A miniaturized wide-range high-precision gas supply system

Abstract

This invention discloses a miniaturized, wide-range, high-precision gas supply system, comprising a gas collection chamber (7) and a gas outlet chamber (16). The gas collection chamber (7) is connected to a high-pressure gas source through an input pipe and supplied with flow rate through a gas controller. The gas is then output to the gas outlet chamber (16) for buffering and rectification. The gas outlet chamber (16) outputs gas through an output pipe, on which a flow metering device is installed to measure the flow rate of the output gas. The gas controller of this invention has a simple structure, high technological maturity, and a large control range. It uses a critical flow Venturi nozzle for flow rate detection, making the overall structure of the supply device simple, low-cost, highly controllable, and able to meet the downstream requirements for a wide gas flow range, high precision, and rapid response.

Description

Technical Field

[0001] This invention relates to the field of gas supply technology, and in particular to a miniaturized, wide-range, high-precision gas supply system. Background Technology

[0002] The advantages of industrial gas supply systems lie in their high efficiency, flexibility, and reliability. Compared to traditional gas supply methods, industrial gas supply systems can be adjusted according to the needs of industrial equipment, thereby improving the accuracy and stability of gas supply. The system also enables automated control, reducing errors from manual intervention and improving production efficiency. Furthermore, industrial gas supply systems are flexible and can be customized to meet different industrial needs and production requirements.

[0003] Industrial gas supply systems come in a wide variety of types, and the gas supply requirements vary across different sectors. Gas supply systems have extensive applications in various fields. For example, in industries such as petrochemicals, metallurgy, and power generation, gas supply systems are widely used for gas supply and processing during production processes. In industries such as pharmaceuticals, bioengineering, and food processing, gas supply systems are used to control the composition and concentration of gases in the production environment, ensuring the stability and safety of the production process. In industries such as automotive and aerospace, gas supply systems are used to provide high-precision gas control and testing, guaranteeing product quality and safety.

[0004] With the development of industrial technology, the demand for industrial gas supply is becoming increasingly extreme and specific. In certain fields, such as aerospace and rail transportation, gas supply devices are required to achieve miniaturization, wide range, high precision, and fast response. The challenges lie in: 1) a wide range of gas supply pressure and flow rate; 2) high control precision; and 3) fast response speed. However, using traditional regulating valves and flow meters to achieve these functions has disadvantages such as high cost, complex process flow, and slow adjustment speed. Summary of the Invention

[0005] The purpose of this invention is to provide a miniaturized, wide-range, high-precision gas supply system to solve the technical problems of complex processes, low control accuracy, and slow response speed in existing gas supply devices.

[0006] The present invention is achieved by the following technical solution: a miniaturized wide-range high-precision gas supply system, including a gas collection chamber and a gas outlet chamber. The gas collection chamber is connected to a high-pressure gas source through an input pipe and the flow is supplied through a gas controller. The gas is then output to the gas outlet chamber for buffering and rectification. The gas outlet chamber outputs gas through an output pipe. A flow metering device is installed on the output pipe to measure the flow rate of the output gas.

[0007] Furthermore, the input pipeline is equipped with a first pressure gauge for displaying gas pressure, a filter for filtering gas, and a first manual ball valve and a first pneumatic ball valve for cutting off the gas path.

[0008] Furthermore, the gas collecting chamber is equipped with a first pressure transmitter for collecting gas pressure, a second pressure gauge for displaying gas pressure, a first vent valve for discharging gas, and a first drain valve for discharging impurities.

[0009] Furthermore, the gas controller includes multiple gas control units, each consisting of a gas supply pressure regulating throat and a solenoid valve connected in series.

[0010] Furthermore, the gas control unit comprises 16 groups.

[0011] Furthermore, the throat is made in the form of a critical flow standard nozzle.

[0012] Furthermore, the gas outlet chamber is equipped with a safety valve for monitoring gas pressure, a second drain valve for discharging impurities, and a vacuum pump. A manual shut-off valve for the vacuum pump is also provided between the vacuum pump and the gas outlet chamber.

[0013] Furthermore, the gas outlet chamber is also equipped with a second vent valve for discharging gas, a third pressure gauge for displaying gas pressure, a second pressure transmitter for collecting gas pressure, and a temperature sensor for collecting gas temperature.

[0014] Furthermore, the flow metering device employs a critical flow venturi nozzle, which is manufactured in the form of a circular throat critical flow venturi nozzle.

[0015] Furthermore, the output pipeline includes two parallel branches, one branch is equipped with a first critical flow Venturi nozzle and a second pneumatic ball valve, and the other branch is equipped with a second critical flow Venturi nozzle and a third pneumatic ball valve. A fourth pressure gauge for displaying gas pressure is also installed at the end of the output pipeline.

[0016] The beneficial effects of this invention are as follows: the gas controller of this invention has a simple structure, high technical maturity, and a large control range. It uses a critical flow Venturi nozzle for flow detection, which makes the overall structure of the supply device simple, low in cost, highly controllable, and able to meet the downstream requirements for a large gas flow range, high precision, and fast response. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the system of the present invention;

[0019] Figure 2 Create a schematic diagram of the larynx;

[0020] Figure 3 Schematic diagram of a critical flow Venturi nozzle;

[0021] In the diagram, 1-First pressure gauge, 2-Filter, 3-First manual ball valve, 4-First pneumatic ball valve, 5-First pressure transmitter, 6-Second pressure gauge, 7-Gas chamber, 8-First vent valve, 9-First drain valve, 10-Throat, 11-Solenoid valve, 12-Safety valve, 13-Second drain valve, 14-Vacuum pump manual shut-off valve, 15-Vacuum pump, 16-Outlet chamber, 17-Second vent valve, 18-Third pressure gauge, 19-Second pressure transmitter, 20-Temperature sensor, 21-First critical flow Venturi nozzle, 22-Second pneumatic ball valve, 23-Second critical flow Venturi nozzle, 24-Third pneumatic ball valve, 25-Fourth pressure gauge. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0023] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0024] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0025] Example 1

[0026] See Figure 1A miniaturized, wide-range, high-precision gas supply system includes a gas collection chamber 7 and a gas outlet chamber 16. The gas collection chamber 7 is connected to a high-pressure gas source via an input pipe and supplied with gas through a gas controller. The gas is then output to the gas outlet chamber 16 for buffering and rectification. The gas outlet chamber 16 outputs gas through an output pipe equipped with a flow metering device to measure the flow rate of the output gas. The input pipe is equipped with a first pressure gauge 1, a gas filter 2, and a first manual ball valve 3 and a first pneumatic ball valve 4 to cut off the gas path. The gas collection chamber 7 is equipped with a first pressure transmitter 5, a second pressure gauge 6, a first vent valve 8, and a first drain valve 9. The gas controller includes 16 gas control units. The gas control unit consists of a gas supply and pressure regulating throat 10 and a solenoid valve 11 connected in series. The outlet chamber 16 is equipped with a safety valve 12, a second drain valve 13, and a vacuum pump 15. A manual shut-off valve 14 for the vacuum pump is also provided between the vacuum pump 15 and the outlet chamber 16. The outlet chamber 16 is also equipped with a second vent valve 17, a third pressure gauge 18, a second pressure transmitter 19, and a temperature sensor 20. The output pipeline includes two parallel branches. One branch is equipped with a first critical flow Venturi nozzle 21 and a second pneumatic ball valve 22. The other branch is equipped with a second critical flow Venturi nozzle 23 and a third pneumatic ball valve 24. A fourth pressure gauge 25 is also provided at the end of the output pipeline.

[0027] It should be noted that the target control value of this invention can be either the pressure or the flow rate of the gas at the device outlet. The specific principle is as follows: High-pressure gas enters the gas collection chamber after passing through a front-end filter, a manual ball valve, and a pneumatic ball valve. A customized gas controller supplies the flow rate and adjusts the pressure in the outlet chamber. The gas enters the outlet chamber for buffering and rectification. Closed-loop control is performed based on the target pressure or target flow rate at the outlet, and critical flow Venturi nozzles with different ranges are selected for gas flow rate measurement.

[0028] The functions of the equipment used in this invention are as follows: the gas collecting chamber 7 is used to collect gas sources and provide the prerequisite for pressure regulation; the gas outlet chamber 16 is used to buffer and rectify the gas after it has been regulated by the gas controller; the pneumatic ball valves (including the first pneumatic ball valve 4, the second pneumatic ball valve 22, and the third pneumatic ball valve 24) are used for program-controlled gas path cutoff; the filter 2 is used to filter the gas; the manual ball valves (including the first manual ball valve 3) are used for manual gas path cutoff; the solenoid valves 11 (16 sets in total) are used for program-controlled selection of different critical flow standard nozzles for gas supply; the throat 10 (16 sets in total) adopts the critical flow standard nozzle form ( Figure 2 It is manufactured for gas supply pressure regulation; the critical flow venturi nozzle (including the first critical flow venturi nozzle 21 and the second critical flow venturi nozzle 22) is made in the form of a circular throat critical flow venturi nozzle. Figure 3The system includes: a gas flow meter; a safety valve 12 for monitoring gas pressure and automatically releasing pressure when the warning value is exceeded; a vent valve (first vent valve 8 and second vent valve 17) for programmed gas discharge; a vacuum pump 15 for creating a vacuum in the pipeline; a manual shut-off valve 14 for cutting off the connection between the vacuum pump 15 and the outlet chamber 16; pressure gauges (including first pressure gauge 1, second pressure gauge 6, third pressure gauge 18 and fourth pressure gauge 25) for on-site monitoring and display of gas pressure; pressure transmitters (including first pressure transmitter 5 and second pressure transmitter 19) for acquiring gas pressure; and a temperature sensor 20 for acquiring gas temperature.

[0029] Specifically, the gas controller consists of a 16-position throat 10 and a solenoid valve 11, wherein the throat adopts a critical flow standard nozzle form. Figure 2 Made for gas pressure regulation. Figure 2 In this context, P1 refers to the inlet pressure of the critical flow standard nozzle, and P2 refers to the outlet pressure. If the inlet pressure P1 and temperature of the critical flow standard nozzle are kept constant, and its outlet pressure P2 is gradually decreased, the gas flow rate through the nozzle will gradually increase. When the outlet pressure drops to the critical pressure, the flow rate through the nozzle will reach its maximum value, and the gas velocity will be the local speed of sound. Further decreasing the outlet pressure will not increase the flow rate through the nozzle, and the velocity will remain constant at the speed of sound. The pressure at which the flow velocity at the outlet of the critical flow standard nozzle reaches the speed of sound is called the critical pressure Pc, Pc / P1 is called the critical pressure ratio, and the flow rate through the nozzle is called the critical flow rate. Although there is a pressure loss after passing through the critical flow standard nozzle, its simple structure, easy manufacturing, and guaranteed machining accuracy ensure its reliability. Under the critical pressure ratio condition, the flow rate calculation formula is:

[0030] In the formula, m: flow rate (kg / s), c is a constant coefficient (different values ​​for different gases), and A is the minimum cross-sectional area of ​​the nozzle throat (m²). 2 P1 is the nozzle inlet pressure in Pa, and T is the total temperature at the nozzle inlet in K. When the critical pressure ratio is not met, the flow rate calculation formula is:

[0031] Where m: flow rate (Kg / s); Cqh: flow coefficient; P1: nozzle inlet pressure (Pa); P2: nozzle outlet pressure (Pa); Pcrh: maximum allowable back pressure ratio; A: throat cross-sectional area (m2); T: throat inlet gas temperature (K); K: isentropic exponent; R: gas constant.

[0032] The critical flow standard nozzle throat areas are arranged according to a binary rule. Different throats can be combined to create different throat areas. The range of combined throat areas is between the sum of all throat areas and the minimum throat area. The minimum resolution is the minimum throat area. Therefore, designing a sufficiently small throat area can solve the positioning accuracy problem, and designing a sufficient number of bits can solve the flow rate adjustment range problem. The gas controller has a total of 16 sets of critical flow standard nozzles, allocated according to 15 bits, with throat diameters of 0.175mm, 0.247mm, 0.35mm, 0.495mm, 0.700mm, 0.990mm, 1.400mm, 1.980mm, 2.800mm, 3.960mm, 5.600mm, 7.920mm, 11.200mm, 15.840mm, 15.840mm, and 15.840mm. The 15th throat consists of two critical flow standard nozzles with a throat area of ​​15.840mm. The total throat area of ​​the gas controller is 788.138 mm2. Without considering machining errors, its throat area resolution, i.e. control accuracy, is 1 / 32768 = 0.003%FS.

[0033] Specifically, the critical flow venturi nozzles (including the first critical flow venturi nozzle 21 and the second critical flow venturi nozzle 22) are configured as an annular throat critical flow venturi nozzle. Figure 3 It is manufactured for measuring gas flow rate. Figure 3 In the diagram, P1 refers to the inlet pressure of the critical flow Venturi nozzle, P2 refers to the outlet pressure of the critical flow Venturi nozzle, A* refers to the throat area of ​​the critical flow Venturi nozzle, and A2 is the outlet area of ​​the diffuser section of the critical flow Venturi nozzle.

[0034] Flow detection using a critical flow Venturi nozzle: For gas flow rates ranging from 0.5 g / s to 6.00 kg / s, the large flow range makes gas mass flow meters difficult to meet the requirements and prohibitively expensive. This device uses a critical flow Venturi nozzle for flow measurement, satisfying the measurement requirements while reducing device costs. Within the pressure range where the critical flow Venturi nozzle can measure the critical flow rate, the flow rate through the nozzle is independent of the downstream pressure. For a given critical flow Venturi nozzle, the maximum flow rate range it can achieve is typically limited to its inlet pressure range, which is greater than the inlet pressure required to reach the critical flow rate. For the critical flow Venturi nozzle structure, the correspondence between the maximum back pressure ratio P2 / P1 and the diffuser area ratio A2 / A* varies for different gases. With a fixed diffuser area ratio for the critical flow Venturi nozzle, when the outlet pressure and inlet pressure reach the maximum back pressure ratio, the nozzle throat velocity is the speed of sound, and the flow rate is uniquely determined by the inlet pressure, inlet temperature, and throat area. The flow rate calculation formula is:

[0035] Where: m: flow rate Kg / s; c is a constant coefficient, which varies for different gases; A is the minimum cross-sectional area of ​​the nozzle throat m2; P1 is the nozzle inlet pressure Pa; T is the total temperature at the nozzle inlet K.

[0036] The performance characteristics of this embodiment are as follows:

[0037] (1) Device dimensions: 4000mm×1500mm×1500mm (length×width×height);

[0038] (2) Pressure control range: 40kPa~8MPa (absolute pressure);

[0039] (3) Mass flow rate range: 0.5 g / s to 6.00 kg / s;

[0040] (4) Pressure control accuracy: ≤0.3%FS;

[0041] (5) Flow measurement accuracy: ≤0.3%;

[0042] (6) The stabilization time for each pressure step control is ≤15s.

[0043] The flow closed-loop control method of this invention is as follows:

[0044] First, a mathematical model is established to discretize the opening degree of the intake solenoid valve.

[0045] Subsequently, the mathematical model was revised using experimental data, and a PID closed-loop algorithm was added.

[0046] The PID closed-loop algorithm employs a master-backup control strategy, switching the control strategy when a "control dead zone" occurs during pressure control.

[0047] Finally, given that the instantaneous switching of the solenoid valve can cause gas pressure fluctuations, a pressure derivative time setting has been added to the PID control strategy to reduce pressure fluctuation interference.

[0048] Pressure derivative processing: Based on the latest data, shift backward and take two data points with an interval of "pressure derivative time". One is used as the initial value of the PID control parameter, and the other is used as the latest value.

[0049] The operation method of this invention is as follows:

[0050] a) If the target outlet pressure is less than the local atmospheric pressure, manually open the manual shut-off valve 14 of the vacuum pump and start the vacuum pump 15 to reduce the pressure in the gas collection chamber 7 to less than the target outlet pressure.

[0051] b) After completing the first step, turn off the vacuum pump 15 and close the manual shut-off valve 14 of the vacuum pump. If the target outlet pressure is greater than the local atmospheric pressure, start the operation directly from this step.

[0052] c) Open the first manual ball valve 3 and the first pneumatic ball valve 4.

[0053] d) Select the critical flow Venturi nozzle (first critical flow Venturi nozzle 21 or second critical flow Venturi nozzle 23) according to the system flow rate, that is, open the second pneumatic ball valve 22 or the third pneumatic ball valve 24.

[0054] e) Set a flow closed loop or a pressure closed loop, and the system will automatically adjust the gas controller, that is, open different throats 10 and solenoid valves 11 in combination.

[0055] f) After the gas supply is completed, the system first automatically closes the first pneumatic ball valve 4, the second pneumatic ball valve 22, and the third pneumatic ball valve 24 in sequence. Then, it closes all the solenoid valves 10 of the gas controller, and finally opens the first vent valve 8 and the second vent valve 17.

[0056] g) When the pressure in the gas collecting chamber 7 and the pressure in the gas venting chamber 16 drop to the local atmospheric pressure, the system automatically closes the first vent valve 8 and the second vent valve 17.

[0057] h) Finally, manually close the first manual ball valve 3.

[0058] Based on the above embodiments, the present invention has at least the following technical effects:

[0059] The gas controller of this invention has a simple structure, high technological maturity, and a large control range. It uses a critical flow Venturi nozzle for flow detection, which makes the overall structure of the supply device simple, low-cost, highly controllable, and able to meet the downstream requirements for a large gas flow range, high precision, and rapid response.

[0060] It should be noted that the terms "connection" and "setting" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "connection" or "setting" may explicitly or implicitly include one or more of that feature. Furthermore, the terms "connection" and "setting," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Moreover, for the foregoing embodiments, for the sake of simplicity, they are all described as a series of actions; however, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Secondly, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions involved are not necessarily essential to this application.

[0061] The above embodiments describe the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Modifications and variations made by those skilled in the art without departing from the spirit and scope of the invention should be within the protection scope of the appended claims.

Claims

1. A miniaturized, wide-range, high-precision gas supply system, characterized in that, It includes a gas collection chamber (7) and a gas outlet chamber (16). The gas collection chamber (7) is connected to a high-pressure gas source through an input pipe and is supplied with flow through a gas controller. It is then output to the gas outlet chamber (16) for buffering and rectification. The gas outlet chamber (16) outputs gas through an output pipe. A flow metering device is installed on the output pipe to measure the flow of the output gas. The input pipeline is equipped with a first pressure gauge (1) for displaying gas pressure, a filter (2) for filtering gas, a first manual ball valve (3) for cutting off the gas path, and a first pneumatic ball valve (4); the gas collection chamber (7) is equipped with a first pressure transmitter (5) for collecting gas pressure, a second pressure gauge (6) for displaying gas pressure, a first vent valve (8) for discharging gas, and a first drain valve (9) for discharging impurities; the gas controller includes multiple gas control units, which are composed of a gas supply and pressure regulating throat (10) and a solenoid valve (11) connected in series; The flow metering device uses a critical flow venturi nozzle, which is made in the form of a circular throat critical flow venturi nozzle. The output pipe includes two parallel branches, one of which is equipped with a first critical flow venturi nozzle (21) and a second pneumatic ball valve (22), and the other branch is equipped with a second critical flow venturi nozzle (23) and a third pneumatic ball valve (24). A fourth pressure gauge (25) for displaying gas pressure is also installed at the end of the output pipe. The throat (10) is made in the form of a critical flow standard nozzle. The throat area of ​​the critical flow standard nozzle is arranged according to a binary rule. Different throat areas are combined by different throats. The range of the combined throat area is between the sum of all throat areas and the minimum throat area. The minimum resolution is the minimum throat area. The flow rate calculation formula for the critical flow standard nozzle under critical pressure ratio conditions is as follows: ； In the formula, m: flow rate (kg / s), c is a constant coefficient (different values ​​for different gases), and A is the minimum cross-sectional area of ​​the nozzle throat (m²). 2 , Where Pa is the nozzle inlet pressure, and T is the total temperature at the nozzle inlet, K. When the critical pressure ratio is not met, the flow rate calculation formula is: ； In the formula, m: flow rate (kg / s); : Circulation coefficient; Nozzle inlet pressure (Pa); Nozzle outlet pressure (Pa); : Maximum permissible back pressure ratio; A: Throat cross-sectional area (m²) 2 T: Temperature of the gas at the throat inlet (K); K: Isentropic exponent; R: Gas constant.

2. The miniaturized wide-range high-precision gas supply system as described in claim 1, characterized in that, There are 16 gas control units in total.

3. The miniaturized wide-range high-precision gas supply system as described in claim 1, characterized in that, The gas outlet chamber (16) is equipped with a safety valve (12) for monitoring gas pressure, a second drain valve (13) for discharging impurities, and a vacuum pump (15). A manual shut-off valve (14) for the vacuum pump is also provided between the vacuum pump (15) and the gas outlet chamber (16).

4. The miniaturized wide-range high-precision gas supply system as described in claim 3, characterized in that, The gas outlet chamber (16) is also equipped with a second vent valve (17) for discharging gas, a third pressure gauge (18) for displaying gas pressure, a second pressure transmitter (19) for collecting gas pressure, and a temperature sensor (20) for collecting gas temperature.

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