JPS64578B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust gas treatment device for an internal combustion engine with an exhaust turbine supercharger.

As shown in the plan view shown in partial cross section in FIG. 1 and the enlarged side view shown in partial cross section in FIG. The exhaust turbine 3 is introduced into the exhaust turbine supercharger 4 via the manifold 2.
The supply air blower 6, which is coaxial with the exhaust turbine 3 and sucks and pressurizes the intake air A through the intake silencer 5, rotates, and the pressurized intake air A is passed through the intercooler 7 and the intake manifold 23, and then A conventional internal combustion engine with an exhaust turbine supercharger, in particular a direct injection type, introduces the exhaust gas E into each cylinder of the internal combustion engine and releases the exhaust gas E that drives the exhaust turbine 3 to the outside via the outlet bend 8 of the exhaust turbine 3. Internal combustion engines not only do not exhibit the supercharging effect of the exhaust turbine supercharger at low speeds and low loads, but also have a large amount of unresolved gas components in the exhaust gas, emit a large amount of blue-white smoke and a pungent exhaust odor. It is a problem in terms of pollution.

On the other hand, the invention of Japanese Patent Publication No. 52-25486 related to an exhaust toxicity removal device for an Otto engine and the invention of Japanese Patent Publication No. 1983-25048 related to an exhaust reburning device for a diesel engine.
As proposed in the above issue, even in internal combustion engines with an exhaust turbine supercharger, there is already a method in which the exhaust gas is burned at the exhaust turbine outlet of the exhaust supercharger to remove harmful components from the exhaust gas. Although this is known, in any of the above cases, the exhaust gas passes through the exhaust reburning device in the entire load range of the engine, so a large-sized device is required, and there are problems in terms of the durability of the device.

Further, in the above case, the fuel used in the afterburner device is not returned to the output of the internal combustion engine, and although the exhaust gas is purified, the energy of the fuel is not recovered, which is uneconomical.

Therefore, the present invention was made to solve the above-mentioned conventional problems, and only when combustion is poor at low speed or low load in the exhaust turbine overheating engine, exhaust gas is removed before being introduced into the exhaust turbine. ,
After being completely combusted by the afterburner device and catalyst section, it is introduced into the exhaust turbine, thereby increasing the boost pressure and reducing the engine's fuel consumption, as well as completely combusting the exhaust gas at low speeds or low loads. It is intended for measurement.

That is, the exhaust gas treatment device of the present invention provides a gate valve that closes only when the internal combustion engine is at low speed or under low load, at the outlet of the exhaust manifold of the internal combustion engine with an exhaust turbine supercharger and before the inlet of the exhaust turbine. At the same time, a bypass passage is provided that communicates with the exhaust turbine inlet from another outlet of the exhaust manifold, and a gate valve, an afterburner device, and a catalyst unit that open only at low speed or low load of the internal combustion engine are provided in the bypass passage. It is configured by the arrangement.

Embodiments of the present invention will be described below with reference to the drawings. In the conventional example shown in FIGS. 1 and 2 and in each embodiment, the same parts are indicated by the same part numbers.

First, in an internal combustion engine equipped with an exhaust turbine supercharger 4 in Embodiment 1 shown in FIG. 3, which has almost the same configuration and function as that in FIG. At the front, a gate valve 9 is provided which closes only when the internal combustion engine is at low speed or under low load.
A bypass passage 10 communicating with the inlet side of the exhaust turbine 3 is provided, and a gate valve 11 is provided in the bypass passage 10, which opens only when the internal combustion engine is at low speed or under low load.
After the gate valve 11, the afterburner device 13 and the catalyst section 16 are connected to the exhaust manifold 1.
It is placed parallel to the

FIG. 4 shows a state in which the gate valve 9 is closed and the gate valve 11 is opened when the internal combustion engine is at low speed or under low load in the above exhaust gas treatment device, and the afterburner device 13 is connected to the fuel injection valve. 1
2. Consists of a burner device 14, a spark plug 15, etc.
Exhaust gas E from the exhaust manifold 2 is heated in this afterburner device 13 and re-burned, and after oxidizing unburned components in the catalyst section 16, it is introduced into the exhaust turbine 3. The rotation of the exhaust turbine 3 can be increased by the energy generated by the reburning of the exhaust gas in the portion and the combustion by the afterburner.

In this case, the closing of the gate valve 9, the opening of the gate valve 11, the ignition of the spark plug 15 of the afterburner device 13, etc. are performed in conjunction with each other.

Next, FIG. 5 shows a state in which the internal combustion engine is operated at normal engine speed and output, the gate valve 9 is open, the gate valve 11 is closed, and the afterburner device 13 is not operated. Exhaust gas E is introduced directly from the exhaust manifold 2 into the exhaust turbine 3.

Here, to explain the operating range of the exhaust gas treatment device in the above-mentioned Example 1 using the relationship diagram between engine output and engine speed in Fig. 6, the range shown by the diagonal line A at low output when the engine is idling is This is the complete operating range of the exhaust gas treatment device, and the range indicated by the diagonal line B is where a portion of the exhaust gas E is treated by the operation of the afterburner device 13 under the intermediate opening degree of each gate valve 9 and 11. This is the half-operation region, and the range indicated by arrow C shows the normal operation in the state shown in FIG. 5, in which the gate valve 9 is open, the gate valve 11 is closed, and the afterburner device 13 is stopped.

Furthermore, a second embodiment shown in FIGS. 7 and 8 shows an exhaust gas treatment device for an internal combustion engine having an exhaust turbine supercharger 4 having almost the same configuration and function as the first embodiment. 2, the nozzle case of the exhaust turbine 3 is divided into two parts, and the outlet part of the exhaust manifold 2 is also divided into two parts, and the central partition part 2A of the outlet part has an exhaust manifold which is shared with the partition wall. A two-outlet gate valve 9A is provided, and an exhaust gas processing section outlet valve 17 is provided in the passage from the afterburner device 13 side to the exhaust turbine 3 inlet.

That is, when the internal combustion engine is running at low speed or under low load, the gate valve 9A at the outlet of the exhaust manifold 2 is closed, the exhaust gas treatment section outlet valve 17 is opened, and the gate valve 11 is opened, as shown in FIG. After the exhaust gas is completely combusted in the afterburner device 13 and the catalyst section 16 to increase the exhaust energy, only one side of the exhaust gas is passed through the inlet of the exhaust turbine 3 which is divided into two parts, and the exhaust gas is supplied to the exhaust turbine 3. This increases air pressure and increases turbine efficiency.

Note that during normal operation of the internal combustion engine at medium speed and medium load or higher, as shown in FIG. 8, the gate valve 9A is opened, the gate valve 11 is closed, the exhaust gas treatment section outlet valve 17 is closed, and The afterburner device 13 is stopped.

Here, P ₁ is the supercharging air pressure of the internal combustion engine in the conventional example shown in FIG. 1, P ₂ is the supercharging air pressure of the internal combustion engine in the first embodiment shown in FIG. If the supercharging air pressure is P ₃ and the relationship between engine speed and output is shown in the diagram in Figure 9, the full operating range A of the exhaust gas treatment device at idle and diagonal line A as shown in the diagram in Figure 6 is shown in Figure 9. and diagonal line B
With respect to the half-operating region B, the supply pressure of the first embodiment is increased by the area indicated by the diagonal line X compared to the conventional example, and the supply pressure of the second embodiment is further improved by the area indicated by the diagonal line Y than the example 1.

By increasing the supply pressure, good combustion is obtained, and high output is obtained as a low compression ratio engine under the same limited cylinder internal pressure, and exhaust gas E is completely combusted even at low speeds or low loads. It will be processed and release clean exhaust gas.

Therefore, by applying the present invention, the exhaust gas is completely combusted at low engine speeds or under low load, eliminating blue-white smoke and pungent exhaust odor, and the exhaust turbine can be rotated using the energy from the complete combustion of the exhaust gas. As the boost pressure increases, the fuel consumption of the internal combustion engine also decreases.

That is, the present invention has the advantage that the energy generated by the afterburner device and the energy generated by the combustion of the exhaust gas from the internal combustion engine are recovered to the engine via the exhaust turbine.

Note that the present invention can be effectively applied to an internal combustion engine with an exhaust turbine supercharger, particularly a direct injection type diesel or gasoline engine.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional plan view of a conventional internal combustion engine with an exhaust turbine supercharger, FIG. 2 is a partially sectional side view of the exhaust turbine supercharger of FIG. A partial cross-sectional plan view of the internal combustion engine with an exhaust turbine supercharger in Example 1, FIGS. 4 and 5 are shown in FIG.
FIG. 6 is a relationship diagram between engine speed and engine output showing the operating range of the exhaust gas treatment device of Example 1, and FIGS. 7 and 8 are according to the present invention. FIG. 9 is a side sectional view of an exhaust gas treatment device for an internal combustion engine with an exhaust turbine supercharger according to Embodiment 2, and FIG. It is a diagram comparing supply air pressure. 2...Exhaust manifold, 3...Exhaust turbine, 4...Exhaust turbine supercharger, 9,9A...Gate valve, 10...Bypass passage, 11...Gate valve,
13... Afterburner device, 16... Catalyst section.

Claims (1)

[Claims] 1 At the outlet of the exhaust manifold of an internal combustion engine with an exhaust turbine supercharger and before the inlet of the exhaust turbine, a gate valve is provided that closes only when the internal combustion engine is at low speed or under low load, and at the other outlet of the exhaust manifold. An exhaust turbine characterized in that a bypass passage is provided that communicates with an inlet of the exhaust turbine, and a gate valve that opens only when the internal combustion engine is running at low speed or under low load, an afterburner device, and a catalyst section are arranged in the bypass passage. Exhaust gas treatment device for internal combustion engine with supercharger.