JP4194793B2 - Exhaust device with continuous regenerative particulate reduction device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exhaust device with a continuously regenerating fine particle reducing device disposed in a vehicle such as a truck.
[0002]
[Prior art]
Recently, in vehicles such as trucks, in order to efficiently purify exhaust gas from a diesel engine, a continuous regenerative particulate reduction device (DPF: diesel particulate filter) has been developed.
FIG. 6 shows an exhaust device equipped with such a continuously regenerating particulate reduction device, and a continuously regenerating particulate reducing device 2 is arranged downstream of the exhaust pipe 1.
[0003]
The continuous regeneration type particle reduction device 2 is configured by arranging an oxidation catalyst 4 and a filter 5 in a cylindrical casing 3.
Nitrogen monoxide or the like in the exhaust gas is oxidized by the oxidation catalyst 4, and the carbon collected by the filter 5 is oxidized and discharged as carbon dioxide to regenerate the filter.
And in such a continuous regeneration type | mold fine particle reduction apparatus 2, in order to perform a chemical reaction reliably, the temperature of the waste gas which flows into the continuous regeneration type | mold fine particle reduction apparatus 2 is requested to be 200 degreeC or more, for example. .
[0004]
[Problems to be solved by the invention]
However, in such an exhaust device with a continuous regenerative particulate reduction device, the exhaust gas G from the diesel engine passes through the exhaust pipe 1 and flows into the continuous regenerative particulate reduction device 2, so that the exhaust gas G passes through the exhaust pipe 1. There is a problem that heat escapes from the exhaust gas G, and it becomes difficult for the exhaust gas G of, for example, 200 ° C. or more to constantly flow into the continuous regeneration type particle reduction device 2.
[0005]
The present invention has been made to solve such a problem, and provides an exhaust device with a continuous regenerative particulate reduction device capable of reliably flowing exhaust gas having a predetermined temperature or more into the continuous regeneration particulate reduction device. Objective.
[0008]
[Means for Solving the Problems]
The exhaust device with a continuously regenerating particulate reduction device according to claim 1 is an exhaust device with a continuously regenerating particulate reducing device in which a continuous regeneration particulate reducing device is disposed downstream of the exhaust pipe . A heat insulating material formed by attaching a glass mat to the inner surface of the flexible tube is mounted, and an electric heating element having an outer periphery insulated is provided between the inner periphery of the glass mat and the outer periphery of the exhaust pipe. It is characterized by that.
[0011]
(Action)
In the exhaust device with the continuously regenerating fine particle reducing device according to the first aspect, the exhaust pipe is heated by the electric heating element, and the heated exhaust pipe is kept warm by the heat insulating material.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention shown in the drawings will be described.
[0013]
(First embodiment)
FIG. 1 shows a first embodiment of an exhaust device with a continuously regenerating particulate reduction device according to the present invention. In this embodiment, the present invention is applied to a vehicle such as a truck equipped with a diesel engine.
In FIG. 1, the code | symbol 11 has shown the exhaust pipe 11 connected to the diesel engine which is not shown in figure.
[0014]
The exhaust pipe 11 is formed of, for example, an aluminum plated steel pipe.
On the downstream side of the exhaust pipe 11, a continuously regenerating fine particle reducing device 15 is disposed via a heater device 13.
The continuously regenerating fine particle reducing device 15 has a cylindrical casing 17.
[0015]
An oxidation catalyst 19 and a filter 21 are accommodated in the casing 17.
An exhaust pipe 23 is connected to the upstream side of the casing 17, and an exhaust pipe 25 is connected to the downstream side.
A casing 29 of the heater device 13 is disposed between the exhaust pipe 23 on the upstream side of the casing 17 and the exhaust pipe 27 connected to the downstream side of the exhaust pipe 11.
[0016]
The casing 29 has an upstream end connected to the flange 31 of the exhaust pipe 27 and a downstream end connected to the flange 33 of the exhaust pipe 23.
The exhaust pipe 27 is connected to the flange portion 37 of the exhaust pipe 11 via the flange portion 35.
An electric heater 39 is disposed in the casing 29.
[0017]
The heater device 13 includes a temperature sensor 41 that is a temperature detection unit that measures the temperature of the exhaust gas flowing into the continuously regenerating particulate reduction device 15.
The temperature sensor 41 is disposed at the inlet of the casing 29 of the continuous regeneration type particle reducing device 15.
Further, the heater device 13 has a control device 43 that is a control means for energizing the electric heater 39 when the temperature of the exhaust gas G detected by the temperature sensor 41 is lower than a predetermined temperature.
[0018]
FIG. 2 shows details of the exhaust pipe 11, (a) is a top view, and (b) is a side view.
A heat insulating material 45 is attached to the outer periphery of the exhaust pipe 11.
The heat insulating material 45 is formed by attaching a glass mat 49 to the inner surface of the heat insulating flexible tube 47.
[0019]
The heat insulating material 45 is fixed to the exhaust pipe 11 by fixing bands 51 at the inlet portion, the intermediate portion, and the outlet portion of the exhaust pipe 11.
A tape (not shown) is wound around the end of the heat insulating material 45 to prevent water from entering.
[0020]
In the exhaust device with the continuous regeneration type particulate reduction device described above, exhaust gas G from a diesel engine (not shown) passes through the exhaust pipe 11, the exhaust pipe 27, the casing 29 of the heater device 13, and the exhaust pipe 23, and the continuous regeneration type particulate reduction device. Into the 15 casings 29.
[0021]
Nitrogen monoxide or the like in the exhaust gas is oxidized by the oxidation catalyst 19, and the carbon collected by the filter 21 is oxidized and discharged as carbon dioxide to regenerate the filter.
When the temperature of the exhaust gas G flowing into the casing 29 of the continuous regeneration type particle reducing device 15 is less than 200 ° C., the control device 43 energizes the electric heater 39.
[0022]
FIG. 3 shows a flowchart of the control device 43, which is started by starting the diesel engine.
First, in step S <b> 1, a signal from the temperature sensor 41 disposed in the casing 29 of the continuous regeneration type particle reducing device 15 is input.
Next, in step S2, it is determined whether the temperature detected by the temperature sensor 41 is lower than 200 ° C. or higher than 200 ° C.
[0023]
And when the temperature input from the temperature sensor 41 is less than 200 degreeC, electricity supply is performed to the electric heater 39 of the heater apparatus 13 in step S3.
In the exhaust device with the continuous regeneration type particle reduction device described above, the heater device 13 is disposed in the upstream exhaust pipe 23 of the continuous regeneration type particle reduction device 15, and the exhaust gas G from the exhaust pipe 11 is supplied by the electric heater 39 of the heater device 13. As a result, the exhaust gas G of 200 ° C. or higher can be surely flowed into the continuously regenerating fine particle reducing device 15.
[0024]
Further, in the above-described exhaust device with a continuously regenerating fine particle reducing device, the electric heater 39 is energized only when the temperature of the exhaust gas G is less than 200 ° C., and the exhaust gas G from the exhaust pipe 11 is heated. Power consumption can be reduced.
Furthermore, in the exhaust device with the continuous regeneration type particle reducing device described above, since the heat insulating material 45 is attached to the exhaust pipe 11, the heat radiation from the exhaust pipe 11 is reduced and the temperature of the exhaust gas G is effectively prevented from being lowered. be able to.
[0025]
Accordingly, the exhaust gas G can be reliably oxidized by the oxidation catalyst 19, and high purification efficiency can be obtained.
In this embodiment, the example in which the electric heater 39 of the heater device 13 is energized when the temperature input from the temperature sensor 41 is less than 200 ° C. has been described. However, the present invention is limited to this embodiment. Instead, it is desirable to change the set temperature according to the temperature of the exhaust gas G required for the continuously regenerating particulate reduction device 15.
[0026]
(Second Embodiment)
FIG. 4 shows the details of the main part of the second embodiment of the exhaust device with a continuously regenerating particulate reduction device of the present invention. In this embodiment, the heater device 13 of the first embodiment is arranged. In addition, the exhaust pipe 11 is connected to the upstream side of the casing 17 of the continuous regeneration type particulate reduction device 15.
[0027]
As shown in FIG. 5, a heat insulating material 45 is attached to the exhaust pipe 11.
The heat insulating material 45 is formed by attaching a glass mat 49 to the inner surface of the heat insulating flexible tube 47.
A linear electric heating element 55 whose outer periphery is insulated is disposed along the exhaust pipe 11 between the inner periphery of the glass mat 49 of the heat insulating material 45 and the outer periphery of the exhaust pipe 11.
[0028]
The outer circumference of the exhaust pipe 11 is heated by energizing the electrical heating element 55.
In this embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
In this embodiment, since the exhaust pipe 11 is heated by the electric heating element 55 and the heated exhaust pipe 11 is kept warm by the heat insulating material 45, it is possible to effectively prevent the temperature of the exhaust gas G from being lowered. Can do.
[0029]
Accordingly, the exhaust gas G can be reliably oxidized by the oxidation catalyst 19, and high purification efficiency can be obtained.
In this embodiment, the example in which the electrical heating element 55 is linear has been described. However, the present invention is not limited to this embodiment, and the electrical heating element may be planar.
[0030]
Further, a current may be directly applied to the exhaust pipe 11 or the exhaust pipe 11 itself may be heated by an eddy current.
Further, in this embodiment, the electrical heating element 55 may be energized only when the temperature of the exhaust gas G flowing into the casing 17 of the continuous regeneration type particle reduction device 15 is less than 200 ° C.
[0033]
【The invention's effect】
In the exhaust device with the continuous regenerative particulate reduction device according to claim 1, the exhaust pipe is heated by the electric heating element, and the heated exhaust pipe is kept warm by the heat insulating material. It can be effectively prevented.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a first embodiment of an exhaust device with a continuously regenerating particulate reduction device of the present invention.
2 is an explanatory view showing the exhaust pipe of FIG. 1. FIG.
FIG. 3 is a flowchart showing the operation of the control device of FIG. 1;
FIG. 4 is an explanatory view showing a second embodiment of an exhaust device with a continuously regenerating particulate reduction device of the present invention.
FIG. 5 is an explanatory view showing the exhaust pipe of FIG. 4;
FIG. 6 is an explanatory view showing a conventional exhaust device with a continuous regeneration type particle reducing device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Exhaust pipe 13 Heater apparatus 15 Continuous regeneration type | formula particulate reduction apparatus 39 Electric heater 41 Temperature sensor 43 Control apparatus 45 Heat insulating material 55 Electric heating element

Claims (1)

In the exhaust system with a continuously regenerating particulate reducing device, which is arranged downstream of the exhaust pipe,
A heat insulating material formed by attaching a glass mat to the inner surface of the heat insulating flexible tube is attached to the exhaust pipe, and the outer periphery is electrically insulated between the inner periphery of the glass mat and the outer periphery of the exhaust pipe. An exhaust device with a continuously regenerating fine particle reducing device, characterized by comprising a heating element .

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