JPH01299439A - Controlling mechanism of flow rate of automatic pressure-reducing apparatus - Google Patents

Abstract

PURPOSE:To secure a prescribed quantity of sample water even when a main flow-rate regulating valve is put in an interrupted state with the reduction of pressure in an outlet piping, by providing a manifold in the outlet piping led out of a pressure- reducing mechanism, by supplying the reduced pressure sample water to a sample water analysis system from the manifold through a main flow-rate adjusting valve, and also by providing a bypass piping. CONSTITUTION:A manifold 30 is provided in a part of an outlet piping 18 so that the connections of a piping system branching in a complicated manner be simplified and made small in size, and a bypass piping 36 communicating with the downstream side of a flow-rate adjusting valve 22 of the piping 18 through a solenoid ON-OFF valve 32 and an auxiliary flow-rate adjusting valve 34 constructed of a needle valve is provided in a part of the manifold 30. When the water pressure of high-pressure sample water in an inlet piping 16 lowers and a pressure-reducing mechanism 10 turns to fail to operate in this condition, the pressure of the outlet piping 18 is detected by a pressure detector 26, the above valve 32 is put in an opened state by a controller 28, and thereby the sample water is made to flow in a prescribed quantity continuously to an analysis system through the bypass piping 36.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an automatic pressure reducing device, and in particular, when collecting high-pressure sample water in a sampling device for a thermal or nuclear power plant, it is possible to prevent changes in the source pressure of sample water. The outlet pressure of the pressure reducing device is always maintained constant without being affected, and even if the sample water source pressure drops significantly and the automatic pressure reduction function is lost, sample water at a predetermined flow rate can be continuously collected. This invention relates to a flow rate control structure of an automatic pressure reducing device.

[Conventional technology]

In thermal and nuclear power plant equipment, when high-pressure sample water is collected from a predetermined point in the boiler water circulation system and introduced into a water quality analyzer, it is desirable that the flow rate of the sample water be constant. A decompression mechanism is utilized.

Therefore, as a conventional pressure reduction mechanism, one in which the pressure reduction constant is fixed is often used. However, this type of pressure reducing mechanism has the disadvantage that when the source pressure of the sample water changes, the flow rate at the outlet of the pressure reducing mechanism changes. In addition, in order to automatically change the pressure reduction constant in response to such fluctuations in the sample water source pressure, we have developed a fluid operation cylinder in which an adjustment rod is inserted through the pressure reduction mechanism and one end of this adjustment rod is connected to a spool. A device has been proposed (Japanese Patent Publication No. 12806/1983) that controls a directional control valve for operating this operating cylinder, and the directional control valve based on a contact operating signal from a pressure detector. However, this type of automatic pressure reduction mechanism not only causes a control delay due to fluid pressure control, but also has low positioning accuracy, and also has various structural issues such as fluctuations in the pressure reduction constant due to leakage in the gland of the adjustment rod. There is a drawback.

From this point of view, conventionally, two pressure regulating thin tubes are provided, one end of which is provided with a joint to connect to the sample water pipe, the other end of which is provided with a joint to connect to the adjustment tube, and the inside of the adjustment tube is provided with a joint to connect to the sample water pipe. A decompression mechanism for a sampling device has been proposed that includes a core wire that moves forward and backward in the thin tube by an inserted feed screw, and an adjustment handle that operates the feed screw from the outside (Japanese Utility Model Publication No. 56-12592).

However, in the pressure reduction mechanism configured in this way, there is no structural problem such as fluctuations in the pressure reduction constant due to leakage etc. when controlling the core wire inserted into the pressure regulating thin tube by operating the feed screw. Automation, rapid and highly accurate control is difficult to achieve with conventional general control mechanisms.

Therefore, the present applicant has provided an inlet pressure regulating capillary tube and an outlet pressure regulating capillary tube, inserting a core wire whose one end is supported by a movable ring into these pressure regulating capillary tubes, and screwing a screw shaft into the movable ring. A pressure reducing mechanism is provided which supports this in a movable manner, and this pressure reducing mechanism is connected to the sample water piping to detect the outlet side pressure and adjust the screw shaft to set the sample water outlet pressure to a set value. A pressure transducer that generates a pressure signal on the sample water pipe on the outlet side of the pressure reducing mechanism, and a proportional controller that compares this pressure signal with a set pressure and provides an operating signal to the servo motor. , a gear is provided on a rotating shaft led out from the servo motor via a reducer, and the gear is meshed with a gear provided at one end of the screw shaft;
Furthermore, he developed an automatic pressure reducing device equipped with a potentiometer to detect the amount of rotation of the servo motor and configured to display core wire insertion, and filed a patent application (Japanese Patent Laid-Open No. 57-1003
Publication No. 36).

In the conventional pressure reduction mechanism described above, which uses two pressure adjustment thin tubes and a core wire that moves back and forth inside these thin tubes, the gap between the thin tubes and the core wire is extremely small. Contamination with water can easily cause water flow to be blocked or movement of the core wire to be stopped. Therefore, for example, when the movement of the core wire is stopped, the core wire is coupled and fixed to a common moving member within the adjustment pipe, a screw hole is carved in the moving member, and a feed screw is screwed into this screw hole.
By rotating this feed screw by external operation, the core wire is moved together with the movable member, so the movable member is prevented from moving in the direction of the screw axis, and as a result, the movable member is forced to rotate integrally with the feed screw. However, this not only twists and damages the two parallel core wires and makes them unusable, but also causes problems such as exerting tN (M) on the pressure regulating thin tube. Adjustment of the insertion position of the core wire into the thin tube converts rotational drive into reciprocating movement, so the position of the core wire is detected from the number of rotations of the feed screw, so when performing highly accurate positioning, the conversion coefficient must be set strictly. However, the occurrence of errors cannot be avoided due to machine differences, etc., and therefore, highly accurate positioning is difficult.Furthermore,
In conventional pressure reducing devices, the pressure regulating thin tube, regulating tube, and core wire are designed in advance so that they always have a certain relationship, and they are manufactured as an integral structure, so there is no risk of damage to parts of these components. Should be replaced entirely if damaged;
Furthermore, since the same applies when changing the adjustment range of the decompression conditions, there is a problem in that the cost for maintenance and design changes increases significantly. Moreover, when replacing such a pressure reducing device, the high-pressure sample water piping system must be temporarily shut off to separate the device, which is a disadvantage since it requires a great deal of time and effort. There is.

Therefore, the present applicant constructed a configuration in which the pressure adjustment thin tube, the core wire, and the adjustment tube are assembled so that they can be separated, and the forward and backward positions of the core wires are also adjusted while detecting the position using linear control means that performs linear motion. By doing so, we have developed a depressurization adjustment mechanism for automatic depressurizers that facilitates manufacturing, improves core wire positioning accuracy, enables precise depressurization adjustment, and simplifies maintenance and improves control performance. The patent application was filed as a concurrent patent application (1).

That is, the pressure reduction adjustment mechanism of this automatic pressure reduction device has a pair of parallel pressure adjustment holes, a connector at one end that communicates with the pressure adjustment hole for connection to external piping, and a a first pressure regulating tube having a core wire inserted into the pressure regulating hole so as to be movable back and forth; a first pressure regulating tube fluid-tightly coupled to the other end of the first pressure regulating tube via a fastener; a second pressure regulating pipe having a sliding rod provided with a coupling member to which a core wire is freely attached; A rack rod is arranged in parallel with the sliding rod, one end of this rack rod and the tip of the sliding rod are connected by a connecting member, and the rack rod is driven by a motor to move back and forth, so that the rack rod can be moved through the sliding rod. The invention is characterized in that it is provided with a control means for adjusting the position of the core wire within the pressure adjustment hole.

[Problem to be solved by the invention]

However, in conventional automatic pressure reduction devices, it is necessary to perform automatic pressure reduction control to maintain a constant pressure and flow rate suitable for supplying high-pressure sample water to the analyzer despite fluctuations in the source pressure of the sample water. For this reason, conventional devices employ an automatic pressure reduction control system shown in FIG. 4, for example. That is, the fourth
In the figure, reference numeral 10 indicates a pressure reduction mechanism, and 12 indicates an automatic pressure reduction control section for controlling this pressure reduction mechanism 10. The decompression mechanism 10 has a sample water supply port 14a and a sample water discharge port 14b.
and a supply port L4a and a discharge port 14, respectively.
An inlet pipe 16 for high-pressure sample water and an outlet pipe 18 for reduced-pressure sample water are connected to b. The inlet piping 16 is provided with an inlet opening/closing valve 20 that opens and closes automatically under constant pressure conditions and also opens and closes in response to a manual opening/closing command signal. Further, the outlet piping 18 is provided with a flow rate adjustment valve 22 consisting of a needle valve to communicate with the sample water analysis system, and a relief valve 24 and a pressure detector 26 are connected and arranged upstream of the flow N adjustment valve 22. ing.

The pressure signal detected by this pressure detector 26 is
The pressure is transferred to the controller 28, and the controller 28 compares the preset pressure setting value and the detected pressure value, calculates the deviation, and instructs the pressure reducing mechanism 10 to adjust the movement of the core wire in order to adjust the pressure according to this deviation. It is configured to send a control command to the automatic pressure reduction control section 1-2.

In the conventional reduced-pressure sample water flow rate control system configured as described above, when operating according to an automatic mode command, high-pressure sample water having a pressure within an allowable range is supplied to the high-pressure sample water inlet piping 16. If so, the automatic pressure reduction control unit 12 can implement appropriate pressure reduction feedback control via the controller 28 described above. However, for example, if the pressure of the high-pressure sample water supplied to the inlet pipe 16 is reduced below the allowable range, and the pressure reduction mechanism 10 reaches the lowest pressure reduction state (reduction value is 0), the flow rate adjustment valve 22 consisting of a needle valve will be closed at the outlet. Sufficient pressure cannot be obtained with the sample water in the pipe 18, and the valve is closed, and the supply of sample water to the analysis system Δ is stopped. Note that due to the pressure reduction of the high-pressure sample water supplied to the inlet piping 16, the inlet on-off valve 20 is automatically closed, but even if the artificial on-off valve 20 is opened manually in this case, the pressure reduction state remains. As long as continues, /fr
The L amount adjustment valve 22 is in a cutoff state.

In this way, if the source pressure of the high-pressure sample water decreases for some reason, continuous analysis of the sample water is important in order to determine the cause, especially for the safe operation of thermal and nuclear power plants. It is essential to do this. Therefore, as mentioned above, even if the source pressure of the sample water is significantly reduced and the pressure reducing function is lost in the pressure reducing mechanism, an automatic pressure reducing device equipped with a mechanism that can supply sample water with reduced pressure to the analysis system. Improvements are requested.

Therefore, the purpose of the present invention is to use a pressure detector to detect a state in which the pressure of high-pressure sample water in the inlet pipe connected to the pressure reduction mechanism is significantly reduced and the pressure reduction mechanism stops functioning, and to automatically open the valve in such a case. An automatic pressure reducing device with a simple configuration and easy control operation that allows the sample water whose pressure has been reduced by performing the original design to bypass the flow rate adjustment valve installed in the outlet piping and supply a predetermined amount of sample water to the analysis system. to provide a flow control mechanism.

[Means to solve the problem]

The flow rate control mechanism of the automatic pressure reducing device according to the present invention has a pair of parallel pressure adjustment holes, and an inlet pipe for high-pressure sample water and an outlet pipe for reduced-pressure sample water are connected to one end of the pair of pressure adjustment holes, respectively. a pressure reduction mechanism configured by connecting a core wire for pressure reduction and inserting a core wire for pressure reduction from the other end of the pressure adjustment hole; an automatic pressure reduction control section that automatically controls the insertion position of the core wire for pressure reduction with respect to the pressure adjustment hole; and the outlet piping. In an automatic pressure reducing device equipped with a controller that detects sample water pressure and outputs a control command to an automatic pressure reduction control unit so that the pressure becomes a set value, a manifold is provided in the outlet piping, and a part of the manifold is connected to a main stream from a part of the manifold. A pressure detector and a relief valve are connected to the manifold, and an electromagnetic on-off valve and an auxiliary flow rate adjustment valve are connected to the manifold. A bypass pipe is provided to communicate with and connect to the downstream side of the outlet pipe provided with the main flow regulating valve, and when the sample water pressure in the outlet pipe is reduced and the main/N, M regulating valves are shut off, the electromagnetic opening/closing is performed. It is characterized by providing a control means for opening the valve.

In the above-mentioned flow rate control mechanism, the control means for opening the electromagnetic on-off valve consists of a pressure detector provided in the manifold and a controller, the pressure detector detects the sample water pressure in the outlet piping, and the detected pressure value is The pressure reducing mechanism can be configured such that the controller outputs a valve opening command to the electromagnetic on-off valve when the pressure in the pressure reducing mechanism becomes lower than the minimum pressure reducing state.

[Effect]

According to the flow rate control mechanism of the 1RIIJ pressure reducing device according to the present invention, in the automatic pressure reducing device comprising a pressure reducing mechanism, an automatic pressure reducing control section, and a controller, a manifold is provided in the outlet piping led out from the pressure reducing mechanism, and from this manifold Reduced pressure sample water is supplied to the sample water analysis system through a main flow regulating valve, and in this case, a pressure detector and a relief valve are appropriately arranged on the manifold, and the main flow control valve is equipped with an electromagnetic on-off valve and an auxiliary flow regulating valve. By providing a bypass piping for the flow rate adjustment valve, when the source pressure of the high-pressure sample water in the inlet piping drops significantly and the pressure reduction mechanism no longer functions, this condition is detected by the pressure detector and the electromagnetic opening/closing is activated. Even when the valve is opened and the main flow rate adjustment valve is shut off due to the pressure reduction in the outlet pipe, a predetermined amount of sample water can be continuously supplied to the sample water analysis system via the bypass pipe.

〔Example〕

Next, embodiments of the flow rate control mechanism of the automatic pressure reducing device according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a system diagram of an automatic pressure reduction control system showing an embodiment of the flow rate control mechanism according to the present invention. For convenience of explanation, please refer to the fourth
Components that are the same as those of the conventional automatic pressure reduction control system shown in the figure are given the same reference numerals, and detailed explanation thereof will be omitted. 1st
In the figure, the pressure reduction mechanism 10 in this embodiment includes a pair of parallel pressure adjustment holes, and an inlet pipe for high-pressure sample water and an outlet pipe for reduced-pressure sample water are connected to one end of the pair of pressure adjustment holes, respectively. , a core wire for depressurization is inserted from the other end of the pressure adjustment hole so that the position thereof can be adjusted freely, and the pressure of the depressurized sample water in the outlet piping is maintained at a set value, As long as it has a configuration equivalent to that of the present invention, it can be effectively applied not only to the pressure reduction mechanism previously proposed by the applicant but also to conventional pressure reduction mechanisms.

The automatic pressure reduction control unit 12 is a mechanism configured to automatically adjust the insertion position of the pressure reduction core wire of the pressure reduction mechanism 10 by controlling an electric motor.

However, in this embodiment, the inlet pipe 16 and the outlet pipe 8 are connected to the connectors 14a and 14b, which communicate with the pressure adjustment hole of the pressure reducing mechanism 10, respectively, and the inlet pipe 16 has an inlet and an outlet pipe 8, respectively, which communicate with the pressure adjustment hole of the pressure reducing mechanism 10. An on-off valve 20 is provided. On the other hand, the outlet piping 18 is provided with a manifold 30 having a required volume, and the outlet piping 18 led out from a part of the manifold 30 is provided with a flow rate regulating valve 22 made of a needle valve.
The system is configured so that it communicates with the sample water analysis system. Also,
A relief valve 24 and a pressure detector 26 are connected to the manifold 30, respectively, and the structure is similar to that of a conventional automatic pressure reduction control system. That is, said pressure detection! The pressure signal detected at 26 is transferred to the controller 28, and the controller 28 compares the preset pressure setting value and the detected pressure value, calculates the deviation, and reduces the pressure in order to adjust the pressure according to this deviation. It is configured to send a control command for adjusting the movement of the core wire to the mechanism 10 to the automatic pressure reduction control section 12.

The configuration described above is basically the same as the configuration of the automatic pressure reduction control system in the conventional device. Therefore, in the present invention, the manifold 30 is provided in a part of the outlet piping 18 to simplify and downsize the connection structure of the complicated branching piping system, and the electromagnetic shut-off valve 32 and the needle can be connected from a part of the manifold 30. A bypass pipe 36 is provided which communicates with the outlet pipe 18 on the downstream side of the flow control valve 22 via an auxiliary flow control valve 34 consisting of a valve. In this case, the electromagnetic on-off valve 32 is configured to operate the sample water at the outlet pipe for one day when the sample water source pressure of the high-pressure sample water in the inlet pipe 16 is significantly reduced and the pressure reducing mechanism 10 is in the lowest pressure reducing state, that is, in a state where the pressure reducing mechanism is no longer functioning. When pressure is detected by the pressure detector 26, a valve opening command is sent to the electromagnetic on-off valve 32 via the controller 28, so that the valve is opened. Further, the auxiliary flow rate regulating valve 34 is constituted by a needle valve like the flow rate regulating valve 22 provided in the outlet pipe I8, but its operating pressure is set to a sufficiently low pressure. The bypass piping 36 configured in this way is
As mentioned above, when the source pressure of the high-pressure sample water in the inlet pipe 16 decreases significantly, the pipe automatically becomes open, and the flow rate adjustment valve 22 provided in the outlet pipe 18 becomes shut off due to the low pressure. Also, a predetermined amount of sample water can be continuously supplied to the analysis system.

FIG. 2 shows an example of a specific piping configuration of the manifold 30 and the bypass piping 36 in the outlet piping 18 shown in FIG. That is, in Figure 2,
This figure shows a case where the manifold 3o is arranged horizontally with respect to the operation panel P, and a connector 38 constituting the inlet of sample water is provided on one side of the manifold 3o, and a pressure detector is provided on the upper side of the manifold 30. 26, relief valve 24,
Electromagnetic on-off valves 32 are connected to each other, and an outlet pipe 18 is led out from the other side of the manifold 30 via a flow rate regulating valve 22. Further, a bypass pipe 36 is led out from one side of the electromagnetic on-off valve 32, and this bypass pipe 36 is connected to the manifold 3 via an auxiliary flow rate regulating valve 34.
The outlet piping 18 is connected to the downstream end 1.1) of the outlet pipe 18 led out from the outlet pipe 1.0 through a pipe joint 40. In addition,
Reference numeral 42 is a relief pipe section connected to the relief valve 24.

As described above, in the present invention, by providing the manifold 30 in a part of the outlet piping and connecting and arranging the control equipment and the bypass piping 36 to this manifold 30, the complicated piping configuration can be downsized and space can be saved. can do.

FIG. 3 shows another embodiment of the same piping configuration as FIG. 2. That is, FIG. 3 shows a case where the manifold 30 is arranged perpendicularly to the operation panel P. Similar to the embodiment shown in FIG. 2, this embodiment can also achieve a small and space-saving piping configuration. Therefore, the second
Components that are the same as those in the embodiment shown in the drawings are given the same reference numerals, and detailed explanation thereof will be omitted.

In the embodiment shown in FIGS. 2 and 3, the flow rate adjustment valve 22 and the auxiliary flow rate adjustment valve 34 are configured and arranged so that they can be adjusted on the operation panel P, respectively.
Efforts have been made to ensure that the conditions of the piping connected to these are appropriate.

〔Effect of the invention〕

As is clear from the embodiments described above, according to the present invention,
It has a pair of parallel pressure adjustment holes, and an inlet pipe for high-pressure sample water and an outlet pipe for reduced-pressure sample water are respectively connected to one end of the pair of pressure adjustment holes, and the pressure is reduced from the other end of the pressure adjustment hole. a pressure reduction mechanism formed by inserting a core wire; an automatic pressure reduction control unit that automatically controls the insertion position of the pressure reduction core wire with respect to the pressure adjustment hole; and a pressure reduction mechanism that detects the sample water pressure in the outlet piping and adjusts the pressure to a set value. In an automatic pressure reduction device equipped with a controller that outputs a control command to an automatic pressure reduction control unit so that By connecting the detector and relief valve, as well as providing a bypass piping to the main flow regulating valve via an electromagnetic on-off valve and an auxiliary flow regulating valve, a significant pressure reduction occurred in the inlet piping and the pressure reduction mechanism stopped functioning. Occasionally,
By automatically opening the electromagnetic on-off valve, the bypass piping is opened in place of the main flow adjustment valve, which is shut off to reduce pressure, and a predetermined amount of sample water is continuously supplied to the sample water analysis system. can be supplied.

The automatic opening/closing operation of the electromagnetic on-off valve is performed by detecting the sample water pressure in the outlet piping with a pressure detector installed in the manifold, and controlling the pressure reducing mechanism below the minimum reduced pressure state in the controller. If the controller outputs a valve opening command to the electromagnetic on-off valve, control operations can be performed easily and appropriately.

Further, according to the present invention, by providing a manifold in the outlet piping and connecting various control devices and piping, there is an advantage that a complicated configuration can be made compact and space-saving.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above (it goes without saying that various design changes can be made within the scope of the spirit of the present invention). be.

[Brief explanation of the drawing]

FIG. 1 is a control system diagram showing an embodiment of the flow rate control mechanism of an automatic pressure reducing device according to the present invention, and FIG. 2 is a piping configuration diagram showing an embodiment of the flow rate control mechanism that constitutes the control system shown in FIG. 1. 3 is a piping configuration diagram showing another embodiment of the flow rate control mechanism of the present invention, and FIG. 4 is a control system diagram showing an example of the configuration of the flow rate control mechanism of a conventional automatic pressure reducing device.

Claims (2)

[Claims] (1) It has a pair of parallel pressure adjustment holes, and an inlet pipe for high-pressure sample water and an outlet pipe for reduced-pressure sample water are respectively connected to one end of the pair of pressure adjustment holes, and the other end of the pressure adjustment hole a decompression mechanism including a decompression core wire inserted from the pressure adjustment hole; an automatic depressurization control part that automatically controls the insertion position of the decompression core wire with respect to the pressure adjustment hole; In an automatic depressurization device equipped with a controller that outputs a control command to an automatic depressurization control unit so that an outlet that leads out an outlet pipe communicating with the manifold, connects and arranges a pressure detector and a relief valve to the manifold, and further provides the main flow rate adjustment valve from a part of the manifold via an electromagnetic on-off valve and an auxiliary flow rate adjustment valve. A bypass pipe connected downstream of the pipe is provided, and a control means is provided to open the electromagnetic on-off valve when the sample water pressure in the outlet pipe is reduced and the main flow rate adjustment valve is shut off. Flow rate control mechanism of automatic pressure reducing device. (2) The control means for opening the electromagnetic on-off valve consists of a pressure detector provided in the manifold and a controller, the pressure detector detects the sample water pressure in the outlet piping, and this pressure detection value is used to reduce the pressure in the controller. 2. The flow rate control mechanism for an automatic pressure reducing device according to claim 1, wherein the controller outputs a valve opening command to the electromagnetic on-off valve when the pressure of the mechanism is lower than the minimum pressure reducing state.