JPH10267265A - Apparatus and method for controlling air to gas ratio of gas boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve unstable combustion state generated in a district of excess against wind or air wind by decreasing or increasing a driving voltage of a fan supplied to a supply fan driver by a predetermined amount so that spark voltage is maintained in a reference spark voltage range corresponding to a gas amount. SOLUTION: A gas pressure measuring instrument 407 measures pressure in a gas valve 405 and transmits it to a controller 400. Gas consumption amount is decided according to the pressure transmitted to the controller 400 by the relationship between gas pressure and the gas consumption amount. A temperature sensor 409 measures combustion temperature in a combustion chamber, converts it into a spark voltage corresponding to the combustion temperature, and transmits it to the controller 400. The controller 400 compares the gas consumption amount with the voltage, decreases or increases a fan driving voltage by a predetermined amount so that the voltage corresponding to the consumption amount exists within a predetermined reference spark voltage range to decrease or increase a rotational speed of a supply fan 401, thereby regulating an amount of the air supplied to the chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling an air-to-gas ratio of a gas boiler and, more particularly, to an apparatus for controlling the air-to-gas ratio of a gas boiler. The present invention relates to a gas boiler air-to-gas ratio control apparatus and method for controlling pressure.

[0002]

2. Description of the Related Art Recently, gas boilers for indoor heating and hot water supply have been widely used due to their convenience and discharge of low-polluting substances.

FIG. 1 is a schematic diagram schematically showing a configuration of a conventional gas boiler.

As shown in FIG. 1, a conventional gas boiler includes a gas valve 101, a control plate 103, a burner 105, a spark plug 107, an infrared sensor 109, a heat exchanger 111, an air supply hood 113, an air supply fan 115, a flow valve. 11
7, straight water supply pipe 119, circulation pump 121, three-way valve 12
3. Water tank 125, hot water supply pipe 127, hot water return pipe 1
29. The straight water supply pipe 119 is connected to the heat exchanger 111.
It is configured to pass through the inside of.

FIG. 2 is a schematic diagram showing the position of the infrared sensor shown in FIG. As shown in the figure, the infrared sensor 109 is mounted on the combustion chamber case 200 separated from the flame 201 by a certain distance L.

Next, the operation of the conventional gas boiler will be described.

When the gas is supplied to the burner 105 by the opening / closing operation of the gas valve 101, the ignition spark generated by the ignition plug 107 ignites the gas. When the ignition is performed, a combustion spark due to the combustion is generated from the burner 105.
At this time, the infrared sensor 109 senses the temperature of the combustion spark, generates a spark voltage corresponding to the temperature of the combustion spark, and transmits the spark voltage to the controller 103, thereby transmitting information on the ignition and the combustion state of the burner 105 to the controller 103. To communicate.

When the gas is burned by ignition, the high-temperature combustion gas generated at this time rises upward. Above the burner 105 through which the combustion gas passes, a heat exchanger 111 for heating hot water is installed. Hot water circulates inside the heat exchanger 111. Further, the straight water (cold water) passing through the straight water supply pipe 119 is heated in the heat exchanger 111. Therefore, hot water and straight water (cold water) are generated by combustion in the burner 105.
Is heated.

The three-way valve 123 is controlled to circulate hot water in the heating mode and to supply hot water in the hot water mode. Here, in the recognition of the hot water mode, when supplying the straight water to use the hot water, the hot water use state is determined by recognizing the straight water supplied to the flow valve 117.

When the operation mode of the conventional gas boiler is the heating mode, the hot water heated in the heat exchanger 111 is discharged through a hot water supply pipe 127 to a hot water pipe (not shown) installed in the room. After that, it returns through the hot water return pipe 129 again. The hot water returned through the hot water return pipe 129 is deprived of heat while passing through a hot water pipe (not shown), so that the temperature of the water tank 12 is lower than when discharged from the heat exchanger 111.
Return to 5. The hot water returned to the water tank 125 is a three-way valve 123
Then, it passes through the circulation pump 121 and flows into the heat exchanger 111 again. The inflowing hot water is heated again by the heat exchanger 111 and then discharged through the hot water supply pipe 127.

The three-way valve 123 is for controlling the flow path. In the heating mode, the three-way valve 123 is supplied from the water tank 125 to the heat exchanger 111.
In the hot water mode, the heat exchanger 111 is controlled so as to circulate through a closed circuit including the three-way valve 123, the circulation pump 121, and the heat exchanger 111. Therefore, the straight water flowing into the heat exchanger 111 via the straight water supply pipe 119 is discharged after being heated to high-temperature hot water by heat exchange with the hot water.

A conventional gas boiler having such a configuration and operation may cause incomplete combustion or peroxygen combustion due to an external influence during combustion, that is, a forward wind or a backward wind. In addition, there is a problem that the gas boiler may extinguish if the forward wind or the reverse wind is excessive. Therefore, in regions where excessive wind or headwinds occur, ignition and fire-extinguishing are repeated so that the life of the boiler is shortened, and the heating function of the gas boiler is not sufficiently performed.

[0013]

SUMMARY OF THE INVENTION The present invention is to solve such a conventional problem, and its object is to
An object of the present invention is to provide an apparatus for controlling an air-to-gas ratio of a gas boiler for improving an unstable combustion state that occurs in an area where excessive headwind or excessive wind occurs.

[0014]

In order to achieve the above object, an air-to-gas ratio control device for a gas boiler according to the present invention comprises a supply fan drive for driving a supply fan, and a pressure in a gas valve. A gas amount measuring device that measures the gas amount by measuring, a temperature sensor that measures the combustion temperature in the combustion chamber and converts the combustion temperature into a spark voltage, and a spark voltage within a reference spark voltage range corresponding to the gas amount. And a controller for decreasing or increasing the fan drive voltage supplied to the air supply fan drive by a predetermined amount so as to be maintained at a predetermined value.

In order to achieve the above object, a method for controlling an air-to-gas ratio of a gas boiler according to the present invention comprises the steps of: setting a fan drive voltage change amount of a fan drive voltage in a gas boiler during combustion; Measuring the amount of gas supplied through, and, if the gas amount is constant, measuring the spark voltage; and, if the spark voltage is greater than the upper limit of the reference spark voltage range corresponding to the gas amount, the gas amount is reduced. Reducing the corresponding fan drive voltage by the fan drive voltage change amount, and increasing the fan drive voltage by the fan drive voltage change amount if the spark voltage is smaller than the lower limit of the reference spark voltage range. The voltage is set to be within the reference spark voltage range.

According to the above-described gas boiler apparatus and method, even if incomplete combustion or peroxygen combustion occurs due to an external influence during combustion, that is, a forward wind or a backward wind, the gas boiler will not be extinguished. Further, the problem of shortening the life of the boiler due to frequent repetition of ignition and extinguishing is also solved. In other words, the air-to-gas ratio is properly adjusted, so that the heating function can be expected to perform smoothly, and as a result,
Combustion efficiency is improved.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 3 is a graph showing a normal combustion region according to the relationship between gas consumption and spark voltage. Here, the spark voltage refers to a voltage converted from the temperature of the flame generated at the time of combustion by the burner. Generally, a voltage corresponding to a change in the color of a flame generated during combustion is generated as a spark voltage.

As shown in FIG. 3, when the spark voltage is detected to be excessive at a predetermined gas consumption, it indicates that the current combustion state is a normal wind state, and when the spark voltage is detected to be too low, the current combustion state is present. Indicates that the combustion state is in a headwind state. Here, the normal wind state refers to a state in which peroxygen combustion is performed by inflow of air much larger than air required for combustion. In addition, the headwind state refers to a state in which incomplete combustion is performed by the burned supply gas flowing back into the gas boiler without being smoothly discharged.

In FIG. 1, a hatched portion indicates a normal combustion region, which is separated into a normal combustion region and a normal wind region with the upper limit spark voltage line Vfmax as a boundary, and the lower limit spark voltage line Vfmax.
It is separated into a normal combustion region and a headwind region with fmin as a boundary.

First, an air-to-gas ratio control device for a gas boiler according to the present invention will be described.

FIG. 4 is a block diagram showing a configuration of an air-to-gas ratio control device for a gas boiler according to the present invention.

As shown in the figure, the air-to-gas ratio control device of the gas boiler includes a controller 400, an air supply fan 401, an air supply fan driving unit 403, a gas valve 405, a gas pressure measuring device 407, a temperature sensor 409, A storage unit 411 is included.

The air supply fan 401 is connected to the air supply fan drive section 40.
3 The air supply fan drive unit 403 includes the controller 40
0, and the air supply fan drive unit 403 is driven according to the variation of the fan drive voltage by the controller 400.

The gas valve 405 is connected to the controller 400. The gas pressure measuring device 407 is connected to the gas valve 405 and measures the gas pressure. In addition, gas pressure measuring device 4
07 is connected to the controller 400 and transmits the measured gas pressure to the controller 400.

The storage unit 411 is connected to the controller, and stores a predetermined storage value according to the need of the controller 400.

A temperature sensor 409 installed in the combustion chamber is connected to the controller 400 and transmits a spark voltage based on the measured combustion temperature to the controller 400. Here, the temperature sensor 409 may be constituted by an infrared sensor.

Next, the operation of the air-to-gas ratio control device for a gas boiler will be described.

The gas pressure measuring device 407 includes a gas valve 405
The internal pressure is measured and transmitted to the controller 400. Controller 4
The pressure transmitted to 00 determines gas consumption according to the relationship between gas pressure and gas consumption.

The temperature sensor 409 measures the combustion temperature in the combustion chamber, converts it into a spark voltage corresponding to the combustion temperature, and transmits it to the controller 400.

The controller 400 compares the gas consumption with the spark voltage and determines the fan drive voltage so that the spark voltage corresponding to the gas consumption exists within the range of the predetermined reference spark voltage shown in FIG. Is decreased / increased by a predetermined amount, and the number of revolutions of the air supply fan is decreased / increased, thereby adjusting the amount of air supplied to the combustion chamber.

At this time, the amount of change in the fan drive voltage is stored in the storage unit 411. Here, the amount of change in the fan drive voltage is set to a predetermined voltage in the range of 5V to 15V. Preferably, it is set to 10V.

The adjustment of the fan drive voltage is repeated until the spark voltage becomes within the normal range.

On the other hand, when the gas consumption is changed, it is readjusted by adding the stored change in the fan drive voltage to the fan drive change voltage corresponding to the changed gas consumption.

Next, a method for controlling the air-to-gas ratio of a gas boiler according to the present invention will be described.

FIG. 5 is a flowchart showing a method for controlling the air-to-gas ratio of a gas boiler according to the present invention. When the boiler is activated, it is necessary to collect basic data to grasp the current combustion state. That is, the gas consumption Gc consumed in the combustion chamber is measured, and the temperature sensor 409
By measuring the combustion temperature in the combustion chamber, the spark voltage Vb corresponding to the current combustion state is measured (step S501). A fan drive voltage Vfd and a reference spark voltage range corresponding to the measured gas consumption are determined. That is, the upper limit spark voltage Vfmax and the lower limit spark voltage Vfm
is determined, and an appropriate voltage change width ΔVfd of the fan drive voltage is selected (step S503). Here, the width of the voltage change amount is set to 10V.

Then, it is checked whether or not the consumption of the gas supplied to the combustion chamber is constant (step S505). Here, the fluctuation state of the gas consumption is determined by sensing a pressure change in the gas valve 405 occurring within a predetermined time. That is, the gas valve 40
The first gas pressure at a predetermined time in 5 is measured, and the second gas pressure is measured after a predetermined time has elapsed. afterwards,
The first gas pressure and the second gas pressure are arithmetically averaged. Here, the predetermined time is set to 1 second to 3 seconds. Preferably, it is set to 2 seconds. The gas consumption Gc is determined by a predetermined gas pressure-gas consumption relationship.

First, the case where the gas consumption is constant will be described. The spark voltage Vb corresponding to the temperature of the combustion spark in the combustion chamber is compared with the upper limit spark voltage Vfmax and the lower limit spark voltage Vfmin (step S507). At this time, three cases can be considered. That is, the spark voltage Vb
Is smaller than the lower limit spark voltage Vfmin, the spark voltage V
b is the lower limit spark voltage Vfmin and the upper limit spark voltage Vfmax
And the case where the spark voltage Vb is higher than the upper limit spark voltage Vfmax.

First, the spark voltage Vb is lower than the lower limit spark voltage Vf.
A case where the value is smaller than min will be described. In this case, it is determined that a headwind is present, and it is necessary to increase the airflow in order to solve this. Such an increase in the air volume is achieved by increasing the fan drive voltage Vfd. That is, the voltage change amount ΔVfd is added to the fan drive voltage (step S511). Then, the added voltage change amount + ΔVfd is stored in the storage unit 411 (step S5).
13). Then, it is checked again whether the gas consumption is constant (step S505), and the subsequent steps are repeated.

Second, the spark voltage Vb is lower than the lower limit spark voltage Vf.
A description will be given of a case where the current value is between the minimum and the upper limit spark voltage Vfmax. This is a normal state. Therefore, it is checked again whether or not the gas consumption is constant (step S505), and the subsequent steps are repeated.

Finally, the spark voltage Vb is equal to the upper limit spark voltage Vf.
A case where the value is larger than max will be described. In this case, it is determined that the wind is in a normal wind state, and it is necessary to reduce the air flow to solve this. Such a decrease in the air volume is achieved by reducing the fan drive voltage Vfd.
The voltage change amount ΔVfd is subtracted from the fan drive voltage (step S521). And the subtracted voltage change amount-ΔVf
d is stored in the storage unit 411 (step S523).
Then, it is checked again whether the gas consumption is constant (step S505), and the subsequent steps are repeated.

Next, a case where the gas consumption is not constant in the step of determining whether or not the gas consumption is constant (step S505) will be described. The case where the gas consumption is not constant during the gas boiler combustion process is the case where the gas boiler is used at a constant gas consumption and the gas consumption is changed by resetting the temperature on the way.

First, the already set fan drive voltage is adjusted to the fan drive change voltage corresponding to the changed gas consumption (step S531). However, the fan drive change voltage is a fixed and invariable fan drive voltage that does not consider the influence of the outside, that is, the influence of a forward wind or a backward wind. Therefore, the fan drive change voltage must be changed to a correction voltage that takes into account external influences. The correction is performed by using the voltage change amount of the fan drive voltage corresponding to the gas consumption amount before the change. That is, the correction is performed by adding the voltage change amount ΔVfd stored in the storage unit 411 to the fan drive change voltage (step S533). If the stored voltage change amount ΔVfd has a positive (+) value, it means that the fan drive voltage increases for normal combustion. The stored voltage change ΔVfd applies equally to the changed gas consumption. Therefore, the changed fan drive voltage is the voltage change amount ΔV
It is determined as a value obtained by adding fd.

However, if the stored voltage change .DELTA.Vfd has a negative (-) value, it means that the fan drive voltage drops for normal combustion. Stored voltage change Δ
Vfd applies equally to the changed gas consumption.
Therefore, the changed fan drive voltage is determined as a value obtained by subtracting the voltage change amount ΔVfd from the fan drive change voltage before the change.

Then, it is checked again whether or not the gas consumption is constant (step S505), and the subsequent steps are repeated.

[0046]

As described above, according to the present invention,
Even if incomplete combustion or peroxygen combustion occurs due to external influences during combustion, such as forward wind or headwind, there is no fear that the gas boiler will extinguish. Further, the problem of shortening the life of the boiler due to frequent repetition of ignition and extinguishing is also solved.
In other words, by properly adjusting the air-to-gas ratio,
The smooth execution of the heating function can be expected, and as a result, the combustion efficiency is improved.

Although the present invention has been described in detail with reference to the preferred embodiments, the present invention is not limited to these embodiments and can be modified and improved without departing from the spirit of the present invention. Of course.

[Brief description of the drawings]

FIG. 1 is a schematic diagram schematically showing a configuration of a conventional gas boiler.

FIG. 2 is a schematic diagram showing a position of the infrared sensor shown in FIG.

FIG. 3 is a graph showing a normal combustion region according to a relationship between gas consumption and spark voltage.

FIG. 4 is a block diagram showing a configuration of an air-to-gas ratio control device for a gas boiler according to the present invention.

FIG. 5 is a flowchart illustrating a method for controlling an air-to-gas ratio of a gas boiler according to the present invention.

[Explanation of symbols]

 400 controller 401 air supply fan 403 air supply fan drive unit 405 gas valve 407 gas pressure measuring device 409 temperature sensor 411 storage unit

Claims (10)

[Claims] In a gas boiler during combustion, a step of setting a fan drive voltage change amount of a fan drive voltage, a step of measuring an amount of gas supplied through a gas valve, and the gas amount is constant. If the spark voltage is higher than the upper limit of the reference spark voltage range corresponding to the gas amount, the fan drive voltage corresponding to the gas amount is reduced by the amount of change in the fan drive voltage, and the spark voltage is reduced. Adjusting the fan drive voltage by the amount of change in the fan drive voltage if the value is smaller than the lower limit of the reference spark voltage range, so that the spark voltage is within the reference spark voltage range. A method for controlling an air-to-gas ratio of a gas boiler. 2. The method of controlling an air-to-gas ratio of a gas boiler, comprising: when the gas amount is not constant, changing the fan drive voltage to a predetermined fan drive change voltage corresponding to the changed gas amount. The method of claim 1, further comprising a changing step. 3. The method of controlling an air-to-gas ratio of a gas boiler, further comprising: storing the fan drive voltage change amount; and adding the fan drive voltage change amount to the fan drive change voltage. The method for controlling an air-to-gas ratio of a gas boiler according to claim 2, characterized in that: 4. The gas amount measuring step includes: measuring a first pressure in the gas valve; measuring a second pressure in the gas valve; and calculating an average pressure from the first pressure and the second pressure. The method of claim 1, further comprising calculating a gas amount corresponding to the average pressure. 5. The method according to claim 1, wherein the measuring the gas amount comprises setting a time interval between the first pressure measurement time and the second pressure measurement time to a predetermined time interval within a range of 1 second to 3 seconds. The method for controlling an air-to-gas ratio of a gas boiler according to claim 4, characterized in that: 6. The spark voltage measuring step includes: measuring a combustion temperature in the combustion chamber using an infrared sensor installed at a predetermined position in a wall of the combustion chamber; and converting the combustion temperature to the spark voltage. The method of claim 1, further comprising the step of: controlling the air-to-gas ratio of the gas boiler. 7. The method according to claim 1, wherein the amount of change in the fan drive voltage is set to a predetermined voltage within a range of 5V to 15V. 8. An air supply fan drive unit for driving an air supply fan, a gas amount measuring device for measuring a gas amount by measuring a pressure in a gas valve, and a combustion temperature for measuring a combustion temperature in a combustion chamber. A temperature sensor for converting to a spark voltage; and a fan drive voltage supplied to the air supply fan drive unit reduced or increased by a predetermined amount such that the spark voltage is maintained within a reference spark voltage range corresponding to the gas amount. An air-to-gas ratio control device for a gas boiler, comprising: 9. The air-to-gas ratio control device for a gas boiler further includes a storage unit for storing a fan drive voltage change amount of the fan drive voltage, wherein the fan drive voltage changes when the gas amount is not constant. 9. The air pair of a gas boiler according to claim 8, wherein the fan drive change voltage is changed to a fan drive change voltage corresponding to the set gas amount, and the fan drive voltage change stored in the storage unit is added to the fan drive change voltage. Gas ratio control device. 10. The apparatus according to claim 8, wherein the temperature sensor is an infrared sensor.