JP2002073105A - Method and system for controlling number of installed devices - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform combustion control over a boiler by PID control and to calculate an optimum manipulated variable while taking the state of pressure fluctuation into consideration. SOLUTION: Steam pressure SP required for the steam pressure PV of a steam collection part 12 detected by a pressure sensor 13 is supplied and on the basis of their comparison, a device number controller 14 performs PID operation; and the continuous value of a manipulated variable as the operation result is converted into the output level of boiler number control and according to the output level, an operation control part 15 controls the combustion state of a combustion part 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the control of the number of installed equipment, and more particularly, to the automatic control of a plurality of installed boilers by burning a required number of boilers with the steam pressure of a common steam collecting section. The present invention relates to a method and system for controlling the number of installed devices to be controlled.

[0002]

2. Related Art Conventionally, this kind of number control system is used in a boiler. In the above system, the output level of the entire system of the system is mapped in advance in a table corresponding to the range of the steam pressure, the steam pressure in the steam collecting section is detected by the pressure sensor, and the detected steam pressure is corresponded to the detected steam pressure. The number of boilers in a combustion state is controlled by referring to the output level to be mapped from this mapped table.

[0003] Further, a method is also used in which a rate of change in steam pressure is detected, and the mapping is finely adjusted in accordance with the rate of change.

[0004]

However, in such a table reference type system, a technician performs mapping setting based on experience and intuition according to an installation environment and conditions.
Settings that do not match the actual situation may be made.For example, the dead time characteristic of pre-purge required when shifting from the stopped state to the low combustion state, the time delay characteristic from combustion to steam generation, the time delay characteristic of the pressure sensor, etc. The dynamic characteristics of the steam pressure are not compensated, so that the delicate control corresponding to the sudden fluctuation or the slow fluctuation of the steam pressure cannot be realized, and the unnecessary vertical movement of the steam pressure and the overshoot at the start of the system are likely to occur. There was a problem of becoming.

Furthermore, the above system cannot deal with the failure of one of the units, and the mapping becomes complicated as the number of boilers increases, and the burden of setting work for starting and stopping the boiler on site increases. There was a problem.
SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and the number of installed devices capable of calculating an optimal operation amount while controlling the operation of the installed devices by proportional-integral-derivative (PID) control and taking into account the situation of a control amount change. It is intended to provide a control system.

[0006]

In order to achieve the above object, according to the present invention, the operation control of a plurality of installed devices is performed, and the operation control of the installed devices for operating the required number of the installed devices is performed. A control amount common to the installed devices detected by the detection unit and a desired control amount given in advance are compared by a PID calculation unit, and an operation amount for operation control of the installed devices is obtained by a proportional integral derivative calculation, A method and system for controlling the number of installed devices, wherein the continuous value of the obtained manipulated variable is converted into an output level for controlling the number of installed devices by an output level converter.

That is, for example, in the control of the number of boilers,
A steam pressure, which is a desired control amount, is given to the detected steam pressure, which is a control amount, a PID calculation is performed based on the comparison, and a continuous value of the operation amount, which is the calculation result, is output to the output level of the number of boilers. The conversion alleviates the unnecessary vertical movement of the steam pressure and the occurrence of overshoot during system startup.

Further, according to the present invention, by changing the parameters of the PID calculation unit, it is possible to make fine adjustment corresponding to slightly different characteristics for each system, and to realize delicate control according to the situation. And

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a number control system using a method of controlling the number of installed devices according to the present invention will be described with reference to FIGS. FIG. 1 is a first embodiment showing a case where the system for controlling the number of installed devices according to the present invention is used for controlling the number of boilers. In the figure, in the present embodiment, a plurality of boilers (three as an example in the figure) 1
0 are installed in parallel, and steam generated from each boiler is collected in a steam collecting part 12 through each steam pipe 11. The steam collecting unit 12 is provided with a pressure sensor 13 constituting a detection unit of the present invention. The pressure sensor 13 detects a steam pressure PV which is a control amount of the present invention, and
Output to

The number control device 14 includes a PV input unit 14a for receiving a steam pressure PV, an SP input unit 14b for receiving a required steam pressure SP as a predetermined desired control amount, and a PID calculation for performing a PID calculation. Part 14c and P
An output level converter 14d for outputting an output level based on the calculation result of the ID calculator 14c. P
The ID calculation unit 14c compares the input steam pressure PV with the required steam pressure SP, and performs a PID calculation based on the comparison. That is, the PID calculation unit 14c performs the PID calculation using the following calculation expression (1).

MVPID = CPID (SP-PV) CPID = Kg {1+ (1 / Ti)} (1 + Td) / (1 + ηTd) (1) where Kg: proportional gain Ti: integration time Td: differentiation time η: In the equation (1), the PID parameter (K
g, Ti, Td), the proportional gain Kg indicates, for example, a ratio between the steam pressure PV at a certain point in time and the required steam pressure SP, and is a parameter for compensating for a compensation effect on a dead time characteristic and a time delay. The integration time Ti is a parameter for compensating an equilibrium point characteristic for relaxing characteristics of hunting of the output due to, for example, overshoot, and the differential time Td is, for example, a sudden change or a gradual change of the steam pressure PV. This is a parameter for realizing the corresponding delicate control.

Calculation result MVPID of PID calculation section 14c
Is, for example, in the range of 0 to 100%, and is output to the output level conversion unit 14d. In the present embodiment, for example, a steam boiler system in which the combustion state of each of the three boilers can be changed to three states of a high combustion state H, a low combustion state L, and a stop state S will be described. For example, the above three combustion states are defined by the following control states MV from the higher one with respect to the overall system output level MVPID which is the calculation result from the PID calculator 14c.

HHH → HHL → HHS → HLS → HSS
→ LSS → SSS Then, 0 to 100% of the MVPID is divided into seven, and the corresponding control state MV is mapped and assigned as follows.

[0014]

[Table 1]

The output level converter 14d stores the data mapped as shown in Table 1 in an internal memory,
The calculation result MVPID input from the calculation unit 14c determines the range of the divided data, and outputs a corresponding control state to each operation control unit 15 that controls the operation of each boiler 10. For example, the calculation result MVPID is 43-
In the range of 57%, the operation control unit 15 for controlling the operation of the first boiler receives the data indicating the control state H, and the operation control unit 15 for controlling the operation of the second boiler displays the control state L. Data indicating the control state S is output to the operation control unit 15 that controls the operation of the third boiler. When the calculation result MVPID is in the range of 15% to 29%, the operation control unit 15 for controlling the operation of the first and second boilers includes data indicating the control state H and the operation control of the third boiler. The operation control unit 15 outputs data indicating the control state L.

Each operation control unit 15 includes an output level conversion unit 1
The boiler 10 is driven by controlling the combustion state of the combustion unit 16 based on the data indicating the control state input from 4d. That is, in this embodiment, since the characteristics of the PID control are given, the control of the number of units by the group management of a plurality of boilers can be realized, and the static and dynamic characteristics of the control system constituted by the boiler and the pressure are logically determined. Can compensate.
As a result, in the present embodiment, it is possible to alleviate the unnecessary vertical movement of the vapor pressure and the occurrence of overshoot when the system is started.

In this embodiment, since the PID control characteristic is given, the integration operation is added, so that the equilibrium point characteristic is compensated and output hunting is prevented. Also,
In the present embodiment, since the parameters of the PID calculation unit can be changed, a configuration is possible in which fine adjustment corresponding to slightly different characteristics of each system is possible, and delicate control according to the situation can be realized. That is, since the fine adjustment is performed using the above parameters, a well-known adjustment rule can be applied to each unit control system, that is, an index for finely adjusting the control characteristics is given.

Further, in this embodiment, the control of the number
Since the control operation is performed, the memory capacity can be reduced as compared with the conventional table reference system, and the problem of hardware restrictions can be alleviated. In the present embodiment, the control of the number of units by the steam pressure has been described. However, the present invention is not limited to this, and it is needless to say that the present invention is similarly used for controlling the number of boilers by the steam flow rate.

FIG. 2 is a second embodiment showing a case where the system for controlling the number of installed devices according to the present invention is used for an absorption type water heater / heater installed in a building or the like. In the figure,
In the present embodiment, a plurality of chiller / hot water heaters 20 are installed in parallel, and hot water output from each chiller / heater is collected in a hot water collecting part 22 via each hot water pipe 21. Hot water collecting part 22
Is provided with a temperature sensor 23 constituting a detection unit of the present invention. The temperature sensor 23 detects a temperature PV which is a control amount of the present invention, and outputs the temperature PV to the number control device 24.
Since the number control device 24 has the same configuration as the number control device 14 shown in FIG. 1, detailed description is omitted. Is defined and assigned to a control state which can be changed to three states of a hot water state, a cold water state, and a flowing water stop state.

Each operation control unit 25 includes an output level conversion unit 2
The water flow 26 flowing through the catalyst is controlled based on the data indicating the control state input from 4d to drive the water heater / heater 20. As described above, also in this embodiment, since the characteristics of the PID control are given, it is possible to calculate an appropriate operation amount and realize the control of the number of units by the group management of the water heater / heater.

FIG. 3 is a third diagram showing a case where the system for controlling the number of installed devices according to the present invention is used for a hot water heater.
This is an example. In the figure, in the present embodiment, a plurality of hot water heaters 30 are installed in parallel, and hot water output from each hot water heater is collected in a hot water collecting unit 32 via each hot water pipe 31. The hot water collecting unit 32 is provided with a temperature sensor 33 constituting a detection unit of the present invention. The temperature sensor 33 detects a temperature PV which is a control amount of the present invention, and outputs the temperature PV to a unit control device 34. I have. The number control device 34
Has a configuration similar to that of the number control device 14 shown in FIG.
In d, MV is defined and assigned to a control state in which the state of the hot water temperature from the three hot water heaters can be changed to three states of a high temperature state, a low temperature state, and a stop state.

Each operation control unit 35 includes an output level conversion unit 3
The hot water temperature 36 is controlled based on the data indicating the control state input from 4d to drive the hot water heater 30. As described above, also in the present embodiment, since the characteristics of the PID control are given, it is possible to calculate an appropriate operation amount and realize the control of the number of hot water heaters by group management. The present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the present invention can also be used for controlling the number of burners for painting automobiles for controlling hot air and the number of air conditioners.

[0023]

As described above, in the present invention, a desired control amount is given to the detected control amount, a PID calculation is performed based on the comparison, and a continuous value of the operation amount as the calculation result is obtained. By converting to the output level of the number of installed devices, the number of installed devices can be controlled by group management. Therefore, the operation control of the installed devices is performed by PID control, and the optimal amount of operation is considered while considering the control amount fluctuation situation. Can be calculated.

[Brief description of the drawings]

FIG. 1 shows a system for controlling the number of installed devices according to the present invention.
It is a block diagram of the 1st Example which shows the case where it is used for the number control of boilers.

FIG. 2 shows a system for controlling the number of installed devices according to the present invention.
It is a block diagram of the 2nd Example which shows the case where it is used for an absorption-type water heater.

FIG. 3 shows a system for controlling the number of installed devices according to the present invention.
It is a block diagram of the 3rd Example which shows the case where it is used for a hot water heater.

[Explanation of symbols]

 Reference Signs List 10 Boiler 11 Steam pipe 12 Steam collecting unit 13 Pressure sensor 14, 24, 34 Number control device 14a, 24a, 34a PV input unit 14b, 24b, 34b SP input unit 14c, 24c, 34c PID calculation unit 14d, 24d, 34d Output Level conversion unit 15, 25, 35 Operation control unit 16 Combustion unit 20 Water cooler / warmer 21, 31 Hot water pipe 22, 32 Hot water collecting unit 23, 33 Temperature sensor 26 Flow rate 30 Hot water heater 36 Hot water temperature

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3L021 AA05 CA08 DA04 DA38 FA21 5H004 GA03 GA10 GB20 HA01 HA02 HA03 HB01 HB02 HB03 JA03 KA13 KB02 KB04 KB06

Claims (5)

[Claims] An operation control method of an installed device for controlling the operation of a plurality of installed devices and operating the required number of the installed devices, wherein a control amount common to the detected installed devices is given in advance. The operation amount for controlling the operation of the installed equipment is obtained by a comparison integral differentiation operation, and the continuous value of the obtained operation amount is converted into an output level for controlling the number of the installed equipment. A method for controlling the number of installed devices. 2. An operation control system for an installed device for controlling operation of a plurality of installed devices and operating the required number of the installed devices, wherein a detection unit for detecting a control amount common to the installed devices. A PID operation unit that compares a predetermined control amount given in advance with the detected control amount and determines an operation amount for operation-controlling the installed device by a proportional-integral-derivative operation; An output level conversion unit for converting a continuous value of the operation amount into an output level for controlling the number of the installed devices, the number of installed devices being controlled. 3. The system for controlling the number of installed equipment is used for controlling the number of boilers to be burned, wherein the detection unit detects a control amount common to the boilers, and the PID calculation unit burns the boilers. 3. An operation amount for control is determined by a proportional-integral-derivative operation, and the output level conversion unit converts a continuous value of the determined operation amount into an output level for controlling the number of the boilers. The system for controlling the number of installed devices described in 1. 4. The PID calculation unit 14c calculates: MVPID = CPID (SP-PV) CPID = Kg {1+ (1 / Ti)} (1 + Td) / (1
4. The system for controlling the number of installed devices according to claim 2, wherein the PID calculation is performed using an equation of Kg: proportional gain Ti: integration time Td: differentiation time η: constant. 5. The system according to claim 4, wherein the PID calculation unit performs calculation by changing each parameter of the calculation formula according to characteristics of the system.