A pressure-reducing entropy gas flowmeter and flow controller

Abstract

The present application belongs to the technical field of gas flow measurement and control, and particularly relates to a pressure-reducing entropy change type gas flow meter and flow controller. The pressure-reducing entropy change type gas flow meter and flow controller comprise a body, a sensor group and a control center. The body is internally provided with a gas passage. A throttling element is arranged in the gas passage. The flow area of the throttling element is smaller than that of the gas passage. The throttling element causes the gas flowing through the gas passage to generate pressure drop and temperature difference change when passing through the throttling element. The throttling element separates the gas passage into a compression cavity upstream thereof and an expansion cavity downstream thereof. The present application solves the high-purity requirement of the original thermal gas mass flow meter and thermal gas mass flow controller, and can be used in industrial grade and food grade. The present application has simple structure, is suitable for batch manufacturing, greatly reduces the manufacturing cost of the mass flow meter and mass flow controller, and has outstanding service performance and long service life.

Description

Technical Field

[0001] This invention belongs to the field of gas flow metering and control technology, specifically relating to a depressurization entropy variable gas flow meter and flow controller. Background Technology

[0002] In the field of gas flow meters and flow controllers, the accuracy of common traditional structures on the market is generally not high. For example, the accuracy of worm gear structures can reach ±5%, and the accuracy of Karman vortex street structures can generally be between ±3% and ±5%. Moreover, they all measure volumetric flow rate. To convert volumetric flow rate to mass flow rate, external pressure and temperature sensors must be used for cumbersome temperature and pressure compensation. Conventional turbine or Karman vortex street flow meters often contain mechanical moving parts or complex vortex generator structures, such as turbine bearings that are prone to wear and aging. When dealing with small gas flow rates, such structures will experience significant signal attenuation and a sharp increase in measurement deviation in the low-range section due to mechanical friction torque or excessively low Reynolds number. They are also highly susceptible to interference from pipeline mechanical vibration.

[0003] High-precision mass flow controllers employ thermal mass flow controllers (MFC), also known as capillary metal tube thermoelectric mass flow controllers. These controllers use gas entering a stainless steel capillary tube, and calculate the mass flow rate by sensing the temperature difference through a heating / temperature measuring coil wound around the tube. While the accuracy of such thermal mass flow controllers or thermal mass flow meters can reach ±1%, the inner diameter of the capillary metal tube is only tens of micrometers, making it difficult to manufacture. The small orifice size also makes it prone to clogging, resulting in poor serviceability. Poor serviceability refers to a device or product that is too cumbersome to maintain during daily use, has a high failure rate, is extremely difficult to clean or repair, or has overly demanding requirements for the working environment and supporting facilities.

[0004] The principle of a temperature difference-based mass flow controller is to calculate the mass flow rate based on the temperature difference, power, and specific heat capacity of the gas. Its core formula is: or , Indicates heating power. It is the mass flow rate of the gas. It is the specific heat capacity of the gas. It's the temperature difference.

[0005] Thermoelectric calculations for gas flow rates are extremely sensitive to gas purity, particularly the water vapor content, because nitrogen has a specific heat capacity of 1.04. The specific heat capacity of carbon dioxide is 0.84. The specific heat capacity of water vapor is 1.864. The purity of carbon dioxide is far greater than that of common gases, and the presence of water vapor in the gas will severely affect its accuracy. Furthermore, the heating wire is typically made of precious metals such as platinum, resulting in high costs. Therefore, its application is limited to scenarios requiring extremely high purity gas media and high environmental cleanliness (such as photovoltaics, semiconductors, and chip manufacturing). The semiconductor industry requires gas purity >99.999999%, and the photovoltaic industry requires gas purity >99.9999%. It is difficult to apply to work scenarios with lower purity requirements and harsher operating conditions, such as petroleum, chemical, welding, and cutting industries. The price of gases varies greatly depending on their purity. For example, industrial-grade 99% carbon dioxide costs only 400-700 yuan / ton, food-grade 99.9% costs 800-1200 yuan / ton, 99.9999% costs 45,000-75,000 yuan / ton, and 99.999999% is even more expensive.

[0006] Therefore, there is an urgent need for a gas mass flow controller that can use industrial-grade / food-grade gas purity to achieve precise mass flow control and accurate measurement of mass flow. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, the present invention provides a decompression entropy variable gas flow controller.

[0008] The technical solution of the present invention is as follows: it includes a main body, a sensor group and a control center. The main body is provided with a gas channel, and a throttling element is provided in the gas channel. The flow cross-sectional area of ​​the throttling element is smaller than the flow cross-sectional area of ​​the gas channel. The throttling element causes the gas flowing through the gas channel to generate pressure drop and temperature difference changes when passing through the throttling element. The throttling element divides the gas channel into a compression chamber located upstream and an expansion chamber located downstream.

[0009] The sensor group is disposed on the body and is used to collect the thermodynamic parameters of the gas before and after passing through the throttling element; the sensor group includes at least a pre-hole sensor that is connected to or adjacent to the compression chamber and a post-hole sensor that is connected to or adjacent to the expansion chamber.

[0010] The data from both the sensor before and after the orifice are transmitted to the control center, which then calculates and outputs or displays the flow rate.

[0011] Preferably, the flow cross-sectional area of ​​the throttling element exhibits a structure that first decreases and then increases.

[0012] Preferably, the body and the throttling element are integrally formed or separately assembled; when they are separately assembled, the throttling element is fixedly installed in the gas channel by at least one of the following methods: threaded engagement, snap-fit, interference fit, welding, or adhesive fixation.

[0013] Preferably, a protective cover is also installed on the main body, and the main body, throttling element and protective cover are all made of metal materials, such as copper, stainless steel and other materials.

[0014] Preferably, the pre-orifice sensor includes a pre-orifice pressure sensor for acquiring the compression chamber pressure and a pre-orifice temperature sensor for acquiring the compression chamber temperature. The post-orifice sensor includes a post-orifice temperature sensor for acquiring the expansion chamber temperature.

[0015] Preferably, the post-hole sensor further includes a post-hole pressure sensor for acquiring the pressure in the expansion chamber.

[0016] Preferably, the tube wall of the main body is provided with a first mounting hole communicating with the compression chamber and a second mounting hole communicating with the expansion chamber. The pressure sensor and the temperature sensor before the hole are fixedly installed at the first mounting hole, and the pressure sensor and the temperature sensor after the hole are fixedly installed at the second mounting hole and the second mounting hole is closed.

[0017] Preferably, the acquisition end of the pre-hole temperature sensor extends into the flow channel of the compression chamber, and the acquisition end of the post-hole temperature sensor extends into the flow channel of the expansion chamber; the acquisition end of the pre-hole pressure sensor does not extend into the flow channel of the compression chamber but is only connected to the flow channel of the compression chamber, and the acquisition end of the post-hole pressure sensor does not extend into the flow channel of the expansion chamber but is only connected to the flow channel of the expansion chamber.

[0018] Preferably, the acquisition ends of the in-orifice pressure sensor and the in-orifice temperature sensor both extend into the flow channel of the compression chamber, and the acquisition ends of the out-of-orifice pressure sensor and the out-of-orifice temperature sensor both extend into the flow channel of the expansion chamber.

[0019] Preferably, the depressurization entropy variable gas flow meter further includes an atmospheric pressure sensor and an atmospheric temperature sensor. The acquisition ends of the atmospheric pressure sensor and the atmospheric temperature sensor are both directly exposed to the external natural ambient air. The data from the atmospheric pressure sensor and the atmospheric temperature sensor are both transmitted to the control center.

[0020] Preferably, both the air inlet and air outlet of the main body are equipped with quick-connect interfaces, and an air inlet pressure sensor is installed at the air inlet.

[0021] Preferably, the control center includes at least one of a microcontroller, a digital signal processor (DSP), a programmable logic array (FPGA), a microprocessor, a programmable logic controller (PLC), or an industrial computer.

[0022] Preferably, the main body has a filter element installed at the inlet of the gas channel.

[0023] A heat insulation component is installed in the first mounting hole where the pre-hole temperature sensor is located, and a heat insulation component is installed in the second mounting hole where the post-hole temperature sensor is located. The pre-hole pressure sensor is installed on the first mounting hole by means of threads or snap-fit, and the post-hole pressure sensor is installed on the second mounting hole by means of threads or snap-fit. The intake pressure sensor is installed on the gas passage by means of threads or snap-fit.

[0024] To overcome the shortcomings of the prior art, the present invention provides a pressure-reducing entropy-variable gas flow controller. The technical solution of the present invention is as follows: a control valve is installed at the front end of the compression chamber in the gas channel, the control center controls the opening degree of the control valve, and the control center adjusts the opening degree of the control valve in real time according to the comparison between the calculated real-time flow and the target flow.

[0025] Preferably, the control valve is a proportional solenoid valve.

[0026] This invention addresses the high purity requirements of traditional thermal gas mass flow meters and controllers, enabling their use in industrial and food-grade applications. It features a simple structure, suitability for mass production, and significantly reduces manufacturing costs. Furthermore, it boasts excellent serviceability and a long service life. The use of all-metal materials for the body, throttling elements, and protective cover enhances overall strength and lifespan, while also making it suitable for environments with strong electromagnetic interference. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the present invention.

[0028] Figures 2-5 This is an exploded view of the present invention.

[0029] Figure 6 This is an exploded view of the present invention with the control center, protective cover, and support removed.

[0030] Figures 7-8 This is a schematic diagram of the structure of the present invention without the control center, protective cover and support.

[0031] Figure 9 This is a cross-sectional view of the structure of Embodiment 1 of the present invention with the control center, protective cover and support removed.

[0032] Figure 10This is a cross-sectional view of the structure of Embodiment 2 of the present invention with the control center, protective cover and support removed.

[0033] Figure 11 This is a three-dimensional sectional view of Embodiment 2 of the present invention with the control center, protective cover, and support removed.

[0034] Figure 12 This is a schematic diagram of the structure of the main body in Embodiment 2 of the present invention.

[0035] Figure 13 This is a three-dimensional sectional view of the main body of Embodiment 2 of the present invention.

[0036] Figures 14-15 This is a schematic diagram of the structure of the gas flow meter of the present invention.

[0037] Figures 16-20 This is a schematic diagram of the structure of various structures of the throttling element of the present invention.

[0038] Figures 1-20 In the middle, 1. Body, 11. Gas passage, 111. Compression chamber, 112. Expansion chamber, 12. First mounting hole, 13. Second mounting hole, 14. Inlet end, 15. Outlet end, 16. Marking, 17. Filter element, 2. Throttling element, 30. Inlet pressure sensor, 31. Pressure sensor before the hole, 32. Pressure sensor after the hole, 33. Snap connector, 41. Temperature sensor before the hole, 42. Temperature sensor after the hole, 43. Heat insulation component, 5. Quick-connect interface, 6. Control center, 7. Control valve, 71. Proportional solenoid valve inlet hole, 72. Proportional solenoid valve outlet hole, 8. Protective cover, 9. Bracket Detailed Implementation

[0039] The embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0040] Table of key symbols in the instruction manual:

[0041] symbol meaning symbol meaning mass flow Temperature difference Standard volumetric flow rate Comprehensive reference coefficient under sonic congestion flow conditions Target quality flow Comprehensive reference coefficient under subsonic flow conditions Flow error adiabatic index of gas Intake absolute pressure Temperature correction factor Absolute pressure before the flow-limiting short orifice Gas standard operating condition density Absolute pressure after the flow-limiting short orifice Heating power absolute atmospheric pressure Specific heat capacity of gases Ambient atmospheric absolute temperature Absolute temperature before the flow-limiting short orifice Absolute temperature after the flow-limiting short orifice

[0042] like Figures 1-20 As shown, this embodiment provides a pressure-reducing entropy-variable gas flow meter, including a body 1, a sensor group, and a control center 6. The body 1 has a gas channel 11 inside, and a throttling element 2 is provided in the gas channel 11. The flow cross-sectional area of ​​the throttling element 2 is smaller than the flow cross-sectional area of ​​the gas channel 11. The throttling element 2 causes the gas flowing through the gas channel 11 to generate pressure drop and temperature difference changes when passing through the throttling element 2. The throttling element 2 divides the gas channel 11 into a compression chamber 111 located upstream and an expansion chamber 112 located downstream.

[0043] The sensor group is disposed on the body 1 and is used to collect the thermodynamic parameters of the gas before and after passing through the throttling element 2. The sensor group includes at least a pre-hole sensor that is connected to or adjacent to the compression chamber 111 and a post-hole sensor that is connected to or adjacent to the expansion chamber 112.

[0044] The data from both the sensor before and after the orifice are transmitted to the control center 6, which then calculates and outputs or displays the flow rate.

[0045] The specific calculation method or formula for traffic flow is as follows:

[0046] When the actual pressure ratio satisfies When the fluid is determined to be in a sonic choke flow state, the sonic choke flow flow rate calculation formula is executed.

[0047] When the actual pressure ratio satisfies When the fluid is determined to be in a subsonic flow state, the subsonic flow rate calculation formula is executed.

[0048] The formula for calculating the sonic choke flow rate is as follows: ,

[0049] The formula for calculating the subsonic flow rate is as follows:

[0050]

[0051] in The adiabatic index of the gas is . The absolute pressure before the flow-limiting short orifice. This refers to the absolute pressure after the flow-limiting short orifice.

[0052] Comprehensive reference coefficient under sonic congestion flow conditions Comprehensive reference coefficient under subsonic flow conditions It can be done , Calculate the initial theoretical values.

[0053] The It is a temperature correction factor, derived from actual measurements.

[0054] Since some users are accustomed to using standard volumetric flow rate, mass flow rate can be used instead. Convert to standard volumetric flow rate ,according to Formula conversion.

[0055] Secondly, in order to eliminate the overall manufacturing tolerances of the system and obtain extremely high measurement accuracy, this embodiment recommends placing the initially estimated flow meter in a high-precision sonic nozzle standard device or a high-precision weighing standard gas flow source for multi-point linkage calibration: during system initialization, N sets of preset standard stepped mass flow rates, N ≥ 3, are introduced, and the controller synchronously records the corresponding absolute pressure before the orifice. Absolute pressure after the hole and absolute temperature in front of the hole Absolute temperature after the hole For sonic congestion flow conditions, multiple sets of collected data are substituted into the linear mapping formula, and the least squares method is used to minimize the sum of squared residuals, thereby inversely calculating the most realistic comprehensive benchmark coefficient under the current hardware. The solidified calibration value; similarly, under the subsonic operating condition calibration point, the comprehensive reference coefficient is calculated by inversion. The curing calibration value. Determined by this calibration method. and The coefficient can unify and cancel out mechanical tolerances and sensor nonlinear errors, thereby ensuring that the mass flow measurement accuracy of this invention can still be stably within ±1% in the harsh working conditions of industrial / food grade low-purity gas, and the high-precision version can achieve a mass flow measurement accuracy of within ±0.5% in the entire range.

[0056] To facilitate the Joule-Thomson effect in the gas, the flow cross-sectional area of ​​the throttling element 2 preferably has a structure that first decreases and then increases. This allows the gas flowing through the gas channel 11 to experience a pressure drop and temperature difference as it passes through the throttling element 2, eliminating the need for active heating as required by a thermal mass flow controller (MFC).

[0057] Preferably, the body 1 and the throttling element 2 are either integrally molded or separately assembled. An integrally molded structure is more suitable for plastic structures, as it facilitates mass production using molds. While separately assembled structures are also suitable for plastic materials, they are more suitable for metal materials because they are easier to process and install.

[0058] When it is a split assembly structure, the throttling element 2 is fixedly installed in the gas channel 11 by at least one of the following methods: threaded pair, snap-fit, interference fit, welding or adhesive fixation.

[0059] Preferably, a protective cover 8 is also installed on the main body 1. The main body 1, the throttling element 2, and the protective cover 8 are all made of metal materials, such as copper or stainless steel. This invention adopts an all-metal structure, which can enhance the overall strength and is suitable for use in environments with strong electromagnetic interference.

[0060] Preferably, the in-orifice sensor includes an in-orifice pressure sensor 31 for collecting the pressure of the compression chamber 111 and an in-orifice temperature sensor 41 for collecting the temperature of the compression chamber 111. The post-orifice sensor includes a post-orifice temperature sensor 42 for collecting the temperature of the expansion chamber 112. For products designed to operate under conditions of sonic congestion, since the post-orifice pressure cannot affect the in-orifice pressure, and the post-orifice pressure is not used in the flow calculation formula, the post-orifice pressure sensor 32 can be omitted.

[0061] Preferably, the post-orifice sensor further includes a post-orifice pressure sensor 32 for acquiring the pressure in the expansion chamber 112. For products suitable for both sonic choke flows and subsonic flows, installing the post-orifice pressure sensor 32 broadens the applicability of the product of this invention.

[0062] To facilitate the installation of the pre-hole pressure sensor 31, post-hole pressure sensor 32, pre-hole temperature sensor 41, and post-hole temperature sensor 42, preferably, the pipe wall of the body 1 is provided with a first mounting hole 12 communicating with the compression chamber 111 and a second mounting hole 13 communicating with the expansion chamber 112. The pre-hole pressure sensor 31 and the pre-hole temperature sensor 41 are respectively fixedly installed at the first mounting hole 12, and the post-hole pressure sensor 32 and the post-hole temperature sensor 42 are respectively fixedly installed at the second mounting hole 13 and the second mounting hole 13 is closed. The first mounting hole 12 and the second mounting hole 13 can be through holes or threaded holes, etc. Figures 3-8 and Figures 10-11 The pressure sensor 31 before the hole and the pressure sensor 32 after the hole are installed by means of the snap-fit ​​connector 33.

[0063] Preferably, the acquisition end of the pre-orifice temperature sensor 41 extends into the flow channel of the compression chamber 111, and the acquisition end of the post-orifice temperature sensor 42 extends into the flow channel of the expansion chamber 112; the acquisition end of the pre-orifice pressure sensor 31 does not extend into the flow channel of the compression chamber 111 but is only connected to the flow channel of the compression chamber 111, and the acquisition end of the post-orifice pressure sensor 32 does not extend into the flow channel of the expansion chamber 112 but is only connected to the flow channel of the expansion chamber 112. Since pressure can be transmitted well, the pressure sensor can accurately measure even if it is not located inside the gas channel 11. However, the temperature sensor's measurement error increases with distance from the target. Therefore, it is recommended that the acquisition ends of the pre-orifice temperature sensor 41 and the post-orifice temperature sensor 42 extend into the gas channel 11 to reduce temperature measurement error.

[0064] Alternatively, a preferred installation method is provided, wherein the acquisition ends of the in-hole pressure sensor 31 and the in-hole temperature sensor 41 are both inserted into the flow channel of the compression chamber 111, and the acquisition ends of the in-hole pressure sensor 32 and the in-hole temperature sensor 42 are both inserted into the flow channel of the expansion chamber 112.

[0065] Preferably, both the air inlet end 14 and the air outlet end 15 of the main body 1 are equipped with quick-connect interfaces 5, and an air inlet pressure sensor 30 is installed at the air inlet end 14.

[0066] To enable the product of this invention to have zero-point calibration and maximum range correction functions, preferably, the depressurization entropy variable gas flow meter also includes an atmospheric pressure sensor and an atmospheric temperature sensor. The acquisition ends of the atmospheric pressure sensor and the atmospheric temperature sensor are directly exposed to the external ambient air. The data from the atmospheric pressure sensor and the atmospheric temperature sensor are transmitted to the control center 6. The atmospheric pressure sensor and the atmospheric temperature sensor are not shown in the accompanying drawings. The atmospheric pressure sensor and the atmospheric temperature sensor can be installed in many locations, including the outer periphery of the main body 1, the protective cover 8, etc. The atmospheric pressure sensor and the atmospheric temperature sensor can also be installed in other places, as long as the corresponding feedback signal is transmitted to the control center 6. Even in places where the products of this invention are used in batches in the same location, only one atmospheric pressure sensor and one atmospheric temperature sensor can be installed, and the data from the atmospheric pressure sensor and the atmospheric temperature sensor can be transmitted to the control center of all products of this invention.

[0067] For a system consisting of multiple flow meters and multiple flow controllers, multiple products of this invention can even share a single control center 6 and be uniformly controlled by the single control center 6.

[0068] The zero-position reset method: The control valve 7 is in a preset micro-opening state, and the intake pressure of the intake pressure sensor 30 is... Fluctuation, the absolute pressure before the orifice of the orifice pressure sensor 31 The absolute pressure after the orifice of the orifice pressure sensor 32 A pressure difference initially exists, and the absolute temperature at the inlet of the orifice is measured by the inlet temperature sensor 41. and the absolute temperature after the hole of the temperature sensor 42 A temperature difference begins to exist, at which point the zero point returns to zero.

[0069] The maximum range correction method is as follows: the opening of the control valve 7 is gradually increased until the intake pressure of the intake pressure sensor 30 is reached. The absolute pressure before the hole of the pressure sensor 31 The absolute pressure after the orifice of the pressure sensor 32 Atmospheric pressure sensor ambient atmospheric absolute pressure The pressure difference between them no longer changes, while the absolute temperature of the ambient air at the atmospheric temperature sensor remains constant. The absolute temperature at the inlet of the hole is measured by the inlet temperature sensor 41. and the absolute temperature after the hole of the temperature sensor 42 The temperature difference between the two sides no longer changes, and the flow rate is at its maximum.

[0070] Preferably, the control center 6 includes at least one of a microcontroller, a digital signal processor (DSP), a programmable logic array (FPGA), a microprocessor, a programmable logic controller (PLC), or an industrial computer. Any chip with computing capabilities can serve as the control center 6.

[0071] Furthermore, in order to make this device suitable for low-purity gas environments and effectively intercept sudden large particulate impurities, such as... Figure 6 , Figure 9 , Figure 10 As shown, the main body 1 is provided with a filter element 17 at the air inlet end of the gas channel 11.

[0072] In this embodiment, the filter element 17 is preferably a sintered copper powder filter element with a conical structure. Specifically, the filter element 17 is assembled with the cone tip facing the inlet of the gas channel 11. Based on this conical orientation design, when airflow containing impurities passes through, large particles and dust impacting the conical surface will slide to both sides under the shear force of the airflow, rather than accumulating directly in the center of the windward side. Compared to traditional flat-bottomed or reverse-conical structures, this design significantly reduces the dead zone on the windward side, utilizes airflow to assist in dust removal, thereby greatly improving the filter element's dirt-holding capacity and service life.

[0073] To improve the temperature measurement accuracy of the inlet temperature sensor 41 and the outlet temperature sensor 42, preferably, a heat insulation component 43 is installed in the first mounting hole 12 where the inlet temperature sensor 41 is located, and a heat insulation component 43 is installed in the second mounting hole 13 where the outlet temperature sensor 42 is located. The inlet pressure sensor 31 is installed on the first mounting hole 12 by means of threads or snap-fit, the outlet pressure sensor 32 is installed on the second mounting hole 13 by means of threads or snap-fit ​​connector 33, and the intake pressure sensor 30 is installed on the gas passage 11 by means of threads or snap-fit ​​connector 33.

[0074] The heat insulation component 43 can effectively isolate the body 1 from the measurement interference of the front-hole temperature sensor 41 and the rear-hole temperature sensor 42, thereby improving the measurement accuracy.

[0075] To overcome the shortcomings of the prior art, the present invention provides a pressure-reducing entropy-variable gas flow controller. The technical solution of the present invention is as follows: a control valve 7 is installed at the front end of the compression chamber 111 in the gas channel 11, and the control center 6 controls the opening degree of the control valve 7. The control center 6 adjusts the opening degree of the control valve 7 in real time according to the comparison between the calculated real-time flow and the target flow.

[0076] The flow controller is based on the flow measurement of the above-mentioned flow meter, and then the opening of the control valve 7 is adjusted by the control center 6 so that the actual flow rate is at least the same as the target flow rate.

[0077] To better and faster control of flow rate, the control valve 7 is preferably a proportional solenoid valve. A proportional solenoid valve is a control element that can continuously and proportionally adjust the valve opening, flow rate, or pressure according to the input electrical signal. The flow characteristics of the proportional solenoid valve are close to direct proportion, which helps to control the flow rate more accurately and also reduces the amount of calculation required by the control center 6.

[0078] To help consumers identify the direction of gas flow and prevent users from connecting the gas in the wrong direction, it is preferable to make a mark 16 on the main body 1. The mark 16 can be an arrow, a symbol, or the like.

[0079] like Figure 14 and Figure 15 This is a schematic diagram of the gas flow meter of the present invention, only... Figure 15 The throttling element 2 in the middle is installed and fixed by thread.

[0080] Figure 16 and Figure 17 These are throttling elements 2 with the same structure; one is a perspective view, and the other is a cross-sectional view. Of course, throttling element 2 can also be... Figures 18-20 Due to the large number of structures, these interfaces are not listed one by one. Specific Implementation Example 1:

[0082] A pressure-reducing entropy-variable gas flow controller with flow measurement function. Its specific structure is as follows:

[0083] like Figure 9 As shown, the system includes a main body 1, a sensor group, and a control center 6. The main body 1 has a gas channel 11 inside, and a throttling element 2 is provided in the gas channel 11. The flow cross-sectional area of ​​the throttling element 2 is smaller than the flow cross-sectional area of ​​the gas channel 11. The throttling element 2 causes the gas flowing through the gas channel 11 to experience pressure drop and temperature difference changes when passing through the throttling element 2. The throttling element 2 divides the gas channel 11 into a compression chamber 111 located upstream and an expansion chamber 112 located downstream.

[0084] A control valve 7 is installed at the front end of the compression chamber 111 in the gas passage 11. The control valve 7 is a proportional solenoid valve. The control center 6 controls the opening of the control valve 7. The control valve 7 is installed by drilling two holes above the gas passage 11. One hole is the inlet hole 71 of the proportional solenoid valve, and the other hole is the outlet hole 72 of the proportional solenoid valve.

[0085] The compression chamber 111 is fitted with a pre-orifice pressure sensor 31 and a pre-orifice temperature sensor 41 through two first mounting holes 12, respectively. The expansion chamber 112 is fitted with a post-orifice pressure sensor 32 and a post-orifice temperature sensor 42 through two second mounting holes 13, respectively. An intake pressure sensor 30 is also installed at the front end of the proportional solenoid valve.

[0086] A heat insulation component 43 is installed in both the first mounting hole 12 of the temperature sensor 41 before the mounting hole and the second mounting hole 13 of the temperature sensor 42 after the mounting hole. The heat insulation component 43 prevents the temperature of other components from affecting the accurate measurement of the temperature sensor 41 before the hole and the temperature sensor 42 after the hole.

[0087] The control center 6 is mounted on the main body 1 via a bracket 9. The main body 1 is also equipped with a protective cover 8 to protect many components. The main body 1 and the throttling element 2 adopt a separate assembly structure. The main body 1, the throttling element 2, the protective cover 8, and the bracket 9 are all made of metal materials, generally copper and stainless steel. The specific material selection depends on the gas used, as some gases may be better suited to one of these materials.

[0088] The main body 1 is also equipped with an atmospheric pressure sensor and an atmospheric temperature sensor. The acquisition ends of the atmospheric pressure sensor and the atmospheric temperature sensor are directly exposed to the external natural ambient air. The data from the atmospheric pressure sensor and the atmospheric temperature sensor are transmitted to the control center 6.

[0089] The bottom of the main body 1 is also provided with mounting feet 10. The mounting feet 10 are fixed to the main body 1 by bolts. Then, the product of the present invention can be conveniently fixed and installed in the required position through other holes of the mounting feet 10.

[0090] When used as a flow meter, it is set to flow meter mode within control center 6. Since the use of a screen, buttons, and even signal transmission to control center 6 are standard techniques, they will not be elaborated upon here. Control center 6 then uses the collected inlet pressure... and post-hole pressure and the adiabatic index of the gas To determine whether the current flow is a sonic congestion or a subsonic flow, the corresponding calculation formula is selected. The coefficients in the calculation formula come from pre-stored data, and the pressure and temperature are derived from real-time measured absolute pressure and absolute temperature values.

[0091] The calculated traffic is displayed on the screen or output to other devices.

[0092] Meanwhile, a filter element 17 is installed at the inlet of the gas channel 11, that is, in the quick-connect interface 5 at the inlet of the gas channel 11. Of course, a coarse filter can also be used to filter the gas before it enters the gas channel 11.

[0093] When used as a flow controller, the control center 6 is set to flow meter mode. The control center 6 compares the calculated real-time flow with the set target flow value and adjusts the opening of the proportional solenoid valve in real time until the real-time flow matches the set target flow value. When the real-time flow deviates slightly from the set target flow value due to various other reasons, the opening of the proportional solenoid valve can also be dynamically adjusted in real time to achieve precise flow control. Specific Implementation Example 2:

[0095] Specific Embodiment Two makes the following structural optimizations based on Specific Embodiment One to adapt to high-flow, fast-response operating conditions.

[0096] like Figure 6 and Figures 10-13 As shown, to address the issue of excessive flow resistance in a single valve orifice under high pressure and high flow conditions, the original set of proportional solenoid valve inlet orifices 71 was replaced with two symmetrically arranged sets of proportional solenoid valve inlet orifices 71. This dual-orifice parallel flow-dividing design significantly expands the total flow cross-sectional area of ​​a single valve without increasing the volume of the proportional solenoid valve, effectively reducing local flow resistance and resulting in a pressure loss of the controller exceeding 30% in the high flow range.

[0097] Meanwhile, the intake pressure sensor 30, the pre-hole pressure sensor 31, and the post-hole pressure sensor 32 no longer use a direct threaded insertion method. Instead, they are all assembled by plugging into the first mounting hole 12 and the second mounting hole 13 of the main body 1 using standard industrial snap-fit ​​connectors 33 with O-ring seals (or quick-release pins). This structure significantly improves the assemblability of the entire machine and the efficiency of digital mass production, and greatly facilitates the quick plug-and-play repair and service replacement of individual sensors in the after-sales field. It is also more suitable for the installation methods of conventional pressure sensors on the market.

[0098] This embodiment should not be considered as a limitation of the invention, but any improvements made based on the spirit of the invention should be within the protection scope of the invention.

Claims

1. A pressure-reducing entropy-variable gas flow meter, characterized in that: The system includes a main body (1), a sensor group, and a control center (6). The main body (1) has a gas channel (11) inside. The gas channel (11) has a throttling element (2) inside. The flow cross-sectional area of ​​the throttling element (2) is smaller than the flow cross-sectional area of ​​the gas channel (11). The throttling element (2) causes the gas flowing through the gas channel (11) to experience pressure drop and temperature difference changes when passing through the throttling element (2). The throttling element (2) divides the gas channel (11) into a compression chamber (111) located upstream and an expansion chamber (112) located downstream. The sensor group is disposed on the body (1) and is used to collect the thermodynamic parameters of the gas before and after passing through the throttling element (2); the sensor group includes at least a pre-hole sensor that is connected to or adjacent to the compression chamber (111) and a post-hole sensor that is connected to or adjacent to the expansion chamber (112). The data from the sensor before the hole and the data from the sensor after the hole are both transmitted to the control center (6), which then calculates and outputs or displays the flow rate.

2. The decompression entropy variable gas flow meter according to claim 1, characterized in that: The control center (6) includes at least one of a microcontroller, a digital signal processor (DSP), a programmable logic array (FPGA), a microprocessor, a programmable logic controller (PLC), or an industrial computer.

3. The decompression entropy variable gas flow meter according to claim 1, characterized in that: The main body (1) has a filter element (17) installed at the inlet of the gas channel (11).

4. The decompression entropy variable gas flow meter according to claim 1, characterized in that: The flow cross-sectional area of ​​the throttling element (2) first decreases and then increases. The body (1) and the throttling element (2) are integrally formed or separately combined. When it is a separately combined structure, the throttling element (2) is fixedly installed in the gas channel (11) by at least one of the following methods: threaded pair, snap-fit, interference fit, welding or adhesive fixation.

5. A pressure-reducing entropy-variable gas flow meter according to claim 4, characterized in that: The in-hole sensor includes an in-hole pressure sensor (31) for acquiring the pressure of the compression chamber (111) and an in-hole temperature sensor (41) for acquiring the temperature of the compression chamber (111). The post-hole sensor includes a post-hole temperature sensor (42) for acquiring the temperature of the expansion chamber (112).

6. A pressure-reducing entropy-variable gas flow meter according to claim 5, characterized in that: The post-hole sensor also includes a post-hole pressure sensor (32) for acquiring the pressure of the expansion chamber (112).

7. A pressure-reducing entropy-variable gas flow meter according to claim 6, characterized in that: The main body (1) has a first mounting hole (12) communicating with the compression chamber (111) and a second mounting hole (13) communicating with the expansion chamber (112) respectively on its pipe wall. The pressure sensor (31) before the hole and the temperature sensor (41) before the hole are fixedly installed at the first mounting hole (12), and the pressure sensor (32) after the hole and the temperature sensor (42) after the hole are fixedly installed at the second mounting hole (13) and the second mounting hole (13) is closed.

8. A pressure-reducing entropy-variable gas flow meter according to claim 7, characterized in that: The collecting end of the pre-hole temperature sensor (41) extends into the flow channel of the compression chamber (111), and the collecting end of the post-hole temperature sensor (42) extends into the flow channel of the expansion chamber (112); the collecting end of the pre-hole pressure sensor (31) does not extend into the flow channel of the compression chamber (111) but is only connected to the flow channel of the compression chamber (111), and the collecting end of the post-hole pressure sensor (32) does not extend into the flow channel of the expansion chamber (112) but is only connected to the flow channel of the expansion chamber (112).

9. A pressure-reducing entropy-variable gas flow meter according to claim 7, characterized in that: The acquisition ends of the in-hole pressure sensor (31) and the in-hole temperature sensor (41) are both inserted into the flow channel of the compression chamber (111), and the acquisition ends of the in-hole pressure sensor (32) and the in-hole temperature sensor (42) are both inserted into the flow channel of the expansion chamber (112).

10. A pressure-reducing entropy-variable gas flow meter according to any one of claims 1-9, characterized in that: The pressure-reducing entropy variable gas flow meter also includes an atmospheric pressure sensor and an atmospheric temperature sensor. The acquisition ends of the atmospheric pressure sensor and the atmospheric temperature sensor are directly exposed to the external natural ambient air. The data from the atmospheric pressure sensor and the atmospheric temperature sensor are transmitted to the control center (6). The air inlet (14) and air outlet (15) of the body (1) are both equipped with quick-connect interfaces (5), and an air inlet pressure sensor (30) is installed at the air inlet (14).

11. A flow controller based on a pressure-reducing entropy-variable gas flow meter according to any one of claims 1-10, characterized in that: The gas passage (11) has a control valve (7) installed at the front end of the compression chamber (111). The control center (6) controls the opening of the control valve (7). The control center (6) adjusts the opening of the control valve (7) in real time according to the comparison between the calculated real-time flow and the target flow.

12. The flow controller according to claim 11, characterized in that: The control valve (7) is a proportional solenoid valve.

Images