JP3008620B2 - Stop and restart controllers for rotating machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stop control device for stopping an auxiliary machine such as a water injection pump after a rotary shaft of a rotary machine such as a vertical shaft pump has stopped, and a state where the stop of the rotary shaft has been confirmed. The present invention relates to a restart control device that restarts a rotary machine only by the above.

[0002]

2. Description of the Related Art Rotary machines such as vertical shaft pumps continue to rotate for a while due to inertia even when the drive voltage to the drive unit is cut off. Particularly in the idling state, it takes three to four and a half minutes to completely stop the rotating shaft. During rotation due to this inertia, the operation of auxiliary equipment such as a water injection pump for injecting lubricating water into the protective tube must be continued.

Conventionally, as shown in the flow chart of FIG. 4, when a stop operation is performed in a pump operating state to stop the driving of a driving machine connected to a rotating shaft (step 1), a timer means is provided. Starts a timing operation (step 2). When a predetermined time has elapsed (step 3), auxiliary equipment such as a water injection pump is stopped (step 4), and the stop operation is completed (step 5). In the case where a series of operations from the stop operation (step 1) to the completion of the stop (step 5) are arranged in a sequence, only after the completion of the stop (step 5), the starting operation of the rotating machine is performed. Some devices can be restarted.

[0004]

In the conventional stop control device for a rotary machine as described above, the time until the stop of the rotary shaft is predicted in advance and time is measured by a time measuring means. A considerably longer time than expected and actually required time is set as the predetermined time. For this,
The required stoppage time from the stop operation (Step 1) to the completion of the stop (Step 5) becomes longer. Therefore, in a device that cannot be restarted until a series of sequence operations until the stop is completed, there is a problem that a quick restart cannot be performed even in an emergency state.

[0005] Further, depending on the installation conditions of the rotating machine, the conditions of the connected piping, and the like, there is a possibility that the rotating shaft may be reversely rotated by a water flow or the like after stopping. However, in the conventional device,
In some cases, restart is performed in a state where the rotating shaft is rotating in the reverse direction, and an excessive starting torque is required for the driving machine, and there is a possibility that the device may be damaged.

SUMMARY OF THE INVENTION The present invention has been made in view of the circumstances of the above-described conventional apparatus, and has a stop control device for a rotary machine capable of shortening a required stop time, and a control method in a state where a rotary shaft is stopped. An object of the present invention is to provide a restart control device for a rotating machine that enables only a restart.

[0007]

In order to achieve the above object, a stop control means for a rotary machine according to the present invention is a means for interrupting a drive voltage of a drive of a rotary machine by a stop operation signal and immediately stopping the drive. Rotation stop detecting means for outputting a signal when the rotation axis is at a rotation speed of zero, stop confirmation means for outputting a stop confirmation signal when a signal from the rotation stop detection means continues for a predetermined time, The auxiliary machine attached to the rotary machine is stopped by a signal.

[0008] Further, according to the present invention, there is provided a restart control apparatus for a rotating machine, wherein the rotation stop detecting means outputs a signal when the rotating shaft of the rotating machine is at a zero rotation speed, and the signal from the rotation stop detecting means is provided for a predetermined time. Stop confirmation means for outputting a stop confirmation signal when continued, and control means for restarting the driving machine of the rotary machine when the presence of the stop confirmation signal can be confirmed when a start operation signal is given. Have been.

[0009]

The stop control device of the rotary machine detects the state of the rotating shaft at zero rotation, that is, the state where the rotating shaft is actually stopped by the rotation stop detecting means, and outputs a signal. When the signal is confirmed to continue for a predetermined time and a stop confirmation signal is output, the auxiliary machine is stopped by this signal. Therefore, after the driving machine is cut off the driving voltage and stopped, the auxiliary machine can be stopped slightly later than when the rotating shaft actually stops to complete the stopping operation. Therefore, the required stoppage time can be shortened as compared with the conventional one in which safety is largely expected. Further, if the rotating shaft is once stopped and then reversely rotated by a water flow or the like within a predetermined time, the auxiliary machine is not stopped.

[0010] The restarting device for the rotating machine restarts the driving machine of the rotating machine only when the control means confirms the presence of the stop confirmation signal when the starting operation for restarting is performed. Therefore, restarting is not performed in a state where the rotating shaft is rotating in the reverse direction due to a water flow or the like.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a vertical shaft pump as an embodiment to which a stop control device and a restart control device of a rotating machine according to the present invention are applied, and a block circuit diagram for controlling the same.
FIG. 3 is a flowchart illustrating the operation of the stop control device of FIG. 1, and FIG. 3 is a flowchart illustrating the operation of the restart control device of FIG.

First, in FIG. 1, reference numeral 10 denotes a vertical shaft pump as a rotary machine, and a protective tube 14 is disposed coaxially so as to cover the rotary shaft 12. In a gap between the protective tube 14 and the rotating shaft 12, a water injection pump 16 as an auxiliary machine is used.
Alternatively, lubricating water is injected through the water injection pipe 18 by the pressure of the discharge port of the vertical shaft pump 10 itself, and the underwater bearing is lubricated. A driving device 20 is provided at the upper end of the rotating shaft 12.
Are linked. In this drive unit 20, bearings and gears are appropriately incorporated, and an oil receiver is provided. Lubricating oil stored in the oil receiver is pumped out by a lubricating oil pump 36 as another auxiliary device, and the heat exchanger It is cooled at 38 and supplied to the drive unit 20 via the lubricating oil pipe 40. A rotation detecting gear 22 is provided at an intermediate portion of the rotating shaft 12. Pulse generating means 24 using a proximity switch, a photoelectric tube or the like is provided in correspondence with the rotation detecting gear 22, and the number of pulses corresponding to the number of rotations of the rotating shaft 12 is given to the time measuring means 26. As the timer means 26, for example, a timer circuit which is cleared each time a pulse is received and outputs a signal if the signal is not cleared for a predetermined time, or a charging / discharging circuit having a certain time constant is discharged each time a pulse is received to charge a charging voltage. May be configured to output a signal from the comparator when no pulse is received for a predetermined time by comparing whether or not the voltage exceeds a reference voltage with a comparator. May be converted to a voltage value, and a comparator may be used to determine whether the converted voltage has dropped below the reference voltage. Note that a rotation stop detecting means is formed by the pulse generating means 24 and the time measuring means 26.

The signal output from the timer means 26 when the number of rotations of the rotating shaft 12 becomes substantially zero and no pulse is received for a predetermined time or more is output to the second timer means 28.
Is given to the logic means 30. The second timing means 28
When a signal is given from the time counting means 26, a time counting operation is started, and when a lapse of a second predetermined time is timed, a signal is given to the logic means 30. The logic means 30 comprises a second timekeeping means 28
A signal from the rotation stop detecting means, that is, an AND circuit for confirming the presence of the signal from the time counting means 26 when the signal is output from the control means. 32 and accessory control means 34. Here, it is assumed that the signal from the rotation stop detecting means is continuously output while the rotation speed of the rotating shaft 12 is kept zero. Further, the second timer means 28 and the logic means 30 form stop confirmation means.

The control means 30 is further provided with a start operation signal and a stop operation signal. Then, the drive voltage of the driving machine 20 is immediately cut off by the stop operation signal. Also, in response to the start operation signal after the operation has been stopped once,
The logical product of this start operation signal and the stop confirmation signal from the stop confirmation means is obtained by an AND circuit or the like, and when the start operation signal is given, only when the presence of the stop confirmation signal can be confirmed, the drive 20 Is supplied with a drive voltage. This supply state of the drive voltage is held by a suitable self-holding circuit or the like until a stop operation signal is given.

The accessory control means 34 drives the water injection pump 16 and the lubricating oil pump 36 when the drive voltage is supplied to the drive unit 20 by the start operation signal. The auxiliary machine control means 34 maintains the driving state of the water injection pump 16 and the lubricating oil pump 36 by an appropriate self-holding circuit and the like, and drives the water injection pump 16 and the lubricating oil pump 36 by the stop confirmation signal from the stop confirmation means. Cut off the voltage.

In such a configuration, the stop control device operates as described below with reference to FIG. First,
In a pump operating state in which the drive unit 20, the water injection pump 16 and the lubricating oil pump 36 are driven, a stop operation is performed to stop the drive of the drive unit 20 (step 1). After that, when the rotation speed of the rotating shaft 12 is detected as zero and a signal is output from the rotation stop detecting means (step 2), the second time measuring means 28 starts the time measuring operation (step 3). Further, when a predetermined time which can confirm the rotation stop of the rotating shaft 12 has elapsed (step 4), the presence of the signal from the rotation stop detecting means is confirmed again, that is, the continuation of the rotation speed of the rotating shaft 12 is confirmed to be zero. (Step 5), the water injection pump 16 and the lubricating oil pump 36 as the auxiliary machines are stopped (Step 6), the stop operation is completed (Step 7), and a restartable state is set. If the rotation shaft 12 is not rotated to zero by the reverse rotation of the rotating shaft 12 due to a water flow or the like before the predetermined time is measured by the second timer 28, the process returns to step 2 and the injection pump 16 and the lubricating oil pump 36 are stopped. Not done.

In such an operation, the timekeeping operation by the second timekeeping means 28 for confirming the rotation stop of the rotating shaft 12 is started from the time when the rotation shaft 12 actually stops rotating. Do not need. For this reason,
The time is significantly shorter than the predetermined time of the timekeeping means which is set with a great expectation of safety. Therefore,
The stop control device of the present invention can significantly shorten the required stop time as compared with the conventional device. In addition, before the stop operation is completed, if the rotating shaft 12 is reversely rotated by a water flow or the like, the water injection pump 16 and the lubricating oil pump 3
Since the driving of No. 6 is not stopped, damage due to lack of lubricating water and lack of lubricating oil does not occur.

Further, the restart control device operates as described below with reference to FIG. When the start operation of the drive unit 20 is performed in the restartable state after the stop operation is completed (step 8), the control unit 32 confirms the presence of the stop confirmation signal output from the stop confirmation unit (step 9). ). Here, if the stop confirmation signal exists,
The drive voltage is supplied to the drive unit 20 (step 10), and the pump 20 is brought into the operation state. If there is no stop confirmation signal in step 9, the rotary shaft 12 may be reversely rotated by the water flow or the like, and the pump operation is not restarted without the drive voltage being supplied to the drive unit 20.

In such an operation, when the rotation speed of the rotating shaft 12 cannot be confirmed to be zero and there is a possibility that the rotating shaft 12 is rotated in the reverse direction, the driving machine 20 is not restarted, and an excessive starting torque is required. It does not cause damage to the equipment.

In the above embodiment, the vertical shaft pump 10 has been described as a rotary machine. However, the present invention is not limited to this, and is useful for a rotary machine having a large inertial force such as a flywheel pump or a high-speed short-stage blower. is there. Further, the device of the present invention is suitable for a control device of a precedence standby type operation pump in which operation and stop are frequently performed. Further, the rotation stop detecting means, the stop confirming means, and the control means are not limited to the structure of the above-described embodiment, but may be of any structure as long as a desired action can be obtained.

[0021]

As described above, since the stop control device and the restart control device of the rotating machine according to the present invention are constituted, the following special effects can be obtained.

The stop control device for the rotary machine detects that the rotary shaft has actually stopped, and after a short period of time elapses, the auxiliary machine is stopped. The time can be reduced compared to conventional devices. In addition, if the rotating shaft is rotated backward by a water flow or the like within a predetermined time after the rotating shaft is once stopped, the auxiliary machine will not be stopped, and there will be no damage due to lack of lubricating water or the like.

In the restart control device for a rotating machine, when the rotating shaft is not rotated and the rotating shaft is not stopped, the rotating machine is not restarted even if the starting operation is performed, and the drive by the excessive starting torque is performed. The machine will not be damaged. As a result, the maintenance work can be omitted and the durable life of the entire apparatus can be extended.

[Brief description of the drawings]

FIG. 1 is a vertical axis pump as an embodiment to which a stop control device and a restart control device of a rotary machine according to the present invention are applied, and a block circuit diagram for controlling the vertical pump.

FIG. 2 is a flowchart illustrating an operation of the stop control device of FIG. 1;

FIG. 3 is a flowchart illustrating an operation of the restart control device of FIG. 1;

FIG. 4 is a flowchart illustrating the operation of a conventional stop control device for a rotary machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vertical axis pump 12 Rotary axis 16 Water injection pump 20 Drive 24 Pulse generating means 26 Clocking means 28 Second clocking means 30 Logic means 32 Control means 34 Auxiliary equipment control means 36 Lubricating oil pump

Claims (6)

(57) [Claims] 1. A means for interrupting a drive voltage of a rotary machine in response to a stop operation signal and immediately stopping the drive, a rotation stop detecting means for outputting a signal when the rotation axis is at a rotation speed of zero, and a rotation stop detection means. A rotation confirmation unit that outputs a stop confirmation signal when a signal from the stop detection unit continues for a predetermined time, and an auxiliary device attached to the rotary machine is stopped by the stop confirmation signal. Machine stop control device. 2. A stop control apparatus for a rotary machine according to claim 1, wherein said rotation stop detecting means outputs a pulse at a cycle corresponding to a rotation speed of a rotating shaft, and said pulse is output for a predetermined time or more. A stop control device for a rotating machine, comprising: a timing unit that outputs a signal when the rotation is not performed. 3. The stop control device for a rotary machine according to claim 1, wherein said stop confirmation means starts time operation by a signal from said rotation stop detection means, and said second time measurement means. Logic means for confirming the presence of a signal from the rotation stop detecting means when a predetermined time has elapsed by the means. 4. The stop control device for a rotary machine according to claim 1, wherein the auxiliary machine is a water injection pump for injecting lubricating water into a protection tube. 5. The stop control device for a rotary machine according to claim 1, wherein the auxiliary device is a lubricating oil pump that supplies lubricating oil to bearings and gears of the driving device. Control device. 6. A rotation stop detecting means for outputting a signal when the rotation axis of the rotary machine is at a rotation speed of zero, and a stop confirmation for outputting a stop confirmation signal when a signal from the rotation stop detecting means continues for a predetermined time. And a control means for restarting the driving machine of the rotating machine when the presence of the stop confirmation signal can be confirmed when the start operation signal is given. Startup control device.