JPS6131773B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid fuel that has an operation sequence in which a temperature sufficient to gasify oil is obtained through preliminary combustion, and then main combustion with gasified oil begins. This invention relates to a vaporization combustion control device.

In the conventional liquid fuel vaporization combustion control device,
Pre-combustion time is often determined by a conventional timer circuit. However, since the time set in the timer circuit is constant, excess or deficiency may occur due to changes in external conditions. For example, in the winter when the ambient temperature is low, a long pre-combustion is required to heat oil to a temperature sufficient for gasification, whereas in the summer when the ambient temperature is high, a short period of time is required to reach the gasification temperature. Therefore, if the timer circuit setting time were to match the pre-combustion time in the winter, the pre-combustion time would be excessively long in the summer. It has also been considered to detect the end of pre-combustion by detecting the burner temperature, but this requires the use of a temperature sensor that has a quick response and is highly reliable at high temperatures. be at a disadvantage in terms of

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional method, and it reliably detects that the temperature required for oil gasification has been obtained and switches from preliminary combustion to main combustion. The purpose of the present invention is to provide an inexpensive and highly reliable vaporization combustion control device that can perform the following steps.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 schematically shows a liquid fuel vaporization combustion control device according to the present invention.
When switch 1 is turned on when a heat demand occurs, the operating current from AC power supply 2 first turns on fan FM.
is activated, and at the same time an operating current is supplied to the igniter IG and the pre-combustion valve V1 via the switching contact _1K1 of the relay. Also, when the air blow from the fan FM is detected and the wind pressure switch 3 is turned on, operating current is supplied to the fuel pump P via the diode 4, where preliminary combustion begins and heating is performed to vaporize the oil. . When a sufficient temperature is obtained to vaporize the oil through preliminary combustion, contact 1 of the relay
_K1 is switched, thereby disconnecting the igniter IG and the pre-combustion valve V1 from the power supply, and operating the main combustion valve V2 instead, starting main combustion from this point.

Figure 2 shows a circuit for switching the relay contact _1K1 . When the pre-combustion burner ignites in the above operation, its flame is detected by a flame detector, such as a flame rod, and a flame signal is supplied to one input of the comparator 5. This comparator 5 operates to set the output terminal to the H level only when the voltage of the flame signal is higher than the reference voltage set by the voltage dividing resistors R1 and R2. The detection signal is used for predetermined combustion safety control as in a conventional device.

On the other hand, the flame detection signal at the H level passes through the diode D1, passes through a voltage dividing circuit made up of resistors R3 and R4, and charges the capacitor C1. The terminal voltage of the capacitor C1 is impedance-converted by the amplifier 6 and then input to the timer circuit 7 via the diode D2. Timer circuit 7
are resistors R5, R6, R7 and capacitor C2
and a transistor 9 that operates on and off depending on the output state of a comparator 8 which receives the output of the bridge circuit as an input.
As the collector load of this transistor 9, the first
A relay 1K having contacts 1K ₁ shown in the figure is connected. Note that reference numeral 10 indicates a DC power supply for supplying operating current to the above electronic circuit.

In the device configured in this way, when the pre-combustion burner is ignited by the above operation, the output of the comparator 5 becomes H level due to the film signal from the flame detector that detects this, and the output of the capacitor C1 becomes H level. Charging begins. FIG. 3 shows actual measured values of the terminal voltage of the capacitor C1, the output voltage of the amplifier 6, and the temperature of the pre-combustion burner.
As is clear from this result, the burner temperature can be accurately simulated by the charging voltage of the capacitor C1. The timer circuit 7 whose timing is variable according to the output level of the amplifier 6 operates at a short timing when the output level is high, and at a long timing when the output level is low.

As described above, according to the present invention, by utilizing the fact that the burner temperature can be simulated by the charging voltage of the capacitor charged by the flame detection signal of the pre-combustion burner, if the charging voltage of this capacitor is high, the pre-combustion time is It is possible to set the optimum pre-combustion time according to the burner temperature by shortening the pre-combustion time and increasing the pre-combustion time if it is low. Therefore, even if there are fluctuations in the outside temperature, etc., there will be no excess or deficiency in the pre-combustion time.
Further, since there is no need to provide another temperature sensor to detect the burner temperature, reliability is high and it is advantageous in terms of cost.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a vaporization combustion control device according to an embodiment of the present invention, Fig. 2 is a circuit diagram of its main parts, and Fig. 3 is a graph showing changes in voltage at each part in comparison with changes in burner temperature. It is. 1...Switch, 2...AC power supply, 3...Wind pressure switch, 5...Comparator, 6...Amplifier,
7...Timer circuit, 8...Comparator, FM...
...Fan, IG...Igniter, V1...Preliminary combustion valve, V2...Main combustion valve, P...Fuel pump, 1K
...Relay, 1K ₁ ...Contact.

Claims (1)

[Claims] 1. A capacitor that is charged with a flame detection signal generated by detecting the flame of a pre-combustion burner, a timer circuit whose timing changes according to the charging voltage of this capacitor, and the output of this timer circuit. A liquid fuel vaporization combustion control device comprising a relay that operates, and configured to switch from preliminary combustion to main combustion when the relay operates.