JPS6226415A - Proportional burner - Google Patents

Abstract

PURPOSE:To make it simple to control the maximum and minimum air volumes and prevent lift combustion and back combustion by connecting to a microcomputer two variable resistances which corrects the maximum and minimum rotational speeds of a blower. CONSTITUTION:A proportional burner is provided with an 8-bit microcomputer 14 (hereinafter called micom) which controls the rotational speed of a blower, a variable resistance 15 which corrects the maximum rotational speed of the blower, and a variable resistance 16 which corrects the minimum rotational speed of the blower. A rotational speed of the motor 18 is obtained by the micom 14 in accordance with an input value of a hot water supply thermostat 4, and maximum and minimum rotational speeds are corrected by regulating a variable resistances 15 and 16, and at the same time the rotational speed can be kept from becoming larger than the required maximum rotational speed or smaller than the minimum rotational speed. With this arrangement, required maximum and minimum air volumes can be controlled simply and lift combustion and back combustion can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a proportional combustion device, and particularly to control of the flow rate of combustion air.

[Background of the invention]

In general, a gas combustion device consisting of an air-gas mixing pipe, a zero governor, a primary burner, etc. can control the gas flow rate according to the amount of air supplied by the zero governor, and the amount of air supplied is controlled by the rotation speed of the fan motor, etc. This has the advantage of being able to control the combustion amount, but on the other hand, there is an optimum combustion range, that is, a maximum combustion amount and a minimum combustion amount, and there is a problem that combustion deteriorates if the combustion exceeds these ranges. However, in this oak combustion device, in order to ensure the optimum combustion range, the maximum and minimum rotation speeds of the blower are determined from the required maximum air volume and minimum required air volume. However, even if the rotational speed is kept the same through feedback control, there are drawbacks such as variations in the blower and back combustion in individual parts of the combustion device. Furthermore, in consideration of variations in equipment, the proportional control range had to be set narrowly so as not to fall below the required maximum or minimum air volume.

Note that, for example, Japanese Patent Publication No. 57-28847 is related to this type of combustion device.

[Purpose of the invention]

The purpose of the present invention is to easily control the required minimum air volume to the required maximum JR- even if there are variations in the blower or component equipment, prevent lift combustion or bubble combustion, and widen the proportional control range. An object of the present invention is to provide a proportional combustion device v that can set a wide proportional control range.

[Summary of the invention]

The present invention is equipped with two variable resistors at the input terminals of a microcomputer to correct the maximum rotation speed and minimum rotation speed of the blower, and inputs the values corrected by the variable resistors to the microcomputer, and the reference voltage of the microcomputer is The voltage applied to the blower is corrected based on the value of human power from the variable resistor, and the maximum and minimum rotational speeds of the blower are corrected.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of the proportional fuel control system* applied to a gas hot water heater according to the invention, and FIG. 2 is a control circuit diagram of the blower drive motor in FIG. 1.

In Fig. 1, 1 is a heat exchanger, and hot water supply pipe 2-a
, the heating pipe 2-b is in close contact with the heating pipe 2-b, and the entire outer periphery is provided with cross fins. 3ri is a flow switch for detecting the full flow of water on the hot water supply side; 4 is a hot water supply length disposed at the outlet of the hot water supply pipe 2-a; and 5 is a faucet metal.

6 is a pump that circulates heating hot water, 7 is a heating thermostat,
It is arranged at the outlet of the heating pipe 2-b. 8 is all-
1 is a secondary burner, 9 is a mixing tube that distributes air and gas, 10 is a zero cabana that operates based on the pressure difference generated in the mixing tube 9 according to the amount of air supplied, 11 is a solenoid valve that stops the gas supply, 1
2 is a blower that supplies combustion air, and rotation speed detection s13
is installed inside.

In FIG. 2, 14 is an 8-bit microcomputer (hereinafter referred to as microcomputer) that controls the rotation a of the blower;
15 is a variable resistor provided at the microcomputer 140 input terminal and corrects the maximum rotation speed of the blower; 16rt microcomputer 14;
A variable resistor provided at the 0 input terminal corrects the minimum rotational speed of the blower, an amplifier that amplifies the output voltage from the 17ri microcomputer 14, and 18 a motor for driving the blower that rotates with the amplified voltage from the amplifier 17.

In the hot water heater with the above configuration, when the faucet 5 is opened to perform hot water supply operation, the hot water supply thermo 4 detects the hot water temperature, and if the hot water temperature is higher than the set temperature, the rotation speed of the blower 12 is decreased. As a result, the p air supply amount decreases, the pressure of the zero governor 10 decreases, the gas flow rate also decreases, the combustion amount decreases, and the outlet temperature decreases to the set temperature. When the hot water outlet temperature is lower than the set temperature, the temperature at the foot of the hot water outlet becomes the set temperature by the operation opposite to the above.

Here, the case where the outlet temperature is higher than the set temperature and the combustion amount reaches the required minimum combustion amount, or vice versa, will be explained with reference to FIG.

The microcomputer 14 determines the rotation speed of the motor 18, that is, the rotation speed C of the blower, according to the input value of the hot water thermometer 4. Next, calculate the sum of the input value B from the variable resistor 16 that corrects the minimum rotation speed and the maximum rotation speed reference value A, and compare it with the required rotation speed C determined earlier. When the relationship holds true, the microcomputer 14 outputs the value A + B, and the amplifier 17 applies the voltage ' to the motor 18. When the relationship C≧A+B holds true, the microcomputer 14 outputs the value of C. Therefore, the rotation speed of the blower 12 does not fall below the required number. Furthermore, by adjusting the variable resistor 16, the minimum rotation speed can be corrected. Similarly, the maximum number of rotations can be corrected by adjusting the variable resistor 15, and does not exceed the required maximum number of rotations.

A flow chart of the rotational speed of the blower is shown in FIG. 3.

Therefore, even if there are fluctuations in the blower or variations in component equipment, the required maximum air volume and minimum air volume can be easily controlled, lift combustion and back combustion can be prevented, and a proportional control range can be set broadly.

〔Effect of the invention〕

According to the present invention, even if there are variations in the blower or components, the required maximum air volume and minimum air volume can be easily controlled via a variable resistor, thereby preventing υ lift combustion and back combustion. , and the proportional control range can be set widely.

[Brief explanation of the drawing]

The figure shows one embodiment of the present invention, FIG. 1 is a schematic configuration diagram in which the proportional combustion device according to the invention is applied to a hot water heater, FIG. 2 is a control circuit diagram of the blower drive motor in FIG. 1, FIG. 3 is a flowchart of the blower rotation speed. 8... Full-order burner 10... Zero cabana 1
2...Blower 14...Microcomputer 1
5, lb...e = Engineering variable resistor 18... Blower drive motor. $1 Garden Z Mathematics Zrn 4

Claims (1)

[Claims] In a proportional combustion device consisting of a blower, a zero governor that controls the amount of gas according to the airflow rate of the blower, a microcomputer that controls the rotation speed of the blower, and a burner, two controllers are used to correct the maximum and minimum rotation speeds of the blower. A proportional combustion device characterized in that a variable resistor is provided at an input terminal of a microcomputer.