CN113267991A - Boiler MFT protection system and method thereof - Google Patents

Boiler MFT protection system and method thereof Download PDF

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Publication number
CN113267991A
CN113267991A CN202110392477.9A CN202110392477A CN113267991A CN 113267991 A CN113267991 A CN 113267991A CN 202110392477 A CN202110392477 A CN 202110392477A CN 113267991 A CN113267991 A CN 113267991A
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China
Prior art keywords
mft
relay
intermediate output
signal
output relay
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CN202110392477.9A
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Chinese (zh)
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马浩
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Shanghai Shidongkou First Power Plant of Huaneng Power International Inc
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Shanghai Shidongkou First Power Plant of Huaneng Power International Inc
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Priority to CN202110392477.9A priority Critical patent/CN113267991A/en
Publication of CN113267991A publication Critical patent/CN113267991A/en
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    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B9/00—Safety arrangements
    • G05B9/02—Safety arrangements electric
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/327—Testing of circuit interrupters, switches or circuit-breakers
    • G01R31/3277—Testing of circuit interrupters, switches or circuit-breakers of low voltage devices, e.g. domestic or industrial devices, such as motor protections, relays, rotation switches
    • G01R31/3278—Testing of circuit interrupters, switches or circuit-breakers of low voltage devices, e.g. domestic or industrial devices, such as motor protections, relays, rotation switches of relays, solenoids or reed switches

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

The invention relates to a boiler MFT protection system and method, the system includes signal receiving unit, signal reset unit, signal output unit and signal monitoring unit, the signal receiving unit is connected in parallel by three routes of input relay loops and made up, each input relay loop is connected in series by two MFT conditional action relay normally closed nodes and an intermediate output relay and made up, when there is no MFT action condition normally, the node of two MFT conditional action relays is the disconnect state, the intermediate output relay is the power-off state, does not act; when the FSSS outputs an MFT protection action instruction, nodes of the two MFT conditional action relays are both in a conducting state, and the intermediate output relay is in a power-on state and acts; the signal monitoring unit is used for monitoring whether the state of the intermediate output relay is in failure. Compared with the prior art, the method can effectively solve the problems of error output of the relay loop and failure of the MFT relay, and can timely and reliably find whether the intermediate output relay breaks down or not.

Description

Boiler MFT protection system and method thereof
Technical Field
The invention relates to the technical field of thermal power generation boiler protection control, in particular to a boiler MFT protection system and a boiler MFT protection method.
Background
In a thermal power plant, a boiler Furnace Safety monitoring System (FSSS) is an important guarantee for safe operation of a boiler and a unit. The FSSS logic needs to monitor various Main FUEL TRIP (MFT) conditions and if either condition is met, the FSSS logic triggers the MFT relay loop action. Because all MFT conditions can cause serious damage to equipment and human bodies, once a certain MFT condition is met, the FSSS immediately stops all combustors and powder making equipment until the MFT condition disappears and an oil leakage test is completed, and the MFT is tripped to allow reset after the boiler is purged. However, in the actual use process, the MFT itself relay may be triggered by a fault, or the MFT relay may be rejected due to the existence of the MFT condition.
A conventional MFT protection system is shown in fig. 1, and includes:
(1) a signal receiving unit: the system is composed of three relay loops, each loop is formed by connecting an input relay (MFT conditional action relay) normally open node and an intermediate output relay (R relay) in series, under the condition of normal (when no MFT action condition exists), the MFT conditional action relay is not electrified, the node is in a disconnected state, the output relay R is in a power-off state, and the output relay R does not act; when the FSSS system sends an MFT conditional action instruction, the MFT conditional action relay is electrified, the node is in a conducting state, the output relay R is in an electrified state, and the output relay R acts.
(2) A signal reset unit: the system comprises an MFT reset switch normally closed node, an auxiliary contact of an R relay and the R relay, wherein when an input relay (MFT conditional action relay) normally open node of a signal receiving loop is closed, the MFT reset switch normally closed node of a signal reset unit, the auxiliary contact of the R relay and the R relay form a self-locking loop; when the input relay (MFT conditional action relay) node of the signal receiving loop is disconnected, the latching loop still keeps outputting, and when the MFT reset switch node is disconnected, the self-latching loop is disconnected, and the R relay does not output any more.
(3) A signal output unit: in the relay expansion unit, when any two or more of the relays R1, R2, and R3 are operated, the relays R21, R22, R23, and R24 are operated and output to the boiler system equipment and other related equipment.
In the above conventional MFT protection system, when the MFT action 1 relay or the contact fails, R1 may act, and if there is a failure in one of the R2 or R3 relays at this time, the relay circuit may erroneously output;
when the FSSS system is in power failure, the boiler system needs MFT action to trip boiler system equipment and other system related equipment, but 3 relays such as MFT action 1, 2 and 3 and the like do not act after the FSSS is in power failure in the structure, so that the MFT relay loop does not output and refuses to act.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a boiler MFT protection system and a method thereof so as to solve the problems of wrong output of a relay loop and refusal of an MFT relay.
The purpose of the invention can be realized by the following technical scheme: a boiler MFT protection system comprises a signal receiving unit, a signal resetting unit, a signal output unit and a signal monitoring unit, wherein the signal receiving unit is formed by connecting three input relay loops in parallel, each input relay loop is formed by connecting two MFT condition action relay normally-closed nodes and an intermediate output relay in series, when the MFT condition does not exist normally, the nodes of the two MFT condition action relays are in an off state, the intermediate output relay is in a power-off state, and the intermediate output relay does not act;
when the FSSS outputs an MFT protection action instruction, nodes of the two MFT conditional action relays are both in a conducting state, and the intermediate output relay is in a power-on state and acts;
the signal monitoring unit is used for monitoring whether the state of the intermediate output relay has a fault or not.
Further, the signal reset unit is formed by connecting an MFT reset switch normally-closed node, an auxiliary contact of an intermediate output relay and a corresponding intermediate output relay in series, and when the MFT condition action relay node of the signal receiving unit is closed, the MFT reset switch normally-closed node of the signal reset unit, the auxiliary contact of the intermediate output relay and the corresponding intermediate output relay form a self-locking loop;
when the MFT conditional action relay node of the signal receiving unit is disconnected, the self-locking loop still keeps outputting, and when the MFT reset switch node is disconnected, the self-locking loop is disconnected, and the intermediate output relay does not output any more.
Furthermore, the signal output unit is formed by connecting three output relay loops in parallel, each output relay loop is formed by connecting two intermediate output relays in series, the three output relay loops are connected to the equipment relay loop together, the equipment relay loop is formed by connecting different equipment relays in parallel, and when any more than two intermediate output relays act, the equipment relay is triggered to act.
Further, the signal monitoring unit is disposed in a DCS (Distributed Control System).
A boiler MFT protection method comprises the following steps:
s1, the signal receiving unit acquires an MFT protection action instruction from the FSSS, and changes the working states of two MFT conditional action relays and an intermediate output relay in the input relay loop according to the MFT protection action instruction;
s2, according to the MFT condition in the signal receiving unit, the signal resetting unit changes the working state of the intermediate output relay;
s3, according to the working state of the intermediate output relay, the signal output unit correspondingly changes the working state of the equipment relay;
and S4, acquiring the current MFT condition, and monitoring whether the intermediate output relay breaks down in real time by the signal monitoring unit in combination with the working state of the intermediate output relay.
Further, the specific process of step S1 is as follows: when the MFT action condition does not exist normally, the FSSS does not send an MFT condition action instruction, the MFT condition action relay is powered on, the node is in a disconnected state, the intermediate output relay is in a power-off state, and the intermediate output relay does not act;
when the FSSS sends an MFT conditional action instruction, the MFT conditional action relay loses power, the node is in a conducting state, the intermediate output relay becomes a power-on state, and the intermediate output relay acts.
Further, the specific process of step S2 is as follows: when the MFT conditional action relay node of the signal receiving unit is closed, the signal resetting unit forms a self-locking loop;
when the MFT conditional action relay node of the signal receiving unit is disconnected, the self-locking loop still keeps outputting, at the moment, the MFT reset switch node of the signal resetting unit is disconnected, the self-locking loop is disconnected, and the intermediate output relay does not output any more.
Further, the specific process of step S3 is as follows: when any more than two intermediate output relays act, all the equipment relays of the signal output unit act.
Further, the step S4 specifically includes the following steps:
s41, the signal monitoring unit compares the working states of all the intermediate output relays, if the working states of all the intermediate output relays are consistent, the current intermediate output relay is judged not to have a fault, otherwise, the step S42 is executed;
and S42, acquiring the current MFT condition to determine the theoretical working state of the intermediate output relay, sequentially comparing the working states of all the intermediate output relays with the theoretical working state, if the working states are consistent, indicating that the intermediate output relay is not in fault, otherwise indicating that the intermediate output relay is in fault.
Further, the specific process of determining the theoretical operating state of the intermediate output relay in step S42 is as follows: when the normal MFT-free condition exists, the theoretical working state of the intermediate output relay is off;
in the presence of the MFT condition, the theoretical operating state of the intermediate output relay is on.
Compared with the prior art, the invention has the following advantages:
the invention sets two series MFT condition action relay normally closed nodes in each input relay loop of a signal receiving unit, when an MFT action 1 relay or a contact fails, an intermediate output relay can not act because an MFT action 2 relay is connected in series, if one intermediate output relay fails, the input relay loop can not output by mistake, thereby effectively preventing the input signal from malfunctioning when the input signal fails, and an MFT protection device can not malfunction; in addition, when the FSSS loses power, the nodes of the MFT action 1 relay and the MFT action 2 relay are conducted, all the intermediate output relays act, the MFT protection relay loop outputs normally, and therefore the condition that the MFT refuses to operate when the FSSS loses power is avoided.
The invention can monitor the working states of all the intermediate output relays by combining the current MFT condition through arranging the signal monitoring unit, can timely and reliably monitor which intermediate output relay has a fault, and further avoids the error output phenomenon of a relay loop.
Drawings
FIG. 1 is a schematic structural diagram of a conventional boiler MFT protection system;
FIG. 2 is a schematic structural view of the boiler MFT protection system of the present invention;
FIG. 3 is a schematic flow chart of a boiler MFT protection method of the present invention.
Detailed Description
The invention is described in detail below with reference to the figures and specific embodiments.
Examples
As shown in fig. 2, a boiler MFT protection system comprises a signal receiving unit, a signal resetting unit, a signal output unit and a signal monitoring unit, wherein the signal receiving unit is formed by connecting three input relay loops in parallel, each input relay loop is formed by connecting two MFT conditional action relay normally-closed nodes in series with an intermediate output relay, when no MFT action condition is normal, the nodes of the two MFT conditional action relays are both in an off state, the intermediate output relay is in a power-off state, and the intermediate output relay does not act;
when the FSSS outputs an MFT protection action command, the nodes of the two MFT conditional action relays are both in a conducting state, the intermediate output relay is in a power-on state, and the intermediate output relay acts.
The signal reset unit is formed by connecting an MFT reset switch normally closed node, an auxiliary contact of an intermediate output relay and a corresponding intermediate output relay in series, and when the MFT conditional action relay node of the signal receiving unit is closed, the MFT reset switch normally closed node of the signal reset unit, the auxiliary contact of the intermediate output relay and the corresponding intermediate output relay form a self-locking loop;
when the MFT conditional action relay node of the signal receiving unit is disconnected, the self-locking loop still keeps outputting, and when the MFT reset switch node is disconnected, the self-locking loop is disconnected, and the intermediate output relay does not output any more.
The signal output unit is formed by connecting three output relay loops in parallel, each output relay loop is formed by connecting two intermediate output relays in series, the three output relay loops are connected to the equipment relay loop together, the equipment relay loop is formed by connecting different equipment relays in parallel, and when any more than two intermediate output relays act, the equipment relay is triggered to act.
The signal monitoring unit is used for monitoring whether the state of the intermediate output relay fails, and in the embodiment, the signal monitoring unit is arranged in the DCS.
The above boiler MFT system is applied to practice, and its specific operation process is shown in fig. 3, and includes the following steps:
s1, the signal receiving unit obtains the MFT protection operation instruction from the FSSS, and changes the operating states of the two MFT conditional operation relays and the intermediate output relay in the input relay loop according to the MFT protection operation instruction, specifically:
when the MFT action condition does not exist normally, the FSSS does not send an MFT condition action instruction, the MFT condition action relay is powered on, the node is in a disconnected state, the intermediate output relay is in a power-off state, and the intermediate output relay does not act;
when the FSSS sends an MFT conditional action instruction, the MFT conditional action relay loses power, the node is in a conducting state, the intermediate output relay becomes a power-on state, and the intermediate output relay acts;
s2, operating the working state of the relay according to the MFT condition in the signal receiving unit, and the signal resetting unit correspondingly changes the working state of the intermediate output relay, specifically: when the MFT conditional action relay node of the signal receiving unit is closed, the signal resetting unit forms a self-locking loop;
when the MFT conditional action relay node of the signal receiving unit is disconnected, the self-locking loop still keeps outputting, at the moment, the MFT reset switch node of the signal resetting unit is disconnected, the self-locking loop is disconnected, and the intermediate output relay does not output any more;
s3, according to the working state of the intermediate output relay, the signal output unit correspondingly changes the working state of the equipment relay, specifically: when any more than two intermediate output relays act, all equipment relays of the signal output unit act;
s4, acquiring the current MFT condition, and monitoring whether the intermediate output relay breaks down in real time by the signal monitoring unit by combining the working state of the intermediate output relay, specifically:
firstly, the signal monitoring unit compares the working states of all the intermediate output relays, and if the working states of all the intermediate output relays are consistent, the current intermediate output relay is judged not to have a fault;
otherwise, acquiring the current MFT condition to determine the theoretical working state of the intermediate output relay: when the normal MFT-free condition exists, the theoretical working state of the intermediate output relay is off;
when the MFT condition exists, the theoretical working state of the intermediate output relay is on;
and then sequentially comparing the working states of all the intermediate output relays with the theoretical working state, if the working states are consistent, indicating that the intermediate output relay is not in fault, otherwise indicating that the intermediate output relay is in fault.
In fig. 2, MFT actions 1-6 are normally closed node MFT conditional action relays, R1-R3 are intermediate output relays, and R21-R24 are different device relays, wherein the signal receiving unit is composed of three relay loops, each loop is formed by connecting two input relay (MFT conditional action relays) normally closed nodes and an intermediate output relay (R relay) in series. Under the normal condition (when no MFT action condition exists), the nodes of the two MFT condition action relays are both in an off state, the output relay is in a power-off state, and the output relay does not act. After the FSSS system sends an MFT protection action instruction, the nodes of the two MFT conditional action relays are both in a conducting state, the output relay is in a power-on state, and the output relay R acts.
The signal reset unit consists of an MFT reset switch normally-closed node, an auxiliary contact of the R relay and the R relay. When an input relay (MFT conditional action relay) normally-open node of the signal receiving loop is closed, an MFT reset switch normally-closed node of the signal reset unit, an auxiliary contact of the R relay and the R relay form a self-locking loop; when the input relay (MFT conditional action relay) node of the signal receiving loop is disconnected, the latching loop still keeps outputting, and when the MFT reset switch node is disconnected, the self-latching loop is disconnected, and the R relay does not output any more.
The signal output unit is a relay expansion unit, and when any two or more relays among R1, R2 and R3 are operated, the relays such as R21, R22, R23 and R24 are operated and output to the relevant equipment of a boiler system and other systems.
The signal monitoring unit compares the operating states of the R1, R2 and R3, all the states of the R1, R2 and R3 are off in normal conditions, and all the states of the R1, R2 and R3 are on when the MFT condition operation relay is closed, and if the signal monitoring unit compares the states of the R1, R2 and R3 and finds that the states of the three relays of the R1, R2 and R3 are not consistent, the signal monitoring unit determines that one of the relays of the R1, R2 and R3 is not in a corresponding state, and compares the state with whether the MFT condition is satisfied, thereby determining which of the R relays has a problem.
In summary, the present invention can effectively prevent the MFT protection device from malfunction when the input signal fails: when the MFT action 1 relay or the contact has a fault, the R1 cannot act due to the fact that the MFT action 2 relay is connected in series, and if one of the R2 or R3 relay has a fault at the moment, the relay loop cannot output in error;
when the FSSS system loses power, the MFT refuses to operate: when the FSSS is powered off, the nodes of the MFT action 1 relay and the MFT action 2 relay are switched on, the R1 relay acts, and similarly, the R2 and the R3 act, and the MFT protection relay loop outputs normally;
the state monitoring of R1, R2, R3 relay can be to discovering in time whether the relay breaks down the problem.

Claims (10)

1. A boiler MFT protection system comprises a signal receiving unit, a signal resetting unit, a signal output unit and a signal monitoring unit, and is characterized in that the signal receiving unit is formed by connecting three input relay loops in parallel, each input relay loop is formed by connecting two MFT condition action relay normally-closed nodes and an intermediate output relay in series, when the MFT condition does not exist normally, the nodes of the two MFT condition action relays are both in an off state, the intermediate output relay is in a power-off state, and the intermediate output relay does not act;
when the FSSS outputs an MFT protection action instruction, nodes of the two MFT conditional action relays are both in a conducting state, and the intermediate output relay is in a power-on state and acts;
the signal monitoring unit is used for monitoring whether the state of the intermediate output relay has a fault or not.
2. The boiler MFT protection system according to claim 1, wherein said signal reset unit is comprised of a MFT reset switch normally closed node, an auxiliary contact of an intermediate output relay and a corresponding intermediate output relay in series, wherein when the MFT conditional action relay node of the signal receiving unit is closed, the MFT reset switch normally closed node of the signal reset unit and the auxiliary contact of the intermediate output relay and the corresponding intermediate output relay form a self-locking loop;
when the MFT conditional action relay node of the signal receiving unit is disconnected, the self-locking loop still keeps outputting, and when the MFT reset switch node is disconnected, the self-locking loop is disconnected, and the intermediate output relay does not output any more.
3. The boiler MFT protection system according to claim 1, wherein said signal output unit comprises three output relay circuits connected in parallel, each output relay circuit comprising two intermediate output relays connected in series, said three output relay circuits being commonly connected to an equipment relay circuit comprising different equipment relays connected in parallel, wherein when any two or more intermediate output relays are activated, the equipment relay is activated.
4. The boiler MFT protection system of claim 1, wherein the signal monitoring unit is disposed in the DCS.
5. A method of protecting MFT of a boiler using the system of claim 1, comprising the steps of:
s1, the signal receiving unit acquires an MFT protection action instruction from the FSSS, and changes the working states of two MFT conditional action relays and an intermediate output relay in the input relay loop according to the MFT protection action instruction;
s2, according to the MFT condition in the signal receiving unit, the signal resetting unit changes the working state of the intermediate output relay;
s3, according to the working state of the intermediate output relay, the signal output unit correspondingly changes the working state of the equipment relay;
and S4, acquiring the current MFT condition, and monitoring whether the intermediate output relay breaks down in real time by the signal monitoring unit in combination with the working state of the intermediate output relay.
6. The boiler MFT protection method as claimed in claim 5, wherein said step S1 is specifically performed by: when the MFT action condition does not exist normally, the FSSS does not send an MFT condition action instruction, the MFT condition action relay is powered on, the node is in a disconnected state, the intermediate output relay is in a power-off state, and the intermediate output relay does not act;
when the FSSS sends an MFT conditional action instruction, the MFT conditional action relay loses power, the node is in a conducting state, the intermediate output relay becomes a power-on state, and the intermediate output relay acts.
7. The boiler MFT protection method as claimed in claim 5, wherein said step S2 is specifically performed by: when the MFT conditional action relay node of the signal receiving unit is closed, the signal resetting unit forms a self-locking loop;
when the MFT conditional action relay node of the signal receiving unit is disconnected, the self-locking loop still keeps outputting, at the moment, the MFT reset switch node of the signal resetting unit is disconnected, the self-locking loop is disconnected, and the intermediate output relay does not output any more.
8. The boiler MFT protection method as claimed in claim 5, wherein said step S3 is specifically performed by: when any more than two intermediate output relays act, all the equipment relays of the signal output unit act.
9. The boiler MFT protection method as claimed in claim 5, wherein said step S4 specifically comprises the steps of:
s41, the signal monitoring unit compares the working states of all the intermediate output relays, if the working states of all the intermediate output relays are consistent, the current intermediate output relay is judged not to have a fault, otherwise, the step S42 is executed;
and S42, acquiring the current MFT condition to determine the theoretical working state of the intermediate output relay, sequentially comparing the working states of all the intermediate output relays with the theoretical working state, if the working states are consistent, indicating that the intermediate output relay is not in fault, otherwise indicating that the intermediate output relay is in fault.
10. The boiler MFT protection method as claimed in claim 9, wherein said step S42 of determining the theoretical operating state of the intermediate output relay comprises the specific steps of: when the normal MFT-free condition exists, the theoretical working state of the intermediate output relay is off;
in the presence of the MFT condition, the theoretical operating state of the intermediate output relay is on.
CN202110392477.9A 2021-04-13 2021-04-13 Boiler MFT protection system and method thereof Pending CN113267991A (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201829929U (en) * 2010-10-11 2011-05-11 靳允立 Novel hard trip loop for large-scale thermal power unit MFT (main fuel trip)
CN206759035U (en) * 2017-06-01 2017-12-15 中国神华能源股份有限公司 Circuit and device for protection equipment
CN210345425U (en) * 2019-07-24 2020-04-17 陕西华电榆横煤电有限责任公司榆横发电厂 Boiler MFT trip gear
CN211530736U (en) * 2020-04-10 2020-09-18 山东电力工程咨询院有限公司 Boiler tripping control circuit and system
CN212435343U (en) * 2020-06-05 2021-01-29 济南中能电力工程有限公司 Boiler MFT tripping protection system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201829929U (en) * 2010-10-11 2011-05-11 靳允立 Novel hard trip loop for large-scale thermal power unit MFT (main fuel trip)
CN206759035U (en) * 2017-06-01 2017-12-15 中国神华能源股份有限公司 Circuit and device for protection equipment
CN210345425U (en) * 2019-07-24 2020-04-17 陕西华电榆横煤电有限责任公司榆横发电厂 Boiler MFT trip gear
CN211530736U (en) * 2020-04-10 2020-09-18 山东电力工程咨询院有限公司 Boiler tripping control circuit and system
CN212435343U (en) * 2020-06-05 2021-01-29 济南中能电力工程有限公司 Boiler MFT tripping protection system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
李忠生: "MFT软逻辑及硬回路设计", 《科技视界》 *

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