Combustion device

Abstract

To provide a combustion device which can remove such a risk that combustion performance is aggravated by deviation of an air quantity due to a difference of power source quality when using a power source besides a commercial power supply.SOLUTION: A combustion device includes a main body 1 which forms an outer frame, a burner part 2 which is arranged within the main body 1 and burns vaporized combustion oil, fans 10, 14 which are arranged within the main body 1, heat-exchange air taken-in from an outer part of the main body 1 with a combustion gas produced by combustion the burner part 2 and supply the air to at least one side of the burner part 2 or an outer part of the main body 1, an AC motor which rotates the fans 10, 14 and is phase-controlled, a temperature setting part 17a which sets a preset temperature, room temperature detection means 18 which detects a room temperature and a control part 20 which controls fire power of the burner part 2 on the basis of a difference between the preset temperature and the detected room temperature. When the control part 20 judges that a power source wave form of an input power source is predetermined quality or less, the control part inhibits combustion and, therefore, operation is not continued in such a state that combustion is not proper.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a combustion device such as an oil fan heater.

Background Art

[0002] The present invention relates to a warm air heater that performs heating by heat-exchanging exhaust gas generated by combustion of fuel such as oil with indoor air.

[0003] Conventionally, in this type of device, air is supplied from the outside of the main body to the combustion part using a fan, and fuel is supplied to the combustion part to be burned. The air taken in from the outside of the main body is heat-exchanged with the combustion gas and discharged to the outside of the main body to heat the room.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when using a power source other than a commercial power source, there is a risk of deterioration in combustion performance due to a deviation in air volume caused by a difference in power quality.

Means for Solving the Problems

[0006] In order to solve the above problems, in claim 1 of the present invention, a main body forming an outer frame, a burner part disposed in the main body for burning vaporized fuel oil, a fan disposed in the main body for heat-exchanging air taken in from the outside of the main body with the burner part or combustion gas generated by combustion of the burner part and supplying it to at least one of the outside of the main body, an AC motor that rotates the fan and is phase-controlled, A temperature setting unit for setting the desired temperature, A room temperature detection means for detecting room temperature, A control unit that controls the flame output of the burner based on the difference between the set temperature and the detected room temperature, The system includes an input power supply connected to the aforementioned AC motor, The aforementioned input power supply is either a commercial power supply or a power supply other than a commercial power supply. The control unit has a determination unit capable of determining the quality of the power waveform of the input power supply, and the control unit determines that the determination unit determines the power waveform of the input power supply The front A key feature is that if it determines that the power source is a modified sine wave other than commercial power, it prohibits combustion.

[0007] To solve the above problems, claim 2 of the present invention provides a zero-cross detection circuit that outputs a zero-cross signal to the control unit when the voltage of the input power supply is within a predetermined zero-cross range, The system includes a zero-cross timing unit that measures the duration of the zero-cross signal, The control unit determines that if the duration of the zero-cross signal measured by the zero-cross timing unit is greater than or equal to a predetermined value, the power supply waveform of the input power supply is Modified sine wave of power supply other than the aforementioned commercial power supply It is characterized by the determination that it is true. [Effects of the Invention]

[0009] According to the present invention, since combustion is not continued when combustion performance deteriorates, it is possible to provide a heating device that can be operated safely. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic cross-sectional view showing a heating device according to one embodiment of the present invention. [Figure 2] This is a schematic block diagram showing the control configuration of the heating system. [Figure 3] This figure shows the commercial power supply waveform and the zero-crossing signal waveform. [Figure 4] This figure shows the power supply waveform and zero-crossing signal waveform of a modified sine wave.

Embodiments of the Invention

[0011] Embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In each figure, common components and similar components are denoted by the same reference numerals, and their duplicate descriptions are omitted as appropriate.

[0012] FIG. 1 is a schematic cross-sectional view showing a heating device 100 according to an embodiment of the present invention. As shown in FIG. 1, the heating device 100 includes a main body 1 forming an outer frame, and a burner unit 2 disposed inside the main body 1 for burning vaporized fuel oil. The burner unit 2 has a vaporizer 3 for vaporizing the fuel oil, and a burner head 4 disposed above the vaporizer 3 and serving as a combustion unit for burning the vaporized fuel oil.

[0013] The vaporizer 3 has a bottomed cylindrical shape. A heater 5 for heating the vaporizer 3 is disposed, for example, by being cast in the side wall portion or the bottom portion of the vaporizer 3. A heat recovery ring 22 for recovering combustion heat to the vaporizer 3 is provided around the burner head 4.

[0014] The heating device 100 further includes an electromagnetic pump 8 for supplying the fuel oil in the fuel tank 7 to the vaporizer 3 through a fuel pipe 6, and a combustion fan 10 for supplying combustion air to the vaporizer 3 through an air passage 9.

[0015] A large number of flame holes 11 are formed in the side wall portion of the burner head 4. An ignition plug 12 as ignition means and a flame detection means 13 are disposed in the vicinity of the outer peripheral surface of the burner head 4. The ignition plug 12 ignites the air-fuel mixture in which the vaporized fuel oil ejected from the flame holes 11 and the combustion air are mixed by high-voltage discharge. The flame detection means 13 detects the presence or absence of a flame and the combustion state and outputs a signal, and is also called a frame rod.

[0016] In addition, inside the main body 1, a convection fan 14 is arranged which exchanges the air taken in from the outside of the main body 1 with the combustion gas generated by the combustion of the burner unit 2 and discharges it to the outside of the main body 1. By the operation of the convection fan 14, the outside air taken in from the air intake 15 provided on the back surface of the main body 1 is heated to become warm air and is blown into the room from the warm air outlet 16 provided on the front surface of the main body 1.

[0017] Figure 2 is a schematic block diagram showing the control configuration of the heating device 100. As shown in Figure 2, the heating device 100 includes an operation unit 17, a room temperature detection means 18, a vaporizer temperature detection means 19, and a control unit 20. The operation unit 17 receives the user's operation. The operation unit 17 has various switches and buttons such as a temperature setting unit 17a, an operation switch 17b, and an eco switch 17c. The temperature setting unit 17a sets a set temperature based on the user's operation. The operation switch 17b instructs the start and stop of the heating operation. The eco switch 17c instructs the start and stop of the energy-saving operation. Further, the room temperature detection means 18 detects the room temperature which is the temperature of the room where the heating device 100 is placed. The vaporizer temperature detection means 19 detects the temperature of the vaporizer 3.

[0018] <000,0097>The control unit 20 includes a CPU (Central Processing Unit) and a memory, and comprehensively controls the operation of the heating device 100. Various controls by the control unit 20 are realized by the CPU reading out a program pre-stored in the storage means 21 into the memory and executing it.

[0019] For example, the control unit 20 controls the firing power of the burner unit 2 based on the difference between the set temperature set in the temperature setting unit 17a and the room temperature detected by the room temperature detection means 18. The firing power is adjusted by changing the fuel supply amount by the electromagnetic pump 8 and the rotation speed of the combustion fan 10. Here, an appropriate supply amount of combustion air corresponding to the fuel supply amount is determined, and in the storage means 21, the fuel supply amount by the electromagnetic pump 8 and the rotation speed of the combustion fan 10 are stored for each level of the firing power.

[0020] The combustion fan 10 and the convection fan 14 are rotated by AC motors that rotate by inputting the AC waveform of the power supply, and the control unit 20 controls the rotation speed of the combustion fan 10 and the convection fan 14 by performing phase control. The control unit 20 includes a zero-cross detection circuit 23 that outputs a zero-cross signal to the control unit 20 when the voltage of the input power supply is within a predetermined zero-cross range, and a zero-cross timing unit 24 that measures the duration of the zero-cross signal.

[0021] Figure 3 shows the power supply waveform and zero-crossing waveform when the heating device 100 is operating on commercial power. When the control unit 20 performs phase control of the combustion fan 10 and the convection fan 14, it calculates a phase control value according to the difference between the target rotational speed and the current rotational speed, and the combustion level. Based on the rising edge of the zero-crossing signal, the control unit 20 starts supplying power to the motor after a predetermined time according to the phase control value, and continues supplying power until the power supply voltage becomes 0V. This makes it possible to control the rotational speed of the combustion fan 10 and the convection fan 14.

[0022] Figure 4 shows the power supply waveform and zero-crossing waveform when the heating device 100 operates with a modified sine wave. The control unit 20 calculates a phase control value according to the difference between the target rotational speed and the current rotational speed and the combustion level when controlling the phase of the combustion fan 10 and the convection fan 14. Based on the rising edge of the zero-crossing signal, the control unit 20 starts supplying power to the motor after a predetermined time according to the phase control value and continues supplying power until the power supply voltage becomes 0V.

[0023] However, if the power supply waveform is a modified sine wave, the power supply will be immediately stopped when the power-on start signal is output at the timing of 0V in the power supply waveform, which may result in a decrease in rotational speed or even complete stoppage, making it impossible to obtain the desired rotational speed. Furthermore, even if the power-on start signal is output at a timing other than 0V in the power supply waveform, a different voltage may be input compared to the voltage used when operating with commercial power, which may result in an increase or decrease in rotational speed, making it impossible to obtain the desired rotational speed. In addition, if the desired rotational speeds for the combustion fan 10 and the convection fan 14 cannot be obtained, a deviation in the air-fuel ratio may occur, potentially leading to incomplete combustion or misfires.

[0024] Next, we will explain how to determine the quality of the AC waveform of the input power supply in this embodiment. If the power supply used for the heating device 100 is a commercial power supply, a sine wave is input, and the control unit 20 has a zero-cross detection circuit 23 that outputs a zero-cross signal when the input power supply voltage is within a predetermined zero-cross range. The duration of the Hi side of the signal measured by the zero-cross timing unit 24, which measures the duration of the zero-cross signal output from the zero-cross detection circuit 23, will be shorter than the predetermined time. Next, if the power supply used for the heating device 100 is a modified sine wave power supply, the control unit 20 has a zero-cross detection circuit 23 that outputs a zero-cross signal when the modified sine wave is input, and the input power supply voltage is within a predetermined zero-cross range. The duration of the Hi side of the signal measured by the zero-cross timing unit 24, which measures the duration of the zero-cross signal output from the zero-cross detection circuit 23, will be longer than the predetermined time.

[0025] The duration of the Hi side of the zero-cross signal measured by the zero-cross timing unit 24 varies depending on the type of power supply waveform. Using this, the determination unit 26 in the control unit 20 estimates the power supply waveform to be the commercial power supply waveform shown in Figure 3 if the duration of the zero-cross signal from the zero-cross timing unit 24 is shorter than a predetermined time. If the determination unit 26 estimates the power supply used for the heating device 100 to be the commercial power supply waveform, the control unit 20 continues the operation of the heating device 100. On the other hand, if the duration of the zero-cross signal from the zero-cross timing unit 24 is longer than a predetermined time, the determination unit 26 estimates the power supply waveform to be a modified sine wave, for example, as shown in Figure 4. If the determination unit 26 estimates the power supply used for the heating device 100 to be a modified sine wave waveform, the control unit 20 stops the operation of the heating device 100. In this case, the control unit 20 notifies the user of the inoperable state through a display, sound, or other means.

[0026] As a result, the control unit 20 stops operation when it determines that the power supply used for the heating device 100 is a modified sine wave power supply that cannot provide the desired rotational speeds for the combustion fan 10 and the convection fan 14. This prevents deviations in the air-fuel ratio, which could lead to incomplete combustion or misfires.

[0027] Furthermore, the control unit 20 uses a zero-crossing circuit, which is commonly implemented when an AC motor with phase control is equipped, to determine the quality of the AC waveform, thus enabling low-cost quality determination.

[0028] Furthermore, in the embodiment described above, the heating device 100 was described as using a zero-cross detection circuit 23 and a zero-cross timing unit 24 to estimate the commercial power supply and the modified sine wave power supply. However, the heating device 100 may also have a power supply voltage detection means for detecting the voltage of the power supply and a timing means for timing the time during which the fluctuation range of the power supply voltage value remains below a predetermined value. The operation of the heating device 100 may be stopped if the motor, whose phase control is performed according to the duration measured by the timing means, cannot obtain the desired rotational speed. [Explanation of symbols]

[0029] 1 Main unit 2 Burner section 10 Combustion Fan 14 Convection fan 17a Temperature setting section 18. Room temperature detection means 20 Control Unit 26 Judgment Department

Claims

1. The main body forms the outer frame, The main body is located and includes a burner section for burning vaporized fuel oil, A fan is located inside the main body and supplies air taken in from outside the main body to at least one of the burner section or the outside of the main body, after exchanging heat with the combustion gas produced by the combustion of the burner section. The aforementioned fan is rotated by an AC motor with phase control, A temperature setting unit for setting the desired temperature, A room temperature detection means for detecting room temperature, A control unit that controls the flame output of the burner based on the difference between the set temperature and the detected room temperature, The system includes an input power supply connected to the aforementioned AC motor, The aforementioned input power supply is either a commercial power supply or a power supply other than a commercial power supply. The combustion apparatus is characterized in that the control unit has a determination unit capable of determining the quality of the power waveform of the input power supply, and the control unit prohibits combustion if the determination unit determines that the power waveform of the input power supply is a modified sine wave of a power supply other than the commercial power supply.

2. A zero-cross detection circuit that outputs a zero-cross signal to the control unit when the voltage of the input power supply is within a predetermined zero-cross range, The system includes a zero-cross timing unit that measures the duration of the zero-cross signal, The combustion apparatus according to claim 1, characterized in that the control unit determines, when the determination unit determines that the duration of the zero-cross signal measured by the zero-cross timing unit is greater than or equal to a predetermined value, that the power waveform of the input power supply is a modified sine wave of a power supply other than the commercial power supply.

Images