阅读说明：本技术 气体质量流量控制方法及装置 (Gas mass flow control method and device ) 是由 杜井庆 王瑞 苏乾益 于 2021-08-31 设计创作，主要内容包括：本发明提供了一种气体质量流量控制方法及装置,包括：设定目标流量值；控制进气流量控制单元接通进气管路,同时控制出气流量控制单元断开出气管路,以使进气管路能够向流量控制腔室内输送气体,直至流量控制腔室的内部气体压力达到第一预设压力值；控制进气流量控制单元断开进气管路,同时控制出气流量控制单元接通出气管路；实时检测流量控制腔室的内部气体压力,并根据流量控制腔室的内部气体压力变化,实时计算流量控制腔室的当前出气流量值；控制出气流量控制单元调节流量控制腔室的当前内部气体压力,以使当前出气流量值等于目标流量值。本发明提出的气体质量流量控制方法及装置具有对信号响应快和调节速度快等优点。(The invention provides a method and a device for controlling gas mass flow, comprising the following steps: setting a target flow value; controlling the air inlet flow control unit to be connected with the air inlet pipeline, and simultaneously controlling the air outlet flow control unit to be disconnected with the air outlet pipeline, so that the air inlet pipeline can convey gas into the flow control chamber until the internal gas pressure of the flow control chamber reaches a first preset pressure value; controlling the air inlet flow control unit to disconnect the air inlet pipeline and controlling the air outlet flow control unit to connect the air outlet pipeline; detecting the internal gas pressure of the flow control chamber in real time, and calculating the current outlet flow value of the flow control chamber in real time according to the internal gas pressure change of the flow control chamber; and controlling the outlet flow control unit to adjust the current internal gas pressure of the flow control chamber so that the current outlet flow value is equal to the target flow value. The gas mass flow control method and the gas mass flow control device have the advantages of fast response to signals, fast adjustment speed and the like.)

1. A gas mass flow control method is applied to a gas mass flow control device and is characterized in that the gas mass flow control device comprises a flow control chamber, an air inlet pipeline and an air outlet pipeline which are respectively connected with an air inlet and an air outlet of the flow control chamber, and an air inlet flow control unit and an air outlet flow control unit which are respectively arranged on the air inlet pipeline and the air outlet pipeline;

the gas mass flow control method comprises the following steps:

setting a target flow value;

controlling the inlet flow control unit to switch on the inlet pipeline, and simultaneously controlling the outlet flow control unit to switch off the outlet pipeline, so that the inlet pipeline can convey gas into the flow control chamber until the internal gas pressure of the flow control chamber reaches a first preset pressure value;

controlling the air inlet flow control unit to disconnect the air inlet pipeline and simultaneously controlling the air outlet flow control unit to connect the air outlet pipeline;

detecting the internal gas pressure of the flow control chamber in real time, and calculating the current outlet flow value of the flow control chamber in real time according to the internal gas pressure change of the flow control chamber; controlling the outlet flow control unit to adjust the current internal gas pressure of the flow control chamber so that the current outlet flow value is equal to the target flow value.

2. The gas mass flow control method of claim 1, wherein the current outlet flow value is calculated according to a first formula, the first formula being:

wherein Q is the current outlet flow value; Δ t is a time period from a time when the internal gas pressure of the flow control chamber reaches the first preset pressure value to a current time; Δ m is the flow rateA value of mass change of gas in Δ t within the chamber; v is the volume of the flow control chamber; r is a universal gas constant; p₁The first preset pressure value is obtained; p₂Is the current internal gas pressure value; t is₁When the pressure of the flow control chamber reaches the first preset pressure value, the temperature of the gas in the flow control chamber is determined; t is₂The temperature of the flow control chamber gas at the current pressure; m is the molar mass of the gas in the flow control chamber.

3. The gas mass flow control method of claim 2, wherein the parameter in the first formula satisfies T₁＝T₂(ii) a The first formula is simplified into a second formula, and the second formula is as follows:

wherein T is a temperature of the gas in the flow control chamber, Δ P is a change value of an internal gas pressure of the flow control chamber, and T ═ T₁＝T₂，Q₂＝Q。

4. The gas mass flow control method of claim 1, further comprising:

detecting the internal gas pressure of the flow control chamber in real time, and judging whether the internal gas pressure of the flow control chamber is lower than a second preset pressure value, wherein the second preset pressure value is smaller than the first preset pressure value; if yes, controlling the air inlet flow control unit to be connected with the air inlet pipeline until the internal gas pressure of the flow control chamber reaches a first preset pressure value, and controlling the air inlet flow control unit to be disconnected with the air inlet pipeline.

5. The gas mass flow control method of claim 1, wherein said controlling the outlet flow control unit to adjust a current internal gas pressure of the flow control chamber to make the current outlet flow value equal to the target flow value comprises:

and controlling the outlet flow control unit by a PID control method based on the target flow value and the current outlet flow value obtained by calculation so as to enable the current outlet flow value to be equal to the target flow value.

6. A gas mass flow control device, comprising: the device comprises a temperature sensor, a pressure sensor, a flow control chamber, an air inlet pipeline and an air outlet pipeline which are respectively connected with an air inlet and an air outlet of the flow control chamber, and an air inlet flow control unit, an air outlet flow control unit and a control unit which are respectively arranged on the air inlet pipeline and the air outlet pipeline;

the temperature sensor and the pressure sensor are used for respectively detecting the temperature and the pressure in the flow control chamber in real time and sending the temperature and the pressure to the control unit;

the control unit is used for controlling the gas inlet flow control unit and the gas outlet flow control unit by adopting the gas mass flow control method of any one of claims 1 to 5 according to the temperature and the pressure of the gas in the flow control chamber detected by the temperature sensor and the pressure sensor in real time.

7. The gas mass flow control device of claim 6, wherein the intake flow control unit includes a first flow control valve provided on the intake line for turning on or off the intake line and adjusting the flow rate of the gas in the intake line; and/or the presence of a gas in the gas,

the air outlet flow control unit comprises a second flow control valve, and the second flow control valve is arranged on the air outlet pipeline and used for connecting or disconnecting the air outlet pipeline and adjusting the air flow in the air outlet pipeline.

8. The gas mass flow control device according to claim 6, wherein the intake flow control unit includes a first on-off valve and a first flow regulating valve, both of which are provided on the intake line, wherein the first on-off valve is used to turn on or off the intake line; the first flow regulating valve is used for regulating the gas flow in the gas inlet pipeline; and/or the presence of a gas in the gas,

the air outlet flow control unit comprises a second on-off valve and a second flow regulating valve, the second on-off valve and the second flow regulating valve are both arranged on the air outlet pipeline, and the second on-off valve is used for switching on or off the air outlet pipeline; and the second flow regulating valve is used for regulating the gas flow in the gas outlet pipeline.

9. The gas mass flow control device of claim 6, wherein the control unit is further configured to control the exchange of functions of the inlet flow control unit and the outlet flow control unit such that one is used for inlet and the other is used for exhaust.

10. A gas mass flow control device according to claim 6, wherein the flow control chamber has one or more interconnected flow control sub-cavities inside, the flow control sub-cavities being cylindrical and/or cubic.

Technical Field

The invention relates to the technical field of gas mass flow control, in particular to a gas mass flow control method and a gas mass flow control device.

Background

Mass Flow Controllers (MFCs) are used to precisely measure and control the Mass Flow of a gas. They have important applications in scientific research and production in various fields such as semiconductor and integrated circuit processes, special material disciplines, chemical industry, petroleum industry, medicine, environmental protection, vacuum and the like. Typical applications include processes in microelectronic processing equipment such as diffusion, oxidation, epitaxy, CVD, plasma etching, sputtering, ion implantation, etc. The related application equipment also comprises coating equipment, optical fiber smelting, a micro-reaction device, a gas mixing and distributing system, gas sampling, capillary measurement, a gas chromatograph, other analytical instruments and the like.

In conventional industrial applications and semiconductor devices, a thermal gas mass flow controller is often used to control the flow mass of a gas for a manufactured semiconductor component, and the flow detection principle of the thermal gas mass flow controller is thermal, that is, the flow of the gas is detected by detecting the change of the heat of the gas flowing through a temperature sensor, but the change of the temperature of the gas flowing through the temperature sensor is slow, so that the change of a detection signal of the thermal sensor is slow, and finally, the response time of the thermal gas mass flow controller is long, and the input and output of the gas flow cannot be controlled in time. In addition, the thermal gas mass flow controller has a series of problems of large temperature drift, pressure sensitivity and the like, so that the thermal gas mass flow controller cannot be used in microelectronic process equipment with strict control requirements, and further, some semiconductor components can only realize the preparation of the semiconductor components by increasing the process flow, thereby increasing the process cost and the process time.

Disclosure of Invention

The embodiment of the invention aims to solve at least one technical problem in the prior art, and provides a gas mass flow control method and a gas mass flow control device, which have the advantages of high signal response speed, high regulation speed and the like.

In order to solve one of the above problems, an embodiment of the present invention provides a gas mass flow control method applied to a gas mass flow control device, where the gas mass flow control device includes a flow control chamber, an inlet pipeline and an outlet pipeline connected to an inlet and an outlet of the flow control chamber, respectively, and an inlet flow control unit and an outlet flow control unit respectively disposed on the inlet pipeline and the outlet pipeline;

the gas mass flow control method comprises the following steps:

setting a target flow value;

controlling the inlet flow control unit to switch on the inlet pipeline, and simultaneously controlling the outlet flow control unit to switch off the outlet pipeline, so that the inlet pipeline can convey gas into the flow control chamber until the internal gas pressure of the flow control chamber reaches a first preset pressure value;

controlling the air inlet flow control unit to disconnect the air inlet pipeline and simultaneously controlling the air outlet flow control unit to connect the air outlet pipeline;

detecting the internal gas pressure of the flow control chamber in real time, and calculating the current outlet flow value of the flow control chamber in real time according to the internal gas pressure change of the flow control chamber; controlling the outlet flow control unit to adjust the current internal gas pressure of the flow control chamber so that the current outlet flow value is equal to the target flow value.

Optionally, the current outlet flow value is obtained by calculation according to a first formula, where the first formula is:

wherein Q is the current outlet flow value; Δ t is a time period from a time when the internal gas pressure of the flow control chamber reaches the first preset pressure value to a current time; Δ m is the value of the change in mass of the gas in Δ t within the flow control chamber; v is the volume of the flow control chamber; r is a universal gas constant; p₁The first preset pressure value is obtained;P₂is the current internal gas pressure value; t is₁When the pressure of the flow control chamber reaches the first preset pressure value, the temperature of the gas in the flow control chamber is determined; t is₂The temperature of the flow control chamber gas at the current pressure; m is the molar mass of the gas in the flow control chamber.

Optionally, the parameter in the first formula satisfies T₁＝T₂(ii) a The first formula is simplified into a second formula, and the second formula is as follows:

wherein T is a temperature of the gas in the flow control chamber, Δ P is a change value of an internal gas pressure of the flow control chamber, and T ═ T₁＝T₂，Q₂＝Q。

Optionally, the gas mass flow control method further comprises:

detecting the internal gas pressure of the flow control chamber in real time, and judging whether the internal gas pressure of the flow control chamber is lower than a second preset pressure value, wherein the second preset pressure value is smaller than the first preset pressure value; if yes, controlling the air inlet flow control unit to be connected with the air inlet pipeline until the internal gas pressure of the flow control chamber reaches a first preset pressure value, and controlling the air inlet flow control unit to be disconnected with the air inlet pipeline.

Optionally, the controlling the outlet flow control unit to adjust the current internal gas pressure of the flow control chamber so that the current outlet flow value is equal to the target flow value includes:

and controlling the outlet flow control unit by a PID control method based on the target flow value and the current outlet flow value obtained by calculation so as to enable the current outlet flow value to be equal to the target flow value.

As another technical solution, an embodiment of the present invention further provides a gas mass flow control device, including: the device comprises a temperature sensor, a pressure sensor, a flow control chamber, an air inlet pipeline and an air outlet pipeline which are respectively connected with an air inlet and an air outlet of the flow control chamber, and an air inlet flow control unit, an air outlet flow control unit and a control unit which are respectively arranged on the air inlet pipeline and the air outlet pipeline;

the temperature sensor and the pressure sensor are used for respectively detecting the temperature and the pressure in the flow control chamber in real time and sending the temperature and the pressure to the control unit;

the control unit is configured to control the inlet flow control unit and the outlet flow control unit by using the gas mass flow control method according to the temperature and the pressure of the gas in the flow control chamber detected by the temperature sensor and the pressure sensor in real time.

Optionally, the intake air flow control unit includes a first flow control valve, which is disposed on the intake pipe and is used for switching on or off the intake pipe and regulating the flow of gas in the intake pipe; and/or the presence of a gas in the gas,

the air outlet flow control unit comprises a second flow control valve, and the second flow control valve is arranged on the air outlet pipeline and used for connecting or disconnecting the air outlet pipeline and adjusting the air flow in the air outlet pipeline.

Optionally, the intake flow control unit includes a first on-off valve and a first flow regulating valve, and the first on-off valve and the first flow regulating valve are both disposed on the intake pipeline, wherein the first on-off valve is used for switching on or off the intake pipeline; the first flow regulating valve is used for regulating the gas flow in the gas inlet pipeline; and/or the presence of a gas in the gas,

the air outlet flow control unit comprises a second on-off valve and a second flow regulating valve, the second on-off valve and the second flow regulating valve are both arranged on the air outlet pipeline, and the second on-off valve is used for switching on or off the air outlet pipeline; and the second flow regulating valve is used for regulating the gas flow in the gas outlet pipeline.

Optionally, the control unit is further configured to control the functions of the intake flow control unit and the exhaust flow control unit to be interchanged, so that one is used for intake and the other is used for exhaust.

Optionally, the flow control chamber has one or more interconnected flow control sub-cavities inside, and the flow control sub-cavities are cylinders and/or cubes.

The embodiment of the invention has the following beneficial effects:

according to the gas mass flow control method provided by the embodiment of the invention, the current outlet flow value of the flow control chamber is calculated in real time by monitoring the pressure change in the flow control chamber in real time and according to the pressure change, and the current pressure in the flow control chamber is regulated by using the outlet flow control unit until the current outlet flow value of the flow control chamber reaches the target flow value; the gas mass flow control method and the gas mass flow control device provided by the embodiment of the invention can make quick response when the mass flow value in the gas outlet pipeline changes, so that the gas mass flow value in the gas outlet pipeline can be adjusted in time to reduce zero drift, further the adjustment precision of the gas mass flow control can be improved, and the precision of a process using the gas mass flow control device can be improved.

The gas mass flow control device provided by the embodiment of the invention is used for executing the gas mass flow control method in the embodiment, so that the gas mass flow control device can also make quick response when the mass flow value in the gas outlet pipeline changes, so that the gas mass flow value in the gas outlet pipeline can be timely adjusted, and the adjustment precision of the gas mass flow control can be improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention without limiting the invention in which:

FIG. 1 is a schematic diagram of a prior art thermal gas mass flow controller;

FIG. 2 is a flow chart of a gas mass flow control method provided in example 1 of the present invention;

fig. 3 is a schematic view of a gas mass flow rate control device according to embodiment 2 of the present invention.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

Fig. 1 is a schematic structural diagram of a conventional thermal gas mass flow controller, which includes a flow divider 01, a thermal sensor 02, a flow regulating valve 03, and a central processor 04; the thermal sensor 02 is configured to detect a gas temperature at a gas inlet side and a gas temperature at a gas outlet side of the flow divider 01, and send the detected gas temperature values to the central processor 04, so as to calculate a current mass flow of the gas according to a temperature variation of the gas, and thus adjust an opening degree of the flow adjusting valve 03 according to the current mass flow of the gas, so as to adjust the mass flow output by the gas to a process expected value. However, in actual production, since the temperature signal detected by the thermal sensor 01 changes slowly, when the thermal gas mass flow controller is used to control the mass flow of the gas, the response time for detecting the mass flow value of the gas is long, so that the change of the mass flow value of the gas cannot be detected in time, the mass flow value of the gas cannot be adjusted in time, and the process precision of the gas application is reduced.

Example 1

In order to solve one of the problems in the prior art, the present embodiment provides a gas mass flow control method, which is applied to a gas mass flow control device for controlling the mass of a gas passing through a section of a pipeline per unit time. Specifically, the gas mass flow rate control device includes: the flow control device comprises a flow control chamber, an air inlet pipeline and an air outlet pipeline which are respectively connected with an air inlet and an air outlet of the flow control chamber, and an air inlet flow control unit and an air outlet flow control unit which are respectively arranged on the air inlet pipeline and the air outlet pipeline.

As shown in fig. 2, the method for controlling gas mass flow provided by this embodiment includes the following steps:

step S1: setting a target flow value; specifically, the target flow rate value is a mass flow rate value of gas, that is, the mass of gas in a unit time when fluid passes through a pipeline section, and the target flow rate value can be set according to actual production needs;

step S2: controlling the air inlet flow control unit to be connected with the air inlet pipeline, and simultaneously controlling the air outlet flow control unit to be disconnected with the air outlet pipeline, so that the air inlet pipeline can convey gas into the flow control chamber until the pressure of the flow control chamber reaches a first preset pressure value;

step S3: after the pressure of the flow control chamber reaches a first preset pressure value, controlling the air inlet flow control unit to disconnect the air inlet pipeline;

step S4: calculating the current outlet flow value of the flow control chamber in real time according to the pressure change in the flow control chamber; and controlling the outlet flow control unit to adjust the current pressure in the flow control chamber so that the current outlet flow value is equal to the target flow value.

Specifically, the step S4 of "controlling the outlet flow rate control unit to adjust the current pressure in the flow control chamber" means that the current outlet flow rate is adjusted by adjusting the opening degree of the outlet flow rate control unit, where the larger the opening degree is, the larger the current outlet flow rate value is, and the smaller the opening degree is, the smaller the current outlet flow rate value is, and correspondingly, the larger the current outlet flow rate value is, the faster the current pressure in the flow control chamber is decreased, and the smaller the current outlet flow rate value is, the slower the current pressure in the flow control chamber is decreased, so that the current pressure in the flow control chamber can be adjusted by adjusting the opening degree of the outlet flow rate control unit; in other words, the current outlet flow rate value can be obtained by detecting the current pressure change in the flow control chamber.

The gas mass flow control method provided by this embodiment provides that the opening of the gas outlet flow control unit is adjusted according to the detection result while the gas pressure inside the flow control chamber is detected in real time, and the characteristic that the pressure detection element generally has a fast response speed to a pressure signal is utilized, especially the response speed to the change of a temperature signal is faster compared with the response speed of the existing thermal gas mass flow controller, so that the change of the pressure inside the flow control chamber can be detected in time; moreover, the calculation speed of the control unit can be further improved by calculating the current outlet flow value of the flow control chamber only according to the pressure change in the flow control chamber, namely, calculating only according to one variable of the flow control chamber; in addition, the gas mass flow rate is adjusted by directly adjusting the pressure of the flow control chamber, so that the influence of pressure fluctuation on the gas mass flow rate can be avoided.

In some embodiments, the step S4 includes, for example: controlling an outlet flow control unit by a PID control method based on the target flow value and the current outlet flow value obtained by calculation so as to enable the current outlet flow value to be equal to the target flow value; the PID control method is a control algorithm integrating three links of proportion, integration and differentiation, and has the advantages of high response speed, small oscillation and the like, so that the corresponding speed of the gas mass flow control device on the change of the gas mass flow can be further improved, and corresponding adjustment actions can be rapidly made.

In some embodiments, the current outlet flow value may be obtained by calculating according to a first formula, specifically, the first formula is:

wherein Q is the current outlet flow value; delta t is the time from the moment when the internal gas pressure of the flow control chamber reaches the first preset pressure value to the current moment; Δ m is the value of the change in mass of the gas in Δ t within the flow control chamber; v is the volume of the flow control chamber, and specifically, since the flow control chamber is generally a rigid body, the value of V is a fixed value; r is a general gas constant, also known as an "ideal gas constant"Specifically, the R value is independent of the gas species and is generally equal to about 8.314 J.mol^-1·K^-1；P₁Is a first preset pressure value; p₂The current internal gas pressure value; t is₁Controlling the temperature of the chamber gas at a first preset pressure value; t is₂Controlling the temperature of the chamber gas at the current pressure; m is a molar mass of the gas in the flow control chamber, specifically, a mass of a substance having a molar mass per amount of the substance, which is determined by the kind of the gas. As can be seen from the above, in the first formula, V, R, P₁And the value of M is known, so only T needs to be detected₁、T₂And P₂The preset flow rate value Q can be obtained according to the first formula. In other words, it can be inferred from the first formula that the pressure value P at the present moment is adjusted₁The flow rate value (Q) of the output gas can be adjusted.

Specifically, the parameter Δ m in the first formula satisfies the following relationship:

Δm＝m₁-m₂，

wherein m is₁When the pressure of the flow control chamber is a first preset pressure value, controlling the mass of the gas in the flow control chamber; m is₂The flow control chamber pressure is the mass of gas in the flow control chamber at the current time. And according to an ideal gas state equation, the following can be deduced:

from this, the following relationship can be derived by the reduction operation:

in some embodiments, the time (Δ t) if the gas flows out) Very short, there is little change in the gas temperature inside the flow control chamber, i.e., the parameter T in the first equation above₁＝T₂Then, the first formula can be reduced to a second formula, specifically, the second formula is:

where T is the temperature of the gas in the flow control chamber, Δ P is the change in gas pressure inside the flow control chamber, and T ═ T₁＝T₂Therefore, Q can be obtained from the third formula₂Q. It can be seen that, when the gas outflow time (Δ t) is short, the actual output gas flow rate value (Q) obtained by the gas mass flow rate control method provided in this example is used₂) The preset flow value can be infinitely approached. Furthermore, from the above, the plurality of parameters in the second formula: the volume (V) of the flow control chamber, the molar mass (M) of the gas, and the universal gas constant (R) are known, and the temperature (T) of the gas in the flow control chamber is typically measured in advance and hardly changes in actual production, so the second equation can be further simplified as:

where K is VM/RT, that is, K is a coefficient relating to only V, M, R, T, which can be measured before the gas mass flow control flow starts, so that the amount of calculation by the control unit can be further reduced, thereby further improving the response speed of the control unit.

In some embodiments, the gas mass flow control method further comprises the steps of:

detecting the internal gas pressure of the flow control chamber in real time, and judging whether the internal gas pressure of the flow control chamber is lower than a second preset pressure value or not, wherein the second preset pressure value is smaller than the first preset pressure value;

if so, controlling the air inlet flow control unit to be connected with the air inlet pipeline until the internal gas pressure of the flow control chamber reaches a first preset pressure value, and controlling the air inlet flow control unit to be disconnected with the air inlet pipeline; namely, when the internal gas pressure of the flow control chamber is reduced to a second preset pressure, the gas inlet pipeline is communicated again to enable the gas inlet pipeline to be raised to the first preset pressure, so that the situation that the internal gas pressure value of the flow control chamber is too low, and the current outlet flow value cannot reach the target flow value no matter how large the opening degree of the outlet flow control unit is, is avoided;

note that, in order to ensure the continuous output of the gas, the gas outlet pipeline is kept connected while the step is carried out, and the gas outlet flow control unit continuously adjusts the current pressure in the flow control chamber so as to keep the current gas outlet flow value at the target flow value;

if not, the process continues to step S4.

In the method for controlling gas mass flow provided by this embodiment, the pressure change in the flow control chamber is monitored in real time, the current outlet flow value of the flow control chamber is calculated in real time according to the pressure change, and the current pressure inside the flow control chamber is adjusted by using the outlet flow control unit until the current outlet flow value of the flow control chamber reaches the target flow value; the gas mass flow control method and the gas mass flow control device provided by the embodiment of the invention can make quick response when the mass flow value in the gas outlet pipeline changes, so that the gas mass flow value in the gas outlet pipeline can be adjusted in time to reduce zero drift, further the adjustment precision of the gas mass flow control can be improved, and the precision of a process using the gas mass flow control device can be improved.

Example 2

Referring to fig. 3, the present embodiment provides a gas mass flow control device, which includes: the device comprises a temperature sensor 2, a pressure sensor 3, a flow control chamber 1, an air inlet pipeline 11 and an air outlet pipeline 12 which are respectively connected with an air inlet and an air outlet of the flow control chamber 1, an air inlet flow control unit 4 and an air outlet flow control unit 5 which are respectively arranged on the air inlet pipeline 11 and the air outlet pipeline 12, and a control unit 6.

The temperature sensor 2 and the pressure sensor 3 are used for detecting the temperature and the pressure in the flow control chamber 1 in real time, respectively, and sending the detected values to the control unit 6.

The control unit 6 is configured to control the inlet flow control unit 4 and the outlet flow control unit 5 by using the gas mass flow control method described in the above embodiment 1 according to the temperature and pressure of the gas in the flow control chamber 1 detected by the temperature sensor 2 and the pressure sensor 3 in real time.

The present embodiment provides a gas mass flow control apparatus for performing the gas mass flow control method described in embodiment 1. Specifically, the gas flows into the flow control chamber 1 through the gas inlet pipeline 11 connected to the gas inlet of the flow control chamber 1, and then flows out of the flow control chamber 1 through the gas outlet pipeline 12 connected to the gas outlet of the flow control chamber 1. However, the present embodiment is not limited thereto, and the gas may also flow into the flow control chamber 1 through the gas outlet pipeline 12 connected to the gas outlet of the flow control chamber 1, and then flow out of the flow control chamber 1 through the gas inlet pipeline 11 connected to the gas inlet of the flow control chamber 1, that is, the gas mass flow control device provided in the present embodiment may not only feed gas in the forward direction, but also feed gas in the reverse direction, which can facilitate the installation of the gas mass flow control device in the actual production. Furthermore, in some embodiments, the control unit is also used to control the exchange of functions of the inlet flow control unit and the outlet flow control unit such that one is used for inlet air and the other is used for exhaust air, thereby changing the direction of the gas flow in the case where the gas mass flow control device is already installed.

In some embodiments, the temperature sensor 2 and the pressure sensor 3 may also be integrated and disposed in the flow control chamber 1.

In some embodiments, the intake air flow control unit 4 includes a first flow control valve provided on the intake pipe 11 for turning on or off the intake pipe 11 and adjusting the flow rate of gas in the intake pipe 11. Alternatively, in some other embodiments, the intake air flow control unit 4 includes a first on-off valve and a first flow regulating valve, both of which are disposed on the intake pipe 11, wherein the first on-off valve is used to turn on or off the intake pipe 11; the first flow regulating valve is used to regulate the flow of gas in the inlet line 11.

In some embodiments, the outlet flow control unit 5 comprises a second flow control valve disposed on the outlet line 12 for switching the outlet line 12 on or off and regulating the flow of gas in the outlet line 12. Or, in some other embodiments, the outlet flow control unit 5 includes a second on-off valve and a second flow regulating valve, both of which are disposed on the outlet pipeline 12, wherein the second on-off valve is used to turn on or off the outlet pipeline 12; the second flow regulating valve is used for regulating the flow of the gas in the gas outlet line 12.

In some embodiments, the valves disposed on the inlet line 11 and the outlet line 12 may be solenoid valves or piezoelectric valves.

In some embodiments, the flow control chamber 1 has one or more interconnected flow control subchambers inside, wherein the flow control subchambers are cylinders and/or cubes.

The gas mass flow control device provided by this embodiment is used for executing the gas mass flow control method described in the above embodiment, so that it can also make a quick response when the mass flow value in the gas outlet pipeline changes, so as to adjust the gas mass flow value in the gas outlet pipeline in time, thereby improving the adjustment accuracy of the gas mass flow control.

It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.