JPH06147402A - Boiler combustion amount controller - Google Patents

Abstract

PURPOSE:To improve energy saving, prevention of extreme reduction of steam pressure, and long life of a facility. CONSTITUTION:When steam pressure P falls lower than the fixed pressure P2, solenoid valves 20, 38, 21 are opened, and fuel oil is injected into a combustion chamber 3 from burner nozzles 6, 37, 7 (100% combustion). Contrarily, when the steam pressure P rises higher than the fixed pressure P2 and also falls lower than pressure P3, the solenoid valves 20, 38 are opened and the solenoid valve 21 is closed, and fuel oil is injected into the combustion chamber 3 from the burner nozzles 6, 37 (approximately 65% combustion). Moreover, when the steam pressure P rises higher than the pressure P3 and also falls lower than the pressure P1, the solenoid valve 10 is opened and the solenoid valves 38, 21 are closed, and fuel oil is injected into the combustion chamber 3 from the burner nozzle 6 (approximately 30% combustion). While, when the steam pressure P rises higher than the pressure P1, the whole solenoid valves 20, 38, 21 are closed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiler combustion amount control device.

[0002]

2. Description of the Related Art For example, a small once-through boiler is conventionally used as a small-capacity boiler having a steam generation amount of about 0.5 to 5 t / h. As a combustion method of such a once-through boiler, high combustion (100%) is used. So-called three-position control of combustion, low combustion (approximately 50% combustion), stop (0% combustion) is adopted.

An example of such a once-through boiler that performs such three-position control is shown in FIG. 5, for example, and the once-through boiler uses oil such as heavy oil as fuel.

In FIG. 5, reference numeral 1 denotes a boiler main body, which is vertically oriented and vertically erected at a predetermined interval in the circumferential direction, and is surrounded by a plurality of heating pipes 2. The boiler body includes a combustion chamber 3 formed in the internal space, an annular lower header 4 connected to the lower portion of the heating pipe 2, and an annular upper header 5 connected to the upper portion of the heating pipe 2. A plurality of burner nozzles 6 and 7 capable of injecting fuel oil into the combustion chamber 3 are vertically installed in a space surrounded by the upper header 5.

Reference numeral 8 denotes a water supply pipe connected to the lower pipe drawer. The water supply pipe 8 is provided with a water feed pump 9 and a lower pipe drawer 4 adapted to supply water to the lower pipe drawer 4 of the boiler body 1.
Check valve 1 to prevent water from flowing backward from the water supply pump 9
It has 0 and 10.

Reference numeral 11 denotes a steam separator, the upper side of the steam separator 11 and the upper surface of the upper header 5 are connected by a steam pipe 12, and the bottom of the steam separator 11 and the lower header 4 are connected. It is connected to the side of by the downcomer 13.

Reference numeral 14 is a water level detecting container used for detecting the level (water level) of the water in the heating pipe 2 of the boiler body 1. One end of the water level detecting container 14 is connected to the bottom portion and the upper portion thereof. The other ends of the communicating tubes 15a and 15b are connected to the lower header 4 or the upper header 5. Further, in the water level detecting container 14, five water level detecting electrode rods 16a, 16b, 16c, 16d, 16f having different lengths are inserted, and each water level detecting electrode rod 16a, 16b, 16c, 1 is inserted.
The lower end positions of 6d and 16f have different heights and 16
It is arranged so that the lower end position becomes higher in the order of a, 16b, 16c, 16d, 16f. Further, the water levels Ha, Hb, Hc, Hd, Hf (Ha <Hb <detected by the water level detection electrode rods 16a, 16b, 16c, 16d, 16f).
Hc <Hd <Hf) can be given to the water level control device 17 as a signal.

Reference numerals 18 and 19 denote fuel oil pipes connected to the burner nozzles 6 and 7, respectively, and solenoid valves 20 and 21 are connected to the fuel oil pipes 18 and 19, respectively. A fuel oil pipe 22 is connected to the fuel oil pipes 18 and 19, and a fuel oil pump 23 is connected to the fuel oil pipe 22.

Reference numerals 24 and 25 denote pressure switches connected to the steam pipe 12, and when the pressure P of the steam flowing through the steam pipe 12 falls below a preset pressure P ₂ , the pressure switch 25 causes the combustion control device 26 to operate. so it can give the operation instruction V ₂ to which, from the pressure switch 24 is higher than the pressure P ₂ lower than the pressure P ₁ of the pressure P is set in advance through the steam pipe 12 to the combustion control device 26 Operation command V ₁
Is to be given. The pressure switch 2
The relationship between the pressures P ₁ and P ₂ set to 4, 25 is P ₁ > P ₂ .

From the combustion control device 26, the operation command V ₁ ,
Alternatively, V ₂ can be given to the water level control device 17 and a start / stop command V ₃ can be given to the fuel oil pump 23, and further open commands V ₅ , V ₆ can be given to the solenoid valve 2.
It can be given to 0 and 21. Further, the water level control device 17 can give a start / stop command V ₄ to the water supply pump 9.

In the once-through boiler, for example, when the pressure P of the steam flowing through the steam pipe 12 becomes lower than a preset pressure P ₂ , an operation command V ₂ is given from the pressure switch 25 to the combustion control device 26 (in this case, The operation command V ₁ is not output from the pressure switch 24), and the solenoid valves 20 and 21 are opened by the opening commands V ₅ and V ₆ from the combustion control device 26. Therefore, the fuel oil delivered from the fuel oil pump 23 passes through the fuel oil pipe 22, the fuel oil pipes 18 and 19 and the solenoid valves 20 and 21 provided in the middle of the fuel oil pipe 22, and enters the combustion chamber 3 from the burner nozzles 6 and 7. It is injected and burned (100% combustion), and combustion gas is generated.

When the pressure P of the steam flowing through the steam pipe 12 becomes higher than the preset pressure P _{2 and} lower than P ₁ , the pressure switch 24 gives an operation command V ₁ to the combustion control device 26 ( The operation command V ₂ is not given from the pressure switch 25), and the solenoid valve 20 is opened by the open command V ₅ from the combustion control device 26, but the solenoid valve 21 is opened by the open command V 2.
₆ is not given and the solenoid valve 21 closes. Therefore, the fuel oil passes through the fuel oil pipe 22, the fuel oil pipe 18, and the electromagnetic valve 20 provided in the middle thereof, and is injected into the combustion chamber 3 from the burner nozzle 6 and burned (approximately 50% combustion).

When the pressure P of the steam flowing through the steam pipe 12 is higher than the preset pressure P ₁ , the pressure switch 2
The operation commands V ₁ and V ₂ are not given to the combustion control device 26 from 4 and 25, and the opening commands V ₅ and V ₆ are not output from the combustion control device 26. Therefore, the solenoid valves 20 and 21 are closed,
Injection of fuel oil from the burner nozzles 6 and 7 is stopped (0
%combustion). At this time, the combustion control device 26 to the water level control device 1
Since the operation commands V ₁ and V ₂ are not given to 7, the water supply pump 9 is stopped by the start / stop command V ₄ from the water level control device 17. Further, the fuel oil pump 23 is stopped by the start / stop command V ₃ from the combustion control device 26.

On the other hand, in the case of 100% combustion and approximately 50% combustion, the water introduced by the water supply pump 9 into the lower header 4 via the water supply pipe 8 rises in the heating pipe 2 from the lower header 4 and burns. It is heated by the combustion gas generated by the combustion of the fuel oil in the chamber 3, becomes steam, enters the steam pipe 12 from the upper header 5, is introduced into the steam separator 11 from the steam pipe 12, and the steam separator 11 The steam from which the water has been removed is sent to the steam destination and consumed, and the water separated by the steam separator 11 is returned from the downcomer 13 to the lower header 4.

Further, during the above three position control, the boiler body 1
The water level in the heating pipe 2 is simultaneously controlled.

For example, at the time of 100% combustion, the water level in the water level detecting container 14 must be positioned between Hb and Hc. Therefore, for example, the water level is between Hc and Hd in the water level detection container 14 at the time of 100% combustion, and signals are given to the water level control device 17 from the water level detection electrode rods 16a, 16b, 16c. In this case, the water supply pump 9 is stopped by the start / stop command V ₄ given to the water supply pump 9 from the water level control device 17.

The operation command V ₂ is given from the combustion control device 26 to the water level control device 17 by 100% combustion, and at the same time the water level in the heating pipe 2 of the boiler main body 1 and the water level in the water level detecting container 14 is lowered, and the water level is lowered. Falls below Hb, and when the water level is detected only by the water level detecting electrode rod 16a, the water supply pump 9 is started by the start / stop command V ₄ given to the water supply pump 9 from the water level control device 17,
Water is sent to the lower header 4 of the boiler body 1 by the water supply pump 9. When the water level rises and water is detected by the water level detecting electrode rods 16a, 16b, 16c, the water supply pump 9 is stopped again by the start / stop command V ₄ .

At about 50% combustion, the water level detecting container 1
Since the water level in 4 must be positioned between Hc and Hd, the water level detecting electrode rods 16a, 16b,
When water is detected by 16c and 16d, the water supply pump 9 is stopped, the water level is lowered, and the water level detection electrode rod 1
6a, 16b and when the combustion control device 26 gives an operation command V ₁ to the water level control device 17, the water supply pump 9 is started, the water level rises, and the water level detection electrode rod 16a, When it comes to be detected by 16b and 16c, the water feed pump 9 is stopped again.

The water level detecting electrode rods 16a and 16f are provided for safety, and the water level detecting electrode rod 16a is provided.
When water is not detected even by the above, or when water is also detected by the water level detecting electrode rod 16f, the operation of the once-through boiler is stopped.

The water level in the heating pipe 2 of the boiler body 1 is controlled to different heights depending on the combustion state corresponding to the boiler load for the following reasons. That is, the water level for obtaining good dryness of steam varies depending on the boiler load, as shown in region A of FIG. 7, and when the boiler load is high, a large amount of steam is generated unless the water level is lowered. This is because there is a risk that moisture will be mixed and the steam dryness will decrease, and if the boiler load is low, the temperature of the heating pipe 2 will become too high unless the water level is raised. In FIG. 7, an area B above the area A is a steam dryness deterioration area, an area C below the area A is a heating tube temperature rising area, and the heights of the black frames X ₁ and X ₂ correspond to the boiler load. Burned state is 100%, about 50%
The control range of the water level in the case of is shown.

Another example of the once-through boiler which performs three-position control is shown in FIG. 6, for example, in which gas is used as fuel. In the figure, the same components as those shown in FIG. 5 are designated by the same reference numerals.

In FIG. 6, reference numeral 27 denotes a burner gun vertically mounted in a space surrounded by the upper header 5 of the boiler body 1. The burner gun 27 is connected to the tip of a fuel gas pipe 28. The rear ends of the fuel gas pipes 28 are connected to the front ends of the fuel gas pipes 29 and 30 arranged in parallel with each other, and the rear ends of the fuel gas pipes 29 and 30 are connected to the fuel gas pipe 31. In addition, the fuel gas pipe 29 has an Oriifuisu 32,
Electromagnetic valves 33 are connected to the fuel gas pipe 30, and shutoff valves 34 and 35 and a pressure regulating valve 36 are sequentially connected to the fuel gas pipe 31 from the upstream side to the downstream side in the flow direction D.

Further, the open command V ₇ is an open command given from the combustion control device 26 to the solenoid valve 33, and V ₈ and V ₉ are the combustion control device 26.
Is an open command given to the shut-off valves 34, 35 from.

In such a once-through boiler, for example, the steam pipe 12
When the pressure P of the steam flowing through the combustion chamber becomes lower than a preset pressure P ₂ , an operation command V ₂ is given from the pressure switch 25 to the combustion control device 26, and the opening commands V ₈ , V ₉ , from the combustion control device 26 are given. Shut-off valves 34, 35, solenoid valve 33 by V ₇
Opens. Therefore, the fuel gas fed from the upstream side of the fuel gas pipe 31 is provided in the fuel gas pipe 31 and the valves 34, 35, 36 provided in the middle portion thereof, the fuel gas pipe 29 and the middle portion thereof. The burner gun 27 injects the fuel into the combustion chamber 3 and burns (100% combustion), passing through the fuel cell 32, the fuel gas pipe 30, the electromagnetic valve 33 provided in the middle thereof, and the fuel gas pipe 28.

When the pressure P of the steam flowing through the steam pipe 12 is higher than the preset pressure P _{2 and} lower than the pressure P ₁ ,
Operation command V ₁ from the pressure switch 24 to the combustion control device 26
Is given, and the solenoid valve 33 is closed by the open command V ₇ from the combustion control device 26. Therefore, the fuel gas is supplied to the fuel gas pipe 31 and the valves 34, 35,
36, a fuel gas pipe 29, an oil filter 32 provided in the middle thereof, and a fuel gas pipe 28, and a burner gun 27.
Is injected into the combustion chamber 3 to burn (approximately 50% combustion).

When the pressure of the steam flowing through the steam pipe 12 is higher than the preset pressure P ₁ , the pressure switch 2
Operation commands V ₁ and V ₂ are not given to the combustion control device 26 from Nos. 4 and 25, and an opening command V ₈ from the combustion control device 26 is given.
V ₉ and V ₇ are not output. Therefore, the shutoff valves 34, 35
Is closed, and the fuel gas injection from the burner gun 27 is stopped (0% combustion). At this time, the water supply pump 9 is stopped by the start / stop command V ₄ from the water level control device 17.

The control of the water level in the heating pipe 2 in the above three-position control is performed in the same manner as in the case of FIG.

[0028]

As a result of investigating the operating condition of the once-through boiler shown in FIGS. 5 and 6, 100% combustion × operating time, 50% combustion × operating time, 0% combustion × operating time are all summed up. It was found that the total load average obtained by dividing the load by the total operating time was about 40%. However, in the case of the above-mentioned three-position control, the combustion amount when the boiler has low combustion is about 4
It is about 5 to 50%, and as a result, most boilers are repeatedly operated and stopped frequently (30 to 50% per hour).
Times). When the boiler is repeatedly operated and stopped,
For safety reasons, it is necessary to perform post-purge every time it is stopped and pre-purge each time it is started. The post-purge and pre-purge are performed by sending indoor air from the combustion chamber 3 to the exhaust stack by a ventilator. Therefore, at the time of post-purge and pre-purge, the heat accumulated in the boiler body 1 and the system through which the combustion gas passes is exhausted to the atmosphere from the exhaust stack by being entrained by air and wasted.

Further, even if the steam consumption rapidly increases and the steam pressure drops during the boiler stoppage, post-purge, and pre-purge, the burner nozzles 6 and 7 and the burner gun 27 are not immediately ignited and steam is generated. There will be a time delay before this happens. For this reason, the pressure of the steam remaining in the boiler main body 1 falls too low, and it takes time until steam of a predetermined pressure is obtained, resulting in deterioration of steam productivity.

Further, since the combustion is stopped every time the boiler is stopped, the boiler body 1 and other devices are frequently heated or repeatedly not heated, and as a result, the number of times of repeated thermal stress increases and Since auxiliary machinery also frequently starts and stops, the life of the boiler equipment may be shortened.

In view of the above situation, the present invention reduces wasteful consumption of heat energy, improves steam productivity,
The purpose is to extend the life of the boiler equipment.

[0032]

[Means for Solving the Problems] To achieve the above object
In the first means, the fuel is fed to the combustion chamber 3 in the boiler body 1.
Three vernanods of approximately equal capacity that can inject oil
Fuel to burners 6, 37, 7 and burner nozzles 6, 37, 7
Electricity connected to the fuel oil pipes 18, 39, 19 for feeding oil
The magnetic valves 20, 38, 21 and steam generated in the boiler body 1
The pressure P of the air is different from the predetermined pressure P that is different in advance.₁，
P₃, P₂(P₁> P₃> P₂) Separately created in the following cases:
Move and actuate command V₁, V_Ten, V₂To be able to output
Also, the same amount of pressure as the burner nozzles 6, 37, 7
The switches 24, 40, 25 and the pressure P of the steam are P <
P₂Next, the operation command V is sent from the pressure switch 25.₂give
Opening all solenoid valves 20, 38, 21 when triggered
Order V_Five, V₁₁, V₆To the solenoid valves 20, 38, 21 and
The pressure P of the steam is P₃> P> P₂And the pressure switch
Operation command V from switch 40_TenSolenoid valve 2 when given
Open command V to open 0, 38_Five, V₁₁To solenoid valves 20, 38
An output command V is issued to the solenoid valve 21 while outputting.₆Is not output,
The pressure P of the steam is P₁> P> P₃Next to the pressure switch
Operation command V from Chi 24₁Solenoid valve 20 when given
Open command V to open_FiveOutput to the solenoid valve 20 and the solenoid valve
Open command V for 38 and 21₁₁, V₆Without outputting the steam
Pressure P is P> P₁And pressure switches 24, 40,
Operation command V from 25₁, V_Ten, V₂Is no longer given
Open command V to all solenoid valves 20, 38 and 21_Five, V
₁₁, V₆Equipped with a combustion control device 26 that does not output
In the second means, one burner nozzle is used.
7 or 6 of the capacity of the other burner nozzle 6 or 7
Injection of fuel oil into the combustion chamber 3 in the boiler body 1 is almost doubled
2 burner nozzles 6 and 7 that can be
Fuel oil pipes 18 and 19 for supplying fuel oil to the nozzles 6 and 7
Generated by the solenoid valves 20 and 21 connected to the boiler body 1
The pressure P of the generated steam is different from the predetermined pressure.
P₁, P₃, P₂(P₁> P₃> P₂) Separate in the following cases
And the operation command V₁, V_Ten, V₂So that you can output
Pressure switch 24, 40, 25 and the pressure of the steam
Force P is P <P₂From the pressure switch 25 to the operating finger
Order V₂Open the two solenoid valves 20 and 21 when
Open command V_Five, V₆To the solenoid valves 20 and 21, and
The air pressure P is P₃> P> P₂And the pressure switch 4
Operation command V from 0_TenSolenoid valves 20, 2 when given
The capacity of 1 is approximately twice that of other solenoid valves 20 or 21
Command V to open the solenoid valve 21 or 20₆Or V_FiveSolenoid valve
21 or 20, and to the solenoid valve 20 or 21
Open command V_FiveOr V₆Is not output and the pressure P of the steam is P₁
> P> P₃From the pressure switch 24 to the operation command V₁
Is given to solenoid valve 21 or 20
Open command V to open approximately 1/2 of solenoid valve 20 or 21_FiveOr V₆
Is output to the solenoid valve 20 or 21, and the solenoid valve 21 or
Open command V to 20₆Or V_FiveWithout outputting the pressure of the steam
P is P> P₁And pressure switch 24, 40, 25
Operation command V₁, V_Ten, V₂When is no longer given
Open command V to the two solenoid valves 20 and 21 _Five, V₆Does not output
The configuration including the combustion control device 26
By means, the fuel gas is injected into the combustion chamber 3 inside the boiler body 1.
Burner gun 27 and the burner gun 27
Electromagnetic connected to the fuel gas pipe 30 for delivering fuel gas to
Fuel gas is fed to the valve 33 and the burner gun 27.
Fuel gas arranged in parallel with the fuel gas pipe 30
Solenoid valve 41 with Olyphius 42 connected to pipe 29
And the fuel gas for feeding the fuel gas to the fuel gas pipes 29, 30.
At least one shutoff valve 34, 35 connected to the pipe 31
And the pressure P of the steam generated in the boiler body 1 is predetermined
Different predetermined pressure P₁, P₃, P₂(P₁> P₃>
P₂) Operate separately and operate command V in the following cases:₁，
V_Ten, V₂Pressure switch 24 adapted to output
40, 25, and the pressure P of the steam is P <P₂Next and before
Operation command V from pressure switch 25₂If given
Open the shutoff valves 34, 35 and solenoid valves 33, 41
Command V₈, V₉, V₇, V₁₂Shut off valves 34, 35 and electromagnetic
It is output to the valves 33 and 41, and the pressure P of the steam is P₃> P>
P₂And the operation command V is output from the pressure switch 40._TenTo
The shutoff valves 34 and 35 and the solenoid valve 41 when given
Open command V to open₈, V₉, V₁₂Shut off valves 34, 35 and
Output to the magnetic valve 41 and open command V to the solenoid valve 33.₇To
No output, the pressure P of the steam is P₁> P> P₃Next to the above
Operation command V from the pressure switch 24₁If given
Open command V for opening the shutoff valves 34, 35₈, V₉Shut-off valve 34,
35 to the solenoid valves 33 and 41
V₇, V₁₂Is not output and the pressure P of the steam is P> P₁Tona
From the pressure switches 24, 40 and 25₁，
V_Ten, V₂Shut-off valves 34, 3 if no longer given
5 and solenoid valves 33, 41 open command V₈, V₉, V₇, V₁₂
With a combustion control device 26 that does not output
In the fourth means, the combustion chamber 3 in the boiler body 1 is burned.
A burner gun 27 adapted to inject the raw gas and the burner gun 27.
Connects to the fuel gas pipe 30 that supplies the fuel gas to the nagan 27.
Fuel gas to the connected solenoid valve 33 and the burner gun 27.
Are arranged in parallel to the fuel gas pipe 30 to deliver
Connected without electricity to the fuel gas pipe 29
Fuel gas is fed to the magnetic valve 43 and the burner gun 27.
Are arranged in parallel with the fuel gas pipes 30 and 29.
An Olyphius 45 connected to the fuel gas pipe 44, and an electromagnetic
Fuel gas pipes 30, 29 to which valves 33, 43 are connected and
Fuel gas to the fuel gas pipe 44 connected to the refueling 45
Of at least one connected to the fuel gas pipe 31
Of the shutoff valves 34, 35 and the steam generated in the boiler body 1.
Predetermined pressures P that are different from each other in advance₁, P₃, P
₂(P₁> P₃> P₂) Operates separately and:
Operation command V₁, V_Ten, V₂Output pressure
And the pressure P of the steam is P <P
₂And the operation command V is output from the pressure switch 25.₂give
Shut off valves 34, 35 and solenoid valves 33, 4 when
Open command V to open 3₈, V₉, V₇, V₁₂Shut-off valves 34,3
5 and the solenoid valves 33 and 43 to output the steam pressure P.
P₃> P> P₂From the pressure switch 40
Order V_TenThe shutoff valves 34, 35 and the electric
Open command V to open the magnetic valve 43₈, V₉, V₁₂Shut-off valves 34,3
5 and the solenoid valve 43, and the solenoid valve 33 is opened.
Order V₇Is not output and the pressure P of the steam is P₁> P> P₃When
Operation command V from the pressure switch 24₁Given
Open command V to open the shutoff valves 34 and 35 when₈, V₉Shut off
Output to valves 34 and 35, and open to solenoid valves 33 and 43.
Command V₇, V₁₂Is not output and the pressure P of the steam is P> P₁
And the operation command V from the pressure switches 25, 40, 24
₂, V_Ten, V₁Shutoff valve 34 when
35 and solenoid valves 33 and 43 open command V₈, V₉, V₇, V
₁₂With a combustion control device 26 that does not output
I'm done.

[0033]

In the first means, when the pressure P of the generated steam becomes lower than the predetermined pressure P ₂ , the operation command V ₂ from the pressure switch 25 is given to the combustion control device 26, and the combustion control is performed. The opening commands V ₅ , V ₁₁ , V ₆ are given from the device 26 to all the solenoid valves 20, 38, 21 so that the solenoid valves 20,
38 and 21 open so that the fuel oil is burned by the burner nozzle 6,
It is injected and burned from 37, 7 (100% combustion).

When the vapor pressure P becomes higher than the predetermined pressure P ₂ but lower than the pressure P ₃ , the operation command V ₁₀ from the pressure switch 40 is given to the combustion control device 26 and the combustion control device 26 opens. The commands V ₅ and V ₁₁ are solenoid valves 20 and 38.
The solenoid valves 20 and 38 are opened, the opening command V ₆ is not given to the solenoid valve 21, and the solenoid valve 21 is closed. Therefore, the fuel oil is injected from the burner nozzles 6, 37 and burns (combustion of about 65%).

When the vapor pressure P becomes higher than the predetermined pressure P ₃ but lower than the pressure P ₁ , the operation command V ₁ from the pressure switch 24 is given to the combustion control device 26 and the combustion control device 26 opens. The command V ₅ is given to the solenoid valve 20 to open the solenoid valve 20, and the opening commands V ₆ and V ₁₁ are used to control the solenoid valves 38 and 2.
1, the solenoid valves 38 and 21 are closed. Therefore, the fuel oil is injected from the burner nozzle 6 and burned (combustion of about 30%).

When the vapor pressure P becomes higher than the predetermined pressure P ₁ , the operation commands V ₁ , V ₁₀ and V ₂ are not given from the pressure switches 24, 40 and 25 to the combustion control device 26, and the combustion control device 26 is burned. The opening commands V ₅ , V ₁₁ and V ₆ are not given from the control device 26 to the solenoid valves 20, 38 and 21. Therefore, the solenoid valves 20, 38, 21 are closed and fuel oil is not injected (0% combustion).

In the second means, when the vapor pressure P is lower than a predetermined pressure P ₂ , the solenoid valves 20 and 21 are opened and the fuel oil is injected from the burner nozzles 6 and 7 to burn (100 %combustion).

When the vapor pressure P is higher than the predetermined pressure P ₂ but lower than the pressure P ₃ , the solenoid valve 21 or 2 is used.
0 opens and the other solenoid valve 20 or 21 closes,
The fuel oil is injected from the burner nozzle 7 or 6 whose capacity is about twice that of the other burner nozzles 6 or 7 and burns (about 65%).
combustion).

When the vapor pressure P is higher than the predetermined pressure P ₃ but lower than the pressure P ₁ , the solenoid valve 20 or 2
Since 1 opens and the solenoid valve 21 or 20 closes, the fuel oil is injected from the burner nozzle 6 or 7 whose capacity is about 1/2 of the other burner nozzles 7 or 6 and burns (combustion of about 30%).

When the vapor pressure P is higher than the predetermined pressure P ₁ , the solenoid valves 20 and 21 are closed and fuel oil is not injected (0% combustion).

In the third means, when the vapor pressure P is lower than a predetermined pressure P ₂ which is set in advance, the shutoff valves 34 and 3 are provided.
5, the solenoid valve 33 and the solenoid valve 41 with the Olyphius 42 are opened, and the fuel gas is injected from the burner gun 27 and burned (100% combustion).

When the vapor pressure P is higher than the predetermined pressure P ₂ but lower than the pressure P ₃ , the shutoff valves 34, 3
5, the solenoid valve 41 is opened, the solenoid valve 33 is closed, the shutoff valve 3
4, 35, the solenoid valve 41, and the fuel gas that has passed through the Olyphius 42 are injected from the burner gun 27 and burned (approximately 6).
5% combustion).

When the vapor pressure P is higher than the predetermined pressure P ₃ but lower than the pressure P ₁ , the shutoff valves 34 and 35 are provided.
Open, the solenoid valves 33 and 41 close, and the shutoff valves 34 and 3
5, the fuel gas that passed the Oriihuis 42 is burner gun 2
It is injected from 7 and burns (approximately 30% burns).

When the vapor pressure P is higher than the predetermined pressure P ₁ , both the shutoff valves 34 and 35 and the electromagnetic valves 33 and 41 are closed, and the fuel gas is not injected (0% combustion). ).

In the fourth means, the solenoid valve 43 does not have an orifice, but the operation of each valve is the same as in the third means. In the case of 100% combustion, the shutoff valves 34, 35 and the solenoid valves are used. 33 and 43 are opened, the shutoff valves 34 and 35 and the solenoid valve 43 are opened in the case of approximately 65% combustion, the solenoid valve 33 is closed, and the shutoff valves 34 and 35 are opened in the case of approximately 30% combustion.
When the solenoid valves 33 and 41 are closed and the combustion is 0%, the shutoff valves 34 and 35 and the solenoid valves 33 and 43 are closed. in this case,
Unless the shutoff valves 34 and 35 are closed, the fuel gas is always delivered to the burner gun 27 through the orifice 45.

As described above, in each means of the present invention, 100
Since the combustion amount can be controlled at four positions of% combustion, approximately 65% combustion, approximately 30% combustion, and stop, frequent start and stop of the boiler do not occur.

[0047]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In each embodiment of the present invention, FIG.
The same parts as those shown in FIG. 6 are designated by the same reference numerals.

FIG. 1 is a first embodiment of the present invention corresponding to claim 1, and FIG. 2 is a second embodiment of the present invention corresponding to claim 2.
FIG. 3 shows a third embodiment of the present invention corresponding to claim 3, and FIG. 4 shows a fourth embodiment of the present invention corresponding to claim 4. In any of the embodiments, the combustion method is high combustion. (100
% Combustion), medium combustion (approximately 65% combustion), low combustion (approximately 30%)
So-called four-position control of combustion) and stop (0% combustion) is adopted.

The boiler combustion amount control system of the first embodiment shown in FIG. 1 uses oil such as heavy oil as fuel.

In FIG. 1, reference numeral 37 denotes a burner nozzle in which burner nozzles 6 and 7 are arranged side by side in a space surrounded by the upper header 5 of the boiler main body 1. The burner nozzle 37 has an electromagnetic valve 38 in the middle thereof. The front end of the connected fuel oil pipe 39 is connected, and the rear end of the fuel oil pipe 39 is connected to the fuel oil pipes 18, 19.
Together with the fuel oil pipe 22.

Reference numeral 16e denotes a water level detecting electrode rod inserted into the water level detecting container 14, and the water level detecting electrode rod 16e.
Is located between the lower end of the water level detecting electrode rod 16d and the lower end of the water level detecting electrode rod 16f, and the water level He detected by the water level detecting electrode rod 16e (Hd <He <H
f) can be given to the water level control device 17 as a signal.

Reference numeral 40 is a pressure switch connected to the steam pipe 12 together with the pressure switches 24 and 25.
When the pressure P of the steam flowing in the combustion chamber falls below a pressure P ₃ higher than a preset pressure P ₂ , an operation command V ₁₀ can be given from the pressure switch 40 to the combustion control device 26. The pressures P ₁ , P ₃ , P ₂ set in the pressure switches 25, 40, 24 have a relationship of P ₁ > P ₃ > P ₂ .

V ₁₁ is an opening command given from the combustion control device 26 to the solenoid valve 38, and the relationship between the pressure P and the pressures P ₃ and P ₂ is P.
_The solenoid valve 38 can be opened when ₃ >P> P ₂ .

In such a once-through boiler, for example, the steam pipe 12
When the pressure P of the steam flowing in the combustion chamber becomes lower than a preset pressure P ₂ , an operation command V ₂ is given from the pressure switch 25 to the combustion control device 26 (operation commands V ₁ and V ₁₀ from the pressure switches 24 and 40). Is not given), the solenoid valves 20, ₃ are opened by the opening commands V ₅ , V ₁₁ , V ₆ from the combustion control device 26.
8,21 open. Therefore, the fuel oil delivered from the fuel oil pump 23 is the fuel oil pipe 22, the fuel oil pipes 18, 3
9, 19 and solenoid valves 20, 3 provided in the middle thereof
The burner nozzles 6, 37, 7 are injected into the combustion chamber 3 through 8 and 21, and burned (100% combustion). In this case, the pressure relationship is P ₁ > P ₃ > P ₂ > P.

When the pressure P of the steam flowing through the steam pipe 12 becomes higher than the preset pressure P ₂ and lower than the pressure P ₃ ,
Operation command V ₁₀ from the pressure switch 40 to the combustion control device 26
Is given (actuation command V from the pressure switches 24, 25
₁ and V ₂ are not given), the solenoid valves 20 and 38 are opened by the opening commands V ₅ and V ₁₁ from the combustion control device 26, and the opening command V ₆ is not output, so the solenoid valve 21 is closed. Therefore, the fuel oil passes through the fuel oil pipe 22, the fuel oil pipes 18, 39 and the electromagnetic valves 20, 38 provided in the middle thereof, and is injected from the burner nozzles 6, 37 into the combustion chamber 3 to be burned (approximately 65). %combustion). In this case, the pressure relationship is P ₁
> P ₃ >P> P ₂ .

When the pressure P of the steam flowing through the steam pipe 12 becomes higher than the preset pressure P _{3 and} lower than the pressure P ₁ , an operation command V ₁ is given from the pressure switch 24 to the combustion control device 26. (The operation commands V ₁₀ and V ₂ from the pressure switches 40 and 25 are not given), and the combustion control device 26
The solenoid valve 20 is opened by the open command V ₅ from the above, and the solenoid valves 38 and 21 that do not output the open commands V ₁₁ and V ₆ are closed. Therefore, the fuel oil passes through the fuel oil pipe 22, the fuel oil pipe 18, and the solenoid valve 20 provided in the middle thereof, and is injected into the combustion chamber 3 from the burner nozzle 6 and burned (approximately 30%).
combustion). The pressure relationship in this case is P ₁ >P> P ₃
> P ₂ .

When the pressure P of the steam flowing through the steam pipe 12 is higher than the preset pressure P ₁ , the pressure switch 2
The operation commands V ₁ , V ₁₀ and V ₂ are not given to the combustion control device 26 from 4, 40 and 25, and the opening commands V ₅ , V ₁₁ and V ₆ are not output from the combustion control device 26. Therefore, the solenoid valves 20, 38, 21 are closed and the burner nozzles 6, 37, 7 are closed.
The fuel oil injection from is stopped (0% combustion). On this occasion,
The fuel oil pump 23 is stopped by the start / stop command V ₃ from the combustion control device 26, and the start / stop command from the water level control device 17 is started.
The water supply pump 9 is stopped by the stop command V ₄ .

On the other hand, 100% combustion, about 65% combustion, about 3
In the case of 0% combustion, water is heated in the boiler main body 1 to generate steam, but in this case, the feed water and the flow of steam are the same as those in the conventional once-through boiler, and therefore description thereof will be omitted.

In the four position control, the boiler body 1
The water level in the heating pipe 2 is simultaneously controlled.

For example, at the time of 100% combustion, the water level in the water level detection container 14 must be positioned between Hb and Hc. Therefore, at the time of 100% combustion, the water level is between Hc and Hd above the lower end of the water level detecting electrode rod 16c in the water level detecting container 14, and the signal from the water level detecting electrode rods 16a, 16b, 16c. Is the water level control device 1
7 is supplied to the water supply pump 9 by the start / stop command V ₄ given from the water level control device 17 to the water supply pump 9 even if the operation command V ₂ is given from the combustion control device 26 to the water level control device 17. 9 is stopped.

When the water level in the heating tube 2 of the boiler body 1 is extended by 100% combustion, the water level in the water level detecting container 14 is lowered, and the water level is lowered below Hb, and the water level detecting electrode rod 16a.
When the water is detected only by, the operation command V ₂ is given from the combustion control device 26 to the water level control device 17, so that the start / stop command V ₄ given from the water level control device 17 to the water supply pump 9 is used. The water supply pump 9 is started, and water is sent to the lower header 4 of the boiler body 1 by the water supply pump 9. When the water level rises and water is detected by the water level detecting electrode rods 16a, 16b, 16c,
The water supply pump 9 is stopped again by the start / stop command V ₄ .

At the time of 65% combustion, the water level detecting container 14
Since the inner water level must be positioned between Hc and Hd, the water level is above the lower end of the water level detecting electrode rod 16d and the water level detecting electrode rods 16a, 16b,
Water supply pump 9 when detected by 16c and 16d
Is stopped, the water level drops and the water level detection electrode rod 16
When water is detected by a and 16b, the water supply pump 9 is started, the water level rises, and the water level detecting electrode rod 1
When it comes to be detected by 6a, 16b, 16c, 16d, the water supply pump 9 stops again.

At the time of 30% combustion, the water level detecting container 14
Since the internal water level must be positioned between Hd and He, the water level detection electrode rods 16a, 16b,
When water is detected by 16c, 16d, 16e,
The water supply pump 9 is stopped, and when the water level drops and water is detected only by the water level detection electrode rods 16a, 16b, 16c, the water supply pump 9 is activated and the water level rises to detect the water level. Electrode rods 16a, 16b, 16c, 1
When it comes to be detected by 6d and 16e, the water supply pump 9 stops again.

Even when the combustion is about 65% and about 30%, the operation commands V ₁₀ and V ₁₀ are required to start the water supply pump 9.
₁ must be provided from the combustion control device 26 to the water level control device 17.

The relationship between the combustion state and the water level corresponding to the boiler load when the above water level control is performed is shown in FIG.
The heights of the white frames Y ₁ , Y ₂ , and Y ₃ at 100 are in the combustion state 100.
The control ranges of the water levels of%, 65% and 30% are shown.

Thus, the boiler load (combustion amount) can be reduced to about 30% by performing the so-called four-position control by setting the control water level in three stages.

As described above, according to the boiler combustion amount control device of the present embodiment, so-called four-position control is performed, and the combustion amount can be reduced to about 30%. Therefore, the boiler is repeatedly operated and stopped. The number of times the post-purge and the pre-purge are also decreased. Therefore, in the boiler combustion amount control device of this embodiment, the boiler body 1
And the post-purge accumulated in the system passage of combustion gas,
Since the amount of thermal energy that accompanies the air during the prepurge and is released to the atmosphere is reduced, energy can be saved.

Further, when the steam consumption amount suddenly increases due to a decrease in the number of repetitions of boiler stoppage, post-purge, and pre-purge, and the steam pressure sharply decreases, it becomes possible to immediately increase the combustion amount, and the steam pressure can be increased. Fluctuations are reduced and productivity is improved.

Further, since the number of times the boiler body 1 and other equipment are heated or not heated is reduced, the number of times thermal stress is repeated in the boiler body 1 and other equipment and the number of times auxiliary equipment is started and stopped is reduced. However, it is possible to extend the life of the boiler.

The boiler combustion amount control system of the second embodiment shown in FIG. 2 uses oil such as heavy oil as the fuel as in the first embodiment. However, unlike the first embodiment, in the second embodiment, the burner nozzle 37 and the solenoid valve 38 of FIG.
7, the solenoid valves 20, 21, and the fuel oil pipes 18, 19 only are provided, and the burner nozzle 6 system has a capacity of 1/3 of the fuel oil flow rate at 100% combustion and the burner nozzle 7 system has 100 2/3 of fuel oil flow rate during combustion
By setting the flow rate of the burner nozzle 7 as a capacity, the system of the burner nozzle 7 has a capacity twice that of the system of the burner nozzle 6.

In this case, the fuel oil is injected from the burner nozzles 6 and 7 at 100% combustion, the fuel oil is injected from the burner nozzle 7 at about 65% combustion, and the fuel oil is injected from the burner nozzle 6 at about 30% combustion. Let

The capacity of the burner nozzle 6 may be approximately double that of the burner nozzle 7.

The once-through boiler of the third embodiment shown in FIG. 3 uses gas as fuel.

In FIG. 3, reference numeral 41 is a solenoid valve provided with an oil filter 42, which is provided in the middle of the fuel gas pipe 29.

V ₁₂ is an opening command given to the solenoid valve 41 from the combustion control device 26 when the operation commands V ₁₀ and V ₂ from the pressure switches 40 and 25 are given to the combustion control device 26.

In such a once-through boiler, for example, the steam pipe 12
When the pressure P of the steam flowing in the combustion chamber becomes lower than P ₂ which is set in advance, an operation command V ₂ is given from the pressure switch 25 to the combustion control device 26, and the opening commands V ₈ , V ₉ , V from the combustion control device 26 are given. ₇ , V ₁₂ opens the shutoff valves 34, 35, the solenoid valve 33, and the solenoid valve 41 with the Olyphius 42. Therefore, the fuel gas fed from the upstream side of the fuel gas pipe 31 is supplied to the fuel gas pipe 31 and the valves 34, 35, 36 provided in the middle portion thereof, the fuel gas pipe 29 and the middle portion thereof. It is injected from the burner gun 27 into the combustion chamber 3 through the provided solenoid valve 41 and the solenoid valve 41 attached to the solenoid valve 41, the fuel gas pipe 30 and the solenoid valve 33 and fuel gas pipe 28 provided in the middle thereof. Burns (100% burning).

When the pressure P of the steam flowing through the steam pipe 12 becomes higher than the preset pressure P _{2 and} lower than the pressure P ₃ , an operation command V ₁₀ is given from the pressure switch 40 to the combustion control device 26. Then, the combustion control device 26 issues an open command V ₇
Is not output, the solenoid valve 33 is closed. Therefore, the fuel gas is the fuel gas pipe 31 and each valve 34, 35, 36 provided in the middle portion thereof, the fuel gas pipe 29 and the solenoid valve 41 provided in the middle portion thereof, and the oil valve attached to the solenoid valve 41. 42, the fuel gas pipe 28, and is injected into the combustion chamber 3 from the burner gun 27 and burned (about 65%).
combustion).

When the pressure P flowing in the steam pipe 12 becomes higher than the preset pressure P ₃ and lower than the pressure P ₁ ,
Operation command V ₁ from the pressure switch 24 to the combustion control device 26
Is given and the opening commands V ₇ and V ₁₂ are no longer output from the combustion control device 26, the solenoid valves 33 and 41 are closed. Therefore, the fuel gas is the fuel gas pipe 31 and the valves 34, 35, 36 provided in the middle portion thereof, the fuel gas pipe 29 and the solenoid valve 41 provided in the middle portion thereof.
2. It passes through the fuel gas pipe 28 and is injected into the combustion chamber 3 from the burner gun 27 and burned (combustion of about 30%).

When the pressure P of the steam flowing through the steam pipe 12 is higher than the preset pressure P ₁ , the pressure switch 2
The operation commands V ₁ , V ₁₀ and V ₂ are not given to the combustion control device 26 from 4, 40 and 25, and the open commands V ₈ , V ₉ , V ₇ and V ₁₂ are outputted from the combustion control device 26. Since they disappear, the shutoff valves 34 and 35 and the solenoid valves 33 and 41 are closed. Therefore, the injection of fuel gas from the burner gun 27 is stopped (0% combustion).

The control of the water supply pump 9 and the water level at the time of such four-position control is the same as that of the boiler combustion amount control device of FIG.

The boiler combustion amount control system of the fourth embodiment shown in FIG. 4 uses gas as fuel, as in the third embodiment. However, unlike the third embodiment, in the fourth embodiment, the solenoid valve 4 with the Oriifu 42 shown in FIG. 3 is not provided, and the solenoid valve 4 without the Oriihuis in the fuel gas pipe 29 is provided.
3, the fuel gas pipes 44 connected in parallel to the fuel gas pipes 29, 30 are provided with an orientation filter 45.

With such a configuration, as in the embodiment of FIG. 3, 100% combustion, approximately 65% combustion, approximately 30% combustion, 0%
Burning is possible.

Also in the case of the four-position control shown in FIGS. 2, 3, and 4,
As in the case of the embodiment of FIG. 1, it is possible to save energy, improve steam productivity by preventing steam pressure fluctuations, and prolong the boiler life.

In the embodiment of the present invention, the case where the four-position control is applied to the once-through boiler has been described, but it can be applied to a boiler other than the once-through boiler, and other points of the present invention. It goes without saying that various changes can be made without departing from the above.

[0085]

According to the boiler combustion amount control apparatus of the present invention, in any of the first to fourth aspects, the thermal energy discharged to the outside by the pre-purge and the post-purge is reduced, so that energy saving can be achieved. Even if the steam consumption increases when the boiler is stopped, post-purged or pre-purged, the steam pressure does not drop extremely, and the time until the steam with a predetermined pressure can be obtained can be shortened. Therefore, the productivity of steam is improved, and further, the number of repetitions of thermal stress and the number of times of starting and stopping auxiliary machinery are reduced, so that the life of the once-through boiler can be extended, and various other excellent effects can be obtained.

[Brief description of drawings]

FIG. 1 is a control block diagram of a first embodiment of a boiler combustion amount control device of the present invention.

FIG. 2 is a control block diagram of a second embodiment of the boiler combustion amount control device of the present invention.

FIG. 3 is a control block diagram of a third embodiment of the boiler combustion amount control device of the present invention.

FIG. 4 is a control block diagram of a fourth embodiment of the boiler combustion amount control device of the present invention.

FIG. 5 is a control block diagram of an example of a conventional boiler combustion amount control device.

FIG. 6 is a control block diagram of an example of a conventional boiler combustion amount control device.

FIG. 7 is a graph showing a relationship between a combustion state and a water level in the boiler combustion amount control device of the present invention and the conventional boiler.

[Explanation of symbols]

1 Boiler body 6,7 Burner nozzle 18,19 Fuel oil pipe 20,21 Solenoid valve 24,25 Pressure switch 26 Combustion control device 27 Burner gun 29,30,31 Fuel gas pipe 33 Solenoid valve 34,35 Shutoff valve 37 Burner nozzle 38 Solenoid valve 39 Fuel oil pipe 40 Pressure switch 41 Solenoid valve 42 Oriihus 43 Solenoid valve 44 Fuel gas pipe 45 Oriihuis P, P ₁ , P ₂ , P ₃ Pressure V ₁ , V ₂ Operation command V ₅ , V ₆ Open command V ₇ , V ₈ , V ₉ open command V ₁₀ operation command V _11, V ₁₂ open command

Claims (4)

[Claims] 1. Three burner nozzles 6, each having a substantially equal volume, capable of injecting fuel oil into a combustion chamber 3 in a boiler body 1.
Solenoid valve 2 connected to 37, 7 and fuel oil pipes 18, 39, 19 for supplying fuel oil to each burner nozzle 6, 37, 7.
0, 38, 21 and predetermined pressures P ₁ , P ₃ , P ₂ in which the pressure P of the steam generated in the boiler body 1 is different from each other.
In the case of (P ₁ > P ₃ > P ₂ ) or less, the pressure equal to that of the burner nozzles 6, 37, 7 is set so as to operate separately and output the operation commands V ₁ , V ₁₀ and V _2. The switches 24, 40, 25 and the opening command V ₅ , which opens all the solenoid valves 20, 38, 21 when the pressure P of the steam becomes P <P ₂ and the operation command V ₂ is given from the pressure switch 25. When V ₁₁ and V ₆ are output to the solenoid valves 20, 38 and 21, the pressure P of the steam becomes P ₃ >P> P ₂ , and the operation command V ₁₀ is given from the pressure switch 40, the solenoid valve 2
Open commands V ₅ and V ₁₁ for opening 0 and 38 are output to the solenoid valves 20 and 38, and open command V ₆ is not output to the solenoid valve 21,
When the pressure P of the steam becomes P ₁ >P> P ₃ and the operation command V ₁ is given from the pressure switch 24, the solenoid valve 20
The opening command V ₅ for opening the valve is output to the solenoid valve 20 and the opening commands V ₁₁ and V ₆ are not output to the solenoid valves 38 and 21, the pressure P of the steam becomes P> P ₁ , and the pressure switches 24 and 40 ，
When the operation commands V ₁ , V ₁₀ and V ₂ are no longer given from 25, the opening commands V ₅ and V are sent to all the solenoid valves 20, 38 and 21.
A boiler combustion amount control device comprising a combustion control device 26 that does not output ₁₁ , V ₆ . 2. The capacity of one burner nozzle 7 or 6 is
The capacity of the other burner nozzle 6 or 7 is approximately double and the boiler
Fuel oil can be injected into the combustion chamber 3 in the main body 1 2
Burn the individual burner nozzles 6, 7 and each burner nozzle 6, 7.
Solenoid valve connected to fuel oil pipes 18 and 19 for feeding fuel oil
20, 21 and the pressure P of the steam generated in the boiler body 1
Is a predetermined pressure P that is different from each other in advance.₁, P₃, P₂(P₁
> P₃> P₂) Operate separately and activate fingers individually in the following cases:
Order V₁, V_Ten, V₂Pressure switch that can output
24, 40, 25 and the pressure P of the steam is P <P₂Tona
Operation command V from the pressure switch 25₂Was given
Open command V to open the two solenoid valves 20 and 21 in case_Five, V₆To
Output to the solenoid valves 20 and 21, and the pressure P of the steam is P₃>
P> P₂And the operation command V is output from the pressure switch 40.
_TenIs given, the capacity of the solenoid valves 20, 21 is
Of the solenoid valve 20 or 21
Open command V to open 20₆Or V_FiveTo the solenoid valve 21 or 20
The solenoid valve 20 or 21 is opened with an opening command V_FiveOr V₆
Is not output and the pressure P of the steam is P ₁> P> P₃Before next
Operation command V from the pressure switch 24₁If given
A solenoid valve whose capacity is approximately 1/2 of that of the solenoid valve 21 or 20
Open command V to open 20 or 21 _FiveOr V₆Solenoid valve 20 or
21 and an opening command V is sent to the solenoid valve 21 or 20.
₆Or V_FiveIs not output and the pressure P of the steam is P> P₁Tona
From the pressure switches 24, 40 and 25₁，
V_Ten, V₂2 solenoid valves 2 when no longer given
Open command V to 0, 21_Five, V₆Combustion that did not output
Boiler combustion characterized by comprising a control device 26
Quantity control device. 3. A burner gun 27 adapted to inject a fuel gas into a combustion chamber 3 in a boiler body 1, an electromagnetic valve 33 connected to a fuel gas pipe 30 for feeding the fuel gas to the burner gun 27, A solenoid valve 41 with an Olyphius 42 connected to a fuel gas pipe 29 arranged in parallel with the fuel gas pipe 30 so as to supply the fuel gas to the burner gun 27, and the fuel gas to the fuel gas pipes 29, 30. At least one shutoff valve 34 connected to the fuel gas pipe 31 for delivery,
35 and the predetermined pressures P ₁ , P ₃ , P ₂ (P ₁ > P ₃ ) at which the pressure P of the steam generated in the boiler body 1 is different from each other.
> P ₂ ) The pressure switch 2 which operates independently and can output the operation commands V ₁ , V ₁₀ and V ₂ in the following cases:
4, 40, 25, and the opening command for opening the shutoff valves 34, 35 and the solenoid valves 33, 41 when the pressure P of the steam is P <P ₂ and the operation command V ₂ is given from the pressure switch 25. V ₈ , V ₉ , V ₇ , and V ₁₂ are output to the shutoff valves 34 and 35 and the solenoid valves 33 and 41, and the pressure P of the steam is P ₃
>P> P ₂ , and when the operation command V ₁₀ is given from the pressure switch 40, the opening commands V ₈ , V ₉ and V ₁₂ for opening the shutoff valves 34 and 35 and the solenoid valve 41 are cutoff valves 34 and 35.
And the solenoid valve 41 and the opening command V ₇ is not output to the solenoid valve 33, the pressure P of the steam becomes P ₁ >P> P ₃ , and the operation command V ₁ is given from the pressure switch 24. The opening commands V ₈ and V ₉ for opening the shutoff valves 34 and 35 are output to the shutoff valves 34 and 35, and the opening commands V ₇ and V ₁₂ are not output to the solenoid valves 33 and 41. When P> P ₁ and the operation commands V ₁ , V ₁₀ , and V ₂ are no longer given from the pressure switches 24, 40, and 25, the shutoff valve 3
4, 35 and solenoid valves 33, 41 open commands V ₈ , V ₉ ,
A boiler combustion amount control device comprising a combustion control device 26 which does not output V ₇ and V ₁₂ . 4. A burner gun 27 capable of injecting fuel gas into the combustion chamber 3 in the boiler body 1, and a solenoid valve 33 connected to a fuel gas pipe 30 for feeding fuel gas to the burner gun 27, Solenoid valve 43 without an orifice connected to a fuel gas pipe 29 arranged in parallel with the fuel gas pipe 30 so as to feed the fuel gas to the burner gun 27.
An Oriihuis 45 connected to a fuel gas pipe 44 arranged in parallel with the fuel gas pipes 30 and 29 to feed the fuel gas to the burner gun 27, and an electromagnetic valve 33,
At least one shut-off valve 3 connected to the fuel gas pipe 31 for feeding the fuel gas to the connected fuel gas pipes 30 and 29 of 43 and the connected fuel gas pipe 44 of the Olyphus 45.
4, 35 and the pressure P of the steam generated in the boiler body 1 are different from each other by predetermined pressures P ₁ , P ₃ , P ₂ (P ₁ >).
P ₃ > P ₂ ) A pressure switch 2 which operates independently and can output operation commands V ₁ , V ₁₀ and V ₂ in the following cases:
4, 40, 25, and an opening command for opening the shutoff valves 34, 35 and solenoid valves 33, 43 when the pressure P of the steam becomes P <P ₂ and an operation command V ₂ is given from the pressure switch 25. _{V 8, V 9, V 7} , and outputs V ₁₂ to shut-off valves 34, 35 and solenoid valves 33 and 43, the pressure P of the steam is P ₃
>P> P ₂ , and when the operation command V ₁₀ is given from the pressure switch 40, the opening commands V ₈ , V ₉ , V ₁₂ for opening the shutoff valves 34, 35 and the solenoid valve 43 are shutoff valves 34, 35.
And the solenoid valve 43 is output and the opening command V ₇ is not output to the solenoid valve 33, and the steam pressure P becomes P ₁ >P> P ₃ and the operation command V ₁ is given from the pressure switch 24. without outputting an open command V _7, V ₁₂ is the electromagnetic valve 33, 43 with the opening command V _8, V ₉ to open the shut-off valve 34, 35 to output to the shut-off valve 34 and 35, the pressure P of the steam is When P> P ₁ and the pressure switches 25, 40, 24 do not give operation commands V ₂ , V ₁₀ , V ₁ , shutoff valve 3
4, 35 and solenoid valves 33, 43 open commands V ₈ , V ₉ ,
A boiler combustion amount control device comprising a combustion control device 26 which does not output V ₇ and V ₁₂ .