JP2018197534A - Exhaust emission control device and control device - Google Patents

Abstract

To provide an exhaust emission control device which can prevent deterioration of fuel consumption, and to provide a control device.SOLUTION: An exhaust emission control device includes: a filter which collects a particulate substance contained in exhaust gas from an internal combustion engine and is regenerated by the collected particulate substance being burned; an inter-cooler which cools intake air led to the internal combustion engine; and an intake air temperature adjustment part which leads exhaust heat around the internal combustion engine to a periphery of the inter-cooler to adjust a temperature of the intake air. For example, the intake air temperature adjustment part is disposed between the internal combustion engine and the inter-cooler and has a fan which blows the exhaust heat around the internal combustion engine to the periphery of the inter-cooler.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to an exhaust purification device and a control device.

  Conventionally, as a filter for collecting particulate matter (hereinafter referred to as PM) contained in exhaust gas from an internal combustion engine, for example, a diesel particulate filter (hereinafter referred to as DPF) is known. Yes.

  When PM accumulates to some extent in the DPF, it is necessary to regenerate the DPF by raising the temperature of the exhaust gas.

JP 2009-108700 A

  By the way, the temperature of the exhaust gas is low during idling of the engine, during low-speed running, and during no-load operation (hereinafter collectively referred to as low-load operation). The lower the exhaust temperature, the more fuel consumed to raise the temperature of the exhaust gas.

  An object of the present disclosure is to provide an exhaust emission control device and a control device that can prevent deterioration in fuel consumption.

An exhaust emission control device of the present disclosure includes:
A filter that collects particulate matter contained in exhaust gas from the internal combustion engine and is regenerated by burning the collected particulate matter;
An intercooler for cooling the intake air led to the internal combustion engine;
An intake air temperature adjusting unit that adjusts the temperature of the intake air by guiding exhaust heat around the internal combustion engine to the periphery of the intercooler;
Is provided.

  The control device according to the present disclosure is the above-described exhaust gas purification device, wherein the intake air temperature adjustment unit adjusts the intake air temperature when the internal combustion engine is in a low load operation and the filter is regenerated. To control.

  According to the present disclosure, it is possible to prevent deterioration of fuel consumption.

The block diagram which shows an example of a structure of the internal combustion apparatus which concerns on one embodiment of this indication Front view conceptually showing an internal combustion engine according to the present embodiment The figure which shows an example of the regeneration process of DPF of the internal combustion engine in this Embodiment The block diagram which shows an example of a structure of the internal combustion apparatus which concerns on the modification of this Embodiment.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
In the present embodiment, a case where the present invention is applied to a diesel engine (internal combustion engine) mounted on an automobile will be described.

  First, a schematic structure of a diesel engine (hereinafter simply referred to as an engine) according to the present embodiment will be described. FIG. 1 is a schematic configuration diagram of an engine 1 according to the embodiment.

  As shown in FIG. 1, the engine 1 includes an intake manifold 11, an exhaust manifold 12, a turbocharger 13, an air cleaner 17, an intercooler 18, an exhaust pipe 20, an exhaust passage 30, a temperature sensor 37, a radiator 40, and an intake air temperature adjustment unit 50. Is provided. Further, there is provided an ECU 100 (corresponding to the “control device” of the present invention) for comprehensively controlling the operation of the engine 1 using an electrical auxiliary device (including the intake air temperature adjustment unit 50). It has been.

  The intake manifold 11 is connected to an intercooler 18 via a downstream intake pipe 16b. The intercooler 18 is connected to the compressor 14 of the turbocharger 13 via the intake pipe 16. The compressor 14 is connected to an air cleaner 17 via an upstream side intake pipe 16a.

  The intake air from the air cleaner 17 is sucked into the compressor 14 through the upstream side intake pipe 16a and boosted, cooled through the intercooler 18, and supplied from the intake manifold 11 to the engine 1 through the downstream side intake pipe 16b. Is done. The path from the air cleaner 17 to the intake manifold 11 may be referred to as an “intake system”.

  The exhaust manifold 12 is connected to the turbine 15 of the turbocharger 13.

  The turbine 15 is connected to the exhaust pipe 20 via the exhaust passage 30. The exhaust gas from the engine 1 drives the turbine 15 and then is exhausted to the exhaust pipe 20 through the exhaust passage 30.

  An oxidation catalyst (Diesel Oxidation Catalyst: DOC) 31 and a diesel particulate filter (Diesel particulate filter: DPF) 32 are provided in the exhaust passage 30.

  The DOC 31 is a catalyst that oxidizes carbon monoxide (CO) and hydrocarbon (HC) contained in the exhaust gas.

  The DPF 32 is a filter that collects particulate matter (PM) contained in the exhaust gas. The PM collected in the DPF 32 is burned by raising the temperature of the exhaust gas. Thereby, the DPF 32 is regenerated. In the following description, burning the collected PM is referred to as regeneration of the DPF 32.

  When the engine 1 is operated at a low load, the temperature of the exhaust gas is low. When the temperature of the exhaust gas is low, consuming a large amount of fuel in order to raise the temperature of the exhaust gas during regeneration of the DPF 32 causes a deterioration in fuel consumption.

  In the present embodiment, the intake air supplied to the engine 1 is heated to increase the temperature of the exhaust gas when the DPF 32 is regenerated.

  As shown in FIG. 1, the radiator 40 is disposed between the engine 1 and the intercooler 18. The coolant of the engine 1 is conveyed to the radiator 40. The radiator 40 is a heat exchanger that cools the conveyed coolant by heat exchange with outside air.

  As shown in FIG. 1, the cooling circuit 41 is provided with a bypass passage 42 that bypasses the radiator 40. Thereby, the coolant W circulates in the order of the water pump 43, the engine 1, the thermostat 44, and the radiator 40. The coolant W circulates in the order of the water pump 43, the engine 1, the thermostat 44, and the bypass passage 42.

FIG. 2 is a front view conceptually showing the engine 1.
As shown in FIG. 2, the intake air temperature adjustment unit 50 includes a fan 60, a motor 62, and an electromagnetic clutch (not shown).

  As shown in FIG. 1, the fan 60 is disposed between the engine 1 and the radiator 40. In this embodiment, the fan 60 is a cooling fan for allowing outside air to pass through the radiator 40.

  As shown in FIG. 2, the fan 60 rotates in the clockwise direction D1 when the motor 62 is rotated forward, and rotates in the counterclockwise direction D2 when the motor 62 is reversed.

  The electromagnetic clutch transmits / cuts power from the motor 62 to the fan 60.

  When the fan 60 rotates in the clockwise direction D1, the blowing direction of the fan 60 is the direction B1 (see FIG. 1) toward the engine 1. That is, when the fan 60 rotates in the clockwise direction D1, the outside air passes through the radiator 40 and is pulled to the engine 1 side. Thereby, the coolant of the engine 1 is cooled by the outside air.

  When the fan 60 rotates in the counterclockwise direction D2, the blowing direction of the fan 60 is the direction toward the radiator 40, and further, the direction B2 toward the intercooler 18 ahead (see FIG. 1). That is, the fan 60 blows high-temperature air (exhaust heat) around the engine 1 to the periphery of the intercooler 18 when rotating in the counterclockwise direction D2. Thereby, the intercooler 18 is heated by exhaust heat. As a result, the intake air supplied to the engine 1 is heated.

  Next, the ECU 100 will be described.

  The ECU 100 includes a microcomputer including a CPU, a ROM, a RAM, and the like (not shown) and an input / output circuit. A differential pressure sensor 36 and a temperature sensor 37 are connected to the input circuit of the ECU 100. An intake air temperature adjusting unit 50 (motor 62) is connected to the output circuit of the ECU 100.

  The differential pressure sensor 36 detects a pressure difference between the upstream side and the downstream side of the DPF 32 in the exhaust passage 30.

  As shown in FIG. 1, the temperature sensor 37 is provided on the outlet side of the engine 1 in the cooling circuit 41. The temperature sensor 37 detects the temperature of the coolant in the engine 1. The temperature of the coolant may be detected by providing the temperature sensor 37 in the radiator 40 or in the coolant passage 45 (see FIG. 1) that connects the engine 1 and the radiator 40.

  The ECU 100 includes an exhaust purification device control unit 101 and a temperature adjustment control unit 102 as shown in FIG.

  The exhaust purification device control unit 101 estimates the amount of PM collected by the DPF 32 based on the detection result of the differential pressure sensor 36. The exhaust emission control device control unit 101 determines whether to regenerate the DPF 32 based on the estimated amount of collected PM.

  The exhaust emission control device control unit 101 determines whether or not the engine 1 is in a low load operation based on, for example, the vehicle speed, the engine speed, and the fuel injection amount.

  Based on the detection result of the temperature sensor 37, the exhaust purification device control unit 101 determines whether the temperature of the coolant exceeds a predetermined threshold value.

  When the engine 1 is in a low load operation and the DPF 32 is regenerated, the temperature adjustment control unit 102 rotates the fan 60 in the counterclockwise direction D2 so that the air blowing direction of the fan 60 is intercooler 18. The intake air temperature adjustment unit 50 (motor 62) is controlled so as to be in the direction B2 toward the. Thereby, the exhaust heat around the engine 1 is blown to the periphery of the intercooler 18. As a result, since the intercooler 18 is heated by the exhaust heat, the intake air is heated.

  In cases other than the above, the temperature adjustment control unit 102 rotates the fan 60 in the clockwise direction D1 to control the intake air temperature adjustment unit 50 so that the blowing direction of the fan 60 becomes the direction B1 toward the engine 1. To do. As a result, outside air passes through the radiator 40 and is pulled to the engine 1. As a result, the coolant of the engine 1 is cooled.

  Even when the engine 1 is in a low-load operation and the DPF 32 is regenerated, the temperature adjustment control unit 102 determines that the fan 60 is in a state where the coolant temperature of the engine 1 exceeds a predetermined threshold value. The intake air temperature adjusting unit 50 is controlled so that the air blowing direction is the direction B1 toward the engine 1. Thereby, it can suppress that the temperature of a cooling fluid rises from a predetermined threshold value.

<DPF 32 regeneration process>
Next, an example of the regeneration process of the DPF 32 will be described with reference to FIG. The regeneration process of the DPF 32 is started when the engine 1 is started. Hereinafter, the exhaust purification device control unit 101 and the temperature adjustment control unit 102 will be described as the ECU 100.

  In step S100, the ECU 100 determines whether or not the engine 1 is in a low load operation. In the case of low load operation (step S100: YES), the process proceeds to step S110. If it is not during the low load operation of the engine 1 (step S100: NO), the process proceeds to step S140.

  In step S110, the ECU 100 determines whether or not the DPF 32 is to be regenerated.

  When the DPF 32 is regenerated (step S110: YES), the process proceeds to step S120. When the DPF 32 is not regenerated (step S110: NO), the process proceeds to step S140.

  In step S120, the ECU 100 determines whether or not the temperature of the coolant of the engine 1 exceeds a threshold value. When the temperature of the coolant exceeds the threshold (step S120: YES), the process proceeds to step S140. When the temperature of the coolant does not exceed the threshold (step S120: NO), the process proceeds to step S130.

  In step S130, the ECU 100 controls the intake air temperature adjustment unit 50 (the motor 62) so that the blowing direction of the fan 60 is the direction B2 toward the intercooler 18.

  In step S140, the ECU 100 controls the intake air temperature adjusting unit 50 so that the blowing direction of the fan 60 is the direction B1 toward the engine 1.

<Effects of the present embodiment>
As described above, the exhaust gas purification apparatus according to the present embodiment is disposed between the engine 1 and the intercooler 18 and adjusts the temperature of the intake air by guiding the exhaust heat around the engine 1 to the periphery of the intercooler 18. An intake air temperature adjustment unit 50 that controls the intake air temperature adjustment unit 50 to adjust the intake air temperature when the engine 1 is in a low-load operation and the DPF 32 is regenerated. . As a result, the temperature of the intake air rises when the DPF 32 is regenerated. As a result, the temperature of the exhaust gas rises and less fuel is consumed to raise the temperature of the exhaust gas, so that the fuel consumption can be prevented from deteriorating.

  A cooling fan is used as the fan 60. Thereby, since it is not necessary to provide the fan 60 newly, compared with the case where the fan 60 is newly provided, it becomes easy to mount the intake air temperature adjustment part 50 in a vehicle.

<Modification of the present embodiment>
Next, a modification of the present embodiment will be described. In the modification, the configuration different from the above embodiment will be mainly described, and the description of the same configuration will be omitted.

(Modification 1)
First, Modification 1 will be described with reference to FIG. In FIG. 4, the cooling circuit 41 (see FIG. 1) is omitted.
In the above embodiment, the temperature adjustment control unit 102 controls the intake air temperature adjustment unit 50 (the motor 62) so as to adjust the temperature of the intake air by changing the blowing direction of the fan 60.

  On the other hand, in the first modification, as shown in FIG. 4, the intake air temperature adjustment unit 50A includes a fan 60A and a duct 61A. The duct 61 </ b> A extends from the vicinity of the intercooler 18 to the vicinity of the turbocharger 13. The fan 60A is provided in the duct 61A.

  When the engine 1 is in a low load operation and the DPF 32 is regenerated, the temperature adjustment control unit 102 rotates the fan 60A in the forward direction so that the exhaust heat around the turbocharger 13 is discharged by the duct 61A. The intake air temperature adjusting unit 50A is controlled so as to adjust the temperature of the intake air when the air is blown around 18 and high-temperature air passes through the intercooler 18.

  In other cases, the temperature adjustment control unit 102 controls the intake air temperature adjustment unit 50A so as to stop the rotation of the fan 60A. Thereby, for example, when the vehicle travels, outside air is blown to the turbocharger 13 by the duct 61 </ b> A.

  In the first modification, the temperature adjustment control unit 102 may control the intake air temperature adjustment unit 50A so as to adjust the temperature of the intake air by changing the air flow rate of the fan 60A. Specifically, the temperature adjustment control unit 102 controls the intake air temperature adjustment unit 50A so as to increase the amount of exhaust heat and increase the intake air temperature by increasing the rotational speed of the fan 60A.

  In Modification 1, fan 60A is arranged between engine 1 (turbocharger 13) and intercooler 18 in the direction of air flow in duct 61A. For example, the fan 60A may be disposed between the engine 1 and the intercooler 18 without the duct 61A when the engine 1 and the intercooler 18 are disposed to face each other. .

(Modification 2)
Next, Modification 2 will be described.
As shown in FIG. 1, the DOC 31 is disposed upstream of the DPF 32. The regeneration of the DPF 32 is performed by supplying fuel to the DOC 31, activating the DOC 31, and utilizing the generated heat.

  In the second modification, the temperature adjustment control unit 102 controls the intake temperature adjustment unit 50 (motor 62) so that hot fresh air is drawn into the intake system when fuel is not supplied to the DOC 31. Good. Thereby, the temperature drop of DOC31 by low exhaust temperature is suppressed, and the purification rate of DOC31 with respect to the exhaust gas at the time of fuel injection can be made high by subsequent acceleration etc.

(Modification 3)
Next, Modification 3 will be described.
When a NOx occlusion reduction type catalyst (Lean NOx Traps: LNT) that occludes and reduces nitrogen oxide (NOx) is disposed in the exhaust passage 30, the temperature adjustment control unit 102 reduces the NOx occluded in the LNT. The intake air temperature adjusting unit 50 (motor 62) is controlled so that hot fresh air is drawn into the intake system.

  The LNT occludes NOx in the exhaust gas when the exhaust temperature is the occlusion temperature and the exhaust air-fuel ratio is in a lean state. LNT removes (leaves) the stored NOx from the LNT when the exhaust temperature is a predetermined temperature higher than the storage temperature and the exhaust air-fuel ratio is in a rich state.

  When NOx stored in the LNT is reduced, the exhaust gas temperature can be raised by inhaling high-temperature air, so that less fuel is consumed to reduce NOx.

(Modification 4)
In the above embodiment, the temperature adjustment control unit 102 adjusts the intake air temperature so that hot air is drawn into the intake system when the engine 1 is in a low load operation and the DPF 32 is regenerated. The unit 50 (motor 62) is controlled. The present invention is not limited to this, and the temperature adjustment control unit 102 may control the intake air temperature adjustment unit 50 so that hot air is drawn into the intake system when the DPF 32 is regenerated by manual operation. This can also prevent deterioration in fuel consumption.

  In the above embodiment, an electric cooling fan is used as the fan 60. The present invention is not limited to this, and the fan 60 may be mechanical as long as it can change the air blowing direction during regeneration of the DPF 32 and during normal operation. In the mechanical fan 60, the temperature adjustment control unit 102 changes the rotation direction of the fan 60 between when the engine 1 is in a low load operation and the DPF 32 is regenerated and when it is not. The motor 62 may be controlled.

  Moreover, in the said embodiment, in order to change the ventilation direction of the fan 60, the rotation direction of the fan 60 was changed, However, You may change the direction of the fan 60. FIG.

  Note that the direction of the fan 60 may be changed automatically. Moreover, you may comprise so that the direction of the fan 60 can be changed manually by changing the fan 60. FIG. Thereby, for example, at the time of vehicle maintenance inspection, the DPF 32 can be easily regenerated.

  In the above embodiment, the fan 60 cools the radiator 40. The present invention is not limited to this, and the fan 60 may be an electric fan for cooling the intercooler 18 disposed on the side or lower side of the radiator 40 or above the engine 1. By changing the rotation direction of the electric fan, the intake air can be warmed by guiding the high-temperature air near the engine 1 to the vicinity of the intercooler 18.

  In the above embodiment, the technique for regenerating the DPF 32 has been described. However, the present invention is not limited to this, and can be applied to a technique for regenerating a GPF (Gasoline particulate filter).

  The exhaust emission control device of the present disclosure is useful as a vehicle equipped with a diesel engine that is required to prevent deterioration in fuel consumption.

1 Engine 11 Intake Manifold 12 Exhaust Manifold 13 Turbocharger 14 Compressor 15 Turbine 16 Intake Pipe 16a Upstream Intake Pipe 16b Downstream Intake Pipe 17 Air Cleaner 18 Intercooler 20 Exhaust Pipe 30 Exhaust Passage 31 DOC
32 DPF
36 Differential Pressure Sensor 37 Temperature Sensor 40 Radiator 41 Cooling Circuit 42 Bypass Passage 43 Water Pump 44 Thermostat 45 Coolant Passage 50, 50A Intake Air Temperature Control Unit 60, 60A Fan 61A Duct 62 Motor 100 ECU
101 exhaust purification device control unit 102 temperature adjustment control unit

Claims (8)

A filter that collects particulate matter contained in exhaust gas from the internal combustion engine and is regenerated by burning the collected particulate matter;
An intercooler for cooling the intake air led to the internal combustion engine;
An intake air temperature adjusting unit that adjusts the temperature of the intake air by guiding exhaust heat around the internal combustion engine to the periphery of the intercooler;
An exhaust emission control device.   2. The exhaust emission control device according to claim 1, wherein the intake air temperature adjusting unit includes a fan that is disposed between the internal combustion engine and the intercooler and blows exhaust heat around the internal combustion engine to the periphery of the intercooler.   The exhaust emission control device according to claim 2, wherein the intake air temperature adjusting unit adjusts the temperature of the intake air by changing an air flow rate of the fan.   The exhaust purification device according to claim 2, wherein the fan is a cooling fan for cooling the coolant of the internal combustion engine by passing outside air through a radiator disposed between the fan and the intercooler. .   The exhaust emission control device according to claim 4, wherein the intake air temperature adjusting unit adjusts the temperature of the intake air by changing a blowing direction of the cooling fan.   4. The exhaust emission control device according to claim 1, wherein when the internal combustion engine is in a low load operation and the filter is regenerated, the temperature of the intake air is adjusted. A control device that controls the intake air temperature adjustment unit.   6. The exhaust emission control device according to claim 4, wherein when the internal combustion engine is in a low load operation and the filter is regenerated, exhaust heat around the internal combustion engine is reduced. A control device for controlling the cooling fan so as to blow air around the intercooler. Even when the internal combustion engine is in a low-load operation and the filter is regenerated, when the temperature of the coolant of the internal combustion engine exceeds a predetermined threshold, the outside air is supplied to the radiator. The control device according to claim 7, wherein the cooling fan is controlled to pass.

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