JPS621169B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pot-type combustion apparatus, and more particularly to a pot-type combustion apparatus in which fuel supplied to a pot-type combustor at startup is ignited by an ignition heater.

Conventionally, in this type of device, the following method has been used to control the amount of fuel supplied to the pot-type combustor. That is, one method uses an oil amount regulator equipped with an oil level regulator to supply fuel to the combustor based on the level difference between the level of the oil level regulator and the bottom of the combustor. One method uses a quantitative electromagnetic pump and an overflow pipe to pump up a fixed amount of fuel and supply it to the bottom of the combustor.

However, according to the conventional system, if an oil stagnation occurs in the combustor at the time of startup, abnormal combustion occurs after ignition, resulting in soot generation and local overheating of the combustion device. Moreover, in the case of an electromagnetic pump type, an overflow pipe must be provided to prevent fuel from overflowing outside the combustor, which could result in continued supply of fuel without ignition due to a malfunction in the ignition system. Another structural problem was that a fuel tank had to be installed below the combustor to return fuel.

The present invention was invented in view of the above problems, and its purpose is to prevent abnormal combustion by reliably detecting abnormal conditions in the ignition system at the time of starting operation and oil pools in the combustor. The object of the present invention is to provide a pot-type combustion device that does not generate heat. In particular, when an electromagnetic pump is used, the pot-type combustion apparatus eliminates the need for an overflow pipe and eliminates restrictions on the installation of a fuel tank.

That is, the device of the present invention is a pot-type combustor in which a fuel supply pipe is connected to a pot-type combustor to supply fuel to the bottom of the combustor. an ignition heater whose electrical resistance changes depending on the size of the fuel pool at the bottom, and a current detector that detects a current that changes based on a change in the electrical resistance of the ignition heater depending on the size of the fuel pool at the bottom. The present invention is characterized in that the fuel supply pipe is provided with fuel supply control means for controlling the fuel supply amount by operating or stopping the operation based on the output from the current detector.

Embodiments of the device of the present invention will be described below based on the drawings.

In the drawing, 1 is a combustion housing, and a partition plate 2 is provided at an intermediate position in the vertical direction.
An air chamber 3 for combustion air is formed below the partition plate 2, and a combustion chamber 4 is formed above the partition plate 2. Then, the central part of the partition plate 2 is opened, and the pot-type combustor 5 is installed in the air chamber 3 at the lower part of the opening, and a large number of intake holes 6 are provided in the peripheral wall of the combustor 5. The air in the combustion chamber 3 is sucked into the combustor 5 through these intake holes 6.

The air chamber 3 is provided with a combustion air supply pipe 7.
At the same time, a combustion gas exhaust pipe 8 is connected to the upper part of the combustion chamber 4.

Accordingly, the present invention provides a pot-type combustion apparatus configured as described above, in which the pot-type combustor 5 includes:
The combustion supply pipe 9 is connected to supply fuel to the bottom of the combustor 5, and an ignition heater 10 whose electrical resistance changes depending on the temperature is located at the bottom and immersed in the fuel supplied to the bottom. is provided so that the temperature of the ignition heater 10 changes depending on the size of the fuel pool at the bottom.

That is, the heat generating portion 10' of the ignition heater 10 is installed in an inclined manner at the bottom of the combustor 5, and when the fuel pool is large, the heat dissipation of the ignition heater 10 is good, the temperature rise is low, and the fuel pool is reduced. The ignition heater 10 is provided in such a way that if it is small, the heat dissipation of the ignition heater is poor and the temperature rise becomes large. The resistance changes with the temperature change of the ignition heater 10, and the current based on this resistance change is detected to control the fuel supply from the fuel supply pipe 9.

That is, in the case shown in FIG. 1, the fuel tank 11
A metering type electromagnetic pump SP is connected to the pump, a fuel supply pipe 9 connected to the combustor 5 is connected to the discharge port of the electromagnetic pump SP, and the fuel in the fuel tank 11 is pumped up by operating the electromagnetic pump SP. Thus, a fixed amount of fuel is supplied to the bottom of the combustor 5 through the fuel supply pipe.

And an ignition heater 1 provided at the bottom of the combustor 5
0 used a so-called ceramic heater in which a tungsten printed wire was supported by being sandwiched between two ceramic bodies, and it had heat resistance.
It can directly apply a voltage of 100V without lowering the voltage with a transformer, has a large and positive temperature coefficient of electrical resistance, and has the ability to increase or decrease electrical resistance R (T) in accordance with increases or decreases in temperature T. That's what I'm doing.

However, at the start of operation, the fuel supply to the combustor 5 is controlled depending on the size of the oil pool in the combustor as described above, so in FIGS. 1 and 2, instead of directly detecting the temperature T of the ignition heater 10, Since there is a relationship of I∝1/R(T) between the temperature T and the current I flowing through the ignition heater 10, a current detector 12 is provided to detect the current I flowing through the ignition heater 10. When the temperature T is below a predetermined value, that is, the current I is a predetermined value.
When I ₀ or more, the output of the detector 12 de-energizes the electromagnetic pump SP to stop fuel supply.

More specifically, the current detector 12 uses a current transformer, and the primary side of the current transformer is installed in series with the ignition heater 10, and the secondary side is connected to each device described below. It is configured to perform the following three functions.

That is, the first function is to activate the ignition heater 12 at the start of operation.
This function is to prevent fuel supply when the current transformer is disconnected, and a relay Ry is provided on the secondary side of the current transformer, and the normally closed contact Ry-1 of the relay Ry is connected in series with the circuit of the electromagnetic pump SP. Ignition heater 1
0, the contact Ry-1 is opened to keep the electromagnetic pump SP stopped and not to supply fuel.

The second function is to prevent fuel from being supplied if fuel has already accumulated in the combustor 5 at the start of operation, even if the ignition heater 10 is normal and has no disconnection. Set time on the secondary side of
A first timer T ₁ is provided with t ₁ set to 5 seconds, for example, and when the timer T ₁ is activated 5 seconds after the start of operation and the ignition heater 10 is energized, an excessive amount of fuel has already been stored. If the current applied to the ignition heater 10 does not drop to the set value _I1 , the relay Ry is energized to keep the electromagnetic pump SF stopped and no fuel is supplied.

The third function is to stop the fuel supply if excessive fuel is supplied during the starting operation when the ignition heater 10 is normal with no wire breakage and there is no excessive accumulation of fuel at the start of operation. This function is designed to stop the In other words, a second timer is installed on the secondary side of the current transformer.
If timer T ₂ is set and the set time t ₂ is set to, for example, 40 seconds, and 40 seconds have elapsed after the start operation has started normally, and the timer T ₂ is activated, the fuel will not be supplied even though the ignition is not sufficient. If the current flowing to the ignition heater 14 does not decrease to the set value I ₂ (however, I ₂ < I ₁ ), the relay Ry is energized and the electromagnetic pump SP is stopped. The fuel supply will be stopped. Furthermore, in any of the above functions, when the relay Ry operates, it means that there is an abnormality in the ignition heater 10, the air system (not shown), or something else, so the energization of the ignition heater 10 is also stopped in order to stop the operation of the combustion device. It is stopped.

Reference numerals 14 and 15 denote power sources, and Th denotes a temperature regulator that opens when the combustion temperature in the combustor 5 rises to a certain value after the start of operation, and de-energizes the ignition heater 10 to shift to steady operation.

However, in the above configuration, if the ignition heater 10 is disconnected when the operation switch (not shown) is turned on to start operation, no current flows through the heater 10, so the current detector 12 Since the relay Ry is energized and the contact Ry-1 is opened, the electromagnetic pump SP does not operate and the fuel supply can be stopped.

Furthermore, even if the ignition heater 10 is not disconnected and is normal, if fuel has accumulated above the set value at the start of operation, the ignition heater 1
When the current flowing through the relay 0 is larger than the predetermined value _I1 , the relay Ry is energized by the operation of the first timer _T1 of the current detector 12, and the fuel supply can be stopped in the same way.

Furthermore, if the ignition heater 10 is normal and an appropriate amount of fuel is being supplied to the combustor 5, the current flowing through the ignition heater 10 will be smaller than the predetermined value _I1 5 seconds after the start of operation, so the first timer _T1 will be When activated, the relay Ry is not excited, but the electromagnetic pump SP is activated, a fixed amount of fuel is supplied, and ignition is performed by the ignition heater 10.

When, for example, 40 seconds have elapsed since the engine started operating, if too much fuel has been supplied and the current flowing through the ignition heater 10 is greater than the predetermined value _I2 , the second current detector 12 The relay Ry is energized by the operation of the timer _T2 , and the electromagnetic pump SP stops operating, so that the fuel supply can be stopped.

Also, when 40 seconds have passed since the start of operation, the appropriate amount of fuel has accumulated without excessive accumulation, and the ignition heater
When the current flowing through the relay is smaller than the predetermined value _I2 , the relay
With Ry remaining de-energized, the electromagnetic pump SP continues to operate, and a fixed amount of fuel is supplied, allowing normal startup operation to continue.

That is, the starting operation can be performed reliably without fear of excessively supplying fuel to the combustor 5 during the starting operation, and the supplied fuel can be reliably brought into a combustion state.
The ignition heater 10 is turned off by turning off the temperature controller Th.
It is possible to de-energize and shift to steady operation.
Abnormal combustion caused by oil pools can be reliably prevented.

In addition, in the above explanation, a metering type electromagnetic pump is used as a method for controlling the amount of fuel supplied to the combustor 5.
Although this method has been applied to a system using SP, even when applied to various other systems, starting operation can be performed reliably without fear of supplying too much fuel to the combustor 5 during starting operation. For example, when using a constant oil level regulator, a solenoid valve is interposed in the fuel supply pipe 9 instead of the solenoid pump SP to control opening and closing of the solenoid valve.

Also, the ignition heater 1 in the electric circuit described above
As shown in Figures 3 and 4, the ignition heater 10 is connected to the line of
By interposing a resistor that divides the voltage applied to the engine, the starting time can be shortened.

First, the electric circuit in FIG. 3 is connected to the second timer.
A timer T whose set time is longer than the set time _T2 (=40 seconds) of _T2 , for example, 45 seconds _, is formed, and the ignition heater 10 is connected to the normal terminal C of the changeover switch 13 in the timer T. However, the switching terminal a, which is open at the time of starting, is connected to the power line via a fixed resistor _r1 , and the switching terminal b, which is closed at the time of starting, is connected directly to the power line.

That is, at the start of operation, the ignition heater 10 as shown in FIG.
Since a high voltage V ₁ higher than the rated voltage Vo is applied to the rated voltage V 1 to generate heat higher than the rated output, the temperature of the ignition heater 10 is changed as shown in FIG. 7 by a solid line along the temperature rise curve of the high voltage V ₁ . As shown in the figure, the heating temperature can be quickly raised to the set heating temperature K. When the temperature rises in this way, the changeover switch 13 of the timer T is operated to connect the resistor _r1 in series to the ignition heater 10, and the rated voltage Vo is applied to the ignition heater 10, which is indicated by a solid line hereinafter. The heating temperature can be quickly raised to the set heating temperature K. When the temperature rises in this way, the changeover switch 13 of the timer T is operated to switch the ignition heater 10.
The resistor _r1 is connected in series to the ignition heater 10.
Since the rated voltage Vo is applied to the ignition heater 10, the set heating temperature K can be maintained as shown by the solid line.The fuel can be quickly ignited without overheating the ignition heater 10, and the starting time can be shortened. be.

Furthermore, the electric circuit shown in FIG.
A parallel circuit consisting of a fixed resistor _r2 and a semiconductor resistor P is connected in series with . Note that the semiconductor resistor P
has a positive temperature coefficient with a Curie point, and has the characteristic that it self-heats up to the Curie point and its resistance value increases as the temperature increases.

That is, while the time _t3 elapses after the start of operation, the voltage applied to the ignition heater 10 decreases from the high voltage _V1 , which is higher than the rated voltage Vo, to the rated voltage Vo, as shown in FIG.
As a result, the temperature of the ignition heater 10 rapidly rises to the set heating temperature K at a faster rate than the temperature rise curve when the applied voltage is the rated voltage Vo, as shown by the dashed line in FIG. made to do,
Moreover, after the time _t3 has elapsed, the temperature K can be maintained at the temperature K, so that the fuel can be quickly ignited without overheating the ignition heater 10, and the starting time can be shortened.

As described above, according to the present invention, the ignition heater is heated by using an ignition heater whose electric resistance changes depending on the size of the fuel pool provided at the bottom of the pot-type combustor at a position immersed in the fuel supplied. By controlling the fuel supply amount using the output from a current detector that detects the current that changes based on changes in the electrical resistance of the In a situation where the fuel supply should be stopped, such as when the ignition is malfunctioning or a large amount of fuel accumulates, there is a risk that the fuel supply can be stopped with certainty and too much fuel may be supplied. Abnormal combustion can be reliably prevented without any problems, and when using a quantitative electromagnetic pump, for example, it is possible to completely eliminate restrictions on the use of an overflow pipe and the installation of a fuel tank.

Furthermore, as mentioned above, when controlling the amount of fuel supplied to prevent oil accumulation in the combustor, electricity is Using the ignition heater itself, which has a variable resistance, the current detector detects the current that changes based on the change in electrical resistance of the ignition heater depending on the size of the fuel pool, so it is possible to detect the oil pool in the combustor. Detection can be made more reliably, and abnormalities in the heater, air system, etc. can be discovered.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing an embodiment of the present invention, Fig. 2 is an electric circuit diagram, Figs. 3 and 4 are electric circuit diagrams showing other embodiments, and Figs. 5 and 6 are the same as Figs. The applied voltage characteristic diagram and FIG. 7 are the temperature rise characteristic diagram. 5...Pot type combustor, 9...Fuel supply pipe, 1
0...Ignition heater, 12...Current detector.

Claims (1)

[Claims] 1 Connect the fuel supply pipe to the pot-type combustor,
In the pot-type combustion device that supplies fuel to the bottom of the combustor, an ignition heater is provided at the bottom and at a position immersed in the fuel supplied to the bottom, the electrical resistance of which changes depending on the size of the fuel pool; A current detector is provided in the fuel supply pipe to detect a current that changes based on a change in electrical resistance of the ignition heater depending on the size of the fuel pool at the bottom, and the fuel supply pipe is operated or operated by the output from the current detector. What is claimed is: 1. A pot-type combustion device characterized by comprising fuel supply control means for controlling the amount of fuel supplied by stopping the fuel supply.