JPS61159007A - Automatic number control system of boiler - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of an automatic boiler number control method that determines the required number of boilers to be fired in accordance with load fluctuations in a multi-can installation system and automatically follows the load. It is something.

In order to control multiple boilers, the common method is to use one or two pressure limiters, but with this method, all boilers or multiple boilers are operated at the same time, so all boilers in operation are under low load. In addition to the drawback of inefficient usage when the time and load fluctuations are small, not only do peak currents overlap at startup, which impedes protection coordination on the power supply side, but also because ignition is the same, If stacks are used as stacks, packfires etc. will occur.

In order to improve this situation, each boiler should be equipped with a pressure limiter, each boiler should be shut down in an orderly manner as the load decreases, and all boilers in operation should be operated at high loads for maximum efficiency. If the conventional automatic control system were to be used to control this, the larger the number of boilers, the more difficult it would be because of the large fluctuations in steam pressure or load. Also, the order in which boilers are started and stopped is determined by the value of the pressure limiter of each boiler, so some boilers may turn on and off frequently depending on the load. Changing this order is necessary to set the steam pressure. There are drawbacks such as the need to repeat the procedure for each boiler and it is not easy to do, and it is possible to avoid the inconvenience of having to operate the pressure limiter each time when stopping the boiler or restarting the boiler at random. I can't.

This invention was devised to eliminate the above-mentioned drawbacks. The operating order can be easily changed by dial operation, and the steam pressure is set using a single pressure regulator installed in the steam header, so pressure fluctuations can be avoided. The width can be set small, and by installing multiple boilers for three-position control, each boiler is controlled in three stages: stop, low combustion, and high combustion, so the system as a whole can handle small load fluctuations. This will help you respond more efficiently.

An embodiment of the present invention will be described below regarding a case where the number of boilers is controlled to four.

As shown in Figure 1, attach a pressure regulator to the steam header and set the required steam pressure (control pressure).

A similar type of pressure regulator works to replace steam pressure fluctuations with linear resistance changes, so this pressure regulator transmits the steam pressure as an electrically linear signal to the unit control unit. This signal is sent to the second pressure detector with the configuration shown in Figure 3.
It detects which of the nine stages shown in the figure. In other words, if the pressure inside the steam header is near the lower limit, the load is assumed to be large and all four units are directed to high combustion operation.

As the steam pressure rises, the number of combustion boilers is reduced by half (every half stage) to move to a low combustion state, and when the steam pressure reaches the upper limit, all boilers stop combustion. . On the other hand, if the steam pressure decreases, it is assumed that the load is increasing, that is, the number of combustion units is insufficient, and the amount is increased by half, and the steam pressure and the required number of combustion units are balanced so that they are appropriate as set, and unnecessary boilers are removed. prevent combustion and reduce loss.

Explaining Figure 3, the circuit configuration shown in the figure is such that the pressure detector detects how many units should be burned based on the steam pressure signal obtained from the pressure regulator, and generates a combustion signal. There is. This signal along with the signal from the delay circuit is
Sent to ND circuit.

In other words, this delay circuit is to prevent simultaneous ignition, and when igniting, it sends a signal to the low combustion signal generation section only when there is a signal from both the pressure detection section and the delay circuit, so that one unit at a time always switches to combustion. . A signal is directly sent from the pressure detection section to the high combustion signal generation section. A number controller consisting of at least a pressure detection section, a delay circuit, a low combustion signal generation section, and a high combustion signal generation section shown in the figure from the pressure regulator performs logical operations to determine how many units to burn and selects the combustion order. switch SW
1 to SW4 (sw is not shown), and the starting order of each boiler is set using the switches SW1 to SWa. In this case, switch SWl is set to 1
Set switch SW2 to number 2, switch SW
If 3 is set to No. 3 and switch SW & is set to No. 4, relay x 2 becomes No. 2, relay x 6 becomes No. 8.

The wiring with each boiler is as shown in Figure 4, connecting the contacts of relays x1 to x8 in series to the steam pressure limiters PHL to PHa and PLL to PLa of each boiler (PH1 to PHa
': positive pressure limiter on the high setting side, PL1 to PLa: steam pressure limiter on the low setting side).

Switch 5Ws = SWs causes each boiler to burn independently (controlled by the steam pressure limiter attached to the boiler)
This is a switch for making three selections for each boiler: when combustion is stopped individually, when combustion is controlled by a multi-unit controller.

When controlling the number of units, the switches S W s to S W s are set to the combustion control side by the number controller. In addition, the steam pressure controllers PH1 to PF(a) and PLt to PL4 are set higher than the pressure setting of the pressure regulator, and the boiler is turned on.
OnN is performed using a signal from the number controller.

As explained above, the present invention has the following effects compared to the conventional multi-can installation by incorporating automatic number control into the multi-can installation system.

(b) The operating order of the boilers can be changed freely.

In order to achieve the same effect as tire rotation in a car, the operating order of the boilers can be easily changed by operating a dial, allowing for systematic boiler operation management. Therefore, the life of the entire boiler can be extended.

(b) Maintain efficient operation.

It is easy to set the combustion stage at the control pressure, and by using multiple cans together (9 stages for 4 units), it is possible to appropriately respond to small load fluctuations, and losses caused by turning the boiler on and off are prevented to the maximum. Therefore, efficient operation of the boiler is possible.Also, even if it is necessary to continuously operate the boiler at the lowest load due to load conditions, the minimum number of boilers will be automatically operated, so there is no waste (hunting is avoided). It can be prevented.)(
c) Pressure fluctuations can be reduced.

Since it is controlled by one pressure regulator, it is possible to minimize pressure fluctuations due to load fluctuations.

(d) Control operations can be performed in accordance with load fluctuations.

When load fluctuations are severe or slow, the 1IIIWJ operation can be easily changed depending on the situation at the site.

(E) It is safe because it uses a power reset method.

If there is a power outage, there is no need to worry. Since it is a power reset method, it will start up after going down to the operating order according to the settings.

[Brief explanation of the drawing]

FIG. 1 is a flow sheet showing an embodiment of the present invention. FIG. 2 is an explanatory diagram showing the relationship between steam pressure and the number of boilers fired. 3 and 4 are sequences showing an embodiment of the present invention. Xl...NQ 1 Boiler low combustion relay x 2
...h01 boiler high combustion relay x 3...
...Na 2 boiler low combustion relay x4...
・NQ 2 Boiler high combustion relay Xs...N
α3 boiler low combustion relay X6...NQ 3
Relay for boiler high combustion Xr...Nα4 Relay for boiler low combustion SW2...Nα2 Boiler combustion order selection switch SW3......~o3
Boiler combustion order selection switch SW 4...
Nα4 boiler combustion order selection switch SW s...
...No.1 Boiler switch SWa...Nu2 Boiler switch SW7...No.3
Boiler switch S W s...Nα4 Boiler switch PH1...No, 1 Boiler high setting side steam pressure limiter PL1...Na 1 Boiler low setting side steam pressure limiter PH+ ...1102
Boiler high setting side steam pressure limiter PL2...
α2 boiler low setting side steam pressure limiter PH3...
・No. 3 Boiler high setting side steam pressure limiter PL3・
...Nα3 boiler low setting side steam pressure limiter,
P H4...No, 4 Boiler High Setting Side Steam Pressure Limiter Patent Applicant Youra Kogyo Co., Ltd. Drawing engraving (no changes to the content) Unit P system? yl equipment body No. 2, 3, 4 Procedures Amendments January 1, 1985/Q] Patent axis 2 submitted on October 4, 1985, title of invention: Boiler automatic number control system 3 , Relationship with the case of the person making the amendment Patent applicant address 7 Horie-cho, Matsuyama-shi, Ehime (voluntary) 5. Subject of amendment
1 procedure amendment i October 1, 1985

Claims (1)

[Claims] In a multi-can installation system, a pressure regulator is provided in the steam header, and a number controller comprising a pressure detection section, a combustion signal generation section, a delay circuit, and a relay drive section is connected to the pressure regulator. By installing the same number of combustion order setting switches as the number of boilers and having the same number of switching contacts as the number of boilers, and connecting the switching contacts to the combustion signal generating section and the common contacts to the relay driving section, An automatic boiler number control system, characterized in that a required number of boilers are operated according to the load condition ascertained inside the steam header, and the operating order of the boilers is controlled via the combustion order setting switch.