JPS6131772B2 - - 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 is possible to switch from preliminary combustion to main combustion by reliably detecting that the temperature necessary for gasifying oil has been obtained. The purpose is to provide an inexpensive and highly reliable vaporization combustion control device that can perform

Next, one embodiment of the 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 a switch 1 is turned on when a heat request occurs, the operating current from the AC power supply 2 first turns on the fan FM. Starts and simultaneously switches on the igniter via switching contact 1K ₁ of the relay.
Operating current is supplied to IG and pre-combustion valve V1. 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 the pre-combustion reaches a temperature sufficient to vaporize the oil, relay contact _1K1 switches, thereby disconnecting the igniter IG and the pre-combustion valve V1 from the power supply and replacing the main combustion Valve V
2 operates, and main combustion begins from this point.

Figure 2 shows a circuit for switching the relay contact _1K1 . The thermistor 5, which detects the temperature of the boiler water that is to be heated by the burner, and the variable resistor VR, which sets the boiler water temperature, constitute a bridge circuit together with the resistors R1 and R2. A predetermined DC voltage is applied to the bridge circuit from a DC power supply 6. Therefore, a potential difference corresponding to the difference between the actual water temperature and the set temperature is generated between point a at one end of the thermistor 5 and point b at one end of the variable resistor VR. This potential difference is detected by the comparator 7 and output as a heat request signal.

Furthermore, a differential amplifier 8 is provided to detect the potential difference between points a and b. That is, the output signal of the differential amplifier 8 has a voltage corresponding to the actual water temperature if the set temperature set by the variable resistor VR is constant, and this signal is supplied to the timer circuit 9. Ru. Since the burner temperature is simulated by the hot water temperature, the voltage of the signal input to the timer circuit 9 also indicates the burner temperature. The timer circuit 9 includes resistors R3, R4,
It consists of a bridge circuit consisting of R5 and a capacitor C1, and a comparator 10 which receives the output of this bridge circuit as an input, and the output of this timer circuit 9 controls a transistor 11 whose collector load is a relay 1K. It's summery. This relay 1K connects its contact 1K ₁ from the igniter IG and preliminary combustion valve V1 side to the main combustion valve V2 side during operation.
switch to the side.

In the device configured in this way, when preliminary combustion is started by the above operation, the temperature of the boiler water gradually rises, so the potential difference between points a and b decreases, and the differential amplifier 8 output voltage decreases. The timer circuit 9 operates at a short timing when the output voltage of the differential amplifier 8 is low, and at a long timing when the output voltage is high.

As described above, according to the present invention, the temperature of the pre-combustion burner can be simulated using hot water from the boiler, and the pre-combustion time is controlled according to the temperature of the hot water. 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 directly measure the temperature of the burner, 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, and FIG. 2 is a circuit diagram of its essential parts. 1... Switch, 2... AC power supply, 3... Wind pressure switch, 5... Thermistor, 7... Comparator, 8... Differential amplifier, 9... Timer circuit, 10
... 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 differential amplifier that detects a potential difference corresponding to the difference between the detected boiler water temperature value and the set value, a timer circuit whose timing changes in response to the output voltage of this differential amplifier, and the output of this timer circuit. A liquid fuel vaporization combustion control device comprising a relay operated by the relay, and configured to switch from preliminary combustion to main combustion when the relay operates.