JPS63194121A - Combustion apparatus - Google Patents

Abstract

PURPOSE:To obtain a combustion apparatus which always perform stabilized combustion, by controlling voltage to be supplied to an exhaust fan so that the temperature in exhaust gas detected by a temperature detecting element can keep the temperature corresponding to the change in the combustion rate. CONSTITUTION:A proportional control valve 7 controls the gas rate in order to make the outlet temperature in hot-water detected by an outlet hot-water temperature detector 9 equal to a set temperature. The temperature in exhaust gas is detected by a thermistor 11 and the rotation of an exhaust fan 3 is controlled by a controller 13 in order to keep the temperature in exhaust gas proper to the gas rate controlled by the proportional control valve 7. The temperature in exhaust gas in an exhaust gas duct 12 is raised when air pressure is applied to an exhaust port 4 and exhaust resistance is increased while exhaust rate is decreased. The rise of temperature in exhaust gas is detected by the thermistor 11. Receiving a signal from the thermistor 11, the controller 13 controls the supplied voltage to the exhaust fan 3, controlling it by increasing the rotating number of it, so that the temperature in exhaust gas becomes a set temperature. That is, the exhaust rate is kept at the optimum exhaust gas rate even though the exhaust resistance is changed; as a result, stabilized combustion can be obtained all the time.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to controlling the rotation speed of an exhaust fan of a combustion device.

BACKGROUND OF THE INVENTION In recent years, water heaters have become more compact with built-in exhaust fans.

An example of the above-mentioned conventional water heater will be described below with reference to the drawings.

FIG. 2 shows the overall configuration of a conventional water heater.

In Figure 2, 1 is the main panel, 2 is the heat exchanger, 3 is the exhaust fan, 4 is the exhaust port, 5 is the control device, 6 is the original solenoid valve, 7 is the proportional control valve, and 8 is connected to the heat exchanger 2. A water flow switch provided in the water supply circuit 14, 9 a hot water temperature detector provided in the hot water supply circuit 15 connected to the heat exchanger 2, and 10 a rotation speed detector of the exhaust fan.

When water flows through the water supply circuit 14, the water flow switch 8 is turned on, and the control device 5 receives the signal to rotate the exhaust fan 3, open the solenoid valve 6 and the proportional control valve 7, and ignite the main burner 1. Exhaust gas is discharged to the outside of the machine from an exhaust port 4 by an exhaust fan 3. The proportional control valve 7 is controlled by the control device 5 so that the hot water temperature detected by the hot water temperature detector 9 is equal to the set hot water temperature. Further, the exhaust fan 3 is controlled by the control device 5 so that the rotation speed detected by the rotation speed detector 10 becomes the set rotation speed.

Problems to be Solved by the Invention However, in the above configuration, when the special exhaust resistance due to the wind pressure applied to the exhaust port 4 increases, the air volume decreases even if the number of circulations is constant. This has the problem of poor flammability, resulting in incomplete combustion or extinguishing the fire.

In view of the above-mentioned problems, the present invention provides a combustion device that always performs stable combustion.

Means for Solving the Problems In order to solve the above problems, the combustion apparatus of the present invention provides a temperature detection element such as a thermistor for detecting the temperature of combustion exhaust gas in the air passage, and It is equipped with a control device that controls the rotation speed of the exhaust fan according to the temperature.

Operation According to the above-described configuration of the present invention, when the exhaust resistance increases due to wind pressure and the like and the air volume of the exhaust fan decreases, the exhaust temperature increases. A thermistor detects this exhaust temperature and this signal goes into the controller. This control device detects that the exhaust gas temperature has increased, and increases the rotation speed of the exhaust fan so that the exhaust gas temperature returns to the original set temperature, thereby keeping the amount constant. In this way, a constant air volume can be maintained depending on the amount of combustion, and stable combustion can be obtained.

EXAMPLE Hereinafter, a water heater employing an example of the present invention will be described with reference to the drawings. FIG. 1 shows the overall configuration of a water heater according to a first embodiment of the present invention.

In Fig. 1, 1 is a main burner, 2 is a heat exchanger, and 3 is a main burner.
is an exhaust fan, 4 is an exhaust port, 6 is a solenoid valve provided in the gas passage 16 of the main burner 1, 7 is a proportional control valve, 8 is a water flow switch provided in the water supply circuit 14 leading to the heat exchanger 2, 9
11 is a hot water temperature sensor provided in the hot water supply circuit 15 leading to the outlet of the heat exchanger 2, and 11 is provided in the combustion exhaust gas passage section 12.
A thermistor 13 serves as a temperature detection element for detecting the temperature of combustion exhaust gas, and is a control device that controls the exhaust fan 3 and the entire device.

The operation of the water heater configured as described above will be explained. When water flows into the water supply circuit 14, the water flow switch 8 is turned on. Then, the exhaust fan 3 is rotated by the control device 13 receiving the signal from the water flow switch 8, the main solenoid valve 6 and the proportional control valve 7 are opened, and the main burner 1 is ignited.

Then, the exhaust gas passes through the exhaust gas passage section 12 by the exhaust fan 3 and is discharged to the outside of the machine from the exhaust port 4. The proportional control valve 7 adjusts the gas amount so that the hot water temperature detected by the hot water temperature detector 9 becomes equal to the set temperature. A thermistor 11 detects the temperature of the exhaust gas, and a control device 13 controls the rotation of the exhaust fan 3 so that the exhaust temperature is suitable for the amount of gas adjusted by the proportional control valve 7. Here, when wind pressure is applied to the exhaust port 4, exhaust resistance increases, and the exhaust amount decreases, the exhaust gas temperature in the exhaust gas passage section 12 increases. The thermistor 11 detects this rise in exhaust temperature, and based on the signal, the control device 13 controls the voltage supplied to the exhaust fan 3 to increase the rotation speed of the exhaust fan 3 so that the exhaust temperature reaches the set temperature. . In other words, even if the exhaust resistance changes, the displacement can be maintained at the optimum displacement. Therefore, stable combustion can always be obtained.

Effects of the Invention As described above, the present invention provides a temperature detection element that detects the temperature of combustion exhaust gas in the exhaust gas passage, and a control device that controls the rotation speed of the exhaust fan based on the temperature detected by the temperature detection element. Since the exhaust fan can send a large amount of air, it has the following effects.

■ Stable combustion is always achieved even when exhaust resistance changes due to wind.

(2) Since the air volume suitable for the gas amount can always be obtained, there is no need to consider deterioration of combustibility due to changes in the air volume, and the air volume, which is generally set too high, can be suppressed and thermal efficiency can be increased.

(3) When the amount of exhaust gas was small, the pressure passing through the exhaust port decreased and the exhaust gas could not be discharged due to the wind pressure and the fire was extinguished.
Since the air volume suitable for the amount of gas is always obtained, the amount of gas to the burner can be further adjusted (narrowed down) than before.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a water heater employing an embodiment of the combustion device of the present invention, and FIG. 2 is an overall configuration diagram of a conventional water heater. 3...Exhaust fan, 7...Proportional control valve, 11...Temperature detection element, 13...Control device. Name of agent: Patent attorney Toshio Nakao and 1 other person3-
-1)=Ki Fan 11-"Wa-MissGl?-I think about it, paper power is lacking]Adjustment

Claims (1)

[Claims] an exhaust fan that exhausts combustion exhaust gas; a temperature detection element that is installed in the exhaust gas passage and detects the temperature of the combustion exhaust gas;
A combustion apparatus comprising: a control device that controls a voltage supplied to the exhaust fan so as to maintain the exhaust gas temperature detected by the temperature detection element at a temperature corresponding to the amount of combustion.