JP3739611B2 - Combustion device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a combustion apparatus including a small capacity burner unit that performs heating or reheating, and a large capacity burner unit that performs hot water supply.
[0002]
[Prior art]
Conventionally, in this type of combustion apparatus, in order to reduce the size without degrading the performance, the large capacity burner exhaust pipe and the small capacity burner exhaust pipe are combined into one collective exhaust pipe that communicates with the outside. Although the number of burners constituting the burner portion is reduced, the ability of the combustion apparatus is maintained by increasing the gas ejection speed. Further, in order to improve the throttle characteristics of the high-capacity burner section, the large-capacity burner section is configured to be able to switch between full combustion and partial combustion by changing the number of burners.
[0003]
By the way, when the burner is ignited from a cold state (so-called cold start), the temperature of the fuel gas and combustion air ejected from the burner is low, the combustion speed becomes slow, the flame becomes unstable, and the burner vibrates. Burn. The vibration combustion has a large capacity burner with a large capacity burner when a large capacity burner with a large number of burners and a high gas ejection speed (a large combustion load of the burner) is ignited entirely during combustion of the small capacity burner. Combustion exhaust gas from the high-capacity burner part that started combustion can be suppressed by the influence of the combustion exhaust from the small-capacity burner part during combustion by the structure that combines the capacity exhaust pipe into one collective exhaust pipe. As a result, there is a problem that abnormal noise based on vibration combustion occurs in the combustion apparatus.
[0004]
Such a problem can be avoided, for example, by increasing the number of burners and decreasing the gas ejection speed, but this method is contrary to the above-described miniaturization of the water heater.
[0005]
As another solution, from Japanese Patent Application Laid-Open No. 11-108354, when a combustion start signal of a hot water supply burner that is a large-capacity burner is input during combustion of a heating burner that is a small-capacity burner, It is known to provide an ignition control device in a water heater with a heating function that minimizes the amount of combustion of the heating burner within a controllable range, or temporarily stops the combustion of the heating burner for a predetermined time.
[0006]
[Problems to be solved by the invention]
However, in this ignition control device, when the ignition signal of the hot water burner is inputted during the combustion of the heating burner, the combustion amount of the heating burner is uniformly minimized or the combustion is stopped. This is unnecessary even when the ignition is partially ignited, that is, when the combustion capacity is small and the gas ejection speed is slow and it is difficult to generate abnormal noise due to vibration combustion even if it is affected by the heating burner. There was a problem of limiting the capacity of the heating burner.
[0007]
Therefore, the present invention provides a combustion apparatus that prevents the generation of abnormal noise based on vibration combustion of a large-capacity burner while preventing the capacity limitation of an unnecessary small-capacity burner without increasing the size of the combustion apparatus. is there.
[0008]
[Means for Solving the Problems]
The invention of claim 1, wherein in order to solve this problem, the entire combustion and partial combustion and that can toggle between water heater burner unit and the hot water supply burner unit exhaust stack hot water supply burner for discharging combustion exhaust gas due to combustion of the comprising a large capacity portion, and a small capacity part and a heating or reheating burner unit and said heating or reheating heating or reheating burner stack for discharging combustion exhaust gas due to the combustion of the burner unit having a hot water supply In a combustion apparatus in which a burner exhaust pipe and a heating or reheating burner exhaust pipe are connected to a single collective exhaust pipe that communicates with the outside, an ignition operation for burning the entire hot water supply burner during heating or reheating burner combustion Or after performing an ignition operation for burning the hot water supply burner part entirely, after heating or reheating the burner part within a predetermined time, heating or reheating for a predetermined time Burner And limits the fuel gas flow rate below a predetermined flow rate.
[0009]
Thus, after the ignition operation for entirely burned hot water supply burner unit during heating or reheating burner combustion, or the hot water supply burner unit even after performing the ignition operation to be entirely burned, heating or within a predetermined time After the ignition operation of the additional burner unit, a predetermined time until combustion of the hot water supply burner unit, that is, the large-capacity burner unit is stabilized, the fuel gas to the heating or additional burner unit, that is, the small-capacity burner unit Since the flow rate is limited and the influence of combustion exhaust from the small capacity burner portion is reduced, vibration combustion at the initial stage of ignition of the large capacity burner portion is not promoted, and the generation of abnormal noise is prevented. In this case, it is preferable that the restriction on the flow rate of the fuel gas is released in stages. As a result, the flame of the high-capacity burner part gradually becomes in a stable combustion state with the passage of time, and accordingly the restriction of the fuel gas flow rate to the small-capacity burner part is released step by step, whereby the small-capacity burner part can be the combustion capability is reduced as much as possible the time is reduced to improve the usability of the combustion apparatus.
[0010]
The invention described in claim 3 is a large-capacity burner unit capable of switching between full combustion and partial combustion, a high-capacity burner combustion fan for supplying air necessary for combustion to the large-capacity burner unit, and the large burner unit. A large-capacity burner having a large-capacity burner exhaust cylinder that discharges combustion exhaust gas accompanying combustion of the capability burner section, a small-capacity burner section, and a small-capacity burner that discharges combustion exhaust gas accompanying combustion of the small-capacity burner section And a small capacity burner having a small capacity portion having a small capacity burner, wherein the large capacity burner exhaust cylinder and the small capacity burner exhaust cylinder are connected to one collective exhaust pipe that communicates with the outside. After performing an ignition operation to burn the entire large capacity burner part or after performing an ignition operation to burn the entire large capacity burner part, the ignition operation of the small capacity burner part is performed within a predetermined time. After a certain time, Daino The rotational speed of the combustion fan burner, primary air amount supplied to the large capacity burner portion is controlled so as to approach the theoretical amount of air, characterized in that to increase the burn rate.
[0011]
As a result, after performing the ignition operation to burn the entire large capacity burner during the small capacity burner, or after performing the ignition operation to burn the entire large capacity burner, After the ignition operation of the burner part, set the rotation speed of the combustion fan for the high-capacity burner for a predetermined time until the combustion of the high-capacity burner is stabilized so that the primary air amount to the high-capacity burner approaches the theoretical air amount The high-capacity burner is stably combusted by increasing the combustion speed to suppress the vibration combustion of the high-capacity burner section that occurs in the early stage of ignition, and the influence of combustion exhaust from the small-capacity burner section during combustion is suppressed. Even if it is received, the generation of abnormal noise due to combustion of the high-capacity burner is prevented. In this case, it is preferable to release the control of the rotation speed of the combustion fan for the large-capacity burner step by step. As a result, the flame of the high-capacity burner gradually becomes stable with the passage of time from ignition, so by releasing the control of the rotation speed of the combustion fan for the high-capacity burner step by step, It is possible to reduce the time during which fan noise, which is larger than that in the capacity burner combustion, is generated as much as possible, and to improve the usability of the combustion apparatus.
[0012]
Also, when an ignition operation is performed to burn the entire large capacity burner during the small capacity burner or after an ignition operation is performed to burn the entire large capacity burner, Combining the restriction of the fuel gas flow rate to the small capacity burner and the control of the rotation speed of the combustion fan for the large capacity burner when the ignition operation of the small capacity burner is performed within a predetermined time until stabilization. You can also. As a result, the generation of the abnormal sound is prevented, the capacity limitation of the small capacity burner is suppressed, and the generation of fan noise accompanying the rotation speed control of the large capacity burner is suppressed while maintaining the capacity of the small capacity burner to some extent. It is possible to improve usability. Also in this case, it is preferable to release the restriction on the flow rate of the fuel gas to the small capacity burner and the control of the rotational speed of the combustion fan for the large capacity burner step by step.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram schematically showing the configuration of a water heater with a heating function as the combustion apparatus of the present invention. The water heater 1 with a heating function includes a hot water supply unit 2 and a heating unit 3 in which an ignition operation and the degree of opening and closing of a solenoid valve are controlled by a control unit 6. The hot-water supply unit 2 basically includes a hot-water supply burner unit 21 capable of switching between full combustion and partial combustion, a hot-water supply heat exchanger 22 disposed above the hot-water supply burner unit 21, and the hot-water supply burner unit 21. A hot water supply combustion fan 23 which is disposed below the hot water supply burner section 21 and which supplies combustion air to the hot water supply burner section 21 and includes a motor (not shown) whose rotational speed can be controlled by a signal from the control unit 6. And a hot water supply exhaust cylinder 24 that discharges combustion exhaust gas accompanying combustion of the hot water supply burner unit 21.
[0014]
The hot water supply burner unit 21 includes, for example, a plurality of main flame ports arranged in a flat portion on the upper surface, and auxiliary flame ports provided on both sides of the main flame port, and a gas distribution chamber below these flame ports. And a plurality of Bunsen burners provided with a mixing tube communicating with the gas distribution chamber are arranged in parallel and accommodated in the burner case. In addition, a fuel gas supply pipe 26 having a gas proportional valve 27 whose degree of opening and closing can be adjusted is connected to each fuel gas supply section at the end of the mixing pipe of each burner via a hot water supply manifold (not shown). The fuel gas can be supplied to each burner at the same time, but the fuel gas supply pipe 26 is one that is branched from the original gas pipe 5 provided with an electromagnetic valve into two. In the middle of the path of the fuel gas supply pipe 26, the electromagnetic valves 25 are provided. As a result, the hot water supply burner unit 21 can switch between full surface combustion and partial combustion of the hot water supply burner unit by controlling the electromagnetic valve 25.
[0015]
The heating unit 3 is basically configured in the same manner as the hot water supply unit 2, and includes a heating burner unit 31 in which some Bunsen type burners are arranged in parallel with the hot water supply burner unit 21, and the heating burner unit 31. It has a heating heat exchanger 32 disposed above, a heating combustion fan 33 equipped with a motor, and a heating exhaust cylinder 34 that discharges combustion exhaust gas accompanying combustion in the heating burner section. A fuel gas supply pipe 36 branched from the original gas pipe 5 is connected to the fuel gas supply section at the end of the mixing pipe of each burner via a heating manifold (not shown). An electromagnetic valve 35 and a gas proportional valve 37 whose degree of opening and closing can be adjusted are provided in the middle of the pipe path. Further, the hot water supply exhaust pipe 24 on the hot water supply section side and the heating exhaust pipe 34 on the heating section side are connected to one collective exhaust pipe 4 communicating with the outside.
[0016]
Next, the ignition control attached to the control unit 6 of the water heater with a heating function will be described with reference to FIG.
[0017]
The ignition control is performed by the control unit 6 from the control unit 6 to the full ignition of the hot water supply burner unit 21 (when the hot water supply burner unit is fully ignited from the extinguishing state, or when the partial combustion is already switched to the full combustion mode) When the signal is received, first, it is confirmed whether or not the heating burner unit 31 of the heating unit 3 is in combustion. When the heating burner unit is in combustion, the entire surface of the hot water supply burner unit is ignited and the flow rate of the fuel gas supplied to the heating burner unit 31 is reduced by reducing the opening of the gas proportional valve 37 of the heating unit 3. Limit for a predetermined time. In this case, the fuel gas flow rate is limited by the gas proportional valve 37 in a range up to 2/3 of the maximum fuel gas flow rate. The reason why the fuel gas flow rate is limited to 2/3 of the maximum fuel gas flow rate is that within the above range, the heating burner unit 31 is maintained at a high level to a certain extent, and the heating burner unit 21 with respect to the hot water supply burner unit 21 is maintained. This is because the influence of the combustion exhaust gas is reduced, vibration combustion at the initial stage of ignition of the hot water supply burner portion 21 is not promoted, and abnormal noise can be prevented. At that time, when the set heating capacity determined by the room temperature set in the control unit 6 requires a fuel gas flow rate of 2/3 or more of the maximum fuel gas flow rate, the heating burner unit 31 is supplied to the heating unit 31 according to the set heating capacity. The flow rate of the fuel gas is limited, and the number of revolutions of the motor of the hot water supply combustion fan 23 is increased to increase the amount of primary air supplied to the hot water supply burner unit 21 so as to approach the theoretical air amount. In this case, the rotational speed of the motor is controlled in a range of about + 5% of the rotational speed of the motor in the normal combustion state of the hot water supply burner unit 21. The reason why the rotational speed of the motor is controlled within this range is that the noise of the fan, which is larger than that during normal hot water supply burner combustion, can be reduced as much as possible while preventing the occurrence of the abnormal noise described above. In this embodiment, since the hot water supply burner unit 21 is composed of a Bunsen burner, control is performed so as to increase the rotation speed of the hot water supply combustion fan 23. For example, the hot water supply burner unit 21 is usually connected to theoretical air. In the case where the primary air burner is set to be supplied with a primary air amount that is greater than or equal to the amount, the primary air supplied to the hot water supply burner unit 21 by reducing the rotational speed of the hot water supply combustion fan 23. Reduce the amount and control to approach the theoretical air amount. Then, the solenoid valve 25 is opened to ignite the hot water supply burner unit 21 entirely. In this embodiment, the case where the restriction of the flow rate of the fuel gas to the heating burner unit 31 and the control of the rotation speed of the hot water supply combustion fan 23 are combined is described. However, the fuel gas to the heating burner unit 31 is described. The restriction of the flow rate or the control of the number of revolutions of the hot water supply combustion fan 23 can be performed independently.
[0018]
The lower side of FIG. 2 shows a flowchart in the case where the ignition operation of the heating burner unit 31 is performed within a predetermined time after the ignition operation for burning the entire hot water supply burner unit 21 is performed. The same control as described above is performed.
[0019]
In addition, a timer may be attached to the control unit 6 so that the restriction of the flow rate of the fuel gas to the heating burner unit 31 and the control of the rotational speed of the motor of the hot water supply combustion fan are gradually released as time passes. it can. In this case, the timer is started simultaneously with the ignition of the hot water supply burner unit 21, and the restriction on the flow rate of the fuel gas to the heating burner unit 31 is released based on the equation (2TX + Xt) / (3T). Here, T is the fuel gas flow rate limit time to the heating burner unit 31 set in the timer, t means the elapsed time from the start of the timer, and the relationship of 0 ≦ t ≦ T is established. X is the maximum fuel gas flow rate. Control of the rotation speed of the motor of the hot water supply combustion fan is canceled based on the formula of (105BT-5Bt) / 100T when the hot water supply burner section is constituted by a Bunsen burner. Here, T is the rotation speed control time of the motor for the hot water supply combustion fan to the hot water supply burner unit 21 set in the timer, t means the elapsed time from the start of the timer, and the relationship 0 ≦ t ≦ T Is established. B is the number of rotations of the motor in the normal operation state.
[0020]
In the above-described embodiment, the heating burner is described as the small capacity burner. However, the small capacity burner may be a reheating burner used for a hot water heater with a reheating function. Further, in the control shown in FIG. 2, when there is an instruction to ignite the hot water supply burner, once partial combustion is performed, switching to full combustion is performed according to the required hot water supply capacity. The present invention can also be applied to control in which the entire surface is ignited and then switched to partial combustion according to the required hot water supply capacity.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a configuration of a water heater with a heating function according to the present invention.
FIG. 2 is a simplified flowchart showing ignition control according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hot water heater with a heating function 2 Hot water supply part 21 Hot water supply burner part 22 Hot water supply heat exchanger 23 Hot water supply combustion fan 24 Hot water supply exhaust pipe 25, 35 Solenoid valve 27, 37 Gas proportional valve 3 Heating part 31 Heating burner part 32 Heating heat exchange 33 Heating combustion fan 34 Heating exhaust cylinder 4 Collective exhaust cylinder 5 Original gas pipe

Claims (4)

A large capacity portion and a entire surface combustion and that can toggle between water heater burner portion of the partial combustion and the hot water supply burner unit water heater burner exhaust pipe for discharging the combustion exhaust gas due to the combustion of the heating or reheating burner unit and said and a small capacity part and a heating or reheating burner stack for discharging combustion exhaust gas due to the combustion of the heating or reheating burner unit, and the the hot water supply burner stack heating or reheating burner stack In a combustion apparatus connected to one collective exhaust pipe communicating with the outside, after performing an ignition operation for burning the entire hot water burner during heating or reheating burner combustion, or an ignition operation for burning the entire hot water burner And after the ignition operation of the heating or additional burner unit is performed within a predetermined time, the fuel gas flow rate to the heating or additional burner unit is limited to a predetermined flow rate or less for a predetermined time. thing Combustion apparatus according to claim.   The combustion apparatus according to claim 1, wherein the restriction on the flow rate of the fuel gas is released in stages. A high-capacity burner unit capable of switching between full combustion and partial combustion, a high-capacity burner for supplying air necessary for combustion to the high-capacity burner unit, and combustion exhaust gas accompanying combustion of the high-capacity burner unit A large capacity portion having a large capacity burner exhaust cylinder that discharges a small capacity burner section, and a small capacity section having a small capacity burner section and a small capacity burner exhaust cylinder that discharges combustion exhaust gas accompanying combustion of the small capacity burner section; A combustion apparatus in which the large capacity burner exhaust pipe and the small capacity burner exhaust pipe are connected to one collective exhaust pipe that communicates with the outside.
After performing an ignition operation that burns the entire large capacity burner during the small capacity burner or after performing an ignition operation that burns the entire large capacity burner, After performing the ignition operation, the rotational speed of the combustion fan for the large-capacity burner is controlled so that the primary air amount supplied to the large-capacity burner unit approaches the theoretical air amount for a predetermined time to increase the combustion speed. Combustion device characterized by that.   The combustion apparatus according to claim 3, wherein the control of the rotational speed of the combustion fan for the high-capacity burner is canceled in a stepwise manner.

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