JP2005291606A - Hydrogen gas combustor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent NOx, odor specific to oils, and flue gases from occurring and also effectively utilize combustion heat by simultaneously burning liquid fossil fuels and hydrogen gas. <P>SOLUTION: This hydrogen gas combustor comprises a liquid fuel injection nozzle 2 mixing the liquid fossil fuels such as a kerosene, a heavy oil, and a light oil with air and injecting the mixed fuel and a hydrogen gas injection nozzle 3 mixing hydrogen gas with oxygen and injecting the mixed hydrogen gas. The fuel injected from the liquid fuel injection nozzle 2 is burned to form a flame, and the mixed hydrogen gas is injected, for burning, from the hydrogen gas injection nozzle 3 toward the flame. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hydrogen gas combustor that simultaneously burns liquid fossil fuel and hydrogen gas.

Generally, plant facilities, factories, large buildings, and commercial facilities are equipped with hot water supply facilities that use heavy oil, kerosene, gas, etc. as heat sources, and heat the water with kerosene boilers, gas boilers, etc. It is configured to generate water.
The steam generated from the hot water boiler is also used as a power source for working in facilities, for heating, for general heating, or for driving a prime mover such as a steam turbine.
As combustion methods of these boilers, diffusion combustion in which fuel and air are supplied from different jet nozzles and burned while being mixed in a combustion chamber, and premixed combustion in which fuel and air are mixed and then burned are employed.
In diffusion combustion, since fuel and air in the combustion chamber are not uniformly mixed and there is always a region where the air ratio is lean, it is generally difficult to reduce NOx.
On the other hand, in the premixed combustion, the fuel and air are sufficiently mixed, so the reaction region of combustion can be reduced, the flame can be shortened, and the combustion can be performed at a higher load than before. have. The use of the fuel lean premixed combustion method has the advantage that the amount of NOx emissions is reduced compared to diffusion combustion.
A technique described in Japanese Patent Application Laid-Open No. 5-106806 is known as a technique related to such a combustor that reduces NOx by premixed combustion.
JP-A-5-106806

However, since the technology described in Japanese Patent Laid-Open No. 5-106806 is configured to use only liquid fossil fuels such as naphtha, gasoline, kerosene, light oil, heavy oil, alcohol, etc., it can be said that NOx discharged is reduced. The level is limited, and the generation of a considerable amount of NOx is inevitable.
Combustors using hydrogen gas have been developed as a combustion method that completely eliminates these NOx. However, since hydrogen gas has a high ignition speed and the flame is linear, the flame is concentrated locally, It was difficult to conduct heat, and there was a problem in heat exchange.
The present invention has been made to solve the conventional problems, and the object of the present invention is to simultaneously burn liquid fossil fuel and hydrogen gas, thereby reducing NOx, oil-specific odor, and flue gas. An object of the present invention is to provide a hydrogen gas combustor that prevents generation and uses combustion heat efficiently.

  In the hydrogen gas combustor according to claim 1, liquid fossil fuel such as kerosene, heavy oil, light oil or the like is mixed with air, a liquid fuel injection nozzle for injecting the mixed fuel, hydrogen gas and oxygen are mixed, and the mixed hydrogen A hydrogen gas injection nozzle that injects gas, and forms a flame by burning the fuel injected from the liquid fuel injection nozzle, and a configuration in which mixed hydrogen gas is injected and burned from the hydrogen gas injection nozzle toward the flame .

  The hydrogen gas combustor according to claim 2 is the hydrogen gas combustor according to claim 1, wherein the combustion cylinder is arranged in a horizontal direction, a liquid fuel injection nozzle is arranged horizontally along the combustion cylinder, and the liquid The mixed hydrogen gas is jetted obliquely downward from above the liquid fuel injection nozzle so as to intersect the fuel injected from the fuel injection nozzle.

  The hydrogen gas combustor according to claim 3 is the hydrogen gas combustor according to claim 1 or 2, wherein the combustion cylinder is disposed in a state of being immersed in a series of water tanks, and the combustion cylinder is located slightly below the water tank. It is characterized by having been arranged in.

In the hydrogen gas combustor according to claim 1, since the liquid fossil fuel and the hydrogen gas are combusted at the same time, the combustion of the hydrogen gas assists the combustion of the liquid fossil fuel, and the oily odor of the exhaust gas due to incomplete combustion, Reduce smoke emissions.
In addition, the combustion of hydrogen gas is linear, but by burning with liquid fossil fuel, the flame spreads in the combustion furnace, heats the entire furnace, and improves heat exchange.
Furthermore, the amount of generated heat is increased by the combustion of hydrogen gas, and the flame length and the heating furnace can be secured horizontally long by the explosive force of the hydrogen gas, thereby ensuring a wide heat exchange area.

In the hydrogen gas combustor according to the second aspect, since the direction of the combustion cylinder and the nozzle is arranged in the horizontal direction, there is no possibility that foreign matters in the furnace are clogged in the nozzle.
In addition, since the hydrogen gas is injected obliquely downward from above the liquid fuel injection nozzle, the hydrogen gas combustion assists the combustion of the liquid fossil fuel, and they cooperate to exert a combustion effect. .

In the hydrogen gas combustor according to the third aspect, since the combustion cylinder is disposed in a state of being immersed in a series of water tanks, water can be heated using the heat of the entire periphery of the combustion cylinder.
Further, since the combustion cylinder is disposed slightly below the water tank, a large amount of water is disposed above the water tank, and high-temperature water can be obtained sequentially from the top of the tank.
In addition, since the entire outside of the combustion cylinder is in contact with water, excessive combustion in the combustion furnace can be protected.

  Hereinafter, the best mode for realizing the hydrogen gas combustor of the present invention will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the hydrogen gas combustor of the present invention includes a cylindrical combustion furnace 1 (combustion cylinder) extending in the horizontal direction and a liquid combustion injection nozzle 2 inserted from the base end side of the combustion furnace 1. Similarly, a hydrogen gas injection nozzle 3 inserted from the base end side of the combustion furnace 1 and juxtaposedly inserted above the combustion gas injection nozzle, an exhaust port 4 formed at the tip of the combustion furnace 1, and a combustion A water tank 5 surrounding the furnace 1 is a main component.

A primary combustion chamber 6 is disposed at the base of the combustion furnace 1 and has a heat-resistant structure by a castable mixture of refractory crushed stone and a binder such as alumina hydraulic cement.
The outer diameter of the primary combustion chamber is 420 mm, the castable thickness is about 60 mm, and the length is 500 mm.
The secondary combustion chamber 7 following the primary combustion chamber 6 is made of a cylindrical heat-resistant metal having an inner diameter of 420 mm and a length of 1230 mm. The portion of the secondary combustion chamber 7 is disposed in a state immersed in the water tank 5.
In the primary combustion chamber 6, the fuel injected from the nozzles 2 and 3 is ignited. In the secondary combustion chamber 7, the flame spreads and the water tank 5 is heated.

The water tank 5 has a capacity for storing 450 liters of water, an inlet 8 and a thermometer port 9 are disposed above the tank, and a drain 10 is disposed below the tank. Hot water is accumulated in the tank 5 and delivered to various places through a circulation device.
Further, as shown in the end view of FIG. 2, the water tank is formed in a cylindrical shape, and the combustion furnace 1 is disposed on the lower side of the cylindrical tank 5. Accordingly, a larger water capacity on the upper side of the combustion furnace 1 is ensured than the water capacity on the lower side, and the water tank 5 is heated mainly from the upper side.

A liquid fuel injection nozzle 2 is inserted horizontally in the center of the base of the primary combustion chamber 6, and liquid fuel is injected from the nozzle 2 to the center of the combustion furnace 1.
As these liquid fuels, liquid fossil fuels such as heavy oil, kerosene, and light oil can be used. After the liquid fuel is atomized, it is mixed with air and injected under pressure.

The hydrogen gas injection nozzle 3 is inserted obliquely downward from the upper side of the liquid fuel injection nozzle 2, and the outlet of the hydrogen gas injection nozzle 3 is located at the root portion of the flame from the liquid fuel injection nozzle.
Brown gas is injected from the hydrogen gas injection nozzle 3, contacts the injection flame from the liquid fuel injection nozzle 3, and burns together.

  Here, the brown gas is a gas obtained by uniformly mixing hydrogen and oxygen gas so that the molar ratio of hydrogen and oxygen is 2: 1. The flame generated by the combustion of the brown gas has a property that the temperature around it is as high as 2000 to 2500 ° C. in the flame, and the temperature rapidly decreases as the temperature is further away. Brownian gas becomes water vapor after combustion.

Next, the operation of the hydrogen gas combustor of the present invention will be described.
Liquid fossil fuel such as kerosene, heavy oil, and light oil is atomized, mixed with air, and injected from the liquid fuel injection nozzle 2 under pressure. Simultaneously with the injection, a flame is formed by an ignition device.
Next, brown gas (hydrogen gas) is injected from the hydrogen gas injection nozzle 3. Since the hydrogen gas injection nozzle 3 is injected from above the liquid fuel injection nozzle 2 so as to cross the injected fuel at a gentle angle, the hydrogen gas injection nozzle 3 comes into contact with the jet portion of the liquid fuel flame and burns together.
The hydrogen gas generates high heat by combustion and assists the combustion of liquid fuel. Moreover, although combustion of hydrogen gas is linear, a flame spreads in a furnace by contact with liquid fuel, and the water tank in contact with the furnace is heated as a whole.

Next, FIG. 3 is a graph showing changes in temperature when a water tank is heated using heavy oil according to a conventional example as fuel.
In FIG. 3, it takes 1 hour and 29 minutes for the boiler (0.55 t tank) to reach the hot water temperature of 100 ° C., and 3 hours 30 minutes for the hot water storage tank (0.95 t tank) to reach the hot water temperature of 90 ° C. It takes minutes.
On the other hand, FIG. 4 is a graph showing the temperature change when the water tank is heated by the hydrogen gas combustor of the present invention.
The shape and other conditions of the fuel furnace and water tank were the same as those of the combustion furnace of FIG.
In FIG. 4, it takes 1 hour 07 minutes for the boiler (0.55 t tank) to reach a hot water temperature of 100 ° C., and 2 hours 46 minutes for the hot water storage tank (0.95 t tank) to reach a hot water temperature of 90 ° C. It takes minutes.
Therefore, compared with FIG. 3, when the hydrogen gas combustor of FIG. 4 is used, it is confirmed that the heating time is much shortened.

  Next, FIGS. 5 to 10 are graphs showing changes in the temperature of the water tank when kerosene is used alone and when kerosene / brown gas is used using the hydrogen gas combustor of the present invention. It is.

(1) FIG. 5 (diameter of liquid fuel injection nozzle: 1.5 mm, insertion length: 100 mm)
The temperature rise change of the water in a tank at the time of injecting and burning kerosene from a liquid fuel injection nozzle is shown. It takes 53 minutes for the water in the tank to reach 90 ° C.
The consumed fuel is 10.5 liters (198 cc / min).
(2) FIG. 6 (Hydrogen gas injection nozzle insertion length: 50 mm)
The change in the temperature rise of the water in the tank when kerosene is injected from the liquid fuel injection nozzle and brown gas is injected from the hydrogen gas injection nozzle and burned by the hydrogen gas combustor of the present invention is shown. It takes 46 minutes for the water in the tank to reach 90 ° C.
The consumed fuel is 10 liters (217 cc / min).
(3) FIG. 7 (hydrogen gas injection nozzle insertion length: 15 mm)
Similarly to the above, the temperature rise change of the water in the tank when kerosene is injected from the liquid fuel injection nozzle and Brown gas is injected from the hydrogen gas injection nozzle and burned is shown. It takes 33 minutes for the water in the tank to reach 90 ° C. The experimental results are the best.
The consumed fuel is 6.6 liters (200 cc / min).
(4) FIG. 8 (hydrogen gas injection nozzle insertion length: 300 mm)
Similarly to the above, the temperature rise change of the water in the tank when kerosene is injected from the liquid fuel injection nozzle and Brown gas is injected from the hydrogen gas injection nozzle and burned is shown. It takes 36 minutes for the water in the tank to reach 91 ° C.
The consumed fuel is 7.2 liters (200 cc / min).
(5) FIG. 9 (Hydrogen gas injection nozzle insertion length: 150 mm)
Similarly to the above, the temperature rise change of the water in the tank when kerosene is injected from the liquid fuel injection nozzle and Brown gas is injected from the hydrogen gas injection nozzle and burned is shown. It takes 39 minutes for the water in the tank to reach 90.1 ° C.
The consumed fuel is 7.7 liters (197 cc / min).
(6) FIG. 10 (hydrogen gas injection nozzle insertion length: 80 mm)
Similarly to the above, the temperature rise change of the water in the tank when kerosene is injected from the liquid fuel injection nozzle and Brown gas is injected from the hydrogen gas injection nozzle and burned is shown. It takes 41 minutes for the water in the tank to reach 100 ° C.
The consumed fuel is 8.3 liters (202 cc / min).

In (1) above, the exhaust outlet temperature is about 600 ° C., whereas the exhaust outlet temperature in (2) is 800 ° C., and the exhaust outlet temperatures in (3) to (6) are 900 ° C. or higher. It is completely burned and clean exhaust.
In addition, as compared with (1), all of (2) to (6) have a shorter time to boiling and fuel consumption is reduced. In particular, it was confirmed that the experimental result of (3) was the shortest time (33 minutes), the hot water temperature reached 90 ° C., and the fuel consumption of Brown gas was the smallest.
On average, energy saving time is about 28%, and energy saving fuel is 2.9 liters and 27%. This is due to the complete combustion of the brown gas. If heavy oil is used instead of kerosene, it is certain that the energy saving is 30% or more in view of oil quality.
Overall, when used as an auxiliary fuel, fossil fuel is almost completely combusted, clean exhaust, soot (carbon) is reduced, and energy is saved from the standpoint of maintenance.

As mentioned above, although the Example of this invention was described, a concrete structure is not limited to the said Example, Even if there is a design change etc. of the range which does not deviate from the summary of invention, it is contained in this invention.
For example, the shapes and insertion positions of the liquid fuel injection nozzle and the hydrogen gas injection nozzle are appropriately set according to the combustion furnace mechanism and the like.

It is a schematic sectional drawing of a hydrogen gas combustor. It is an AA end view. It is a figure which shows the temperature rise change which heated water with the liquid fossil fuel. It is a figure which shows the temperature rise change which heated water with the hydrogen gas combustor of this invention. It is a figure which shows the temperature rise change which heated water more with kerosene. It is a figure which shows the temperature rise change which mixedly burned with the hydrogen gas combustor and heated water. It is a figure which shows the temperature rise change which mixedly burned with the hydrogen gas combustor and heated water. It is a figure which shows the temperature rise change which mixedly burned with the hydrogen gas combustor and heated water. It is a figure which shows the temperature rise change which mixedly burned with the hydrogen gas combustor and heated water. It is a figure which shows the temperature rise change which mixedly burned with the hydrogen gas combustor and heated water.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Combustion furnace 2 Liquid fuel injection nozzle 3 Hydrogen gas injection nozzle 4 Exhaust port 5 Water tank 6 Primary combustion chamber 7 Secondary combustion chamber 8 Inlet 9 Thermometer port 10 Drain

Claims (3)

Liquid fuel injection nozzle that mixes liquid fossil fuel such as kerosene, heavy oil, light oil and air and injects the mixed fuel;
A hydrogen gas injection nozzle that mixes hydrogen gas and oxygen and injects the mixed hydrogen gas;
A hydrogen gas combustor configured to burn a fuel injected from the liquid fuel injection nozzle to form a flame and to inject and burn mixed hydrogen gas from the hydrogen gas injection nozzle toward the flame.   A combustion cylinder is arranged in a horizontal direction, a liquid fuel injection nozzle is arranged horizontally along the combustion cylinder, and diagonally from above the liquid fuel injection nozzle so as to intersect with the fuel injected from the liquid fuel injection nozzle. The hydrogen gas combustor according to claim 1, wherein the mixed hydrogen gas is injected downward.   The hydrogen gas combustor according to claim 1 or 2, wherein the combustion cylinder is disposed in a state of being immersed in a series of water tanks, and the combustion cylinder is disposed slightly below the water tank.

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