JP2009204246A - Control device and control method for refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device and a control method for a refrigerator in which unnecessary trip stop is avoided. <P>SOLUTION: The control device 20 for the refrigerator 10 includes a means for determining whether or not a refrigeration system 1 having the refrigerator 10 has an abnormality; a means for determining whether or not voltage of a power source 71 supplying electric power to the refrigerator 10 drops after the abnormality is determined and while operation of the refrigerator 10 is continued; and a means for performing trip stop of the refrigerator 10 when it is determined that the voltage of the power source does not drop. The control device prevents trip stop of the refrigerator 10 when an abnormality caused by drop in voltage is detected prior to detection of the voltage drop of the power source 71. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device and a control method for a refrigerator.

  When the freezer is used in a clean room of a semiconductor factory, if the freezer is tripped due to a power failure, it takes time to restart, which adversely affects product yield and the like. It is important to avoid unnecessary trip stops of the refrigerator. This is particularly important in areas where the voltage of commercial power supply is unstable.

  Patent Document 1 discloses an operating device for a refrigeration apparatus that can be easily restarted even if an instantaneous power failure occurs. When an abnormal operation that continues for a certain period of time occurs during the operation of the refrigeration unit, the operation unit enters a trip state and stops the operation of the refrigeration unit. When the refrigeration unit is restarted, the trip state is released and then started. Perform the action. The driving device performs only the starting operation when restarting after a normal stop. The driving device includes an instantaneous power failure detection unit and a control unit. The instantaneous power failure detection means detects an instantaneous power failure of the refrigeration apparatus. In response to the output from the instantaneous power failure detection means, the control means detects whether or not there is a stopped device in the refrigeration apparatus, and if there is a stopped device, it is close to a normal stop within a time less than the predetermined time. Stop operation.

Japanese Patent No. 3172607

  The objective of this invention is providing the control apparatus and control method of a refrigerator with which an unnecessary trip stop is avoided.

  Hereinafter, means for solving the problem will be described using the numbers used in (Best Mode for Carrying Out the Invention). These numbers are added to clarify the correspondence between the description of (Claims) and (Best Mode for Carrying Out the Invention). However, these numbers should not be used to interpret the technical scope of the invention described in (Claims).

  A control device for a refrigerator according to the present invention includes a means for determining presence / absence of abnormality in a refrigeration system (1) provided with a refrigerator (10), and the operation of the refrigerator after it is determined that the abnormality is present. Means for determining whether or not there is a voltage drop in the power supply (71) that supplies power to the refrigerator, and when it is determined that there is no voltage drop in the power supply, the refrigerator is tripped Means.

  The refrigerator includes a compressor (11) and an electric motor (15) that drives the compressor. A contactor (22) is provided between the electric motor and the power source. The contactor includes a coil (22b) and is closed only when a current flows through the coil. A relay (23) is provided between the coil and the power source. The relay is closed only when the contactor-on command signal (80) is output. The control device stops the output of the contactor on command signal when it is determined that the contactor is opened and closed, and when the contactor is determined to be open and closed when it is determined that there is a voltage drop of the power supply. It is preferable to further comprise means.

  When it is determined that there is a voltage drop in the power supply, the control device periodically determines whether the voltage drop in the power supply has been recovered, and that the voltage drop in the power supply has been recovered. When it is determined within a predetermined time after it is determined that there is a voltage drop, a means for determining whether the abnormality has been recovered, and the refrigerator is normally stopped when it is determined that the abnormality has not been recovered It is preferable to further comprise means for continuing the operation of the refrigerator when it is determined that the abnormality has been recovered. The restart of the refrigerator that has been tripped requires human operation. The above-described operation is not required for restarting the refrigerator that is normally stopped.

  When it is determined that there is a voltage drop in the power supply, the control device periodically determines whether the voltage drop in the power supply has been recovered, and that the voltage drop in the power supply has been recovered. It is preferable to further comprise means for normally stopping the refrigerator when it is not determined within a predetermined time after it is determined that there is a voltage drop. The restart of the refrigerator that has been tripped requires human operation. The above-described operation is not required for restarting the refrigerator that is normally stopped.

  The method for controlling a refrigerator according to the present invention includes a step of determining whether there is an abnormality in the refrigeration system (1) including the refrigerator (10), and after determining that there is an abnormality, and operating the refrigerator And determining whether or not there is a voltage drop in the power supply (71) that supplies power to the refrigerator. When it is determined that there is no voltage drop of the power supply, the refrigerator is tripped.

  The refrigerator includes a compressor (11) and an electric motor (15) that drives the compressor. A contactor (22) is provided between the electric motor and the power source. The contactor includes a coil (22b) and is closed only when a current flows through the coil. A relay (23) is provided between the coil and the power source. The relay is closed only when the contactor-on command signal (80) is output. In the control method, when it is determined that there is a voltage drop of the power supply, the step of determining opening / closing of the contactor and the output of the contactor on command signal are stopped when it is determined that the contactor is open. It is preferable to further comprise a step.

  In the control method, when it is determined that the voltage drop of the power source is present, the step of periodically determining whether the voltage drop of the power source is recovered, and the fact that the voltage drop of the power source is recovered It is preferable that the method further includes a step of determining whether the abnormality has been recovered when it is determined within a predetermined time after it is determined that there is a voltage drop. When it is determined that the abnormality has not recovered, the refrigerator is normally stopped. When it is determined that the abnormality has been recovered, the operation of the refrigerator is continued. The restart of the refrigerator that has been tripped requires human operation. The above-described operation is not required for restarting the refrigerator that is normally stopped.

  In the control method, when it is determined that the voltage drop of the power source is present, the step of periodically determining whether the voltage drop of the power source is recovered, and the fact that the voltage drop of the power source is recovered Preferably, the method further includes a step of normally stopping the refrigerator when it is not determined within a predetermined time after it is determined that there is a voltage drop. The restart of the refrigerator that has been tripped requires human operation. The above-described operation is not required for restarting the refrigerator that is normally stopped.

  ADVANTAGE OF THE INVENTION According to this invention, the control apparatus and control method of a refrigerator which avoid an unnecessary trip stop are provided.

  With reference to the accompanying drawings, the best mode for carrying out a control device and a control method for a refrigerator according to the present invention will be described below.

(First embodiment)
FIG. 1 shows a refrigeration system 1 according to a first embodiment of the present invention. The refrigeration system 1 includes a refrigerator 10, a control device 20, a transformer 21, a contactor 22, a relay 23, a voltage drop detection circuit 30, a cooling water circulation system 50, a contactor 52, and a cold water circulation system 60. Prepare. The refrigerator 10 is a turbo refrigerator, and includes a compressor 11, a condenser 12, an expansion valve 13, an evaporator 14, and an electric motor 15 that drives the compressor 11. The refrigerant discharged from the compressor 11 passes through the condenser 12, the expansion valve 13, and the evaporator 14 in order and returns to the compressor 11. The cooling water circulation system 50 includes a cooling water pump 51 that circulates cooling water for cooling the refrigerant in the condenser 12. The cooling water pump 51 is connected to the commercial power supply 71 via the contactor 52. The cold water circulation system 60 includes a cold water pump 61 that circulates cold water cooled by the refrigerant in the evaporator 14. Each of the cooling water pump 51 and the cold water pump 61 is supplied with electric power from a commercial power supply 71.

  Each of control device 20 and voltage drop detection circuit 30 is connected to commercial power supply 71 via transformer 21. A contactor 22 is provided between the electric motor 15 and the commercial power supply 71. The contactor 22 includes a contact 22a and a coil 22b. Only when the current flows through the coil 22b, the contactor 22 is closed, and the contact 22a connects the electric motor 15 to the commercial power source 71. A transformer 21 and a relay 23 are provided between the coil 22b and the commercial power supply 71. The commercial system power supply 71, the transformer 21, the relay 23, and the coil 22b are connected in series in this order. The relay 23 includes a contact 23a and a coil 23b. The control device 20 outputs a contactor-on command signal (current) 80 to the coil 23b. Only when the contactor-on command signal 80 is output, the relay 23 is closed, and the contact 23 a connects the coil 22 b to the commercial power supply 71 through the transformer 21. Therefore, the contactor 22 is closed and power is supplied from the commercial system power supply 71 to the electric motor 15 only when the contactor-on command signal 80 is output and the voltage of the commercial system power supply 71 is sufficiently high. When the control device 20 stops operating due to a power failure, the output of the contactor-on command signal 80 is stopped, so the motor 15 is stopped.

  Referring to FIG. 2, refrigeration system 1 includes abnormality detection circuits 31 to 33 and abnormality detection circuits 41 to 43 in addition to voltage drop detection circuit 30 described above. The voltage drop detection circuit 30 monitors the voltage of the commercial system power supply 71 upstream of the contactor 22 and detects the voltage drop of the commercial system power supply 71. The abnormality detection circuit 31 detects that the temperature of the electric motor 15 is high. The abnormality detection circuit 32 detects an interlock abnormality of the cold water pump 61. The abnormality detection circuit 33 detects an interlock abnormality of the cooling water pump 51. The abnormality detection circuit 41 detects that the temperature of the lubricating oil in the compressor 11 is high. The abnormality detection circuit 42 detects that the temperature in the inverter panel (not shown) that controls the electric motor 15 is high. The abnormality detection circuit 43 detects an overcurrent of an oil pump (not shown) that circulates the lubricating oil of the compressor 11. The abnormality monitored in the refrigeration system 1 is not limited to this, and is described here with some examples.

  The temperature of the electric motor 15 is high, the interlock abnormality of the chilled water pump 61, and the interlock abnormality of the cooling water pump 51 are caused by the voltage drop of the commercial system power supply 71, and the voltage of the commercial system power supply 71 This is an abnormality that may be detected before a decrease is detected, and is called abnormality 1. The voltage drop of the commercial power supply 71 is also called abnormality 1. Each of the high temperature of the lubricating oil, the high temperature in the inverter panel, and the overcurrent of the oil pump is an abnormality that is not abnormality 1, and is called abnormality 2. Abnormality 1 and abnormality 2 are abnormalities in the refrigeration system 1. Each of the voltage drop detection circuit 30, the abnormality detection circuits 31 to 33, and the abnormality detection circuits 41 to 43 outputs a signal indicating a corresponding abnormality detection state to the control device 20.

  The control device 20 is realized as a computer that operates based on a software program, for example. The control device 20 determines the presence / absence of abnormality and the recovery (recovery) of the abnormality based on each signal. As necessary, the control device 20 includes an operation start signal 81 as a control signal for starting the operation of the refrigerator 10, a normal stop signal 82 as a control signal for normally stopping the refrigerator 10, and a refrigerator. A trip stop signal 83 is output as a control signal for tripping 10. The restart of the refrigerator 10 that has been tripped requires a resetting operation by a person. The restart of the refrigerator 10 that is normally stopped does not require a resetting operation by a person.

  When abnormality 2 occurs, the refrigerator 10 needs to be tripped immediately. On the other hand, when the voltage of the commercial power supply 71 is reduced and the temperature of the electric motor 15 is high, the interlocking abnormality of the cooling water pump 61 and the interlocking abnormality of the cooling water pump 51 occur due to this, the refrigerator immediately 10 does not have to stop tripping. In order to restart the refrigerator 10 that has stopped tripping, it is necessary to perform a resetting operation by a person, and it takes time. Therefore, it is necessary to avoid unnecessary trip stopping.

  With reference to FIG. 3, the control method of the refrigerator 10 which concerns on this embodiment is equipped with step S1-S14. In the figure, an arrow indicating the timing of the control cycle is shown. The timing of the control cycle corresponds to the boundary between a certain control cycle and the next control cycle.

(Step S1)
In step S <b> 1, the control device 20 outputs an operation start signal 81 and outputs a contactor on command signal 80 in order to start the operation of the refrigerator 10. Thereafter, the control device 20 continues to output the contactor on command signal 80 unless otherwise specified. After step S1, the process proceeds to step S2.

(Steps S2 to S4)
In steps S2 to S4 for forming a loop, the refrigerator 10 is normally operated. Step S2 is the beginning of the loop, and step S4 is the end of the loop. In step S <b> 3, the control device 20 determines the presence / absence of an abnormality based on signals from the voltage drop detection circuit 30, the abnormality detection circuits 31 to 33, and the abnormality detection circuits 41 to 43. When it is determined that there is no abnormality, the normal operation of the refrigerator 10 is continued. That is, the normal operation of the refrigerator 10 is continued until it is determined that there is some abnormality, and the determination in step S3 is periodically performed.

(Step S5)
When it is determined in step S3 that there is an abnormality 2, the control device 20 outputs a trip stop signal 83 to stop the trip of the refrigerator 10 and stops the output of the contactor on command signal 80.

(Steps S6 and S7)
In step S3, when it is determined that there is no abnormality 2 and it is determined that abnormality 1 is present, the control device 20 continues to operate the refrigerator 10 (step S6), and the voltage of the commercial power supply 71 decreases. Is determined (step S7). In the control cycle next to the control cycle in which the determination in step S3 is performed, the determination in step S7 is performed.

(Step S15)
When it is determined in step S7 that there is no voltage drop of the commercial power supply 71, the control device 20 outputs a trip stop signal 83 to stop the trip of the refrigerator 10 and stops the output of the contactor on command signal 80. . When it is determined that there is no voltage drop of the commercial power supply 71, the abnormality 1 determined to be present in step S3 is considered to have occurred due to a cause other than the instantaneous voltage drop, so the refrigerator 10 needs to be tripped and stopped. is there.

(Steps S8 to S11)
If it is determined in step S7 that there is a voltage drop in the commercial power supply 71, the control device 20 continues the operation of the refrigerator 10 in steps S8 to S11 that form a loop. Step S8 is the beginning of the loop, and step S11 is the end of the loop. In step S9, the control device 20 determines whether or not the voltage drop of the commercial system power supply 71 has been recovered (recovered). When it is determined that the voltage drop of the commercial system power supply 71 has not been recovered (recovered), the control device 20 continues the voltage drop duration of the commercial system power supply 71 (after determining that there is a voltage drop of the commercial system power supply 71). It is determined whether or not the current time is shorter than a predetermined time (example: 2 seconds) (step S10). In step S10, when it is determined that the duration of the voltage drop of the commercial power supply 71 is shorter than the predetermined time, the operation of the refrigerator 10 is continued. That is, as long as it is determined in step S9 that the voltage drop of the commercial system power supply 71 has not been recovered (recovered) and it is determined in step S10 that the duration of the voltage drop of the commercial system power supply 71 is shorter than the predetermined time. The operation of the refrigerator 10 is continued, and the determinations in steps S9 and S10 are periodically performed.

(Step S12)
When it is determined in step S9 that the voltage drop of the commercial system power supply 71 has been recovered (recovered), that is, the voltage drop of the commercial system power supply 71 within a predetermined time after it is determined that there is a voltage drop of the commercial system power supply 71. Is determined to have recovered (recovered), the voltage drop of the commercial power supply 71 is considered to be an instantaneous voltage drop. In this case, the control device 20 determines whether or not the abnormality 1 determined to be detected in step S3 has been recovered (recovered) (step S12). When it is determined that the abnormality 1 has been recovered (recovered), the refrigeration system 1 returns to the normal operation in steps S2 to S4. In the control cycle next to the control cycle in which the determination in step S9 is performed, the determination in step S12 is performed.

(Step S13)
When it is determined in step S10 that the duration of the voltage drop of the commercial power supply 71 is not shorter than the predetermined time, and in step S12, the abnormality 1 has not been recovered (recovered) (the abnormality 1 is continuing). If it is determined, the process proceeds to step S13. Here, when the duration of the voltage drop of the commercial power supply 71 is not shorter than a predetermined time, it is considered that the voltage drop of the commercial power supply 71 is not an instantaneous voltage drop but a power failure. In step S <b> 13, the control device 20 outputs the normal stop signal 82 to stop the refrigerator 10 normally, and stops the output of the contactor on command signal 80. As a result, the compressor 11 stops. When the process proceeds from step S10 to step S13, the voltage drop of the commercial power supply 71 is recovered (recovered), and after the abnormality 1 determined to be present in step S3 is recovered (recovered), the process proceeds to step S14. When the process proceeds from step S12 to step S13, after abnormality 1 is recovered (recovered), the process proceeds to step S14.

(Step S14)
In step S14, the control device 20 automatically performs a restart process of the refrigerator 10. Here, the control device 20 outputs an operation start signal 81 and restarts the contactor on command signal 80 in order to restart the refrigerator 10. After step S14, the refrigeration system 1 returns to the normal operation of steps S2 to S4.

  According to this embodiment, the trip stop of the refrigerator 10 caused by the instantaneous voltage drop of the commercial system power supply 71 is avoided regardless of the order of the detection of the abnormality 1 and the detection of the voltage drop of the commercial system power supply 71.

  In the present embodiment, the trip stop of the refrigerator 10 is avoided if it is determined that there is a voltage drop of the commercial system power supply 71 in the control cycle next to the control cycle in which it is determined that the abnormality 1 is present. According to the present embodiment, there is no need for a high-performance voltage drop detection circuit that can detect a voltage drop of the commercial power supply 71 in a short time from its occurrence.

  Note that the timing of the control cycle is not limited to that shown in FIG.

(Second Embodiment)
In the refrigeration system 1 described above, when the voltage drop of the commercial power supply 71 occurs, the contactor 22 may open even when the control device 20 is outputting the contactor on command signal 80. In this case, when the voltage drop of the commercial power supply 71 is immediately restored (recovered), the contactor 22 is closed and an excessive load is applied to the motor 15. As a result, the electric motor 15 may be damaged. The control method of the refrigerator 10 according to the second embodiment of the present invention can solve such a problem.

  With reference to FIG. 3, the control method of the refrigerator 10 which concerns on this embodiment is demonstrated. In the control method of the refrigerator 10 according to the present embodiment, the following operation is added to the control method of the refrigerator 10 according to the first embodiment. The control device 20 monitors the open / closed state of the contactor 22.

(Step S6)
When it is determined in step S3 that there is a voltage drop of the commercial power supply 71, the controller 20 determines whether the contactor 22 is opened or closed in subsequent step S6. If it is determined that the contactor 22 is open, the process proceeds to step S13. If it is determined that the contactor 22 is closed, the process proceeds to step S7.

(Step S8)
If it is determined in step S7 that there is a voltage drop in the commercial power supply 71, the controller 20 determines whether the contactor 22 is opened or closed in the subsequent step S8. If it is determined that the contactor 22 is open, the process proceeds to step S13. If it is determined that the contactor 22 is closed, the process proceeds to step S9.

(Step S11)
When it is determined in step S10 that the duration of the voltage drop of the commercial power supply 71 is shorter than the predetermined time, the controller 20 determines whether the contactor 22 is opened or closed in subsequent step S11. When it is determined that the contactor 22 is open, the process proceeds to step S13, and when it is determined that the contactor 22 is closed, the process proceeds to step S8.

  According to this embodiment, the electric motor 15 is prevented from being damaged, and the refrigerator 10 is safely stopped.

FIG. 1 shows a refrigeration system according to a first embodiment of the present invention. FIG. 2 shows the inputs and outputs of the control device provided in the refrigeration system. FIG. 3 is a flowchart of the control method of the refrigerator according to the first embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Refrigeration system 10 ... Refrigerator 11 ... Compressor 12 ... Condenser 13 ... Expansion valve 14 ... Evaporator 15 ... Electric motor 20 ... Control device 21 ... Transformer 22 ... Contactor 22a ... Contact 22b ... Coil 23 ... Relay 23a ... Contact 23b ... Coil 30 ... Voltage drop detection circuits 31-33, 41-43 ... Abnormality detection circuit 50 ... Cooling water circulation system 51 ... Cooling water pump 52 ... Contactor 60 ... Cold water circulation system 61 ... Cold water pump 71 ... Commercial power supply 80 ... Contactor ON command signal 81 ... operation start signal 82 ... normal stop signal 83 ... trip stop signal

Claims (10)

Means for determining the presence or absence of an abnormality in a refrigeration system equipped with a refrigerator;
Means for determining the presence or absence of a voltage drop of a power source that supplies power to the refrigerator after the abnormality is determined and while the operation of the refrigerator is continued;
Means for stopping tripping of the refrigerator when it is determined that there is no voltage drop of the power supply. The refrigerator includes a compressor and an electric motor that drives the compressor,
A contactor is provided between the electric motor and the power source;
The contactor includes a coil and is closed only when current flows through the coil;
A relay is provided between the coil and the power source;
The relay is closed only when the contactor on command signal is output,
When it is determined that there is a voltage drop of the power supply, means for determining whether to open or close the contactor;
The control device for a refrigerator according to claim 1, further comprising means for stopping output of the contactor on command signal when it is determined that the contactor is open. When it is determined that there is a voltage drop of the power supply, means for periodically determining whether the voltage drop of the power supply has been recovered;
Means for determining whether or not the abnormality has been recovered when it is determined within a predetermined time that the voltage drop of the power source has been recovered from the determination that the voltage drop of the power source is present;
Means for normally stopping the refrigerator when it is determined that the abnormality has not been recovered, and means for continuing the operation of the refrigerator when it is determined that the abnormality has been recovered;
Restarting the refrigerator that has been tripped requires human intervention,
The refrigerating machine control device according to claim 2, wherein the operation of the refrigerating machine normally stopped does not require the operation. When it is determined that there is a voltage drop of the power supply, means for periodically determining whether the voltage drop of the power supply has been recovered;
A means for normally stopping the refrigerator when it is not determined within a predetermined time after it has been determined that the power supply voltage drop has occurred, and that the power supply voltage drop has been recovered;
Restarting the refrigerator that has been tripped requires human intervention,
The refrigerating machine control device according to claim 2, wherein the operation of the refrigerating machine normally stopped does not require the operation. When it is determined that there is a voltage drop of the power supply, means for periodically determining whether the voltage drop of the power supply has been recovered;
Means for determining whether or not the abnormality has been recovered when it is determined within a predetermined time that the voltage drop of the power source has been recovered from the determination that the voltage drop of the power source is present;
Means for normally stopping the refrigerator when it is determined that the abnormality has not been recovered, and means for continuing the operation of the refrigerator when it is determined that the abnormality has been recovered;
Restarting the refrigerator that has been tripped requires human intervention,
The refrigerating machine control device according to claim 1, wherein the operation of the refrigerating machine that is normally stopped does not require the operation. When it is determined that there is a voltage drop of the power supply, means for periodically determining whether the voltage drop of the power supply has been recovered;
A means for normally stopping the refrigerator when it is not determined within a predetermined time after it has been determined that the power supply voltage drop has occurred, and that the power supply voltage drop has been recovered;
Restarting the refrigerator that has been tripped requires human intervention,
The refrigerating machine control device according to claim 1, wherein the operation of the refrigerating machine that is normally stopped does not require the operation. Determining whether there is an abnormality in a refrigeration system including a refrigerator; and
Determining whether there is a voltage drop in a power source that supplies power to the refrigerator after the abnormality is determined and while the operation of the refrigerator continues.
The refrigerator control method in which the refrigerator is tripped when it is determined that there is no voltage drop of the power source. The refrigerator includes a compressor and an electric motor that drives the compressor,
A contactor is provided between the electric motor and the power source;
The contactor includes a coil and is closed only when current flows through the coil;
A relay is provided between the coil and the power source;
The relay is closed only when the contactor on command signal is output,
If it is determined that there is a voltage drop of the power supply, the step of determining the opening and closing of the contactor;
The method for controlling a refrigerator according to claim 7, further comprising a step of stopping output of the contactor-on command signal when it is determined that the contactor is open. If it is determined that there is a voltage drop of the power supply, periodically determining whether the voltage drop of the power supply has been recovered;
A step of determining whether or not the abnormality has been recovered when it is determined within a predetermined time after it has been determined that the power supply voltage drop has occurred, and that the power supply voltage drop has been recovered;
When it is determined that the abnormality has not recovered, the refrigerator is normally stopped,
When it is determined that the abnormality has been recovered, the operation of the refrigerator is continued,
Restarting the refrigerator that has been tripped requires human intervention,
The method for controlling a refrigerator according to claim 7 or 8, wherein the operation of the refrigerator that is normally stopped does not require the operation. If it is determined that there is a voltage drop of the power supply, periodically determining whether the voltage drop of the power supply has been recovered;
A step of normally stopping the refrigerator when it is not determined within a predetermined time after it has been determined that the power supply voltage drop has been recovered, and
Restarting the refrigerator that has been tripped requires human intervention,
The method for controlling a refrigerator according to claim 7 or 8, wherein the operation of the refrigerator that is normally stopped does not require the operation.

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