JPH07233937A - Combustion equipment - Google Patents

Abstract

PURPOSE:To prevent incomplete combustion by a method wherein the opening of a proportional valve is controlled in accordance with a set state of the amount of combustion, the number of revolutions of a fan is controlled in accordance with the opening of the proportional valve so that a prescribed air-fuel ratio be obtained, an actual quantity of blown air is computed from an output of a fan power detecting device and the number of revolutions of the fan is corrected so that the prescribed air-fuel ratio be obtained. CONSTITUTION:In order to obtain a set temperature of hot water, a combustion amount control device 6 regulates a flow rate of fuel by controlling the opening of a proportional valve 3 on the basis of a signal from a hot water temperature detecting device 8 and controls combustion of a burner 1 by controlling a fan 4 through a fan revolution number control means 5 so that the number of revolutions in accordance with the opening of the proportional valve be obtained. A fan revolution number correcting means 10 is connected to the fan revolution number control means 5 wherein air-fuel ratio data, i.e., data on the number of revolutions of the fan in relation to the opening of the proportional valve, at the time of a normal state are stored. The fan revolution number correcting means 10 stores data on a power value of the fan in relation to the opening of the proportional valve 2 and corrects the number of revolutions of the fan according to an output of a fan power detecting device 9 and an output of a proportional valve control means 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion apparatus provided with a proportional valve for controlling fuel supplied to a burner and a fan for supplying combustion air to the burner.

[0002]

2. Description of the Related Art A conventional combustion apparatus will be described by taking a gas water heater as an example. FIG. 5 is a schematic view of a conventional water heater, in which a burner 1 for burning fuel is connected with a proportional valve 2 for supplying fuel, and the proportional valve 2 is electrically connected with a proportional valve control means 3. . A fan 4 for supplying air required for combustion is attached to the burner 1, and the fan 4 is electrically connected to a fan rotation speed control means 5. Burner 1
A heat exchanger 7 is attached to the upper part of the. A hot water temperature detecting device 8 is provided in the hot water outlet pipe of the heat exchanger 7. The hot water temperature detecting device 8 is connected to the combustion amount control means 6, and the combustion amount control means 6 is electrically connected to the proportional valve control means 3 and the fan rotation speed control means 5. The data of the relational expression between the opening of the proportional valve 2 and the fan speed is input to the fan speed control means 5 as data for obtaining an ideal air-fuel ratio.

The operation of the conventional combustion device will be described with reference to FIG. The fuel flow rate is adjusted by controlling the opening of the proportional valve 2 through the proportional valve control unit 3 so that the combustion amount set by the user in the combustion amount control unit 6 (hot water temperature in the case of a water heater) is achieved. Further, in order to supply the amount of air that matches the fuel flow rate, the fan rotation speed control means 5 controls the fan 4 so that the fan rotation speed matches the proportional valve opening degree based on the air-fuel ratio data input in advance. As a result, the combustion of the burner 1 was proportionally controlled.

[0004]

However, in the above-mentioned conventional configuration, as a means for obtaining the optimum air-fuel ratio, the fan rotation speed control means 5 is previously stored with the data of the fan rotation speed corresponding to the proportional valve opening, and the fan is rotated. Since the air amount was adjusted by controlling the rotation speed, the air supply port 11 and the exhaust port 12
If the exhaust gas or air supply is obstructed for some reason, such as dust clogging, the actual air amount will decrease even at the specified fan speed that matches the proportional valve opening. Is not obtained and incomplete combustion occurs. As described above, the conventional combustion device has a problem that incomplete combustion cannot be prevented when the supply and exhaust are blocked.

The present invention solves the above-mentioned problems by adjusting the fan rotation speed so that when the supply / exhaust is obstructed, the predetermined fan rotation speed is corrected to obtain the actually required air amount. The purpose is to obtain an optimum air-fuel ratio and prevent incomplete combustion.

[0006]

In order to achieve the above object, the present invention provides a burner and a proportional valve for controlling fuel sent to the burner, a fan for supplying air necessary for combustion, and an electric power flowing to a fan motor. A fan power detection device for detecting,
Proportional valve control means for controlling the opening of the proportional valve according to the setting state of the combustion amount, and controlling the rotation speed of the fan so that the air-fuel ratio is set according to the opening of the proportional valve. A fan rotation speed control device and a fan rotation speed correction means for calculating an actual blown air amount from the output of the fan power detection means and correcting the fan rotation speed so that the set air-fuel ratio is obtained.

[0007]

According to the present invention, when the supply of the air required for combustion in the combustion device is hindered by the above-described configuration, the incomplete combustion is performed by correcting the preset fan rotation speed so as to obtain an ideal air-fuel ratio. Can be prevented.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A water heater according to an embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, a burner 1 for burning fuel
A heat exchanger 7 that transfers the heat of the combustion gas to water is attached to the upper part of the water, and a hot water temperature detecting device 8 is attached to the hot water outlet side of the heat exchanger 7, and the hot water temperature detecting device 8 is a combustion amount control means 6 Connected with. A proportional valve 2 for supplying fuel to the burner 1 is attached, and the proportional valve 2 is electrically connected to the proportional valve control means 3. A fan 4 for supplying air necessary for combustion is attached to the burner 1, and a fan rotation speed control means 5 and a fan power detection device 9 are electrically connected to the fan 4. The combustion amount control means 6 is electrically connected to the proportional valve control means 3 and the fan rotation speed control means 5, and the fan rotation speed control means 5 has a normal air-fuel ratio data, that is, a fan with respect to the opening of the proportional valve 2. Rotation speed data is stored. The fan rotation speed correction means 10 is connected to the fan rotation speed control means 5, and the fan rotation speed correction means 10 stores the data of the fan power value with respect to the opening of the proportional valve 2. The fan rotation speed can be corrected by the output and the output of the proportional valve control means 3.

The operation of the above configuration will be described with reference to FIG. 2. Normally, the combustion amount control device 6 controls the opening degree of the proportional valve 3 based on a signal from the hot water temperature detecting device 8 so that the hot water temperature is set by the user. Is controlled by the proportional valve control means 3 to adjust the combustion flow rate, and the combustion of the burner 1 is controlled by controlling the fan 4 through the fan rotation speed control means 5 so that the rotation speed matches the proportional valve opening. .

However, when the air supply / exhaust is obstructed for some reason (for example, when the air supply / exhaust 11 and the exhaust port 12 are blocked by dust or the like, or when the air supply / exhaust is obstructed by wind and rain, etc.), it is shown in FIG. As shown in FIG. 4, the amount of work performed by the fan 4, that is, the amount of air supplied to the burner 1, is smaller when the air supply / exhaust resistance is present (B) than in the normal state (B). However, if there is a supply / exhaust resistance, the work of the fan 4 decreases, and the fan power value decreases accordingly. Here, the fan rotation speed correction means 9 compares the data of the fan power value at the normal time with respect to the current proportional valve opening which is stored in advance and the fan power value output from the actual fan power detection device 8 and stores it. If it is determined that the result of comparison with the data is outside the allowable range, the rotation speed of the fan 4 is increased to obtain a normal air-fuel ratio from point (B) to point (C) as shown in FIG. Correct until the value is within the allowable range. A normal air-fuel ratio can be obtained even when air supply and exhaust are blocked by such an operation.

[0012]

Industrial Applicability As described above, according to the present invention, when air supply and exhaust is blocked by a water heater installed outdoors in strong wind, rain, etc., and the air supply and exhaust port is blocked by dust etc. If it is hindered, it is possible to prevent incomplete combustion by correcting the predetermined fan rotation speed and adjusting the fan rotation speed so as to obtain an actually required air amount to obtain an optimum air-fuel ratio.

FF type, F which can extend the air supply / exhaust pipe
The present invention is effective even in the case of a water heater such as an E type in which the resistance of the supply and exhaust varies depending on the length of the supply and exhaust pipes, and the optimum air-fuel ratio for the resistance by the supply and exhaust pipes of various lengths. Since the fan rotation speed can be corrected to obtain the above, it is possible to prevent incomplete combustion.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a water heater according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the operation of the water heater.

FIG. 3 is a characteristic diagram showing the relationship between the number of rotations of the fan of the water heater and the amount of work (air flow) of the fan

FIG. 4 is a characteristic diagram showing a relationship between fan power and fan work when the number of rotations of the fan of the water heater is constant.

FIG. 5 is a configuration diagram of a conventional water heater.

FIG. 6 is a block diagram showing an operation of the water heater.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 burner 3 proportional valve control means 5 fan speed control means 6 combustion amount control means 9 fan power detection device 10 fan speed correction means

Claims (1)

[Claims] 1. A burner, a proportional valve for controlling fuel sent to the burner, a fan for supplying air necessary for combustion, a fan power detection device for detecting electric power flowing to a fan motor, and a combustion amount setting state. According to the above, proportional valve control means for controlling the opening of the proportional valve, and fan rotation speed control means for controlling the rotation speed of the fan so that the air-fuel ratio is set according to the opening of the proportional valve. And a fan rotation speed correction means for calculating an actual blown air amount from the output of the fan power detection device and correcting the fan rotation speed so that the set air-fuel ratio is achieved.