JP2011025125A - Dissolved oxygen concentration control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continuously detect the dissolved oxygen concentration of a closed piping passage. <P>SOLUTION: A dissolved oxygen concentration control system including the closed piping passage 1, and a deaeration passage 4 whose both ends are connected to the close piping passage 1 and which is equipped with a feed water pump 2 and a deaerator 3, includes a sensor 22 which detects the dissolved oxygen concentration of water to be deaerated in the deaeration passage 4, a bypass passage 5 which is connected parallel to the deaerator 3, a flow control valve means 6, 8 which controls the flow of the water to be deaerated to the deaerator 3 and the bypass passage 5, and a controller 9 which controls the operation of the deaerator 3 and controls the flow control valve means 6, 8 so as to make the water to be deaerated flow to the bypass passage 5 when the operation of the deaerator 3 is stopped. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a dissolved oxygen concentration management system that manages a dissolved oxygen concentration in a closed pipe flow path.

  A deaeration system including a sealed piping channel and a degassing processing channel having both ends connected to the sealed piping channel and provided with a water supply pump and a deaeration device is known from Patent Document 1.

  In this conventional degassing system, it is conceivable to provide a sensor for detecting the dissolved oxygen concentration in the degassing treatment flow path to detect the dissolved oxygen concentration in the sealed piping flow path. In that case, when continuously operating the deaerator, the dissolved oxygen concentration can be detected continuously without any problem, but when the deaerator is stopped for the purpose of energy saving, the dissolved oxygen concentration should be reduced. It is difficult to detect continuously. In addition, since it is difficult to continuously detect the dissolved oxygen concentration, it is also difficult to control the operation of the deaerator based on the dissolved oxygen concentration in the sealed pipe flow path.

Japanese Patent No. 2912422

  The main problem to be solved by the present invention is to continuously detect the dissolved oxygen concentration in the sealed piping channel, and the sub-task is to continuously notify the dissolved oxygen concentration in the sealed piping channel. The operation of the deaerator is made controllable based on the dissolved oxygen concentration in the closed pipe flow path.

  This invention was made in order to solve the said subject, and invention of Claim 1 provided the water supply pump and the deaeration apparatus by which both ends were connected to the sealed piping flow path, and this sealed piping flow path In a dissolved oxygen concentration management system comprising a deaeration treatment channel, a sensor that detects a dissolved oxygen concentration of degassed water in the deaeration treatment channel, and a bypass channel connected in parallel with the deaeration device; A flow control valve means for controlling the flow of the degassed water to the deaeration device and the bypass flow channel, and the operation of the deaeration device, and the bypass flow channel when the deaeration device is stopped. And a control means for controlling the flow control valve means so as to allow the deaerated water to flow through.

  According to the first aspect of the present invention, degassed water can be allowed to flow to the sensor even when the deaeration device is stopped, and the dissolved oxygen concentration in the sealed pipe channel is continuously detected by the sensor. can do.

  In addition, the invention according to claim 2 is provided with notifying means for notifying the output of the sensor according to claim 1, and the control means inputs the detection value of the sensor and dissolves oxygen based on the detection value. The concentration is notified by the notification means.

  According to invention of Claim 2, in addition to the effect by the invention of Claim 1, there exists an effect that the dissolved oxygen concentration of the said sealed piping flow path can be alert | reported continuously.

Further, the invention according to claim 3 is the control device according to claim 1 or 2, wherein the control means is configured such that the detected value of the sensor is not less than a first set value or the set time has elapsed since the deaerator was stopped. When the time elapses, the deaeration device is operated, and the operation of the deaeration device is stopped when the detected value is equal to or lower than a second set value lower than the first set value.

  According to the third aspect of the present invention, in addition to the effect of the first or second aspect of the invention, the dissolved oxygen concentration in the sealed pipe flow path is accurately detected, and the deaeration device There is an effect that the operation can be controlled and the dissolved oxygen concentration in the sealed pipe flow path can be managed appropriately.

  According to this invention, the dissolved oxygen concentration management system which can detect the dissolved oxygen concentration of the said sealed piping flow path continuously can be provided.

It is a schematic explanatory drawing which shows the structure of Example 1 of the dissolved oxygen concentration management system which concerns on this invention. It is a flowchart figure explaining the principal part of the control procedure of the Example 1. FIG.

  Next, an embodiment of the dissolved oxygen concentration management system of the present invention will be described. The embodiment of the present invention is suitably implemented in a dissolved oxygen concentration management system that manages the dissolved oxygen concentration in a sealed pipe flow path.

  This embodiment will be specifically described. This embodiment includes a sealed pipe flow path, and a deaeration process flow path having both ends connected to the closed pipe flow path and provided with a water supply pump (also referred to as a circulation pump) and a deaeration device. It is a dissolved oxygen concentration management system.

  In this embodiment, a sensor for detecting the dissolved oxygen concentration (hereinafter referred to as DO) of the degassed water in the degassing treatment channel and a bypass flow connected in parallel with the degassing device. A flow control valve means for controlling the flow of water to be deaerated to the deaeration device and the bypass flow path, and controlling the operation of the deaeration device, and the deaeration during operation of the deaeration device And a control means for controlling the flow control valve means to flow the deaerated water to the apparatus and to flow the deaerated water to the bypass flow path when the deaerator is stopped.

  In the dissolved oxygen concentration management system according to this embodiment, during operation of the deaeration device, degassed water from the sealed piping flow path is supplied to the deaeration device, and the deaeration device is stopped ( Hereinafter, simply referred to as “stop”), the supply of the deaerated water to the deaerator is stopped, and the deaerated water is supplied to the bypass channel. The flow of the deaerated water to the bypass flow path is to form the flow of the deaerated water from the sealed pipe flow path to the DO detection part of the sensor even when the deaerator is stopped. It is. Thus, the sensor continuously detects DO to be deaerated water. Although it is possible to detect DO by the sensor without flowing deaerated water through the bypass flow path when the deaerator is stopped, it is a detection in a state where the flow of deaerated water is stopped. It does not mean that the DO of water in the sealed pipe flow path is being measured. In addition, it can also comprise so that a small amount of to-be-deaerated water may flow into a bypass flow path during the driving | operation of the said deaeration apparatus.

  The continuous detection value of DO of the sensor is preferably used in the following three modes in this embodiment. A 1st aspect is provided with the alerting | reporting means which alert | reports the output of the said sensor, The said control means inputs the detection value of the said sensor, and alert | reports the dissolved oxygen concentration based on the said detected value in the said alerting | reporting means. It is. In the first aspect, the detected value is converted into a dissolved oxygen concentration by the control means and notified by the notification means.

  According to this first aspect, the system administrator and the maintenance staff can accurately know the DO value of the water flowing through the sealed piping channel by the notification means regardless of whether the deaerator is operated or stopped. It can be used for system management and maintenance.

  In a second aspect, the detection means operates the deaerator when the detected value of the sensor is equal to or greater than the first set value, or when a set time elapses from when the deaerator is stopped. This is a mode in which the operation of the deaeration device is stopped when the value becomes equal to or less than a second set value lower than the first set value.

  In this second aspect, the control means determines that the DO of water in the sealed pipe flow path has increased (deteriorated) when the detection value of the sensor is equal to or higher than the first set value. The deaerator is operated. Then, when the detected value is equal to or lower than the second set value lower than the first set value, the operation of the deaerator is stopped. Thus, based on the detection value of the sensor, the operation of the deaeration device can be controlled automatically and so that the DO of water in the sealed pipe flow path falls within a predetermined value.

  Further, the control means operates the deaeration device when a set time has elapsed since the operation of the deaeration device was stopped. When the deaeration device is stopped for a long time, re-dissolution of oxygen occurs in the deaeration device and DO rises, but the deaeration device is operated every time the set time elapses. An excessive increase in DO can be prevented. The operation of the deaerator is stopped when the detected value is equal to or lower than a second set value that is lower than the first set value.

  The third aspect is a combination of the control of the first aspect and the control of the second aspect.

  The embodiment of the present invention is not limited to the first to third embodiments, but the detection value data of the sensor is stored in the storage means, and when necessary, to another management device The detection value data is transmitted and used in the management device.

  Here, the component which comprises the dissolved oxygen concentration management system of embodiment of this invention is demonstrated. The sealed pipe flow path is, for example, a cooling water circulation circuit of a semiconductor manufacturing apparatus, but is not limited thereto.

  The water supply pump is a pump that sucks a part of the water circulating in the sealed pipe flow path, supplies the water to the deaeration device and the bypass flow path, and returns it to the sealed pipe flow path Good, no matter what kind.

  The deaeration device is preferably a membrane deaeration device that generates low DO (eg, about 20 μg / L) deaeration water, but is not limited thereto, and a membrane using a deaeration membrane It can be set as deaeration apparatuses other than a deaeration apparatus. As the low DO deaerator, a deaerator disclosed in JP-A-5-103908 can be employed. When the membrane deaerator is used, the deaerator can be configured by including a water-sealed vacuum pump for vacuum deaeration and a chiller for cooling the sealed water of the water-sealed vacuum pump. The deaeration device can be composed of not only one unit but also a plurality of deaeration devices connected in parallel to each other.

  The sensor is not limited to a specific type of sensor, but can detect a low DO value as described above, and preferably can detect DO at a small flow rate (200 to 300 cc / min). To do. Preferably, a detection flow path is configured in parallel with the water supply pump so as not to drain the sampling water of the sensor outside the deaeration process flow path.

  The flow control valve means (also referred to as switching means) is preferably constituted by a valve that selectively switches the degassed water in the sealed pipe flow path between the deaerator side and the bypass flow path side. To do. This valve may be composed of a plurality of valves or a single three-way switching valve. When a part of the deaerated water is allowed to flow through the bypass channel during operation of the deaeration device, the valve provided in the bypass channel can be a valve whose opening degree can be adjusted.

  The notification means is preferably a display, but can be a printing means for printing out the detected DO value on paper or the like, or a voice notification means.

  Next, the dissolved oxygen concentration management system according to the first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic explanatory diagram illustrating a configuration of the first embodiment, and FIG. 2 is a flowchart illustrating a main part of a control procedure of the first embodiment.

  The dissolved oxygen concentration management system according to the first embodiment of the present invention includes a sealed piping channel (a channel can be referred to as a line) 1, a deaeration treatment channel 4 provided with a feed water pump 2 and a deaeration device 3. And a bypass passage 5 connected in parallel with the deaeration device 3 as a main part. The deaeration channel 4 is connected to the sealed pipe channel 1 at both ends. Cooling water of a semiconductor manufacturing apparatus (not shown) is circulated in the sealed pipe flow path 1.

  In the deaeration treatment channel 4, a sensor 5 that detects a dissolved oxygen concentration (hereinafter referred to as DO) of the deaerated water, and a flow of the deaerated water are connected to the deaerator 3 and the bypass flow. An inlet-side first electromagnetic on-off valve (hereinafter simply referred to as an inlet-side first electromagnetic valve) 6, an outlet-side first electromagnetic on-off valve (hereinafter simply referred to as an outlet-side first electromagnetic on-off valve) as a flow control valve means for selectively switching to the path 5 And a second electromagnetic on-off valve (hereinafter simply referred to as a second electromagnetic valve) 8. Then, the operation of the deaeration device 3 is controlled, the deaerated water is allowed to flow to the deaeration device 3 during the operation of the deaeration device 3, and the bypass channel 5 is covered when the deaeration device 3 is stopped. A controller 9 is provided as a control means for controlling the on-off valves 7, 8, 9, etc. so that deaerated water flows.

  In the deaeration treatment channel 4, a channel from the inlet 10 to the first electromagnetic valve 6 on the inlet side is referred to as an outgoing pipe 11, and the deaerated water or the deaerated water and the deaerated water are used. Between the outlet 12 and the outlet-side first electromagnetic valve 7 is referred to as a return pipe 14. A flow path on the deaerator side between the inlet side first electromagnetic valve 6 and the outlet side first electromagnetic valve 7 is referred to as a deaeration side pipe 15.

  A first manual on-off valve (hereinafter simply referred to as a first manual valve) 16 and a third electromagnetic on-off valve (hereinafter simply referred to as a third electromagnetic valve) 17 are provided in the vicinity of the inlet 10 of the outgoing pipe 11. It is provided in this order along the flow direction of the deaerated water. In the vicinity of the outlet 12 of the return pipe 14, a second manual on-off valve (hereinafter simply referred to as a second manual valve) 18 and a fourth electromagnetic on-off valve (hereinafter simply referred to as a fourth electromagnetic valve) 19 are provided. It is provided in this order along the counter-flow direction of the deaerated water. The first manual valve 16 and the second manual valve 18 are valves for separating the degassing process flow path 4 from the sealed piping flow path 1 when the degassing device 3 and the like are inspected and repaired.

  A first detection channel 21 for detecting (measuring) DO of deaerated water is provided in parallel with the water supply pump 2. The first detection flow path 21 includes a first DO sensor 22 that detects DO of deaerated water, a first flow sensor 23 having a flow rate adjustment function, and a desorption from the upstream side of the water supply pump 2. A first check valve 24 for blocking the flow of steam is provided. The first DO sensor 22 uses a sensor capable of detecting DO at a small flow rate (200 to 300 cc / min), and enables the DO detection by the flow rate adjusting function of the first flow rate sensor 23. This flow rate adjusting function can be performed by a flow rate adjusting unit different from the sensor, regardless of the function of the flow rate sensor.

  A first pressure reducing valve 25 is provided on the upstream side of the deaeration device 3 of the deaeration side pipe 15 to reduce the pressure of the inflowing deaerated water, and a downstream having a flow rate adjusting function is provided. A two-flow sensor 26 and a second check valve 27 for preventing the inflow of deaerated water flowing through the bypass flow path 5 are provided.

  The degassing device 3 is a membrane degassing device that generates low DO degassed water of about 20 μg / L, a membrane degassing unit (not shown), a water ring vacuum pump 28, and a water ring vacuum pump. And a chiller 29 for cooling the 28 sealed water.

  The bypass flow path 5 includes a second pressure reducing valve 30 and a third check valve 31 that prevents inflow of deaerated water from the deaerator 3 side.

  Further, in the first embodiment, the second detection flow path 32 for detecting DO of the deaerated water deaerated by the deaerator 3 is used as the pump for the return pipe 14 and the forward pipe 11. 2 is connected to the upstream side. The second detection flow path 32 includes a second DO sensor 33 that detects DO of deaerated water, a third flow sensor 34 having a flow rate adjusting function, and water to be deaerated from the outgoing pipe 11 side. A fourth check valve 35 for blocking the flow is provided. The second DO sensor 33 is a sensor that detects DO with a small flow rate similar to that of the first DO sensor 22. The deaerated water flowing through the second detection flow path 32 is configured not to affect the DO detection of the deaerated water of the first DO sensor 22.

  The controller 9 includes a microprocessor, storage means, and the like, and inputs signals from the first DO sensor 22, the second DO sensor 33, the first to third flow rate sensors 23, 26, 34, and the like. Based on the control procedure stored in advance, the deaeration device 3, the feed water pump 2, the first to fourth electromagnetic valves 6, 8, 9, 17, 19 and the display 36 are controlled.

  The control procedure of the controller 9 is such that the DO continuous notification procedure for continuously reporting DO of deaerated water and the DO value of water in the sealed pipe flow path 1 automatically fall within a predetermined value. And an automatic DO control procedure for controlling the operation of the deaeration device 3.

  In the first embodiment, the DO continuous notification procedure is based on the detection values of the first DO sensor 22 and the second DO sensor 33, and the DO of deaerated water and the DO of degassed water are respectively notified by the alarm device. It is comprised as the procedure notified by 36.

  Further, the automatic DO control procedure is performed when the detected value of the first sensor 22 exceeds the first set value DO1 (or more) or when the set time T1 elapses from when the deaerator 3 is stopped. The deaeration device 3 is operated, and the operation of the deaeration device is stopped when the detected value becomes less than the second set value DO2 (which may be below) lower than the first set value DO1. The control procedure of the first embodiment is shown in FIG.

  Here, the operation of the dissolved oxygen concentration management system of the first embodiment will be described with reference to FIG. The first manual valve 16 and the second manual valve 18 are opened in advance. Referring to FIG. 2, in processing step S <b> 1 (hereinafter, processing step SN is simply referred to as SN), an operation of an automatic operation switch (not shown) is accepted, and a first set time of a built-in timer of the controller 9. Time measurement of T1 and the second set time T2 is started.

  In S2, the third solenoid valve 17 and the fourth solenoid valve 19 are opened, the second solenoid valve 8 is opened, and the first solenoid valves 6 and 7 are closed. Water treatment (hereinafter referred to as first bypass water treatment) is performed.

  By this first bypass water flow treatment, the cooling water in the sealed pipe flow path 1 is sucked by the water supply pump 2 and flows into the outgoing pipe 11 from the inlet 10 and then flows through the bypass flow path 5. It flows out from the outlet 12 to the sealed piping flow path 1. A part of the cooling water (degassed water) sucked by the water supply pump 2 is supplied to the first detection flow path 21 as sample water, and the degassed water flows to the first DO sensor 22, A part of the deaerated water is also supplied to the second detection flow path 32, and the deaerated water flows also to the second DO sensor 33.

  Next, in S3, it is determined whether or not the time measurement of the second set time T2 has ended. The second set time T2 is set to a time required for the operations of the first DO sensor 22 and the second DO sensor 33 to be stabilized. When the time T2 has elapsed, YES is determined in S3, the process proceeds to S4, and the detected DO by the first DO sensor 22 and the second DO sensor 33 is displayed on the display 36.

  Thus, when the deaeration device 3 is stopped, the deaerated water flows through the bypass flow path 5, so that the deaerated water flow is formed in the first DO sensor 22. In this way, the deaerated water, that is, the DO of the cooling water in the sealed piping channel 1 can be detected by the first DO sensor 22 even when the deaeration device 3 is stopped, and can be notified to the manager or the like.

  In S5, the first condition that the detection value of the first sensor 22 exceeds the first set value DO1 continues for the third set time T3, and the second condition that the time measurement of the first set time T1 ends. Determine if any are satisfied. If neither the first condition nor the second condition is satisfied, NO is determined and the process returns to S4.

  In S5, when either the first condition or the second condition is satisfied and YES is determined, the process proceeds to S6 and the operation of the deaerator 3 (the operation of the water-sealed vacuum pump 28 and the chiller 29) is performed. Including). At the same time, timing of the fourth set time T4 is started. The fourth set time T4 is set to a time required for the degree of vacuum in the deaeration device 3 to decrease to a predetermined value and the sealing water temperature to decrease to a predetermined value from the start of operation of the deaeration device 3. ing.

  Satisfying the first condition means deterioration of the cooling water quality of the closed pipe flow path 1, that is, DO has risen, and satisfying the second condition means that during the first set time T1. This means that the deaeration device 3 has never been operated.

  When the timing of time T4 is completed in S7, the process proceeds to S8 to perform a deaeration water passing process. In this deaeration water flow treatment, first, the first electromagnetic valves 6 and 7 are opened, and the time measurement of the fifth set time T5 is started. Next, after the time measurement of the fifth set time T5 is completed, the second electromagnetic valve 8 is closed and the first set time T1 is reset. Thus, since the operation of the deaeration device 3 is performed prior to the deaeration water flow treatment, it is possible to prevent the treated water having a high DO from being supplied to the sealed pipe flow path 1.

  By this degassing water flow treatment of S8, the cooling water of the sealed pipe flow path 1 is sucked by the water supply pump 2, flows into the forward pipe 11 from the inlet 10, and then passes through the degassing side pipe 15. The deaeration is performed by supplying the deaeration device 3.

During this deaeration water flow treatment, a part of the cooling water (degassed water) sucked by the water supply pump 2 is supplied to the first detection channel 21 as sample water, and the degassed water is the first degassed water. One DO sensor 22 flows. Thus, since the deaerated water flows to the first DO sensor 22 even when the deaerator 3 is in operation, the DO of the deaerated water is accurately detected and notified by the display 36. A part of the deaerated water that has been deaerated is supplied to the second detection flow path 32, the deaerated water flows through the second DO sensor 33, and DO of the deaerated water is detected. Notification is made on the display 36. In this deaeration water passing process, if it is determined that DO <DO1 based on the detection value of the first sensor 22, the third set time T3 is reset.

  Next, the process proceeds to S9, and it is determined whether DO <DO2 is continuously satisfied by the sixth set time T6 based on the detection value of the first sensor 22 by the deaeration water passing process of S8. If YES is determined, that is, it is determined that the deaeration process is unnecessary, the deaeration water passing process is terminated, and the second bypass water passing process of S10 is performed.

  This second bypass water flow treatment is common in that water flow to the deaeration device 3 is blocked and water flow to the bypass flow path 5 is performed. Different. In S10, first, the second electromagnetic valve 8 is opened, and the fifth set time T5 is reset. Next, the first solenoid valves 6 and 7 are closed and the deaeration device 3 is stopped with a delay of the seventh set time T7. In the second bypass water flow treatment, when DO> DO2 is determined based on the detection value of the first sensor 22, the sixth set time T6 and the seventh set time T7 are reset.

  Then, when it is determined in S11 that automatic driving is OFF, the process proceeds to S12, and an automatic driving end process is performed. In S12, the third electromagnetic valve 17 and the fourth electromagnetic valve 19 are closed, the feed water pump 2 is stopped, and the deaeration device 3 is stopped. If automatic operation OFF is not determined in S11, the process returns to S4, and the continuous DO notification process and the automatic DO control process described above are continuously performed.

  According to the first embodiment, the system administrator and the maintenance staff know the DO value of the water flowing through the sealed piping passage 1 accurately by the display 36 regardless of whether the deaerator 3 is operated or stopped. It can be used for system management and maintenance.

  Further, according to the first embodiment, since the first DO sensor 22 can continuously detect DO of the water to be deaerated, the deaeration is performed based on the detection value of the first DO sensor 22. By appropriately controlling the operation of the apparatus 3, the water DO in the sealed pipe flow path 1 can be kept within a predetermined range.

  Further, when the operation of the deaeration device 3 is stopped for a long time, the DO in the deaeration device 3 rises. According to the first embodiment, the first set time T1 elapses. Since the deaeration device 3 is operated, an excessive increase in the DO value can be prevented.

  The present invention is not limited to the first embodiment. For example, although the second detection flow path 32 is provided in the first embodiment, a dissolved oxygen concentration management system having a configuration in which the second detection flow path 32 is not provided as necessary can be provided.

DESCRIPTION OF SYMBOLS 1 Sealed piping flow path 2 Water supply pump 3 Deaeration apparatus 4 Deaeration process flow path 5 Bypass flow path 6 Inlet side 1st solenoid valve (flow control valve means)
8 Second solenoid valve (flow control valve means)
9 Controller (control means)
22 First DO sensor (sensor)

Claims (3)

In a dissolved oxygen concentration management system comprising a sealed pipe flow path and a deaeration treatment flow path having both ends connected to the closed pipe flow path and provided with a water supply pump and a deaeration device,
A sensor for detecting the dissolved oxygen concentration of the degassed water in the degassing treatment channel;
A bypass flow path connected in parallel with the deaeration device;
Flow control valve means for controlling the flow of degassed water to the deaeration device and the bypass channel;
And a control means for controlling the flow control valve means to control the operation of the deaeration device and to flow the deaerated water to the bypass channel when the operation of the deaeration device is stopped. Dissolved oxygen concentration management system. Informing means for informing the output of the sensor,
2. The dissolved oxygen concentration management system according to claim 1, wherein the control unit inputs a detection value of the sensor and notifies the dissolved oxygen concentration based on the detection value by the notification unit.   The control means operates the deaerator when a detection value of the sensor is equal to or greater than a first set value or when a set time elapses after the deaerator is stopped, and the detected value is the first set value. 3. The dissolved oxygen concentration management system according to claim 1, wherein the operation of the deaeration device is stopped when a lower second set value is reached. 4.

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