JPS5995313A - Atomizing method of solid fuel in state of slurry and its device - Google Patents

Abstract

PURPOSE:To improve burning efficiency without increasing auxiliary motive force, by a method wherein a slurried solid state fuel being obtained by boosting and heating up to a temperature close to that of saturated vapor of the solvent to correspond with the boosted pressure, is introduced to a reduced pressure region, flushed, and a pressurized atomized gas is made to act thereon. CONSTITUTION:A throttle 9 is provided at a part directly before connection with atomized gas of a fuel duct 3 and an air-fuel mixture duct 5 is opened in a fan-shape state in a direction of a fire furnace. Although pressure of CMM (slurried fuel) is boosted all the more and at the same time the temperature of the same is lower than that of a saturated steam corresponding to boosted pressure, the temperature is raised close to that of the saturated steam. The CMM1 whose temperature is raised and pressure is boosted is led to the air-fuel mixture duct 5 through the throttle 9. The CMM1 is turned into a decompressed state after it has been passed through the restrictor 9a, flush phenomenon is generated at a stretch, atomization is started and atomized further by atomized gas 2 to be supplied from an atomized gas duct 4. In the meanwhile, as for the fan-shaped opening part 10, as the flush phenomenon is performed continuously along its flowing direction and a solvent is expanded according to the flush phenomenon, pressure of the atomized gas 2 becomes in excess of a critical pressure ratio and the flow is accelerated and decompressed by the opening part 10. Atomized particles 7A, consequently, are made small microscopically further and injected in a fire furnace direction 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for sensitizing slurry solid fuel, and more particularly to an atomizer for slurry solid fuel suitable for improving the fog characteristics of solid fuel and improving combustion efficiency. It is.

In response to the limited availability of liquid fuels, solid fuels such as coal, which have large reserves, are being looked at. As is well known, solid fuels are more difficult to store and link than liquid fuels, so methods of slurrying them with a solvent before combustion are being explored.

Representative examples of 171J include slurry fuel made by mixing pulverized coal with fuel oil (hereinafter referred to as COM) and slurry fuel mixed with water (hereinafter referred to as CWM), but in particular CWh/I This is the type of fuel that is being looked at most closely in the future because it does not dispense fuel oil.

In the conventional CWM fuel fj8 method, 90 WM is extracted from a slurry fuel tank using a slurry pump, is pumped, and is atomized using pressurized atomization gas such as air or steam, and then combusted. At this time, the CWM is slightly heated in the middle of the pressure-feeding piping, but this is only for the purpose of reducing the viscosity for handling reasons, and the temperature is as low as 100°C or less. ” However, such conventional combustion method has the following drawbacks. The first drawback is that the atomization state of CWM is poor and the combustion efficiency is low. This is because the temperature of CwM is low. This is thought to be due to the fact that the atomization conditions are still insufficient, and the atomized particles form multiple aggregates due to the surface tension of the water, increasing the apparent particle size. In order to improve the atomization characteristics, the amount of quenching of the pressurized air and steam increases.This results in an increase in the power of auxiliary machinery, which causes a decrease in plant efficiency.The present invention The object of the present invention is to provide a method and device for atomizing slurry solid fuel that eliminates the drawbacks of the prior art described above and can improve combustion efficiency without increasing auxiliary power.

In order to achieve the above object, the present invention raises the pressure of slurry solid fuel and raises the temperature to a temperature that is lower than but close to the saturated vapor temperature of the solvent corresponding to the increased pressure,
The slurry-formed solid fuel thus obtained is introduced into a reduced pressure area to be flashed, and the flashed material is subjected to a pressurized atomizing gas.

In the present invention, the solvent (dispersion medium) applied to slurrying the solid fuel is not limited in time as long as the object of the present invention is achieved, but generally water, alcohol, fuel oil, etc. are widely suitable. Pressurization of the slurry solid fuel may be increased by any applicable method, but it is more effectively achieved by using the apparatus of the present invention in which a constriction section is provided in the pumping passage for the slurry solid fuel. By providing the constricted portion, the passage after the constricted portion naturally becomes a pressure-reduced area. It is preferable that the reduced pressure region has a structure that opens in a widening manner toward the furnace.

The pressurized atomizing gas that is applied to the flashed slurry solid fuel in the reduced pressure area is not particularly limited as long as it has an atomizing effect, but air or steam that is easily available and has an excellent atomizing effect may be used. Particularly preferred.

Generally, the Y-jut method or the swirling flow method is suitable for applying the atomizing gas, but the method is not limited thereto.

According to the present invention, the first atomization based on the slurry solid fuel itself is performed by the flash during decompression warfare, and then the second atomization based on the atomization gas is performed, so that the solid fuel In addition to achieving good atomization that prevents agglomeration of fuel particles, it is also possible to reduce the effectiveness of the auxiliary equipment because a small amount of atomization gas is required.

Hereinafter, the present invention will be explained in more detail with reference to embodiments shown in the drawings.

FIG. 1 shows a conventional atomizer according to a comparative example of the present invention. ) 3, a pressurized atomized gas passage 4 provided outside the fuel passage 3 and communicating therewith, and a mixing passage 5 for slurry solid fuel and atomized gas provided after the communication portion. It mainly consists of

In the first aspect of the above configuration, the slurry is extracted from the fuel tank with a slurry pump (both not shown) and pumped,
The CWMI, which is an example of a slurry solid fuel heated to 100° C. or lower, is passed through the fuel passage 3, mixed with the atomized gas 2 flowing in the atomized gas passage 4, and then accelerated. The atomized particles 7 form the opening at the tip of the furnace and move towards the furnace direction 8.
is injected and burned. However, the above-mentioned characteristics during atomization are not sufficient, and the atomized particles are aggregates of multiple solid fuel particles, and the combustion efficiency is not good. Although it can be improved to some extent by increasing the power, in this case, it is not preferable in terms of operating costs because it requires an increase in the power of the auxiliary equipment.

FIG. 2 shows an atomizer according to an embodiment of the present invention. This device has the same structure as the device shown in FIG. 1, except that a throttle 9 is provided in the fuel passage 3 just before the atomized gas communicates with the fuel passage 3, and a structure 10 is adopted in which the mixing passage 5 is opened in a diverging shape toward the furnace. It is.

In the apparatus configured as described above, the pressure of the CWM is further increased by the throttle 9, but at the same time, the temperature is increased to a temperature that is lower than, but close to, the saturated steam temperature of water corresponding to the increased pressure. The temperature of the upper air is generally preferably raised by a slurry fuel heater 15 provided between the slurry fuel flow meter 14 and the fuel nozzle (main body) 6, as shown in FIG. In addition, in FIG. 3, 11 is a slurry fuel tank, 12 is a slurry fuel filter provided downstream of the slurry fuel tank 11, and 13 is a slurry provided between the slurry fuel filter 13 and the slurry fuel flow meter 14. It's a fuel pump. The CWML, which has been heated and pressurized in this way, is then guided through the throttle 9 to the mixing passage 5, but after passing through the throttle 9, it is in a reduced pressure state, causing a flash phenomenon and atomization. Start. Thereafter, it is further atomized by the atomizing gas 2 supplied from the atomizing gas passage 4.

On the other hand, in the diverging opening 10, the above-mentioned flash phenomenon occurs continuously in the flow direction. In response to this, the solvent expands, so that the pressure of the known atomizing gas 2 reaches a critical pressure ratio. As a result, the wide end opening 1
0 will accelerate the flow and reduce the pressure. That is, as the slurry solid fuel is depressurized by the 1° diverging opening, an effective flash phenomenon occurs, and as a result, the atomized particles 7A are further refined and injected toward the furnace direction 8.

Next, FIGS. 4 and 5 show a Y-jet type atomizer according to an embodiment of the pond according to the present invention. A certain steam 2 passage (atomized gas passage) 4A and a slurry solid fuel 1 passage (fuel passage) 3A provided on the outer side.
, a throttle #) 9 provided immediately before the atomized gas communication of the fuel passage 3A, and a slurry solid fuel and steam mixing passage 5A provided after the communication part.

The mixing passage 5A consists of eight pieces, all of which have the same diameter structure 10A without opening in the direction of the furnace.
It becomes.

Even in the Y-jet type atomizer having such a configuration, CWM atomization can be performed satisfactorily in the same manner as in the case shown in FIG.

In each of the above examples, C was mainly used as the slurry solid fuel.
Although WM is used, the present invention is of course not limited to this, and for example, solid fuel slurried with a solvent such as alcohol or fuel oil can also be used in 1a.

As described above, according to the present invention, the slurry solid fuel whose temperature and pressure have been raised is flashed in a reduced pressure region, and the pressurized atomizing gas is applied to the slurry solid fuel, thereby creating a primary fog based on the slurry solid fuel itself. secondary atomization with pressurized atomization gas, thereby achieving a higher atomization rate and improving combustion efficiency. It is possible to reduce the auxiliary force.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing a conventional atomizer, FIG. 2 is a side sectional view of an atomizer according to an embodiment of the present invention, and FIG. 3 is a supply of slurry solid fuel according to an embodiment of the present invention. A system diagram illustrating the method, FIG. 4 is a side sectional view of an atomizer according to another embodiment of the present invention, and FIG. 5 is a diagram oriented toward the direction of FIG. 4. 1... Slurry solid fuel, 2... Atomized gas, 3.
3A...fuel passage, 4.4A...atomization gas passage, 5
．． 5A...Mixing passage, 7.7A...Atomized particles, 9.
... Throttle, 10... Diverging opening, 10A... Opening, 15... Slurry fuel heater. Agent Patent Attorney Takenaga Kawakita

Claims (3)

[Claims] (1) While increasing the pressure of the slurry solid fuel, the temperature is raised to a temperature that is lower than but close to the saturated vapor temperature of the solvent corresponding to the increased pressure, and the slurry solid fuel thus obtained is led to a reduced pressure area and flashed. 1. A method for atomizing slurry solid fuel, which comprises: (2) In an atomizer equipped with a slurry-formed solid fuel pressure-feeding passage and a pressurized atomized gas passage communicating with the passage, the slurry-formed solid-fuel pressure-feeding passage has a throttle structure just before the continuous connection. A device for quaternizing slurry solid fuel. (3) A sensitizing device for slurry solid fuel according to claim 2, characterized in that a reduced pressure atomization chamber that opens in a diverging manner toward the furnace is provided after the communication portion of the slurry solid fuel pumping passage. .