JP4985964B2 - Number control device and multi-can installation system - Google Patents

Description

  The present invention relates to a multi-can installation system in which a plurality of boilers such as steam boilers and hot water boilers are installed, and a unit control device for controlling the number of boilers to be burned based on the priority set between the boilers, and the number control thereof The present invention relates to a multi-can installation system equipped with a device.

  There is a multi-can installation system in which the output of each boiler is efficiently gathered and supplied to the user by controlling the number of combustion of small boilers installed in a plurality. If it is a steam boiler, each boiler will be connected to a common steam header, the steam from each boiler will be collected in a steam header, and steam will be supplied to load from the steam header. The steam header is provided with a pressure detector to grasp the state of the load. In addition, an operation priority order is preset for each boiler. The unit control device that controls the number of combustion sets the required number of combustion based on the detection result of the pressure detector, burns in order from the boiler with the highest priority, secures the required number of combustion, and stops the remaining boilers (For example, refer to Patent Document 1).

In such a multi-can installation system, rotation for changing the operation priority is performed. This is because if the priority order is fixed, the operation time (burning time) of some boilers is significantly longer than other boilers, and the life of the entire system is shortened. For example, the operation time of each boiler can be averaged by accumulating the operation time of each boiler every day and increasing the priority in ascending order of the integrated value. In addition to rotation, the priority order may be changed for various purposes such as preferential combustion for the purpose of protecting the can body to increase the concentration in the can with respect to the boiler that has performed full blow.
JP-A-2-21102

  In the conventional number control device, the necessary number of combustion is determined as described above, and the number of combustion is ensured by burning sequentially from the boilers with the highest priority. As a result, the priority order set for each boiler always matches the actual combustion state of each boiler. The same control is performed when the priority order is changed due to rotation or full blow.

  However, not only when the required number of combustion units fluctuates but also when the priority is changed, there is a possibility that sufficient output cannot be temporarily secured by switching the combustion boiler. If the priority of the boiler that was burning before the change in priority is lowered due to the change, the stop instruction is given to the boiler, while the priority of the boiler that was waiting before the change in priority becomes higher, This is because a combustion instruction is given to the boiler. Even if a combustion instruction is given to a boiler that is in a standby state, it takes a certain amount of time for the boiler to be able to supply steam. Stops. Before the boiler can supply steam, the time required to start combustion, such as purge or ignition, or the time to heat the boiler to a state where steam can be supplied after starting combustion. is necessary.

  The present invention relates to a unit control device, a unit control program, and a multi-can installation system provided with the unit control device capable of stabilizing the output of the multi-can installation system even when the priority order among boilers is changed. It is an issue to provide.

  According to one aspect of the present invention, there is provided a number control device for a multi-can installation system in which a plurality of boilers having a plurality of combustion stages including standby are installed. This number control device compares priority between candidate boilers, priority changing means for changing priority among boilers, candidate boiler determining means for determining candidate boilers for changing the combustion stage in the boiler, and candidate boilers The target boiler selecting means for selecting the target boiler whose combustion stage is to be changed from the candidate boilers, and the combustion stage indicating means for instructing the change of the combustion stage for the target boiler. Is changed, the change of the combustion stage is required due to the fluctuation of the required load, and the change of the combustion stage is instructed for the target boiler.

  In this number control device, the target boiler is selected by comparing priorities among candidate boilers, instead of burning in order from the boilers with the highest priority, and the change of the combustion stage is instructed for the target boiler. The priority order of the boilers other than the candidate boilers is not referred to, and the combustion stage of the boilers other than the candidate boilers is not changed. For example, if the boiler in the combustion state is not used as a candidate boiler, it is possible to avoid stopping the boiler even if the priority order among the boilers is changed due to rotation or full blow. Further, if the combustion amount becomes excessive or insufficient and the combustion stage needs to be changed, an appropriate boiler may be selected as the target boiler. In addition, for the target boiler, after the priority order among the boilers is changed, the change of the combustion stage is instructed after the change of the required load causes the change of the combustion stage. Even if the priority order among the boilers is changed, the combustion stage of the boiler is maintained until the combustion stage needs to be changed due to fluctuations in the required load. Therefore, in this number control device, even if there is a change in the priority order, excess and deficiency in the amount of combustion hardly occurs, and the output of the multi-can installation system can be stabilized.

  Moreover, the target boiler is selected by comparing priorities among candidate boilers. For this reason, even if it is not necessary to immediately and simultaneously switch the combustion state of the boiler by changing the priority order, the priority order is changed by gradually changing when the combustion stage needs to be changed due to fluctuations in the required load. Will be reflected in the combustion stage of each boiler. Therefore, the original purpose of changing the priority order such as rotation is not impaired.

  When it becomes necessary to raise the combustion stage due to fluctuations in the required load, the candidate boiler determining means decides the boiler that can raise the combustion stage as the candidate boiler, and the target boiler selection means is the priority after the change in the candidate boiler It is possible to select a boiler to be lifted that raises the combustion stage from the ones with higher ranks.

  When it becomes necessary to lower the combustion stage due to fluctuations in the required load, the candidate boiler determining means determines the boiler that is in the combustion state as the lowering candidate boiler, and the target boiler selecting means determines the priority order after the change in the lowering candidate boiler. It is also possible to select a lowering target boiler that lowers the combustion stage from the lowest.

  The number control device may further include a control target boiler that is selected in descending order of priority among the boilers, and a spare can setting unit that sets a spare can boiler other than the control target boiler.

  Of the multiple boilers provided in the multi-can installation system, the spare boiler can be stopped or put on standby in principle. The load of the multi-can installation system decreases depending on the time of day, such as at night, and the output is more stabilized by controlling with a smaller number of units than the normal load, and the load varies depending on the season and time of day. This is to make it stop as much as possible to save energy and labor.

  A control object boiler and a backup can boiler can be determined by selecting the control object boiler for a predetermined number from a thing with high priority, for example. The spare can boiler will be selected from those with lower priority. For this reason, if the priority order is changed, the control target boiler and the spare can boiler are also changed. When the control target boiler is changed to a spare can boiler due to the change in the priority order, if the spare can boiler is immediately stopped, there is a possibility that the output of the multi-can installation system cannot be sufficiently secured for the required load.

  Therefore, when the candidate boiler determination means needs to lower the combustion stage due to fluctuations in the required load after the priority order between the boilers is changed, the candidate for lowering the combustion stage in the controlled boiler and the spare can boiler You may make it determine a boiler.

  In this case, even if there is a change in the priority order, it is necessary to lower the combustion stage due to fluctuations in the required load. If the spare can boiler does not become a candidate for reduction, the spare can boiler does not stand by. Even if the boiler to be controlled changes to a spare can boiler due to the change in priority, it will not stop immediately, but will be determined as a candidate for reduction from among the boilers including the spare can boiler, The combustion stage of the boiler is lowered.

  For this reason, even when some of the plurality of boilers are used as spare can boilers, it becomes difficult for the combustion amount to be insufficient due to the change in the priority order, and the output of the multi-can installation system can be further stabilized.

  Also, the candidate boiler determining means determines the candidate boiler for raising the combustion stage among the controlled boilers when it becomes necessary to raise the combustion stage due to fluctuations in the required load after the priority order among the boilers is changed. You can also. In other words, when selecting a boiler that raises the combustion stage, the spare can boiler is removed from the candidate boilers for raising.

  For this reason, when the controlled boiler is changed to the spare can boiler due to the change of the priority order, even if the spare can boiler does not stop immediately, the standby state is sequentially entered due to the fluctuation of the required load thereafter. That is, when it is necessary to raise the combustion stage, the state is maintained without raising the combustion stage of the preliminary can boiler, and when the combustion stage needs to be lowered, the combustion stage of the preliminary can boiler is preferentially lowered. The spare can boilers are sequentially put on standby. For this reason, it can prevent that a preliminary | backup can boiler continues combustion for a long term.

  In this way, while stabilizing the output of the multi-can installation system, it is possible to improve the controllability of the entire system by reducing the number of boilers to be controlled by setting up spare can boilers, and to save energy and labor It becomes possible.

  According to another aspect of the present invention, a number control program for causing a computer or an embedded device to function is provided as the above-described number control device.

  Moreover, according to the further another aspect of this invention, the multi-can installation system provided with the above-mentioned number control apparatus is provided. This multi-can installation system can perform stable output even when the priority order among boilers is changed.

  By adopting the above configuration, it is possible to stabilize the output of the multi-can installation system even when the priority order among the boilers is changed.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following embodiments, the present invention is realized as a number control device of a multi-can installation system in which a plurality of steam boilers having three combustion stages of low combustion, high combustion, and standby (stop) are installed.

  FIG. 1 is a diagram schematically showing the overall configuration of a multi-can installation system in the present embodiment. Here, the multi-can installation system includes five three-position steam boilers 101. The three-position boiler 101 burns in a low-burning or high-burning state due to the difference in supplied fuel. For example, when the combustion amount at high combustion in each boiler 101 is about twice that at low combustion, if the combustion amount at high combustion is counted as 1.0, the combustion amount of each boiler 101 is changed in 0.5 increments. Will be able to. Instead of the three-position boiler, an on / off boiler may be used, a low-burning / medium / high-burning four-position boiler, or other multi-position boilers may be used.

  All the boilers 101 are connected to the steam header 102 through the steam pipe 103. The steam from the boiler 101 collects in the steam header 102 through the steam pipe 103. The steam header 102 is connected to the user's equipment and supplies the collected steam to the equipment.

  A pressure detector 104 is disposed in the steam header 102. The pressure detector 104 detects the steam pressure inside the steam header 102. If the load increases due to an increase in demand for user equipment and the amount of supplied steam is insufficient, the steam pressure inside the steam header 102 decreases. On the other hand, if the load decreases due to a decrease in demand for user equipment and the amount of supplied steam becomes excessive, the steam pressure inside the steam header 102 increases. For this reason, the load fluctuation can be monitored by the pressure detection signal from the pressure detector 104.

  The pressure detector 104 is connected to the number control device 105 by a signal line 106. The number controller 105 receives a pressure detection signal from the pressure detector 104 via the signal line 106. The number control device 105 determines a necessary combustion amount corresponding to the required load based on the pressure detection signal from the pressure detector 104, and instructs each boiler 101 to change the combustion stage according to the required combustion amount. The combustion amount of the boiler 101 is controlled. As described above, assuming that the combustion amount at the time of high combustion in each boiler 101 is 1.0, the total combustion amount of the five boilers 101 can be changed from 0.0 to 5.0 in 0.5 increments. .

  The number control device 105 instructs the boiler 101 to raise the combustion stage from standby to low fuel or from low to high fuel when the combustion amount is insufficient due to fluctuations in the required load. If the combustion amount is excessive due to fluctuations in the required load, the boiler 101 is instructed to lower the combustion stage from high fuel to low fuel, from low fuel to standby, or from high fuel to standby.

  Here, the start / stop of the boiler 101 can be handled in units of virtual boilers. A virtual boiler is a boiler that treats the differences in the amount of combustion (low combustion, medium combustion, high combustion, etc.) of the boiler as described above as independent boilers. . For example, in the case of an on / off boiler, there is one virtual boiler, which matches the actual number of physical boilers. Further, even if the three-position boiler is physically one unit, it can be virtually counted as two units of a low combustion evaporation amount boiler and a (high combustion evaporation amount-low combustion evaporation amount) boiler. The four-position boiler can be virtually counted as three boilers: a low combustion evaporation amount boiler, a (medium combustion evaporation amount-low combustion evaporation amount) boiler, and a (high combustion evaporation amount-medium combustion evaporation amount) boiler. Therefore, if the three-position boiler is in a low combustion state, a combustion instruction is given to the low combustion evaporation boiler, and a stop instruction is given to the (high combustion evaporation-low combustion evaporation) boiler. It can be handled for control.

  The number control device 105 is connected to the control module of each boiler 101 via a signal line 107. The number control device 105 gives various instructions to the control module of each boiler 101 via the signal line 107 and receives various data from the control module to perform the above-described control on the five boilers 101. Do. When the control module of each boiler 101 receives a signal for changing the combustion stage from the number control device 105, it controls the boiler according to the instruction. Further, the actual combustion state of the boiler and other data are transmitted to the number control device 105. If the actual combustion amount is insufficient relative to the required combustion amount determined from the load amount of the multi-can installation system, the boiler is instructed to combust. If the actual combustion amount is excessive, the boiler is instructed to stop. Do.

  The number control device 105 can be used as an operation panel in a boiler room. For this reason, a liquid crystal display 108 with a touch panel is provided on the front side. The display 108 can be used to set parameters and control methods such as target values and control widths, and display the status and alarms at that time.

  FIG. 2 is a diagram illustrating an example of a hardware configuration used in the number control device according to the present embodiment. In addition to the general-purpose information processing circuit as in this example, a dedicated circuit specialized for the purpose can be used for the number control device 105. The number control device 105 includes an MPU 201 and a bus 202. The MPU 201 is connected to an I / O 203, a communication interface 204, a display interface 205, and a storage device 206 through a bus 202. The MPU 201 implements the function of the number control device 105 by performing input / output with these.

  The I / O 203 connects the pressure detector 104 to the number control device 105 via the signal line 106 and receives a pressure detection signal from the pressure detector 104. The communication interface 204 connects the boiler 101 to the number control device 105 via the signal line 107. The five boilers 101 may be connected to the communication interface 204 in cascade, or may be connected in other forms. Further, a repeater may be arranged on the signal line 107 as necessary. A display interface 205 connects the display 108 to the bus 202. The display interface 205 receives a command from the MPU 201, generates a display signal for the LCD 207, and outputs an input signal from the touch panel 208 to the MPU 201.

  As the storage device 206, a nonvolatile memory such as a flash memory, a volatile memory such as a RAM, or other storage can be used. This storage device 206 stores the code of the control program 209. The MPU 201 reads out the code of the control program 209 from the storage device 206 and inputs / outputs the device on the bus 202 in accordance with the command of the program 209.

  The storage device 206 further stores a boiler management table 210 and a priority order table 211. The boiler management table 210 stores an instruction given to each boiler 101 under the control of the MPU 201 and a state received from each boiler 101. The priority order table 211 stores the priority order setting among the boilers 101 for each boiler 101.

  The priority order is used to select a boiler that gives a combustion instruction or a stop instruction. The priority order can be set, for example, using an integer value so that the lower the numerical value, the higher the priority order. When the priority order of “1” to “5” is assigned to each of the first to fifth units of the boiler 101, the first unit has the highest priority and the fifth unit has the lowest priority.

  In addition to such priority order settings, the storage device 206 also stores control target values, parameters such as control widths, and operation setting data input from the touch panel display 108 or the like. This data also includes setting data regarding rotation for changing the priority order. The setting data includes data such as rotation intervals and execution times. Due to the rotation, for example, the priority order of No. 1 to No. 5 is changed in reverse order. In addition to such rotation, the priority order is changed when the priority order of the relevant boiler is increased by performing all blows, or when a boiler with a high priority order returns from a non-combustible state.

  FIG. 3 is a diagram for explaining an example of the priority order table. In this example, the priority table 211 has a record for each boiler. Each record includes data of items such as a boiler identifier, a priority, and a previous priority. The boiler identifier is a code used by the MPU 201 to identify the boiler. In this example, the number of each boiler is described as character data such as “No. 1” to “No. 5”. The priority order stores numerical data of the priority order assigned to each boiler such as “1” to “5”. In this example, “5” is assigned as priority to the No. 1 boiler, and “4” is assigned as priority to the No. 2 boiler. When a boiler is out of order, the record for the boiler can be temporarily deleted, numerical data can not be written to the priority value of the boiler, or a specific code can be written. When changing the priority order of each boiler, the MPU 201 rewrites data in the priority order table 211. The previous priority item stores numerical data of the priority prior to the change.

  In this number control device 105, the MPU 201 performs control so that the output of the multi-can installation system can be stabilized even if the priority order is changed due to rotation or the like. After the priority is changed, the boiler 101 is not instructed to change the combustion stage until the combustion quantity (or steam quantity) becomes insufficient or excessive due to fluctuations in the required load and the combustion stage needs to be changed. . For example, even if the priority of a boiler in a high combustion state is changed to the lowest priority, the boiler is not immediately stopped at the time of the change. If it is necessary to change the combustion stage due to a shortage of steam, select another boiler that can increase the combustion quantity based on the priority after the change, and then select the combustion stage for the selected boiler. Give instructions to raise. Such a control function is realized by the MPU 201 performing input / output to the boiler management table 210 and the combustion order table 211, calculation, and data processing in accordance with a command of the control program 209.

  FIG. 4 is a diagram for explaining a functional configuration of the number control device. The number control device 105 includes a detection signal reception unit 401, a combustion amount calculation unit 402, a state acquisition unit 403, a priority order change unit 404, a candidate boiler determination unit 405, a target boiler selection unit 406, and a combustion stage instruction unit 407.

  The detection signal receiving unit 401 receives a pressure detection signal representing the load of the multi-can installation system from the pressure detector 104. Based on the pressure detection signal from the pressure detector 104, the combustion amount calculation unit 402 calculates a necessary combustion amount corresponding to the steam pressure. The state acquisition unit 403 acquires the operation state data of the boiler 101 from the control module of each boiler 101 and writes the actual combustion stage of the boiler 101 in the boiler management table 210. The priority order changing unit 404 rewrites data in the priority order table 211 according to settings relating to rotation and the like, and changes the priority order setting.

  Candidate boiler determination unit 405 determines a candidate boiler that changes the combustion stage in boiler 101 in accordance with the combustion stage of boiler 101. Candidate boiler determination unit 405 reads the combustion stage of each boiler 101 from boiler management table 210. In this embodiment, the candidate boiler determination unit 405 determines a candidate boiler when it is necessary to change the combustion stage due to fluctuations in the required load. For example, by comparing the combustion amount of the entire system obtained from the combustion stage of each boiler 101 with the combustion amount from the combustion amount calculation unit 402 for each unit time, it is determined whether or not the combustion stage needs to be changed. be able to. When a shortage of combustion occurs due to fluctuations in the required load and it is necessary to raise the combustion stage, the boiler 101 whose combustion stage is other than the high combustion is determined as a candidate boiler for raising. Here, the boiler 101 whose combustion stage is standby or low in combustion is determined as the pulling candidate boiler. Boilers whose combustion stage is in standby or low combustion are boilers that can give a combustion instruction in units of virtual boilers. On the other hand, when the amount of combustion becomes excessive due to fluctuations in the required load, and it becomes necessary to lower the combustion stage, the boiler 101 whose combustion stage is other than standby is determined as a candidate boiler for lowering. That is, the boiler 101 whose combustion stage is low combustion or high combustion is determined as the reduction candidate boiler. Boilers whose combustion stage is at low combustion or high combustion are boilers that can be instructed to stop in units of virtual boilers. Even if the priority order among the boilers 101 is changed, the candidate boiler is not determined unless the combustion stage needs to be changed due to fluctuations in the required load. When the candidate boiler determination unit 405 determines a candidate boiler, the candidate boiler determination unit 405 supplies data for specifying the candidate boiler like the boiler identifier to the target boiler selection unit 406.

  The target boiler selection unit 406 selects a target boiler whose combustion stage is to be changed from the candidate boilers by comparing priorities among the candidate boilers. The target boiler selection unit 406 reads the priority order of candidate boilers from the priority order table 211. In the example of FIG. 3, when “No. 3”, “No. 4”, and “No. 5” are obtained from the candidate boiler determination unit 405 as the boiler identifiers, the target boiler selection unit 406 selects the boiler identifiers. The corresponding priority values “2”, “1”, and “3” are read from the priority table 211. When the priority order values are read, the target boiler selection unit 406 compares these values. When it becomes necessary to raise the combustion stage due to fluctuations in the required load, the boilers to be raised are selected in ascending order of the read values.

  For example, when it becomes necessary to raise the combustion stage due to fluctuations in the required load, the boilers to be raised are selected in ascending order of the read values. When “1” to “3” are read as the priority values, the value “1” is the smallest, so the target boiler selection unit 406 selects the No. 4 boiler corresponding to the value as the target boiler to be raised.

  When it is necessary to lower the combustion stage due to fluctuations in the required load, the reduction target boilers are selected in descending order of the read values. For example, when “4” and “5” are read as priority values, the value “5” is larger, so the target boiler selection unit 406 selects the No. 1 boiler corresponding to the value as the target boiler to be lowered. To do.

  When the target boiler is selected after the priority order is changed, the changed priority order is used for the selection. When the target boiler is selected, the target boiler selection unit 406 supplies data for specifying the target boiler to the combustion stage instruction unit 407.

  The combustion stage instruction | indication part 407 performs the instruction | indication which changes a combustion stage about an object boiler, and raises or lowers the combustion stage of the said object boiler. For boilers other than the target boiler, the combustion stage is maintained. In the virtual boiler unit, a combustion instruction or a stop instruction is transmitted. In this embodiment, the determination of the candidate boiler and the selection of the target boiler are performed after the combustion stage needs to be changed due to fluctuations in the required load even if the priority order among the boilers is changed. The combustion stage instructing unit 407 instructs the target boiler to change the combustion stage in accordance with the determination or selection timing.

  The combustion stage instruction unit 407 transmits an instruction to each boiler 101 and writes the instruction in the boiler management table 210. The control module of the boiler 101 controls the combustion stage of the boiler 101 according to the instruction, thereby adjusting the amount of steam according to the load of the multi-can installation system.

  FIG. 5 is a diagram for explaining an example of control by the number control device in the present embodiment. In this example, at time t1, the priorities from No. 1 boiler to No. 5 boiler are “5”, “4”, “2”, “1”, “3” to “1”, “2”, “4”. ”,“ 5 ”, and“ 3 ”. The upper part of FIG. 5 shows the steam header steam pressure and the required combustion amount obtained from the pressure in time series. The lower part of FIG. 5 shows the combustion stage of each boiler from No. 1 boiler to No. 5 boiler in time series.

  At the initial time t0 in this example, the required combustion amount is 2.5, and the combustion amount of the boiler capable of supplying steam (steaming boiler) is also 2.5. At the time t0, the combustion stage of the No. 4 boiler and the No. 3 boiler with high priority has high combustion, and the combustion stage of the No. 5 boiler with the next highest priority has low combustion. The combustion stage of No. 2 boiler and No. 1 boiler with low priority is standby.

  Assume that the priority is changed by rotation at time t1. At that time t1, if the boilers for instructing the combustion stage change are selected in the order of higher priority after the change, the No. 1 and No. 2 boilers are instructed to sequentially raise the combustion stage, and the No. 3 boiler. And the stop instruction | indication which makes them wait is performed with respect to No. 4 boiler. However, even if the instruction to raise the No. 1 boiler is given, it takes time until the steam can be supplied. For this reason, if the combustion stage of the boiler is raised or lowered by changing the priority order, the output of the multi-can installation system may become unstable.

  The number control device in this embodiment does not change the combustion stage of each boiler if there is no change in the required load even if the priority order is changed as described above. Whether there is a change in the required load is determined, for example, every 0.5 seconds. In this example, the required combustion amount does not change after time t1 when the priority is changed and before time t2. Therefore, the combustion stage change instruction is not performed, and the combustion stage of each boiler is maintained.

  At time t2, the steam pressure in the steam header has decreased, so the required amount of combustion increases from 2.5 to 3.0. If it is determined that the required amount of combustion has increased and the combustion stage needs to be raised, the number control device determines that the No. 1 boiler, No. 2 boiler, No. 5 boiler, or No. 5 boiler whose combustion stage is standby or low in combustion is selected as a candidate boiler. When the raising candidate boiler is determined, the raising target, which is an instruction target for raising the combustion stage, is selected by comparing the priorities after the change among the raising candidate boilers. The shortage of combustion amount is 0.5, and the priorities after the change for the three boilers are “1”, “2”, and “3” in order, so the No. 1 boiler is selected as the boiler to be lifted. Depending on the shortage of fuel, two or more boilers may be selected as the target boiler. Moreover, the combustion stage of No. 2 boilers to No. 5 boilers other than the boiler to be lifted is maintained. At this time, the five boilers 101 are not burned in order of priority after the change, and the combustion amount of the steamable boiler becomes 2.5.

  At time t3, the steam pressure in the steam header increases, so the required amount of combustion decreases from 3.0 to 2.5. When it is determined that the required combustion amount has decreased and the combustion stage needs to be lowered, the number control device determines that the combustion stage is the low boiler or the high combustion No. 1 boiler and the No. 3 boiler as the candidate boiler. . In this case, the number control device selects a lowering target boiler which is an instruction target for lowering the combustion stage by comparing priorities after the change from the No. 1 boiler and the No. 3 boiler to the No. 5 boiler. The shortage of combustion amount is 0.5, and the boiler with the lowest priority among the reduction candidate boilers is the No. 4 boiler, so the No. 4 boiler is selected as the reduction target boiler, and its combustion stage is from high to low Pulled down. When this time t3 has elapsed, the No. 1 boiler is in a steamable state, so the combustion amount of the steamable boiler is 2.5.

  At time t4, the steam pressure in the steam header further increases, so the required combustion amount decreases from 2.5 to 2.0. Similarly, the number control device selects the No. 4 boiler as the lowering target boiler, and the combustion stage of the No. 4 boiler is lowered from low combustion to standby. Thereby, the combustion amount of the steamable boiler becomes 2.0.

  Thus, even if the No. 4 boiler is not stopped at the time t1 when the priority order is changed, the No. 4 boiler is preferentially stopped when the required combustion amount is reduced, and the changed priority order and each boiler are changed. The combustion phase of the will be consistent. Compared with the interval for changing the priority order such as rotation, the time required for matching is extremely short, so that the combustion stage of each boiler is controlled substantially based on the priority order. Therefore, the effect of changing the priority order such as combustion control or rotation by priority order is not impaired.

  Further, when time elapses and time t5 is reached, the steam pressure in the steam header decreases, so that the required combustion amount increases from 2.0 to 2.5, and the combustion amount is insufficient by 0.5. When the number control device determines that the necessary combustion amount has increased and the combustion stage needs to be raised, the No. 1 boiler, the No. 2 boiler, the No. 4 boiler, the No. 4 boiler, and the No. 5 boiler that are in the low combustion stage or the standby stage are raised. Determine as. Among the candidate boilers for raising, the first boiler with the highest priority at that time is selected as the boiler to be raised. The combustion stage of the No. 1 boiler is raised from low combustion to high combustion, and the combustion amount of the steamable boiler increases to 2.5.

  At time t6, the steam pressure in the steam header further decreases, so that the required combustion amount increases from 2.5 to 3.0, and the combustion amount becomes insufficient by 0.5. The number control device determines the No. 2 boiler, the No. 4 boiler, and the No. 5 boiler whose combustion stage is low in combustion or standby as a candidate boiler. Among the candidate boilers for raising, the No. 2 boiler having the highest priority at that time is selected as the target boiler to be raised. The combustion amount of the steamable boiler remains 2.5.

  At time t7, the steam pressure in the steam header increases again, so the required amount of combustion decreases from 3.0 to 2.5 and the amount of combustion becomes excessive by 0.5. The number control device then determines four boilers whose combustion stage is high or low as pulling down candidate boilers. From among the reduction candidate boilers, the No. 3 boiler having the lowest priority at that time is selected as the reduction target boiler. While the combustion stage of the No. 3 boiler is lowered from high combustion to low combustion, since the No. 2 boiler can be steamed when the time t7 has elapsed, the combustion amount of the steamable boiler becomes 2.5. ing.

  At time t8, the steam pressure in the steam header further increases, so the required amount of combustion decreases from 2.5 to 2.0, and the amount of combustion becomes excessive by 0.5. The number control device then determines four boilers whose combustion stage is high or low in combustion as candidate boilers to be lowered. Similarly, the No. 3 boiler is selected as the reduction target boiler from the reduction candidate boilers. The combustion stage of the No. 3 boiler is lowered from low combustion to standby, and the combustion amount of the steamable boiler is reduced to 2.0. Thereby, the No. 3 boiler and the No. 4 boiler are in a standby state according to the priority after the change.

  At time t9, the steam pressure in the steam header decreases, so the required amount of combustion increases from 2.0 to 2.5. At this time, the number control device raises the No. 5 boiler from the No. 2 boiler whose combustion stage is low combustion or standby, and determines it as a candidate boiler. Among the candidate boilers for raising, No. 2 boiler with the highest priority is selected as the target boiler for raising. The combustion stage of No. 2 boiler is raised from low combustion to high combustion, and the combustion amount of steamable boiler increases to 2.5. This ensures that the combustion stage of each boiler is in priority order.

  As described above, the number control device according to the present embodiment, even if the priority setting is changed, when the combustion stage needs to be changed due to fluctuations in the required load, the candidate boilers are changed according to the combustion stage at that time. Select. By removing the combustion boiler from the candidate boiler, the combustion stage of the combustion boiler is not lowered. The combustion stage is changed only for the target boiler, and the combustion stages of the other boilers are maintained. Even if there is a change in priority, the combustion boilers are not replaced immediately and all at once, but the steam pressure is stabilized by gradually replacing the combustion stage when it is necessary to change the combustion stage due to fluctuations in the required load. It is possible to change the priority in the state of being made.

  In the above example, the number control device controls all the boilers provided in the multi-can installation system. However, depending on the time zone such as night, the load of the multi-can installation system may steadily decrease, or an unnecessary boiler may be generated because the load amount varies depending on the season or time zone. For this reason, for the purpose of energy saving / labor saving and improvement in controllability, a part of the installed boilers may be controlled boilers and the remaining boilers may be spare cans. Unnecessary boilers, etc. are kept in standby as a spare can in principle.

  As shown in FIG. 4, the number control device 105 may further include a spare can setting unit 408 in order to set such a control target boiler and a spare can boiler. The spare can setting unit 408 selects the control target boilers corresponding to the preset maximum number of combustion units in descending order of priority, so that the boilers other than the control target boiler and the control target boiler are selected from the boilers 101. To decide. For example, if the maximum number of combustion units is set to three, among the five boilers 101, three boilers with higher priority are set as control target boilers, and two boilers with lower priority are spare boilers. Set as

  When there is a priority change notification from the priority changing unit 404, the spare can setting unit 408 refers to the priority order table 211, sets the controlled boiler and the spare can boiler, and writes the settings to the boiler management table 210. . For example, in the boiler management table 210, a flag indicating whether the boiler is a controlled boiler or a spare can boiler is prepared for each boiler, and the spare can setting unit 408 determines the flag according to the determination result of the controlled boiler and the spare can boiler. It is sufficient to write the value of.

  In this case, when it becomes necessary to lower the combustion stage due to fluctuations in the required load, the candidate boiler determination unit 405 determines a lowering candidate boiler that lowers the combustion stage from among the control target boiler and the spare can boiler. This determination can be made according to the combustion stage of the controlled boiler and the spare can boiler. The target boiler selection unit 406 selects a lowering target boiler that lowers the combustion stage from the lower priority among the lowering candidate boilers. As in the above example, even if the priority order is changed, if it is necessary to lower the combustion stage due to fluctuations in the required load and the reduction candidate boiler is not determined, the reduction target boiler is not selected and the reduction target boiler is selected. The combustion stage of the other boilers is maintained including the combustion stage of the spare can boiler. That is, even if the control target boiler is changed to the spare can boiler due to the change of the priority order, it does not stop immediately. When it is necessary to lower the combustion stage due to fluctuations in the required load, a boiler that lowers the combustion stage is selected from the boilers including the spare can boiler based on the changed priority.

  For this reason, even when a part of the boiler 101 is a spare can boiler, a shortage of the combustion amount is less likely to occur due to the change in the priority order, and the output of the multi-can installation system can be further stabilized.

  Further, when it becomes necessary to raise the combustion stage due to fluctuations in the required load, the candidate boiler determining unit 405 determines a candidate boiler to be raised from among the boilers to be controlled, and the target boiler selecting unit 406 prioritizes these candidate boilers for raising. By comparing the ranks, it is possible to select the target boiler for the increase.

  When selecting the boiler to be lifted, the spare can boiler is not included in the candidate boilers for lifting. When the boiler to be controlled is changed to a spare can boiler due to the change in priority, even if the spare can boiler does not immediately go to standby, the spare can boiler can only be instructed to pull down, so the spare can boiler is put into a standby state sequentially. Become. Therefore, it is possible to prevent the preliminary can boiler from continuing to burn for a long time.

  FIG. 6 is a diagram for explaining another example of the control by the number control device in the present embodiment. Also in this example, at time t1, the priorities from the No. 1 boiler to the No. 5 boiler are “5”, “4”, “2”, “1”, “3” to “1”, “2”, “4”. ”,“ 5 ”, and“ 3 ”. However, since the maximum number of combustion is set to three instead of five, two of the five boilers are spare can boilers.

  At the initial time t0 in this example, the required combustion amount is 2.0, and the combustion amount of the steamable boiler is also 2.0. At the time t0, the combustion stage of the No. 4 boiler and the No. 3 boiler with high priority is high combustion, and the combustion stage of the No. 5 boiler with the next highest priority is standby. These three are controlled boilers, and the remaining No. 2 and No. 1 boilers are spare boilers.

  From this time t0 to time t1, the priority is changed as described above. At the time t1, if the No. 4 boiler and the No. 3 boiler are set as spare can boilers in the order of lower priority after the change, and if they are put on standby immediately, the combustion amount of the steaming boiler becomes 0.0. As a result, the required amount of combustion is greatly insufficient.

  In this example, even if the control target boiler and the spare can boiler change due to the change in the priority order, if it is not necessary to change the combustion stage due to fluctuations in the required load, the combustion stage of the spare can boiler before the change is put on standby. Do not instruct changes. At time t1, no lowering instruction is issued to the No. 4 and No. 3 boilers, and the combustion stage of both boilers is maintained. As a result, the combustion amount of the steamable boiler can be maintained at 2.0 even at the time t1 when the priority is changed.

  At time t2, the steam pressure in the steam header decreases, so the required combustion amount increases from 2.0 to 2.5. When the number control device determines that it is necessary to raise the combustion stage due to fluctuations in the required load, the No. 1 boiler, the No. 2 boiler, and the No. 5 boiler that can raise the combustion stage are determined as candidate boilers to be raised. Then, a boiler to be raised is selected from the boiler candidate boilers to be raised based on the priority order of the boilers. The shortage of combustion amount is 0.5, and the priority order after the change for the three candidate boilers to be raised is “1”, “2”, “3” in order, so the No. 1 boiler is selected as the boiler to be raised. The Although this raises the combustion stage of the No. 1 boiler from standby to low combustion, it takes time for the No. 1 boiler to become steamable. However, the combustion stages of the boilers other than the No. 1 boiler are maintained including the combustion stages of the No. 3 boiler and the No. 4 boiler which are spare can boilers. For this reason, even if there is a change in priority, the combustion amount does not decrease, and the combustion amount of the steamable boiler at this time is 2.0.

  At time t3, the steam pressure in the steam header increases, so the required amount of combustion decreases from 2.5 to 2.0 and the amount of combustion becomes excessive by 0.5. When determining that it is necessary to lower the combustion stage due to fluctuations in the required load, the unit control device determines the boiler to be controlled and the spare can boiler in the combustion state as reduction candidate boilers, and based on the priority order of these reduction candidate boilers Select the target boiler. Of these reduction candidate boilers, the boiler with the lowest priority is the No. 4 boiler that has become a spare can boiler due to the change in the priority, and therefore the combustion stage of the No. 4 boiler is reduced from high to low. When this time t3 has elapsed, the No. 1 boiler is in a steamable state, so the combustion amount of the steamable boiler is 2.0.

  At time t4, the steam pressure in the steam header decreases again, so that the required combustion amount increases from 2.0 to 2.5, and the combustion amount becomes insufficient by 0.5. The number control device determines the No. 1 boiler, No. 2, No. 2 boiler and No. 5 boiler, which are the controlled boilers at that time, which can raise the combustion stage, as the candidate boilers, and raises the No. 1 boiler with the highest priority. Select as. As a result, the combustion stage of the No. 1 boiler is raised from low combustion to high combustion, and the amount of combustion of the steamable boiler becomes 2.5.

  At time t5, the steam pressure in the steam header increases, so the required amount of combustion decreases from 2.5 to 2.0 and the amount of combustion becomes excessive by 0.5. The number control device determines the No. 1 boiler, No. 3 boiler, and No. 4 boiler in the combustion state from among the boilers to be controlled and the spare can boiler as reduction candidate boilers, and lowers the No. 4 boiler with the lowest priority at that time. Select as target boiler. As a result, the combustion stage of the No. 4 boiler is lowered from low combustion to standby, and the combustion amount of the steamable boiler becomes 2.0.

  At time t6, the steam pressure in the steam header decreases, so the required combustion amount increases from 2.0 to 2.5, and the combustion amount becomes insufficient by 0.5. When determining that it is necessary to raise the combustion stage due to fluctuations in the required load, the unit control device determines the No. 2 and No. 5 boilers that are to be controlled and can raise the combustion stage as raising candidate boilers, and raises them. From the candidate boilers, the No. 2 boiler with the highest priority is selected as the target boiler. Thus, although an instruction to raise the combustion stage of the No. 2 boiler from standby to low combustion is given, since it is not in a steamable state, the amount of combustion in the steamable boiler is 2.0.

  In the control at the time t5 described above, when the controlled boiler and the spare can boiler change due to the change in the priority order, even if the No. 4 boiler that has become the spare can boiler is not stopped, The No. 4 boiler is preferentially stopped when it is necessary to lower the combustion stage. Further, in the control at the time t6, the No. 4 boiler, which is a spare can boiler, is excluded from the candidate boilers for lifting, and therefore the standby state of the No. 4 boiler continues. Even if the standby boiler is not put on standby immediately when the priority order is changed, the setting and actual setting of the spare can boiler can be performed by instructing the spare can boiler to be lowered without instructing to raise it. It will be consistent. Compared with the interval for changing the priority order such as rotation, the time required for matching is extremely short, so that the preliminary boiler can be substantially removed from the controlled object and continue to cool. Therefore, the effects of energy saving and labor saving by the spare can boiler are not impaired.

  When time elapses and time t7 is reached, the steam pressure in the steam header increases, so that the required combustion amount decreases from 2.5 to 2.0, and the combustion amount becomes excessive by 0.5. If it is determined that the combustion stage needs to be lowered due to fluctuations in the required load, the unit control device lowers the No. 1 to No. 3 boilers whose combustion stage is high or low among the control target boiler and the spare can boiler. The No. 3 boiler with the lowest priority is selected as the target boiler for reduction from among the reduction candidate boilers. As a result, the combustion stage of the No. 3 boiler is lowered from high combustion to low combustion. At this time, the No. 2 boiler is in a steamable state, and the combustion amount of the steamable boiler is 2.0.

  At time t8, the steam pressure in the steam header decreases, so the required amount of combustion increases from 2.0 to 2.5, and the amount of combustion is insufficient by 0.5. When determining that it is necessary to raise the combustion stage due to fluctuations in the required load, the number control device determines the No. 2 and No. 5 boilers whose combustion stage is low combustion or standby among the boilers to be controlled as the candidate boilers for raising, From among the candidate boilers for raising, the No. 2 boiler with the highest priority at that time is selected as the boiler to be raised. Thereby, the combustion stage of No. 2 boiler is pulled up from low combustion to high combustion, and the combustion amount of the steamable boiler becomes 2.5.

  At time t9, the steam pressure in the steam header increases, so that the required amount of combustion decreases from 2.5 to 2.0 and the amount of combustion becomes excessive by 0.5. When the number control device determines that the combustion stage needs to be lowered due to fluctuations in the required load, the first boiler with the combustion stage having high or low combustion among the control target boiler and the spare can boiler as at time t7. No. 3 boiler is determined as a reduction candidate boiler, and No. 3 boiler with the lowest priority is selected as the reduction target boiler from among the reduction candidate boilers. As a result, the combustion stage of the No. 3 boiler is lowered from low combustion to standby, and the combustion amount of the steamable boiler becomes 2.0. At this time, both the No. 3 boiler and No. 4 boiler, which are spare can boilers, are in a standby state, and are set according to the settings after the change of the spare can boiler.

  As described above, the number control device in the present embodiment updates the controlled boiler and the spare can boiler in accordance with the change in the priority order among the boilers while stabilizing the steam pressure output from the multi-can installation system. Can do. Further, when the controlled boiler is changed to the spare can boiler due to the change in the priority order, even if the spare can boiler is not immediately put on standby, the state is not continued, and the spare can boiler is sequentially put on standby. It is possible to prevent the spare can boiler from continuing to burn for a long time, and the effects of setting the spare can boiler such as energy saving, labor saving, and improvement in controllability are not impaired.

  The control program used in the above-described embodiment can be stored in a computer-readable medium. The computer readable medium includes a computer readable recording medium and a transmission medium. For example, a program code is expressed by an electric signal, an optical signal, a magnetic signal, etc., and the signal is placed on a carrier wave and transmitted, so that the program is provided on a transmission medium such as a coaxial cable, copper wire, or optical fiber. Can do. As a computer-readable recording medium, optical media such as CD-ROM and DVD-ROM, magnetic media such as a flexible disk, and semiconductor memory such as flash memory and RAM can be used.

  The above-described embodiment does not limit the technical scope of the present invention, and various modifications and applications can be made within the scope other than those already described. For example, when changing the priority setting as in the above-described embodiment, when the combustion-scheduled boiler has no pressure, the change is delayed until the pressure is increased, or the pressure is increased prior to the change. You may do it.

  Further, in the above-described embodiment, the setting of the control target boiler and the spare can boiler is updated when the priority change notification is sent from the priority change unit to the spare can setting unit, but the priority change and the update are performed. It is not necessary to synchronize.

  In the above-described embodiment, the candidate boiler is determined when the combustion stage becomes necessary due to fluctuations in the required load. However, the present invention is not limited to this. Instead of this, or together with this, a candidate boiler may be determined every predetermined period, and the combustion stage may be changed.

  Further, in the above-described embodiment, the candidate boiler is determined according to the actual combustion stage of the boiler. However, the candidate boiler may be determined by an instruction from the number control device to the boiler. This instruction may be an instruction to be given to the boiler from now on or may be an instruction content given to the boiler.

  Furthermore, in the above-described embodiment, the present invention is applied to a multi-can installation system provided with five three-position steam boilers. However, the present invention is not limited to this, and other types of boilers such as a hot water boiler are provided. It is also possible to apply to multi-can installation systems.

It is a figure which shows simply the whole structure of the multiple can installation system in this Embodiment. It is a figure which shows an example of the hardware constitutions used for the number control apparatus in this Embodiment. It is a figure for demonstrating an example of a priority table. It is a figure for demonstrating the functional structure of a number control apparatus. It is a figure for demonstrating the example of control by the number control apparatus in this Embodiment. It is a figure for demonstrating the other example of control by the number control apparatus in this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Boiler 102 Steam header 104 Pressure detector 105 Number control apparatus 209 Control program 210 Boiler management table 211 Priority order table 212 Conversion data 213 Pattern data 401 Detection signal receiving part 402 Number calculation part 403 Status acquisition part 404 Priority order change part 405 Candidate Boiler determination unit 406 Target boiler selection unit 407 Combustion stage instruction unit 408 Preliminary can setting unit

Claims (8)

A multi-can installation system unit control device in which a plurality of boilers having a plurality of combustion stages including standby are installed,
Priority changing means for changing the priority between the boilers;
Candidate boiler determining means for determining a candidate boiler for changing the combustion stage in the boiler;
A target boiler selecting means for selecting a target boiler for changing a combustion stage from the candidate boilers by comparing priorities among the candidate boilers;
Combustion stage instruction means for instructing the change of the combustion stage for the target boiler,
The number control device for instructing the change of the combustion stage for the target boiler after the combustion stage instructing means needs to be changed due to a change in required load after the priority order among the boilers is changed.   The number control device according to claim 1, wherein the combustion stage instruction means maintains a combustion stage of a boiler other than the target boiler. The candidate boiler determining means determines a boiler capable of raising the combustion stage as a candidate boiler when it is necessary to raise the combustion stage due to fluctuations in the required load,
3. The number control device according to claim 1, wherein the target boiler selecting unit selects a target boiler that raises a combustion stage from the candidate boilers having higher priority after the change. The candidate boiler determining means determines a boiler in a combustion state as a candidate boiler when it is necessary to lower the combustion stage due to fluctuations in required load,
The number control device according to any one of claims 1 to 3, wherein the target boiler selecting means selects a target boiler that lowers the combustion stage from the candidate boilers having a low priority after the change. Further comprising a control target boiler selected in descending order of priority between the boilers, and a preliminary can setting means for setting a preliminary can boiler other than the control target boiler;
The candidate boiler determining means lowers the combustion stage in the controlled boiler and the spare boiler when the combustion stage needs to be lowered due to a change in required load after the priority order between the boilers is changed. The number control device according to claim 1 or 2, wherein a candidate boiler is determined.   The candidate boiler determining means determines a candidate boiler for raising the combustion stage among the boilers to be controlled when it becomes necessary to raise the combustion stage due to a change in required load after the priority order among the boilers is changed. The number control device according to claim 5.   A number control program for causing a computer to function as the number control device according to any one of claims 1 to 6.   A multi-can installation system comprising a plurality of boilers and the number control device according to any one of claims 1 to 6.

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