JP2008089283A - Condition detection device for safety device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a condition detection device for a safety device capable of carrying out early correspondence/actions even when remotely monitoring movement by accurately and safely determining detection of presence or absence of operation of a safety valve or presence or absence of reseating without relying on senses of a person. <P>SOLUTION: The condition detection device is used in the safety device provided with a main steam pipe 4 carrying steam, the safety valve 6 opening when a pressure in the main stream pipe 4 reaches a predetermined value or more, and a discharge pipe 7 discharging steam flowing out from the main steam pipe 4 via the safety valve 6. It is provided with a first pressure detector 11 detecting the pressure in the main steam pipe 4, and a second pressure detector 12 detecting a pressure in the discharge pipe 7. On the basis of a difference P1-P2 between the pressure P1 detected by the first pressure detector 22 and the pressure P2 detected by the second pressure detector, presence or absence of operation of the safety valve 6 and presence or absence of stopping of steam, and an alarm responding to a determination result is generated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a state detection device for a safety device capable of detecting the operation of a safety valve provided in a main pipe through which a high-pressure working fluid flows, such as a main steam pipe of a power plant, and a blown-off state after the operation.

  In a boiler / turbine steam line system, steam generated in a boiler is guided to a steam turbine through a main steam pipe, and the turbine is rotated by the steam, thereby driving a generator to generate electric power. The main steam pipe is provided with a safety valve for escaping the main steam, and when the pressure of the main steam generated from the boiler becomes abnormal for some reason, the main steam is discharged to the atmosphere and other facilities. In addition, until the steam turbine is safely stopped in an emergency such as a system fault, steam is discharged to other equipment by a safety valve, and the inside of the main steam pipe is decompressed (see Patent Document 1).

JP 2001-263004 A

  However, in the conventional steam line system, the operation of the safety valve and the presence / absence of the steam blow-off after the operation are determined depending on the human senses. In other words, when the operator operates the safety valve, the operator can check for leak noise or touch the exhaust pipe of the safety valve with the hand to detect temperature changes, vibrations, etc. I was trying to do it.

  For this reason, it is not possible to accurately grasp when the safety valve is operating or when it has stopped blowing, especially in high-pressure and high-temperature steam piping, because steam blows out vigorously with noise during operation of the safety valve. Since there is danger, it is necessary to monitor trends from a distance, and there is an inconvenience that the response is delayed. Further, if the distance between the installation location of the safety valve and the operator is increased with the concentration of control, there is a disadvantage that it takes more time to confirm the operation of the safety valve and the blow-off.

  The present invention has been made in view of such circumstances, and it is possible to accurately and safely confirm the operation of the safety valve and the presence or absence of the blow-off by determining the presence or absence of the operation and the blow-off of the safety valve without depending on the human senses. The main object is to provide a state detection device for a safety device that can be performed, and can perform early countermeasures and measures even when monitoring trends from a remote location.

  To achieve the above object, a main pipe through which a working fluid flows, a safety valve opened when a pressure in the mother pipe reaches a predetermined value or more, and a working fluid that has flowed out of the main pipe through the safety valve are discharged. An operation state detection device for detecting an operation state of a safety device having a discharge pipe to be operated, a first pressure detection device for detecting a pressure in the mother pipe, and a second pressure detection for detecting a pressure in the discharge pipe And the presence or absence of operation of the safety valve and the working fluid from the discharge pipe based on the difference between the pressure detected by the first pressure detection device and the pressure detected by the second pressure detection device And a warning generating means for generating a warning corresponding to the determination result determined by the determination means. (Claim 1)

  Therefore, the presence / absence of the operation of the safety valve and the presence / absence of blocking of the working fluid from the discharge pipe are determined based on the pressure in the mother pipe detected by the first pressure detection device and the pressure in the discharge pipe detected by the second pressure detection device. Since it is determined based on the difference from the pressure, whether or not the safety valve is operating or whether or not the working fluid is blocked from the discharge pipe is automatically determined, and the operator must check the alarm generated from the alarm generation means. Thus, it is possible to grasp whether or not the safety valve is operating and whether or not the working fluid is blocked from the discharge pipe.

  Here, as a specific configuration example for determining the presence or absence of the operation of the safety valve by the determination unit, the determination unit is a predetermined set pressure value in which the pressure detected by the first pressure detection device is larger than the downflow pressure. The safety valve is opened when it is determined that the difference between the pressure detected by the first pressure detection device and the pressure detected by the second pressure detection device is equal to or less than the first predetermined value. Means for determining that the device has operated may be provided (claim 2).

  When the safety valve is opened and the high-pressure working fluid flows out from the mother pipe, the pressure in the mother pipe decreases and the difference between the pressure detected by the first pressure detector and the pressure detected by the second pressure detector is small. However, even when the system stops and the working fluid does not flow to the mother pipe, and the pressure in the mother pipe decreases, the pressure difference (the pressure detected by the first pressure detection device and the second pressure) In order to reliably determine that the pressure drop during operation of the system, that is, the safety valve has been activated during operation of the system, is less than the pressure detected by the detection device. It is preferable to add a condition that the pressure detected by the apparatus is equal to or greater than a predetermined set pressure value that is larger than the blow-down pressure.

  At this time, when the opening operation of the safety valve is determined, a self-holding means that holds the generation of an alarm corresponding thereto until it is determined that the working fluid is blown off may be provided. According to such a configuration, since the alarm is issued not only when the safety valve is operated by the self-holding means but also during the period when the safety valve is operating, it is easy to recognize the current state of the safety valve.

  Further, as a specific configuration example for determining whether or not the working fluid is blocked by the determination unit, the determination unit includes the pressure detected by the first pressure detection device after the opening operation of the safety valve is determined. When it is determined that the difference from the pressure detected by the second pressure detection device is greater than or equal to a second predetermined value that is greater than the first predetermined value, the working fluid is blown off. Means for determining may be provided (claim 4).

  When the pressure in the main steam pipe decreases and the safety valve is closed by its own restoring mechanism, the working fluid that has been blown up to now stops blowing, so the pressure detected by the first pressure detection device and the second pressure detection The difference from the pressure detected by the device increases. For this reason, when it is determined that the differential pressure is equal to or greater than the second predetermined value, it is determined that the working fluid is blowing off, and an alarm corresponding thereto is generated so that the operator can be in a state of blowing off. It becomes possible to grasp.

  In addition to the above configuration, the alarm generation means may output an alarm even when the pressure detected by the first pressure detection device is determined to be equal to or higher than the operating pressure value of the safety valve. Good (Claim 5).

  It is conceivable that the set pressure of the safety valve changes due to the use of the safety valve for many years, but in such a case, the presence or absence of the operation of the safety valve is determined with the predetermined operating pressure of the safety valve. It will not match the actual operation of the safety valve. For this reason, in the present invention, it is intended to detect the reliable operation of the safety valve using the pressure difference, but the preset operating pressure of the safety valve is a temporary guide for operating the safety valve. When the pressure in the mother pipe reaches or exceeds this operating pressure value, it is possible to predict the operation of the safety valve (to know the approximate timing at which the safety valve operates) by generating an alarm.

As described above, the presence / absence of the operation of the safety valve and the presence / absence of blocking of the working fluid from the discharge pipe are determined by the pressure detected by the first pressure detection device and the pressure detected by the second pressure detection device. Therefore, the operator can recognize the presence or absence of the operation of the safety valve and the presence or absence of blowing of the working fluid by recognizing the alarm generated by the alarm generation means. For this reason, it is no longer necessary to check the leak sound and exhaust pipe temperature during the operation of the safety valve with the five senses, and there is no risk of misidentification. It becomes possible to confirm.
Further, since the presence / absence of the operation of the safety valve and the presence / absence of the blow-off of the working fluid from the discharge pipe are automatically determined, even when the trend is monitored from a remote location, it is possible to respond quickly and take action.

  In particular, it is determined whether or not the safety valve is operating by the determination means, in which the pressure detected by the first pressure detection device is equal to or greater than a predetermined installation value that is greater than the blow-down pressure, and the first pressure detection device. If the means for determining that the safety valve has opened when it is determined that the difference between the detected pressure and the pressure detected by the second pressure detection device is equal to or less than the first predetermined value, It is possible to reliably determine that the safety valve is in a state in which the pressure increases. At this time, if it is determined that the opening operation of the safety valve is determined, a self-holding means that holds the generation of an alarm corresponding thereto until the blowing of the working fluid is determined is provided. Since the alarm is generated, the current state of the safety valve can be easily grasped.

  The determination means determines whether or not the working fluid is blocked by the pressure detected by the first pressure detection device and the pressure detected by the second pressure detection device after the opening operation of the safety valve is determined. If it is determined by means for determining that the working fluid is blown when it is determined that the difference is greater than or equal to a second predetermined value that is greater than the first predetermined value, the blowing after the safety valve is activated Can be determined accurately and easily.

  If an alarm is output even when the pressure in the mother pipe reaches the preset operating pressure of the safety valve, the operation of the safety valve can be predicted in addition to the above-described effects.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS The best embodiment of the present invention will be described below with reference to the accompanying drawings.

  In FIG. 1, the structural example which applied the state detection apparatus of the safety device which concerns on this invention to boiler-turbine steam line systems, such as a thermal power plant, is shown.

  The boiler / turbine steam line system 1 includes a boiler 2 and a main steam pipe (mother pipe) 4 that supplies steam from the boiler 2 to the turbine 3, and steam generated in the boiler 2 is supplied to the main steam pipe 4. The turbine 3 is guided through this, and the generator 3 is driven by rotating the turbine 3 with the steam to generate power.

  The safety device according to the present invention has a safety valve 6 that opens when the pressure in the main steam pipe rises above a predetermined value, and a discharge pipe 7 that discharges the steam that has flowed out through the safety valve 6, and the pressure in the main steam pipe The pressure in the main steam pipe 4 is released through the discharge pipe 7 when the pressure becomes a predetermined value or more.

  The main steam pipe 4 is provided with a first pressure detector 11 for detecting the internal pressure (main steam pipe internal pressure P1), and the exhaust pipe 7 is provided with the internal pressure (exhaust pipe internal pressure P2). A second pressure detector 12 to be detected is provided, and the main steam pipe pressure P1 detected by the first pressure detector 11 and the discharge pipe pressure P2 detected by the second pressure detector 12 are supplied to the control unit 13. Entered.

  In FIG. 2, the internal structure of the control unit 13 is shown. The control unit 13 inputs the main steam pipe pressure P1 from the first pressure detector 11, and determines whether or not the main steam pipe pressure P1 has reached the operating pressure value (A) of the safety valve 6 or more. Thus, when it is determined that P1 is equal to or greater than the operating pressure value (A), a first alarm generation command signal for generating an alarm (first alarm) based on the safety valve operating pressure value exceeding is provided in a remote control room or the like. The safety valve operating pressure value excess determination circuit 21 to be output to the alarm output device 14 (shown in FIG. 1) and the main steam pipe pressure P1 detected by the first pressure detector 11 are input, and the inside of the main steam pipe It is determined whether or not the pressure P1 is equal to or higher than the down pressure value (B), and when it is determined that P1 is equal to or higher than the down pressure value (B), a signal is sent to the input terminal of the AND circuit 22. Output blowdown pressure value excess determination circuit 23 and first pressure detector 1 is input, and it is determined whether or not the main steam pipe pressure P1 is equal to or higher than a predetermined set pressure value (C), and P1 is equal to or higher than a predetermined set pressure value (C). And a set pressure value excess determination circuit 24 that outputs a signal to the input terminal of the AND circuit 22 when it is determined that.

  Further, the main steam pipe internal pressure P1 detected by the first pressure detector 11 and the exhaust pipe internal pressure P2 detected by the second pressure detector 12 are inputted, and the main steam pipe internal pressure P1 and the exhaust pipe internal pressure P2 It is determined whether or not the difference (P1−P2) is equal to or less than a set pressure value (D) that can grasp that the safety valve 6 has operated, and P1−P2 is determined to be equal to or less than the set pressure value (D) A safety valve operation determination circuit 25 that outputs a safety valve operation confirmation signal in the case of

  The AND circuit 22 receives signals from the blow-down pressure value excess determination circuit 23 and the set pressure value excess determination circuit 24 and outputs an output signal to the AND circuit 27 when a condition according to the logical product is satisfied. I am doing so.

  A signal from the AND circuit 22 is input to an input terminal of the AND circuit 27, and a safety valve operation confirmation signal output from the safety valve operation determination circuit 25 is input. The AND circuit 27 has a condition according to a logical product. When the above is satisfied, an output signal is output to the input terminal of the OR circuit 28.

  In the OR circuit 28, when a condition according to the logical sum is satisfied, a second alarm generation command signal for generating an alarm (second alarm) based on the actual operation of the safety valve 6 is output to the alarm output device 14 and an AND described later. The alarm generation command signal is output to the circuit 29, and the output to the alarm output device 14 is held by a self-holding circuit 31 having a release circuit 30.

  Here, the blowing pressure value (B) refers to a difference between the blowing pressure and the blowing stop pressure, and is, for example, a pressure not more than 0.1 times the blowing pressure. The set pressure value (C) is a pressure value that is set to an arbitrary value that is higher than the blowing pressure value (B) and lower than the operating pressure value (A) of the safety valve 6. The reason for introducing such a down pressure value excess determination circuit 23 and a set pressure value excess determination circuit 24 is to grasp that the pressure in the main steam pipe has increased during the operation of the system. . That is, when the difference (P1-P2) between the main steam pipe pressure P1 and the discharge pipe pressure P2 becomes small, the system is stopped in addition to the case where the safety valve 6 is operated and the pressure in the main steam pipe is released. As a result, the differential pressure (P1-P2) may be reduced as a result, and as a result, the condition that P1 is equal to or greater than a predetermined set pressure value (C) greater than the down-flow pressure is added. This is to reliably capture the operation of the safety valve 6 during the operation of the system.

  Further, the control unit 13 inputs the main steam pipe pressure P1 detected by the first pressure detector 11 and the discharge pipe pressure P2 detected by the second pressure detector 12, and the main steam pipe pressure P1. Is close to the set pressure value at which the safety valve is closed and the steam has stopped blowing, for example, the pressure difference that occurs during normal operation of the system. It is determined whether or not the pressure is equal to or higher than a predetermined set value (E), and when it is determined that P1-P2 is equal to or higher than the set pressure value (E), the blow-off confirmation signal is output. A determination circuit 26 is provided.

  An alarm signal from the OR circuit 28 is added to the input terminal of the AND circuit 29, and an output signal from the blow-off determination circuit 26 is added. When the AND circuit 29 satisfies a condition according to a logical product, The third alarm generation command signal for generating an alarm based on the blow-off in the engine (third alarm) is output to the alarm output device 14, and the release signal is output to the release circuit 30. Shut off the output of the alarm generation command signal.

  The main steam pipe pressure P1 detected by the first pressure detector 11 and the discharge pipe pressure P2 detected by the second pressure detector 12 are respectively pressure display devices 15 (see FIG. 1) is always displayed.

  In the above circuit configuration, when the pressure in the main steam pipe becomes abnormally high for some reason, and the pressure in the main steam pipe reaches or exceeds the operating pressure value (A) of the safety valve 6, the alarm output device 14 is used. A first alarm is output. As a result, even when the actual operating pressure value of the safety valve 6 changes over time and the safety valve 6 is not actually operating, it is possible to recognize that the safety valve 6 is close to operating.

  The system is activated when the down pressure (B) exceeds the down pressure (B) by the down pressure determination circuit 23 and when the inside of the main steam pipe exceeds the predetermined set pressure value (C) by the set pressure value excess determination circuit 24. Is determined, and when it is determined that the differential pressure (P1-P2) is equal to or lower than the predetermined set value (D), it is determined that the safety valve 6 has actually been operated, and an alarm is issued. A second alarm is output via the output device 14. Therefore, the operator can grasp that the safety valve 6 has been operated (opened) by this second alarm.

  After that, when the pressure in the main steam pipe is released and the pressure in the main steam pipe is lowered, the safety valve 6 is closed and the high-pressure steam stops being ejected, the difference (P1) between the main steam pipe pressure P1 and the discharge pipe pressure P2 -P2) gradually increases. When it is determined that the differential pressure (P1-P2) is equal to or greater than a predetermined set value (E) that is close to the pressure difference generated during normal operation of the system, a third alarm is output. At the same time, the output state of the second alarm generation command signal held by the self-holding circuit 31 is reset, and the output of the second alarm is stopped.

  Therefore, the presence or absence of the operation of the safety valve 6 and the presence or absence of steam blowing from the discharge pipe 7 are determined by the pressure (P1) detected by the first pressure detector 11 and the pressure detected by the second pressure detector 12 ( Since it is detected based on the difference from P2), the presence / absence of the operation of the safety valve 6 and the presence / absence of the blowing of steam from the discharge pipe 7 are automatically determined, and the operator is generated from the alarm output device 14. By checking the alarm, it is possible to check whether the safety valve is operating and whether the steam is blown off, so you can check for leak noise or touch the exhaust pipe of the safety valve to detect temperature changes or vibrations. Therefore, it is possible to accurately and safely confirm whether the safety valve is operating and whether steam is blocked.

  In the state detection device described above, a configuration example in which a series of processing is performed by various circuits as the control unit 13 has been shown, but the above-described series of processing is similarly performed based on a predetermined program stored in a memory using a microcomputer. You may make it perform.

  That is, the control unit includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), an input / output port, a control circuit that controls a pressure display device and an alarm output device, The signals from the first pressure detector 11 and the second pressure detector 12 (main steam pipe pressure P1, discharge pipe pressure P2) are input, the input signal is processed according to a predetermined program given to the memory, and the pressure The display device 15 and the alarm output device 14 may be controlled.

  In FIG. 3, an example of a control operation in the case of processing using a program is shown as a flowchart. Hereinafter, the example of the control operation will be described based on the flowchart.

  The control unit 13 digitizes and inputs the main steam pipe pressure P1 detected by the first pressure detector 11 and the exhaust pipe pressure P2 detected by the second pressure detector 12 (step 50). Each pressure value is displayed on the pressure display device 15 on the basis of each pressure signal (step 52).

  Then, in step 54, it is determined whether or not the main steam pipe pressure P1 has reached a preset operating pressure value (A) of the safety valve 6 (step 54). In this step, when it is determined that the main steam pipe internal pressure P1 has reached the operating pressure value (A) or more, in order for the operator to recognize that the pressure is not abnormal even if the safety valve 6 originally operates, An alarm (first alarm) based on exceeding the operating pressure value of the safety valve 6 is output via the alarm output device 14 (step 56).

  Further, based on the main steam pipe internal pressure P1, it is determined whether or not the blowdown pressure value (B) or more has been reached (step 58). Based on the main steam pipe internal pressure P1, a predetermined set pressure value ( C) It is determined whether or not (step 60). If it is determined that the pressure is equal to or greater than the downflow pressure value (B) and equal to or greater than the predetermined set pressure value (C), the first pressure is determined. The difference (P1-P2) between the pressure P1 in the main steam pipe detected by the detector 11 and the pressure P2 in the discharge pipe detected by the second pressure detector 12 causes the safety valve 6 to operate to discharge steam from the main steam pipe 4. It is determined whether or not it is equal to or less than a set value (D) set as a value capable of recognizing the discharge through the tube 7 (step 62).

  And when it determines with P1-P2 being this setting value (D) or less, the alarm based on the actual operation | movement of a safety valve (2nd alarm) is output via the alarm output device 14 (step 64).

  Here, the preset blow-down pressure value (B) is set to a pressure set lower than the operating pressure value of the safety valve, for example, 10% or less of the operating pressure value (A) of the safety valve, as described above. The predetermined set pressure value (C) is a pressure value that is set to an arbitrary value that is higher than the blow-down pressure value (B) and lower than the operating pressure (A) of the safety valve. .

  Then, once the second alarm in step 64 is output, this state continues until the differential pressure (P1-P2) becomes equal to or higher than a predetermined set pressure value (E) close to the pressure difference generated during normal operation of the system. When the differential pressure (P1-P2) exceeds a predetermined set pressure value (E), the alarm (second alarm) based on the actual operation of the safety valve 6 is canceled (step 68), and at the same time, the safety valve 6 is closed, the steam stops blowing, and an alarm (third alarm) based on the blowing indicating that the system has returned to the normal state is output via the alarm output device 14 (step 70).

  Therefore, when the pressure in the main steam pipe reaches the preset operating pressure value of the safety valve, the first alarm is output, so the actual operating pressure value of the safety valve 6 changes over time, and the safety valve actually Even when it is not operating, it is possible to recognize that the safety valve 6 is close to operating.

  Then, it is determined that the system is in operation when the pressure in the main steam pipe is equal to or higher than the blowing pressure value (B) and equal to or higher than the predetermined installation pressure value (C). The difference (P1-P2) between the main steam pipe internal pressure P1 detected by the first pressure detector 11 and the exhaust pipe internal pressure P2 detected by the second pressure detector 12 is less than or equal to a predetermined set pressure value (D). If it is determined that the safety valve 6 is actually operated, it is determined that the safety valve 6 has actually been operated. Therefore, it is possible to accurately and safely grasp that the safety valve 6 has been operated during the operation of the system.

  Thereafter, when the safety valve 6 is closed and the steam from the discharge pipe 7 stops blowing, the main steam pipe internal pressure P1 detected by the first pressure detector 11 and the exhaust pipe internal pressure P2 detected by the second pressure detector 12. Since the difference (P1-P2) is larger than the predetermined pressure value (E) or higher, a third alarm is output to accurately and safely grasp the steam stoppage. It becomes possible.

  In the above configuration, the example of the configuration in which the state detection device of the safety device is applied to the boiler / turbine steam line system is shown. However, a substance capable of detecting pressure (liquid, gas, other poisonous deleterious substances, etc.) ) Applicable in all. For example, the above-described configuration has a mother pipe through which a working fluid such as oil flows, a safety valve that opens when the pressure in the mother pipe reaches a predetermined value or more, and a discharge that discharges the working fluid that has flowed out of the mother pipe through the safety valve. You may apply in order to confirm the operating state of the safety device provided with the pipe | tube.

FIG. 1 is a diagram showing a schematic configuration example in which a state detection device for a safety device according to the present invention is applied to a boiler / turbine steam line system. FIG. 2 is a block diagram illustrating a configuration example of the control unit of FIG. FIG. 3 is a flowchart showing an example of operation processing of the control unit of FIG.

Explanation of symbols

4 main steam pipe 6 safety valve 7 discharge pipe 11 first pressure detector 12 second pressure detector 13 control unit 14 alarm output device 15 pressure display device

Claims (5)

A safety pipe comprising a mother pipe through which a working fluid flows, a safety valve that opens when a pressure in the mother pipe reaches a predetermined value or more, and a discharge pipe that discharges the working fluid that has flowed out of the mother pipe through the safety valve. In the device for detecting the operating state of the device,
A first pressure detection device for detecting the pressure in the mother pipe, and a second pressure detection device for detecting the pressure in the discharge pipe,
Based on the difference between the pressure detected by the first pressure detection device and the pressure detected by the second pressure detection device, the presence or absence of operation of the safety valve and blowing of the working fluid discharged from the discharge pipe Determining means for determining the presence or absence of
And an alarm generation means for generating an alarm according to the determination result determined by the determination means. The determination means is configured such that the pressure detected by the first pressure detection device is equal to or greater than a predetermined set pressure value that is larger than the blowing pressure, and the pressure detected by the first pressure detection device and the pressure The apparatus further comprises means for determining that the safety valve has opened when it is determined that the difference from the pressure detected by the second pressure detection device is equal to or less than a first predetermined value. The operating state detection device of the safety device according to 1. 3. The safety device according to claim 2, further comprising a self-holding unit that holds an alarm corresponding to the opening of the safety valve until the working fluid is determined to be blown off when the opening operation of the safety valve is determined. Operating state detection device. The determination means determines whether the difference between the pressure detected by the first pressure detection device and the pressure detected by the second pressure detection device after the opening operation of the safety valve is determined is the first predetermined value. 3. The operating state of the safety device according to claim 2, further comprising means for determining that the working fluid is blown off when it is determined that the second predetermined value is greater than a second predetermined value. Detection device. The alarm generation means outputs an alarm even when it is determined that the pressure detected by the first pressure detection device is equal to or higher than an operating pressure value of the safety valve. Safety device operating state detection device.

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