JP3189728B2 - Combustion equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Field of the Invention The present invention relates to a combustion device for stepwise switching example control the combustion rate.

[0002]

BACKGROUND OF THE INVENTION Combustion devices, there is for switching and e control to that high and low two stages of combustion amount or more stages. In such a combustion apparatus, using one ejection amount of fuel is variable fuel nozzle, but there is to adjust the combustion rate,
In such a fuel nozzle, it is impossible to increase the ratio of the adjustment of the fuel ejection amount, also not performed well spray of fuel smaller the ejection amount, there is a case where the combustion quality deteriorates. Therefore, in the conventional combustion apparatus, generally, a plurality of fuel nozzles set the ejection amount to a predetermined value, upon switching example of the combustion amount is jetted from a fuel nozzle of required number by regulating the amount of fuel Is in place.

Meanwhile, the combustion device, which is performed the ejection of the fuel at the same time from a plurality of fuel nozzles, spray fuel interfere with each other, atomization and vaporization is insufficient, lowering the combustion performance There is. In this case, it is conceivable that a plurality of fuel nozzles are made to correspond to the respective combustion amounts, and one of them is selected and operated according to the combustion amount. actuates number of fuel nozzles at the same time, it is necessary to ignite from one fuel nozzle to the other fuel <br/> nozzle, since the fuel is excessively supplied, the amount of C O is increased when this Or black smoke is generated .

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide at least two fuel nozzles and selectively operate these fuel nozzles to achieve a two-fuel nozzle.
In a combustion device for switching over the different combustion amount, fuel
Increase in the amount of CO generated and the generation of black smoke when switching the amount of burning
It is to suppress life .

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 has at least two fuel nozzles, and these fuel nozzles are selectively provided. by operating in, the combustion device for switching on two or more different combustion amount, the amount of combustion off
In conversion example, the fuel nozzles and a certain period to be activated after the fuel nozzle and the switching <br/> example in operation prior to switching example, it actuates simultaneously, within this period of time, from at least one of the fuel nozzles By lowering the amount of fuel jet ,
When increasing the amount of combustion, the total amount of injected fuel is switched
Control so that the amount of fuel injected afterwards reduces the amount of combustion
If the fuel is injected, the total amount of fuel
It is characterized in that it is controlled to be a quantity .

[0006]

Next, an embodiment of the present invention will be described.
explain about. The present invention is realized in a combustion device including at least two fuel nozzles and selectively operating these fuel nozzles to switch between two or more different combustion amounts. Such a combustion device is used, for example, in a boiler or an incinerator.

[0007] combustion apparatus of the present invention, even without least comprises two fuel nozzles, by operating one of these fuel nozzles selectively switches the combustion amount.
Further, the combustion device is capable of adjusting a fuel ejection amount.
At least one nozzle is provided. And the combustion
Device, when switching example of the combustion amount, the fuel nozzle and a period of time to be activated after the fuel nozzle and the switching example in operation prior to switching example, by operating at the same time, the flame in the fuel nozzle during operation prior to switching e performing ignition fuel nozzle to be activated after switching example by. During this changeover example, within this period of time, if reduce the ejection amount of the fuel from at least one of the fuel nozzle to increase the combustion amount is
The total fuel injection amount will be the fuel injection amount after switching.
Control to reduce the amount of combustion.
Control is performed so that the total is equal to the fuel injection amount before switching .

[0008] In the time of this switching example, air is an amount corresponding to the combustion amount after switching e is supplied, when it actuates the two fuel nozzle, the fuel becomes excessive,
The amount of generated CO increases or black smoke is generated. But,
As in the combustion device, the combustion amount of at least one of the fuel nozzles is reduced, and the total amount of fuel injection is changed after the switching.
By controlling the amount of fuel to be ejected, it is possible to suppress an increase in the amount of generated CO and the generation of black smoke without increasing the amount of ejected fuel to the air.

[0009] In the combustion apparatus, when the example switching of the combustion amount, but lowering the ejection amount of the fuel from one fuel nozzle, the amount of this reduction, the proportion of the combustion amount before and after the switching e Since the larger the value, the smaller the amount, the less the problem of deterioration of the flammability when adjusting the amount of injected fuel at the fuel nozzle is solved. Thus, according to the combustion device, the combustion device for switching two or more different combustion amount, the
In a state that the flammability was kept stable during the changeover example, it is possible to increase the ratio of the switching example before and after the combustion amount.

Further, in the combustion apparatus, the fuel nozzle is connected to a supply line and a return line of the fuel, by controlling by the return flow control means the flow rate of the line, the configuration ejection amount of the fuel is adjusted belongs to. The flow rate adjusting means, but simply can be constructed with a closing valve for opening and closing only, when applying the configuration of continuously changing the flow rate, such as a motor valve, a ratio of the switching example before and after the combustion quantity it is possible to adjust the amount of decrease in ejection amount of the fuel according to. In addition to this, a parallel flow paths midway multiple of the return line, the opening and closing valve such as an electromagnetic valve provided in each of the parallel flow paths, by selectively opening and closing these off valve, The flow rate may be adjusted stepwise.

Furthermore, among the plurality of fuel nozzles before Symbol combustion apparatus, at least one, ejection amount of the fuel can also be of a fixed. Thus, by jetting amount of the fuel to the fuel nozzles of the fixed structure of the combustion apparatus can be prevented from complication. Fuel nozzle to secure the ejection amount of fuel is preferably a fuel nozzle corresponding to the smallest combustion amount.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Will be described. Figure 1 is an explanatory view of an embodiment of the present invention
There, FIG. 2 is an explanatory diagram showing the relationship between the ejection amount of air volume and the fuel in the embodiment shown in FIG. Here, the real <br/>施例is obtained by applying the invention to a combustion device of the boiler. This combustion device is a three-position control type combustion device that is controlled in three stages of stop, low combustion, and high combustion.

In FIG. 1, a combustion device 1 is mounted on an upper part of a boiler 2. This combustion device 1 includes a first fuel nozzle 3 and a second fuel nozzle 4. The first fuel nozzle 3 corresponds to low combustion, and the second fuel nozzle 4 corresponds to high combustion. Further, the first fuel nozzle 3 has a fixed fuel ejection amount, and the second fuel nozzle 4 has a variable fuel ejection amount.

[0014] The first fuel nozzle 3 and the second fuel nozzle 4 is connected by branching the supply line 5 of the fuel. In this supply line 5, wherein the first fuel portion to branch toward the nozzle 3, is provided with a first fuel valve 6, the portion to branch toward the second fuel nozzle 4, the second fuel valve 7 is provided .

The fuel in the fuel tank 8 is supplied to the supply line 5 by a fuel pump 9. Then, by selectively operating the first fuel valve 6 and the second fuel valve 7 supplies fuel the the first fuel nozzle 3 and the second fuel nozzle 4.

[0016] The second fuel nozzle 4 is connected to the return line 10 of the fuel in communication with the fuel tank 8.
The return line 10, are a flow control valve 11 is provided as a flow control means for adjusting the flow rate of the fuel. That is, the second fuel nozzles 4, by withdrawing a portion of the fuel from the supply line 5 from the return line 10 has a configuration for adjusting the ejection amount of the fuel, the time of this adjustment, the The flow control valve 11 is operated. In this embodiment, the flow control valve 11 uses a motor valve .
There, it is continuously adjustable and the flow rate. Further, in the return line 10, between the flow control valve 11 and the fuel <br/> charge tank 8, an orifice device 1 for flow rate adjustment
2 is provided.

Further, the combustion device 1, is provided with a wind box 13 constituting the supply path of the combustion air, is connected to the blower 14 on the upstream side of the wind box 13. Wherein between the wind box 13 and the blower 14, it is provided with a damper mechanism 15 for adjusting the air volume from the blower 14 (the flow rate of the fuel air).

[0018] The first fuel valve 6, the second fuel valve 7, before
Serial flow control valve 11 and the damper mechanism 15, the ball <br/> is controlled by the controller 16 in response to the request of the combustion amount in Ira 2, whereby the combustion amount is stepwise control of the combustion device 1 Is done.

Now, the combustion apparatus 1 having the above-described configuration will be described.
In the small load of the boiler 2, when the burning of low combustion state, the first fuel valve 6 is opened, the second fuel valve 7 is in the closed state, the first Fuel is ejected only from the fuel nozzle 3. The damper mechanism 15 to adjust the air blowing amount from the blower 14 to the air blowing amount for low combustion.

[0020] An increase the load on the boiler 2 from the state of the low combustion, the controller 16 switches the combustion device 1 to a high combustion. The control at this time will be described with reference to FIG. Here, FIG. 2 shows, in order from the top,
Blowing rate of change, the ejection amount of change of the first fuel nozzle 3 of the fuel shows a variation of the ejection amount of the fuel in the change and the whole combustion apparatus 1 of the ejection amount of fuel in the second fuel nozzle 4 .

[0021] In the combustion of the combustion device 1 cut conversion <br/> obtain the high combustion, the control unit 16, the damper mechanism 15 is operated, the high the air volume supplied to the combustion device 1 It is the air volume for combustion. At about the same time to open the second fuel valve 7, the fuel is ejected from the second fuel nozzle 4 is ignited by flame produced by the first fuel nozzle 3. At this time, the flow control valve 11 is also controlled to increase the flow rate of the fuel in the return <br/> Ri line 10. In this state, the ejection amount of fuel from the second fuel nozzle 4 is smaller than the ejection amount for high combustion. For example,
The ejection amount of fuel at high burn is 100% and a 35% ejection amount of the fuel at low combustion, before during this changeover e
Ejection of the fuel from the serial second fuel nozzle 4 is set to 65%. That is, in the real施例this, in case the changeover example, the both when you are ejecting fuel from the first and second fuel nozzles 3,4, fuel total ejection amount of fuel at high burn Is set so as to correspond to the ejection amount.

[0022] In this state, feed air volume is an amount corresponding to the high combustion and said first and second fuel nozzles 3,4
Since the total amount of fuel ejected from the tank is for high combustion, the air ratio at this time does not fluctuate significantly, so that the amount of generated CO increases and black smoke is generated. Nothing.

[0023] After a certain period of time in this state, thereby closing the first fuel valve 6, the flow control valve 11
Actuating the closing direction. Then, ejection of fuel from the first fuel nozzle 3 is interrupted, the second fuel nozzles 4
Fuel gushes only from At this time, the flow control valve 1
1 is operating in the closing direction, the flow rate of fuel to the return line 10 is reduced, the amount of fuel injected from the second fuel nozzle 4 is increased, the ejection amount for high combustion.
In this high combustion state, the second fuel nozzles 4 line injection of fuel only by Utame, before and after the changeover example of the combustion amount, even larger proportion of the combustion fuel quantity, the fuel supply is good Done in Here, the predetermined period, the fuel ejected from the second fuel nozzle 4 by flame of the first fuel nozzle 3 is a period until the ignition, more preferably,
This is a period until the fuel from the second fuel nozzle 4 stably starts burning.

Next, in the combustion device 1, the ball <br/> load Ira 2 is reduced, when switching the combustion quantity to the low combustion is carried out with a substantially reverse order with the procedure. Nachi Suwa, the control device 16 and the said first fuel valve 6 second fuel valve 7 opened, the fuel is injected from both of the first fuel nozzle 3 and the second fuel nozzle 4.
At this time, we keep substantially created <br/> by moving simultaneously the flow control valve 11 in the opening direction. In this state, the flow rate of fuel in the return line 10 is increased, the amount of fuel injected from the second fuel nozzle 4 is reduced, the first fuel nozzle 3 and
The total ejection amount of the fuel from the second fuel nozzle 4 is made to the amount equivalent to the time of high combustion. Then, in this state, igniting the fuel from the first fuel nozzle 3 by flame in the second fuel nozzle 4. The controller 16 closes the second fuel valve 7 after a certain period of time in this state,
With interrupting the ejection of fuel from the second fuel nozzle 4, the air volume for low fire by operating the damper mechanism 15.

As described above , according to the combustion apparatus 1 ,
During example switching of the combustion amount, to reduce the ejection amount of the fuel from the second fuel nozzle 4 to 65% from 100%, is a rate of reduction of 35% is ejected amounts of such fuels in the case of using variable the fuel nozzle with one alone, 35% of the combustion amount of the low combustion state to the combustion of 100% of the high combustion, it is necessary to change 65%. Thus, before
According to the serial combustion device 1, ejection amount of the fuel can be used with less width adjustment variable of the fuel nozzle, moreover the amount of reduction is less the larger the ratio of the combustion amount in the high combustion and low combustion As a result, the problem of deterioration in combustibility of the fuel nozzle having a variable ejection amount is solved.

Further, in this embodiment, the adjustment of the combustion amount, carried out in high and low two stages of the high combustion state and a low combustion state
Unishi to have, but the present invention is the amount of combustion is not limited to the high and low two stages, can also be applied to those for adjusting the amount of combustion three or more stages. In this case, it is preferable that the fuel nozzle corresponding to the low combustion has a fixed fuel ejection amount.

Furthermore, Oite to this embodiment, the adjustment of the air amount, is performed by increasing or decreasing the channel cross-sectional area with the damper mechanism 15, to control the rotational speed of the blower 14 It can also be configured to adjust the feed flow rate depending on the.

[0028]

This by the invention lever according to the present invention, during the switching of the combustion amount, reduce the ejection amount of the fuel at least one fuel nozzle
By controlling the total fuel injection amount, the fuel injection amount to the air does not greatly increase, and C
O generation amount increases or the, Ru <br/> it is possible to suppress the occurrence of black smoke.

Furthermore, according to the inventions, when the switching <br/> example of the combustion amount, but lowering the ejection amount of the fuel from one fuel nozzle, the amount of this reduction, the front and rear of the switching e because fewer larger the ratio of the combustion amount, the combustion worsening problems in the case of adjusting the ejection amount of the fuel in the fuel nozzle is eliminated in the.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the relationship between the ejection amount of air volume and the fuel in the embodiment shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combustion device 3 First fuel nozzle (fuel nozzle) 4 Second fuel nozzle (fuel nozzle)

Claims (1)

(57) [Claims] 1. A comprising at least two fuel nozzles 3,4, by selectively operate these fuel nozzles 3,4, the combustion device 1 to switch on two or more different combustion amount, e switching of the combustion amount in the fuel nozzle and a period of time to be activated after the fuel nozzle and the switching example in operation prior to switching example, it actuates simultaneously, within this period of time, decrease the ejection amount of the fuel from at least one of the fuel nozzles To increase the amount of combustion
So that the total amount of fuel injected is equal to the amount of fuel injected after switching.
When controlling and reducing the amount of combustion, the total amount of fuel injected
A combustion apparatus for controlling the fuel injection amount before switching .