JP3023190B2 - Combustion control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion control device for controlling a fuel supply amount of a combustion device in a water heater or the like.

[0002]

2. Description of the Related Art In a forced blast type combustion device used for a water heater or the like, it is difficult to ignite if there is little fuel at the time of ignition, and
Since a large amount of fuel is dangerous, an amount of fuel set for slow ignition is supplied by the proportional valve regardless of, for example, the setting state of the water temperature setting means for setting the combustion amount.

[0003] Such a moderate ignition amount is usually performed by applying a constant current value to the proportional valve. However, there is a manufacturing error in each water heater, and even if a constant current value is applied to the proportional valve, the moderate ignition gas amount is reduced. Is not always constant.

In order to solve such a problem, Japanese Patent Publication No. 2-48811 discloses a proportional valve provided in a fuel supply passage for supplying fuel to a burner and supplying fuel to the burner in proportion to the amount of electricity supplied. Setting means for setting the gas supply amount to the burner by the proportional valve, and adjusting means for adjusting the current value to the proportional valve, by adjusting the current supplied to the proportional valve by the adjusting means, A combustion control device comprising: a control unit that controls the energization of the proportional valve according to a setting state of the setting unit during steady combustion of the burner and supplies an amount of gas to the burner according to the setting state of the setting unit. The control means controls the predetermined voltage determined at a predetermined rate based on the maximum current value to the proportional valve adjusted by the adjustment means regardless of the setting state of the setting means at the time of ignition of the burner. Combustion control apparatus characterized by energizing the proportioning valve the value as slow ignition current has been proposed.

[0005] Further, by such a combustion control device, a predetermined current value determined at a predetermined ratio based on the maximum current value of the current value adjusted by the adjusting means is supplied to the proportional valve at the time of ignition. At this time, the current value used as the basis for determining the predetermined current value is a current value adjusted for each combustor by the adjusting means so that an amount of gas corresponding to the setting state of the setting means can be supplied to the burner. Value. Therefore, even if the proportional valve current for supplying the maximum supply amount set by the setting means is different for each combustor, the amount of gas supplied to the burner is the same for all combustors. For this reason, if the mild ignition current is determined based on the adjusted current value for obtaining the maximum supply amount, the amount of gas supplied to the burner by each combustor does not differ, and a fixed amount of gas is supplied. Slow ignition gas can be supplied.

[0006]

However, such a conventional combustion control device still has the following problems.

That is, as shown in FIG. 4, the combustion control method adopted by the above-described combustion control device is as follows: K = Ia / Ma = Ib / Mb (where Ma and Mb are burners for each of the water heaters C and D). The maximum current value for obtaining the maximum gas supply amount to be supplied to the fuel cell, Ia and Ib are moderate ignition current values, I is a moderate ignition supply amount, and K is a constant. It is determined that the same amount of mild ignition supply is obtained in any water heater.

However, such a combustion control method focuses only on the error of the maximum current value for obtaining the maximum gas supply amount, and does not consider the error of the minimum current value for obtaining the minimum gas supply amount. In other words, although FIG. 4 shows that the proportional valve current and the characteristic curve C of the gas supply amount of each of the hot water heaters C and D both converge to the zero point, in reality, most of the hot water heaters In general, the characteristic curve of the proportional valve current and the gas supply amount does not converge to the zero point as shown in FIG. Therefore, as in the conventional combustion control device described above, when calculating the mild ignition current values Ia and Ib, simply multiplying the maximum current values Ma and Mb to obtain the maximum gas supply amount by the constant K, The slow ignition current values Ia and Ib required to obtain a desired slow ignition gas amount cannot be obtained accurately.

An object of the present invention is to provide a combustion control device which can solve the above-mentioned problems.

[0010]

According to the present invention, a semi-fixed resistor is connected to a proportional valve current control unit, and the current value at the time of minimum combustion and the current value at the time of maximum combustion which are supplied to the proportional valve by the semi-fixed resistor. the combustion control device for adjusting the current value, so that a predetermined slow ignition gas amount Q _S is supplied to the ignition, slow ignition current I
_s is the current value during minimum combustion I _min and the current value during maximum combustion
From I _max, in which calculated based on the following equation, according to the combustion control apparatus characterized by energizing the proportional valve.

[0011]

(Equation 2)

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 1 shows the overall configuration of a water heater A equipped with a combustion control device according to the present invention.

The water heater A comprises a combustion gas supply passage P-1 and a heat exchange passage P-2.

The combustion gas supply path P-1 is connected to the gas supply pipe 12 and
Main solenoid valve 13 and main solenoid valve 1 installed in sequence on the gas supply pipe 12
4, comprising a switching valve 11 and a proportional valve 15, a plurality of burners 17 disposed in a combustion chamber 16, an air supply fan 18, an igniter 19, and a frame rod 20.

On the other hand, the heat exchange passage P-2 includes a water supply pipe 21, a heat exchanger 22, a hot water supply pipe 23, a flow rate sensor 24 attached to the water supply pipe 21, and a water quantity valve 25 attached to the hot water supply pipe 23. And a temperature sensor 26.

FIG. 2 shows a combustion control device B, which comprises a microprocessor MPU, input / output interfaces 31, 32, and a memory m comprising a ROM and a RAM.

In the above configuration, the input interface 31 includes the flow sensor 24, the temperature sensor 26, the main controller 33, the sub controller 34, the frame rod
20 mag is connected.

On the other hand, the output interface 32 includes a main solenoid valve 13, a main solenoid valve 14, a proportional valve 15, and an air supply fan 18.
, The igniter 19 and the water amount valve 25 are connected.

The output interface 32 and the proportional valve 15
A proportional valve drive circuit 35 is interposed between the two, and a semi-fixed resistor 36 (having a maximum current value and a minimum current value) is connected to the proportional valve drive circuit 35.

The above-mentioned various sensors are stored in the memory m.
Based on output signals of 24, 26, etc. and drive signals from controllers 33, 34, the original solenoid valve 13, main solenoid valve 14, switching valve
11, programs for driving the proportional valve 15, the air supply fan 18, the water amount valve 25, and the like are stored.

Then, the hot water supply operation in the normal state by the water heater A having the above configuration is performed as follows.

As shown in FIG. 1, gas is supplied to a gas ejection nozzle 17 through a gas supply passage P-1 and an igniter is provided.
When ignited in 19, the heat of combustion of the gas causes the heat exchange flow path P-
The water flowing inside 2 becomes hot water, and the hot water is supplied to a desired hot water outlet through the hot water supply pipe 23.

According to the present invention, by using the combustion control device B having the above configuration and operation, before the hot water heater A is used, the semi-fixed resistor 36 is used, and the gas amount at the time of minimum combustion and maximum combustion of the hot water heater A is used. After the respective proportional valve currents are adjusted so as to be a predetermined value, the slow ignition current is adjusted to a current value at the time of maximum combustion and a current value at the time of minimum combustion so that a predetermined moderate ignition gas amount is supplied at the time of ignition. The current value is supplied to the proportional valve 15 at the time of ignition.

Hereinafter, the control method will be specifically described with reference to FIG. In FIG. 3, the horizontal axis indicates the proportional valve current, and the vertical axis indicates the gas amount.

As shown in the figure, each of the hot water heaters a and b has a current value I _max-1, I _max-2 which is supplied to the proportional valve 15 in order to obtain the maximum gas amount Q _max due to a manufacturing error. Current value to be supplied to proportional valve 15 to obtain minimum gas volume Q _min I
_{Since min-1 and} I _min-2 are different from each other, these current values are adjusted.

Next, based on the following equation (1) (2), respectively, each water heater in order to obtain a predetermined slow ignition gas amount Q _S a,
The slow ignition current values _{Is-1 and Is-2} to be energized to the proportional valve 15 of b are obtained.

[0028]

(Equation 3)

Thus, in the above equations (1) and (2), (Q _S-
Since _Qmin ) / ( _{Qmax- Qmin} ) = C (constant), the mild ignition current values Is _{-1 and} Is _-2 can be easily calculated.

Then, the semi-fixed resistor 36 connected to the proportional valve drive circuit 35 is operated to store the mild ignition current values _{Is-1 and Is-2} in the memory m. _s-1, I _s-2
The by energizing a proportional valve 15 can be supplied to the proportional valve 15 to a predetermined slow ignition gas amount Q _S.

[0031]

As described above, according to the present invention, the slow ignition current value for obtaining a desired slow ignition gas amount in consideration of not only the current value at the time of maximum combustion but also the current value at the time of minimum combustion. Since the value can be calculated and the proportional valve can be energized, the slow ignition current value can be determined more accurately, and thus, regardless of the production error of the water heater, the amount of the slow ignition gas can be reliably kept constant. can do.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a water heater provided with a combustion control device according to the present invention.

FIG. 2 is a control block diagram of a combustion control device according to the present invention.

FIG. 3 is a characteristic diagram of a proportional valve current and a gas supply amount for explaining the present invention.

FIG. 4 is a characteristic diagram of a proportional valve current and a gas supply amount in a conventional combustion control device.

[Explanation of symbols]

 A Water heater 15 Proportional valve 35 Proportional valve drive circuit 36 Semi-fixed resistor

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroki Maruyama 431-1 Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo Prefecture Inside Nippon Yupro Co., Ltd. Inside Nippon Yupro Co., Ltd. (72) Inventor Masahiro Chino 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu-city, Fukuoka Prefecture Totoki Kiki Co., Ltd. (56) References JP-A-1-118020 (JP, A) 55-75128 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23N 1/00

Claims (1)

(57) [Claims] A combustion control device for connecting a semi-fixed resistor to a proportional valve current control section and adjusting a current value at the time of minimum combustion and a current value at the time of maximum combustion to be supplied to the proportional valve by the semi-fixed resistor. in, so that a predetermined slow ignition gas amount Q _S is supplied to the ignition, the slow ignition current I _s, the current value at the minimum combustion
A combustion control device which calculates from I _min and a current value I _max at the time of maximum combustion based on the following formula, and energizes a proportional valve. (Equation 1)