JPH10311532A - Liquid fuel vaporizing combustion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vaporizing combustion apparatus which enables preheating of a burner head in a short time and at a lower running cost. SOLUTION: This liquid fuel vaporizing combustion apparatus detects the temperature of a burner head 10 with a second thermistor 34. A controller 30 alters the setting of an air quantity adjusting damper 25 so that a primary air ratio in a mixed gas is increased to turn flame 36 yellow or to reduce a combustion load by properly controlling a pilot burner 18, a feed liquid pump 23, the air quantity adjusting damper 25 or the like. This enables increase in the radiation heating value and direct electrically heating value which the burner head 10 receives from the flame 36.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid fuel vaporization and combustion apparatus (hereinafter referred to as "vaporization and combustion apparatus") which vaporizes liquid fuel such as kerosene and burns it with a burner head.

[0002]

2. Description of the Related Art In a vaporization and combustion apparatus, gaseous fuel obtained by vaporizing liquid fuel by a vaporizer is mixed with air (primary air) separately supplied in a mixing chamber, and the thus obtained air-fuel mixture is obtained. Is sent to the burner head. Then, when the air-fuel mixture is ignited by an ignition means such as an igniter, the air-fuel mixture starts burning and a flame is generated.

When a flame is formed as described above, the temperature of the burner head increases due to heat (radiant heat or direct heat transfer) received from the flame. However, immediately after the occurrence of the flame, the temperature of the burner head is about room temperature, which is lower than the vaporization temperature of the liquid fuel. Therefore, until the temperature of the burner head becomes sufficiently high, the gaseous fuel in the air-fuel mixture condenses on the surface of the burner head, the inner wall surface of the air-fuel mixture jet port provided in the burner head, and the like.

[0004] When gaseous fuel condenses on the burner head, there are the following problems. For example, when kerosene is used as the liquid fuel, the kerosene condensed in the burner head or the like as described above is oxidized and deteriorates. Since the altered kerosene contains a large amount of polymerized high-boiling components, the kerosene does not easily evaporate and remains on the burner head or the like, gradually tarifies and adheres to the burner head or the like. When such tar adheres to the inner wall surface of the air-fuel mixture jet, the air-fuel mixture jet is eventually closed. Also, kerosene condensed on the surface of the burner head or the inner wall surface of the air-fuel mixture outlet flows down and accumulates in the vaporization and combustion device due to gravity even if it does not turn into tar, and eventually leaks out of the device. Furthermore, kerosene condensed on the surface of the burner head or on the inner wall surface of the air-fuel mixture jet port is slightly vaporized after the end of combustion and emits an odor.

In view of the above problems, conventionally, in order to prevent gaseous fuel from condensing on the burner head,
At startup, the burner head is heated by a heating means such as a heater, and after the burner head has reached a sufficiently high temperature, an air-fuel mixture is generated, supplied, and ignited.

[0006]

In order to prevent condensation of gaseous fuel, it is necessary to raise the temperature of the burner head to about 150 ° C., but the heater is used to heat the burner head from room temperature to the above temperature. In this case, a time of about 3 minutes is required, which is one of the causes of prolonging the ignition time. Of course, the heating time can be shortened by increasing the amount of power to the heater. However, in ordinary households, since there is an upper limit to the power that can be used at the same time, for example, 15 A and 20 A, an excessive amount of electricity to the heater may hinder the use of other electric appliances. In general, heating by a heater has a problem that the running cost is large. From this point, it is not preferable to increase the amount of electricity.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and an object of the present invention is to provide a vaporized combustion system capable of preheating a burner head in a short time and at a low running cost. It is to provide a device.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a vaporization and combustion apparatus according to the present invention produces a gaseous fuel by vaporizing a liquid fuel, and mixes the gaseous fuel with air. In a liquid fuel vaporization and combustion apparatus that generates an air-fuel mixture and burns the air-fuel mixture with a burner head, a temperature detector that detects the temperature of the burner head and a temperature detector that detects the temperature of the burner head detected by the temperature detector. And combustion state changing means for changing the combustion state accordingly.

[0009] Another vaporization and combustion apparatus according to the present invention includes:
In a liquid fuel vaporization and combustion apparatus in which a liquid fuel is vaporized to generate a gaseous fuel, the gaseous fuel is mixed with air to generate an air-fuel mixture, and the air-fuel mixture is burned by a burner head, the gaseous fuel is vaporized. It is characterized by comprising a time measuring means for measuring an elapsed time after ignition, and a combustion state changing means for changing a combustion state according to the time measured by the time measuring means.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS When a mixture of gaseous fuel and air is burned on a burner head, the amount of heat (radiant heat, direct heat transfer) received by the burner head from a flame generated on the burner head by the combustion is a combustion state. It changes with. Among the present inventions utilizing this, the vaporizing combustion apparatus according to the first invention detects the temperature of the burner head by the temperature detecting means, and the combustion state changing means appropriately changes the combustion state according to the temperature of the burner head. By doing so, the temperature of the burner head is adjusted.

For example, the combustion state changing means appropriately changes the combustion state when the temperature of the burner head detected by the temperature detection means is lower than a predetermined temperature to increase the amount of heat received by the burner head from the flame. It can be configured as follows. By doing so, the following effects can be obtained.

In a conventional evaporative combustion apparatus, when a burner head is to be heated only by heat (radiant heat or direct heat transfer) generated by burning gaseous fuel without using a heater, the amount of heat is Simply performed normal combustion (that is, combustion aimed at producing hot water) without considering the phenomenon that the burner head changes depending on the combustion state, so it takes a long time for the burner head temperature to rise sufficiently. As a result, a large amount of gaseous fuel was condensed on the burner head.

On the other hand, if the combustion state changing means is constituted as described above, after the gaseous fuel starts burning on the burner head, the combustion state changing means is maintained while the temperature of the burner head is lower than a predetermined temperature. Since the means changes the combustion state so that the amount of heat received by the burner head from the flame increases, the temperature of the burner head can be raised to a sufficiently high temperature in a much shorter time than before, and thus the burner head can be increased. The amount of gaseous fuel condensed on the head can be reduced to a much smaller amount than before.

As one mode of the vaporization combustion apparatus according to the present invention, there is provided an air amount adjusting means for adjusting an amount of air mixed with the gaseous fuel, and the combustion state changing means is provided on the burner head. After the gaseous fuel starts burning, while the temperature of the burner head is lower than the predetermined temperature, the burner head is controlled from the flame by appropriately controlling the air amount adjusting means to reduce the ratio of air contained in the air-fuel mixture. There is a vaporization and combustion device characterized by increasing the amount of radiant heat received.

In another aspect of the evaporative combustion apparatus according to the present invention, the apparatus further comprises a combustion load adjusting means for adjusting a combustion load in the burner head, wherein the combustion state changing means includes a gaseous combustion device on the burner head. After the fuel starts burning, while the temperature of the burner head is lower than a predetermined temperature, the combustion load adjusting means is appropriately controlled to reduce the combustion load, so that the amount of radiant heat and direct heat transferred to the burner head from the flame is reduced. Is increased.

[0016] Further, a vaporization and combustion apparatus according to the second invention comprises:
The elapsed time after ignition of the gaseous fuel is measured by a timer, and the combustion state changing means changes the combustion state in accordance with the elapsed time. For example, the combustion state changing means changes the combustion state so that radiant heat from the flame and / or direct heat transfer increases until a predetermined time elapses after ignition, and after the predetermined time elapses, the set combustion amount To a combustion state corresponding to Such an evaporative combustion apparatus is based on the combustion state (determined based on the flow rate of liquid fuel, the flow rate of primary air, etc.) and the elapsed time after ignition without using a temperature detecting means such as a thermistor. This can be used when the change in the temperature of the burner head can be sufficiently grasped (for example, when the evaporative combustion device is installed in a place where the change in the temperature is relatively small). In the evaporative combustion apparatus according to the second aspect of the invention, the combustion state changing means can be configured using the air amount adjusting means and the combustion load adjusting means described in the various aspects of the first aspect of the invention.

The specific structure and effect of the vaporization and combustion apparatus of each of the above embodiments will be described in detail in embodiments described later with reference to the drawings.

[0018]

According to the evaporative combustion apparatus of the present invention, the temperature of the burner head can be adjusted without using a heater, so that the running cost can be reduced. Also, since the burner head is heated by radiant heat from the flame or direct heat transfer, the temperature of the burner head is reduced to a temperature at which the gaseous fuel does not condense in a shorter time than when the burner head is heated by the heat generated by the heater. Can be raised up.

[0019]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of a vaporization combustion apparatus according to the present invention. In this evaporative combustion apparatus, a burner head 10 having a number of air-fuel mixture jets 11 is provided.
An igniter 13 is provided on the upper surface of the igniter. A mixing chamber 12 is provided directly below the burner head 10, and the mixing chamber 12 communicates with a vaporization chamber 14 disposed immediately below the mixing chamber 12. A vaporizer 16 is provided at the bottom of the vaporization chamber 14, and a pilot burner 18 is disposed immediately below the vaporizer 16. The pilot burner 18 may be a known type, such as a burner of a type (pressure atomization type) in which liquid fuel is pressurized, sprayed from a nozzle, ignited and burned.

Next, looking at the fuel supply system, the end of the liquid feed pipe 22 is immersed in the liquid fuel 21 stored in the fuel tank 20. A liquid sending pump 23 is provided in the middle of the liquid sending pipe 22. The tip of the liquid feed pipe 22 is inserted into the vaporization chamber 14 and faces the upper surface of the vaporizer 16.

Next, looking at the blower system, one end of a blower tube 24 in which a flow rate adjusting damper 25 is disposed is connected to a fan 27. On the other hand, the other end of the blower tube 24 is connected to the vaporization chamber 14.
A first branch pipe 26 for supplying primary air to the burner head 10, and a second branch pipe 28 for supplying secondary air to the burner head 10.
And branch into.

The control device 30 controls the operation of the pilot burner 18, the liquid feed pump 23, and the air volume adjustment damper 25 as appropriate according to the output signals of the first thermistor 32 and the second thermistor 34.

The operation of the evaporative combustion apparatus having the above configuration at the time of ignition will be described. First, when the pilot burner 18 starts combustion according to an instruction from the control device 30, the carburetor 1
The temperature of 6 starts to rise. At this time, the control device 30 monitors the temperature of the vaporizer 16 based on the output signal of the first thermistor 32. When the monitored temperature reaches a predetermined temperature (about 250 ° C. when the liquid fuel is kerosene), the control device 30 starts the liquid feed pump 23 and the fan 27. Fan 27
Is activated, the primary air is blown into the blower pipe 24, the first branch pipe 2
6 and into the mixing chamber 12 through the vaporization chamber 14. On the other hand, when the liquid supply pump 23 is started, the fuel tank 2
The liquid fuel 21 stored at 0 is sucked into the liquid sending pipe 22. The sucked liquid fuel 21 is dropped on the upper surface of the vaporizer 16 from the tip of the liquid feed pipe 22, obtains heat therefrom, is instantaneously vaporized, and diffuses into the vaporization chamber 14 as gaseous fuel. This gaseous fuel flows into the mixing chamber 12 together with the primary air, where it is mixed with the primary air. The air-fuel mixture thus obtained is jetted from the air-fuel mixture jet port 11 provided on the burner head 10 to the upper surface of the burner head 10. When this air-fuel mixture is ignited by the igniter 13, the air-fuel mixture starts burning and a flame 36 is generated.

After the air-fuel mixture starts burning on the burner head 10, the control device 30 monitors the temperature of the burner head 10 based on an output signal from the second thermistor 34, and the temperature is set to a predetermined temperature (for example, liquid). If kerosene is used as fuel, it is determined whether the temperature is higher or lower.

Immediately after the start of combustion, the temperature of the burner head 10 is lower than the predetermined temperature because the burner head 10 hardly absorbs the heat from the flame 36. For this reason, the control device 30 controls the pilot burner 18 and the liquid feed pump 23
In addition, the operation of the air volume adjustment damper 25 is appropriately controlled so that the amount of radiant heat or direct heat transfer received by the burner head 10 from the flame 36 is increased.

A method of adjusting the amount of radiant heat from the flame 36 and the amount of direct heat transfer will be described with reference to FIGS.

FIG. 2 is a diagram for explaining a method of adjusting the radiant heat received from the flame 36 by the burner head 10 by changing the primary air ratio in the air-fuel mixture. When a mixture of gaseous fuel and primary air is burned, the flame 36 becomes yellow flame when the ratio of the primary air contained in the mixture is small (FIG. 2A), and when the ratio of the primary air is large, the flame 36 becomes yellow. Becomes a blue flame (FIG. 2B). Comparing yellow and blue flames, it is yellow flame that contains more radiation (eg, infrared) that is absorbed by an object and converted to thermal energy. Therefore, when the temperature of the burner head 10 is lower than the predetermined temperature, the primary air ratio in the air-fuel mixture may be reduced to generate yellow flame. By doing so, the amount of radiant heat received by the burner head 10 increases, and the temperature of the burner head 10 quickly rises.

FIG. 3 is a view for explaining a method of adjusting the radiant heat and the direct heat transfer that the burner head 10 receives from the flame 36 by changing the combustion load. When the combustion load is increased, the flow rate of the air-fuel mixture ejected from the air-fuel mixture jet port 11 is large, so that the flame 36 spreads upward due to the airflow as shown in FIG.
It becomes thin near 0. In such a state, the amount of combustion near the burner head 10 is small.
The amount of radiant heat received from the flame 36 and the amount of direct heat transfer are reduced. Further, since the flow rate of the air-fuel mixture is large, the amount of heat taken from the burner head 10 by the air-fuel mixture is also large. For the reasons described above, when the combustion load is large, the temperature of the burner head 10 cannot be rapidly increased by radiant heat from the flame 36 or direct heat transfer.

On the other hand, when the combustion load is reduced, the entire flame 36 approaches the burner head 10 as shown in FIG.
6 and the amount of radiant heat and the amount of direct heat transfer increase. Therefore, when the temperature of the burner head 10 is lower than the predetermined temperature, if the combustion load is reduced, the amount of radiant heat and direct heat transfer received by the burner head 10 increases, and the temperature of the burner head 10 rapidly rises. .

By doing so, the radiant heat and direct heat transfer received by the burner head 10 from the flame 36 increase. As a result, the temperature of the burner head 10 rises rapidly and reaches a temperature at which the gaseous fuel does not condense in a short time. Since the amount of gaseous fuel that condenses on the burner head 10 during such a short period of time is small, the above-described problem associated with the condensation does not occur.

FIG. 4 is a diagram showing a schematic configuration of another embodiment of the vaporizing combustion apparatus according to the present invention. In this vaporization and combustion device, the control device 30 includes a timer 37 and a storage unit 38, but does not include the second thermistor 34 provided in the burner head 10 in the vaporization and combustion device of FIG. Other configurations of the apparatus of FIG. 4 are the same as those of the evaporative combustion apparatus of FIG.

In the present embodiment, the control device 3
A value of 0 sends a timing start signal to the timer at the same time as the ignition of the igniter 13, and measures the elapsed time after the ignition. Until the predetermined preheating time elapses, the state of the flame 36 is preheated by the method described above with reference to FIG. 2 or 3, that is, the purpose is to heat the burner head 10 in particular. Maintain burning state. The preheating time is determined by the flame 3 when the burner head 10 is preheated.
6 and the heat capacity of the burner head 10 are taken into consideration and stored in the storage unit 38 of the control device 30 in advance.
After the elapse of the preheating time, the controller 30 changes the settings of the flow rate of the liquid fuel, the combustion rate of the pilot burner 18, the flow rate of the primary air, and the like so that the flame 36 is in a normal combustion state.

The embodiments of the vaporizing combustion apparatus according to the present invention are not limited to the above embodiments, and it goes without saying that various modifications are possible within the spirit and scope of the present invention.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of a vaporization combustion apparatus according to the present invention.

FIG. 2 is a diagram for explaining a method of adjusting radiant heat received from a flame by a burner head by changing a primary air ratio in an air-fuel mixture.

FIG. 3 is a diagram for explaining a method of adjusting radiant heat and direct heat transfer received from a flame by a burner head by changing a combustion load.

FIG. 4 is a diagram showing a schematic configuration of another embodiment of the evaporative combustion apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Burner head 11 ... Air-fuel mixture spout 12 ... Mixing chamber 16 ... Vaporizer 18 ... Pilot burner 21 ... Liquid fuel 25 ... Air flow control damper 27 ... Fan 30 ... Control device 32 ... First thermistor 34 ... Second thermistor 36 ... Flame 37 ... Timer

Continuing from the front page (72) Inventor Hiroshi Ishikawa 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka Prefecture Inside Totoki Equipment Co., Ltd. (72) Inventor Soji Yano 431-1 Uozakihama-cho, Higashinada-ku, Kobe Japan (72) Inventor Koichi Toyoda 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka Prefecture Totoki Kiki Co., Ltd.

Claims (5)

[Claims] Claims: 1. A liquid fuel is vaporized to produce a gaseous fuel,
A liquid fuel vaporization and combustion apparatus for mixing the gaseous fuel and air to generate an air-fuel mixture and burning the air-fuel mixture with a burner head; a temperature detecting means for detecting a temperature of the burner head; And a combustion state changing means for changing a combustion state according to the temperature of the burner head detected by the method. 2. The combustion state changing means, when the temperature of the burner head detected by the temperature detection means is lower than a predetermined temperature, appropriately change the combustion state to increase the amount of heat received by the burner head from the flame. The liquid fuel vaporization and combustion apparatus according to claim 1, wherein: 3. An air amount adjusting means for adjusting an amount of air mixed with the gaseous fuel, wherein the combustion state changing means comprises a gaseous fuel which starts burning after the gaseous fuel starts burning on the burner head. 2. The liquid fuel vaporization and combustion apparatus according to claim 1, wherein while the temperature is lower than a predetermined temperature, the air amount adjusting means is appropriately controlled to reduce the ratio of air contained in the air-fuel mixture. 4. A combustion load adjusting means for adjusting a combustion load in the burner head, wherein the combustion state changing means adjusts the temperature of the burner head to a predetermined temperature after the gaseous fuel starts burning on the burner head. 2. The liquid fuel vaporization combustion apparatus according to claim 1, wherein the combustion load adjusting means is appropriately controlled to reduce the combustion load while the temperature is lower than the temperature. 5. A liquid fuel is vaporized to produce a gaseous fuel.
In a liquid fuel vaporization and combustion apparatus that generates an air-fuel mixture by mixing the gaseous fuel and air and burns the air-fuel mixture with a burner head, a time measuring means for measuring an elapsed time after ignition of the gaseous fuel And a combustion state changing means for changing a combustion state in accordance with the time measured by the time measuring means.