JPH0480518A - Method for controlling ignition in pressure atomization burner - Google Patents

Abstract

PURPOSE:To reduce ignition sound and striking sound after ignition by a method wherein an output of a fuel pump is rapidly increased up to a predetermined ignition output value and then ignition is carried out. CONSTITUTION:Upon receiving an instruction of a gradual ignition sequence starting with a push button switch 14 or the like, a fuel pump driving control circuit 13 outputs an ignition lower limit electrical power Wo to a fuel pump 12 and then rapidly increases from a zero point to an ignition point (a) which can be ignited for its pressure increasing. A nozzle 3 to which fuel is supplied from the fuel pump 12 may inject atomized fuel at an ignition lower limit state. In respect to the atomized fuel, an ignition spark is flied through an ignition electrode 5, thereby the ignited state is detected by an ignition sensor 15 comprised of a flame rod or the like. The fuel pump driving control circuit 13 received an ignition sensing signal (c) of the ignition sensor 15 keeps the output power Wo only for several seconds T3 and then an output of the fuel pump 12 is kept at the ignition point (a) as indicated by a solid line (a). Holding for several seconds T3 is performed as required in order to assure a gradual rising after ignition.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an improvement in an ignition control method in a pressure spray burner used in oil water heaters and the like.

[Conventional technology]

Conventionally, a pressure spray burner 1 used in an oil water heater or the like supplies fuel (for example, kerosene) discharged from a fuel pump 2 to a nozzle 3, as shown in FIG. The ignition electrode 5 causes an ignition spark to be ignited on the atomized fuel that has been sprayed towards the vehicle. As the fuel pump 2, an electromagnetic pump whose output (amount of fuel discharged per unit time) can be varied is generally used. Although not shown, the electromagnetic pump consists of a fixed magnetic Orad that is periodically magnetized by half-wave rectified electricity, a plunger that moves forward by being attracted to the magnetized fixed magnetic rod, and a plan that consists of an unmagnetized fixed magnetic rod. a return spring for retracting the jar;
It consists of a cylinder into which a plunger is slidably fitted, a suction valve and a discharge valve connected to the cylinder, and an accumulator for absorbing pulsation provided on the outflow side of the discharge valve. The electromagnetic pump reciprocates the plunger by periodically magnetizing a fixed magnetic rod, and continuously supplies the fuel drawn into the cylinder through the suction valve to the nozzle 3 through the discharge valve and the accumulator. The output of the electromagnetic pump is controlled from 0% to 100% by varying the power that magnetizes the fixed magnetic rod from zero to a predetermined upper limit. Conventionally, ignition control of the pressure spray burner 1 involves increasing the output of the fuel pump 2 almost linearly from 0% toward 100%, as shown in the graph of output versus time for the fuel pump 2 in FIG. , the method was to ignite the ignition by blowing an ignition spark at an ignition point ■.

[Problems to be Solved by the Invention] However, in the conventional ignition control method, the ignition point
The unburnt atomized fuel sprayed in area A before reaching the ignition point burns all at once, which has the disadvantage of generating a loud ignition noise. Furthermore, in conventional ignition control methods,
100% output from ignition point in fuel pump 2
Since the valve speed is high in terms of output, there is a drawback that combustion after ignition increases rapidly and generates loud impact noise. Especially,
Ignition noise and post-ignition impact noise tend to increase as the combustion chamber 4 becomes more compact. SUMMARY OF THE INVENTION In order to solve the above-mentioned drawbacks, the present invention aims to provide an ignition control method for a pressure spray burner that can reduce ignition noise and post-ignition impact noise.

[Means for Solving the Problems] The first means adopted in the ignition control method for a pressure spray burner according to the present invention (hereinafter referred to as the method Δ of the present invention) in order to reduce ignition noise is a variable output type In the ignition control method for a pressure spray burner, the fuel discharged from the fuel pump is supplied to a nozzle, and the atomized fuel sprayed from the nozzle toward combustion is ignited by flying an ignition spark. The purpose of this is to raise the ignition output value at once to a predetermined ignition output value and ignite it. The second means adopted by the method of the present invention to reduce ignition noise is to supply fuel discharged from a variable output fuel pump to a nozzle, and ignite the atomized fuel sprayed from this nozzle toward combustion. In the ignition control method for a pressure spray burner that ignites by blowing a spark, the output of the fuel pump is suddenly increased to a predetermined lower limit output value for ignition, the ignition spark is blown, and the ignition condition is detected within a short period of time. In this case, the output of the fuel pump is increased by an appropriate step value. A third means adopted by the method of the present invention to reduce ignition noise and post-ignition impact noise is to gradually reduce the output of the fuel pump after detecting ignition in the first means or the second means. It is to raise it. [Function] In the first means, the output of the fuel pump increases all at once to a predetermined ignition output value, so the unburned atomized fuel that is sprayed before ignition becomes very sensitive, and the ignition noise is reduced. can be reduced. The second means is that even when the ignition point rises due to changes in the outside air or fuel temperature, the output of the fuel pump increases at once to a predetermined lower limit output value of ignition, and the output of the fuel pump increases within a short period of time. The ignition point is quickly reached because the ignition detection is increased one step at a time with an appropriate step width. As a result, in the second means, the amount of unburned atomized fuel that is sprayed before ignition is extremely small, and the ignition noise can be reduced. According to the third means, the output of the fuel pump is gradually increased after ignition is detected, so that impact noise after ignition can be reduced.

【Example】

The method of the present invention will be explained below based on embodiments shown in the drawings. 1 to 4 show an embodiment of the method of the present invention, in which FIG. 1 is a graph showing the relationship between the output of the fuel pump 12 (fuel discharge node per unit time) and time; FIG. 3 is a front view showing the pressure spray burner 10 controlled by the method of the present invention, FIG. 3 is a flowchart showing the operation of the fuel pump drive control circuit 13, and FIG. 4 is a voltage waveform diagram for driving the pump. The fuel pump drive control circuit 13 includes a push button switch 1
When a command to start a slow ignition sequence is received at 4 etc., the fuel pump 1 outputs the ignition lower limit power Wo to the fuel pump 12.
The output of No. 2 is increased from zero to the ignition point (■) at which ignition is possible. This lower limit ignition power Wo is determined by an ignition experiment of the corresponding pressure spray burner 10 under standard conditions, and is uniquely determined. fuel pump 1
The nozzle 3 to which fuel is supplied from the nozzle 2 spouts out atomized fuel at the lower limit of ignition. For this atomized fuel, the ignition electrode 5
An ignition spark is blown away, and the ignition state is detected by an ignition detector 15 consisting of a flame rod or the like. Ignition detector 15
The fuel pump drive control circuit 13 receives the ignition detection signal C of
The output power Wo is held for several seconds at T3, and the output of the fuel pump 12 is maintained at the ignition point (2) as shown by the solid line a in FIG. This holding of T3 for several seconds is performed as necessary to ensure a gradual rise after ignition. After holding T3 for several seconds, the output power of the fuel pump drive control circuit 13 is stepped up by an appropriate step width ΔW2 (see FIG. 4), so that the fuel pump 1
2's output is gradually stepped up by ΔP2. Step-up of the output power of the fuel pump drive control circuit 13 is performed by phase control using a thyristor or the like. A gradual step-up of ΔW2 and ΔP2 as one step is performed up to maximum power W3 and 100% output, completing the slow ignition sequence. This step-up is performed slowly enough not to generate odor in the combustion exhaust gas, and the time ΔT2 of one step is, for example, 0.8 seconds. Note that the increase in output power in the fuel pump drive control circuit 13 after ignition is not done step by step by ΔW2, but by ΔW2.
It is also possible to increase continuously at an increase rate determined by W2÷ΔT2. Incidentally, the ignition point of the atomized fuel atomized by the nozzle 3 may be higher than the ignition point due to differences between the outside air and fuel temperature conditions and the standard conditions of the ignition experiment. In this case, even if the output of the fuel pump 12 reaches the ignition point, ignition will not occur. Therefore, if the ignition detector 15 detects that ignition has not occurred, the output power of the fuel pump drive control circuit 13 is changed from the ignition lower limit power Wo to an appropriate step width ΔW1 (see Fig. 4).
As shown by the broken line in FIG. 1, the output of the fuel pump 12 is stepped up by ΔPt from the ignition point. ΔW! A gradual step-up with (ΔP1) as one step is carried out until the ignition detector 15 detects that ignition has been achieved (in the embodiment already shown by the broken line in the figure, only two steps are carried out). ). This step-up is performed within a short time, and the time ΔTt of one step is, for example, 0.4 seconds. When the ignition detector 15 detects ignition, the fuel pump drive control circuit 13 terminates the step-up, holds the output power at the end for several seconds T3 as described above, and reduces the output of the fuel pump 12. Maintain the value at the time of ignition. After holding T3 for several seconds, the output power of the fuel pump drive control circuit 13 is adjusted to an appropriate step width ΔW2 as described above.
By stepping up the fuel pump 12
The output of is gradually stepped up by ΔP2. ΔW
2 and ΔP2 as one step is performed up to maximum power W3 and 100% output, completing the slow ignition sequence. Incidentally, the increase in the output power of the fuel pump drive control circuit 13 after ignition can also be made to increase continuously in the same manner as described above.

【Effect of the invention】

As described in detail above, in the method of the present invention, the output of the fuel pump is suddenly increased to the ignition output value, so that there is no unburned atomized fuel, and the ignition noise can be reduced. Further, in the method of the present invention, the output of the fuel pump is gradually increased after ignition is detected, so that impact noise after ignition can be reduced. As a result, the method of the present invention has the excellent effect of providing a low-noise pressure spray burner.

[Brief explanation of drawings]

1 to 4 show examples of the method of the present invention, in which FIG. 1 is a graph showing the relationship between fuel pump output (fuel discharge amount per unit time) and time, and FIG. 3 is a front view showing a pressure spray burner controlled by the method of the present invention;
The figure is a flowchart showing the operation of the fuel pump drive control circuit, and FIG. 4 is an electric waveform diagram for driving the pump. FIG. 5 is a front view showing a conventional pressure spray burner, and FIG. 6 is a graph showing the relationship between fuel pump output and time in a conventional control method. 5... Ignition electrode 10... Pressure spray burner 12... Fuel pump 15... Ignition detector 13
...Fuel pump drive control circuit patent applicant Inax Co., Ltd. Agent Patent attorney 1) Toshihiko Figure Time 3 Figure Figure

Claims (1)

[Scope of Claims] 1. A pressure spray burner that supplies fuel discharged from a variable output fuel pump to a nozzle, and ignites the atomized fuel sprayed from the nozzle toward a combustion chamber by emitting an ignition spark. An ignition control method for a pressure spray burner, characterized in that the output of the fuel pump is suddenly increased to a predetermined ignition output value to cause ignition. 2. An ignition control method for a pressure spray burner in which fuel discharged from a variable output fuel pump is supplied to a nozzle, and the atomized fuel sprayed from the nozzle toward the combustion chamber is ignited by an ignition spark, The output of the fuel pump is increased at once to a predetermined lower limit output value for ignition, the ignition spark is blown, and the output of the fuel pump is increased one step at a time with an appropriate step width within a short period of time until the ignition state is detected. Features: Ignition control method for pressure spray burners. 3. The ignition control method for a pressure spray burner according to claim 1 or 2, wherein the output of the fuel pump is gradually increased after the ignition is detected.