JPH01107008A - Liquid fuel burner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Fields of Use The present invention is applicable to home use such as heating equipment, or to commercial use.
The present invention relates to a liquid fuel combustion device for use in this field.

BACKGROUND OF THE INVENTION In recent years, efforts have been made to expand the variable range of the combustion amount of combustion devices while improving the exhaust gas characteristics. As a means of achieving this, we have succeeded in greatly improving the above characteristics by using a combustion device in which a large number of flame ports are placed facing each other.

An example of the above-mentioned combustion device will be described below with reference to the drawings.

FIG. 3 is a sectional view of a conventional combustion device using opposed flames. In FIG. 3, 1 is a fuel nozzle that spouts fuel;
2 is a vaporization cylinder that vaporizes the fuel, 3 is a heater that heats the vaporization cylinder, 4 is a mixing chamber that mixes the vaporized fuel and air, 5 is a fuel passage, 6 is a fuel supply passage branched from the fuel passage, and 7 is a In the flame port, 8 is a combustion chamber wall forming a combustion chamber, and 9 is a flame.

The operation of the combustion apparatus configured as described above will be explained below.

First, when the heater 3 is energized and the vaporization cylinder 2 reaches a predetermined temperature, combustion air and liquid fuel are sent into the vaporization cylinder 2.
The liquid fuel is vaporized by the vaporization cylinder 2 and sent to the mixing chamber 4 while being mixed with air, and the air and vaporized fuel are sufficiently mixed within the mixing chamber 4.

The mixed air-fuel mixture passes through the fuel passage 5 and reaches the lower flame from a number of fuel supply passages 6. When the air-fuel mixture ejected from the flame lower is ignited, a flame 9 is formed. Here, since the flame lowers are provided facing each other, the flame 9
They are formed facing each other as shown in the figure. As a result, even when the amount of air increases or the amount of combustion is large, flame blow-off becomes extremely difficult to occur, and the variable range of the amount of air and the amount of combustion becomes wider.

Problems to be Solved by the Invention However, in the above configuration, since there is a mixing chamber between the vaporization tube and the combustion chamber, the vaporization tube cannot directly receive the amount of heat generated by the flame. Therefore, it is not possible to maintain the temperature required to vaporize the fuel, and the fuel needs to be heated by a heater even during combustion. Therefore, power consumption increases accordingly. In addition, the mixture that comes out of the mixing chamber flows through the fuel passage and branches into the fuel supply passage, but as it flows downstream (the farthest position from the carburetor cylinder), it flows from the combustion chamber, fuel supply passage, etc. The mixture gradually heats up due to heat transfer, resulting in a considerable temperature difference between the air-fuel mixture exiting from the upstream side and the air-fuel mixture exiting from the downstream side. As a result, there is a temperature difference in the flame that is formed and also in the walls of the combustion chamber between the upstream and downstream sides. Therefore, the combustion conditions (largely due to the combustion speed) differ between the upstream and downstream sides, and CO is more likely to be generated or blown away due to incomplete combustion on the upstream side where the temperature is low, while on the upstream side where the temperature is high In this case, NOx emissions increased, and durability problems occurred due to overheating of the combustion chamber wall due to temperature rise.

As a result, when looking at the combustion equipment as a whole,
The original wide combustion range was lost accordingly.

The present invention has been made in view of the problem described in item 1. During steady combustion, it is possible to recover heat from the flame to the vaporization cylinder so that the heater does not need to be energized, and the flow of the air-fuel mixture is By eliminating the temperature difference between the flame and the combustion chamber wall 5 - on the upstream and downstream sides of the combustion chamber and maintaining a uniform combustion state throughout, local generation of CO, blow-off, and increase in NOx emissions can be avoided. , eliminates overheating of the combustion chamber wall,
This realizes combustion with a wide variable range inherent to opposing flames.

Means for Solving the Problems In order to solve the problem described in item 1, the liquid fuel combustion device of the present invention has a vaporizing tube disposed on one side between the walls of a combustion chamber having a large number of flame ports facing each other, By arranging the carburetor cylinder and the fuel passage in a substantially parallel state and connecting the same ends through the mixing chamber, the flow of fuel and air in the carburetor cylinder and the flow of the mixture in the fuel passage are controlled. It is configured to run in the opposite direction.

Effects According to the present invention, with the above-described configuration, a part of the vaporization tube arranged on one side between the walls of the combustion chamber is heated by direct radiant heat from the flame, so that heat recovery from the flame to the vaporization tube is improved. This makes it very easy to maintain the temperature of the vaporizing cylinder at an appropriate level during steady combustion without energizing the heater. Furthermore, to 6-1, on the downstream side of the fuel passage where the temperature of the combustion chamber wall and flame is high,
It is in contact with the inlet side of the vaporization cylinder, which has a low temperature and a large amount of heat absorbed (the inlet side of the vaporization cylinder is where cold air enters and a large amount of fuel is vaporized, so a large amount of heat is absorbed from the surroundings), and the temperature of the combustion chamber wall and flame is low. The lower upstream side is the outlet side of the vaporizer cylinder where the temperature is higher and the amount of heat absorbed is smaller (the outlet side of the vaporizer cylinder is
As the air is also preheated, the amount of fuel vaporized decreases, so the amount of heat absorbed also decreases), so as a result, the temperature of the combustion chamber walls and flame becomes uniform throughout. As a result, local generation of CO, blow-off, increase in NOx emissions, overheating of the combustion chamber wall, etc. are eliminated, and it is possible to achieve this without impairing the wide variable range of combustion amount inherent to opposing flames.

EXAMPLE Hereinafter, a combustion apparatus according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a liquid fuel combustion device in one embodiment of the present invention. In FIG. 1, reference numeral 11 denotes a vaporizing cylinder for vaporizing liquid fuel (indicated by broken lines 7 and -7 in the figure), which is long and thin. 12 is a fuel nozzle that injects liquid fuel into the vaporizer cylinder 11;
It is connected to 3. Reference numeral 14 denotes an air passage that guides fuel air from the blower 15 to the vaporization cylinder 11, and is open to the inlet of the vaporization cylinder 11 together with the fuel nozzle 12. 16 is the carburetor cylinder 11
The mixing chamber is provided at the outlet of the fuel tank 1 and communicates with the fuel passages 17 on both sides. A large number of fuel supply passages 18 are connected to the fuel passage 17.
The other end of this fuel supply path 18 penetrates the combustion chamber wall 19 and opens into the combustion chamber 20, forming a flame port 21. Here, the two combustion chamber walls 19 face each other, and the flame ports 21 are provided at positions facing each other.

22 is the flame formed at the flame port 21, and the flame 2 is coming from both sides.
2 are facing each other.

FIG. 2 is a cutaway perspective view of the combustion apparatus of the present invention, and it can be clearly seen that the carburetor tube 11 is placed between two combustion chamber walls 19 having a large number of flame ports 21. 2 in Figure 2
3 is a heater embedded in the vaporization tube 11, and 24 is a vaporization tube lid that forms a combustion chamber and forms the vaporization chamber together with the vaporization tube 11.

The operation of the liquid fuel combustion apparatus configured as described above will be described below.

First, the heater 23 is energized to heat the vaporization cylinder 11 .

When the vaporization tube 11 reaches a predetermined temperature, the blower 15 is operated and combustion air is sent to the vaporization tube 11 through the air passage 14. Also, the pump.

13 is also activated, and fuel is injected from the fuel nozzle 12 into the carburetor cylinder 11. Since the temperature of the vaporization cylinder 11 is such that the liquid fuel is vaporized, the fuel is vaporized and guided from the outlet of the vaporization cylinder 11 to the mixing chamber 16 while being mixed with the above-mentioned combustion air. In the mixing chamber 16, the fuel and air become a uniform mixture and flow into the fuel passage 17 as indicated by the arrow in FIG.

Further, the air-fuel mixture advances from the fuel passage 17 to the fuel supply passage 1B, which is branched into many branches, and is ejected into the combustion chamber 20 from the opening of the fuel supply passage 18, that is, the flame port 21. This flame outlet 21
When the air-fuel mixture discharged from the engine is ignited, a flame 22 is formed and combustion continues. At this time, radiation from the flame 22 heats the combustion chamber wall 19 and the vaporizer cylinder lid 24 at the same time, causing the vaporizer cylinder 11 to heat up.
is also heated. In this embodiment, the temperature of the vaporizer tube 11 is maintained at a temperature suitable for vaporizing the liquid fuel during combustion by making the distance between the flame 22 and the vaporizer tube 11 or the dimensions of the vaporizer tube lid 24 appropriate. It's starting to drip. That is, during steady combustion, it is possible to maintain a constant temperature without energizing the heater 23.

Furthermore, while passing through the fuel passage 17, the air-fuel mixture is gradually preheated by heat transfer from the combustion chamber wall 19 or the fuel supply passage 1B,
There is a considerable temperature difference between a position close to the mixing chamber 16 and a position downstream, that is, away from the mixing chamber 16. However, the downstream side, where the temperature of the air-fuel mixture becomes high, is close to the inlet side of the vaporizing cylinder, and conversely, the upstream side is close to the outlet side of the vaporizing cylinder. On the inlet and outlet sides of this vaporization cylinder, cold air enters on the inlet side and the opening of the fuel nozzle is located on the inlet side, so the amount of fuel vaporized increases and the amount of heat absorbed from the surroundings increases. As the air progresses toward the outlet side, the air is also preheated and at the same time, the amount of vaporized fuel decreases, so the amount of heat absorbed from the surroundings decreases. Therefore, considering the flame temperature, on the downstream side where the temperature of the mixture is high, the amount of heat absorbed (heat radiation amount) to the vaporization cylinder (inlet side) is large, and conversely, on the upstream side where the temperature of the mixture is low, Amount of heat absorbed into the vaporization cylinder (outlet side) (heat radiation amount)
As a result, there is almost no difference in flame temperature between the upstream and downstream sides. Therefore, the temperature of the flame and the combustion chamber wall becomes uniform throughout, eliminating local imbalances in combustion conditions, eliminating CO generation, blow-off, increased NOx emissions, and overheating of the combustion chamber wall. A wide variable range of the combustion amount inherent to the opposing flames can be realized.

Effects of the Invention As described above, the present invention provides a method in which a vaporizing tube is arranged on one side between two combustion chamber walls having a large number of flame ports facing each other, and the vaporizing tube and a fuel passage are arranged in parallel. By connecting the same ends through the mixing chamber, the flow of fuel and air in the carburetor cylinder is in the opposite direction to the flow of the mixture in the fuel passage 11-7. This makes it easier to recover heat from the combustion chamber, and the temperature of the vaporization cylinder can be maintained at an appropriate level during steady combustion without energizing the heater. Furthermore, local generation of CO, blow-off, increase in NOx emissions, overheating of the combustion chamber wall, etc. are eliminated, and a wide range of variation in the amount of combustion inherent to opposing flames is obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a liquid fuel combustion device according to an embodiment of the present invention, FIG. 2 is a perspective view of the same, and FIG. 3 is a cross-sectional view of a conventional combustion device. 11... Vaporizer cylinder, 16... Mixing chamber, 1
7... Fuel passage, 18... Fuel supply path, 19... Combustion chamber wall, 21... Flame port.

Claims (2)

[Claims] (1) Two combustion chamber walls each having a large number of flame ports are arranged to face each other, with the flame ports facing each other, and each of the flame ports is connected to the outside of the combustion chamber wall through a fuel supply path. A vaporizing cylinder is arranged on one side between the two walls of the combustion chamber, and the vaporizing cylinder and the fuel passage are arranged in a substantially parallel state, and the same end is connected to the fuel passage. A liquid fuel combustion device in which the flow of fuel and combustion air in the vaporizing cylinder and the flow of the mixture in the fuel passage are in opposite directions by communicating through a chamber. (2) The liquid fuel combustion device according to claim 1, wherein the flame ports in the combustion chamber wall are arranged in one row and in a plurality of rows.