JPH0710044Y2 - Exhaust pipe structure of gas turbine engine vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an exhaust pipe structure suitable for vehicles such as buses equipped with a gas turbine engine.

[Conventional technology]

In a vehicle equipped with a gas turbine engine, the gas turbine engine is arranged in the engine room at the rear of the vehicle, as in a vehicle equipped with a normal diesel engine. However, the structure of the exhaust pipe is very different. That is, in a normal diesel engine, the exhaust pipe is taken out from the lower part of the engine room, but in the gas turbine engine, the exhaust pipe extends vertically upward in the engine room and is taken out from the upper part of the engine room. This is because the gas turbine engine has 10 times more intake air than a normal diesel engine and does not have a cooling system using cooling water, so the temperature of exhaust gas is high. That is, since the exhaust gas is hot, it is not possible to direct the exhaust gas flow to the lower rear side of the vehicle, unlike the case of a conventional diesel engine,
Even if the exhaust pipe becomes a little longer, the exhaust gas outlet is guided to the upper side of the engine room, where it is discharged toward the rear of the vehicle to the outside of the vehicle.

[Problems to be solved by the invention] As described above, in a gas turbine engine vehicle, the exhaust gas amount is considerably higher than that of a normal diesel engine, and the exhaust gas temperature becomes higher, so the exhaust gas is discharged from the upper part of the engine room. However, the conventional technique has a problem that the temperature of the engine room is considerably higher than that of the diesel engine because no effective cooling means is provided.

This invention aims to keep the temperature of the engine room as low as possible in a gas turbine engine.

[Means for Solving the Problems]

According to this invention, an exhaust pipe that extends substantially vertically upward from a gas turbine engine provided in an engine room and is opened to the atmosphere at the upper part of the vehicle, and a double pipe is formed around the exhaust pipe. A louver, the inner end of the duct being connected to an exhaust fan, the air introduced between the inner pipe and the outer pipe of the double pipe being rotated around the inner pipe and flowing. An exhaust pipe structure is provided, which comprises:

[Action]

Ventilation gas is forcibly supplied from the exhaust fan between the exhaust pipe and the duct, and the exhaust gas passing through the exhaust pipe is forcibly cooled. The louver is driven to rotate around the inner pipe by the flow of air from the ventilation fan, and the air exchanges heat with the exhaust gas while flowing to rotate around the exhaust pipe.

〔Example〕

In FIGS. 1 and 2 showing the rear part of the gas turbine-mounted bus, 10 is a vehicle body, 12 is a passenger compartment, and the rear end of the passenger compartment 12 is partitioned by a partition plate 14. The partition plate 14 includes a horizontal ceiling portion 14-1, a first vertical portion 14-2 continuing to the ceiling portion 14-1, a second horizontal portion 14-3 continuing to the first vertical portion 14-2, Two horizontal portions 14-3 and a second vertical portion 14-4 are formed. An engine room 16 is formed in the rear part of the vehicle body 10 by the partition plate 14. Horizontal part 14-3
A gas turbine engine 18 is disposed inside the engine rum 16 below. The gas turbine engine 18 has an engine main body 18-1, an exhaust pipe 18-2 extends laterally from the engine main body 18-1, is connected to a silencer 20, and is connected to a silencer 20 from the upper portion of the vehicle to the outside of the vehicle via an exhaust pipe 22. Exhaust gas is discharged toward. That is, most of the exhaust pipe 22 is vertically arranged, the upper end 22 'is bent horizontally, and the end thereof is open to the outside of the vehicle. In FIG. 2, only the exhaust pipe 22 connected to the left side portion of the engine 18 is shown.
Although not shown, an exhaust pipe having the same structure is also provided on the right side of the engine 18. An intake pipe 21 is provided for introducing intake air into the engine 18, and intake air is introduced toward the engine 18 through openings 21-1 opening to the outside of the vehicle from both sides of the upper part of the engine room.

The exhaust pipe 22 has a double structure composed of an inner pipe 22-1 and an outer pipe 22-2, and constitutes a feature of the present invention. Exhaust pipe 22
The lower end of the inner pipe 22-1 is connected to the exhaust pipe 18-2 of the gas turbine engine via the silencer 20. Outer tube 22-
2 is arranged coaxially with the inner pipe 22-1 to form a double pipe. The lower end of the outer tube 22-2 is connected to the ventilation fan device 24. The ventilation fan device 24 is a fan housing 24-1.
And a centrifugal fan 24-2 installed in the housing 24-2
And an electric motor 24-3 connected to the rotary shaft 24-2a of the centrifugal fan 24-2, and the housing 24-1 is connected to the outer pipe 22-2 of the exhaust pipe 14 at the outlet of the centrifugal fan 24-2. To be done. Due to the rotation of the electric motor 24-3, the air in the engine room is sent as ventilation air from the housing 24-2 to the annular space 25 between the outer pipe 22-2 and the inner pipe 22-1 of the exhaust pipe. Ventilation air from the engine room 16 flows through the annular space 25 between the inner pipe 22-1 and the outer pipe 22-2, so that the inner pipe 22-
The exhaust gas flowing through the inside of No. 1 is forcibly cooled, and the temperature of the exhaust gas can be lowered. Further, as shown in FIG. 2, the ventilation fan device is provided almost directly above the gas turbine engine 18 and can directly absorb the heat generated from the gas turbine engine 18 to lower the ambient temperature in the engine room.

FIG. 3 shows louvers 26 arranged in an annular space 25 formed between the inner pipe 22-1 and the outer pipe 22-2 at two upper and lower positions of the exhaust pipe 22. The louver 26 is composed of a cylindrical body 27 which is rotatable on the outer wall surface of the inner tube 22-1, and fins 26-1 which are fixedly mounted on the cylindrical body 27 while being inclined along the axis. The inclined fan 26-1 receives the flow of ventilation gas that is pressure-fed between the double tubes 22-1 and 22-2 from the centrifugal fan 24-1, and the louver 26-1
Is rotationally biased around the axis, resulting in fan unit 24
The exhaust gas flowing inside the inner pipe 22-1 can be efficiently cooled even if the flow rate of the ventilation gas from the inside is small.

The upper end 22 'of the exhaust pipe is the tip of the outer pipe 22-2 as shown in FIG.
The fan device 22-2a is arranged so as to project from the inner pipe 22-2 and be slightly bent inward, and has passed through the annular space 25 between the inner pipe 22-1 and the outer pipe 22-2. The air in the engine room for ventilation from is guided by the flow of exhaust gas from the inner pipe 22-1 while being throttled, and the mixing action there also contributes to the effective cooling action of the exhaust gas.

FIG. 5 is a block diagram of a control circuit for driving the ventilation fan 24, which includes a microcomputer 29, and the microcomputer 29 is an exhaust pipe 18 of the gas turbine engine 18.
-2, the temperature sensor is connected to the temperature sensor 30
A signal corresponding to the temperature of the exhaust gas is obtained from 30. On the other hand, the microcomputer 29 is connected to a relay 32, and the relay 32 supplies the drive motor 24-3 of the centrifugal fan 24-2 with a power source 34.
Located in a closed circuit that connects to. A variable resistor 38 is positioned in the closed circuit, a slider 38-1 of which is connected to an actuator 40, a microcomputer 29 applies an electric signal to the actuator 40, and a slider 38 of the variable resistor 38. −
The position of 1 is controlled according to the temperature of the exhaust gas. That is,
When the temperature of the exhaust gas detected by the temperature sensor 30 is high, the microcomputer 29 sends a drive signal to the actuator 40 and causes the variable resistor 38 to increase the current so that the slider 38-1
Is controlled, and the number of rotations of the motor 24-3 increases, so that the flow rate of the ventilation gas from the fan device 24 increases. On the other hand, when the temperature of the exhaust gas detected by the temperature sensor 30 is low, the microcomputer 29 sends a drive signal to the actuator 40 to control the variable resistor 38 so that the current is reduced, and the rotation speed of the motor 24-3 is small. Therefore, the flow rate of the ventilation gas from the fan 24 decreases. By the feedback control as described above, the temperature of the exhaust gas is controlled to an appropriate temperature.

〔effect〕

According to this invention, the exhaust pipe of the gas turbine has a double pipe structure, and the louver is provided to rotate the air introduced between the inner pipe and the outer pipe of the double pipe to flow around the inner pipe. By doing so, it is possible to lengthen the route through which heat can be exchanged between the air and the inner pipe (exhaust pipe), and it is possible to achieve a sufficient cooling action with a small amount of air.

[Brief description of drawings]

FIG. 1 is a side view of the engine room at the rear of the gas turbine engine-equipped bus of the present invention. FIG. 2 is a view showing a left half portion on the rear surface of the engine room. FIG. 3 is a perspective view showing a schematic structure of louvers provided at the upper and lower ends of the double exhaust pipe. FIG. 4 is a schematic sectional view of the open end of the exhaust pipe. FIG. 5 is a block diagram of the control circuit for driving the ventilation fan. 10 ... Body, 12 ... Car interior, 16 ... Engine room, 18 ... Gas turbine engine, 22 ... Dual exhaust pipe, 22-1 ... Inner pipe, 22-
2 ... Inner tube, 24 ... Fan device, 24-1 ... Centrifugal fan, 24-
3 ... Electric motor, 26 ... Louver, 26-1 ... Inclined fin, 29
… Microcomputer, 30… Exhaust gas temperature sensor, 32
… Relays, 40… actuators.

Claims (1)

[Scope of utility model registration request] 1. An exhaust pipe extending substantially vertically upward from a gas turbine engine provided in an engine room and open to the atmosphere at the upper part of a vehicle, and an exhaust pipe arranged to form a double pipe around the exhaust pipe. A louver, the inner end of the duct being connected to an exhaust fan, and the air introduced between the inner pipe and the outer pipe of the double pipe being rotated around the inner pipe and flowing. Exhaust pipe structure characterized by doing.