JP5363929B2 - Steam supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent abnormal stop of steam use parts due to decline in steam supply amount and steam pressure and to prevent decline in quality of products manufactured by the steam use parts when the steam supply amount is lowered by full blow performed by boilers in the state where an allowance of the steam supply amount is small with respect to a steam use amount. <P>SOLUTION: In the steam supply system comprising the boilers 1 generating steam by heating water and the steam use parts 2 using the steam generated by the boilers 1, when the full blow for discharging boiler water within the boiler 1 is performed by stopping combustion of the boiler 1, output of an informing signal for informing beforehand implementation of the full blow is started at the point before start of the full blow. Based on the informing signal, the steam use amount by the steam use parts 2 is reduced before implementation of the full blow, and then, the full blow is started. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a steam supply system including a boiler that generates steam by heating water and a steam using unit that uses steam generated by the boiler.

  In a boiler that generates steam by heating water, impurities in the water gradually concentrate by repeating water supply and evaporation. For this purpose, it is necessary to periodically carry out all blows for discharging sludge accumulated in the can. Of course, in a boiler that is performing all blows, combustion is stopped and steam cannot be supplied. Therefore, in a multi-can installation where multiple boilers are installed, all blowers must be blown so that they do not overlap. The timing is being adjusted. However, even if all blows do not overlap, when there is a boiler that performs all blows, the amount of steam that can be supplied to the entire boiler is reduced compared to the normal time.

  If the steam supply amount in the boiler is small relative to the steam usage amount in the steam use section, if the steam supply amount decreases due to the full blow of the boiler, the steam supply amount falls below the steam usage amount, May be insufficient. If the steam pressure drops due to a shortage of steam supply, the operation of the steam using part cannot be maintained and the steam using part stops abnormally or the operation of the steam using part is incomplete. In some cases, the quality of the product manufactured in the steam use section is deteriorated. If this happens, it will affect a wide range.

JP-A-3-36403

  The problem to be solved by the present invention is that the steam supply amount and the steam pressure are reduced when the steam supply amount decreases due to a full blow of the boiler in a state where the steam supply amount is less than the steam use amount. The purpose is to prevent the steam using part from being abnormally stopped due to the lowering and the quality of the product manufactured by the steam using part from being deteriorated.

  The invention according to claim 1 is a steam supply system comprising a boiler that generates steam by heating water and a steam using part that uses the steam generated in the boiler, and stops the combustion of the boiler. When performing all blows to discharge the can water, start the output of a notification signal to notify the implementation of all blows in advance before the start of all blows, and perform all blows based on the notification signal It is characterized in that the amount of steam used in the steam using section is reduced before, and then all blows are started.

  According to a second aspect of the present invention, in the steam supply system, output of a notification signal for notifying execution of all blows is continued until a time after the end of all blows, and all blows are finished. However, while the notification signal is being output, the steam use amount is continuously reduced in the steam use portion, and the steam use amount reduction in the steam use portion is ended after the signal for performing all blows is finished. It is characterized by being.

  Even if the steam supply amount is reduced at the time of performing all blows by outputting a notification signal for performing all blows before the start of all blows and reducing the amount of steam used in advance based on the notification signals, It is possible to prevent all the steam using parts from stopping abnormally and the operation of the steam using parts from being incomplete. In addition, even after the completion of all blows, steam supply cannot be performed until the internal pressure of the boiler that has performed all blows reaches the specified pressure. After the boiler that had been able to supply steam can supply steam, the reduction of steam consumption will end, and an abnormal situation will occur in the steam use section due to the shortage of steam supply even before and after full blow. Can be prevented.

Flow diagram of a steam supply system implementing the present invention Explanatory diagram showing the relationship between the boiler operating state and the steam supply state

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a flow chart of a steam supply system embodying the present invention, and FIG. 2 is an explanatory diagram showing the relationship between the operating state of a boiler and the state of steam supply to a steam use section. In this embodiment, three boilers 1 are installed, and each boiler 1 is connected to the steam header 4 through a steam pipe 5. Steam generated in each boiler 1 gathers in the steam header 4 and supplies steam from the steam header 4 to a plurality of steam use units 2 provided. The steam header 4 is provided with a pressure detection device 6 for detecting the steam pressure, and information on the steam pressure value detected by the pressure detection device 6 is output to the number control device 3. Each boiler 1 is provided with an operation control device 7, and each operation control device 7 is connected to the number control device 3. The steam use part 2 has four locations of A, B, C, and D, and is connected to the steam header 4 by a steam pipe 5. Each steam pipe 5 connecting between the steam header 4 and each steam use section 2 is provided with a steam supply control valve 8, and steam supplied to each steam use section 2 is supplied to the steam pipe 5. The supply control valve 8 can be controlled.

  The operation control of the boiler is normally performed by the number control device 3 and the operation control device 7 provided in each boiler. The number control device 3 is set with a combustion pattern that determines the number of boilers to be burned according to the steam pressure value, and the operation priority of each boiler. The number control device 3 calculates the required number of combustion based on the steam pressure value detected by the pressure detection device 6, and outputs a combustion request signal to the boilers for the number of combustions calculated from the boilers with higher operation priority. The number control device 3 reduces the number of boilers that output a combustion request signal when the steam pressure value detected by the pressure detection device 6 increases, and outputs the combustion request signal when the steam pressure value decreases. Increase the number. Further, each boiler 1 is provided with a boiler pressure detector 9 for calculating a steam pressure value in each boiler 1, and the steam pressure value detected by the boiler pressure detector 9 is sent to the operation controller 7. ing. In each boiler 1, it is also possible to perform operation control independently based on the steam pressure value detected by the boiler section pressure detection device 9 without using the number control device 3.

  The boiler 1 burns to heat the can water in the boiler to generate steam, and the generated steam is taken out to the steam header 4 through the steam pipe 5. In the boiler, when the can water is reduced by evaporation, the water is replenished, and the impurities contained in the can water in the boiler are gradually concentrated by repeating the water supply and evaporation. For this reason, it is necessary to periodically carry out all blows for discharging sludge accumulated in the can, and during the full blows, combustion is stopped and steam cannot be supplied.

  In FIG. 2, it is a thing at the time of starting full blow of boiler No. 3 can at the time c. The execution of all blows is determined for each boiler, and the combustion time performed after the previous full blow is measured, and when the combustion time reaches a predetermined time, the full blow execution time is reached. The boiler 1 outputs a signal (notification signal) for notifying the execution of all blows before carrying out all blows. The output of the notification signal starts at time a which is X minutes before time c at which all blows are actually started. The notification of all blows is performed by turning on the indicator lamp or by displaying characters on the display screen.

  If the steam generation capacity in the entire boiler is sufficiently larger than the steam consumption in the entire steam use section, the steam supply will not be insufficient even if one boiler stops combustion. Even if the boiler is stopped to carry out the blow, there is no influence on the steam use section 2. However, if the boiler starts full blow when there is not enough room for the steam supply amount, the steam supply amount may decrease and the steam supply may be insufficient. If the steam using unit 2 requires a predetermined steam pressure or steam flow rate, the steam using unit 2 may not be able to maintain the predetermined steam pressure or steam flow rate due to a decrease in the steam supply amount. There will be an effect that the quality of the product produced by the steam using part 2 is deteriorated due to stoppage or incomplete operation. In this case, an abnormality occurs in all of the steam use parts A, B, C, and D.

  In such a case, the amount of steam used in the steam using unit 2 is reduced prior to the start of all blows based on the output of all blow notification. In this embodiment, in response to the all blow execution notification signal, the operation of the steam use part D is stopped at time b, the steam supply control valve 8 that controls the steam supply is operated, and the steam use part D is controlled. Steam supply is stopped. By stopping the operation of the steam using part D, the required amount of steam in the entire steam using part 2 can be reduced.

  Thereafter, full blow of boiler No. 3 can is started at time c. Since the steam supply from the boiler No. 3 can not be performed while the boiler No. 3 can perform all blows, the steam supply amount in the entire boiler decreases. However, even if the steam supply amount decreases due to the combustion stop by all blows, the steam supply amount does not fall below the steam use amount by reducing the steam amount used in the steam using unit 2 in advance. It can be prevented that the pressure of the steam supplied from the steam header 4 to the steam using unit 2 is lowered. The steam generated in boiler No. 1 and No. 2 can be supplied only to the steam use part A, B, C, so that the required amount of steam can be supplied to the steam use part A, B, C. In the steam use parts A, B, and C, the operation can be continued normally.

  When all blows of the boiler No. 3 can be completed at time d, the boiler No. 3 can performs a combustion preparation process and starts combustion. Although all blows in the boiler No. 3 can be completed at time d, steam supply from the boiler No. 3 can not be performed at this time. Steam supply from No. 3 can boiler is not after supplying water to the boiler, burning in the boiler to heat the can water in the boiler, and after the steam pressure in the boiler rises to the pressure in the steam header, Since steam cannot be supplied to the steam header 4, the output of all blow notifications is still continued, and the operation of the steam using part D is stopped. The output of all blow notification starts combustion in the boiler No. 3 can and continues until time e when the internal pressure of the boiler No. 3 can reaches the set pressure X, and stops the output of all blow notification at time e. After that, the steam supply to the steam using part D is restarted, and the operation of the steam using part D is restarted.

  If the above control is performed, even if the steam supply volume decreases due to the implementation of full blow, the steam supply to all the steam use parts will not be insufficient, and the necessary steam pressure value and steam flow rate will be maintained. By not being able to do so, it is possible to prevent the worst situation that abnormality occurs in all the steam using parts.

  In this embodiment, the steam consumption is reduced by stopping the steam supply to a part of the plurality of steam use sections installed, but the steam consumption is reduced while the steam is being sent. May be. For example, in the steam use section, heating and heat insulation are performed with steam, and when the heating operation using a large amount of steam is performed intermittently, the heating operation is performed while the notification signal for all blows is output. It is possible to reduce the amount of steam used even if not performed.

DESCRIPTION OF SYMBOLS 1 Boiler 2 Steam use part 3 Number control device 4 Steam header 5 Steam piping 6 Pressure detection device 7 Operation control device 8 Steam supply control valve 9 Boiler part pressure detection device

Claims (2)

  In a steam supply system consisting of a boiler that generates steam by heating water and a steam using part that uses steam generated in the boiler, all blows to stop boiler combustion and discharge canned water in the boiler In the case of performing, the output of a notification signal for informing in advance that all the blows have been performed at a time before the start of all the blows is started, and the steam in the steam using section before performing all the blows is started based on the notification signals. A steam supply system characterized by reducing the amount used and then starting full blow.   The steam supply system according to claim 1, wherein the output of a notification signal for notifying execution of all blows is continued until a time later than the end of all blows, and the notification signal is maintained even after all blows are completed. It is to be noted that the steam usage reduction in the steam use section is continued while the steam is being output, and the steam use reduction in the steam use section is to be terminated after the signal for carrying out all the blows is over. A featured steam supply system.

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