Pressure control system, pressure control method, and storage medium

Abstract

The present application provides a kind of pressure control system, the convergence pressure of closed space being provided with fluid resistance is controlled at high speed by upstream valve side edge being provided in the upstream side of fluid resistance, pressure control system (100) is provided with fluid resistance (10d) on the flow passage (200) of constituting closed space, the pressure of closed space is controlled by controlling upstream valve (10b) being provided in the upstream side of fluid resistance (10d), it is equipped with: convergence pressure calculation unit (40), using the upstream side pressure (P1) and downstream side pressure (P2) of fluid resistance (10d) in flow passage (200), calculate the convergence pressure (P CONV ) of closed space in the case of upstream valve (10b) being completely closed;And valve control unit (30), the convergence pressure (P CONV ) calculated is compared with the specified target convergence pressure (P T_CONV ), according to the comparison result, upstream valve (10b) is completely closed.

Description

Technical Field

[0001] This invention relates to a pressure control system, a pressure control method, and a storage medium. Background Technology

[0002] Conventionally, as shown in Patent Document 1, a fluid control device can be considered in which an upstream valve is provided on the upstream side of the fluid resistance in the flow channel through which the fluid flows, and a downstream valve is provided on the downstream side of the fluid resistance. By controlling the upstream valve and the downstream valve, the flow rate of the fluid flowing through the flow channel can be controlled.

[0003] In this fluid control device, when the flow path is cut off, both the upstream and downstream valves are completely closed. However, if the pressure between the upstream and downstream valves (including the enclosed space containing fluid resistance) fluctuates with each flow control operation, flow control cannot be identified and initiated. Therefore, to ensure stable flow control initiation, it is preferable to set the pressure between the upstream and downstream valves (including the enclosed space containing fluid resistance) to a predetermined convergence pressure.

[0004] Therefore, in the past, after completely closing both the upstream and downstream valves, the upstream valve was opened to allow fluid to flow in, and the upstream valve was closed when the upstream pressure of the fluid resistance reached the specified target pressure.

[0005] However, in the configuration where the upstream valve is closed when the pressure upstream of the fluid resistance reaches the specified target pressure, the flow path of the fluid is blocked downstream of the fluid resistance, causing the pressure in the enclosed space, including the fluid resistance, to exceed the specified convergence pressure (see reference). Figure 4 (a)). Furthermore, if flow control begins when the specified convergence pressure is exceeded, the accuracy of the flow measurement deteriorates, resulting in poorer controllability of the flow control. Additionally, while it is possible to control the opening and closing of the upstream valve to ensure that the upstream pressure does not exceed the specified convergence pressure, doing so would prolong the time until the upstream pressure converges to the convergence pressure (see [reference]). Figure 4 (b)

[0006] Existing technical documents

[0007] Patent Document 1: Japanese Patent Publication No. 2004-280688 Summary of the Invention

[0008] Therefore, the present invention was made to solve the above-mentioned problems. The main objective of the present invention is to control the convergence pressure of a closed space with fluid resistance at high speed by suppressing overshoot at an upstream valve located on the upstream side of the fluid resistance.

[0009] That is, the pressure control system of the present invention has a fluid resistance provided in the flow channel constituting the closed space, and controls the pressure of the closed space by controlling an upstream valve provided on the upstream side of the fluid resistance. The pressure control system includes: a convergence pressure calculation unit that calculates the convergence pressure of the closed space when the upstream valve is completely closed using at least one of the upstream pressure and the downstream pressure of the fluid resistance in the flow channel; and a valve control unit that compares the calculated convergence pressure with a predetermined target convergence pressure, and completely closes the upstream valve according to the comparison result.

[0010] In such a pressure control system, the convergence pressure of the enclosed space is calculated using at least one of the upstream and downstream pressures of the fluid resistance, with the upstream valve fully closed. The calculated convergence pressure is compared with a predetermined target convergence pressure. Based on the comparison result, the upstream valve is fully closed. Therefore, the convergence pressure of the enclosed space can be controlled at high speed while suppressing overshoot. Here, the predetermined target convergence pressure is set based on the pressure at which the set flow rate can flow through the full scale (100%) immediately after the valve is opened and flow control begins.

[0011] Preferably, when the calculated convergence pressure is above the specified target convergence pressure, the valve control unit completely closes the upstream valve.

[0012] The pressure control system of the present invention may also include a downstream valve disposed on the flow channel downstream of the fluid resistance, thereby forming a closed space downstream of the fluid resistance by completely closing the downstream valve.

[0013] Preferably, in this configuration, the convergence pressure calculation unit calculates the convergence pressure using the upstream pressure of the fluid resistance, the downstream pressure of the fluid resistance, the flow channel volume between the fluid resistance and the upstream valve, and the flow channel volume between the fluid resistance and the downstream valve.

[0014] Preferably, the convergence pressure calculation unit calculates the convergence pressure using the following formula.

[0015] [Mathematical Expression 1]

[0016]

[0017] Among them, P CONV P1 is the upstream pressure of the fluid resistance, P2 is the downstream pressure of the fluid resistance, V1 is the flow channel volume between the fluid resistance and the upstream valve, and V2 is the flow channel volume between the fluid resistance and the downstream valve.

[0018] Furthermore, the pressure control system of the present invention can form a closed space on the downstream side of the fluid resistance by connecting a sealed container on the flow channel. The convergence pressure calculation unit calculates the convergence pressure using the upstream pressure of the fluid resistance, the downstream pressure of the fluid resistance, the flow channel volume between the fluid resistance and the upstream valve, and the volume of the flow channel and the sealed container on the downstream side of the fluid resistance.

[0019] Preferably, the convergence pressure calculation unit calculates the convergence pressure in real time using at least one of the upstream pressure and the downstream pressure of the fluid resistance in the flow channel.

[0020] Preferably, the convergence pressure calculation unit corrects for the time-dependent changes in the volume of the enclosed space or the flow channel and calculates the convergence pressure.

[0021] Preferably, a position sensor is provided on the upstream valve to detect the position of the valve body relative to the valve seat. Additionally, in the case of a configuration with a downstream valve, it is preferable to provide a position sensor on the downstream valve to detect the position of the valve body relative to the valve seat.

[0022] Furthermore, the pressure control method of the present invention includes a fluid resistance provided in the flow channel constituting the enclosed space, and controls the pressure of the enclosed space by controlling an upstream valve provided on the upstream side of the fluid resistance. The pressure control method includes: a convergence pressure calculation step, using at least one of the upstream pressure and downstream pressure of the fluid resistance in the flow channel to calculate the convergence pressure of the enclosed space when the upstream valve is completely closed; and a valve control step, comparing the calculated convergence pressure with a predetermined target convergence pressure, and completely closing the upstream valve based on the comparison result.

[0023] Furthermore, the storage medium of the present invention stores a pressure control program for a pressure control system. This pressure control system has a fluid resistance in a flow channel constituting a closed space. The pressure of the closed space is controlled by controlling an upstream valve located upstream of the fluid resistance. A computer executes the pressure control program to function as a convergence pressure calculation unit and a valve control unit. The convergence pressure calculation unit uses at least one of the upstream and downstream pressures of the fluid resistance in the flow channel to calculate the convergence pressure of the closed space when the upstream valve is completely closed. The valve control unit compares the calculated convergence pressure with a predetermined target convergence pressure and, based on the comparison result, completely closes the upstream valve.

[0024] According to the present invention described above, the convergence pressure of a closed space with fluid resistance can be controlled at high speed by suppressing overshoot at the upstream valve side located upstream of the fluid resistance. Attached Figure Description

[0025] Figure 1 This is a schematic diagram illustrating a fluid control device (pressure control system) according to one embodiment of the present invention.

[0026] Figure 2 This is a diagram illustrating the method for controlling convergence pressure in the same implementation.

[0027] Figure 3 This is a schematic diagram illustrating a modified embodiment of a fluid control device (pressure control system).

[0028] Figure 4 This is a diagram illustrating the previous methods for controlling convergence pressure.

[0029] Explanation of reference numerals in the attached figures

[0030] 100··· Fluid control device (pressure control system)

[0031] 200···flow channel

[0032] 10b···Upstream side valve

[0033] 10c···Upstream pressure sensor

[0034] 10d··· Fluid resistance

[0035] 10e···Downstream pressure sensor

[0036] 10f···Downstream side valve

[0037] 101··· Position Sensor

[0038] 30··· Valve Control Section

[0039] 40··· Convergence Pressure Calculation Department

[0040] P1···Upstream pressure

[0041] P2···Downstream pressure

[0042] P CONV ...convergence pressure

[0043] P T_CONV ...Target convergence pressure

[0044] V1···Upstream side volume

[0045] V2···Downstream side volume Detailed Implementation

[0046] The fluid control device having the pressure control system of the present invention will be described below with reference to the accompanying drawings.

[0047] <Device Composition>

[0048] The fluid control device 100 of this embodiment is used, for example, to supply gas as a fluid to a chamber 300 at a set flow rate in a semiconductor manufacturing process. Here, the set flow rate is a step signal that increases or decreases in a step-like manner from one flow rate value to another. The flow rate implemented by the fluid control device 100 follows such a set flow rate for a predetermined time, and keeps the noise level in the steady state within an acceptable range.

[0049] Specifically, such as Figure 1 As shown, the fluid control device 100 includes: fluid devices 10a to 10f such as sensors and valves installed on the gas flow channel 200; and a control mechanism COM that controls the fluid devices 10a to 10f.

[0050] In this embodiment, the fluid devices 10a to 10f consist of a supply pressure sensor 10a, an upstream valve 10b, an upstream pressure sensor 10c, a fluid resistance 10d, a downstream pressure sensor 10e, and a downstream valve 10f, which are arranged sequentially from the upstream side relative to the flow channel 200. Here, the fluid resistance 10d is, for example, a laminar flow element that generates a pressure difference across it corresponding to the flow rate of the gas passing through it.

[0051] The supply pressure sensor 10a is used to monitor the pressure of the gas supplied from the upstream side. Furthermore, the supply pressure sensor 10a can be omitted when ensuring a stable supply pressure.

[0052] The upstream pressure sensor 10c measures the upstream pressure P1 of the fluid resistance 10d in the flow channel 200. Specifically, the upstream pressure sensor 10c measures the upstream pressure P1, which is the pressure of the gas in the volume V1 of the flow channel 200 that fills the space between the upstream valve 10b and the fluid resistance 10d.

[0053] The downstream pressure sensor 10e measures the downstream pressure P2 of the fluid resistance 10d in the flow channel 200. Specifically, the downstream pressure sensor 10e measures the downstream pressure P2, which is the pressure of the gas filling the volume V2, i.e., the downstream volume V2, between the fluid resistance 10d and the downstream valve 10f in the flow channel 200.

[0054] In this embodiment, the upstream valve 10b and the downstream valve 10f are identical valves, such as piezoelectric valves that are driven by an actuator, such as a piezoelectric element, to allow the valve body to contact or separate from the valve seat. The upstream valve 10b and the downstream valve 10f change their valve opening degree according to the voltage input as an operating quantity. Furthermore, position sensors 101 that detect the position of the valve body relative to the valve seat are provided in both the upstream valve 10b and the downstream valve 10f. By using the position detected by the position sensors 101, flow control can be performed with high precision using both the upstream valve 10b and the downstream valve 10f.

[0055] The control unit COM is, for example, a so-called computer equipped with a CPU, memory, A / D converter, D / A converter, input / output devices, etc. It executes a flow control program stored in memory to make various devices cooperate, at least performing the functions of a flow calculation unit 20 and a valve control unit 30.

[0056] The flow calculation unit 20 calculates the flow rate based on the upstream pressure P1 and the downstream pressure P2. Here, the flow calculation unit 20 uses an existing formula to calculate the gas flow rate, i.e., the resistance flow rate, flowing through the fluid resistance 10d based on the upstream pressure P1 and the downstream pressure P2. Furthermore, the flow calculation unit 20 can also calculate the gas flow rate, i.e., the upstream valve flow rate, flowing through the upstream valve 10b based on the resistance flow rate and the upstream pressure P1, and can also calculate the gas flow rate, i.e., the downstream valve flow rate, flowing through the downstream valve 10f based on the resistance flow rate and the downstream pressure P2.

[0057] The valve control unit 30 performs feedback control on at least one of the upstream valve 10b and the downstream valve 10f in a manner that makes the flow rate value calculated by the flow calculation unit 20 approach a predetermined flow rate target value. Alternatively, the valve control unit 30 may not perform flow control on the upstream valve 10b, but instead perform feedback control on the upstream valve 10b in a manner that makes the upstream pressure P1 obtained by the upstream pressure sensor 10c approach a predetermined pressure target value. Similarly, the valve control unit 30 may not perform flow control on the downstream valve 10f, but instead perform feedback control on the downstream valve 10f in a manner that makes the downstream pressure P2 obtained by the downstream pressure sensor 10e approach a predetermined pressure target value.

[0058] <Convergence Pressure Control in Enclosed Spaces>

[0059] Furthermore, the control device COM of the fluid control apparatus 100 in this embodiment has the function of controlling the convergence pressure of the closed space formed when the upstream side valve 10b and the downstream side valve 10f are completely closed. Here, the convergence pressure of the closed space is the pressure that stabilizes after a predetermined time after the upstream side valve 10b and the downstream side valve 10f are closed.

[0060] Specifically, the control device COM also includes a convergence pressure calculation unit 40, which uses at least one of the upstream pressure P1 and the downstream pressure P2 of the fluid resistance 10d in the flow channel 200 to calculate the convergence pressure P of the enclosed space when the upstream valve 10b is completely closed. CONV Furthermore, the valve control unit 30 measures the calculated convergence pressure P. CONV With the specified target convergence pressure P T_CONV The comparison is performed, and based on the comparison result, the upstream valve 10b is completely closed.

[0061] The convergence pressure calculation unit 40 uses at least one of the upstream pressure P1 and the downstream pressure P2, which are related to the fluid resistance 10d in the flow channel 200, to sequentially (in real time) calculate the convergence pressure P in process control. CONV Specifically, the convergence pressure calculation unit 40 uses the upstream pressure P1 of the fluid resistance 10d, the downstream pressure P2 of the fluid resistance 10d, the flow channel volume (upstream volume) V1 between the fluid resistance 10d and the upstream valve 10b, and the flow channel volume (downstream volume) V2 between the fluid resistance 10d and the downstream valve 10f to calculate the convergence pressure P. CONV .

[0062] In this embodiment, the convergence pressure calculation unit 40 uses the following formula to calculate the convergence pressure P in the closed space formed between the upstream valve 10b and the downstream valve 10f. CONV Additionally, the convergence pressure P calculated by the convergence pressure calculation unit 40... CONV The calculation is not limited to using the following formula; a lookup table can also be used. Here, when using a lookup table, it is possible to consider using the upstream pressure P1, downstream pressure P2, and convergence pressure P of the enclosed space. CONV The three parameters serve as a lookup table for each axis.

[0063] [Mathematical Expression 1]

[0064]

[0065] Among them, P CONV P1 is the convergence pressure of the enclosed space, P2 is the upstream pressure of the fluid resistance 10d, V1 is the flow channel volume between the fluid resistance 10d and the upstream valve 10b, and V2 is the flow channel volume between the fluid resistance 10d and the downstream valve 10f.

[0066] like Figure 2 As shown, the calculated convergence pressure P CONV Become the specified target convergence pressure P T_CONVAt this point, the valve control unit 30 completely closes the upstream valve 10b. Here, based on the pressure at which the set flow rate can flow through full scale (100%) immediately after opening the upstream valve 10b and downstream valve 10f, a predetermined target convergence pressure P is set. T_CONV .

[0067] Next, the closed space between the upstream valve 10b and the downstream valve 10f is controlled to achieve the target convergence pressure P. T_CONV This will be explained in terms of a series of actions.

[0068] First, the gas flow is cut off from the normal gas supply state through the flow channel 200 by completely closing the upstream valve 10b and the downstream valve 10f. Here, the downstream valve 10f is completely closed after the upstream valve 10b is completely closed.

[0069] Furthermore, after completely closing the upstream valve 10b and the downstream valve 10f to cut off the flow channel 200, the upstream valve 10b is opened, allowing gas to flow into the space between the upstream valve 10b and the downstream valve 10f. At this time, the upstream pressure sensor 10c detects the upstream pressure P1, and the downstream pressure sensor 10e detects the downstream pressure P2.

[0070] The convergence pressure calculation unit 40, which obtains the upstream side pressure P1 and the downstream side pressure P2, calculates the convergence pressure P in real time during the period when gas flows into the space between the upstream side valve 10b and the downstream side valve 10f. CONV The valve control unit 30 sequentially acquires the convergence pressure P calculated by the convergence pressure calculation unit 40. CONV and the specified target convergence pressure P T_CONV Comparisons were made. Furthermore, when the calculated convergence pressure P... CONV Become the specified target convergence pressure P T_CONV At that time, the valve control unit 30 completely closes the upstream valve 10b (refer to...). Figure 2 Therefore, the pressure in the closed space between the upstream valve 10b and the downstream valve 10f converges to the specified target convergence pressure P after a specified time. T_CONV Furthermore, subsequently, when gas is supplied to the chamber, the upstream valve 10b and the downstream valve 10f are controlled according to the specified set flow rate.

[0071] <Effects of this implementation method>

[0072] The fluid control device 100 of this embodiment, configured in this way, calculates the convergence pressure P of the enclosed space when the upstream valve 10b is completely closed, using at least one of the upstream pressure P1 and the downstream pressure P2 of the fluid resistance 10d. CONV The calculated convergence pressure PCONV With the specified target convergence pressure P T_CONV A comparison is made, and based on the comparison result, the upstream valve 10b is completely closed, thus enabling the control of the convergence pressure P in the enclosed space. CONV While suppressing overshoot, high-speed control is performed.

[0073] <Other Implementation Methods>

[0074] For example, in the embodiment described, the convergence pressure P is calculated using the upstream pressure P1 of the fluid resistance 10d, the downstream pressure P2 of the fluid resistance 10d, the flow channel volume V1 between the fluid resistance 10d and the upstream valve 10b, and the flow channel volume V2 between the fluid resistance 10d and the downstream valve 10f. CONV However, the convergence pressure P can also be calculated using only one of the upstream pressure P1 and the downstream pressure P2 of the fluid resistance 10d. CONV In this case, one of the upstream pressure P1 and downstream pressure P2 of the fluid resistance 10d is pre-calculated, along with the convergence pressure P. CONV The relationship is used to calculate the convergence pressure P. CONV .

[0075] Furthermore, the embodiment is configured such that, when controlling the convergence pressure, the calculated convergence pressure P... CONV With the specified target convergence pressure P T_CONV If the conditions are met, the upstream valve 10b is completely closed. However, it can also be configured such that, based on the calculated convergence pressure P... CONV Exceeding the target convergence pressure P T_CONV In the case of, or with a pre-set target convergence pressure P T_CONV The judgment range is used as a benchmark and is within the calculated convergence pressure P. CONV If the condition falls within the judgment range, completely close the upstream valve 10b.

[0076] Furthermore, in the aforementioned embodiment, a closed space is formed downstream of the upstream valve 10b by completely closing the downstream valve 10f. However, it is also possible to form a closed space downstream of the upstream valve 10b without completely closing the downstream valve 10f. For example, as... Figure 3As shown, the configuration can be as follows: a flow channel 200 with a fluid resistance 10d is connected to a sealed container 400, thereby forming a closed space downstream of the fluid resistance 10d. In this configuration, the convergence pressure calculation unit 40 can calculate the convergence pressure P using the upstream pressure of the fluid resistance 10d, the downstream pressure of the fluid resistance 10d, the flow channel volume between the fluid resistance 10d and the upstream valve 10b, and the volume of the flow channel downstream of the fluid resistance 10d and the sealed container 400. CONV .

[0077] The convergence pressure calculation unit 40 in the described embodiment can also correct for the time-dependent changes in the volume of the enclosed space or flow channel 200 and calculate the convergence pressure P. CONV Alternatively, the target convergence pressure can be changed by considering the time-varying volume of the enclosed space or flow channel 200. Furthermore, an alarm output unit can be provided, which outputs an alarm signal when the convergence pressure in the enclosed space has a difference of more than a predetermined value relative to the target convergence pressure, based on the calculated convergence pressure control result.

[0078] Furthermore, there exists a situation where the positional accuracy of the fluid resistance (laminar element) changes due to the machining accuracy of the fluid resistance, resulting in variations in the upstream volume V1 and the downstream volume V2. In this case, the convergence pressure calculation unit 40 can be configured to correct for the volume changes caused by the machining accuracy of the fluid resistance (laminar element).

[0079] Furthermore, in the above embodiment, it is a dual-valve configuration with an upstream valve 10b and a downstream valve 10f, but it can also be a single-valve configuration with only the upstream valve 10b.

[0080] Furthermore, in the described embodiment, a fluid control device equipped with a pressure control system was described, but it may also be a single pressure control system unit not assembled with a fluid control device.

[0081] Furthermore, the fluid resistance 10d in the embodiment is a laminar flow element, but it can be any resistance body that generates a pressure difference in the flow channel, such as a throttling orifice.

[0082] Furthermore, various modifications and combinations of implementation methods are possible as long as they do not violate the spirit of this invention.

Claims

1. A pressure control system, characterized in that, The pressure control system incorporates fluid resistance in the flow channels forming the enclosed space, and controls the pressure of the enclosed space by controlling an upstream valve located upstream of this fluid resistance. The enclosed space is formed by completely closing the upstream valve and the downstream valve located on the downstream side of the flow channel, which is positioned on the downstream side of the fluid resistance. The pressure control system includes: The convergence pressure calculation unit uses the upstream pressure of the fluid resistance in the flow channel, the downstream pressure of the fluid resistance, the flow channel volume between the fluid resistance and the upstream valve, and the flow channel volume between the fluid resistance and the downstream valve to calculate the convergence pressure of the enclosed space when the upstream valve is completely closed. as well as The valve control unit compares the calculated convergence pressure with the specified target convergence pressure, and based on the comparison result, completely closes the upstream valve.

2. The pressure control system according to claim 1, characterized in that, When the calculated convergence pressure exceeds the specified target convergence pressure, the valve control unit completely closes the upstream valve.

3. The pressure control system according to claim 1, characterized in that, The convergence pressure calculation unit calculates the convergence pressure using the following formula: Among them, P CONV P1 is the upstream pressure of the fluid resistance, P2 is the downstream pressure of the fluid resistance, V1 is the flow channel volume between the fluid resistance and the upstream valve, and V2 is the flow channel volume between the fluid resistance and the downstream valve.

4. The pressure control system according to claim 1, characterized in that, The convergence pressure calculation unit calculates the convergence pressure in real time.

5. The pressure control system according to claim 1, characterized in that, The convergence pressure calculation unit corrects for the time-dependent changes in the volume of the enclosed space or the flow channel and calculates the convergence pressure.

6. The pressure control system according to claim 1, characterized in that, A position sensor is provided on the upstream valve to detect the position of the valve body relative to the valve seat.

7. The pressure control system according to claim 1, characterized in that, A position sensor is provided on the downstream valve to detect the position of the valve body relative to the valve seat.

8. A pressure control method, characterized in that, A fluid resistance is provided in the flow channel that forms a closed space by completely closing the upstream and downstream valves. The pressure of the closed space is controlled by controlling the upstream valve located upstream of the fluid resistance. The pressure control method includes: The convergence pressure calculation step involves using the upstream pressure of the fluid resistance in the flow channel, the downstream pressure of the fluid resistance, the flow channel volume between the fluid resistance and the upstream valve, and the flow channel volume between the fluid resistance and the downstream valve to calculate the convergence pressure of the enclosed space when the upstream valve is completely closed; and The valve control step involves comparing the calculated convergence pressure with the specified target convergence pressure, and based on the comparison result, completely closing the upstream valve.

9. A storage medium storing a pressure control program, characterized in that, The pressure control program is used in a pressure control system that has fluid resistance in the flow channel forming a closed space. The pressure in the closed space is controlled by controlling an upstream valve located upstream of the fluid resistance. The closed space is formed by completely closing both the upstream valve and a downstream valve located downstream of the fluid resistance in the flow channel. The computer functions as both a convergence pressure calculation unit and a valve control unit by executing the pressure control program. The convergence pressure calculation unit uses the upstream pressure of the fluid resistance in the flow channel, the downstream pressure of the fluid resistance, the flow channel volume between the fluid resistance and the upstream valve, and the flow channel volume between the fluid resistance and the downstream valve to calculate the convergence pressure of the enclosed space when the upstream valve is completely closed. The valve control unit compares the calculated convergence pressure with the specified target convergence pressure, and based on the comparison result, completely closes the upstream valve.

10. A pressure control system, characterized in that, The pressure control system incorporates fluid resistance in the flow channels forming the enclosed space, and controls the pressure of the enclosed space by controlling an upstream valve located upstream of this fluid resistance. The enclosed space is formed by the upstream valve and a sealed container connected to the downstream side of the fluid resistance on the flow channel. The pressure control system includes: The convergence pressure calculation unit uses the upstream pressure of the fluid resistance in the flow channel, the downstream pressure of the fluid resistance, the flow channel volume between the fluid resistance and the upstream valve, and the volume of the flow channel downstream of the fluid resistance and the sealed container to calculate the convergence pressure of the enclosed space when the upstream valve is completely closed. as well as The valve control unit compares the calculated convergence pressure with the specified target convergence pressure, and based on the comparison result, completely closes the upstream valve.

11. A pressure control method, characterized in that, A fluid resistance is provided in the flow channel constituting the enclosed space. The pressure of the enclosed space is controlled by controlling an upstream valve located upstream of the fluid resistance. The enclosed space is composed of the upstream valve and a sealed container connected to the downstream side of the fluid resistance in the flow channel. The pressure control method includes: The convergence pressure calculation step uses the upstream pressure of the fluid resistance in the flow channel, the downstream pressure of the fluid resistance, the flow channel volume between the fluid resistance and the upstream valve, and the volume of the flow channel downstream of the fluid resistance and the sealed container to calculate the convergence pressure of the enclosed space when the upstream valve is completely closed; and The valve control step involves comparing the calculated convergence pressure with the specified target convergence pressure, and based on the comparison result, completely closing the upstream valve.

12. A storage medium storing a pressure control program, characterized in that, The pressure control program is used in a pressure control system that has fluid resistance in the flow channel forming the enclosed space. The pressure in the enclosed space is controlled by controlling an upstream valve located upstream of the fluid resistance. The enclosed space is composed of the upstream valve and a sealed container connected to the downstream side of the fluid resistance in the flow channel. The computer functions as both a convergence pressure calculation unit and a valve control unit by executing the pressure control program. The convergence pressure calculation unit uses the upstream pressure of the fluid resistance in the flow channel, the downstream pressure of the fluid resistance, the flow channel volume between the fluid resistance and the upstream valve, and the volume of the flow channel downstream of the fluid resistance and the sealed container to calculate the convergence pressure of the enclosed space when the upstream valve is completely closed. The valve control unit compares the calculated convergence pressure with the specified target convergence pressure, and based on the comparison result, completely closes the upstream valve.

Images