KR20030087916A - Egr equipment - Google Patents

Abstract

SUMMARY OF THE INVENTION An object of the present invention is to provide an EZR device in which the components of the EZR device are not corroded by the condensed water of the exhaust gas generated in the EGR cooler.

As a means for solving the above problems, the plates 22 and 22 are fixedly attached to both ends of the shell 21 in the axial direction, and both ends of the plurality of tubes 23 arranged in parallel in the axial direction are penetrated. It is fixedly attached to the plates 22 and 22. An inlet bonnet 30 having an exhaust gas inlet 32 is fixedly attached to one end of the shell 21 in the axial direction, and the bottom portion 34 of the exhaust gas passage is flush with the bottom surface of the shell 21. Or downward. An air outlet bonnet 31 having an exhaust gas outlet 33 is fixedly attached to the other axial end of the shell 21 to form an ERG cooler 20. The bottom surface of the shell 21 of the EZC cooler 20 is configured by placing the exhaust gas inlet 32 side downward by an angle θ (at least 5 °).

Description

EZR Device {EGR EQUIPMENT}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an EZR device equipped with an EGR cooler which cools exhaust gas of an engine recycled to intake and efficiently reduces generation of nitrogen oxides.

Background Art Conventionally, an IZR apparatus is known which recycles a part of an exhaust gas of an engine to intake to reduce generation of nitrogen oxides. In such an EZR apparatus, when the temperature of the exhaust gas to be recycled is lowered, the volume becomes smaller, and the combustion temperature can be lowered without significantly reducing the engine output, thereby effectively reducing the generation of nitrogen oxides. Therefore, there is a case in which an EG cooler is installed in the exhaust gas recirculation line to cool the exhaust gas.

Fig. 2 is a schematic configuration diagram of a turbo-charger type engine 1 equipped with an IG cooler type ESR device. In Fig. 2, an intake pipe 3 is attached to the inlet port of the compressor 2a of the supercharger 2, and the outlet port of the compressor 2a and the intake manifold 5 of the engine 1 are shown. Is connected by a supply pipe (4). The turbine 2b of the supercharger 2 is connected to the discharge port of the exhaust manifold 6 of the engine 1, and the exhaust pipe 7 is attached to the discharge port of the turbine 2b. An upstream portion of the turbine 2b of the exhaust manifold 6 and an upstream portion of the intake manifold 5 are connected by an EG pipe 11, and an EG valve 12 and an EG pipe 12. The EG cooler 20 is provided and comprises the EG apparatus 10.

Next, the operation will be described. When the engine 1 is started, air is sucked from the intake pipe 3, compressed by the compressor 2a, and supplied into the engine 1 through the intake manifold 5. The exhaust gas generated by combustion in the engine 1 is discharged from the exhaust pipe 7 from the exhaust manifold 6 via the turbine 2b. In the normal state, since the exhaust gas pressure is higher than the intake pressure, a part of the exhaust gas returns to the intake manifold 5 through the easy R pipe 11 when the easy valve 12 is opened. At this time, the exhaust gas is cooled by the EG cooler 20. The easy valve 12 is opened and closed as necessary.

There are many kinds of EZC coolers, and there is one disclosed in Japanese Laid-Open Patent Publication No. 2001-74380. FIG. 3 is a side cross-sectional view of the EZR cooler 40 disclosed in Japanese Patent Laid-Open No. 2001-74380, and FIG. 4 is a cross-sectional view taken along line X-X in FIG. 3 and 4, plates 22 and 22 are fixedly attached to both ends in the axial direction of the shell 21 formed in a cylindrical shape, and the plates 21 and 22 are attached to the plates 22 and 22, respectively. Both ends of the plurality of tubes 23 arranged substantially in parallel in the axial direction are fixedly attached in a penetrating state. A cooling water inlet 24 is attached near one end of the shell 21, and a cooling water outlet 25 is attached near the other end of the shell 21. In addition, a bypass outlet 26 is provided at a position facing the cooling water inlet 24 of the shell 21. At both ends of the shell 21 in the axial direction, an inlet bonnet 41 and an outlet bonnet 31 formed in the shape of air are fixedly attached to cover the plates 22 and 22. An exhaust gas inlet 32 is provided in the center of the inlet bonnet 41, and an exhaust gas outlet 33 is provided in the center of the outlet bonnet 30.

The EG cooler 40 is disposed so that the shell 21 is horizontal, and the recirculating exhaust gas enters from the exhaust gas inlet 32, passes through the tube 23, and is discharged from the exhaust gas outlet 33. . Cooling water enters from the cooling water inlet 24, passes through the shell 21, is discharged from the cooling water outlet 25, and some is discharged from the bypass outlet 26, during which the exhaust gas is cooled. At that time, part of the cooling water is discharged from the bypass outlet 26, so that clogging of the cooling water in this part is eliminated, and the cooling efficiency of the EG cooler 20 is improved.

Cooling the exhaust gas produces condensate. This condensate contains nitric acid and sulfuric acid combined with sulfur in the fuel component. In particular, sulfuric acid is highly corrosive, and corrodes the EG cooler, pipes, EZ valves, etc., which are parts of the IG circuit. In FIG. 3, the exhaust gas temperature of the A part in the inlet bonnet 41 is high (for example, 400 ° C. to 500 ° C. under an engine load), and condensate does not occur, but the exhaust gas temperature of the B part of the outlet bonnet 31 is increased. Since it is lowered, condensed water is generated at the exhaust gas outlet 33 side.

That is, in the above configuration, condensed water accumulates near the bottom portion C (dashed line portion) on the outlet bonnet 31 side of the EG cooler 40 shown in Fig. 3, and the EZC cooler 40 is corroded. There is this. Moreover, there exists a danger that this condensate may corrode the EG pipe 11 and the EG valve 12 shown in FIG.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide an EG apparatus which is not likely to corrode parts of an EG apparatus by condensed water of exhaust gas generated in an EZC cooler.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side cross-sectional view of an EGR cooler of an ERL device of the present invention.

2 is a schematic configuration diagram of a turbocharger-attached engine equipped with an EZR device.

Figure 3 is a side cross-sectional view of a conventional EG cooler.

4 is a cross-sectional view taken along the line X-X of FIG.

[Explanation of symbols on the main parts of the drawings]

10: EZR apparatus 11: EGR piping 20: EGR cooler

21 Shell 22 Plate 23 Tube 30 Inlet bonnet 31 Outlet bonnet

32: exhaust gas inlet 33: exhaust gas outlet 34: bottom 35: exhaust gas passage

In order to achieve the above object, the first invention has a configuration in which the exhaust gas passage of the EG cooler provided in the EG pipe is arranged so that the exhaust gas inlet side is lower than the exhaust gas outlet side in the EZR apparatus. Doing.

According to the first invention, the condensed water of the exhaust gas containing nitric acid or sulfuric acid flows to the exhaust gas inlet side having a high exhaust gas temperature. Sulfuric acid has a property of decomposing when it is 350 deg. C or higher, and sulfuric acid flowing to the exhaust gas inlet side is decomposed and evaporated by the high-temperature exhaust gas, thereby preventing corrosion of parts of the EG apparatus.

According to a second invention, in the first invention, the exhaust gas passage is inclined at least 5 ° with respect to a horizontal plane with the exhaust gas inlet side facing downward.

According to the second invention, the bottom portion of the exhaust gas passage is inclined at least 5 ° with respect to the horizontal plane with the exhaust gas inlet side down, so that the condensate flows reliably to the exhaust gas inlet side. Therefore, sulfuric acid can be dispersed and evaporated by the high-temperature exhaust gas to prevent corrosion of the parts of the ezr apparatus. In addition, it was experimentally confirmed that the condensate flowed reliably by inclining the exhaust gas passage 5 ° or more.

According to a third invention, in the first or second invention, the bottom portion of the exhaust gas passage is formed to gradually decrease from the exhaust gas outlet side toward the exhaust gas inlet side.

According to the third invention, since there is no high portion in the middle of the bottom of the exhaust gas passage, the condensed water can flow reliably toward the exhaust gas inlet without stagnation in the middle of the exhaust gas passage.

EXAMPLE

EMBODIMENT OF THE INVENTION Below, the Example of the EG apparatus which concerns on this invention is described in detail, referring drawings.

1 is a side sectional view showing an EG cooler 20 as an example of an EZ device 10. As shown in FIG. Since the front cross-sectional shape of the EG cooler 20 is the same as the conventional one shown in FIG. 4, the detailed description is omitted. In FIG. 1, the same code | symbol is attached | subjected to the same member as the conventional thing demonstrated in FIG. 3, description is abbreviate | omitted, and only another part is demonstrated.

In Fig. 1, an inlet bonnet 30 is fixedly attached to one side of the shell 21, and an EG pipe 11 is connected to an exhaust gas inlet 32 provided at an end of the inlet bonnet 30. The bottom portion 34 of the exhaust gas inlet 32 portion of the inlet bonnet 30 is formed flush with the inner bottom surface of the shell 21 or downwards from the plate 22 portion toward the exhaust gas inlet 32. It is. An EG pipe 11 is connected to the exhaust gas outlet 33 provided in the center of the air outlet bonnet 31 fixedly attached to the other end of the shell 21. The exhaust gas passage 35 is formed by the exhaust gas inlet 32, the tube 23, and the exhaust gas outlet 33. The EG cooler 20 is arranged to be inclined with the outlet bonnet 31 side high, and the inclination angle θ of the bottom surface of the shell 21 with respect to the horizontal plane is at least 5 °. Therefore, the bottom portion of the exhaust gas passage 35 is gradually lowered from the exhaust gas outlet 33 toward the exhaust gas inlet 32. The exhaust gas flows in the direction of the white arrow in the figure.

Since the EG cooler 20 of the EG apparatus 10 of the present invention is configured as described above, the condensed water generated in the exhaust gas does not stagnate on the way, but is exhausted from the exhaust gas outlet 33 side. 32) The harmful sulfuric acid contained in the condensate is decomposed and evaporated by the hot exhaust gas. Therefore, the EG apparatus 10 with which there is no possibility that the EG cooler 20, the EG pipe 11, the EG valve 12, etc. may corrode can be obtained.

In this embodiment, the cross-sectional shape of the EZC cooler may be circular, quadrilateral, or another shape.

An object of the present invention is to provide an IJ device in which the parts of the IJ device 10 are not corroded by the condensed water of the exhaust gas generated in the IJ cooler 20.

As a means for solving the above problem, the plates 22 and 22 are fixedly attached to both ends of the shell 21 in the axial direction, and both ends of the plurality of tubes 23 arranged in parallel in the axial direction are penetrated. 22) and fix it. The inlet bonnet 30 having the exhaust gas inlet 32 is fixedly attached to one end of the shell 21 in the axial direction, and the bottom portion 34 of the exhaust gas passage is flush with the bottom surface of the shell 21 or Form downward.

Next, an outlet bonnet 31 having an air shape having an exhaust gas outlet 33 is fixedly attached to the other end of the shell 21 in the axial direction to form the EZR cooler 20. The condensate of the exhaust gas containing nitric acid or sulfuric acid in a configuration in which the bottom surface of the shell 21 of the EZR cooler 20 is disposed with respect to the horizontal surface with the exhaust gas inlet 32 side down by an angle θ (at least 5 °). Flows to the exhaust gas with a high exhaust gas temperature. That is, since sulfuric acid has a property of decomposing when it is 350 ° C. or higher, sulfuric acid flowing to the exhaust gas inlet 32 side is decomposed and evaporated by the high temperature exhaust gas, thereby preventing corrosion of the components of the EZR device 10.

In addition, the bottom of the exhaust gas passage (35) with the exhaust gas inlet 32 side down 5 Since it is formed to be inclined or gradually lowered, condensate can reliably flow from the exhaust gas outlet 33 side toward the exhaust gas inlet 32 side, so sulfuric acid is dispersed and evaporated by the high temperature exhaust gas to It is effective in preventing corrosion of parts.

Claims (3)

In the EG apparatus 10, the exhaust gas passage 35 of the EGR cooler 20 provided in the EGR piping 11 is connected to the exhaust gas inlet 32 side. EGR EQUIPMENT characterized by arrange | positioning so that it may become below (33) side. The device of claim 1, wherein the exhaust gas passage (35) is inclined at least 5 degrees with respect to a horizontal plane with the exhaust gas inlet (32) side down. The easy portion according to claim 1 or 2, wherein the bottom portion of the exhaust gas passage (35) is formed to gradually decrease from the exhaust gas outlet (33) toward the exhaust gas inlet (32). Al device.