Gas flow measuring system of high-speed metering valve

Abstract

The utility model relates to the technical field of high-speed metering valve gas flow measurement, and particularly discloses a high-speed metering valve gas flow measurement system which comprises a gas transmission gas tank and a controller, a gas inlet of the gas transmission gas tank is communicated with a gas supplementing pipe, and a first gas valve is arranged on the gas supplementing pipe; a gas outlet of the gas conveying gas tank is communicated with a gas conveying pipe; a second air valve, a first pressure sensor, a flow meter and an ejector are arranged on the air conveying pipe; the gas conveying pipe between the gas conveying gas tank and the second gas valve is connected with a dynamic compensation gas circuit through a tee joint; the dynamic compensation gas circuit comprises a circulating gas tank, a gas pump, a pressure stabilizing gas chamber and a regulating gas valve; the high-speed metering valve can meet the requirements of large flow, constant system pressure and the like in the gas flow measurement process, and is good in control effect and reliability.

Description

Technical Field

[0001] The utility model relates to the technical field of high-speed metering valve gas flow measurement, in particular to a high-speed metering valve gas flow measurement system. Background Art

[0002] For high-speed electromagnetic metering valves for gases such as LNG, CNG, LPG, and hydrogen metering valves, the supporting test or production equipment needs to perform precise measurements under constant gas pressure and sufficiently large flow. The conventional method is to use a gas proportional valve to adjust the pressure and then measure the flow of the injector pipeline. However, under large flow loading, the pressure control of the entire metering process is not stable enough, especially at the beginning of measurement in each flow section, the outlet pressure has a significant loss, which in turn affects the high-precision measurement results; therefore, it is necessary to design a measurement system for large-flow, high-precision gas pressure source measurement systems. Utility Model Content

[0003] In view of the above shortcomings, the utility model provides a high-speed metering valve gas flow measurement system, which can maintain the measurement system to continuously supply a large flow of gas and the stability of the gas pressure when measuring each flow section. In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0004] A high-speed metering valve gas flow measurement system comprises a gas tank and a controller, wherein the gas inlet of the gas tank is connected to an air supply pipe, on which a first gas valve is arranged; the gas outlet of the gas tank is connected to a gas pipe; the gas pipe is provided with a second gas valve, a first pressure sensor, a flow meter and an injector; the gas pipe between the gas tank and the second gas valve is connected to a dynamic compensation gas circuit via a tee, and the dynamic compensation gas circuit realizes automatic adjustment of the fluctuating gas pressure in the gas pipe by providing a pressure differential valve in the connection section with the gas pipe.

[0005] Optionally, the first air valve is an electrically controlled needle valve, and the electrically controlled needle valve includes a servo linear motor and a valve core; the valve core is set to a two-stage taper structure; the servo linear motor is used to control the opening and closing of the valve core. Optionally, the dynamic compensation gas circuit includes a circulating gas tank, an air pump, a pressure-stabilizing air chamber, and a regulating gas valve; the air outlet of the circulating gas tank is connected to the air inlet of the air pump; the air outlet of the air pump is connected to the air inlet of the pressure-stabilizing air chamber; the pressure-stabilizing air chamber is connected to the air inlet of the circulating gas tank through a circulating pipe; the regulating gas valve is arranged on the circulating pipe; the pressure-stabilizing air chamber is connected to the gas supply pipe through a compensation pipe; a pressure differential valve is arranged on the compensation pipe; the air inlet of the circulating gas tank is also connected to a second air supply pipe, and a third air valve is arranged on the second air supply pipe.

[0006] Optionally, the first gas valve is an electrically controlled needle valve, which includes a servo linear motor and a valve core; the valve core is configured as a two-stage taper structure; the servo linear motor is used to control the opening and closing of the valve core. Optionally, the gas transmission tank is provided with a second pressure sensor and a first overflow valve.

[0007] Optionally, a third pressure sensor and a second overflow valve are provided on the circulating gas tank.

[0008] Optionally, a fourth pressure sensor is provided on the pressure stabilizing air chamber.

[0009] Optionally, the air pressure in the pressure-stabilizing air chamber is not lower than the standard working air pressure on the air pipeline.

[0010] Compared with the prior art, the beneficial effects of the utility model are:

[0011] The utility model monitors and feeds back the working air pressure in time through the first pressure sensor at the front end of the air pipe, thereby improving the accuracy of controlling the actual ejection air pressure; and by arranging the dynamic compensation air circuit at the front end of the air pipe, the air pressure at the front end of the air pipe can be timely and efficiently regulated through the pressure-stabilizing air chamber and the pressure differential valve, thereby significantly improving the stability of the actual ejection air pressure; and by replenishing the gas in the air tank through the air replenishing pipe, the air pressure of the entire system is further maintained stable, thereby meeting the requirements of large flow and system constant pressure in the gas flow measurement process of the high-speed metering valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for describing the embodiments are briefly introduced below.

[0013] Figure 1 It is a schematic diagram of the mechanism of the utility model;

[0014] Figure 2 It is a cross-sectional view of the electric-controlled needle valve of the utility model. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0016] In the description of the present utility model, it should be noted that the directions or positional relationships indicated by the terms "inside", "front", "back", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the utility model product is usually placed when in use. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present utility model.

[0017] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] High-speed metering valve gas flow measurement system, such as Figure 1 As shown, it includes a gas tank 1 and a controller 4, and the gas outlet of the gas tank 1 is connected to a gas pipe; the gas pipe is provided with a second gas valve 6, a first pressure sensor 5, a flow meter 7 and an injector 8, and the second gas valve 6 adopts a solenoid valve. The gas tank 1 is provided with a second pressure sensor 2 and a first overflow valve 3, and the first overflow valve 3 is provided to prevent the gas pressure in the gas tank 1 from being too high. The gas inlet of the gas tank 1 is connected to an air supply pipe (the air pressure is not lower than the standard air pressure of the gas tank 1), and the air supply pipe is provided with a first gas valve. The advantage of this design is that when the first gas valve is opened for air supply, the gas tank 1 can play a certain buffering role on the front-end output airflow; in this embodiment, as Figure 2 As shown, the first gas valve is an electrically controlled needle valve 18, which includes a servo linear motor 22, a valve core 20, a valve body 19, and a valve seat 21; the valve core 20 is configured as a two-stage taper structure; the two-stage taper structure of the valve core 20 can achieve leak-free closing and linear opening, and when closed, the large-angle cone fits with the valve seat to ensure tight closing without causing deformation of the valve seat, and the small cone is used within the formation range of the servo linear motor. The equivalent opening of the valve is well linear, which is beneficial to the control of the control system; the servo linear motor 22 is used to control the opening and closing of the valve core, and the servo-driven valve core 20 has a fast response speed. Figure 1As shown by the dotted line, the second gas valve 6, the first pressure sensor 5, the flow meter 7, the second pressure sensor 2, etc. are all electrically connected to the controller 4; with the above structure, in actual control, for example, before starting the flow measurement at the front end of the gas pipe, the controller can increase the opening of the electric control needle valve in advance to ensure that the pressure loss at the moment of injection opening is smaller. The second pressure sensor 2 monitors the pressure in the gas tank 1 and feeds back the signal to the controller 4, and then issues a control instruction to the electric control needle valve 18;

[0019] In order to compensate for the lag in the compensation of the air pressure change in the above-mentioned air path structure and to improve the stability of the air pressure when the front end is exhausted with a large flow rate, in this embodiment, the air delivery pipe between the air delivery tank 1 and the second air valve 6 is connected with a dynamic compensation air path through a tee;

[0020] The dynamic compensation gas circuit includes a circulating gas tank 16, an air pump 10, a pressure-stabilizing gas chamber 11, and a regulating gas valve 9; once the previous systems are well regulated, during the use of the entire system, the airflow of the circulating gas tank 16, the air pump 10, the pressure-stabilizing gas chamber 11, the regulating gas valve 9, and the circulating gas tank 16 in the dynamic compensation gas circuit is in a continuous airflow cycle. If the air pressure on the gas pipeline is unstable (such as a drop in air pressure), the opening of the regulating gas valve 9 or the power of the air pump 10 is adjusted to maintain the stability of the air pressure in the pressure-stabilizing gas chamber 11. For example, in some embodiments, the selected pressure differential valve 13 is 1:1, and the air pressure in the pressure-stabilizing gas chamber 11 should generally be controlled to be equal to the air pressure of the gas pipeline. The standard working air pressure of the pipe; the pressure-stabilizing air chamber 11 is an air chamber with an inner cavity, which plays the role of air pressure compensation or high-pressure buffering for the gas pipeline; in this embodiment, the air pump 10 can be a variable frequency air pump or a fixed frequency air pump. When selecting, it is selected according to the air pressure control method of the dynamic compensation air circuit for the pressure-stabilizing air chamber 11. For example: if the air pressure of the pressure-stabilizing air chamber 11 is adjusted by adjusting the opening of the regulating air valve 9 to adjust the timely air pressure on the gas pipeline to be equal to the standard working air pressure, a fixed frequency air pump can be selected, that is, only an air pump of suitable power is selected during preparation. During operation, the air pump runs at rated power, that is, the flow rate / pump pressure of the air pump is relatively constant. However, if the air pressure of the pressure-stabilizing air chamber 11 is regulated by adjusting the flow rate / pump pressure of the air pump, a variable frequency air pump can be selected. At this time, the signal interface of the variable frequency air pump is electrically connected to the controller 4.

[0021] The air outlet of the circulating gas tank 16 is communicated with the air inlet of the air pump 10; the air outlet of the air pump 10 is communicated with the air inlet of the pressure-stabilizing air chamber 11; the pressure-stabilizing air chamber 11 is communicated with the air inlet of the circulating gas tank 16 through a circulating pipe; the regulating air valve 9 is arranged on the circulating pipe; the other air outlet of the pressure-stabilizing air chamber 11 is communicated with the air supply pipe through a compensating pipe; the pressure differential valve 13 is arranged on the compensating pipe; the purpose of the pressure differential valve 13 is that under normal circumstances, it is only necessary to maintain the air pressure of the pressure-stabilizing air chamber 11 within a set range (according to the standard working air pressure on the air supply pipe). Setting), once the air pressure in the gas pipeline is lower than the standard working air pressure, there is no need to control the monitoring, analysis and command control of the relevant electronic components in the control system, and the air pressure compensation of the gas pipeline can be carried out in a timely and effective manner; in some embodiments, in order to reduce the impact of the dynamic compensation air pressure on the measured air pressure in the gas pipeline, a one-way valve (not shown) can be provided at the pressure differential valve 13; the advantage of not providing a one-way valve is that when the first air valve performs air pressure compensation on the gas tank 1, if there is an excessive pressure fluctuation, the excessive pressure in the gas pipeline can be absorbed by the pressure-stabilizing air chamber 11.

[0022] During the normal airflow circulation process of the dynamic compensation air circuit (i.e., no air pressure compensation for the air pipe occurs), the air pressure in the pressure-stabilizing air chamber 11 must be maintained not lower than the standard working air pressure on the air pipe. Only in this way, when the air pressure in the air pipe is lower than the standard working air pressure, can the dynamic compensation air circuit provide timely and effective air pressure compensation for the air pipe.

[0023] The air inlet of the circulating gas tank 16 is also connected to a second air supply pipe, on which a third air valve 17 is provided. Its function is to replenish the circulating gas tank 16 with gas after the pressure stabilizing gas chamber 11 compensates the gas pipeline, and the replenishment is regulated by the following scheme:

[0024] The circulating gas tank 16 is provided with a third pressure sensor 15 and a second overflow valve 14 (both connected to the controller 4 ). The pressure stabilizing gas chamber 11 is provided with a fourth pressure sensor 12 . The fourth pressure sensor 12 can also be electrically connected to the controller, and is used to monitor the air pressure of the pressure-stabilizing air chamber 11. When in use, its main function is to debug the air pressure in the dynamic compensation air circuit during the early installation; before being put into use, it is necessary to adjust it in combination with the standard working air pressure on the gas pipeline. For example, if the power / flow / pump pressure of the air pump 10 and the opening of the regulating air valve 9 have been adjusted, then when the air pressure of the circulating gas tank 16 is P2, the air pressure of the pressure-stabilizing air chamber 11 can be just maintained at P1. The second overflow valve 14 is selected to maintain the air pressure of the circulating gas tank 16 not higher than P2. Once the third pressure sensor 15 detects that the air pressure of the circulating gas tank 16 reaches P1, it will provide signal feedback and close the third air valve 17 through the controller 4; and the opening of the third air valve 17 is controlled to replenish the circulating gas tank 16 with gas.

[0025] In this embodiment, when the system is operating normally, the air pump 10 and the regulating air valve 9 operate according to the set parameters, and the airflow of the circulating air tank 16, the air pump 10, the pressure-stabilizing air chamber 11, the regulating air valve 9, and the circulating air tank 16 in the dynamic compensation air circuit is in a continuous airflow cycle. The continuous cycle is conducive to timely air pressure compensation and improves the reliability of regulation. If the air pressure in the air pipeline drops due to the measurement of the jet and is lower than the standard working air pressure, the air pressure in the pressure-stabilizing air chamber 11 is not lower than the standard working air pressure, so the pressure differential valve 13 is opened. The pressure in the gas pipeline is opened, and the pressure stabilizing air chamber 11 compensates the air pressure in the gas pipeline. At this time (during the period of stabilizing and regulating the air pressure in the gas pipeline), the air pressure signal monitored by the first pressure sensor 5 on the gas pipeline is preferentially used to regulate the air pressure in the pressure stabilizing air chamber 11 (because the purpose of regulation is to maintain the air pressure in the gas pipeline stable within the standard working air pressure range). Therefore, at this time, the regulation of the air pump 10 or the regulating air valve 9 is also regulated based on the air pressure value of the first pressure sensor 5. For example, by increasing the power of the air pump 10 and / or reducing the opening of the regulating air valve 9, Increasing the air pressure in the pressure-stabilizing air chamber 11, reducing the power of the air pump 10 and / or increasing the opening of the regulating air valve 9 can reduce the air pressure in the pressure-stabilizing air chamber 11; the regulation of the air pump 10 and the regulating air valve 9 is preferably stepless regulation, and can be estimated and stepless regulation can be performed according to the air pressure linear value of the first pressure sensor 5 to ensure that the air pressure in the gas pipeline stabilizes quickly. After the air pressure in the gas pipeline stabilizes, the regulation is performed as follows: With the circulation of the air flow in the dynamic compensation air path, the air pressure in the pressure-stabilizing air chamber 11 tends to the set value, and because of the compensation of the gas supply to the gas pipeline, Therefore, the air pressure in the circulating gas tank 16 will be relatively reduced. At this time, the third air valve 17 is opened to replenish the circulating gas tank 16. At this time, the air pressure of the fourth pressure sensor 12 is maintained at the set value to quickly adjust the power of the air pump 10 and / or the opening of the regulating air valve 9. Finally, after the fourth pressure sensor 12 and the third pressure sensor 15, the air pump 10, and the regulating air valve 9 all reach the set value, the third air valve 17 is closed. In practice, the selected second overflow valve 14 also limits the maximum air pressure of the circulating gas tank 16. Finally, the dynamic compensation gas circuit completes the pressure compensation of the gas pipeline and its own internal circulation standard regulation, waiting to repeat the next pressure compensation operation.

[0026] The utility model provides an air replenishment pipe at the rear end of the air transmission tank 1, and realizes continuous gas replenishment through the electric-controlled needle valve 18, so as to meet the demand for large-flow air flow output and maintain the stable air pressure of the system. At the same time, the dynamic compensation air circuit is also cooperatively provided at the front end of the air transmission tank 1 to quickly and cooperatively compensate or absorb the air pressure at the front end of the air transmission pipe, which significantly improves the stability of the gas pressure of the measurement system during the large-flow gas injection measurement process, improves the measurement accuracy, and has a good use effect.

[0027] The method for controlling a gas flow measurement system using the utility model comprises:

[0028] (1) Relying on the first pressure sensor on the gas pipeline to timely monitor and feed back the dynamic gas pressure of the gas pipeline to the controller;

[0029] (2) maintaining the air circulation of the dynamic compensation air path through an air pump, and maintaining the air pressure of the pressure-stabilizing air chamber in dynamic balance, and the air pressure is not lower than the standard working air pressure on the air pipeline;

[0030] (3) Once the air pressure on the gas pipeline is lower than the standard working air pressure, the pressure differential valve on the compensation pipe is opened in time and the pressure stabilizing air chamber is used to quickly compensate the air pressure on the gas pipeline; at the same time, the air pressure of the pressure stabilizing air chamber is adjusted based on the timely air pressure monitored and fed back by the first pressure sensor, so as to adjust the timely air pressure on the gas pipeline to be equal to the standard working air pressure;

[0031] (4) The gas pressure of the gas transmission tank is compensated by adjusting the opening of the first gas valve.

[0032] Optionally, the step of adjusting the air pressure of the pressure-stabilizing air chamber involved in (3) adopts the following scheme: the air pressure of the pressure-stabilizing air chamber is adjusted by adjusting the opening of the regulating air valve to adjust the instantaneous air pressure on the air pipeline to be equal to the standard working air pressure.

[0033] Optionally, the step of adjusting the air pressure of the pressure-stabilizing air chamber involved in (3) adopts the following scheme: the air pressure of the pressure-stabilizing air chamber is adjusted by adjusting the flow rate / pump pressure of the air pump to regulate the real-time air pressure on the air pipe to be equal to the standard working air pressure.

Claims

1. High-speed metering valve gas flow measurement system, characterized by: It comprises a gas delivery tank and a controller, wherein the gas inlet of the gas delivery tank is connected with an air supply pipe, on which a first gas valve is arranged; the gas outlet of the gas delivery tank is connected with the gas delivery pipe; the gas delivery pipe is provided with a second gas valve, a first pressure sensor, a flow meter and an injector; the gas delivery pipe between the gas delivery tank and the second gas valve is connected with a dynamic compensation gas circuit via a tee, and the dynamic compensation gas circuit realizes automatic adjustment of the fluctuating gas pressure in the gas delivery pipe by providing a pressure difference valve in the connection section with the gas delivery pipe.

2. The high-speed metering valve gas flow measurement system according to claim 1, characterized in that: The first gas valve is an electrically controlled needle valve, which includes a servo linear motor and a valve core; the valve core is configured to have a two-stage taper structure; the servo linear motor is used to control the opening and closing of the valve core.

3. The high-speed metering valve gas flow measurement system according to claim 1, characterized in that: The dynamic compensation gas circuit includes a circulating gas tank, an air pump, a pressure-stabilizing air chamber, and a regulating gas valve; the gas outlet of the circulating gas tank is connected to the gas inlet of the air pump; the gas outlet of the air pump is connected to the gas inlet of the pressure-stabilizing air chamber; the pressure-stabilizing air chamber is connected to the gas inlet of the circulating gas tank through a circulating pipe; the regulating gas valve is arranged on the circulating pipe; the pressure-stabilizing air chamber is connected to the gas supply pipe through a compensation pipe; a pressure differential valve is arranged on the compensation pipe; the gas inlet of the circulating gas tank is also connected to a second gas compensation pipe, and a third gas valve is arranged on the second gas compensation pipe.

4. The high-speed metering valve gas flow measurement system according to claim 1, characterized in that: The first gas valve is an electrically controlled needle valve, which includes a servo linear motor and a valve core; the valve core is configured to have a two-stage taper structure; the servo linear motor is used to control the opening and closing of the valve core.

5. The high-speed metering valve gas flow measurement system according to claim 1, characterized in that: The gas transmission tank is provided with a second pressure sensor and a first overflow valve.

6. The high-speed metering valve gas flow measurement system according to claim 3, characterized in that: The circulating gas tank is provided with a third pressure sensor and a second overflow valve.

7. The high-speed metering valve gas flow measurement system according to claim 3, characterized in that: A fourth pressure sensor is arranged on the pressure stabilizing air chamber.

8. The high-speed metering valve gas flow measurement system according to claim 3, characterized in that: The air pressure of the pressure-stabilizing air chamber is not lower than the standard working air pressure on the air delivery pipe.

Images