JP2003161208A - Auxiliary starting device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To securely improve engine startability. <P>SOLUTION: Combustion gas of a combustor 120 is supplied into an intake air side of an engine 10 at engine start and a carbon dioxide absorber 127 is installed in an exhaust pipe 126 for the combustor in which combustion gas flows. Since high-temperature steam from which carbon dioxide is removed by the carbon dioxide absorber 127 and activated high-temperature carbon monoxide are supplied into the engine 110, the ignition startability of the engine 110 is securely improved. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine start-up assisting device for assisting the start-up of an internal combustion engine, which is effective when applied to a vehicle diesel engine.

[0002]

2. Description of the Related Art As a start assisting device for an internal combustion engine, for example, Japanese Patent Publication No. 6-13251.
In the invention described in the publication, the combustion gas generated in the heating combustor is supplied to the intake pipe of the engine to heat the engine, particularly the combustion chamber, to improve the startability of the engine.

However, in the above invention, although the combustion chamber can be heated, a large amount of carbon dioxide is supplied to the engine, so the concentration of oxygen in the intake air decreases, and rather the engine starts. May deteriorate.

In view of the above points, an object of the present invention is to reliably improve the startability of an internal combustion engine.

[0005]

In order to achieve the above object, the present invention provides the exhaust gas discharged from the combustor (120) at the time of starting the internal combustion engine (110) in the invention described in claim 1. The internal combustion engine (110) is heated by being supplied to the intake side of the internal combustion engine (110).
Is a start-up assisting device for an internal combustion engine, wherein carbon dioxide removing means (127) for removing carbon dioxide from exhaust gas is provided in a passage through which exhaust gas of a combustor (120) flows. To do.

As a result, high temperature steam from which carbon dioxide has been removed and activated high temperature carbon monoxide are supplied to the internal combustion engine (110), so that the ignition startability of the internal combustion engine (110) is reliably improved. Can be made.

According to the second aspect of the invention, the internal combustion engine (1
A starting assist device for an internal combustion engine, which assists the starting of the internal combustion engine (110) when starting the internal combustion engine (110).
Carbon dioxide that removes carbon dioxide from the exhaust gas in the path through which the exhaust gas discharged from the exhaust gas (0) is supplied to the intake side of the internal combustion engine (110) and the exhaust gas supplied to the intake side of the internal combustion engine (110) flows. The removing means (127) is provided.

As a result, the exhaust gas that has been compressed by the internal combustion engine (110) and has reached a high temperature is supplied to the internal combustion engine (110). (110) can be easily started. Moreover, since high-temperature exhaust gas from which carbon dioxide has been removed by the carbon dioxide removing means (127) is supplied, the ignition startability of the internal combustion engine (110) is more reliably improved as in the case of the invention according to claim 1. Can be made.

Incidentally, after the internal combustion engine (110) is stably operated, in the invention according to claim 3, the internal combustion engine (110) is
It is desirable to adjust the amount of exhaust gas supplied to the intake side of the vehicle based on exhaust gas recirculation control for reducing nitrogen oxides in the exhaust gas discharged from the internal combustion engine (110).

According to the invention of claim 4, the internal combustion engine (1
The exhaust gas passing through the catalyst (115) for purifying the exhaust gas of (10) is supplied to the intake side of the internal combustion engine (110).

As a result, the temperature of the catalyst (115) can be quickly raised to the activation temperature.

In the invention described in claim 5, the catalyst (11
After the temperature of 5) exceeds a predetermined temperature, the internal combustion engine (1
The amount of exhaust gas supplied to the intake side of the internal combustion engine (11)
It is characterized in that it is adjusted based on an exhaust gas recirculation control for reducing nitrogen oxides in the exhaust gas discharged from 0).

As a result, while the temperature of the catalyst (115) is low and the exhaust gas cannot be sufficiently purified, the exhaust gas will not be released into the atmosphere but will continue to be recirculated in the internal combustion engine (110). Improving the startability of the internal combustion engine (110) while preventing exhaust gas that has not been sufficiently purified being released into the atmosphere even when the catalyst temperature is low immediately after the internal combustion engine (110) is started. be able to.

The carbon dioxide removing means (127) is
As in the invention described in claim 6, it may be configured by a carbon dioxide absorbent that absorbs carbon dioxide at a predetermined temperature or lower and releases carbon dioxide at a temperature higher than the predetermined temperature.

According to a seventh aspect of the present invention, the temperature at which the carbon dioxide absorbent begins to release carbon dioxide is lower than at least the maximum temperature of the exhaust gas supplied to the intake side of the internal combustion engine (110). .

As a result, the carbon dioxide absorbent can be reliably regenerated.

The carbon dioxide removing means (127) is
As in the invention described in claim 8, as a separation membrane for separating and extracting carbon dioxide, the carbon dioxide separated and extracted by the carbon dioxide removing means (127) may be discharged into the atmosphere.

Incidentally, the reference numerals in parentheses of the above-mentioned respective means are examples showing the correspondence with the concrete means described in the embodiments described later.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment)
The internal combustion engine starting auxiliary device according to the present invention is applied to a vehicle diesel engine, and FIG. 1 is a schematic diagram of the starting auxiliary device 100 according to the present embodiment.

The engine 110 is a heat engine that compresses atomized fuel together with air and spontaneously ignites it to obtain power, and the combustor 120 generates heat by burning the fuel. In this case, the combustor 120 is used as a heat source for starting the engine 110 and a heat source for heating.

Here, the combustor 120 holds a liquid fuel by a combustion cylinder 121 for combusting fuel, a heat exchange section 122 for exchanging heat between combustion gas as exhaust gas of the combustor 120 and engine cooling water, and surface tension. A wick 123 that promotes vaporization of the fuel, a glow plug 124 that is disposed near the wick 123 and heats the fuel when the combustor 120 is started,
And an air pump 125 or the like for blowing combustion air.

In FIG. 1, the combustor 120 and the engine 1 are shown.
The engine cooling water heated by the combustor 120 is indirectly supplied to the heating heater core (not shown) by circulating the engine cooling water with the combustor 120. The engine cooling water heated by the above may be directly supplied to the heater core for heating.

Further, the intake pipe 125 for the combustor is the engine 1
The air pump 12 is connected to the intake pipe 111
3 sucks a part of the air flowing in the intake pipe 111 and supplies it to the combustion cylinder 121.

On the other hand, the combustor exhaust pipe 126 through which the combustion gas discharged from the combustor 120 flows is connected to the intake pipe 111 of the engine 110 on the downstream side of the combustor intake pipe 125 in the air flow direction. The combustion gas of
It is discharged into the intake pipe 111 of the engine 110.

Although not shown in FIG. 1, the combustor intake pipe 12 in the intake pipe 111 of the engine 110 is not shown.
It is desirable to provide a throttle valve, a fixed throttle, or the like, which generates a predetermined pressure loss, between the connection portion with the No. 5 and the connection portion with the combustor exhaust pipe 126.

The exhaust pipe 126 for the combustor is provided with a carbon dioxide absorber 127 which serves as a carbon dioxide removing means for absorbing and removing carbon dioxide in the combustion gas. It is composed of a carbon dioxide absorbent composed of a complex oxide.

As shown in FIG. 2, this carbon dioxide absorbing material absorbs carbon dioxide when the temperature of the carbon dioxide absorbing material is equal to or lower than the predetermined temperature To, and absorbs when the temperature of the carbon dioxide absorbing material is equal to or higher than the predetermined temperature To. The carbon dioxide absorbent has a property of releasing carbon dioxide, and in the present embodiment, the carbon dioxide absorbent is at least at a temperature lower than the maximum temperature of the combustion gas that can be supplied to the intake pipe 111 by the combustor 120. We have selected a carbon dioxide absorber that will begin to release carbon. The predetermined temperature To is not a clear temperature,
It has a predetermined temperature range.

Further, in FIG. 1, the water temperature sensor 112 detects the temperature of the engine cooling water, and the glow plug 113 heats the air drawn into the engine 110.

Next, the characteristic operation and effect of the internal combustion engine starting assist system according to the present embodiment will be described.

After the starter motor for rotating the crankshaft of the engine 110 is turned on, the combustor 120 is operated and the glow plug 113 is energized before the starter motor actually rotates.

As a result, when the starter motor rotates and cranking is performed, the combustion gas of the combustor 120 is sucked into the engine 110 together with the air flowing in the intake pipe 111. At this time, since the combustion gas supplied to the engine 110 is high-temperature steam from which carbon dioxide has been removed by the carbon dioxide absorber 127 and activated high-temperature carbon monoxide, the ignition startability of the engine 110 is promoted. It

When the temperature of the engine cooling water detected by the water temperature sensor 112 becomes equal to or higher than the warm-up end temperature T1 which is estimated to be the stable operation state of the engine 110, the heat generation amount of the combustor 120 Is increased to raise the temperature of the combustion gas, and the temperature of the carbon dioxide absorbent is raised to a predetermined temperature To or higher to release the absorbed carbon dioxide.

The released carbon dioxide is sucked into the engine 110, but there is no problem because the engine 110 is in a stable operating state. Rather, the emitted carbon dioxide can suppress an increase in the combustion temperature of the engine 110, so that the engine 1 can operate like an exhaust gas recirculation device (EGR).
It is possible to reduce the amount of nitrogen oxides in the exhaust gas discharged from 10.

Incidentally, as is well known, the exhaust gas recirculation device means that the exhaust gas discharged from the engine 110 is exhausted from the engine 11
By inhaling the exhaust gas to 0 and recirculating the exhaust gas, the increase in the combustion temperature of the engine 110 is suppressed and the generation of nitrogen oxides is suppressed.

After the regeneration work for releasing the carbon dioxide absorbed by the carbon dioxide absorbent is completed, the temperature of the engine cooling water is within the upper limit temperature T2 which is higher than the warm-up operation termination temperature T1. The combustor 120 is operated to assist the heating capacity.

(Second Embodiment) In the first embodiment, the combustion gas of the combustor 120 is supplied to the intake pipe 111 to improve the startability of the engine 110. As shown in FIG. 3, the existing exhaust gas recirculation device 130 is used to improve the startability of the engine 110.

Specifically, the exhaust gas recirculation pipe 131 for guiding the exhaust gas of the engine 110 to the intake pipe 111 is connected to the engine 110.
The exhaust pipe 114 is connected to the exhaust flow downstream side of the catalyst 115 to guide the exhaust gas passing through the catalyst 115 to the intake pipe 111, and the exhaust gas recirculation pipe 131 and the exhaust pipe 1
A variable exhaust throttle 132 is provided in the exhaust pipe 114 on the downstream side of the exhaust flow from the joint with the exhaust pipe 14, and an EGR valve 133 for adjusting the degree of communication of the exhaust recirculation pipe 131 is provided in the exhaust recirculation pipe 131. Carbon dioxide absorber 1 in the circulation pipe 131
27 is provided.

The variable exhaust throttle 132 is provided in the exhaust pipe 11.
The intake pipe 11 of the exhaust gas recirculation pipe 131
A pressure difference is generated between the No. 1 side and the exhaust pipe 114 side, and exhaust gas recirculation control for reducing nitrogen oxides is performed by interlocking the exhaust variable throttle 132 and the EGR valve 133.

Next, the characteristic operation and effect of the internal combustion engine starting assist system according to the present embodiment will be described.

At the same time when the switch of the starter motor is turned on, the glow plug 113 is energized and the EG
The R valve 133 is fully opened, the opening of the exhaust variable throttle 132 is reduced, and then the starter motor is actually rotated.

As a result, when the starter motor rotates and cranking is performed, most of the exhaust gas discharged from the engine 110 passes through the catalyst 115 and then flows through the exhaust gas recirculation pipe 131 to the intake side. Circulated.

At this time, since the exhaust gas which has been compressed by the engine 110 and becomes high temperature and burned is supplied to the engine 110, the engine 110 can be started more easily than in the case where it is simply sucked from the outside air for compression ignition. Can be made. Moreover, since high-temperature exhaust gas from which carbon dioxide has been removed by the carbon dioxide absorber 127 is supplied, the ignition startability of the engine 110 can be promoted more reliably.

After the temperature of the catalyst 115 detected by the catalyst temperature sensor 116 has risen to the activation temperature of the catalyst 115 or higher, normal exhaust gas recirculation control for reducing nitrogen oxides is performed.

As a result, while the temperature of the catalyst 115 is low and exhaust gas cannot be sufficiently purified, exhaust gas is not released into the atmosphere and continues to be recirculated in the engine 110. Therefore, immediately after the engine 110 is started. Even when the catalyst temperature is low, it is possible to improve the startability of the engine 110 while preventing exhaust gas that has not been sufficiently purified from being released into the atmosphere.

Since the time required for the catalyst 115 to reach the activation temperature is usually longer than the time until the warm-up operation of the engine 110 is completed and the operating state of the engine 110 is stabilized, the catalyst 115 is Performing the normal exhaust gas recirculation control after the temperature rises above the activation temperature is equivalent to performing the normal exhaust gas recirculation control after the engine 110 operates stably.

Further, in the present embodiment, the exhaust gas after passing through the catalyst 115 is guided to the exhaust gas recirculation pipe 131, so that the catalyst 1
The temperature of 15 can be raised early to the activation temperature.

In this embodiment, the normal exhaust gas recirculation control is performed after the catalyst 115 has risen to the activation temperature or higher, but of course, the temperature of the engine cooling water becomes the warm-up operation end temperature T1 or higher. The normal exhaust gas recirculation control may be performed after the engine 110 is in the stable operation state.

Incidentally, when the exhaust gas temperature rises, the carbon dioxide absorbed by the carbon dioxide absorber 127 is released. However, as described in the first embodiment, the combustion temperature rise of the engine 110 can be suppressed. Similar to the original function of the exhaust gas recirculation device 130, nitrogen oxides in the exhaust gas emitted from the engine 110 can be reduced.

In this embodiment, since the carbon dioxide absorbent is regenerated by the exhaust gas of the engine 110, the carbon dioxide absorbent whose starting temperature of carbon dioxide release is lower than the exhaust temperature of the engine 110 is selected. There is a need.

(Third Embodiment) This embodiment is a modification of the second embodiment, and as shown in FIG. 4, the exhaust gas recirculation pipe 13
1 is connected to an exhaust flow upstream side of the catalyst 115 in the exhaust pipe 114 of the engine 110, and the variable exhaust throttle 1
In place of 32, an intake variable throttle 118 in the intake pipe 111 is provided, and the exhaust recirculation pipe 131 on the intake pipe 111 side and the exhaust pipe 1 are provided.
It is configured to generate a pressure difference with the 14 side.

In this embodiment, most of the exhaust gas is guided to the intake pipe 111 without passing through the catalyst 115 when the engine is started. Therefore, the exhaust gas temperature sensor 117 is provided in place of the catalyst temperature sensor 116 and the exhaust gas temperature sensor 117 is exhausted. Air temperature sensor 117
When the exhaust gas temperature detected by the engine exceeds a predetermined temperature, it is considered that the engine 110 is in a stable operation state,
After that, normal exhaust gas recirculation control is performed.

(Other Embodiments) In the above-described embodiment, it is determined whether or not the engine 110 is in a stable operation state based on the temperature of the engine cooling water, but the present invention is not limited to this. Alternatively, the determination may be made based on other parameters such as the temperature of the air taken into the engine 110, the engine speed, the temperature of the engine oil, and the like.

In the above embodiment, the carbon dioxide absorbent is used as the carbon dioxide removing means, but the present invention is not limited to this, and a separation membrane for separating and extracting carbon dioxide may be used. . In this case, it is necessary to discharge the separated and extracted carbon dioxide into the atmosphere.

[Brief description of drawings]

FIG. 1 is a diagram showing a start assist device for an internal combustion engine according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing characteristics of a carbon dioxide absorber.

FIG. 3 is a diagram showing a start assist device for an internal combustion engine according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a start assist device for an internal combustion engine according to a third embodiment of the present invention.

[Explanation of symbols]

110 ... Engine, 120 ... Combustor, 126 ... Combustor exhaust pipe 127 ... Carbon dioxide absorber

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Claims (8)

[Claims] 1. When the internal combustion engine (110) is started, the exhaust gas discharged from the combustor (120) is supplied to the internal combustion engine (11).
0) to the intake side of the internal combustion engine (11
0) for heating the internal combustion engine (110) to assist in starting the internal combustion engine (110), and a carbon dioxide for removing carbon dioxide from the exhaust gas in a path through which the exhaust gas of the combustor (120) flows. Carbon removal means (12
7) The start assisting device for an internal combustion engine, characterized by being provided. 2. A start assist device for an internal combustion engine, which assists in starting the internal combustion engine (110), wherein the internal combustion engine (1) is activated when the internal combustion engine (110) is started.
Exhaust gas discharged from 10) is supplied to the intake side of the internal combustion engine (110), and carbon dioxide is removed from the exhaust gas in a path along which the exhaust gas supplied to the intake side of the internal combustion engine (110) flows. A starting aid device for an internal combustion engine, which is provided with a carbon dioxide removing means (127). 3. After stable operation of the internal combustion engine (110), the amount of exhaust gas supplied to the intake side of the internal combustion engine (110) is adjusted by nitrogen oxidation in the exhaust gas discharged from the internal combustion engine (110). 3. The start assist device for an internal combustion engine according to claim 2, wherein the adjustment is performed based on an exhaust gas recirculation control for reducing the amount of substances. 4. Exhaust gas that has passed through a catalyst (115) for purifying exhaust gas of the internal combustion engine (110) is transferred to the internal combustion engine (11).
3. The starting assist device for the internal combustion engine according to claim 2, wherein the auxiliary power is supplied to the intake side of 0). 5. The amount of exhaust gas supplied to the intake side of the internal combustion engine (110) after the temperature of the catalyst (115) exceeds a predetermined temperature, the exhaust gas being discharged from the internal combustion engine (110). 5. The start-up assist device for an internal combustion engine according to claim 4, wherein the adjustment is based on an exhaust gas recirculation control for reducing nitrogen oxides therein. 6. The carbon dioxide removing means (127) comprises:
The internal combustion engine according to any one of claims 1 to 5, wherein the internal combustion engine comprises a carbon dioxide absorbent that absorbs carbon dioxide at a predetermined temperature or lower and releases carbon dioxide at a temperature higher than the predetermined temperature. Engine starting aid. 7. The temperature at which the carbon dioxide absorber begins to release carbon dioxide is at least the internal combustion engine (110).
The starting aid for an internal combustion engine according to claim 6, wherein the temperature is lower than the maximum temperature of the exhaust gas supplied to the intake side of the engine. 8. The carbon dioxide removing means (127) comprises:
A separation membrane for separating and extracting carbon dioxide, further comprising discharging the carbon dioxide separated and extracted by the carbon dioxide removing means (127) into the atmosphere. A starting aid device for an internal combustion engine as described above.