JPH0216140Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a combustion control device for a combustion device such as a kerosene heater, which vaporizes and burns a liquid fuel such as kerosene.

[Prior art]

A combustion device that vaporizes and burns a liquid fuel is
If the fuel and air are mixed well, a combustion state with performance equivalent to that of a conventional gas combustor can be obtained.

However, when changing the thermal power, it is necessary to set the thermal power steplessly in order to make the change smoothly. Each of them must be controlled. Conventionally, burners that generally have a fuel supply device and a combustion air supply device have a damper installed in the combustion air supply device, and the opening degree of this damper is adjusted by electrically or mechanically controlling it. A method was taken. However, due to the characteristics of the damper, it was difficult to set the firepower steplessly, and in the end, the firepower had to be set in stages.

For this reason, the present invention has already been developed as shown in Figure 4.
A thermal power setting device 1 that sets the thermal power of the combustion device by external operation, a combustion motor 5 that supplies air to the combustion device, a rotation speed sensor 6 that detects the rotation speed of the combustion motor 5, and a rotation speed sensor 6 that detects the rotation speed of the combustion motor 5. It includes an error amplifier 3 that detects the difference between the output and the output of the thermal power setting device 1 and amplifies the output of the thermal power setting device 1, and an electromagnetic pump 12 that supplies fuel to the combustion device. The rotation speed of the combustion motor 5 is controlled according to the setting of the thermal power setting device 1, and the electromagnetic pump 12 is controlled according to the rotation speed of the combustion motor 5 according to the output of the rotation speed sensor 6.
He developed a combustion control device that could easily set the thermal power in a stepless manner, and filed an application as Utility Model Application No. 59-7550.

[Problem that the invention attempts to solve]

However, in this device, since the electromagnetic pump 12 is only controlled based on the rotation speed of the combustion motor 5, the amount of combustion air supplied by the combustion motor 5 and the amount of fuel supplied by the electromagnetic pump 12 cannot be accurately controlled. Although it is possible, no consideration is given to characteristics specific to combustion devices, such as variations in the shape and dimensions of air passages, variations in electromagnetic pump characteristics, etc. For this reason, simply controlling the electromagnetic pump based on the rotational speed of the combustion motor leaves the problem that the combustion characteristics (thermal power) vary depending on the combustion device.

The present invention was made in order to solve the above-mentioned problems, and is intended to adjust the inherent variations in the fuel supply device and combustion air supply device of a combustion device having a fuel supply device and a combustion air supply device. The purpose of the present invention is to obtain a combustion device that has a uniform capacity (firepower) and can set the firepower steplessly.

[Means for solving problems]

The present invention includes a thermal power setting device 1 that sets the thermal power of the combustion device by external operation, a combustion motor 5 that supplies air to the combustion device, a rotation speed sensor 6 that detects the rotation speed of the combustion motor 5, and a rotation speed sensor 6 that detects the rotation speed of the combustion motor 5. an error amplifier 3 that detects the difference between the output of the multi-sensor sensor 6 and the output of the thermal power setting device 1 and amplifies the output of the thermal power setting device 1;
and an electromagnetic pump 12 that supplies fuel to the combustion device, and controls the rotation speed of the combustion motor 5 according to the setting of the thermal power setting device by the output of the error amplifier 3, and also controls the rotation speed of the combustion motor 5 according to the setting of the thermal power setting device. The combustion control device is configured to control the electromagnetic pump 12 according to the rotational speed of the combustion motor 5 by the output of the combustion motor 5, which includes a mechanical damper that adjusts the amount of combustion air, a characteristic selector that adjusts the amount of fuel supplied, and the like. The minimum combustion amount is set in advance at the manufacturing stage by adjusting the amount of combustion air using the mechanical damper, and the maximum combustion amount is set in advance by adjusting the fuel supply amount using the characteristic selector. This makes it possible to obtain a combustion device with uniform combustion capacity that can be adjusted steplessly.

〔Example〕

The present invention will be explained below based on examples. First, the control circuit will be explained using the block diagram of FIG. Reference numeral 1 denotes a thermal power setting device, and when the combustion device is set to a certain thermal power by external operation, its output signal is input to the delay circuit 2. The delay circuit 2 includes a fuel supply device such as an electromagnetic pump (hereinafter referred to as electromagnetic pump) and a combustion air supply device when there is a sudden change in the thermal power setting device, for example, when setting the thermal power from large combustion to small combustion. For example, it is provided so that a balance in operation with a combustion motor (hereinafter referred to as combustion motor) can be maintained and a good combustion state can follow changes in the thermal power setting value. The output of the delay circuit 2 is input to the error amplifier 3, and is input to the combustion motor 5 via the motor drive circuit 4 as the rotational speed output of the combustion motor according to the thermal power set by the thermal power setting device.

When the combustion motor 5 is driven at the set rotation speed, the rotation speed of the combustion motor 5 is detected by the rotation speed sensor 6, and the waveform of the output is shaped by the waveform shaping circuit 7. F-V
(conversion circuit) 8. The rotational speed signal converted into a voltage by the F-V conversion circuit 8 is input to the error amplifier 3.

The rotational speed signal input to the error amplifier 3 is compared with the rotational speed signal corresponding to the thermal power set by the thermal power setting device 1, the error is detected and corrected, and the signal is sent to the combustion motor again via the motor drive circuit 4. 5 is input.
As a result, the combustion motor 5 is controlled to be driven at a rotation speed that provides stable combustion.

On the other hand, a part of the output of the rotational speed sensor 6 whose waveform has been shaped by the waveform shaping circuit 7 is inputted to the arithmetic circuit 9, and a characteristic setting device 13 is inputted with the maximum combustion value of the combustion motor in advance, for example. rotation speed of hour
Characteristic values unique to each combustion device, such as the frequency of the electromagnetic pump 12 corresponding to _R2 , are set, and the signal from the characteristic setting device 13 is sent through an analog-to-digital conversion circuit (A-D conversion circuit) 14. input as an analog signal.

In this arithmetic circuit 9. If the output frequency is - ₁ = x- ₁ / R ₂ - R ₁ (R - R ₁ ), ₁ is the frequency of the electromagnetic pump at minimum combustion, and R ₁ is the frequency of the combustion motor at minimum combustion. An execution program is set where _R2 is the rotational speed of the combustion motor at maximum combustion, and R is the rotational speed of the combustion motor, and the rotational speed signal R from the input rotational speed sensor 6 and the characteristics are set. The setting signal x from the setting device 13 is calculated to determine the driving frequency of the electromagnetic pump 12 for obtaining good combustion with respect to the rotational speed of the combustion motor 5.

The output from the arithmetic circuit 9 is sent to the frequency output circuit 10.
The signal is output as a certain frequency and input to the electromagnetic pump 12 via the electromagnetic pump drive circuit 11 to operate the electromagnetic pump 12. As a result, the electromagnetic pump 12 operates in correspondence with the combustion motor 5.

Next, the outline of the combustion device will be explained based on FIG. 2. Reference numeral 21 denotes a blower tube for secondary air, and a large number of air holes 22 are bored around the entire circumference. A vaporizer tube 23 is inserted into the open end of the blower tube 21 with a heat insulating plate 24 interposed therebetween. A preheating heater 25 is fixed to the lower end of the vaporizing tube 23 to form a kerosene evaporating section, and the temperature is detected by a thermistor 26 to maintain it at a predetermined temperature. A burner body 27 is attached to the upper end of the vaporizing cylinder 23, and a diffuser 30 attached to the end of the rotating shaft of a motor 29 is disposed in the gas chamber 28 at the lower center of the interior. 31
is a blower tube, and at its upper end there is a blower tube 21 for secondary air.
is mounted, and the lower end is connected to the oil tank 3 via the mounting base 32.
It is installed on 3. The motor 29 is fixed inside the blow tube 31 .

An air chamber 34 is surrounded by the blow tube 31 and the secondary air blow tube 21. 35 is an air duct, which is formed by the mounting base 32 and the oil tank 33, and has an air outlet 36 provided on the mounting base 32.
It communicates with the air chamber 34 via. Mounting stand 32
An air introduction chamber 37 is connected to the air introduction chamber 37, and this chamber 37 and the air duct 35 communicate with each other via an air inlet 38 provided on the mounting base 32. Air introduction chamber 3
A combustion motor 5 is fixed inside the 7, and the rotation shaft of this motor 5 is connected to the air duct 35.
It extends inward, and a blower fan 39 is attached to the end thereof.

Further, an adjustable damper 40 is provided on the outer peripheral surface of the air introduction chamber 37, and this damper 40
This adjusts fluctuations in the amount of combustion air supplied due to variations in the shape, dimensions, etc. of combustion air passages such as the air duct 35. A mixing cylinder 41 is provided above the vaporizing cylinder 23, and a pressure equalizing cylinder 42 having a large number of small holes is fixed therein.
A burner body 27 having a large number of burner holes 43 is placed thereon. Reference numeral 44 denotes a flame detection rod, which is installed near the flame port 43. Reference numeral 45 denotes an ignition rod which sends an ignition spark between it and the burner body 27 to ignite the vaporized kerosene. Reference numeral 46 denotes an oil feed pipe, the tip of which opens into the kerosene supply tube 47 of the diffuser 30, and the other end connected to the oil tank 33 via an electromagnetic pump (not shown).

This idea has the above-mentioned structure. First, during the manufacturing stage, the variations in the combustion air passages such as air ducts and the variations in the characteristics of the electromagnetic pump are measured for each combustion device, and as shown in Fig. 3, the minimum The damper 40 is adjusted according to the rotational speed of the combustion motor 5 and the characteristics of the electromagnetic pump 12 during combustion, so that the thermal power during minimum combustion is constant. Next, based on the rotational speed of the combustion motor 5 and the characteristics of the electromagnetic pump 12 at the time of maximum combustion, characteristic values are input into the characteristic setting device 13 so that the thermal power at the time of maximum combustion is constant, and the minimum combustion amount of the combustion device is determined. Specify the maximum combustion amount.

Then, when a desired setting value (variable amount) is input to the thermal power setting device 1, an output voltage is obtained. This output voltage is input to an error amplifier 3 via a delay circuit 2.

On the other hand, the rotation speed sensor 6 detects a rotation speed signal of the combustion motor 5, which will be described later, and generates a voltage proportional to the rotation speed of the combustion motor 5 via a waveform shaping circuit and a frequency-voltage (F-V) conversion circuit 8. The level is output to the error amplifier 3.

Then, the error amplifier 3 compares the input from the F-V converter and the input from the delay circuit 2, and selects the combustion motor corresponding to the rotational speed of the combustion motor 5 and the thermal power set in the thermal power setting device 1. Detects the error with the rotation speed of 5 and outputs it. The output of the error amplifier 3 is input to a motor drive circuit 4, and the motor drive current is controlled according to this input to control the rotation speed of the combustion motor 5. Therefore, the combustion motor 5 is automatically controlled in accordance with the thermal power set in the thermal power setting device 1, and the amount of combustion air is adjusted.

In addition, a part of the frequency signal from the waveform shaping circuit 7 is input to the arithmetic circuit 9 and compared with the input signal from the characteristic setting device 13 to determine the frequency signal corresponding to the rotation speed of the combustion motor 5 and the characteristics of the electromagnetic pump 12. The driving frequency of the electromagnetic pump 12 is determined to obtain good combustion.

This determined frequency is determined by the frequency output circuit 10
is sent to the electromagnetic pump drive circuit 11 via the frequency, and the electromagnetic pump 12 is driven at that frequency. Therefore, the discharge flow rate (fuel supply amount) of the electromagnetic pump 12
is automatically controlled in accordance with the rotation speed of the combustion motor 5 and the characteristic value of the electromagnetic pump 12.

[Effect of idea]

According to this invention, by adjusting the position of the damper and inputting the characteristic values of the electromagnetic pump in advance at the manufacturing stage, combustion air can be supplied by setting the thermal power arbitrarily by external operation. The combustion motor that supplies fuel and the electromagnetic pump that supplies fuel operate automatically and the thermal power can be adjusted steplessly within a certain range, making it possible to smoothly change the thermal power and achieve constant volume combustion with no variation in thermal power capacity. the device is obtained,
Moreover, it is an extremely effective idea, as it does not require the troublesome adjustment of dampers as in the past.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the combustion control device of the present invention, FIG. 2 is a schematic diagram of the combustion device of the present invention, and FIG.
The figure is a diagram showing the rotational speed of the combustion motor and the frequency characteristics of the electromagnetic pump, and FIG. 4 is a block diagram of a combustion device that has already been filed by the applicant. In the figure, 1 is a thermal power setting device, 2 is a delay circuit, 3 is an error amplifier, 5 is a combustion motor, 6 is a rotation speed sensor, 9 is an arithmetic circuit, 12 is an electromagnetic pump, 13 is a characteristic setting device, and 40 is a machine It is a type damper.

Claims (1)

[Scope of utility model registration request] A thermal power setting device 1 that sets the thermal power of the combustion device by external operation, a combustion motor 5 that supplies air to the combustion device, a rotation speed sensor 6 that detects the rotation speed of the combustion motor 5, and a rotation speed sensor 6 that detects the rotation speed of the combustion motor 5. It includes an error amplifier 3 that detects the difference between the output and the output of the thermal power setting device 1 and amplifies the output of the thermal power setting device 1, and an electromagnetic pump 12 that supplies fuel to the combustion device. The rotation speed of the combustion motor 5 is controlled according to the setting of the thermal power setting device, and the electromagnetic pump 12 is controlled according to the rotation speed of the combustion motor 5 according to the output of the rotation speed sensor 6. In this combustion control device, a mechanical damper 40 that adjusts the amount of combustion air and a characteristic selector 13 that adjusts the amount of fuel supply are provided, and the minimum combustion amount is determined by adjusting the amount of combustion air with the mechanical damper 40. A combustion control device characterized in that the maximum combustion amount is set in advance at the manufacturing stage by adjusting the fuel supply amount by a characteristic selector 13, and during that time it can be adjusted steplessly by a thermal power setting device 1.