JPH07260142A - Combustion apparatus - Google Patents

Abstract

PURPOSE:To reduce contamination in a chamber with combustion gas which has a fear of occurring due to combustion of a burner as much as possible. CONSTITUTION:A combustion apparatus has a fan 4 for ventilating combustion air to a burner 2 and exhausting combustion gas out of a chamber through an exhaust passage 5 and control means 101 for stopping the combustion of the burner 2 according to a command of stopping the combustion and executing a post-purging for continuing an operation of the fan 4 for a predetermined time even after the combustion of the burner 2 is stopped, and comprises clock means 102 for counting the combustion continuing time of the burner 2. The means 101 is so constructed as to set to alter a time for executing the post- purging longer as the continuing time is longer based on counting information of the means 102.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided with ventilation means for ventilating combustion air to a burner and discharging combustion gas to the outside through an exhaust passage, and to burn the burner in response to a command to stop combustion. The present invention relates to a combustion device provided with control means for executing post-purge for stopping the operation of the ventilation means for a predetermined time even after the combustion of the burner is stopped.

[0002]

2. Description of the Related Art In the above combustion apparatus, conventionally, the operation time of the post-purge executed after the combustion of the burner is stopped in response to a command to stop the combustion is the combustion accumulated in the apparatus after the combustion of the burner is stopped. It was set to a fixed time required to discharge the gas to the outside.

[0003]

In the combustion apparatus having the above-mentioned structure, for example, when the exhaust passage is blocked by dust or the like, the combustion gas may leak into the room. The longer the combustion duration of the burner, the more the combustion gas may leak into the room. However, in the above conventional structure, since the post-purge operation time after the combustion of the burner is stopped is a constant value as described above, when the combustion gas leaks into the chamber as described above, If the combustion duration is long and the amount of the leaked combustion gas is large, the exhaust treatment of the leaked combustion gas becomes insufficient.
As a result, in such a case, it is necessary to purify the room air by natural ventilation such as opening the window of the room, but if such a ventilation operation is neglected, especially in a small room, a highly sealed room, etc. In this case, it is considered that the pollution situation due to the combustion gas will continue for a long time with a relatively high degree of pollution, and there is a possibility that the adverse effect on the human body cannot be eliminated, and there is room for improvement in this respect. The present invention has been made in view of this point, and an object thereof is to provide a combustion device capable of minimizing indoor pollution due to combustion gas, which may occur due to combustion of a burner. To provide.

[0004]

The features of the first invention are as follows:
The burner is provided with ventilation means for ventilating the combustion air and discharging the combustion gas to the outside through the exhaust passage. The combustion of the burner is stopped in accordance with the instruction to stop the combustion, and the combustion of the burner is stopped. In the combustion apparatus provided with the control means for executing the post-purge for continuing the operation of the ventilation means for a predetermined time even after the operation, the time keeping means for counting the combustion duration of the burner is provided, and the control means is
The point is that the time for executing the post-purge is changed and set longer as the combustion duration time is longer, based on the time information of the time measuring means.

The characteristic configuration of the second aspect of the invention specifies a preferable configuration for implementing the characteristic configuration of the first aspect of the invention, in which the control means continues the post-purge for a predetermined time at the maximum ventilation amount. After that, it is executed in a form in which the amount of ventilation is smaller than the maximum amount of ventilation for a time longer than the predetermined time, and the maximum ventilation amount duration time in the post-purge is changed to be set longer as the combustion duration time is longer. It is a point that is configured.

A characteristic configuration of a third invention is the first or second aspect.
A preferred configuration is specified in the implementation of the characteristic configuration of the invention, wherein a fuel supply amount integrating means for determining an integrated value of the fuel supply amount to the burner in the combustion duration of the burner is provided, and the control means is provided. The larger the integrated value of the fuel supply amount integrating means is, the longer the post-purge execution time is set to be changed.

[0007]

According to the characterizing feature of the first invention, the combustion duration time from the start of the combustion operation of the burner to the combustion stop time is measured, and the longer the duration is, the more the ventilation operation of the ventilation means after the combustion is stopped [post purge]. ], The operating time becomes longer. That is, if the combustion gas leaks into the room, it is considered that the longer the combustion duration is, the larger the amount of the leakage combustion gas is. Therefore, in the state where the combustion of the burner is stopped and the generation of the combustion gas is suppressed, the post-purge is executed for a longer time as the combustion duration is longer, so that the combustion gas remaining in the device when the combustion of the burner is stopped Not only can the exhaust gas be discharged outside the room, but also the combustion gas leaking into the room can be discharged outside the room accurately.

According to the characterizing feature of the second aspect of the invention, when the combustion of the burner is stopped, the longer the burner combustion duration is, the longer the predetermined time that is set to be changed is changed. Even if the combustion gas leaks into the room, the longer the duration of combustion, the longer the post-purge with the maximum air flow will be executed. It is possible to discharge the combustion gas leaking indoors to the outside reliably due to the strong wind force. After that, when the post-purge is continued for a time longer than the predetermined time with a ventilation volume smaller than the maximum ventilation volume, the combustion operation is restarted while suppressing the noise caused by the ventilation to a small level. In addition, the start-up drive of the ventilation means is quickly performed, and the burner combustion operation can be appropriately performed in a short time.

According to the characteristic construction of the third aspect of the invention, when the combustion gas leaks into the room, the larger the integrated value of the fuel supply amount during the combustion duration of the burner, the larger the leakage amount of the combustion gas. It is conceivable that, as the integrated value of the fuel supply amount is larger, the post-purge is executed for a longer time, so that the combustion gas leaked into the room can be reliably discharged to the outside of the room.

[0010]

According to the characterizing feature of the first aspect of the invention, the longer the combustion duration of the burner is set, the longer the post purge execution time is set. It has become possible to provide a combustion device capable of discharging the leaked combustion gas to the outside of the room and improving safety.

According to the characterizing structure of the second invention, in addition to the effect of the characterizing structure of the first invention, the combustion gas remaining in the apparatus and the combustion gas leaking into the room can be reliably discharged to the outside by the strong wind force. When the burner combustion is stopped and restarted within a short time after the combustion of the burner is stopped, the start-up drive of the ventilation means to a predetermined ventilation volume can be performed quickly while suppressing noise to a low level. Thus, the burning operation of the burner can be properly performed in a short time.

According to the characterizing feature of the third aspect of the invention, the longer the combustion duration of the burner is and the larger the integrated value of the fuel supply amount to the burner is, the longer the post-purge time is. The gas,
Since it can be discharged to the outside of the room, it is possible to further improve safety.

[0013]

Embodiments will be described below with reference to the drawings. Figure 1
FIG. 1 shows a hot water supply device which is an example of a combustion device according to the present invention. This water heater comprises a water heater A, a control unit H that controls the operation of the water heater A, and an operation unit R. The water heater A is connected to the combustion chamber 1, a burner 2 provided inside the combustion chamber 1, a heat exchanger 3 for heating water, and an upper part of the combustion chamber 1, and the combustion gas in the burner 2 is discharged. An exhaust passage 5 that discharges to the outside of the room, a fan 4 as a ventilation unit that supplies combustion air to the burner 2 and ventilates the combustion gas in the burner 2 to the outside through the exhaust passage 5, and a heat exchanger 3. A water supply path 6 for supplying heating water to the tank, a hot water supply path 7 for supplying hot water heated in the heat exchanger 3 to a hot water tap (not shown), and a fuel (gas) for the burner 2. The fuel supply path 8 is provided. In the figure, 30 is an igniter for ignition, and 31 is a frame rod for detecting whether or not the burner 2 is ignited.

In the water supply passage 6, the amount of water supplied to the heat exchanger 3 Qi
The water supply amount sensor 9 for detecting the
Hot water temperature sensor 1 for detecting hot water temperature Tx for hot water tap
0 is provided. The fuel supply passage 8 is connected to a gas supply pipe for general households, and the burner 2 is connected to the fuel supply passage 8.
An electromagnetic proportional valve 11 for adjusting the fuel supply amount Ip to the fuel cell and an interrupt valve 12 for interrupting the fuel supply are provided.

The operation unit R is connected to the control unit H by wire or wirelessly, and has an operation switch 13 for instructing start and stop of the operation of the hot water supply apparatus, a temperature setting switch 14 for setting a set target hot water supply temperature Ts, and various types. LE to display information
D lamps 15 and 16 are provided. In addition, LED
The lamp 15 is configured to display whether the hot water supply device is operating, and the LED lamp 16 is configured to display whether an abnormal combustion state has occurred.

The control section H determines that the combustion control means 101 for controlling the combustion operation of the water heater A, the timer means 102 for measuring the combustion duration of the burner, and the combustion duration of the burner 2 have exceeded the set time. After that, the operation lock means 103 for disabling the operation command from the operation portion R and the fuel supply amount integration means 104 for calculating the integrated value of the fuel supply amount to the burner are provided.

When the water supply amount Qi adjusted by the hot water tap and detected by the water supply amount sensor 9 reaches the set water amount, the combustion control means 101 executes the hot water supply operation described below, and when the water supply amount Qi becomes less than the set water amount, Stop hot water supply operation. In the hot water supply operation, basically, the electromagnetic proportional valve 11 is adjusted so that the hot water supply temperature Tx detected by the hot water supply temperature sensor 10 becomes the set target hot water supply temperature Ts, and the fuel supply amount Ip of the burner 2 is adjusted.
Is adjusted to a target amount for the burner 2 to perform normal combustion, and the rotation speed of the fan 4 with respect to the fuel supply amount Ip is
For example, the fan 4 is set to have a target rotation speed F that is determined based on preset characteristics as shown in FIG.
Control the rotation speed of. In the following description, the basic control in this hot water supply operation is called proportional control.

When the combustion of the burner 2 is started, the timing means 102 starts timing from that point, and measures the time until the combustion of the burner 2 is stopped, that is, the supply of fuel is stopped. .

The control operation of the hot water supply apparatus of this embodiment will be described below with reference to the flow chart shown in FIG.
First, when opening of the hot water tap is detected by the water supply amount sensor 9, ignition control of the burner 2 is executed [step 1,
2]. That is, the air blowing (pre-purge) of the fan 4 is started, the spark by the igniter 30 is started, and the electromagnetic proportional valve 11 and the intermittent valve 12 are opened to start the combustion. When the flame rod 31 detects that the transfer of the fire to the burner 2 is completed, the spark by the igniter 30 is stopped. Then, when the ignition control is started in this way, the timing by the timing means 102 is started [step 3], and at the same time, the integrated value in the fuel supply amount integrating means 104 is reset and the integration of the fuel supply amount to the burner is started. [Step 4]. Then, the proportional control as described above is executed [step 5].

Next, based on the timing information by the timing means 102, it is judged whether or not the combustion operation of the burner 2 has continued for a preset time T _LIMIT [for example, about 30 minutes] or more. When the hot water tap is closed before T _LIMIT has elapsed [steps 6 and 7], the fuel supply amount integrated value Ips obtained by the fuel supply amount integrating means 104 at that time and the combustion timed by the time measuring means 102 The duration t is read [step 8].

Then, based on the fuel supply amount integrated value Ips and the combustion continuation time t, the operating time T _{1 according} to the maximum ventilation amount in post-purging performed after the combustion is stopped as described later is changed and set [step 9]. Here, the post-purge operation time T ₁ is changed and set so as to be longer as the time t is longer than the combustion continuation time t, as shown in FIG. 4, for example. Moreover, the larger the integrated fuel supply amount Ips, the larger the degree of change (slope) of the post-purge operation time T ₁ with respect to the combustion duration t, and as a result, the larger the integrated fuel supply amount Ips, the post-purge operation time T 1. ₁ is set to be long.

As described above, the post-purge operation time T ₁ at the maximum air flow rate is changed and set based on the integrated fuel supply amount value Ips and the combustion duration time t. If the burner 2 has a longer combustion duration time t or a larger fuel supply amount integrated value Ips, the amount of the combustion gas that leaks increases. By continuing the post-purge with the wind force for an appropriate time, the leaked combustion gas can be efficiently discharged outside the room. The minimum value T _1MIN of the post-purge operation time T ₁ at the maximum ventilation
In this case, a minimum required time (for example, about 1 minute) is secured so that the combustion gas remaining in the combustion chamber 1 can be effectively exhausted when the burner stops combustion (see FIG. 5).

Next, after the fuel supply to the burner 2 is stopped and the combustion of the burner 2 is stopped, the rotation speed of the fan 4 is set to the maximum rotation speed F _MAX in the maximum ventilation amount operating state, and the set time is set. The post-purge is executed until T _{1 has} elapsed, and then the post-purge is executed until a predetermined time T ₂ that has been set in advance is reached in the minimum ventilation amount operating state in which the rotation speed of the fan 4 is set to the minimum rotation speed F _MIN. [Step 10 to Step 14]. When the set time T ₂ has elapsed, the post purge is stopped [step 15].

Here, the operating time T ₂ at the minimum air flow rate
Is set to about 6 minutes, and the post-purging with the minimum air flow prevents the hot water that is stored in the heat exchanger 3 from being excessively heated by the closing operation of the hot water tap, and prevents the temperature from becoming too high. In addition, by rotating the fan 4 in a state where the blowing noise is low, when the hot water tap is opened again a few minutes after the combustion is stopped, the fan 4 can be quickly started up and driven to a predetermined rotation speed. it can.

In step 6, if the combustion duration time t of the burner 2 exceeds the set time T _LIMIT , it is judged that there is an abnormal state such as forgetting to close the hot water tap, and an abnormality display (LED The lamp 16 is turned on and off, and the operation lock means 103 is operated to disable the command operation by the operation section R [steps 16 and 17]. Then, after the fuel supply to the burner 2 is stopped and the combustion of the burner 2 is stopped, the post-purge is performed until the preset predetermined time T _{3 has} elapsed with the fan 4 set to the maximum rotation speed F _MAX. Execute [Steps 18-20, Step 1
5]. Here, the predetermined time T ₃ is set to a value of at least 5 minutes or more, the combustion gas remaining in the combustion chamber 1 is discharged to the outside, and the combustion gas leaks into the room due to a long-time burner combustion operation. In this case, the leaked combustion gas can be effectively forced out of the room.

[Other Embodiments] (1) In the above embodiment, in the operation of post-purge performed after the combustion is stopped based on the closing operation of the hot water tap, the maximum air flow rate is changed to the minimum air flow rate after the operation time T ₁ elapses. Although the set time T ₂ is performed, the ventilation operation performed after the operation time T _{1 with} the maximum ventilation amount is not limited to the minimum ventilation amount, but an intermediate value ventilation amount that is less than the maximum ventilation amount and greater than the minimum ventilation amount. May be performed in. (2) In the above-described embodiment, the operation time of the post-purge performed after the combustion is stopped based on the closing operation of the hot water tap is the operation time T ₁ based on the maximum ventilation amount and the operation time T based on the minimum ventilation amount.
_{Although each of the 2} is set, as shown in FIG.
The post-purge may be executed only for the operation time T ₁ based on the maximum ventilation amount that is changed and set based on the combustion continuation time and the integrated value of the fuel supply amount. In this case, steps 13 and 14 in the control operation flowchart shown in FIG.
Will be deleted. (3) In the above embodiment, in the setting of changing the post-purge operation time T ₁ based on the maximum air flow rate, the slope of the change characteristic between the combustion continuation time and the post-purge time is changed by the fuel supply amount integrated value Ips. However, as shown in FIG. 7, the post-purge time may be set on the basis of a characteristic obtained by parallel translation while keeping the slope of the change characteristic constant. (4) In the above embodiment, the post-purge time is set longer as the integrated fuel supply amount value Ips is larger. However, the post-purge operation time may be changed and set based only on the combustion duration time. That is, the changing characteristic shown in FIG. 4 or 7 is set in one characteristic line.
The change characteristic is not limited to a straight line and may be set to various curves as long as the post-purge time is set to be longer as the combustion duration is longer, and the water heater is installed. Information of the internal volume of the room may be stored in advance, and the characteristics may be changed based on the information such that the larger the internal volume, the longer the post-purge time. (5) In the above embodiment, the method of stopping the error display and the method of unlocking the operation are not specified, but the opening / closing operation of the hot water tap, the ON / OFF operation switch,
Alternatively, the abnormality display may be stopped or the operation lock may be released by resetting the power supply of the combustion device (the hot water supply device in the above embodiment).

It should be noted that reference numerals are added to the claims to facilitate the comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a block diagram of the overall configuration

FIG. 2 is a flowchart of control operation

FIG. 3 is a graph showing a change characteristic between a fuel supply amount and a target rotation speed.

FIG. 4 is a graph showing change characteristics of combustion time and post-purge operation time.

FIG. 5 is a graph showing changes in fan rotation speed during post-purge.

FIG. 6 is a graph showing changes in fan rotation speed during post-purge according to another embodiment.

FIG. 7 is a graph showing a change characteristic between a combustion time and a post-purge operation time of another embodiment.

[Explanation of symbols]

 2 burner 4 ventilation means 5 exhaust path 101 control means 102 timing means 104 fuel supply amount integration means

Claims (3)

[Claims] 1. A burner (2) is provided with ventilation means (4) for ventilating combustion air and exhausting combustion gas to the outside through an exhaust passage (5), and said burner is accompanied by a command to stop combustion. A control means (101) is provided to stop the combustion of (2) and to perform a post-purge for continuing the operation of the ventilation means (4) for a predetermined time even after the combustion of the burner (2) is stopped. A combustion device provided with a time measuring means (102) for measuring the combustion duration of the burner (2), and the control means (101), based on the time measuring information of the time measuring means (102), A combustion apparatus configured to change and set the time for performing the post-purge so that the combustion duration is longer. 2. The control means (101) executes the post-purge in such a manner that the post-purge is continued for a predetermined time at the maximum ventilation amount and then for a time longer than the predetermined time at a ventilation amount less than the maximum ventilation amount. The combustion apparatus according to claim 1, wherein the maximum ventilation amount continuation time in the post-purge is set to be longer as the combustion continuation time is longer. 3. A fuel supply amount integrating means (104) for determining an integrated value of a fuel supply amount to the burner (2) during a combustion duration of the burner (2) is provided, and the control means (101) is The combustion apparatus according to claim 1 or 2, wherein the larger the integrated value of the fuel supply amount integrating means (104), the longer the time for which the post-purge is executed is set.