JPH0792213B2 - Ejector burner device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ejector type burner device for supplying a premixer of low-pressure fuel gas and air into a combustor or the like on which combustion pressure acts.

[Prior Art] As a combustor used in a gas turbine or the like, a proposal of a "combustion device" (Japanese Patent Publication No. 62-40612) shown in Fig. 4 is known.

This combustion device is a blower b that supplies pressurized air to the closed combustion chamber a with exhaust gas generated in the closed combustion chamber a.
In addition to driving the turbine c on the same axis as the above, an air supply fan d for supplying pressurized air to the combustion chamber a is attached to the combustion chamber a only when the device is started.

[Problems to be Solved by the Invention] That is, in the above-mentioned proposal, when starting the apparatus, the combustion air is supplied to the closed combustion chamber by the air supply fan to ensure suitable starting performance. A large combustion load is obtained by supplying compressed air by a blower when the exhaust gas has sufficient energy.

By the way, if the fuel supplied into the closed combustor is low-pressure gas such as city gas, a pressurizing device such as a pressurizing pump for increasing the pressure of the low-pressure gas to a pressure exceeding the internal pressure of the closed combustor is required. However, the pressurizing pump is expensive from the point of view of equipment, and there are problems that maintenance and management are difficult due to the complexity of the mechanism.

For this reason, there has been proposed a "heating device" (Japanese Patent Laid-Open No. 60-138320) provided with an ejector for sucking the fuel gas by using the negative suction pressure of air, but this proposal causes the fuel gas to be sucked. However, the fuel gas and air were not mixed and supplied as a premixed gas to the combustion chamber. That is, the ejector does not have a structure for improving the combustion performance of the combustor by utilizing the kinetic energy of air for mixing to generate the premixed gas.

[Means for Solving the Problems] This invention aims to solve the above problems,
An air inlet is formed in the rear part of the cylindrical burner main body and a fuel gas inlet is formed in the middle of the main body, and when the burner is started, the pressure for supplying the premixed gas, for example, the pressure in the combustor Since the fuel gas pressure causes the static pressure reduction part at the throttle part due to high speed to introduce air by introducing the air, if the internal pressure of the burner device is sufficiently high after this, the air pressure causes the static pressure drop at high speed at the throttle part. A part is made and it is configured to inhale the fuel gas contrary to the above. That is,
It is constructed so as to significantly improve the drive characteristics of the burner device.

[Operation] When a fuel gas having a constant pressure is supplied to the fuel gas inlet of the burner body, the suction negative pressure of the fuel gas sucks the air upstream of the throttle into the mix chamber. On the contrary, when the air pressure becomes sufficiently high, the air supplied from the air introduction port enters the mix chamber through the restrictor,
The fuel gas is sucked into the mix chamber from the fuel gas inlet by negative suction pressure of air.

By the way, the air passing through the throttle portion naturally enters the mix chamber in a turbulent state, so that the fuel gas and the air are well mixed in the mix chamber, and a premixed gas having a good ignitability is obtained. The generated premixed gas is ejected from the nozzle of the burner body into the combustor or the like.

[Embodiment] A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

First, a combustor according to the present invention will be described with reference to FIG. 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 for supplying combustion air.

A turbine 5 of a supercharger 4 is provided 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. Is provided, and an auxiliary combustor 6 for generating higher temperature exhaust gas is interposed.

On the other hand, in the air supply passage 3, on the upstream side thereof, the turbine 5
And a blower 7 which is coaxially connected to the blower 7. The blower 7 supplies combustion air that is pressurized and heated into the closed combustor 1 in accordance with the rotation of the turbine 5. To do. By the way, to the air supply passage 3 downstream of the blower 7, there is connected an air supply bypass passage 8 for supplying the fresh combustion air that has been pressurized to the auxiliary combustor 6 and has been raised in temperature. 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 a higher temperature combustion gas by supplying fresh combustion air containing a large amount of oxygen in the auxiliary combustion chamber.

The air supply bypass passage 8 and the exhaust bypass passage 9 are
The air supply bypass passage 8 is formed so as to be opened and closed by electromagnetic on-off valves 10 and 11, respectively, and has a heat exchanger 12 that exchanges heat with the lubricating oil from the supercharger 4 to cool the lubricating oil. The exhaust bypass passage 9 has a heat exchanger 13 that heats the lubricating oil by exchanging heat with the lubricating oil supplied to the supercharger 4. However, the solenoid on-off valves 10 and 11 are configured to maintain the temperature of the lubricating oil at a constant temperature in each opening / closing operation, and one of the solenoid on-off valves 10 is used when the auxiliary combustor 6 burns. It is configured to open and close the other electromagnetic on-off valve 11. That is, controller (CPU etc.)
Alternatively, the change-over switch is used to control the electromagnetic on-off valves 10 and 11 so that the maintenance operation of the supercharger 4 is performed depending on the lubricating oil temperature.

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

A power generation motor 16 is attached to a drive shaft 15 of the supercharger 4 via a clutch (not shown). The power generation motor 16 is driven when the clutch is ON and the power generation motor 16 is in power generation switching. Generates power by electromagnetic induction according to the rotation of the shaft 15,
The generated electricity is supplied to the battery 17, and when the motor is switched and the clutch is turned on.
In this case, the drive shaft 15 is driven by electricity from the battery 17. For example, the clutch is turned on when starting
When the lubricating oil temperature or the exhaust gas temperature is constant, that is, the turbine 5 is driven by the exhaust gas so that the blower 7 performs the pressurizing work of the air so that the generator motor 16 is switched to the motor position. Is designed to switch the generator motor 16 to the power generation position. In these controls, a controller (CPU or the like) that controls in response to inputs of lubricating oil temperature, atmospheric temperature, and exhaust temperature, or the solenoid opening / closing valve 10,
Try to use the 11 contacts.

Now, in the embodiment, the sealed combustor 1 and the auxiliary combustor 6 have a burner device configured as shown in FIG.
30 are installed respectively.

The burner device 30 has a cylinder-shaped burner main body 31 and one end of a supercharged air passage 3 or an intake bypass passage 8 formed by branching the air supply passage 3 downstream of the blower 7 at one end thereof. A flange 33 having an inlet 32 is integrally provided, and the other end of the burner body 31 is closed by a flange 35 having an injection port 34 for ejecting the premixed gas into each of the combustors 1 and 6. Formed.

That is, the burner body 31 having the flanges 33 and 35 has a series of fluid passages 36 in the burner body 31 that reach the above-mentioned combustors 1 and 6.
To form a section.

Further, the burner body 31 is formed with a throttle portion 37 for increasing the flow velocity of the supply air in the middle of the flow direction. In the embodiment, the throttle portion 37 is formed by gradually gradually reducing the diameter of the portion of the burner body 31 along the flow direction in the radial direction.

On the other hand, the downstream side of the narrowed portion 37 of the burner body 31 is gradually and radially expanded outward in the flow direction. That is,
A mix chamber 38 is formed downstream of the throttling portion 37 to restore the pressure of the supply air whose flow velocity has been increased when passing through the throttling portion 37 after passing through the throttling portion 37 and swirl in a turbulent state. A fuel gas inlet for the burner body 31 configured in this way
39 is a downstream side of the throttle portion 37, in the embodiment, the throttle portion
At least one or more portions of the supply air that has passed through 37 reach the maximum flow velocity and are opened in front of the slope. An annular member 41 surrounds the burner body 31 in which each fuel gas inlet 39 is opened along the circumferential direction, and defines a series of fuel gas chambers 43 for supplying the fuel gas to the fuel gas inlets 39. And
43 is a fuel supply pipe. However, the cross-section of the flow passage defined by the throttle portion 37 allows the air upstream of the throttle portion 39 to be sucked into the mix chamber 38 by the negative pressure of the fuel gas supplied from the fuel gas inlet 39 into the burner body 31. It is formed so as to have a cross section of a flow path that can be formed.

Therefore, the burner device 30 configured as described above,
The negative pressure of the fuel gas introduced from the fuel gas inlet 39 into the mix chamber 38 attracts the air upstream from the throttle portion 37 into the mix chamber 38, so that the supply of air into the burner body 31 is efficiently introduced. It will be possible.

On the other hand, since the introduced charge air has a constant flow velocity, on the contrary, a relationship that promotes the attraction of the fuel gas from the fuel gas inlet 39 is created. That is, the fuel gas and the supply air are effectively introduced into the mix chamber 38,
Make sure to generate the turbulence necessary to generate the premixed gas in 38.

The fuel (including low-pressure fuel gas such as city gas) forcibly sucked into the mix chamber 38 in this way is ignited by being mixed with the charge air while being stirred by the turbulent flow being sent downstream in the mix chamber 38. The premixed gas that is generated as the premixed gas having excellent performance is sucked into the combustors 1 and 6 from the injection port 34, and therefore, the good combustion is performed in the combustors 1 and 6.

By the way, when the wall surface 45 of the combustor (combustion furnace) is made of refractory material such as bricks and burns by heat radiation, a radiant flange 46 as shown in FIG. It is integrally molded. That is, the flange 46 is conically recessed toward the other flange 33 side around the shaft center portion, and the injection port 34 is opened to the side portion in the radial direction for ejecting the premixed air toward the inside 47 of the wall. The radiant flange 45 is formed. In order to prevent backfire in the mix chamber 38, the ratio (d / l) of the diameter d and the length l of the injection port 34
It is a matter of course to properly determine

When the secondary air is sucked into each of the combustors 1 and 6, an outer cylinder (not shown) that divides the flow path of the secondary air is surrounded on the outer peripheral surface 44 of the burner body 31. The outer cylinder may be fixed to each of the combustors 1 and 6 described above.
However, in this case, the burner body 31, which is the inner cylinder, is
It is a matter of course that both ends of 31 are supported and fixed by the outer cylinder, or each end of the burner body 31 is supported by the outer cylinder or each of the combustors 1 and 6, respectively.
It is a matter of course that the secondary air amount is adjusted on either the inflow side or the outflow side.

[Effects of the Invention] As is clear from the above description, according to the present invention, the following effects are exhibited.

An air inlet is formed in the rear part of the cylindrical burner body, and a fuel gas inlet is formed on the way, and upstream of the inlet,
The negative pressure of the air sucks the fuel gas from the fuel gas inlet, and the negative pressure of the fuel gas sucks the air from the air inlet to form a throttle portion, and the fuel gas sucked downstream and the air sucked in the flow direction. Since a mix chamber for generating a premixed gas by mixing with the above is formed, and an injection port for ejecting the premixed gas from the mix chamber is formed in the front part, even a low pressure fuel gas such as city gas can be formed with a simple structure. It can be easily and continuously supplied as a premixed gas into the closed combustor where the combustion pressure acts.

[Brief description of drawings]

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, and FIG. 3 is a partial sectional view showing a radiant flange. Four
The figure is a schematic view showing a combustion apparatus as related art. In the figure, 31 is a burner body, 32 is an air inlet, 37 is a throttle part,
38 is a mix chamber and 39 is a fuel gas inlet.

Claims (1)

[Claims] 1. A fuel gas introduction port is formed by forming an air introduction port at a rear portion of a cylindrical burner body and a fuel gas introduction port in the middle of the burner body. Form a throttle part that sucks the fuel gas from the air and sucks the air from the air introduction port by the static pressure decrease due to the high speed of the fuel gas, and premixes by mixing the fuel gas and the air sucked downstream in the middle of the flow direction. An ejector-type burner device characterized in that a mix chamber for generating air is formed and an injection port for ejecting premixed air from the mix chamber is formed in a front portion.