Process measurement and control instrument

Abstract

The utility model relates to the technical field of process measurement and control, in particular to a process measurement and control instrument. The process measurement and control instrument comprises a measuring tube, a micro electro mechanical system chip and a rectification assembly, a fluid connection interface of the process measurement and control instrument is compatible with a fluid connection interface of the variable-area flowmeter and is connected to two ends of the measuring tube; the rectification assembly and the micro-electro-mechanical system chip are both installed in the measuring tube, and the rectification assembly and the micro-electro-mechanical system chip are sequentially arranged in the flow direction of fluid. The rectifying assembly is used for rectifying fluid, and the micro electro mechanical system chip is provided with a thermal mass flow sensor. The process measurement and control instrument provided by the utility model can replace a variable-area flowmeter to be applied in an industrial field, the measurement is not influenced by temperature and pressure changes, and the resolution ratio and the precision are high; various media can be measured and controlled, the control range is wide, and the cost is equivalent to that of a traditional variable-area flowmeter; in addition, digitization and remote data transmission / measurement and control are realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to process measurement and control technical field, specifically, relate to a process measurement and control instrument. BACKGROUND

[0002] In industrial production, various fluids are commonly used as production raw materials. Currently, the technology for measuring and controlling fluids is mechanical variable area flowmeter (commonly known as rotor flowmeter). However, for the increasing precise measurement and control, such equipment cannot measure the influence of temperature and pressure changes on fluids, and the measurement range is limited to a narrow range by mechanical principles. In addition, the digital conversion of variable area flowmeter usually adopts photoelectric technology, which has high cost and requires external power supply. Therefore, the variable area flowmeter cannot meet the actual needs of current industrial site measurement and control.

[0003] Micro-electro-mechanical system (MEMS) chips using a manufacturing method similar to large-scale integrated circuits provide the possibility of reducing manufacturing costs, low-power measurement and transmitting multiple process control parameters. However, current flow process measurement and control products usually have strict installation requirements, which makes it difficult for existing micro-electro-mechanical system flow products to replace variable area flowmeters in industrial sites (especially without straight pipe section structure). Therefore, in the current industrial internet of things process measurement and control application, it is difficult to obtain flow measurement process control in large scale. UTILITY MODEL CONTENT

[0004] The purpose of the utility model is to provide a process measurement and control instrument to solve the technical problem that the rotor flowmeter widely used in the prior art cannot directly provide digital and mass flow measurement and control, and has high cost.

[0005] The process measurement and control instrument provided by the utility model comprises a measuring pipe, a micro-electro-mechanical system chip and a rectifying assembly.

[0006] The fluid connection interface of the process measurement and control instrument is compatible with the fluid connection interface of the variable area flowmeter and is connected to the measuring pipe.

[0007] The rectifying assembly and the micro-electro-mechanical system chip are both installed in the measuring pipe, and the rectifying assembly is arranged on the fluid inlet side of the micro-electro-mechanical system chip; the rectifying assembly is used for rectifying the fluid, and the micro-electro-mechanical system chip is provided with a plurality of sensors, which include one or more of a thermal mass flow sensor, a temperature sensor and a pressure sensor.

[0008] Preferably, as an implementable manner, the rectifying assembly comprises a flow breaking disc and a rectifying cavity, the flow breaking disc is arranged at the inlet end of the rectifying cavity, the central axis of the flow breaking disc and the central axis of the rectifying cavity both coincide with the central axis of the measuring pipe, and there is an annular gap between the flow breaking disc and the measuring pipe.

[0009] Preferably, as an implementable manner, the rectifying cavity comprises a straight pipe section, a standard straight flow device and a standard rectifier, the standard straight flow device is arranged at the inlet end of the straight pipe section, and the standard rectifier is arranged at the outlet end of the straight pipe section.

[0010] And / or, the flow breaking disc comprises a flat plate which is perpendicular to the central axis of the rectifying cavity.

[0011] Preferably, as an implementable manner, the ratio of the diameter of the flow breaking disc to the inner diameter of the measuring pipe is greater than or equal to 5 / 8.

[0012] And / or, the ratio of the length of the straight pipe section to the inner diameter of the measuring pipe is greater than or equal to 3.

[0013] Preferably, as an implementable manner, the rectifying assembly further comprises a flow regulator arranged at the outlet end of the rectifying cavity for adjusting the full scale of the measured flow.

[0014] And / or, the full scale of the process measuring and control instrument is any value in the range of 10sccm to 200slpm.

[0015] Preferably, as an implementable manner, the process measuring and control instrument further comprises a data transmission assembly, the micro-electro-mechanical system chip is in communication connection with the Internet of Things through the data transmission assembly, and the data transmission assembly is used for transmitting the measurement signal of the micro-electro-mechanical system chip to the Internet of Things.

[0016] Preferably, as an implementable manner, the data transmission assembly comprises a wired data transmission interface.

[0017] And / or, the data transmission assembly comprises one or more of a Bluetooth module, a narrowband Internet of Things module, a mobile communication module, a WIFI module and a long-distance radio module.

[0018] Preferably, as an implementable manner, the process measuring and control instrument further comprises a processor which is electrically connected with the micro-electro-mechanical system chip and is used for converting the measurement signal of the micro-electro-mechanical system chip into a digital signal.

[0019] The process measuring and control instrument further comprises a display which is electrically connected with the processor and is used for displaying the values of the parameters measured by the micro-electro-mechanical system chip; and / or the processor is used for alarming when the parameter values measured by the micro-electro-mechanical system chip are out of limits.

[0020] Preferably, as an implementable manner, the micro-electro-mechanical system chip is further provided with a temperature sensor and / or a pressure sensor.

[0021] Preferably, as an implementable mode, the process measurement and control instrument is provided with a manual flow regulating valve for regulating the flow of fluid;

[0022] And / or, the process measurement and control instrument is provided with a battery assembly;

[0023] And / or, the thermal mass flow sensor is aligned with the center of the measuring pipe;

[0024] And / or, the surface of the thermal mass flow sensor is parallel to the fluid flow direction;

[0025] And / or, the process measurement and control instrument is provided with a menu key for viewing or resetting the cumulative flow, selecting the medium of the measured fluid, setting the limit value of the flow alarm, setting the limit value of the leakage detection, viewing the alarm data and / or setting the password.

[0026] Compared with the prior art, the process measurement and control instrument has the beneficial effects that:

[0027] The process measurement and control instrument provided by the utility model discloses, set up as the fluid connecting interface compatible with the traditional variable area flowmeter, can not change the installation structure of the traditional process measurement and control product, satisfy the current field process measurement and control design scheme and use habit, thereby, the process measurement and control instrument provided by the utility model discloses, can directly replace the traditional variable area flowmeter and install to the corresponding position, the thermal mass flow sensor in the micro electro mechanical system chip set in the measuring pipe can sense the flow of the fluid flowing through the measuring pipe.

[0028] It should be noted that the measurement method of the thermal mass flow sensor is thermal mass flow sensing technology, which is not affected by environmental temperature and pressure, guarantees the requirements of high precision, repeatability and high resolution, and can be specifically implemented; The thermal mass flow sensor can also realize digital measurement of fluid flow. Compared with the variable area flowmeter which needs to obtain the fluid flow by manual visual inspection, the data reading accuracy is higher, and it has obvious advantages for more accurate industrial process measurement and control, and the cost is comparable to that of the variable area flowmeter; It can also measure and control a variety of media, and the control range is wide; In addition, the resolution of the adjustment is higher than that of the mechanical type, and the accuracy of the measured quantity can be improved by more than 3 orders of magnitude.

[0029] The utility model discloses a rectifier assembly is set up to the position of the fluid to the side of micro electro mechanical system chip in the measuring pipe, utilizes the rectifier assembly to handle the fluid, leads the fluid with repeatable flow distribution to the measuring point of micro electro mechanical system chip, can guarantee the stability and repeatability of measurement measurement, like this, can guarantee the accuracy of each parameter value measured by micro electro mechanical system chip;At the same time, the setting of rectifier assembly can also reduce the flow resistance and pressure loss, and can significantly reduce the probability of flow blockage, and reduce the requirement to the measured pipeline system.

[0030] Therefore, the process measurement and control instrument provided by this utility model can replace the variable area flow meter in industrial applications. The measurement is not affected by temperature and pressure changes, and it has high resolution and accuracy. It can measure and control a variety of media, has a wide control range, and its cost is comparable to that of traditional variable area flow meters. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0032] Figure 1 A schematic diagram of the structure of the process measurement and control instrument provided in this embodiment of the present invention in the state without the battery assembly installed;

[0033] Figure 2 A schematic diagram of the structure of the process measurement and control instrument provided in the embodiment of this utility model with the battery pack installed;

[0034] Figure 3 A structural schematic diagram of the process measurement and control instrument provided in this embodiment of the utility model, in the state without the battery component installed;

[0035] Figure 4 Another perspective structural diagram of the process measurement and control instrument provided in the embodiment of this utility model with the battery assembly installed;

[0036] Figure 5 An exploded structural diagram of the process measurement and control instrument provided in this embodiment of the utility model.

[0037] Explanation of reference numerals in the attached figures:

[0038] 100 - Measuring tube; 110 - Top cover; 120 - Bottom cover;

[0039] 200 - Microelectromechanical system chip; 210 - Processor;

[0040] 300 - Rectifier assembly; 310 - Flow disc; 320 - Rectifier cavity; 330 - Flow regulator;

[0041] 400 - Fluid connection interface; 410 - Fluid inlet interface; 420 - Fluid outlet interface; 430 - Flow channel module; 440 - Threaded connector; 450 - Retaining screw ring; 460 - First rubber washer; 470 - Third rubber washer; 480 - Screw assembly; 490 - Nut assembly;

[0042] 510 - Wired data transmission interface; 520 - Communication circuit;

[0043] 600 - Monitor;

[0044] 700 - Manual flow control valve; 710 - Valve core; 720 - Second rubber washer; 730 - Nut; 740 - Screw; 750 - Direction indicator; 760 - Adjustment handle;

[0045] 800 - Battery assembly; 810 - Battery holder; 820 - Power interface circuit board; 830 - Battery cover; 840 - Battery;

[0046] 900 - Menu key. Detailed Implementation

[0047] Traditional variable area flow meters (VAWs) are widely used in industrial field control due to their advantages of requiring no external power source / supply, easy installation, and manual control. However, the measurement values ​​of VAWs require manual visual inspection, which often varies from person to person, making accurate measurement impossible. Furthermore, the measurement values ​​of VAWs are affected by temperature and pressure changes, and their measurement range is limited to a narrow range due to mechanical principles. They can only provide a single instantaneous flow parameter and cannot obtain real-time cumulative flow, detect on-site leaks, or provide early warning of exceeding safety limits. They also cannot provide remote data transmission or require expensive electromechanical / photoelectric conversion equipment. Therefore, VAWs can no longer meet current practical needs, and for the Industrial Internet of Things (IIoT), they cannot directly obtain effective data to achieve IoT functions. This application aims to address the difficulty in scalably obtaining digital measurement quantities of flow control process quantities in current IIoT process measurement and control applications. It designs an easily manufactured VAW that can directly and seamlessly replace traditional VAWs, has multiple enhanced functions, and can be scalably adopted in IIoT applications.

[0048] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0049] The present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0050] See Figures 1-5This embodiment provides a process measurement and control instrument, which includes a measuring tube 100, a microelectromechanical system (MEMS) chip 200, and a rectifier assembly 300. The fluid connection interface 400 of the process measurement and control instrument is compatible with the fluid connection interface of a variable area flow meter and is connected to both ends of the measuring tube 100. The rectifier assembly 300 and the MEMS chip 200 are both installed inside the measuring tube 100 and are arranged sequentially along the fluid flow direction. The rectifier assembly 300 is used to rectify the fluid, and the MEMS chip 200 is provided with several sensors, including one or more of a thermal mass flow sensor, a temperature sensor, and a pressure sensor.

[0051] The process control instrument provided in this embodiment has its fluid connection interface 400 configured to be compatible with the fluid connection interface of a traditional variable area flow meter. This allows for seamless replacement without altering the installation structure of traditional process control products, meeting current on-site process control design schemes and usage habits. Therefore, the process control instrument provided in this embodiment can directly replace a traditional variable area flow meter in the corresponding location. The thermal mass flow sensor in the microelectromechanical system chip 200 located within the measuring tube 100 can sense the flow rate of the fluid flowing through the measuring tube 100. The thermal mass flow sensor uses thermal mass flow sensing technology, which is unaffected by ambient temperature and pressure, ensuring high accuracy, repeatability, and high resolution, and is readily implementable. Furthermore, the thermal mass flow sensor enables digital measurement of fluid flow rate. Compared to variable area flow meters that require manual visual inspection to obtain fluid flow rate, it offers higher data reading accuracy, providing a clear advantage for more precise industrial process control, while maintaining a cost comparable to variable area flow meters. It can also control various media, offering a wide control range.

[0052] Traditional variable area flow meters typically rely on visual measurement for fluid control. Measurements are often subjective and vary from person to person. Furthermore, the range and resolution of flow adjustment are limited by the mechanical scale on the glass tube, making high-resolution adjustment impossible. This poses a challenge to achieving digital and precise flow control, especially in low-flow or precision-critical applications. Such limitations can lead to inefficiency, poor process performance, or failure to meet required flow specifications, or even the inability to achieve generally accurate and repeatable measurements. The process control instrument provided in this embodiment employs microelectromechanical system (MEMS) chip-based digital measurement, replacing manual visual inspection and completely solving this problem. Its adjustment resolution is significantly higher than that of mechanical methods, and the accuracy of the measurement can be improved by more than three orders of magnitude.

[0053] Traditional variable area flow meters are vertically installed, with the fluid connection interface perpendicular to the measuring tube. These flow meters determine the instantaneous flow rate by the position of a float in the measuring tube supported by the fluid; therefore, the fluid's flow state has little impact on the results. However, in this embodiment, the sensors in the microelectromechanical system chip 200 determine the flow rate, temperature, and pressure of the fluid flowing through the entire measuring tube 100 by the position of a single point within the measuring tube 100. Therefore, this measurement point needs to have good stability and repeatability. Furthermore, the fluid connection interface 400 of the process control instrument provided in this embodiment is set perpendicular to the measuring tube 100 to be compatible with the fluid connection interface of the variable area flow meter. This layout exacerbates the uncertainty of fluid distribution. In this embodiment, a rectifier assembly 300 is placed inside the measuring tube 100 at the fluid-to-flow side of the microelectromechanical system chip 200. The rectifier assembly 300 processes the fluid, guiding it with a repeatable flow rate distribution to the measuring point of the microelectromechanical system chip 200. This ensures the stability and repeatability of the measurement, thereby guaranteeing the accuracy of the parameters measured by the microelectromechanical system chip 200. At the same time, the rectifier assembly 300 also reduces flow resistance and pressure loss, and significantly reduces the probability of flow blockage, thus reducing the requirements on the pipeline system under test.

[0054] Therefore, the process measurement and control instrument provided in this embodiment can replace the variable area flow meter in industrial field applications. The measurement is not affected by temperature and pressure changes, and has high resolution and accuracy. It can measure and control a variety of media, has a wide control range, and its cost is comparable to that of traditional variable area flow meters.

[0055] The fluid connection interface 400 of the process measurement and control instrument provided in this embodiment is compatible with the fluid connection interface of a traditional variable area flow meter, at least in terms of the spacing / size of the inlet and outlet.

[0056] At the application level, when the process measurement and control instrument provided in this embodiment is applied to the Internet of Things (IoT) process measurement and control environment, it can acquire flow measurement process control quantities on a large scale, serving as the basis for big data analysis of the IoT. Because it can provide effective measurement and control parameters with high accuracy, it can improve the effectiveness and practicality of the IoT and meet the requirements of current refined production.

[0057] The MEMS chip 200 employs the traditional thermal mass flow detection principle, integrating the capillary resistance wire of a traditional thermal sensor onto a single chip using a process similar to large-scale integrated circuits as the measurement sensing element. Furthermore, fluid physical and thermal parameters such as thermal conductivity can also be included within the chip's measurement parameter range. Since thermal conductivity is closely related to the physical properties of gases, it can be used to measure the concentration of two-component gases.

[0058] In the specific structure of the rectifier assembly 300, a flow-breaking disk 310 and a rectifier cavity 320 can be provided. The flow-breaking disk 310 is set at the inlet end of the rectifier cavity 320, and the central axis of the flow-breaking disk 310 and the central axis of the rectifier cavity 320 are both set to coincide with the central axis of the measuring tube 100. An annular gap is reserved between the flow-breaking disk 310 and the measuring tube 100. Depending on the conditions of the inlet connection pipe, the fluid entering the measuring tube 100 can have any flow state. It will directly impact the disk surface of the flow-breaking disk 310. The flow-breaking disk 310 will force the flowing fluid to redistribute along its edge and then converge in the rectifier cavity 320. That is, the flow-breaking disk 310 is used to forcibly redistribute the flow state and flow field of the fluid entering the measuring tube 100. The rectifier cavity 320 can guide the fluid with repeatable flow distribution to the measurement point of the microelectromechanical system chip 200, thereby ensuring the stability and repeatability of the measurement of the microelectromechanical system chip 200.

[0059] Specifically, the rectifier cavity 320 mainly consists of three parts: a straight pipe section, a standard DC converter, and a standard rectifier. The standard DC converter is placed at the inlet end of the straight pipe section, and the standard rectifier is placed at the outlet end of the straight pipe section. The ratio of the length of the straight pipe section to the inner diameter of the measuring tube 100 can be set to be greater than or equal to 3, which can better ensure the measurement accuracy of the microelectromechanical system chip 200.

[0060] Specifically, the flow-breaking plate 310 may include a flat plate, which is configured to be perpendicular to the central axis of the flow-rectifying cavity 320.

[0061] Specifically, the ratio of the diameter of the flow-breaking plate 310 to the inner diameter of the measuring tube 100 can be set to greater than or equal to 5 / 8, preferably 7 / 8.

[0062] A flow guide ring can also be provided in the rectifier assembly 300.

[0063] In the specific structure of the rectifier assembly 300, a flow regulator 330 can also be provided. The flow regulator 330 is positioned at the outlet end of the rectifier cavity 320. The flow regulator 330 can be used to adjust the full-scale range of the measured flow rate according to application requirements, offering strong scalability and applicability in different pipelines. It is also easy to maintain and replace. Specifically, the full-scale range of the process control instrument can be set to any value from 10 sccm to 200 slpm.

[0064] This embodiment also includes a data transmission component, which connects the microelectromechanical system (MEMS) chip 200 to the Internet of Things (IoT) for communication. The data transmission component transmits the measurement signals of the MEMS chip 200 to the IoT, enabling remote data transmission. This allows the IoT to directly acquire valid data measured by process control instruments, thus achieving IoT functionality. A communication circuit 520 may be included in the data transmission component.

[0065] Specifically, the data transmission component can employ one or both of wired and wireless transmission methods.

[0066] When using wired transmission, a wired data transmission interface 510 can be installed on the process control instrument to transmit data via a wired connection. Specifically, the wired data transmission port 510 can adopt a standard USB-C interface, providing the standard data transmission format of RS485 Modbus commonly used in industry.

[0067] When using wireless transmission, one or more of the following modules can be installed on the process control instrument: Bluetooth module, narrowband IoT module, mobile communication module, WIFI module, and long-range radio module. The appropriate wireless transmission module can be selected according to the specific requirements.

[0068] In this embodiment, a processor 210 may also be provided, which is electrically connected to the microelectromechanical system (MEMS) chip 200 to convert the measurement signals of the MEMS chip 200 into digital signals. Specifically, the processor 210 can convert the measurement signals into digital signals through an analog-to-digital converter, amplify them, and then output the corresponding parameter values. The processor 210 can also calculate the cumulative flow rate based on the acquired instantaneous flow rate value and the clock.

[0069] A display 600 can also be installed on the process control instrument. The display 600 is electrically connected to the processor 210 to display the values ​​of various parameters measured by the microelectromechanical system chip 200, such as instantaneous flow rate, fluid temperature, fluid pressure, and barcodes indicating flow rate. Compared with the traditional variable area flow meter's method of visually judging parameter values ​​by the position of the float, the numerical display provides more accurate and intuitive readings. The display 600 may include a backlit liquid crystal display (LCD) screen, which uses a vertical display method to ensure compatibility with traditional variable area flow meters and adapt to user habits.

[0070] Limit values ​​corresponding to the values ​​of each monitored parameter can be set in the processor 210. When the parameter value measured by the microelectromechanical system chip 200 exceeds the limit, the processor 210 can sound an alarm. It can detect the status of the monitored pipeline / flow channel and has an alarm function when a fault occurs. Specifically, it can monitor the upper and lower limits of the measured quantity and monitor fluid leakage, realize on-site safety measurement and control of leakage, and promptly detect on-site faults such as overflow, overpressure, and blockage, so as to avoid process control failure and other safety accidents.

[0071] Temperature sensors and / or pressure sensors can also be set on the microelectromechanical system chip 200. The temperature sensor can sense the temperature of the fluid, and the pressure sensor can sense the pressure of the fluid. Thus, multi-parameter data acquisition can be realized, and more complete process control parameters can be obtained. These parameters are very important for process control. Compared with the variable area flow meter, which can only obtain a single instantaneous fluid flow rate, the process measurement and control instrument provided in this embodiment has obvious advantages for more accurate industrial process digitization and big data measurement and control.

[0072] The process control instrument provided in this embodiment can also be equipped with a manual flow regulating valve 700. This manual flow regulating valve 700 can regulate the flow rate of the fluid. The manual adjustment method is compatible with the mechanical manual flow control structure of traditional variable area flow meters, and can be adapted to the user's habits. The manual flow regulating valve 700 can be a needle valve.

[0073] The process control instrument provided in this embodiment uses a battery assembly 800 as its power source. Therefore, this process control instrument is suitable for situations where there is no external power supply at the monitoring site, achieving compatibility with the power requirements of traditional mechanical variable area flow meters. The battery assembly 800 can power the process control instrument through the aforementioned wired data transmission port 510. The battery assembly 800 consists of a battery holder 810, a power interface circuit board 820, a battery cover 830, and a battery 840. The power interface is preferably a Type-C plug. The battery 840 can be a lithium battery ER14250. When there is no data transmission, the battery 840 has a lifespan of more than 6 months; when wireless data transmission is required, the transmission mode is intermittent to ensure the working life of the battery 840.

[0074] The process measurement and control instrument provided in this embodiment features a microelectromechanical system chip 200 and a low-power design for the overall circuit. The average current required for the sensor chip to operate does not exceed 100 microamps, thus allowing the use of a small, inexpensive 1200mAh lithium battery or a corresponding rechargeable battery to ensure more than six months of operation.

[0075] Preferably, the thermal mass flow sensor is aligned with the center of the measuring tube 100, as the fluid velocity is fastest at the center of the flow channel, which increases the sensitivity of the thermal mass flow sensor. Alternatively, the pressure and temperature sensors can also be aligned with the center of the measuring tube 100 to increase their sensitivity.

[0076] Furthermore, the surface of the thermal mass flow sensor can be set parallel to the fluid flow direction to reduce the impact force of the fluid on the thermal mass flow sensor. Similarly, the surfaces of both the pressure sensor and the temperature sensor can be set parallel to the fluid flow direction to reduce the impact force of the fluid on the pressure sensor and the temperature sensor, respectively.

[0077] A menu key 900 can be set on the process control instrument. This menu key 900 can be used to: view or reset the cumulative flow, select the medium of the measured fluid, set the limit value of the flow alarm, set the limit value of the leak detection, view alarm data and / or set a password.

[0078] The process measurement and control instrument provided in this embodiment is applicable to process measurement and control of various fluid media, which can be gas or liquid; specifically, the measured and controlled medium can be switched online or remotely.

[0079] In fact, there are two fluid connection interfaces 400, namely a fluid inlet interface 410 and a fluid outlet interface 420. In the specific structure of both fluid connection interfaces 400, a flow channel module 430 and a threaded connector 440 can be set. The threaded connector 440 is fixed to the flow channel module 430 by a fixing screw ring 450. A first leak-proof rubber gasket 460 can be set between the fixing screw ring 450 and the flow channel module 430.

[0080] The manual flow control valve 700 can be installed above the flow channel module 430 of the fluid inlet interface 410. Before placing the valve core 710, a second rubber gasket 720 is placed on the flow channel module 430 and then secured with a nut 730. The adjustment handle 760 is secured to the nut 730 with a screw 740, and then the adjustment direction indicator 750 is glued to the adjustment handle 760.

[0081] The flow channel module 430 is connected to the measuring tube 100 via the third rubber gasket 470, screw group 480 and nut group 490.

[0082] The measuring body and processor 210 can be protected by the upper cover 110 and the lower cover 120.

[0083] The process monitoring and control instrument provided in this embodiment can meet the requirements of digital remote transmission, low power consumption, multiple parameters, high precision, low pressure loss, and leakage detection. The process monitoring and control instrument provided in this embodiment adopts the same mechanical dimensions and installation flow channel interface as traditional variable area flow meters, making its installation method the same as that of traditional variable area flow meters, and allowing it to be used for installation in confined spaces.

[0084] In the description of this utility model, it should be noted that the terms "vertical" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0085] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A process measurement and control instrument, characterized in that, Includes measuring tubes, microelectromechanical system chips, and rectifier components; The fluid connection interface of the process measurement and control instrument is compatible with the fluid connection interface of the variable area flow meter and is connected to the measuring tube; Both the rectifier assembly and the microelectromechanical system (MEMS) chip are installed inside the measuring tube, and the rectifier assembly is located on the fluid inflow side of the MEMS chip; the rectifier assembly is used to rectify the fluid, and the MEMS chip is equipped with a thermal mass flow sensor.

2. The process measurement and control instrument according to claim 1, characterized in that, The rectifier assembly includes a flow-breaking plate and a rectifier cavity. The flow-breaking plate is located at the inlet end of the rectifier cavity. The central axis of the flow-breaking plate and the central axis of the rectifier cavity are both coincident with the central axis of the measuring tube, and there is an annular gap between the flow-breaking plate and the measuring tube.

3. The process measurement and control instrument according to claim 2, characterized in that, The rectifier cavity includes a straight pipe section, a standard DC converter, and a standard rectifier. The standard DC converter is located at the inlet end of the straight pipe section, and the standard rectifier is located at the outlet end of the straight pipe section. And / or, the flow-breaking plate includes a flat plate perpendicular to the central axis of the rectifier cavity.

4. The process measurement and control instrument according to claim 3, characterized in that, The ratio of the diameter of the flow-breaking plate to the inner diameter of the measuring tube is greater than or equal to 5 / 8; And / or, the ratio of the length of the straight pipe section to the inner diameter of the measuring pipe is greater than or equal to 3.

5. The process measurement and control instrument according to claim 2, characterized in that, The rectifier assembly also includes a flow regulator, which is located at the outlet end of the rectifier cavity and is used to adjust the full scale of the measured flow rate. And / or, the full scale of the process measurement and control instrument is any value between 10 sccm and 200 slpm.

6. The process measurement and control instrument according to claim 1, characterized in that, The process measurement and control instrument also includes a data transmission component. The microelectromechanical system chip communicates with the Internet of Things (IoT) through the data transmission component. The data transmission component is used to transmit the measurement signals of the microelectromechanical system chip to the IoT.

7. The process measurement and control instrument according to claim 6, characterized in that, The data transmission component includes a wired data transmission interface; And / or, the data transmission component includes one or more of a Bluetooth module, a narrowband IoT module, a mobile communication module, a WIFI module, and a long-range radio module.

8. The process measurement and control instrument according to claim 1, characterized in that, The process measurement and control instrument also includes a processor, which is electrically connected to the microelectromechanical system chip and is used to convert the measurement signals of the microelectromechanical system chip into digital signals; The process measurement and control instrument also includes a display, which is electrically connected to the processor and is used to display the values ​​of various parameters measured by the microelectromechanical system chip; and / or, the processor is used to issue an alarm when the parameter values ​​measured by the microelectromechanical system chip exceed the limits.

9. The process measurement and control instrument according to claim 1, characterized in that, The microelectromechanical system chip is also equipped with a temperature sensor and / or a pressure sensor.

10. The process measurement and control instrument according to any one of claims 1-9, characterized in that, The process control instrument is equipped with a manual flow regulating valve, which is used to regulate the flow rate of the fluid. And / or, the process control instrument is equipped with a battery assembly; And / or, the thermal mass flow sensor is aligned with the center of the measuring tube; And / or, the surface of the thermal mass flow sensor is parallel to the direction of fluid flow; And / or, the process control instrument is equipped with a menu key, which is used for: viewing or resetting the cumulative flow, selecting the medium of the measured fluid, setting the limit value of the flow alarm, setting the limit value of the leak detection, viewing alarm data and / or setting a password.

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