JPH0344205B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a multi-cylinder diesel engine with a supercharger that supplies exhaust gas from the outlet of a supercharger to a power turbine to recover and utilize exhaust heat. (pound engine) exhaust pipe device.

(Prior Art) In FIG. 5 showing a conventional structure, 1 is an engine body, and 2 is a supercharger. The supercharger 2 includes a compressor 3 and a turbine 4. Exhaust gas is supplied to the turbine 4 from the engine body 1 via an exhaust pipe 12, and after driving the turbine 4, the exhaust gas passes through an exhaust pipe 13 to the power turbine. After driving the power turbine 5, the exhaust gas is supplied to the exhaust pipe 14.
It is then released into the atmosphere. The exhaust heat energy recovered by the power turbine 5 is returned to the engine body 1 via the power transmission device 6. 7 is an air cooler.
The exhaust pipe 12 has the highest temperature (600 to 700℃) in the exhaust system.
℃), and even if covered with asbestos or other insulating material, a considerable amount of heat is still radiated, and a considerable amount of waste heat energy is wasted into the atmosphere. Also, the temperature of the surface of the insulation material is 100 to 200 degrees Celsius, so safety precautions are required because it cannot be completely covered. Furthermore, there are two exhaust pipes 12 and 13 at the front and rear of the turbine 4, which are unfavorable from a safety point of view because they reach high temperatures.

(Objectives of the Invention) The objects of the present invention include reducing heat radiation (heat loss) from the exhaust pipe system and increasing exhaust heat recovery efficiency, simplifying the heat shield structure, and improving safety in the factory.

(Structure of the Invention) The present invention provides a multi-cylinder diesel engine with a supercharger that supplies exhaust gas from a supercharger outlet to a power turbine to recover and utilize exhaust heat. The exhaust outlet pipe is connected to the exhaust outlet branch pipe of each cylinder and runs along the cylinder row, and is covered with an exhaust outlet connecting pipe that connects the supercharger outlet and the power turbine, resulting in a double structure. This is an exhaust pipe device for a multi-cylinder diesel engine with a supercharger.

(Example) FIG. 1 is a schematic diagram showing the configuration of the present invention, in which the portion A is a double-walled exhaust pipe that functions as a heat exchanger.
That is, in A, the exhaust manifold pipe 12 and the exhaust outlet connecting pipe 13
is opposed. The upstream portion 8 of the exhaust outlet connecting pipe 13 connects the double structure exhaust pipe A and the turbine 4,
The downstream part 9 connects the power turbine 5 of the double exhaust pipe A. In FIG. 1, the same symbols as those in FIG. 5 indicate corresponding parts. Also 16,1
7 and 18 are air supply pipes, a is an intake port, 19 is a shaft connecting the turbine 4 and the compressor 3, and 20 is a flywheel.

Figure 2 is a side view showing the specific structure of the double-layered exhaust pipe A in Figure 1, with the numbers 1 to 6 in the circles in the figure.
is the cylinder number, and the first to third cylinders are branch pipe 2.
2 to the exhaust manifold pipe 10 for the first to third cylinders shown in FIG.
It is connected to the exhaust manifold pipe 11 (Fig. 4) for the fourth to sixth cylinders through the . The exhaust manifold pipes 10 and 11 are covered with an exhaust outlet connecting pipe 13 via a chamber c having an annular cross section, forming a double structure, and the inlet of the connecting pipe 13 is connected to the exhaust gas outlet of the turbine 4 via the connecting pipe 8. The outlet of the communication pipe 13 is connected to the power turbine 5 via the communication pipe 9 as described above. A portion of the exhaust manifold pipe 12 exposed from the communication pipe 13 is connected to the inlet of the turbine 4.

Exhaust gas discharged from the cylinder head of each cylinder passes through branch pipes 22 and 23 to exhaust manifold pipe 10,
Gather at 11 and 12. Normally, in the case of 6 cylinders, they are grouped into 2 groups and connected separately to the supercharger inlet with connecting pipes 10 and 1.
1. The exhaust gas that drove the turbine in the supercharger 2 is discharged to the exhaust outlet connecting pipe 8,
Power is generated (recovered) by being sent to the power turbine 5 and expanded to the atmosphere, and the power is applied to the crankshaft of the engine by the power transmission device 6.
The temperature at the turbocharger outlet section is 100 to 200 degrees Celsius lower than the inlet section b, and a certain amount of heat is transferred from the outer surface of the exhaust outlet connecting pipe 12 (10, 11) to the exhaust gas in the chamber c. A feature of the present invention is that there is no total loss.

In addition, as shown in bold lines in Figs. 2 to 4, the branch pipe 2
2, 23, turbine 4, outlet connecting pipe 8, 13,
9. The exposed parts of the power turbine 5, exhaust manifold pipe 12, etc. are covered with a heat insulating material such as asbestos to prevent heat dissipation to the outside air and for safety reasons.

(Effects of the Invention) According to the present invention, the heat dissipated from the exhaust pipe at the inlet of the supercharger is transferred to and absorbed by the exhaust gas at the exit, and by making the exhaust pipe have a double structure, heat dissipation (heat loss) from the exhaust pipe system is achieved. It is possible to reduce waste heat recovery efficiency and improve waste heat recovery efficiency. Also, the double structure makes heat shielding easier and improves the heat insulation effect. Safety is also improved due to burnout of the exhaust manifold, gas blow-through, and heat shielding at maximum temperatures.
Further, according to the present invention, the supercharger is arranged near the end of the cylinder row, and the branch pipes 22, 23 at the exhaust outlet of each cylinder
Exhaust outlet pipes 10 and 11 that communicate with the cylinder row and extend along the cylinder row.
is covered with the exhaust outlet connecting pipe 13 that connects the turbocharger outlet and the power turbine 5, so the lengths of the exhaust manifold pipe 12 and the exhaust outlet connecting pipe 8 exposed to the outside are reduced as much as possible, reducing heat loss. This can greatly improve waste heat recovery efficiency. Moreover, exhaust collecting pipe 1
0, 11, 12, etc., and the exhaust outlet connecting pipe 13 for heat shielding can be provided along the outside thereof, so that the heat shielding structure is simplified from this point of view as well. Since the exhaust outlet connecting pipe 13 is disposed along the exhaust row and close to the side wall of the engine body, the engine is not bulky and the whole engine is compact.

[Brief explanation of drawings]

FIG. 1 is a layout diagram, FIG. 2 is a schematic side view, FIGS. 3 and 4 are cross-sectional views of FIG. 2, and FIG. 5 is a layout diagram of a conventional device. 5...Power turbine, 12...Exhaust outlet pipe,
13...Communication pipe.

Claims (1)

[Claims] 1 In a multi-cylinder diesel engine with a supercharger that supplies exhaust gas from the turbocharger outlet to a power turbine and recovers and uses exhaust heat, the supercharger is placed near the end of the cylinder row, and the exhaust gas from each cylinder is A multi-cylinder diesel engine with a supercharger, characterized in that it has a double structure by covering an exhaust outlet pipe that communicates with an outlet branch pipe and runs along a row of cylinders with an exhaust outlet connecting pipe that connects a supercharger outlet and a power turbine. Exhaust pipe device.