JPH0616242Y2 - Boiler load distribution control device - Google Patents

Description

[Detailed Description of the Invention] [Field of Use of the Invention] The present invention relates to a load distribution control device for boilers that are operated in parallel, and particularly to a boiler that depressurizes high-pressure steam generated in the boiler and uses it as process steam for other processes The present invention relates to a load distribution control device.

[Background of the invention]

Generally, when operating multiple boilers in parallel, the outlets of the boilers are connected by heading, the pressure at the heading is detected, and for example, the fuel amount and air amount of each boiler are adjusted and extracted from the heading. The pressure of the reduced pressure steam is controlled.

FIG. 3 is a system diagram of a load distribution control device in a conventional boiler.

In FIG. 3, 1 and 2 are boilers, 3 and 4 are boilers 1,
2 is a fuel supply system for supplying fuel A to 5, 2 and 6 are fuel amount controllers for controlling the amount of fuel in the fuel supply systems 3 and 4, and 7 and 8 are air supplies for supplying combustion air B to the boilers 1 and 2. system,
Reference numerals 9 and 10 are air amount controllers for controlling the air amounts of the air supply systems 7 and 8, 11 and 12 are communication conduits for supplying the high-pressure steam C of the boilers 1 and 2, 13 and 14 are pressure reducing valves, and 15 and 16 Is a reduced pressure steam line for supplying reduced pressure steam D, 17 is a heading pipe, 18 is a steam discharge line for supplying process steam E, 19 is a pressure detector, 20 is a pressure signal,
Reference numeral 21 is a pressure controller, 22 and 23 are load distributors, 24 and 25 are load distribution command signals, and 26 and 27 are pressure reducing valve controllers.

In such a configuration, the pressure signal 20 from the header 17 is converted into load distribution command signals 24 and 25 by the load distributors 22 and 23,
By the load distribution command signals 24 and 25, the fuel amount and the air amount of the boilers 1 and 2 are changed to the fuel amount controllers 5 and 6 and the air amount controller 9,
It was controlled by 10 to control the heat input to the boilers 1 and 2 in response to the load distribution command signals 24 and 25.

However, the pressure reducing valves 13 and 14 arranged between the boilers 1 and 2 and the header 17 are controlled by the pressure reducing valve controllers 26 and 27 regardless of the load distribution command signals 24 and 25. Boiler with high pressure setting or pressure reducing valve controller 26, 27
The more sensitive boiler will take on more load changes faster.

Therefore, the heat input amount change corresponding to the load distribution command signals 24 and 25 does not become the generated steam amount corresponding to the load distribution command signals 24 and 25, and the heat input amount becomes the heat storage amount change of the boilers 1 and 2 and the boiler 1 2, the pressure of the generated steam changes.

Therefore, when a plurality of boilers 1 and 2 are operated in parallel, the load cannot be evenly distributed to the boilers 1 and 2.

[Purpose of device]

The present invention is intended to eliminate such conventional drawbacks,
It is an object of the present invention to provide a load distribution control device capable of performing load distribution according to characteristics such as sensitivity of a pressure reducing valve, and further capable of performing load distribution evenly.

[Outline of device]

In order to achieve the above-mentioned object, the present invention provides an arithmetic unit between the load distributor and the pressure reducing valve to provide a load distribution command signal from the load distributor and a correction signal based on characteristics such as sensitivity of the pressure reducing valve. The pressure reducing valve is controlled by the calculated load distribution signal.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are system diagrams of a load distribution control device according to an embodiment of the present invention.

In FIGS. 1 and 2, reference numerals 1 to 25 are the same as conventional ones.

28 and 29 are load distribution signals for controlling the pressure reducing valves 13 and 14, 30, 31 are high pressure steam pressure detectors, 32 and 33 are high pressure steam pressure controllers, 34,
Reference numeral 35 is a reduced pressure steam flow meter, 36 and 37 are command signals, 38 and 39 are correction signals, and 40 and 41 are calculators.

In such a configuration, as shown in FIG. 1, the load distributor 2
The load distribution signals 28, 29 are set to the load distribution command signals 24, 25 from 2, 23 by adding the correction signals 38, 39 by the calculators 40, 41 according to the characteristics such as the sensitivity of the pressure reducing valves 13, 14. The load distribution signals 28 and 29 directly control the pressure reducing valves 13 and 14, and the steam pressures of the communication lines 11 and 12 are detected by the high pressure steam pressure detectors 30 and 31. Command signal from 36,
37 controls the fuel amount and the air amount by the fuel amount controllers 5 and 6 and the air amount controllers 9 and 10 of the boilers 1 and 2.

In this way, the load distribution command signals 24 and 25 are artificially distributed with the correction signals 38 and 39 in accordance with the characteristics such as the sensitivity of the pressure reducing valves 13 and 14 to obtain the desired load distribution signals 28 and 29, and the pressure reducing valve 13 is obtained. , 14 are controlled, the control change of the pressure reducing valves 13, 14 immediately appears as the pressure change of the high-pressure steam C, and the load distribution to the boilers 1, 2 can be performed quickly.

When the pressure reducing valves 13 and 14 are controlled by the load distribution signals 28 and 29, the pressure of the high pressure steam C changes, and the high pressure steam pressure detectors 30 and 31 detect this pressure change, and the high pressure steam pressure controller 3
The command signals 36, 37 from 2, 33 change and the fuel amount controller 5,
6 and the air volume controllers 9 and 10 are adjusted to balance the boilers 1 and 2.

In this way, the pressure of the pressure reducing steam D at the outlets of the pressure reducing valves 13, 14 which is the original purpose of the pressure reducing valves 13, 14 is kept constant irrespective of the change of the flow rate so that the pressure of the header 17 becomes constant. Since the commands of the pressure detector 19 and the pressure controller 21 are given to the pressure reducing valves 13 and 14 through the load distributors 22 and 23, the process steam E of the steam discharge line 18 is more suitable for the purpose of use than the prior art. It can control the steam pressure.

FIG. 2 shows another embodiment. The difference from FIG. 1 is that in FIG. 1, the correction signal 38 is adjusted in accordance with the characteristics such as sensitivity of the pressure reducing valves 13, 14. , 39 and load distribution command signals 24, 25 are added by the calculators 40, 41 to load distribution signals 28, 29.
Then, the pressure reducing valves 13 and 14 were controlled by the load distributing signals 28 and 29 to perform the load distribution. In the case of FIG. 2, the pressure reducing steam pipes 15 and 16 are provided with the pressure reducing steam flow meters 34 and 35, respectively. The reduced pressure steam flow rate signals (correction signals) 38, 39 from these reduced pressure steam flow meters 34, 35
The load distribution command signals 24 and 25 are calculated by the calculators 40 and 41 into load distribution signals 28 and 29, and the pressure reducing valves 13 and 14 are controlled by the load distribution signals 28 and 29.

In this way, the load distribution signals 28 and 29 are calculated with the correction signals 38 and 39 in consideration of the characteristics such as the sensitivity of the pressure reducing valves 13 and 14, and the pressure reducing valves 13 and 14 are controlled by the load distribution signals 28 and 29. So
It is possible to perform reliable load distribution control.

[Effect of device]

The present invention provides an arithmetic unit between the load distributor and the pressure reducing valve, and controls the pressure reducing valve by the load distribution command signal from the load distributor and the load distribution signal that calculates the correction signal based on the characteristics such as sensitivity of the pressure reducing valve. Since the control is performed, the load can be distributed according to the characteristics such as the sensitivity of the pressure reducing valve, and the load can be evenly distributed.

[Brief description of drawings]

1 and 2 are system diagrams of a boiler load distribution control device according to an embodiment of the present invention, and FIG. 3 is a system diagram of a conventional boiler load distribution control device. 1, 2 ... Boiler, 13, 14 ... Pressure reducing valve, 17 ... Heading, 2
0 ... pressure signal, 22, 23 ... load distributor, 24, 25 ... load distribution command signal, 28, 29 ... load distribution signal, 38, 39 ... correction signal, 40, 41 ... calculator.

Claims (1)

[Scope of utility model registration request] 1. A plurality of boiler outlets that are operated in parallel are connected to each other via a pressure reducing valve by heading, and a pressure signal from the heading is converted into a load distribution command signal by a load distributor to control each boiler. In this case, an arithmetic unit is provided between the load distributor and the pressure reducing valve, and a load distribution command signal from the load distributor and a correction signal based on characteristics such as sensitivity of the pressure reducing valve are input to the arithmetic unit. A load distribution control device for a boiler, characterized in that the pressure reducing valve is controlled by a load distribution signal calculated by the above.