JP2006138561A - Combustion apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combustion apparatus capable of realizing a stable low combustion process. <P>SOLUTION: The combustion apparatus is provided with an air blower for adjusting air volume by controlling rotational speed at a rotational speed for low combustion which is slower than at least a rotational speed for high combustion, a rotational speed for ignition or the rotational speed for high combustion and the rotational speed for ignition and a damper for controlling air volume from the air blower by being positioned at least at an air volume position for high combustion, an air volume position for low combustion of which opening is smaller than the air volume position for high combustion or an air volume position for ignition of which opening is smaller than the air volume position for low combustion. To conduct combustion; in an ignition process, a rotational speed of a fan is set at the rotational speed for ignition and the damper is set at the air volume position for ignition; in a low combustion process, the rotational speed of the fan is set at the rotational speed for low combustion and the damper is set at the air volume position for low combustion; in a high combustion process, the rotational speed of the fan is set at the rotational speed for high combustion and the damper is set at the air volume position for high combustion. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a combustion apparatus provided with a blower that adjusts the air volume by controlling the rotational speed of a fan.

  In a combustion apparatus such as a boiler that performs combustion control in a plurality of combustion states set such as three positions of high combustion, low combustion, and stop, the amount of air required for each combustion state varies. . Therefore, an amount of combustion air required in each combustion state is supplied by connecting an inverter to an electric motor including a fan constituting a blower and increasing or decreasing the fan rotation speed.

  However, in such a combustion apparatus, it takes a certain amount of time until the necessary air volume is reached after the blower starts changing the fan rotation speed, whereas the change in the fuel supply amount is instantaneously performed by switching the valve. Therefore, there is a problem in that the ratio between the fuel and the amount of air (hereinafter referred to as “air-fuel ratio”) collapses and combustion failure occurs.

  Therefore, a combustion apparatus disclosed in the following Patent Document 1 has been proposed. The combustion apparatus described in Patent Document 1 is provided with a damper in an air passage connecting the blower and the combustion apparatus, and the opening degree of the damper is set to three opening degrees, full opening, ignition opening, and full closing. As shown in FIG. 5, when the ignition process is performed with the fan rotation speed set to the purge rotation speed and the damper set to the ignition opening degree, and the transition to the low combustion process after the completion of the ignition process, first the fan rotation speed The transition to the low combustion rotational speed is started, and the damper is fully opened after a predetermined time has elapsed from the start of the rotational speed change, thereby suppressing the collapse of the air-fuel ratio.

In the invention described in Patent Document 1, the damper opening is always fully opened in the low combustion process, and the air volume is not controlled by the damper, and the air volume necessary for the low combustion process is obtained only by changing the fan rotation speed. is there.
JP-A-9-210349

  However, the combustion apparatus described in Patent Document 1 is supplied from the blower in order to reduce the fan rotation speed until the air volume necessary for the low combustion process is reached in a state where the damper is in the fully open position in the low combustion process. Since the discharge pressure of the combustion air is weak and it is strongly affected by the wind pressure generated by the flame, the air volume supplied from the blower is not stable and the air-fuel ratio tends to collapse, and the combustion becomes unstable There was a point.

  The problem to be solved by the present invention is to provide a combustion apparatus capable of performing stable combustion even in a low combustion process.

  The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 is characterized in that the rotational speed of the fan is set to at least a high combustion rotational speed, an ignition rotational speed, or the high combustion rotational speed. And a blower that adjusts the air volume by controlling the rotation speed to a low combustion rotation speed lower than the ignition rotation speed, and at least a high combustion air volume position and a low combustion air opening having a smaller opening than the high combustion air volume position. It is provided with a damper for controlling the air volume from the blower by being arranged at an air volume position or an ignition air volume position having an opening smaller than that of the low combustion air volume position. The rotation speed of the fan is the rotation speed for ignition, the damper is the airflow position for ignition, and in the low combustion process, the rotation speed of the fan is the rotation speed for low combustion, and the damper is the airflow for low combustion. And location, in the high combustion process, high combustion speed a rotational speed of the fan, is characterized in that a high combustion airflow position the damper.

  According to the first aspect of the present invention, the necessary air volume can be supplied in each combustion state, and the discharge pressure on the blower side can be almost unaffected by the wind pressure generated by the flame. Stable combustion can also be performed in the process. As a result, it is possible to perform stable combustion with a low air volume and a low fuel supply amount, compared with the case where the decrease in the air volume is adjusted only by the rotational speed of the fan, so that the combustion volume in the low combustion process is reduced. It is possible to increase the turndown ratio (the ratio of the high combustion amount to the low combustion amount).

  The invention according to claim 2 performs the ignition process in a state where the rotational speed of the fan is set to the rotational speed for ignition and the damper is set to the airflow position for ignition, in addition to the constituent elements according to claim 1, After completion of the ignition process, the blower starts to change the rotational speed of the fan to a low combustion rotational speed, and after a predetermined time has elapsed from the start of the change of the rotational speed of the fan, the damper is moved to the low combustion airflow position. It is characterized by opening up to.

  According to the second aspect of the present invention, it is possible to make the air volume appropriate in the low combustion process following the ignition process, and to make the discharge pressure on the blower side almost unaffected by the wind pressure generated by the flame, The transition from the ignition process to the low combustion process can be performed stably.

  The invention according to claim 3 is characterized in that, in addition to the constituent elements of claim 1 or claim 2, the fuel supply amount in the ignition process and the subsequent low combustion process is made the same.

  According to the third aspect of the present invention, the amount of combustion can be reduced even in the ignition step, and the ignition shock can be further suppressed.

  According to the present invention, the necessary air volume can be supplied in each combustion state, and the discharge pressure on the blower side can be hardly affected by the wind pressure generated by the flame, and is stable even in the low combustion process. Combustion can be realized. Furthermore, the amount of combustion in the low combustion process can be reduced, and the turndown ratio can be increased.

  Next, an embodiment of the present invention will be described. The present invention is used in a combustion apparatus that performs multi-position combustion control such as three-position combustion control that adjusts the combustion amount in three stages of high combustion, low combustion, and stop. The combustion apparatus of the present invention includes a blower that supplies combustion air to the combustion chamber. This blower device includes an electric motor including a fan and an air volume control device that is connected to the electric motor and controls the rotational speed of the fan. The air volume control device is not particularly limited, but an inverter is preferably used. The blower supplies three stages of air volume by increasing or decreasing the rotational speed of the fan to a high combustion rotational speed, an ignition rotational speed, and a low combustion rotational speed. The high combustion rotation speed and the ignition rotation speed are set to be higher than the low combustion rotation speed. For the sake of simplicity, this ignition rotation speed can also be used as the same rotation speed as the high combustion rotation speed. By the way, when employing multi-position combustion control other than three-position combustion control, other rotational speeds can be set in addition to these rotational speeds.

  Moreover, the combustion apparatus of this invention is equipped with the damper which controls an air volume by being located in the set opening degree. The opening degree of this damper is at least a high combustion air volume position, a low combustion air volume position whose opening is smaller than the high combustion air volume position, and an ignition air volume position whose opening is even smaller than the low combustion air volume position. Is set. These damper openings are set in consideration of the air volume necessary to obtain a desired air-fuel ratio in relation to the rotational speed of the fan.

  In the first embodiment of the present invention, in the ignition process, the rotation speed of the fan is set as the rotation speed for ignition, and the damper is set as the airflow position for ignition. In the low combustion process, the rotation speed of the fan is set as the rotation speed for low combustion. In the high combustion process, the damper is set to the high combustion rotational speed, and the damper is set to the high combustion air flow position in the high combustion process. Here, the low combustion process and the high combustion process mean a low combustion state process and a high combustion state process, respectively. The gas-fired combustion apparatus includes a pilot ignition process for igniting the pilot burner and a main ignition process for igniting by transferring from the pilot burner to the main burner. The ignition process in this embodiment is the main ignition process. It means an ignition process.

  The low combustion rotational speed is a fan rotational speed set so that an amount of combustion air required for the low combustion process is supplied when the damper is in a low combustion airflow position. In a fully open position, the speed is higher than the rotational speed of the fan, which is the air volume required for the low combustion process. Further, the low combustion air volume position of the damper is an opening degree in a state where the wind pressure generated by the flame is prevented from propagating in the direction of the fan in the low combustion process, and the rotation of the fan. The damper opening is such that combustion air required for the low combustion process is supplied when the speed is the low combustion rotational speed. Thus, in the low combustion process, the fan rotation speed is set to the low combustion rotation speed, and the damper is set to the low combustion air flow position, so that the discharge pressure on the blower side is hardly affected by the wind pressure generated by the flame. A combustion air having a stable air volume can be supplied, and stable combustion can be realized even in a low combustion process.

  Next, according to the second embodiment of the present invention, the ignition process is performed in a state where the rotational speed of the fan is set to the rotational speed for ignition and the damper is set to the airflow position for ignition. Is changed to a low combustion rotational speed, and the damper is opened to the low combustion air volume position after a predetermined time has elapsed from the start of the change of the rotational speed of the fan.

  As a means for opening the damper to the low combustion air volume position after a lapse of a predetermined time from the start of changing the rotation speed of the fan, the time is measured by the time measuring means, and the damper is lowered when the elapsed time reaches the set value. In addition to the means for opening to the combustion air volume position, various sensors detect the air volume of the combustion air supplied by the blower, the rotation speed of the fan, and the frequency signal output from the inverter to the motor, and these detection values are set. Means for opening the damper after a lapse of a predetermined time by switching the damper opening when the value is reached is also included.

  Furthermore, in the first embodiment or the second embodiment, the rotational speed for high combustion and the rotational speed for ignition can be set to the same rotational speed for the rotational speed of the fan of the blower. According to this embodiment, the apparatus can be further simplified.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram of the combustion apparatus of the first embodiment, FIG. 2 is a schematic configuration diagram of a fuel supply device in the combustion apparatus of the first embodiment, and FIG. 3 is a diagram of the combustion apparatus of the first embodiment. It is a time chart of the control to perform.

  As shown in FIG. 1, the combustion apparatus 1 according to the present embodiment controls the air blower 2 that adjusts the air volume by controlling the rotational speed of the fan, and the air volume of the combustion air supplied by the air blower 2. A damper 3 and a fuel supply device 4 that changes the fuel supply amount steplessly are provided, and combustion is performed in the combustion chamber 5. The blower 2, the damper 3, and the fuel supply device 4 are controlled based on a control signal from the control unit 6. In the present invention, the type of fuel is not limited, but the combustion apparatus 1 of the present embodiment is an oil-fired boiler.

  The air blower 2 includes an electric motor 7 having a fan (not shown) and an inverter 8 connected to the electric motor 7 and controlling the fan rotation speed. From the inverter 8 based on a control signal from the control unit 6. The fan rotation speed is controlled by changing the output frequency signal. In this embodiment, as the frequency signal, a high combustion frequency, an ignition frequency, and a low combustion frequency are set from the highest, and the fan rotation speed when operating at each frequency is set to the high combustion frequency. Rotational speed, ignition rotational speed, low combustion rotational speed. By the way, the ignition frequency may be set to a higher numerical value than the high combustion frequency. In this embodiment, the purge frequency is set to be the same as the ignition frequency.

  The damper 3 is provided in a duct 9 serving as a flow path for combustion air supplied by the blower 2, and controls the air volume of the combustion air by partially closing a cross section of the duct 9. As the damper opening, a high combustion air volume position (90 ° with respect to the direction of the central axis of the duct 9, that is, a direction perpendicular to the air flow direction), and a low combustion air volume whose opening is smaller than the high combustion air volume position. Position (25 ° with respect to the direction perpendicular to the central axis direction of the duct 9) and an ignition air volume position with a smaller opening than the low combustion air volume position (with respect to the direction perpendicular to the central axis direction of the duct 9) 20 degrees) are set.

  Next, the fuel supply device 4 of the present embodiment will be described with reference to FIG. The fuel supply device 4 includes a fuel pump (not shown), a fuel tank (not shown), a first fuel valve 10, a second fuel valve 11, a flow rate adjusting valve 12, a transition valve 13, a low combustion nozzle 14 and a high Combustion nozzles 15 are provided, which are connected to each other through fuel flow paths 16, 17 and 18. The first fuel channel 16 is connected to a fuel pump and a fuel tank, and the fuel flows through the first fuel channel 16 in the direction of the arrow. A first fuel valve 10 is provided in the first fuel flow path 16, and is connected to a low combustion nozzle 14 at a downstream end of the first fuel valve 10. The fuel flow path branches from the first fuel flow path 16 to the second fuel flow path 17 and the third fuel flow path 18 on the upstream side of the first fuel valve 10. The second fuel flow path 17 is provided with the second fuel valve 11, and the third fuel flow path 18 is provided with the flow rate adjustment valve 12 and the transition valve 13 from the upstream side, and on the upstream side of the flow rate adjustment valve 12. Is provided with an orifice 19 for adjusting the amount of fuel supplied to the high combustion nozzle 15. The second fuel flow path 17 and the third fuel flow path 18 merge together on the downstream side of the second fuel valve 11 and the transition valve 13 and are connected to the high combustion nozzle 15 at the end. In the present embodiment, the transition valve 13 is disposed on the downstream side of the flow rate adjustment valve 12 in the third fuel flow path 18, but the transition valve 13 may be disposed on the upstream side of the flow rate adjustment valve 12.

  As the first fuel valve 10, the second fuel valve 11, and the transition valve 13, electromagnetic valves controlled by two operations of opening and closing are used. The flow rate adjusting valve 12 is a valve device capable of steplessly changing the size of the flow path cross-sectional area of the third fuel flow channel 18, and passes through the flow rate adjusting valve 12 and is a high combustion nozzle. The amount of fuel supplied to 15 can be changed steplessly. However, the flow rate adjusting valve 12 can be applied to any type as long as the amount of fuel passing therethrough can be changed steplessly. The transition valve 13 switches the presence or absence of fuel supply that passes through the flow rate adjustment valve 12.

  Next, a control method in the present embodiment that is executed by the control unit 6 will be described with reference to FIG. When the combustion apparatus 1 of this embodiment is activated, the blower 2 starts operation, the fan rotation speed is increased to the ignition rotation speed, and pre-purge is performed. During the pre-purge, the damper opening is set to the high combustion air volume position.

  After the pre-purge is performed for a predetermined time, the blower 2 is closed to the ignition air volume position while maintaining the fan rotation speed at the ignition rotation speed, and the process proceeds to the ignition process. In the ignition process, first, the ignition device is activated, the first fuel valve 10 is opened after a predetermined time has elapsed since the activation of the ignition device, and fuel supply is started. During this time, the ignition device is continuously activated, and is stopped after a predetermined time has elapsed since the start of fuel supply. By the way, the period from the start of the ignition device to the start of fuel supply is called pre-ignition, and the period from the start of fuel supply to the stop of the ignition device is called ignition try. An ignition process is configured.

  After the ignition process is completed, the state where the fan rotation speed is set to the ignition rotation speed and the damper opening is set to the ignition airflow position is continued for a predetermined time. Then, it shifts to a low combustion process. First, the air blower 2 starts changing the fan rotation speed to the low combustion rotation speed. Then, the elapsed time from the change start time of the fan rotation speed is measured by the time measuring means, and when the elapsed time reaches the set time T1, the damper 3 is opened to the low combustion air volume position. In this embodiment, the opening and closing speed of the damper 3 is slow, and as shown in FIG. 3, it is configured to change from the ignition air volume position to the low combustion air volume position at time T1. However, when the opening / closing speed of the damper 3 is fast, the damper 3 can be configured to open during the change of the fan rotation speed.

  In the low combustion process, the fan rotation speed is set to the low combustion rotation speed, and the damper opening is set to the low combustion air volume position. As a result, the combustion air having the air volume necessary for the low combustion process is supplied, and the discharge pressure on the blower 2 side can be hardly affected by the wind pressure generated by the flame. Stable combustion can be performed. Further, in the low combustion process, an amount of fuel necessary for low combustion is supplied to the low combustion nozzle 14 through the first fuel valve 10.

  When shifting from the low combustion process to the high combustion process, first, the flow rate adjusting valve 12 and the transition valve 13 are opened, and the time measuring means measures the elapsed time from when the transition valve 13 is opened, and the set time T2 Then, the blower 2 starts changing the fan rotation speed from the low combustion rotation speed to the high combustion rotation speed. This set time T2 is set to a time comparable to the time required from the start of the valve opening operation of the flow rate adjusting valve 12 until the fuel is actually supplied to the high combustion nozzle 15. By the way, when the time difference from the start of the valve opening operation of the flow rate adjusting valve 12 until the fuel is actually supplied to the high combustion nozzle 15 can be ignored, the set time T2 may not be provided.

  In this embodiment, an inverter 8 is used as an air volume control device, and the fan rotation speed is controlled to increase in proportion to the elapsed time. The flow rate adjusting valve 12 increases the fuel supply amount steplessly so as to maintain a desired air-fuel ratio in response to the increase in the fan rotation speed. The fuel supplied to the high combustion nozzle 15 through the flow rate adjusting valve 12 passes through the first fuel valve 10 when the fan rotational speed reaches the high combustion rotational speed. 14 is set so as to be the amount necessary for the high combustion process.

  Moreover, the elapsed time from the time when the transition valve 13 is opened is measured by the time measuring means, and when the elapsed time reaches the set time T3, the transition valve 13 is closed. The set time T3 is set to approximately the same time as the sum of the set time T2 and the time T4 required for the fan rotation speed to reach the high combustion rotation speed from the low combustion rotation speed. By the way, instead of the time measuring means, the air volume of the combustion air, the rotation speed of the fan, the frequency signal output from the inverter 8 to the electric motor 7 and the like are detected by various sensors, and these detected values reach the set values. The transition valve 13 may be closed at the time.

  On the other hand, the flow regulating valve 12 is maintained in the open state even during the high combustion process after the transition valve 13 is closed. In the present embodiment, the first fuel valve 10 is also closed and the second fuel valve 11 is opened simultaneously with the transition valve 13 being closed. That is, in the high combustion process, an amount of fuel necessary for the high combustion process is supplied to the high combustion nozzle 15 only through the second fuel flow path 17, and the fuel is supplied to the low combustion nozzle 14. Not done. Thus, in the high combustion process, fuel is sprayed into the combustion chamber 5 only from the high combustion nozzle 15, so that the fuel sprayed from both nozzles 14, 15 does not interfere with each other and cause poor combustion. , Better combustion can be performed. In addition, since the flow rate adjusting valve 12 is used only at the time of transition of the fan rotation speed in this way, clogging of the flow path caused by the flow rate adjusting valve 12 can be effectively prevented, Stable operation with less can be realized.

  At the same time, the damper 3 is opened to the high combustion air volume position simultaneously with the start of changing the fan rotation speed from the low combustion rotational speed to the high combustion rotational speed. In this embodiment, the opening and closing speed of the damper 3 is slow, and as shown in FIG. 3, the damper 3 is configured to open from the low combustion air volume position to the high combustion air volume position at time T4. Since the flow rate adjustment valve 12 gradually increases the amount of fuel supplied to the high combustion nozzle 15 in response to the gradual increase in air volume caused by the change in the damper opening and the change in the fan rotation speed, that is, a smooth increase. Stable combustion can be performed without destroying the air-fuel ratio. In this embodiment, the damper 3 is configured to change from the low combustion airflow position to the high combustion airflow position at time T4. However, when the opening / closing speed of the damper 3 is fast, the fan rotation speed is changed. It can also be configured to start opening the damper 3 in the middle.

  In the high combustion process, the fan rotation speed of the blower 2 is maintained at the high combustion rotation speed while the damper opening is at the high combustion airflow position.

  When shifting from the high combustion process to the low combustion process, the first fuel valve 10 and the transition valve 13 that were in the closed state are first opened, and at the same time, the second fuel valve 11 is closed. Thus, fuel is supplied to the nozzles 14 and 15 through the first fuel passage 16 and the third fuel passage 18 instead of the second fuel passage 17. And the elapsed time from the time when the transition valve 13 is opened is measured by the time measuring means, and when the elapsed time reaches the set time T5, the fan rotation speed of the blower 2 is reduced from the high combustion rotation speed. The transition to the rotational speed for combustion is started. This set time T5 is approximately the same as the time required from when the transition valve 13 is opened until the fuel is actually supplied to the high combustion nozzle 15. By the way, when the time difference from when the transition valve 13 is opened to when the fuel is actually supplied to the high combustion nozzle 15 can be ignored, the set time T5 may not be provided.

  The change of the fan rotation speed is controlled by the inverter 8 so as to decrease in proportion to the elapsed time. Then, the flow rate adjusting valve 12 reduces the fuel supply amount steplessly so as to maintain a desirable air-fuel ratio in response to the decrease in the fan rotation speed.

  Further, the elapsed time from the time when the transition valve 13 is opened is measured by the time measuring means, and when the elapsed time reaches the set time T6, the flow rate adjusting valve 12 and the transition valve 13 are closed. The set time T6 is set to a time comparable to the sum of the set time T5 and the time T7 required for the fan rotational speed to reach the low combustion rotational speed from the high combustion rotational speed. By the way, instead of the time measuring means, the air volume of the combustion air, the rotation speed of the fan, the frequency signal output from the inverter 8 to the electric motor 7 and the like are detected by various sensors, and these detected values reach the set values. The flow rate adjustment valve 12 and the transition valve 13 may be closed at the time.

  At the same time, the damper 3 is closed to the low combustion air volume position simultaneously with the start of the change of the fan rotational speed from the high combustion rotational speed to the low combustion rotational speed. In this embodiment, the opening and closing speed of the damper 3 is slow, and as shown in FIG. 3, it is configured to close from the high combustion air volume position to the low combustion air volume position at time T7. Since the flow rate adjustment valve 12 gradually reduces the amount of fuel supplied to the high combustion nozzle 15 in response to the gradual decrease of the air volume caused by the change in the damper opening and the change in the fan rotation speed, that is, the smooth decrease. Stable combustion can be performed without losing the air-fuel ratio. In this embodiment, the damper 3 is configured to change from the high combustion airflow position to the low combustion airflow position at time T7. However, when the opening / closing speed of the damper 3 is fast, the fan rotation speed is changed. It can also be configured such that the damper 3 begins to close in the middle.

  Completion of combustion is performed following the low combustion process, the first fuel valve 10 is closed, and the fan rotation speed of the blower 2 is shifted from the low combustion rotation speed to the ignition rotation speed, and the damper is opened. The post-purge is continued for a predetermined time in a state where the degree is set to the high combustion air volume position and the rotation speed for ignition is kept as it is. Thereafter, the blower 2 is stopped. In this way, the combustion device 1 stops operating. The post purge can be omitted as necessary.

  According to the first embodiment, stable combustion can be realized at the time of transition from the ignition process to the low combustion process and in the low combustion process, and a combustion apparatus excellent in combustibility can be provided. In addition, stable combustion is possible even if the air volume of combustion air and the fuel supply amount in the low combustion process are reduced, and the turndown ratio can be increased. Further, since the fuel supply amount is made the same by performing fuel supply through the first fuel valve 10 in common in the ignition process and the subsequent low combustion process, the ignition process can be performed by reducing the fuel supply amount in the low combustion process. The fuel supply amount can be reduced at the same time, and the ignition shock can be further suppressed.

  Next, a second embodiment of the present invention will be described. FIG. 4 is a time chart of control executed by the combustion apparatus of the second embodiment. In the second embodiment, the configuration of the combustion device 1 shown in FIG. 1 and the configuration of the fuel supply device 4 shown in FIG. 2 are common to the combustion device 1 of the first embodiment.

  The second embodiment is different from the first embodiment in that the first fuel valve 10 is continuously opened during combustion. Therefore, in the high combustion process, unlike the combustion device 1 of the first embodiment, the first fuel valve 10 is not closed, and the fuel that passes through the first fuel valve 10 and is supplied to the low combustion nozzle 14. And the amount of fuel that passes through the second fuel valve 11 and is supplied to the high combustion nozzle 15 is the fuel supply amount required for the high combustion process. In this case, fuel is sprayed from both the low combustion nozzle 14 and the high combustion nozzle 15 into the combustion chamber 5 at the same time. However, in order to perform good combustion, the fuel is sprayed from the nozzles 14 and 15. It is desirable to take measures to prevent the fuels from interfering with each other.

  As mentioned above, although the Example of this invention was described, this invention is not limited to the structure of the said Example, It can change suitably. In particular, in the two embodiments described above, the combustion apparatus 1 that changes the fuel supply amount steplessly at the time of transition of the fan rotation speed has been described. However, the present invention is not limited to this, The present invention can also be applied to a combustion apparatus that changes the fuel supply amount in two stages of a combustion process and a low combustion process. Furthermore, the damper 3 may be configured to be fully closed when the combustion is stopped, and may be configured to prevent heat dissipation from the boiler body (not shown).

It is a schematic block diagram of the combustion apparatus in one Example of this invention. It is a schematic block diagram of the fuel supply apparatus in one Example of this invention. It is a figure which shows the control chart of the 1st Example in this invention. It is a figure which shows the control chart of the 2nd Example in this invention. It is a figure which shows the control chart in the conventional combustion apparatus.

Explanation of symbols

1 Combustion device 2 Blower device 3 Damper

Claims (3)

The air volume is adjusted by controlling the rotational speed of the fan to at least a high combustion rotational speed, an ignition rotational speed, or a low combustion rotational speed that is lower than the high combustion rotational speed and the ignition rotational speed. A blower (2);
By disposing at least the high combustion airflow position, the low combustion airflow position having a smaller opening than the high combustion airflow position, or the ignition airflow position having a smaller opening than the low combustion airflow position, A damper (3) for controlling the air volume from the blower (2), and
In the ignition step, the rotation speed of the fan is set as the rotation speed for ignition, and the damper (3) is set as the airflow position for ignition.
In the low combustion process, the rotational speed of the fan is the low combustion rotational speed, and the damper (3) is the low combustion air flow position,
In the high combustion process, the rotational speed of the fan is a high combustion rotational speed, and the damper (3) is a high combustion air volume position. An ignition process is performed in a state where the rotational speed of the fan is set to the rotational speed for ignition and the damper (3) is set to the ignition air volume position. After the ignition process is completed, the blower (2) The change to the low combustion rotational speed is started, and the damper (3) is opened to the low combustion air flow position after a predetermined time has elapsed from the start of the change of the rotational speed of the fan. The combustion apparatus according to 1. The combustion apparatus according to claim 1 or 2, wherein the fuel supply amount in the ignition process and the subsequent low combustion process are the same.

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