KR930004524B1 - Controller for combustion device - Google Patents

Abstract

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Description

Combustion control device

1 is a block diagram showing the configuration of the present invention.

2 is a schematic configuration diagram of a bypass mixing gas water heater.

3 is a schematic block diagram of a control device.

4 is a block diagram showing the control of the conventional combustion apparatus.

* Explanation of symbols for main parts of the drawings

1: combustion part 2: blower

3: fuel regulator 4: combustion amount control means

5: air-fuel ratio correction means 6: control device

The present invention relates to a control device for controlling a combustion device used for a hot water heater or a heating device.

The control apparatus of the conventional combustion apparatus includes a combustion section 100 for burning fuel as shown in FIG. 4; A blower 200 for supplying combustion air to the combustion unit 100; A fuel regulator 300 for supplying fuel to the combustion unit 100; The amount of fuel supplied from the fuel regulator 3 according to the state of the combustion amount control means 400 and the combustion unit 100 to control the amount of combustion of the combustion unit 100 by controlling the driving amount of the blower 200. The control device 600 is provided with an air-fuel ratio correction means 500 for feedback correction.

At this time, the blower 200 which supplies combustion air to a combustion chamber is equipped with the rotating body with a large mass, and cannot change a rotation speed rapidly.

On the other hand, the fuel regulator (for example, the proportional valve: 300) which supplies fuel to the combustion chamber can easily change the fuel supply amount because the mass of the valve body is small.

Therefore, controlling the blower 200 and the fuel regulator 300 independently or controlling the blower of the fuel regulator at the same time causes an abnormality in the air-fuel ratio because the amount of fuel supplied by the fuel regulator and the air volume of the blower do not match when the fuel amount is changed. I do it.

Therefore, the amount of air blown by the blower is controlled according to the amount of combustion, and the opening degree of the fuel regulator is controlled by the amount of air blower (e.g. rotational speed) and the state of combustion (fuel ratio) of the blower to prevent the occurrence of abnormal air-fuel ratio when the amount of combustion changes A combustion apparatus is devised (Japanese Patent Laid-Open No. 62-252826).

However, if the air-fuel ratio is controlled by the fuel regulator, the amount of fuel supplied changes according to the air-fuel ratio correction.

Therefore, there is a problem that the heat amount determined by the combustion device cannot be obtained from the combustion unit.

An object of the present invention is to provide a control device for a combustion apparatus that can obtain a target calorific value from a combustion section even if the air-fuel ratio is corrected by varying the supply amount of fuel, and as shown in FIG. A combustion unit 1 for burning combustion, a blower 2 for supplying combustion air to the combustion unit 1, a fuel regulator 3 for supplying fuel to the combustion unit 1, and the blower ( The air-fuel ratio correction means is provided with the combustion amount control means 4 which controls the combustion amount by controlling the airflow amount of 2), and feedback-compensates the supply amount of the fuel from the fuel regulator 3 according to the air-fuel ratio in the combustion part 1. Combustion apparatus provided with the control apparatus 6 provided with the means 5 WHEREIN: The combustion amount control means 4 in the said control apparatus 6 is a function of the fuel increase / decrease by the result of the said air-fuel ratio correction means 5. Depending on the amount of change, the amount of combustion, that is, the blower 2 It is a technical means characterized by correcting the amount of blowing air.

At this time, if the combustion state in the combustion part 1 is not combusted within a predetermined air-fuel ratio, the control apparatus 6 changes the supply amount of fuel by the fuel regulator 3 so that combustion may be performed at a predetermined air-fuel ratio.

However, since the amount of combustion is corrected in advance by the correction by the air-fuel ratio correcting means 5, even if the air-fuel ratio correction is performed, the target heat amount can be obtained by the combustion section 1.

The present invention determines the combustion amount by correcting the change amount of the fuel in advance even if the supply amount of the fuel is changed for the air-fuel ratio correction. For this reason, the control apparatus of the present invention can eliminate the drawback of obtaining the required amount of heat by varying the combustion amount by performing the air-fuel ratio correction compared with the conventional example.

Next, an embodiment in which the present invention is applied to a bypass mixing hot water heater will be described with reference to the drawings. 2 is a schematic diagram of a bypass mixing gas water heater, which is composed of a combustion unit 10 for burning fuel, a gas supply pipe 20, a water pipe 30, and a controller 40. have.

Combustion section 10 is composed of a combustion case 12 having the surface-burning butter 11 of ceramic material disposed therein, and a blower 13 for supplying combustion air into the combustion case 12. The combustion air guided in the combustion case 12 by 13 is discharged from an exhaust port not shown as combustion gas after combustion.

The gas supply light distribution 20 supplies gas of fuel to the nozzle 21 which is opened in the inner circumference of the centrifugal fan 14 of the blower 13, and the source solenoid valve 22, the kettle valve ( 23) The proportional valve 24 is formed in order.

The downstream of the proportional valve 24 is branched into two, in which one switching solenoid valve 25 and the other orifice 26 are formed.

In addition, the main solenoid valve 22, the main valve 23 and the switching solenoid valve 25 open and close the gas supply pipe 20 by energizing control. The proportional valve 24 changes the trimming hole ratio according to the energizing amount. The amount of gas supplied to the nozzle 21 is adjusted. The proportional valve 24 and the switching solenoid valve 25 are the raw material regulator of the present invention.

One side of the water pipe 30 is connected to a supply source of water, and the other is connected to a hot water supply port, and heat-exchanges heat generated by gas combustion of the burner 11 and water flowing therein, and heats water passing through the inside. It has a heat exchanger 31 and a bypass channel 32 which bypasses this heat exchanger 31.

The amount of water introduced into the water pipe 30 on the upstream side of the branch of the heat exchanger 31 and the bypass channel 32 even if the water pressure flowing into the heat exchanger 31 and the bypass channel 32 changes. The electric water quantity control device 33 which combines the function of the governor valve which keeps constant, and the function of the quantity control valve which adjusts the quantity of water is provided.

In addition, the bypass channel 32 is provided with a throttle valve 34 capable of regulating the amount of water passing through the bypass channel 32 and opening and closing the bypass channel 32.

In addition, in order to regulate the total amount of water flowing into the drawing ratio heat exchanger 31 and the bypass channel 32 of the electric water quantity control device, the same as the throttle valve 34 or smaller than the throttle valve 34 is installed. It is.

Moreover, the electric quantity control apparatus 33 and the throttle valve 34 drive the valve body which can open and close a channel as a means of adjusting a quantity, and also drive it using a motor.

The control device 40 is composed of a microcomputer 41, a relay circuit 42 and a drive circuit 43 as shown in FIG. 3, and burner in accordance with the output of the controller 44 or various sensors operated by the user. Sparker 45 to ignite 11, the solenoid valve 22, the kettle valve 23, the proportional valve 24, the switching solenoid valve 25, the electric quantity control device 33, the throttle valve ( 34) is energized control.

Various sensors of the control device 40 include a valve rod of a flame rod 46 and a thermocouple 47, an electric water flow control device 33, and a throttle valve 34 for detecting a flame and an air-fuel ratio of the burner 11. Flow rate detection sensor 50 for detecting the air flow of the potentiometer 48, 49, the blower 13 to detect the opening degree in accordance with the rotational speed is introduced into the heat exchanger 31 and the bypass channel 32 The hot water sensor 52 which detects the temperature of water, the heat exchanger 31, and the tapping water temperature sensor 53 which detects the hot water mixed through the bypass channel 32, and the heat exchanger 31 and the bypass channel ( 32 is provided with a quantity detection sensor 54 for detecting the quantity of water flowing in.

The air volume detection sensor 50 further includes a rotating body interlocked with the motor of the blower 13, and generates a pulse signal according to the rotation of the rotating body. The water quantity detection sensor 54 also includes a rotating body that rotates by the flow of water, and generates a pulse signal according to the rotation of the rotating body.

Then, the computer 41 detects the rotational speed of the blower 13 or the rotational speed of the rotating body at the interval of the pulse signal generated by the airflow rate sensor 50 and the water quantity detection sensor 54 to detect the airflow amount and the quantity.

Next, the combustion control and the quantity control by the computer 41 will be briefly described. When the sand flows through the water pipe 30 by operating the operation tool connected to the hot water supply port, it rotates on the rotating body in the water quantity detection sensor 54, and combustion starts.

The amount of combustion after commencement of combustion is determined according to the amount of water obtained by various sensors, the inlet temperature, the hot water passed through the heat exchanger 31, the mixing hot water temperature (hot water temperature), etc., so as to obtain the set temperature set by the controller 44. The blower 13 controls the voltage so that the air volume according to the determined combustion amount can be supplied to the burner 11.

In other words, the combustion amount = the blowing amount of the blower 13.

Then, the proportionality valve 24 and the switching solenoid valve 25 are energized so that the amount of gas corresponding to the rotational speed of the blower 13 and the flame temperature of the burner 11 is obtained.

In addition, the combustion amount is set so that the hot water passing through the heat exchanger 31 is maintained at a temperature (for example, 60 ° C.) or more that is not adhered to the water drain heat exchanger 31 generated by combustion.

The throttle valve 34 is fixed to an appropriate opening degree calculated from the tapping temperature by the amount passed through the inlet temperature set temperature heat exchanger 31.

In addition, the fixation is set such that the flow rate flowing through the bypass channel 32 is twice the flow rate flowing through the heat exchanger 31.

That is, the ratio of the flow resistance between the bypass channel 32 and the heat exchanger 31 is about 2: 1 by the throttle valve 34. In addition, the opening degree of the throttle valve 34 is fixed when the water supply amount is low or when the tapping temperature is lowered, and the throttle valve 34 is energized so that the opening degree calculated according to the tapping amount tapping temperature is applied.

The electric flow rate control device 33 is energized so as not to exceed the maximum flow rate necessary for obtaining the tapping temperature. Next, the control of the combustion amount by the combustion amount control means already programmed in the computer 41 will be described. The combustion amount Q is proportional to the feedforward combustion amount FF, the heat capacity correction combustion amount K, and the air-fuel ratio correction combustion amount T. The sum of the correction combustion amount P and the integral crystal combustion amount I is expressed by the equation Q = FF + K + T + P + I.

At this time, the feed forward combustion amount FF is detected by the difference between the set temperature Ts set by the controller 44 and the intake temperature Ti detected by the intake temperature sensor 51 and the quantity detecting sensor 54. The amount W is calculated and the heat exchange efficiency l / eff of the heat exchanger 31 is calculated.

This is represented by the formula FF = (Ts-Ti) W / eff.

In addition, the heat capacity correction combustion amount (K) is the difference between the set temperature (Ts) set by the controller 44 and the tapping temperature (Tm) detected by the tapping temperature sensor 53 and the degree of use is previously determined according to the heat exchanger (31). The constant (a) is calculated according to the set heat capacity M and the bypass ratio between the heat exchanger 31 and the bypass channel 32.

This is represented by the equation K = a (Ts-Tm) M.

Further, the calculation of the heat capacity correction combustion amount K calculates the virtual temperature Tc of the heat exchanger 31 required to obtain the set temperature Ts set by the controller 44, and the virtual temperature Tc and the hot water temperature. It may calculate from the difference with hot water To, and heat capacity M etc. which were detected by the sensor 52. FIG.

This is represented by the equation K = (Tc-To) M.

And the air-fuel ratio correction combustion amount T which concerns on this invention correct | amends the gas amount which increases and decreases according to air-fuel ratio correction, and inverts the code of the correction combustion amount N by air-fuel ratio correction.

The air-fuel ratio correction means according to the present invention is programmed in the computer 41 together with the combustion amount control means. This is represented by the formula T = -N.

In addition, the calculation of the proportional correction combustion amount P is detected by the difference between the set temperature Ts set by the controller 44 and the hot water 10 detected by the hot water sensor 52 and the quantity detecting sensor 54. The calculated quantity W is calculated from the proportional constant E and the like.

This indicates that P = E (Ts-To) W represents a deviation value, and E = 0.8 is appropriate in this embodiment. The integral crystal combustion amount I is calculated by integrating the difference between the set temperature Ts set by the controller 44 and the hot water To detected by the hot water sensor 52.

This is represented by the formula In = In-1 + bWn (Ts-To). In addition, b x Wn represents an integral constant, In is an integral correction combustion amount to be calculated this time, and In-1 is an integral correction combustion amount calculated last time.

At this time, the deformation amount of the integral correction combustion amount I is proportional to the flow rate Wh, so that the integral correction combustion amount I can be uniformly evaluated by correcting the time delay required for the feedback. The integral crystal combustion amount I may be used as the change ratio, and the integrated value obtained once may be reasonably evaluated to correspond to the change.

According to this embodiment, by adding the air-fuel ratio correction combustion amount F to the feed-forward combustion amount FF, the gas increased or decreased by the air-fuel ratio correction is previously corrected to the combustion amount.

Therefore, even if the gas supply amount is changed by the air-fuel ratio correction, the target heat amount can be obtained by the combustion unit 10. As a result, the tapping temperature set by the user can be supplied to the user while the combustion amount is not changed by the air-fuel ratio control.

In addition, since the combustion amount Q = FF + K + T + P + I, the tapping temperature set by the user can always be stably supplied. Moreover, in order to apply the voltage according to the amount of combustion to a blower, you may calculate the said amount of combustion directly as calculation of a voltage.

That is, the voltage applied to the blower is to calculate the feed forward voltage, the feed forward voltage, the thermal bridge correction voltage, the air-fuel ratio correction voltage, the proportional correction voltage, and the integral correction voltage. Moreover, although the hot water heater provided with a bypass channel was taken as an example, you may apply this invention to a hot water heater which does not have a bypass channel as well as a combustion type heater.

Moreover, although the example which used gas as fuel was shown, you may apply to the combustion apparatus which used liquid fuel, such as kerosene and steam oil.

Claims (1)

A combustion section for burning fuel and a blower for supplying combustion air to the combustion section; A fuel regulator for supplying fuel to the combustion unit; Combustion amount control means for controlling the combustion amount by controlling the airflow amount of the blower, and combustion control device having an air-fuel ratio correction means for feedback correction of the fuel supply amount from the fuel regulator in accordance with the air-fuel ratio in the combustion section. In the apparatus, the combustion amount control means of the control device corrects the amount of change of fuel in advance by the amount of change of fuel increased or decreased by the air-fuel ratio correcting means, and corrects the amount of combustion by the amount of blowing by the blower according to the amount of change. Control device.

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