JPH02106603A - combustion device - Google Patents

Abstract

PURPOSE:To supply sufficient heat for vaporizing liquid fuel to a vaporizing material so as to improve the capability and efficiency of combustion by providing a heat- transferring device which cover at least a part of the vaporizing material and by providing heat-transferring devices which are joined with the first-mentioned heat- transferring device and extend from the vaporizing material into a combustion chamber. CONSTITUTION:Heat-transferring rods 31 receive heat from the flame and combustion gas in a combustion chamber 6 and convey the collected heat to a heat-transferring plate 30. Liquid fuel supplied by a fuel feeding pipe 19 enters a vaporizing material 2 through a fuel inlet 20, passes through pores of the vaporizing material, and reaches the surface of the vaporizing material 2. Part of the liquid fuel receives heat at the surface touching the heat-transferring plate 30. The heat transferred form the heat- transferring plate 30 is transmitted by conveyance by the fuel itself and by the vaporizing material to the interior of the body of vaporizing material so as to that the liquid fuel and simultaneously supply heat to the liquid fuel and vaporizing material which are cooled by the heat of vaporization of liquid fuel; thus the vaporization of the liquid fuel is accelerated. The liquid fuel fed into the vaporizing material 2 is entirely vaporized so that its combustion takes satisfactorily without leaving any part unburned.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to relatively small-sized combustion devices that impregnate liquid fuel into a porous vaporized body and burn it, such as an l'' type boiler or a fuel heating device. Regarding etc.

[Conventional technology]

When liquid fuel is burned, it first undergoes a process called evaporation and becomes vaporized.
This is done by reacting fuel vapor with oxygen.

At this time, a vaporizer made of porous ceramics, metal, etc. is used to vaporize the liquid IBM, and the liquid fuel is impregnated with this vaporizer, and the pores are controlled by the surface tension of the liquid, the N force, or the liquid fuel. The liquid reaches the surface of the vaporized body due to the discharge pressure of the pump that delivers the liquid, receives heat from the flame radiation and convection generated by combustion, and evaporates and burns. As a combustion device f1 having such a vaporized body, the one shown in FIG. 4 is conventionally known. As shown in FIG. 2, a vaporizer 2 made of porous ceramic or the like is attached to a cover 5 provided with a plurality of combustion air distribution holes 4 on the -1 peripheral surface of a furnace vessel 3. A vaporizer cover 7 is attached to the vaporizer 2 on the combustion chamber 6 side within the furnace vessel 3. A heat exchanger 9 is provided in the combustion chamber 6 in which the furnace vessel 3 and the inner wall 8 form an annular gas flow path. Note that 11 and 12 are an inlet and an outlet for gas flowing into the heat exchanger 9, and 13 is an outlet from which combustion exhaust gas is discharged.

The fan 15 is provided in a casing 16 surrounding the cover 5, and a fan driving motor 18 having a sudden air intake port 17 is attached to the outside of the casing 16.

19 is a fuel supply pipe, and casing 16. The vaporizer 21 is inserted into a fuel supply port provided through the cover 5. Although not shown, an ignition device is provided.

With such a structure of the combustion device, liquid fuel is supplied from the outside to the fuel supply port (9) of the vaporized body 2 through the fuel supply pipe 19 from the fuel outlet portion 21 by a pump or the like.

The supplied liquid fuel passes through the pores of the vaporized body 2
The fuel reaches the surrounding area, vaporizes and burns due to radiant heat and convection from the combustion of the fuel. At this time, the air necessary for combustion is sucked from the air mass 17 by the fan 15, is energized, passes through the air preheating chamber between the fan 15 and the cover 5, and passes through the air distribution hole 4 to the vaporized body 2. It is blown from the periphery toward the center, mixed with vaporized fuel gas, and combusted.

The combustion gas transfers heat from the inside of the heat exchanger jA8 around the combustion chamber 6 to the heating fluid U flowing through the heat exchanger 9, and is discharged to the outside from the exhaust port 13. The heating fluid U is supplied from the inlet 11 and sent out to the outside via the outlet 12.

In this way, the liquid fuel is vaporized and combusted by the heat generated by combustion in the vaporizer 2. However, with this type of combustion device, there is no need to maintain the vaporized level of the liquid fuel horizontally, so the mounting direction is The advantage is that the flame direction can be freely selected, such as by being able to point the burner downward, and there is no risk of misfires caused by vibrations. In addition, this method has the advantage that a compact combustion device can be provided at a low cost since it does not require a generally high-grade fuel pump or fuel injection valve such as a fuel injection type.

[Problem to be solved by the invention]

The above combustion device is small and lightweight, that is, it has a large amount of combustion per unit volume (or weight) of the device, or a large calorific value of the fuel per unit volume ('f: or Wit), and It is desired to be able to burn any liquid fuel. However, in the above-mentioned combustion device, even if the amount of fuel is increased, it is not possible to burn the fuel indefinitely, and the vaporized material 21 cannot be vaporized at certain mass sales. In other words, since the liquid fuel cannot be vaporized more than the amount of heat received by the vaporized body due to radiation and convection E, the liquid fuel that cannot be vaporized falls down from the bottom surface of the vaporized body 2 as droplets, If installed horizontally, it will fall down. At this time, a certain amount of liquid fuel can be vaporized due to heat transfer, etc., but the liquid fuel that is not completely vaporized flows into the air preheating chamber from the air distribution hole 4 on the lower side of the vaporizer 2, and eventually the flange surface of the motor 18 Raw liquid fuel may flow out from the combustion chamber 6, etc.
The liquid fuel that remains after being blown away may lower the temperature of the heat exchanger inner wall 8 with the heat of vaporization, or the gas vaporized in the combustion chamber may not burn in the normal position (near the exit of the combustion chamber or in the exhaust pipe). etc.), resulting in a decrease in efficiency and creating a dangerous situation.

In addition, when selecting fuel, for example, kerosene or diesel oil.

Comparing aviation fuel gasoline, etc. with methanol, which has recently begun to be widely used industrially, the calorific value of kerosene, diesel oil, aviation fuel, etc. is approximately 10,000 to 10,500 Ca4/g.
r, whereas that of methanol is 4760cr, and in order to obtain the same calorific value, methanol must be burned in more than twice the amount as light oil. Furthermore, when comparing the heat of vaporization of the two, taking light oil as an example, although there are various types, the average is about 90 cd7gr, whereas methanol requires 263 cdygr. This means that in order to burn methanol and obtain the same calorific value as light oil, the vaporization heat required by the vaporized substance is
x-=6.13. In other words, in the case of methanol combustion, the vaporized substance must give 6 times the amount of heat to the liquid fuel, otherwise a part of the liquid fuel will not vaporize, and as mentioned above, the liquid may drip from the motor flange surface or burn at the normal position. There is a problem in that this is not carried out and a situation such as performance deterioration occurs.

Furthermore, the rated specifications of a combustion device are determined from both the amount of combustion and the fuel, but the rated specifications are determined with safety in mind, so the size is larger than necessary.

Therefore, a combustion device that burns methanol has a vaporization capacity that is about six times greater than that of light oil, etc., and there is a problem that it cannot be made into a small and inexpensive device, which is the characteristic of this method.

An object of the present invention is to provide a liquid fuel combustion device that has high combustion capacity and combustion efficiency and can be downsized by promoting vaporization of liquid fuel.

[Means to solve the problem]

In order to solve the above problems, the present invention provides a combustion apparatus in which a porous vaporized body is impregnated with liquid fuel, vaporized in a combustion chamber by a heat medium generated from a combustion needle, and then combusted by combustion air. The vaporized body is provided with a heat transfer member that covers at least a portion of the vaporized body, and a heat transfer member that is connected to the heat transfer member and extends from the vaporized body to the combustion chamber.

[Effect]

By providing a heat transfer member that covers at least a portion of the vaporized body and a heat transfer member connected to the heat transfer member that extends from the vaporized body to the combustion chamber, the heat transfer member extending from the vaporized body can absorb the high temperature generated by combustion in the combustion chamber. Heat is received from the heating medium, and this heat is transferred through this heat transfer member and led to the vaporized body, and further transferred to the heat transfer member that covers the vaporized body and supplied to the vaporized body, so that the vaporized body contains liquid fuel. Sufficient heat is supplied to vaporize the fuel, so that the liquid fuel impregnated with the vapor and passing through the pores is completely vaporized and combusted.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view of a combustion device according to an embodiment of the present invention, $
FIG. 2 is a sectional view taken along line AA in FIG. 1.

In FIG. 1, FIG. 2, and FIG. 3 which will be described later, the same parts as in the conventional example shown in FIG. 4 are given the same reference numerals, and their explanations will be omitted. What is different from the conventional example in FIGS. 1 and 2 is the heat transfer plate I that covers the side surface of the combustion chamber of the vaporized body 2, and the heat transfer plate I that is connected to this and has a sufficient length to reach the middle position of the combustion chamber 6. This is because a plurality of heating rods 31 are provided. Here, heat exchanger plate I
The heat transfer rod 31 and the heat transfer rod 31 are firmly connected by welding or threaded joints, and the joints are rubbed so as not to generate thermal resistance. Since the heat transfer rod 31 receives sufficient flame from combustion, it can collect enough heat with its simple round rod-like cross-sectional shape, but if for some reason more heat is needed It is also possible to increase the surface area within a range that does not inhibit the In addition, between the heat exchanger plates.

The heat transfer rod 31 is made of copper, aluminum, or the like, which has good thermal conductivity.

With this configuration, the heat transfer rod 31 receives heat from the flame and combustion gas in the combustion chamber 6, and transfers the collected heat between the heat transfer plates. On the other hand, the liquid fuel sent from the fuel supply pipe 19 enters the vaporizer 2 from the fuel supply hole of the vaporizer 2, passes through the pores of the vaporizer, and reaches the surface of the vaporizer 2. At this time, part of the liquid fuel transfers heat to and from the surface of the heat exchanger plate (9).

The heat transferred to the heat transfer plate I or A further reaches the inside of the vaporized body through heat transfer of the fuel itself and heat transfer of the vaporizer body, and heats the liquid fuel. Heat is supplied to the liquid fuel and the vaporized body to be cooled to promote evaporation of the liquid fuel. Therefore, all of the liquid fuel sent to the vaporized body 2 is vaporized, and as a result, the liquid fuel is burnt well without producing any unburned fuel.

FIG. 3 is a sectional view of a combustion device according to a different embodiment of the invention. In Figure I, the fan 15 side surface 1 of the vaporized body 2
Attach the heat transfer plate ℃, and connect the heat transfer rod to the heat transfer plate blade and vaporizer 2.
It is connected to the heat exchanger plate 33 by passing through it. Also heat transfer 1e
34 is connected to the heat exchanger plate (9) and a part thereof is inserted inside the vaporizer 2.

With this structure, the heat received from the flame and combustion gas burned in the combustion chamber 6 by the heat transfer rods is transferred between the heat transfer plates and 31 through the heat transfer rods, and the heat is transferred to the vaporized body 2 (this heat is Also, the heat received by the heat transfer rod A is transferred between the heat transfer plates, and the heat transfer plate I
Heat is supplied to the vaporized body 2 from the vaporized body 2, and is also supplied from the heat transfer portion 34a inside the vaporized body 2. Therefore, the heat transfer surface that supplies heat to the liquid fuel in the vaporized body increases and evaporation of the liquid fuel is promoted, so that the combustion performance of the combustion device is improved. This is particularly effective when burning liquid fuel with a large latent heat of vaporization, such as methanol, when adding water to methanol and burning it, or when using a reformer to reform methanol.

In this embodiment, the heat transfer rods may also be connected to the heat transfer plates 324.

Further, in this embodiment, sufficient effects can be obtained even if the heat exchanger plates 32 are removed so that the heat exchanger plates A and 34 penetrate through the heat exchanger plates I and a portion thereof is inside the vaporizer 2. .

In the above embodiment, the heat transfer plate is attached to one side of the vaporizer 2 on the combustion chamber side, or on two sides of the combustion chamber side and the fan side, but the heat transfer plate is attached to the fan side of the vaporizer 2. Even if it is only 32, it has a sufficient effect. This is because the heat transfer rod section penetrating the vaporized body 2 and located inside the vaporized body 2 directly heats the liquid fuel in the vaporized body and transmits heat to the heat transfer plate 32 .

In the above embodiment, the heat transfer rods 31, 33, and 34 are made of a material with good thermal conductivity, but heat pipes may also be used. The heat transfer of heat pipes is 10 times higher than that of steel materials.
It has up to 100 times the capacity, and in this case, stainless steel or the like can be used as the tube material, so it is effective for combustion equipment that burns at high temperatures.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, at least a portion of a porous vaporized body made of ceramic or the like is covered with a heat transfer member, which is further connected to the heat transfer member, and extends from the vaporized body to the combustion chamber. Providing a heat transfer member (Thus, the heat of the heat medium generated by combustion in the combustion chamber is supplied to the liquid fuel in the vaporizer through the heat transfer member extending into the combustion chamber and covering the vaporizer to promote evaporation. As a result, there is no unburned fuel and the combustion capacity is improved, and combustion can be made normal and stable, resulting in higher combustion efficiency.Therefore, the combustion device can be made smaller.

It can be made lighter and less expensive. Furthermore, since there is no unburned material during combustion in the vaporized substance, there is no leakage of raw liquid fuel or flame ejection from the exhaust port, which has the effect of improving safety.

[Brief explanation of the drawing]

FIG. 81 is a sectional view of a combustion device according to an embodiment of the present invention, the second
The figures are a sectional view taken along the line AA in FIG. 1, FIG. 3 is a sectional view of a combustion device according to a different embodiment of the present invention, and FIG. 4 is a sectional view of a conventional combustion device. 1: Combustion device, 2: Vaporizer, 6: Combustion chamber, 1st order diagram

Claims (1)

[Claims] 1) In a combustion device in which a porous vaporized body is impregnated with liquid fuel, vaporized by a heat medium generated by combustion in a combustion chamber, and combusted by combustion air, heat transfer that covers at least a part of the vaporized body A combustion device comprising: a member; and a heat transfer member connected to the heat transfer member and extending from the vaporized body to the combustion chamber.