of this application.

[0055] It should be noted that the pump chamber can be considered a fluid pumping region, which consists of a first check valve, a second check valve (including an inlet valve and an outlet valve), a piezoelectric actuator, and the pump chamber. The first and second check valves are fabricated from MEMS cantilever beam structures, and the piezoelectric actuator is deposited or bonded to a flexible diaphragm (elastic pump membrane) at the top of the pump chamber. Applying a voltage to the piezoelectric actuator causes it to contract or arch upwards due to the inverse piezoelectric effect (depending on its polarization direction and electrode configuration). The piezoelectric actuator drives the flexible diaphragm below it to move upwards, instantly increasing the volume of the pump chamber and causing a decrease in internal pressure, creating a negative pressure. Under this pressure difference, the inlet check valve is drawn open, while the outlet check valve is more tightly closed. Fluid is drawn into the pump chamber from the inlet and vice versa. By driving the piezoelectric actuator with a high-frequency AC voltage (typically in the hundreds to thousands of hertz), the above "intake-out" cycle is repeated at extremely high speeds. Each cycle pumps out only tiny droplets at the nanoliter (nL) or picoliter (pL) level, but the cumulative effect of high frequency forms a macroscopically continuous and controllable microfluidic, reducing the amount of sample required.

[0056] In one embodiment, the microchannel region is further provided with:

[0057] The second pipe has one end connected to the second one-way valve and the other end connected to the gas-liquid separation area. The second pipe is serpentine or spiral in shape and has herringbone grooves or spiral channels inside. The heating device is used to heat the first pipe, and the heating device and the first pipe are integrated into a single structure using MEMS technology.

[0058] Specifically, the second pipe is used to connect the pump chamber and the gas-liquid separation area. In order to maximize the channel length within the limited microfluidic chip area, extend the residence time of the oil sample in the chip and allow it to react fully, the shape of the second pipe is set to be serpentine or spiral. There can be multiple heating devices, some of which are integrated on the first pipe and others on the second pipe. The heating devices and the second pipe are integrated into a single structure through MEMS integrated processing technology, which facilitates the heating of the oil sample to be tested. In addition, herringbone grooves or spiral channels are set in the second pipe. When the oil sample to be tested flows through, these structures will induce the fluid (oil sample to be tested) to generate micro eddies perpendicular to the mainstream direction, thereby achieving chaotic mixing of the fluid.

[0059] For example, the heating device can be integrated into the bottom of the second pipe.

[0060] It should be noted that the area where the second pipe is located can serve as a high-efficiency heat transfer and mixing zone. Staggered herringbone microgrooves or three-dimensional spiral channels are designed at the bottom and / or sidewalls of the second pipe. Similar to the viscosity adjustment zone, a micro heater is integrated at the bottom of this zone. When the oil sample to be tested flows through, these structures induce the fluid to generate micro-vortices perpendicular to the mainstream direction, achieving chaotic mixing of the fluid. This breaks the laminar boundary layer, allowing the oil sample to be tested to be heated quickly and uniformly. The heat transfer efficiency is several times higher than that of a straight channel, and local overheating is effectively avoided.

[0061] In this embodiment, a heating device is integrated into the second pipe connecting the pump chamber and the gas-liquid separation area, which facilitates the flow of the oil sample to be tested and reduces the extraction time. In addition, a herringbone groove or spiral channel is provided in the second pipe, which facilitates the rapid and uniform heating of the oil sample to be tested. The heat transfer efficiency is several times higher than that of a straight channel, and local overheating is effectively avoided. At the same time, the microfluidic device is highly integrated and small in size using MEMS technology, which can realize online monitoring of gas components.

[0062] In one embodiment, the microchannel region is further provided with:

[0063] A flow rate sensing device is installed between the second check valve and the second pipeline.

[0064] The specific type of flow velocity sensing device can be set according to the actual situation. In this embodiment, a MEMS pressure sensor or a thermal flow sensor is used as an example for illustration.

[0065] Specifically, the microfluidic device also includes a controller; after the oil sample to be tested flows out from the outlet valve (second check valve), a MEMS pressure sensor or thermal flow sensor is integrated downstream of the pump cavity outlet to detect the flow rate of the fluid at the pump cavity outlet and feed it back to the controller. The controller can use a PID closed-loop control algorithm to adjust the working frequency of the piezoelectric brake, thereby achieving the purpose of controlling the outlet flow rate and making the flow rate more uniform.

[0066] In one embodiment, the microchannel region is further provided with:

[0067] The third pipe has one end connected to the other end of the second pipe, and the other end of the third pipe is connected to the gas-liquid separation area. A cavitation array or a first micro-column array is installed inside the third pipe.

[0068] Specifically, the third pipe connects the second pipe and the gas-liquid separation area. The area where the third pipe is located can serve as a nucleation region, following the high-efficiency heat transfer mixing region. The inner surface of the third pipe is arrayed with micron-sized artificial cavities or sharp micropillar arrays through laser or etching processes. These artificial defects or micropillars provide a large number of bubble nucleation points, allowing dissolved gases in the oil sample to occur controllably and stably at these preset locations. The third pipe can be appropriately widened to reduce the flow rate, so that the microbubbles have enough time to grow and collide and coalesce into larger bubbles.

[0069] In this embodiment, the third pipe connects the second pipe and the gas-liquid separation area. A cavitation array or a first microcolumn array is provided in the third pipe, so that the dissolved gas in the oil sample to be tested can be generated in a controllable and stable manner at these preset positions, thereby improving the extraction efficiency.

[0070] In one embodiment, the gas-liquid separation region is provided with:

[0071] The bifurcated channel includes an inlet, a first outlet, and a second outlet. The inlet is connected to the pump chamber. The first outlet is narrower than the second outlet, and a capillary valve or a second micro-column array is provided at the first outlet.

[0072] Specifically, the bifurcation channel can be Y-shaped or T-shaped. The first outlet can be used as a gas outlet, and the second outlet can be used as an oil sample outlet. Due to its continuity and surface tension, the liquid phase oil sample will naturally tend to continue flowing along the main liquid phase channel (wider flow channel), while the gas outlet branch channel is narrower and a capillary valve or hydrophobic microcolumn array (second microcolumn array) should be installed at the outlet to prevent the liquid phase from flowing in. Thus, gas-liquid separation is achieved.

[0073] To facilitate understanding by those skilled in the art, a specific example is provided below to illustrate the microfluidic device, such as... Figure 2 As shown, it includes a microfluidic chip and a heating device integrated on the microfluidic chip (not shown). Figure 2 As shown in the figure, the microfluidic chip has an oil sample inlet, a microchannel region, and a gas-liquid separation region. The microchannel region includes a viscosity adjustment region, a fluid pumping region, a high-efficiency heat transfer mixing region, and a nucleation region. The specific descriptions of each region are as shown above and will not be repeated here.

[0074] like Figure 2 As shown, the oil sample to be tested passes through the oil sample inlet, the fluid pumping area, the high-efficiency heat transfer mixing area and the nucleation area in sequence before entering the gas-liquid separation area to achieve gas-liquid separation.

[0075] It is understood that microfluidic devices, by employing microfluidic technology, can achieve rapid gas-liquid separation of samples with controllable process. At the same time, compared with current oil chromatography devices, this application integrates functional units (heating, temperature control, pumping, and separation) onto a centimeter-sized microfluidic chip, which has the advantages of small size, light weight, and low power consumption, and can be applied to portable or distributed online monitoring systems. In addition, the controller inside the microfluidic device can control the heating temperature of the heating device and the voltage of the piezoelectric actuator, so that the temperature and flow rate of the oil sample to be tested are controllable, ensuring the accuracy and repeatability of extraction.

[0076] In one exemplary embodiment, such as Figure 3 As shown, a control method is provided, applied to the aforementioned microfluidic device, the method comprising:

[0077] S302, obtain the flow velocity information corresponding to the fluid flowing out of the pump chamber.

[0078] Specifically, the microfluidic device may include a controller, which is connected to a heating device, a flow rate sensor, and a piezoelectric actuator. The flow rate sensor acquires the flow rate information corresponding to the fluid flowing out of the pump chamber and outputs the flow rate information to the controller.

[0079] S304 uses a PID closed-loop control algorithm to adjust the operating frequency of the piezoelectric brake based on flow velocity information.

[0080] Specifically, based on the received flow velocity information, the controller uses a PID closed-loop control algorithm to adjust the operating frequency of the piezoelectric actuator, thereby achieving the purpose of controlling the fluid flow velocity and making the flow velocity more uniform.

[0081] For example, the controller can also adjust the heating temperature of the heating device according to preset temperature information, which will not be elaborated in the embodiments of this application.

[0082] In the above control method, the driving voltage or driving frequency of the piezoelectric brake is controlled by the PID algorithm to ensure that the flow rate of the oil sample is stable and accurate. That is, the whole process can run automatically under the drive of the controller without manual intervention, which improves the reliability of the detection.

[0083] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0084] Based on the same inventive concept, this application also provides a control device for implementing the control method described above. The solution provided by this device is similar to the solution described in the above method; therefore, specific limitations in one or more control device embodiments provided below can be found in the limitations of the control method described above, and will not be repeated here.

[0085] In one exemplary embodiment, a control device is provided, the device comprising:

[0086] The acquisition module is used to acquire the flow velocity information corresponding to the fluid flowing out of the pump cavity;

[0087] The adjustment module is used to adjust the operating frequency of the piezoelectric brake based on the flow velocity information and using a PID closed-loop control algorithm.

[0088] Each module in the aforementioned control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0089] In one exemplary embodiment, a controller (computer device) is provided, which may be a server, and its internal structure diagram may be as follows: Figure 4As shown, the computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs stored in the non-volatile storage media. The database stores data such as flow rate information. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a control method for a microfluidic device.

[0090] Those skilled in the art will understand that Figure 4 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0091] In one exemplary embodiment, a controller is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the control method of the microfluidic device described above.

[0092] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the control method of the microfluidic device described above.

[0093] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the control method of the microfluidic device described above.

[0094] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0095] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0096] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0097] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A microfluidic device for analyzing dissolved gases in insulating oil, characterized in that, The microfluidic device includes: A microfluidic chip has an oil sample inlet, a microchannel region, and a gas-liquid separation region. The oil sample inlet is connected to the microchannel region, and the microchannel region is connected to the gas-liquid separation region. A pump chamber for containing fluid is provided in the microchannel region. The pump chamber is connected to the oil sample inlet and the gas-liquid separation region, respectively. A piezoelectric brake is provided in the pump chamber and connected to the elastic pump diaphragm of the pump chamber. A heating device, integrated on the microfluidic chip, is used to heat the microchannel region.

2. The microfluidic device according to claim 1, characterized in that, The microchannel region is also provided with: A first conduit, one end of which is connected to the oil sample inlet and the other end of which is connected to the pump chamber, wherein the shape of the first conduit is serpentine or spiral; wherein, the heating device is used to heat the first conduit, and the heating device and the first conduit are integrated into a single structure using MEMS technology.

3. The microfluidic device according to claim 2, characterized in that, The pump chamber is provided with: A first one-way valve is connected to the first pipeline, and the first one-way valve is manufactured using the MEMS process. The second one-way valve is connected to the gas-liquid separation area, and the second one-way valve is manufactured using the MEMS process.

4. The microfluidic device according to claim 3, characterized in that, The microchannel region is also provided with: The second pipe has one end connected to the second one-way valve and the other end connected to the gas-liquid separation area. The second pipe is serpentine or spiral in shape and has herringbone grooves or spiral channels inside. The heating device is used to heat the second pipe, and the heating device and the second pipe are integrated into a single structure using MEMS technology.

5. The microfluidic device according to claim 4, characterized in that, The microchannel region is also provided with: A flow rate sensing device is installed between the second check valve and the second pipeline.

6. The microfluidic device according to claim 4, characterized in that, The microchannel region is also provided with: A third conduit, one end of which is connected to the other end of the second conduit, and the other end of which is connected to the gas-liquid separation region, wherein a cavitation array or a first micro-column array is provided inside the third conduit.

7. The microfluidic device according to claim 1, characterized in that, The gas-liquid separation region is equipped with: The bifurcated channel includes an inlet, a first outlet, and a second outlet. The inlet is connected to the pump chamber. The first outlet is narrower than the second outlet, and a capillary valve or a second micro-column array is provided at the first outlet.

8. A control method, characterized in that, The method, applied to the microfluidic device according to any one of claims 1 to 7, comprises: Obtain the flow velocity information corresponding to the fluid flowing out of the pump cavity; Based on the flow velocity information, a PID closed-loop control algorithm is used to adjust the operating frequency of the piezoelectric brake.

9. A controller comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method of claim 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the method of claim 8.

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