JPS5936162B2 - Steam boiler operating system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steam boiler operating system.

As shown in FIG. 1, a plurality of boilers la, lb.

The method of connecting 1c to users 2a and 2b and operating them in parallel has been conventionally used, but this tends to cause situations such as the evaporation amount of each boiler not being able to follow load fluctuations. There was a drawback that the evaporation amount interfered, resulting in instability, and the operating efficiency of the boiler was significantly reduced.

The present invention has been made in view of these conventional problems, and its primary objective is to prevent interference between boilers and to reliably control the steam flow rate.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. The embodiment shown in FIG. 2 is a case where one high pressure boiler 10a and two low pressure boilers 10b and 10c are operated in parallel. The high pressure boiler 10a is connected to a header 12 leading to a user 11 via steam supply pipes 13a, 13b and a steam accumulator 14, and is connected to a low pressure boiler 10b.

10c is connected directly to the header 12 via steam supply pipes 15,16.

Flow rate detectors 17a to 17C for detecting the steam flow rate from the boiler and flow rate valves 18a to 18c for controlling the steam flow rate are connected to each of the steam supply pipes 13a and 15.16, respectively, and each of the flow rate valves 18a to 18c The flow rate indication adjustment devices 19a to 19C that control the flow rate transmitters 20a to
20c and pressure detector 21, respectively.

The pressure detection device 21 includes a steam accumulator 14
It detects the level of the internal pressure of the accumulator 14 that fluctuates according to load fluctuations, and also detects the slope of the fluctuation curve by comparing the magnitude of the pressure at every minute time. Flow rate valves 18a to 18c are controlled via flow rate indicating and adjusting devices 19a to 19c when the relationship is determined to be constant.

In addition, in the figure, 22 and 23 are a pressure valve and its pressure indicating adjustment device for keeping the pressure on the secondary side of the accumulator 14 constant, and 24 is a device for controlling the total steam flow rate based on the flow rate signal from each flow rate detector 17a to 17c. This is a flow rate adder for detection.

Now, in the operating state of each boiler 10a to 10c,
The steam generated in the high-pressure boiler 10a flows into the accumulator 14 via the steam supply pipe 13a, where it is accumulated as saturated hot water.
Steam self-evaporated within is supplied through the steam supply pipe 13b.

On the other hand, steam from the low pressure boilers 10b and 10c is directly supplied to the user 11 through steam supply pipes 15.16.

In this case, each steam supply pipe 13a. The flow rate of steam flowing through 15.16 is detected by the flow rate detectors 17a to 17c, respectively, and the flow rate valves 182 to 18c are controlled by the flow rate indicating adjustment device 1 according to the flow rate signals from the flow rate transmitters 202 to 20c.
By opening and closing 9a to 19C, the set flow rate is maintained.

In this state, if the amount of steam used increases due to a load change in the user 11, it becomes necessary to increase the amount of steam supplied accordingly, but the low pressure boiler 10b.

Since the flow rate from boiler 10c is maintained at the set flow rate by flow valves 18b and 18c, these boilers 10b and 1
0c does not independently follow load fluctuations and increase the amount of evaporation, so the load fluctuations are absorbed by the accumulator 14.

When the load fluctuation is absorbed by the accumulator 14, the internal pressure Ap of the accumulator 14 gradually decreases, and as shown in FIG. indicates a negative value (between a and b), this is detected by the pressure detection device 21 and a pressure signal is sent to each flow rate indicating adjustment device 19a to 19.
C, and a signal to open each of the flow valves 18a to 18C is issued at the same time.

Therefore, each flow valve 18a-18c is gradually opened, and the steam flow rate from each boiler 10a-10c is gradually increased.

As a result, the internal pressure of the accumulator 14 gradually increases and returns to a normal value higher than the low pressure level.

Conversely, when the load decreases, it is similarly absorbed by the accumulator 14, so that the accumulator 1
The internal pressure Ap of No. 4 increases, but if the internal pressure Ap rises higher than the high pressure level H and its slope is positive (
c-d), each flow valve 18a to 18C is throttled by the pressure signal from the pressure detector 21, and each boiler 10a to
The amount of steam supplied from 10C is restricted, and the internal pressure A p of the accumulator 14 returns to its normal value.

As a result, each of the boilers 10a to 10c can be controlled according to the ratio of their rated evaporation amounts while following current load fluctuations, and there is no mutual interference in evaporation amount between the boilers.

As detailed above, according to the present invention, in a boiler system having a boiler connected to a user via a steam accumulator and a boiler directly connected to a user, the flow rate valve in each boiler is controlled based on the internal pressure of the steam accumulator. Since they are controlled simultaneously, each boiler can be controlled according to the ratio of their rated evaporation amounts while following the current load fluctuations.Moreover, mutual interference between each boiler can be prevented and the operating efficiency can be significantly increased. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional boiler system, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a diagram showing changes in the internal pressure of an accumulator. 10a-10c...Boiler, 11...
User, 13a, 15.16... Steam supply pipe,
14...Steam accumulator, 18a-1
8c...Flow rate valve, 21...Pressure detection device.

Claims (1)

[Claims] 1 A boiler connected to the user via a steam accumulator and a boiler directly connected to the user are provided, and a flow valve for controlling the steam flow rate is connected to the steam supply pipe from each boiler, and the steam flow rate is adjusted according to load fluctuations at the user. A steam boiler operating system characterized in that a pressure detection device detects the level and gradient of the internal pressure of an accumulator that fluctuates over time, and simultaneously controls flow valves in each boiler using pressure signals from the pressure detection device.