JP2019215098A - Combustion device - Google Patents

Abstract

To provide a combustion device capable of preventing a combustion property from deteriorating, while suppressing increase in the number of components and increase in the production cost.SOLUTION: A combustion device includes: a first nozzle for jetting a fuel at a low combustion stage; a second nozzle for jetting a fuel at a medium combustion stage and a high combustion stage; and a third nozzle for jetting a fuel at the high combustion stage. Regarding the second nozzle and the third nozzle, the jet amount is adjusted by one multi control valve, and in the case of shifting from the low combustion stage to the middle combustion stage, the fuel supply to the second nozzle is started by controlling the opening of the multi control valve while maintaining the fuel supply to the first nozzle (t2), and then, the fuel supply to the first nozzle is stopped before the opening becomes the opening in which the maximum amount of the fuel is supplied to the second nozzle (t3).SELECTED DRAWING: Figure 2

Description

  The present invention relates to a combustion device for injecting fuel into a combustion chamber and burning it.

  Conventionally, three nozzles having different fuel injection amounts are provided as nozzles for injecting fuel, and 100% combustion in which fuel is injected from all nozzles and burned according to vapor pressure, and fuel is injected from two nozzles. There is a boiler device that controls to either 65% combustion in which fuel is burned by combustion or 30% combustion in which fuel is injected from one nozzle and burns (for example, see Patent Document 1).

JP-A-6-147402

  However, in a conventional combustion device, fuel is injected from a plurality of nozzles in a combustion state such as 100% combustion and 65% combustion. In this case, since the fuel injected from each nozzle burns in an overlapping state, poor combustion occurs, and for example, there is a possibility that the generation amount of soot, Nox, or the like increases.

  In order to solve this point, in order to reduce the average number of nozzles for injecting fuel, for example, when shifting the combustion state, the nozzle corresponding to the combustion state of the transition destination is ignited, It is conceivable to stop the injection from the nozzle. However, in this case, it is necessary to inject fuel little by little from the nozzle corresponding to the combustion state of the transition destination in order to make the fire without misfiring. For this reason, a separate fuel supply line for injecting fuel little by little is provided separately from the fuel supply line that injects fuel from the nozzles, and an adjustment valve that adjusts the flow rate of fuel corresponding to each nozzle is provided. Must be provided. As a result, there is a possibility that the number of parts increases and the manufacturing cost increases.

  The present invention has been conceived in view of such circumstances, and provides a combustion device that can prevent a decrease in flammability while suppressing an increase in the number of parts and an increase in manufacturing cost.

  A combustion device according to an aspect of the present invention includes a first ejection unit that ejects fuel, a fuel control valve that controls fuel supplied to the first ejection unit, a second ejection unit that ejects fuel, and a third ejection unit. A multi-way adjustment valve that adjusts a flow rate of fuel supplied to the second ejection section and the third ejection section, and a control section that controls opening and closing of the fuel control valve and opening degree of the multi-way adjustment valve, The control section controls the fuel control valve to supply fuel to the first ejection section in the first combustion stage, and the second combustion section has a larger combustion amount than the first combustion stage from the first combustion stage. When shifting to the combustion stage, after controlling the opening of the multi-way regulating valve to start fuel supply to the second ejection part while maintaining fuel supply to the first ejection part, the second ejection part is started. Until the maximum amount of fuel is supplied to the opening, Control to stop the fuel supply to the first ejection part.

  According to the configuration described above, the flow rate of the fuel supplied to the second ejection portion and the third ejection portion can be adjusted by the multi-way adjustment valve, so that an increase in the number of components of the combustion device and an increase in manufacturing cost can be suppressed. Further, in the second combustion stage, the supply of fuel to the first ejection portion is stopped and the fuel ejected from the second ejection portion is burned, so that occurrence of poor combustion can be reduced.

  Preferably, in the third combustion stage in which the combustion amount is larger than the second combustion stage, the control unit controls the opening of the multi-way regulating valve to supply a maximum amount of fuel to the second ejection unit. While controlling the flow rate of the fuel supplied to the third jetting section.

  According to the above configuration, the amount of combustion in the second combustion stage and the third combustion stage can be adjusted by controlling the opening of the multi-way adjustment valve. Therefore, the processing by the control unit can be simplified and the processing load can be reduced.

  Preferably, when the control unit shifts from the first combustion stage to the second combustion stage, the opening of the multi-way regulating valve is smaller than the opening at which the maximum amount of fuel is supplied to the second ejection unit. After reaching a predetermined opening, the opening of the multi-way adjustment valve is controlled so that the opening of the multi-way adjustment valve is faster than the opening speed of the multi-way adjustment valve until the opening is reached. .

  According to the above configuration, it is possible to prevent a misfire when the fire is transferred from the first ejection part to the second ejection part, and after the fire is made, the combustion amount in the second combustion stage is obtained only by the second ejection part. As fast as you can.

  Preferably, when the control unit shifts from the second combustion stage to the first combustion stage, the control unit controls an opening degree of the multi-way adjustment valve to supply a maximum amount of fuel to the second ejection unit. The fuel control valve is controlled to supply fuel to the first jetting portion from the time when the fuel injection valve is closed.

  According to the above configuration, it is possible to prevent a misfire when the fire is transferred from the second ejection portion to the first ejection portion.

It is a figure which shows the structure of a combustion apparatus typically. 4 is a time chart illustrating an operation of the combustion device.

<About schematic structure>
Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, a schematic configuration of a combustion device 1 according to the present embodiment will be described with reference to FIG. The combustion device 1 is mounted on an oil-fired boiler, a gas-fired boiler, or the like.

  The combustion device 1 controls a first nozzle 4, a second nozzle 2, and a third nozzle 3 for ejecting fuel, a plurality of valves 41 to 45, and opening and closing (or opening degrees) of these valves 41 to 45. And a control unit 5. Note that the fuel may be a liquid such as oil or a gas such as a gas.

  The first nozzle 4, the second nozzle 2, and the third nozzle 3 constitute first to third ejection parts for ejecting fuel to the combustion chamber 9, respectively. In addition, although a nozzle is illustrated as an ejection part, the ejection part is not limited to the nozzle as long as it is a member capable of ejecting fuel, and may be constituted by another member.

  The first nozzle 4 ejects fuel at the start of combustion, and the ejected fuel is ignited by an ignition device (for example, an ignition transformer). Therefore, the first nozzle 4 also functions as an ignition nozzle. The second nozzle 2 ejects fuel and is ignited by the first nozzle 4. The third nozzle 3 ejects fuel and is ignited by the second nozzle 2.

  The combustion stage of the fuel in the combustion chamber 9 changes according to the amount of fuel ejected from each of the nozzles 2 to 4, that is, the amount of fuel ejected. Specifically, a first combustion stage in which the fuel ejected from the first nozzle 4 is burned, a second combustion stage in which the fuel ejected from the second nozzle 2 is burned, and each of the second nozzle 3 and the third nozzle 3 And a third combustion stage for burning fuel ejected from the fuel cell. Since the amount of combustion increases in the order of the first combustion stage, the second combustion stage, and the third combustion stage, in the following description, the first combustion stage is a low combustion stage, the second combustion stage is a medium combustion stage, and the third combustion stage. The stage is also called the high combustion stage.

  The diameters (inner diameters) of the first nozzle 4, the second nozzle 2, and the third nozzle 3 may be the same or different. In the latter case, the respective maximum ejection amounts (flow rates) may have a relationship of “first nozzle 4 <second nozzle 2 <third nozzle 3”.

  In the present embodiment, the supply of fuel from the fuel tank 8 to the first nozzle 4, the second nozzle 2, and the third nozzle 3 is performed via three paths 61, 62a, and 62b branched from the main path 6. Is More specifically, the main route 6 branches into first and second routes 61 and 62 at an intermediate position, and the second route 62 further branches into two routes 62a and 62b at an intermediate position. The first nozzle 4 is connected to the first path 61. The second nozzle 2 is connected to one of the second paths 62 a, and the third nozzle 3 is connected to the other of the second paths 62 b.

  The valve 41 is provided on the main path 6 and is, for example, a valve that can be switched between an open state and a closed state, that is, a switching valve. The valve 42 is a switching valve provided on the first path 61. The valve 43 is a multi-way adjusting valve (three-way valve) provided at a branch point of the second path 62. The valve 44 is a switching valve provided on one path 62 a of the second path 62. The valve 45 is a switching valve provided on the other path 62 b of the second path 62.

  The valve 43 as a multi-way adjustment valve is a throttle valve whose opening degree can be adjusted, and is constituted by, for example, a motor valve. The valves 41, 42, 44, and 45 as switching valves are configured by, for example, solenoid valves, but may be configured by a motor valve similarly to the valve 43. In the following description, in order to facilitate these distinctions, the valve 41 is a main solenoid valve, the valve 42 is a first solenoid valve, the valve 44 is a second solenoid valve, the valve 45 is a third solenoid valve, and the valve 43 is a It is called a multi-way regulating valve.

  The control unit 5 controls opening and closing of the solenoid valves 41, 42, 44, 45 and controls (adjusts) the opening of the multi-way adjustment valve 43. The control unit 5 can proportionally control the opening of the multi-way adjustment valve 43. The control unit 5 is realized by a computer including a memory, a timer, and an arithmetic processing unit inside.

<Operation>
With reference to FIG. 2, the operation of the combustion device 1 according to the present embodiment will be described. FIG. 2 shows a change in the ejection amount of each nozzle along a time axis. Before combustion, all valves 41 to 45 are in a closed state.

  When starting the combustion (t1), the control unit 5 opens the main solenoid valve 41, and then (or simultaneously) opens the first solenoid valve 42 to supply fuel to the first nozzle 4. Thereby, the fuel is ejected from the first nozzle 4 at the maximum ejection amount (100%). In this state, ignition is performed by a spark generated in advance from the ignition device. The control unit 5 causes the fuel to be ejected only from the first nozzle 4 in the low combustion stage. Assuming that the ejection amount of fuel from the second nozzle 2 and the third nozzle 3 is “100” in the high combustion stage, the ejection amount of fuel from the first nozzle 4 in the low combustion stage is “25”. Stipulated. Therefore, the amount of combustion in the low combustion stage is 25/100 of the amount of combustion in the high combustion stage.

  When shifting from the low combustion stage to the middle combustion stage, the control unit 5 starts fuel supply to the second nozzle 2 while maintaining fuel supply to the first nozzle 4 (t2). That is, the control unit 5 opens the second solenoid valve 44 while keeping the main solenoid valve 41 in the open state, and increases the opening of the multi-way adjustment valve 43 proportionally. As described above, when shifting the combustion state in the combustion chamber 9 from the low combustion stage to the middle combustion stage, the control unit 5 controls the opening of the multi-way adjustment valve 43 while maintaining the fuel supply to the first nozzle 4. Then, fuel supply to the second nozzle 2 is started. As a result, the fuel supply to the second nozzle 2 can be gradually increased, so that it is possible to prevent misfire when shifting from the low combustion stage to the middle combustion stage without increasing the number of components.

  When the opening of the multi-way adjustment valve 43 reaches a predetermined opening, the controller 5 closes the solenoid valve 42 and stops the fuel supply to the first nozzle 4. The predetermined opening is smaller than the opening at which the maximum amount of fuel is supplied to the second nozzle 2 (hereinafter, referred to as “maximum supply opening”). In the middle combustion stage, the control unit 5 causes the second nozzle 2 to eject the maximum amount of fuel by setting the opening of the multi-way adjustment valve 43 to the maximum supply opening. The amount of fuel injected from the second nozzle 2 in the middle combustion stage is determined to be “55”. The predetermined opening degree is, for example, the sum of the fuel injection amount from the second nozzle 2 and the fuel injection amount (25) from the first nozzle 4 is the maximum fuel amount from the second nozzle 2 in the middle combustion stage. The opening is determined to be the ejection amount (55). More specifically, the predetermined opening degree is such that the fuel injection amount from the second nozzle 2 is “30 (= 55−25)”, which is about 54.5% (= 30) of the maximum amount from the second nozzle 2. / 55). In this way, the fuel supply to the first nozzle 4 is stopped before the opening of the multi-way regulating valve 43 reaches the maximum supply opening, that is, before the combustion state reaches the middle combustion stage. Thus, it is possible to prevent the combustion amount from being too large in the process of shifting from the low combustion stage to the middle combustion stage as compared with the case of the middle combustion stage.

  When the control unit 5 shifts from the low combustion stage to the middle combustion stage, after the opening of the multi-way adjustment valve 43 reaches a predetermined opening, the control unit 5 waits until the opening reaches the opening. It is desirable to control the opening degree of the multi-way adjustment valve 43 so that the opening speed is higher than the opening speed. That is, it is desirable that the speed at which the multi-way adjustment valve 43 opens is higher from the predetermined opening to the maximum supply opening than the speed until the predetermined opening. Specifically, the time required from the start of the control to proportionally open the multi-way regulating valve 43 to the opening of a predetermined value until the fuel injection amount from the second nozzle 2 reaches 54.5% of the maximum is defined as T1. Assuming that the time required from the predetermined opening to the maximum supply opening is T2, it is sufficient that the relationship of 54.5 / T1 <(100−54.5) / T2 is satisfied. Thus, after the first nozzle 4 is fired from the first nozzle 4 to the second nozzle 2 while the misfire is prevented, and after the fuel supply to the first nozzle 4 is stopped, the amount of combustion in the middle combustion stage can be quickly controlled.

  When the maximum supply opening is reached with the opening adjustment (expansion) of the multi-way adjustment valve 43 (t3), the ejection amount of the second nozzle 2 becomes the maximum ejection amount. That is, the maximum amount of fuel is supplied to the second nozzle 2. At this time, the control unit 5 stops adjusting the opening of the multi-way adjustment valve 43. Thereby, the combustion state in the combustion chamber 9 becomes the middle combustion stage. When shifting from the middle combustion stage to the low combustion stage, the control unit 5 sets the first electromagnetic valve until the opening of the multi-way regulating valve 43 changes from the maximum supply opening to the closed state (0). The valve 42 is opened to supply fuel to the first nozzle 4. In this case, the opening degree of the multi-way adjustment valve 43 is controlled so as to make a movement opposite to the case of shifting from the low combustion stage to the middle combustion stage. That is, when shifting from the middle combustion stage to the low combustion stage, the control unit 5 controls the opening of the multi-way adjustment valve 43 from the maximum supply opening to the predetermined opening during T2, and then performs the first operation. The opening of the multi-way adjusting valve 43 is controlled such that the electromagnetic valve 42 is opened and the opening of the multi-way adjusting valve 43 is changed from a predetermined opening to a closed state over T1.

  When shifting from the middle combustion stage to the high combustion stage, the control unit 5 restarts the opening adjustment of the multi-way adjustment valve 43 and opens the third solenoid valve 45 (t4). At this time, the second solenoid valve 44 is kept open. That is, the control unit 5 controls the flow rate of the fuel supplied to the third nozzle 3 while supplying the maximum amount of fuel to the second nozzle 2 by controlling the opening of the multi-way adjustment valve 43. This makes it possible to proportionally increase the amount of fuel injected from the third nozzle 3 while keeping the amount of injection from the second nozzle 2 constant (maximum amount of injection).

  The adjustment of the opening of the multi-way adjustment valve 43 is performed until the ejection amount from the third nozzle 3 reaches the maximum ejection amount. When the opening degree of the multi-way adjustment valve 43 is fully opened (100), the ejection amount from the third nozzle 3 becomes the maximum ejection amount (t5). Thereby, the combustion state in the combustion chamber 9 becomes a high combustion stage.

  As described above, since the amount of ejection from the second nozzle 2 and the third nozzle 3 can be adjusted by one adjustment valve (multi-way adjustment valve) 43, a mode in which an adjustment valve is provided for each of the second nozzle 2 and the third nozzle 3. In comparison with the above, it is possible to suppress an increase in the number of parts and an increase in manufacturing cost, to simplify the processing by the control unit 5, and to reduce the processing load.

  Further, when shifting from the low combustion stage to the middle combustion stage, the fuel ejected from the second nozzle 2 can be gradually increased by the multi-way regulating valve 43, so that the first nozzle 4 is connected to the second nozzle 4 without misfiring. 2 can be fired. In the middle combustion stage, fuel is ejected only from the second nozzle 2. Also, fuel is ejected only from the first nozzle 4 even in the low combustion stage. For this reason, since the combustion range in which fuel is ejected from the plurality of nozzles and burned is small, occurrence of poor combustion can be reduced throughout. Furthermore, since the opening of the multi-way adjusting valve 43 is controlled so as to open more quickly after reaching the predetermined opening than before reaching the predetermined opening, After the fuel injection from one nozzle 4 is stopped, it is possible to rapidly control the amount of combustion in the middle combustion stage by only the second nozzle 2.

  Further, when shifting from the middle combustion stage to the low combustion stage, the control unit 5 controls the opening of the multi-way adjusting valve 43 from the maximum supply opening to a predetermined opening during T2, and then performs the first operation. The opening of the multi-way adjustment valve 43 is controlled such that the electromagnetic valve 42 is opened and the opening of the multi-way adjustment valve 43 is changed from a predetermined opening to the closed state over T1. Therefore, it is possible to cause the second nozzle 2 to fire to the first nozzle 4 without increasing the number of parts and without causing a misfire.

  The present invention is not limited to the above embodiment, and various modifications and applications are possible. Hereinafter, modified examples of the above embodiment applicable to the present invention will be described.

  The combustion device 1 in the above embodiment has been described with respect to an example in which the combustion device 1 is controlled to one of four positions including a stop, a low combustion stage, and a high combustion stage. The control may be performed at any one of three positions including (a state in which fuel is ejected from only the second nozzle). Further, in the combustion stage (medium combustion stage, high combustion stage) controlled by the multi-way adjustment valve 43, proportional control is performed by adjusting the opening degree of the multi-way adjustment valve 43 so that an arbitrary load factor is obtained. You may.

  In the combustion device 1 according to the above embodiment, when shifting from the low combustion stage to the middle combustion stage, the opening degree of the multi-way regulating valve 43 is determined by the amount of fuel injected from the second nozzle 2 and the amount of fuel injected from the first nozzle 4. The example has been described in which the supply of fuel to the first nozzle 4 is stopped when the sum of the ejection amount of the first nozzle 4 and the predetermined opening degree becomes the ejection amount of fuel from the second nozzle 2 in the middle combustion stage. However, when the supply of fuel to the first nozzle 4 is stopped, the opening degree of the multi-way adjustment valve 43 is determined by the sum of the amount of fuel ejected from the second nozzle 2 and the amount of fuel ejected from the first nozzle 4. The present invention is not limited to this as long as the opening is equal to or less than a predetermined opening which is the amount of fuel injected from the second nozzle 2 in the middle combustion stage. For example, the injection of fuel from the second nozzle 2 The opening degree may be a predetermined amount (for example, 25), or may be an opening degree that can be obtained when a predetermined period of time has elapsed since the start of the control for opening the multi-way adjusting valve 43 at a predetermined speed. . Similarly, in the case of shifting from the middle combustion stage to the low combustion stage, similarly, when the fuel supply to the first nozzle 4 is started, the opening degree of the multi-way adjustment valve 43 is determined by the fuel injection from the second nozzle 2 If the sum of the amount and the amount of fuel injected from the first nozzle 4 is equal to or less than a predetermined opening which is the amount of fuel injected from the second nozzle 2 in the middle combustion stage, the condition is satisfied. Good.

  In the above embodiment, the example in which the second and third solenoid valves 44 and 45 are provided on the downstream side of the multi-way regulating valve 43 has been described. However, the present invention is not limited to this, and the second and third solenoid valves 44 and 45 are provided. May be provided, and one electromagnetic valve may be provided in the flow path 62 on the upstream side of the multi-way adjustment valve 43.

  The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Combustion device 2 2nd nozzle 3 3rd nozzle 4 1st nozzle 5 Control part 6 Main path 8 Fuel tank 9 Combustion chamber 41 Main solenoid valve 42 First solenoid valve 43 Multiway adjusting valve 44 Second solenoid valve 45 Third solenoid valve 61 1st route 62 2nd route 62a route 62b route

Claims (4)

A first ejection section for ejecting fuel,
A fuel control valve for controlling fuel supplied to the first ejection section;
A second ejection portion and a third ejection portion for ejecting fuel,
A multi-way adjustment valve for adjusting a flow rate of fuel supplied to the second ejection section and the third ejection section;
A control unit for controlling the opening and closing of the fuel control valve and the opening of the multi-way adjustment valve,
The controller is
In the first combustion stage, controlling the fuel control valve to supply fuel to the first ejection section,
When shifting from the first combustion stage to the second combustion stage in which the amount of combustion is larger than the first combustion stage, the opening degree of the multi-way regulating valve is controlled while maintaining the fuel supply to the first ejection portion. After the fuel supply to the second ejection portion is started, the fuel injection valve is controlled by controlling the fuel control valve until the opening amount at which the maximum amount of fuel is supplied to the second ejection portion. A combustion device that stops the fuel supply to the section.   In the third combustion stage, in which the combustion amount is larger than the second combustion stage, the control unit controls the opening of the multi-way regulating valve to supply the second ejection unit with the maximum amount of fuel, The combustion device according to claim 1, wherein a flow rate of the fuel supplied to the third ejection portion is controlled.   The control unit is configured such that, when shifting from the first combustion stage to the second combustion stage, the opening of the multi-way regulating valve is a predetermined opening smaller than an opening at which a maximum amount of fuel is supplied to the second ejection unit. After reaching the opening degree, the opening degree of the multi-way adjustment valve is controlled so as to open at a speed higher than the opening speed of the multi-way adjustment valve until the opening degree is reached. The combustion device according to claim 1 or claim 2.   When shifting from the second combustion stage to the first combustion stage, the control unit controls an opening of the multi-way regulating valve to close from an opening at which a maximum amount of fuel is supplied to the second ejection unit. The combustion device according to any one of claims 1 to 3, wherein the fuel control valve is controlled to supply fuel to the first ejection portion until the state is reached.

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