JPH01237326A - Ejector type burner - Google Patents

Abstract

PURPOSE:To improve the combustion performance in the title burner by forming a throttle part in the mid-position of a fluid passage connected to an air supply source inside a cylindrical burner main body, then sucking fuel gas under a reduced static pressure depending on a high speed flow passing through the throttle part so as to eject the fuel gas mixed with the air flow. CONSTITUTION:The burner 30 mounted in an enclosed combustion chamber of a gas turbine or the like is provided with an air introducing entrance 32 connected to the end of a supercharged air passage 3 extending from a discharge side of a blower, at one end of a cylindrical burner main body 31. The other end of the burner main body 31 is enclosed by a flange 35 having an ejection hole 34 for ejecting pre-mixture to respective combustors. A throttle part 37 is formed at a mid-position of a fluid passage 36 inside the burner main body 31. A fuel gas chamber 43 interconnected to a fuel gas chamber 43, is formed directly downstream from the throttle part 37. Then, the fuel gas is sucked by the air flow accelerated at the throttle part 37 so as to be mixed with the air flow in a mixing chamber 38.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION This invention relates to an ejector-type burner device that supplies a premixture of low-pressure fuel gas and air into a combustor or the like where combustion pressure is applied.

[Prior Art] As a combustor employed in the Gaster E, etc., a proposal for a ``combustion device'' (Japanese Patent Publication No. 40612/1983) shown in Fig. 4 is known.

This combustion device uses exhaust gas generated in a closed combustion chamber a, and a blower b that supplies pressurized air to the closed combustion chamber a.
The engine is configured to drive a turbine C coaxially with the engine, and an air supply fan d is attached to the combustion chamber a to supply pressurized air only when the apparatus is started.

[Problems to be Solved by the Invention] That is, the above proposal supplies combustion air to the closed combustion chamber with an air supply fan to ensure suitable starting performance when starting the device, and prevents air from flowing from the combustion chamber. A large combustion load is obtained by supplying pressurized air by a blower when the exhaust gas has sufficient energy.

By the way, if the fuel supplied into the sealed combustor is low-pressure gas such as city gas, a pressurizing device such as a pressurizing pump is required to boost the pressure of the low-pressure gas to a pressure that exceeds the internal pressure of the sealed combustor. However, pressurized pumps are expensive from an equipment point of view, and have problems such as difficulty in maintenance and management due to the complexity of the mechanism.

For this purpose, a "heating device" (Japanese Unexamined Patent Publication No. 60-138
No. 320), this proposal was limited to just inhaling the fuel gas, and did not mix the fuel gas and air and supply it to the combustion chamber as a premixed mixture. In other words, the ejector does not have a structure that improves the combustion performance of the combustor by utilizing the kinetic energy of air for mixing to generate a premixed mixture.

[Means for Solving the Problems] This invention aims to solve the above problems,
An air inlet is formed at the rear of the cylindrical burner body, and a fuel gas inlet is formed in the middle, so that when the burner device is started, the pressure inside the combustor, which is the target for supplying the premixture, is Since the pressure inside the burner device becomes high enough, the pressure of the fuel gas causes a high-speed static pressure drop in the constriction section, and air is introduced into the constriction section. A static pressure reduction section is created due to high speed, and the structure is configured so that fuel gas is inhaled in the opposite manner to the above. That is, the burner device is configured to significantly improve its drive characteristics.

[Function] When fuel gas at a constant pressure is supplied to the fuel gas inlet of the burner main body, the negative suction pressure of the fuel gas causes the air upstream of the throttle part to be sucked into the mix chamber. Conversely, when the air pressure becomes high enough, the air supplied from the air inlet passes through the constriction part and enters the mix chamber.
Air suction Negative pressure is used to suck fuel gas into the mix chamber from the fuel gas inlet.

Incidentally, since the air passing through the constriction naturally enters the mix chamber in a turbulent state, the fuel gas and air mix well in the mix chamber, forming a premixture with good ignitability. The generated premixture is injected into the combustor etc. from the nozzle of the burner body.

[Embodiment] A preferred embodiment of the present invention will be described below based on the accompanying drawings.

First, a combustor according to the present invention will be explained based on FIG. 2. As shown in the figure, the closed combustor 1 is connected to an exhaust passage 2 of the closed combustor 1 and an air supply passage 3 that supplies combustion air.

A turbine 5 of a supercharger 4 is disposed downstream of the exhaust passage 2, and a fuel gas is added to the exhaust gas discharged from the closed combustor 1 in the exhaust passage 2 downstream of the turbine 5. An auxiliary combustor 6 is provided to supply the exhaust gas and generate even higher temperature exhaust gas.

On the other hand, the air supply passage 3 has the turbine 5 on its upstream side.
A blower 7 connected coaxially with the turbine 5 is interposed, and the blower 7 supplies pressurized and heated combustion air into the closed combustor 1 according to the rotation of the turbine 5. do. Incidentally, an air supply bypass passage 8 is connected to the air supply passage 3 downstream of the blower 7, and supplies pressurized and heated fresh combustion air to the auxiliary combustor 6. An exhaust bypass passage 9 that bypasses the auxiliary combustor 6 is connected to the exhaust passage 2 between the auxiliary combustors 6 .

Therefore, the exhaust gas discharged from the closed combustor 1 can be discharged as even higher temperature combustion gas by being supplied with fresh combustion air containing a large amount of oxygen in the auxiliary combustion chamber.

These air supply bypass passage 8 and exhaust bypass passage 9 are
They are each formed to be opened and closed by electromagnetic on-off valves 10 and 11, and the air supply bypass passage 8 has a heat exchanger 12 that exchanges heat with the lubricating oil from the supercharger 4 to cool the lubricating oil. a heat exchanger 1 in which the exhaust bypass passage 9 heats the lubricating oil by exchanging heat with the lubricating oil supplied to the supercharger 4;
3. However, the opening and closing operations of the electromagnetic on-off valves 10 and 11 are configured to maintain the temperature of the lubricating oil at a constant temperature. is opened, and the other electromagnetic on-off valve 11 is closed. That is, the electromagnetic on-off valves 10 and 11 are mainly controlled by a controller (such as a CPU) or a changeover switch, and the maintenance operation of supercharging tJ&4 is performed depending on the lubricating oil temperature.

Next, the configuration of the assist device 25 will be explained.

A generator motor 16 is attached to the drive shaft 15 of the supercharger 4 via a clutch (not shown), and the generator motor 16 is driven when the clutch is ON and the generator motor 16 is switched to power generation. The structure is such that power is generated by electromagnetic induction according to the rotation of the shaft 15, and the generated electricity is supplied to the battery 17. At the same time, when the motor is switched and the clutch is ON, the electricity from the battery 17 is The drive shaft 15 is configured to be driven by the drive shaft 15. For example, at startup, the clutch is turned on and the generator motor 16 is switched to the motor position, so that the lubricating oil temperature or the exhaust gas temperature is constant, that is, the turbine 5 is driven with exhaust gas;
When the blower 7 has the energy to perform air pressurization work, the power generation motor 16 is switched to the power generation position. For these controls, a controller (CPU
etc.) or by using the contacts of the electromagnetic on-off valves 10 and 11.

Now, in this embodiment, a burner device 30 configured as shown in FIG. 1 is attached to the closed type combustor 1 and the auxiliary combustor 6, respectively.

This burner device 30 has a burner body 3 formed into a cylindrical shape.
1 is integrally provided with a flange 33 having an air inlet 32 to which the end of the supercharging passage 3 or the intake bypass passage 8 formed by branching the air supply passage 3 downstream of the blower 7 is connected to one end of the flange 33. The other end of the burner body 31 has a nozzle 3 for injecting the premixed gas into each of the combustors 1 and 6.
It is closed and formed with a flange 35 having a flange 4.

That is, this burner body 31 with flanges 33.35
defines a series of fluid passages 36 in the burner body 31 leading to each of the combustors 1.6.

Furthermore, the burner body 31 is formed with a constriction part 37 in the middle of the flow direction thereof to increase the flow velocity of the supplied air. In the embodiment, the throttle portion 37 is formed by sequentially reducing the diameter of the portion of the burner body 31 along the flow direction in the radial direction.

On the other hand, the diameter of the burner main body 31 downstream of the constricted portion 37 is gradually expanded radially outward along the flow direction. That is, a mix chamber 38 is defined downstream of the constriction section 37, in which the pressure of the supply air whose flow rate is increased when passing through the constriction section 37 is restored after passing through the constriction section 37, and the mix chamber 38 is made to swirl in a turbulent state. With respect to the burner body 31 configured in this manner, the fuel gas inlet 39 is located downstream of the throttle section 37, and in the embodiment, at least in the portion 40 where the supply air that has passed through the throttle section 37 reaches its maximum flow velocity. It opens at the front of the diagonal entrance with one or more facing. Reference numeral 41 denotes an annular ring which circumferentially surrounds the burner body 31 in which each fuel gas inlet 39 is opened, and defines a series of fuel gas chambers 43 for supplying fuel gas to the three fuel gas inlets. 43 is a fuel supply pipe. However, the cross section of the flow path defined by the constriction part 37 is such that the negative pressure of the fuel gas supplied from the fuel gas inlet 39 into the burner body 31 causes the passage from the constriction part 39. The flow path is formed to have a cross section that allows upstream air to be drawn into the mix chamber 38.

Therefore, the burner device 30 configured as described above attracts the air upstream from the throttle part 37 into the mix chamber 38 by the negative pressure of the fuel gas introduced into the mix chamber 38 from the fuel gas inlet 39. , burner body 3
It becomes possible to efficiently introduce air supply into the interior of the vehicle.

On the other hand, since the introduced supply air has a constant flow velocity, a relationship is created that conversely promotes the attraction of fuel gas from the fuel gas inlet 39. That is, the fuel gas and charge air are effectively introduced into the mix chamber 38 to ensure the turbulence necessary to create a premixed mixture within the mix chamber 38.

The fuel (including low-pressure fuel gas such as city gas) forcibly sucked into the mix chamber 38 in this way is mixed with the supply air while being stirred by the turbulent flow sent downstream in the mix chamber 38, and is ignited. The generated premixture becomes a premixture with excellent performance and flows from the injection port 34 to each of the above-mentioned combustors 1.
, 6, good combustion takes place within the combustor 1.6.

By the way, when the wall surface 45 of the combustor (combustion furnace) is made of a fireproof material such as brick and combustion is performed by heat radiation, a radiant-shaped flange 46 or a burner body 31 as shown in FIG. Molded in one piece. That is, the flange 46
A radiant-shaped flange is formed by making a cone-shaped recess around the shaft center toward the other flange 33 side, and opening a nozzle 34 in the radial direction to blow out the premixed gas toward the inner wall 47 side. 4
5 was formed. In addition, in order to prevent packfire within the mix chamber 38, the diameter d of the nozzle 34,
Naturally, the ratio of length p (d/Jl') can be determined appropriately.

In addition, when the secondary air is sucked into each of the combustors 1 and 6, an outer cylinder (not shown) that defines a flow path for the secondary air is provided on the outer circumferential surface 44 of the burner body 31. established in
The outer cylinder may be fixed to each of the combustors 1.6. However, in this case, the burner main body 31 serving as the inner cylinder is supported and fixed at both ends of the burner main body 31 by the outer cylinder, or each end of the burner main body 31 is supported by the outer cylinder or each combustor 1.6. It is a matter of course that the configuration is done, and furthermore, it is also natural to adjust the amount of secondary air on either the inflow or outflow side.

[Effects of the Invention] As is clear from the above explanation, the present invention exhibits the following effects.

An air inlet is formed at the rear of the cylindrical burner body, and a fuel gas inlet is formed in the middle, and upstream of the inlet,
Forms a constriction section that sucks fuel gas from the fuel gas inlet with the negative pressure of the air and sucks air from the air inlet with the negative pressure of the fuel gas, and also directs the fuel gas and air sucked downstream into the flow direction. A mix chamber is formed to generate a pre-mixture by mixing the mixture with the 12- Even if there is, it can be easily and continuously supplied as a premix into a sealed combustor where combustion pressure acts.

[Brief explanation of the drawing]

FIG. 1 is a detailed view of essential parts showing a preferred embodiment of the present invention, FIG. 2 is a schematic view of a small combustor according to the present invention, FIG. 3 is a partial cross-sectional view showing a radiant-shaped flange, and FIG. 4
The figure is a schematic diagram showing a combustion device as related technology. In the figure, 31 is a burner main body, 32 is an air inlet, 37 is a throttle part, 38 is a mix chamber, and 39 is a fuel gas inlet. Patent applicant: Taisei Kogyosho Co., Ltd.

Claims (1)

[Claims] 1. An air inlet is formed at the rear of the cylindrical burner body, and a fuel gas inlet is formed in the middle, and the fuel gas is introduced from the fuel gas inlet upstream of the inlet by static pressure reduction due to the high velocity of the air. At the same time, the fuel gas and air sucked downstream are mixed in the flow direction to form a premixture. 1. An ejector-type burner device characterized in that a mix chamber is formed in which the mixture is mixed, and a nozzle is formed in the front portion of the mix chamber to eject a premixed gas from the mix chamber.