JPS6064122A - Burning control device - Google Patents

Abstract

PURPOSE:To contrive to supply steadily the hot-water having designated temperature by adequate following for the fluctuation of power source voltage and the changing of power source frequency by a method wherein the number of revolutions of a fan motor supplying a burning air to a burner is controlled based on the deviation between the hot-water supply temperature and the objective temperature, in a burning control device for suitable adjusting of the valve opening degree of a pressure equalizing valve. CONSTITUTION:In a burning control device of a burning apparatus such as a water heater and the like, the burning quantity of a burner is controlled according to the hot-water supply quantity, then the hot-water supply temperature in a heat exchanger is controlled and maintained at the objective temperature. When the number of revolutions of a fan motor 4 is varied due to the fluctuation of a power source voltage, the change of the number of revolutions is detected in a number of revolutions detecting part 311, the deviation between the present number of revolutions (k) and the objective number of revolutions (e) is detected in a number of revolutions deviation detecting part 313, consequently, the number of revolutions of the fan motor 4 is compensated without delaying via a PI calculating part 314 and a phase calculating part 315. Eventually, when the number of revolutions of the fan motor 4 is decreased due to the lowering of the power source voltage, the phase of the fan motor 4 is controlled toward the increasing direction number of revolutions thereof by a feedback group via the number of revolutions detecting part 311, accordingly, the decreasing of number of revolutions due to the lowering of the power source voltage is compensated rapidly.

Description

Detailed Description of the Invention (Field of the Invention) This invention controls the amount of combustion in a burner in a combustion equipment such as a water heater according to the hot water output, thereby controlling the output humidity of a heat exchanger. It relates to a combustion control device that controls and maintains a target temperature, and in particular controls the rotation speed of a fan motor that supplies combustion air to a burner based on the deviation between the hot water outlet temperature of a heat exchanger and the target temperature, thereby controlling the opening of a pressure equalizing valve. The present invention relates to an improvement in a combustion control device that allows the temperature to be adjusted appropriately.

(Prior art and its problems) FIG. 1 is a diagram showing the basic structure of a water heater equipped with a combustion control device to which the present invention is directed. In the figure, a temperature detector 2 is installed on the outlet side of the heat exchanger 1 to detect the outlet temperature IJlt. : A water flow detector 3 for detecting water flow is provided on the Ic water inlet side.

The fan motor 4 supplies combustion air to the burner 5, and the gas supply path of the burner 5 includes a source valve 6 and a gas governor 7 that turn on and off the gas supply, and a gas governor 7 for turning the gas supply on and off. A pressure equalizing valve 8 is provided, which adjusts and operates in proportion to the air pressure of the air being blown.

In addition, the ignition spark is generated in conjunction with the burner 5 at vA.

The flame detector 10 detects whether or not the ignition is normally ignited by the ignition operation. In addition, 1
1 is a wind pressure switch for checking the operation of the fan motor 4.

Each of the above input/output devices is connected to a control circuit 12, and this control circuit 12 includes a degree setting device 13 for setting a target temperature.
is set number.

FIG. 2 is a block diagram showing the configuration of the portion of the control circuit 12 to which the present invention is applied as an operational system diagram for hot water temperature control. As shown in the figure, this control system is composed of a feedback loop. The basic configuration of this control circuit 12 will be explained below along with the basic operation of the control circuit 4.

First, when water flow to the heat exchanger 1 is detected by the water flow detector 3, the main valve 6 is set to Un, and the igniter 9 is turned on.
is activated. At the same time, the fan motor 4 is driven. Then, the feed fil of the fan motor 4 increases toward a predetermined value, and accordingly, the valve opening of the pressure equalizing valve 8 increases in proportion to the air pressure, and combustion in the burner 5 grows toward a predetermined state. .

Increasing temperature of hot water from heat exchanger 1! When detected by the bX temperature detector 2, the control circuit 12 performs the following control operation. First, in the deviation detection unit 121, the wetness detection signal @a from the temperature detector 2 and the day 1 temperature step regulator 13 are detected.
Calculate the deviation C from the humidity signal. Next PID
The controller 122 performs a PAD operation on the deviation C to create a predetermined control ff1d. Next, the target rotation speed calculation unit 123 determines the target rotation speed e of the fan motor 4 based on this rule. Then, the phase calculation unit 124 determines the phase angle Ml of the rotating magnetic field that drives the rotor of the fan motor 4 based on the target rotation speed e, and sets the signal j as a 1-Riga signal to the fan motor drive unit 125. Output signal: Fan motor drive section 125
In this case, a switching element is provided to turn on and off the drive current of the fan motor 4, and this switching element controls the phase of the drive current of the fan motor 4 at a constant angle of J by the trigger signal @j. Ru.

As a result, the rotation speed of the fan motor 4 becomes a predetermined value, and a predetermined air pressure f corresponding to this rotation speed is transmitted to the pressure equalizing valve 8. As a result, the opening degree of the pressure equalizing valve 8 becomes a predetermined value, and the amount of gas supplied to the burner 5 becomes appropriate.

In this way, the hot water temperature can be adjusted to the set temperature.
J II+. The above-described operations are repeated to maintain the outlet temperature at the set temperature 11, and combustion in the burner 5 continues with the predetermined gas m. If there is a change in the set temperature or the amount of hot water dispensed, this is fed back as a change in the hot water temperature, and the hot water temperature is corrected by the hot water temperature control operation.

In other words, combustion III till
The combustion air-fuel ratio in the burner 5 is made appropriate by controlling the rotational speed of the motor 4.

However, as is well known, when the rotational speed of the fan motor 4 changes by 1 degree due to fluctuations in the electric ft voltage, the rotational speed of the fan motor 4 is made to increase by 777 due to changes in the hot water temperature. Therefore, a control delay occurs and it becomes difficult to stably obtain hot water at a predetermined temperature.

Furthermore, since there are two types of power supply frequencies in Japan, it is preferable that this type of combustion control device be of a shared type.

Therefore, in the conventional shared type combustion control device, it was decided to control the rotation speed of the fan motor using a phase angle calculation formula such that the rotation speed of the fan motor is between 501-1z and 601-1z~. was.

However, in this case, since the control gain is different between 501-1z and 601-1z, there are drawbacks such as over/under water temperature control and the risk of hunting. .

(Object of the Invention) The object of the present invention is to provide a combustion υ] control device that can closely follow fluctuations in the power supply voltage or change the power supply frequency and stably supply hot water at a predetermined temperature. -dsu7shiL-
(Structure and Effects of the Invention) In order to achieve the above objects, a combustion control device according to the present invention includes: a temperature detector for detecting the hot water temperature of the heat exchanger;
A standard temperature setting device, a fan motor for supplying combustion air to the burner, etc., a pressure equalizing valve whose valve opening changes depending on the air pressure of the fan motor to adjust the fuel supply m to the burner, and the temperature a rotation speed determining means for determining a target rotation speed of the fan motor based on a deviation between a temperature detection signal of the detector and a temperature signal of the target humidity setting device; and a rotation speed determining means for detecting the rotation speed of the fan motor. a rotation speed detector; a power frequency detector that detects a power frequency; and a drive current for the fan motor based on the target rotation speed, the rotation speed detected by the rotation speed detector, and the detected frequency by the power frequency detector. The present invention is characterized in that it comprises a phase angle determining means for calculating and determining the phase of.

According to this configuration, a change in the rotation speed of the fan motor is immediately fed back and corrected to an appropriate rotation speed. As a result, changes in tapping temperature due to fluctuations in power supply voltage can be quickly suppressed. In addition, since the power supply frequency is detected and this is taken into account in controlling the rotation speed IIJ of the fan motor, power supply efficiency is improved.

Furthermore, even if the fan motor has a ballast of 1, it is possible to obtain good precontrol characteristics.

(Description of Embodiment) FIG. 3 is a block diagram showing an embodiment of the combustion control device according to the present invention as a system diagram of hot water temperature control operation. In addition,
Parts with the same names as those in Figure 2 are given the same symbols (=J and d2
Although the details are omitted, the above-mentioned hot water temperature control operation of the control circuit 12 of the conventional device is performed by a combination of discrete components, whereas the hot water temperature control operation of the tilJ control circuit 31 of the present embodiment device is It is implemented on a microcomputer.

In the figure, the control circuit 3 of this combustion control 911 Rla
1 includes a rotation speed detection section 311 including a detector for detecting the rotation speed of the fan motor 4; A rotation speed deviation detection section 313 which adds a deviation 9 to the rotation speed detected from the detection section 311 and the target rotation speed e from the target rotation speed droplet trunk 123, and a rotation speed deviation detection section 313 which performs a PI calculation based on the rotation speed deviation. The calculation unit 314 and the PI
It basically includes a phase calculation section 315 that calculates the trigger signal j based on the calculation section 314, the frequency detection signal i from the power supply frequency detection section 312, and the frequency detection signal i from the power supply frequency detection section 312.

In the power supply frequency detection section 312 (Jl, fan motor 4
For example, it is detected whether the power frequency applied to the power source is 50 Hz or 601-1 Hz. That is, when a water heater equipped with the combustion control device is connected to a power source, the power frequency at that time is detected and stored.

In such a configuration, when the power supply voltage fluctuates and the rotational speed of the motor 4 changes, this is detected by the rotational speed detection section 311, and the current rotational speed is changed to the target rotational speed e.
The deviation from J3 is detected by the rotational speed deviation detection section 313. As a result, I) I calculation section 314, phase calculation section 315
Through this, the fan motor 4 is quickly corrected to an appropriate rotational speed. In other words, when the power supply voltage decreases and the rotation speed of the fan motor 4 decreases, a feedback loop via the rotation speed detection section 311 causes the fan motor 4 to be phase controlled in the direction of increasing the rotation speed, and the power supply voltage decreases. The decrease in rotational speed caused by this is quickly corrected. Since the power supply frequency information is input to the phase calculation unit 315, the power supply efficiency can be improved.

[Brief explanation of the drawing]

Fig. 1 does not show the basic configuration of a water heater equipped with a combustion control device to which the present invention is applied, and Fig. 2 shows the basic configuration of a control circuit included in the above-mentioned conventional device. FIG. 3 is a block diagram shown as a system diagram of the υJ four-circuit hot water temperature control operation of the combustion control device according to the present invention. 1...Heat exchanger 2...Temperature detector 4...Full motor 5...Burner 8...Pressure equalization valve 13...Target pest setting device 31... - Control circuit 121...Humidity deviation detection section 122...PID calculation section 123...Target rotation speed calculation section 125...Fan; [-9 Drive section 311...Rotation speed detection section 312... ...Power supply frequency detection section 313...Frequency deviation detection section 314...PI extraction section 315...Phase performance section [Applicant: Tateishi Electric Co., Ltd.

Claims (1)

[Claims] (1) A temperature detector that detects the hot water temperature of the heat exchanger, a target temperature setting device, a fan motor that supplies combustion air to the burner, and a valve opening that changes depending on the air pressure of the fan motor, a pressure equalizing valve that adjusts the amount of fuel supplied to the burner; and a rotation that calculates and determines the target rotation speed of the fan molten metal based on the deviation between the temperature detection signal of the temperature sensor and the target moisture signal value of the target temperature setting device. a rotation speed detector for detecting the rotation speed of the fan motor, a power frequency detector for detecting the power frequency, the target rotation speed, the rotation speed detected by the rotation speed detector, and the power frequency detection. and a phase angle determining means for calculating and determining the phase of the drive current of the fan motor based on the detected frequency of the combustion control side L.