JPH03225012A - Exhaust trap regeneration device for diesel engines - Google Patents

Abstract

PURPOSE:To easily raise the exhaust gas temperature nearly in proportion to the raising value of the intake air temperature by installing a means for heating the intake air temperature by the exhaust gas heat. CONSTITUTION:A warming air chamber 9 is formed on the outer periphery of an exhaust trap case 8a, and an intake inlet pipe 12 opened to the atmosphere and a warm air intake pipe 13 which communicates to the suction pipe 14 of an air cleaner 7 are installed in the warm air chamber 9. A warm air opening/closing valve 15 is installed in the warm air intake pipe 13, and an intake opening/closing valve 16 is installed in the suction pipe 14. A controller 19 opens the warm air opening/closing valve 15 when the exhaust trap 8 is in regeneration, and closes the intake opening/closing valve 16. Accordingly, when the exhaust trap 8 is in regeneration, the intake air which is heated at a high temperature in the warm air chamber 9 is introduced into an engine, and also the combustion in the engine is carried out at a high temperature, and also the exhaust gas temperature rises in proportion. The black smoke which clogs the exhaust trap 8 is combusted again by the exhaust gas at a high temperature, and discharged, and then the exhaust trap 8 can be recovered.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a regeneration device for an exhaust particulate trap used in an exhaust purification device for a diesel engine.

[Conventional technology]

In the conventional exhaust purification device for a diesel engine, in the case of an engine with a turbo supercharger as shown in FIG. 6, an exhaust trap 52 connected to an exhaust pipe 51 is installed, and the inside of the exhaust trap 52 contains the exhaust gas discharged from the engine. A ceramic honeycomb coated with platinum, rhodium, baladium, etc. is used as a catalyst that has the function of purifying harmful exhaust gas and black smoke (particulate). Harmful exhaust gases such as C09HC are oxidized by metal catalysts such as platinum, rhodium, and palladium, rendered harmless, and discharged into the outside air. At the same time, black smoke is collected using a ceramic honeycomb filter to prevent black smoke from being discharged into the outside air. I know. However, with ceramic honeycomb, the exhaust gas temperature is low when starting frequently or during continuous light load operation.
Because the collected black smoke cannot be combusted, if it is operated for a long period of time, it becomes clogged, preventing the release of exhaust gas, increasing exhaust pressure and temperature, and causing burnout of intake and exhaust valves and pistons, and exhaust traps. Burnout occurs due to overheating.

Therefore, in order to prevent the above-mentioned problems, an exhaust trap regeneration device is provided. Conventional embodiments of these will be described. An exhaust pressure sensor 19 and an exhaust temperature sensor 20 are provided in the conduit on the inlet side of the exhaust trap 52 shown in FIG. 6 to form an exhaust trap.

The clogging condition of the tap 52 is detected. These detection signals are inputted to the controller 55 of the control unit by the signal circuits 53 and 54, and the controller 55 performs arithmetic processing for determination, and the I control signal is sent to the actuator 57 via the signal circuit 56. intake opening/closing valve 58
It is configured to operate.

During exhaust trap regeneration, the amount of intake air is slightly throttled by the intake opening/closing valve 58, reducing the amount of intake air and significantly lowering the excess air ratio to create a poor combustion state, increasing the exhaust temperature and exhaust output of exhaust gas. , the black smoke clogging the ceramic honeycomb in the exhaust trap 55 is removed temporarily (20 to 3
(about 0 minutes) is incinerated and discharged into the outside air for regeneration.

Although not shown, there is an exhaust purification device for an automobile engine disclosed in Japanese Patent Application Laid-Open No. 115809/1983. This is equipped with a trap regeneration burner inside the exhaust trap that incinerates the black smoke collected in the exhaust trap, and uses the differential pressure across the exhaust trap to incinerate and regenerate the black smoke that clogs the exhaust trap. has been done.

[Problem to be solved by the invention]

However, in such a conventional exhaust trap regeneration device, the intake air amount is throttled as shown in Fig. 6. Especially in a supercharged engine, if the intake air is continued to be throttled for 20 to 30 minutes, supercharging will occur. The pressure on the back side of the blower impeller on the blower side of the machine decreases, and the pressure on the center housing side, which supports the bearing and forms the lubricating oil chamber, is reversed, and the lubricating oil in the center housing is sucked into the blower side. , there is a problem of oil leakage to the blower side. In addition, in the regeneration burner system used in automobiles, the cost of the burner combustion device and burner control device is high, and the burner nozzle is installed in high-temperature exhaust gas during normal operation. Therefore, there are problems such as lack of durability and reliability, and the need for periodic maintenance.

Therefore, the present invention was made to solve this problem.Generally, in a diesel engine, the relationship between the intake air temperature and exhaust temperature of the engine is such that the ratio of increase in intake air temperature to the corresponding increase in exhaust temperature is approximately 1. :1.2
It is known that this is the case, and the present invention is intended to serve as an exhaust trap regeneration means by increasing the intake air temperature and increasing the exhaust gas temperature only during exhaust trap regeneration.

[! Means for Solving the Problem] In order to achieve the above object, the first present invention provides a means for heating the intake air temperature with heat of exhaust gas discharged from the engine, and specifically, a means for heating the intake air temperature with exhaust gas heat discharged from the engine. A warm air chamber is formed on the outer periphery of the warm air chamber, an intake inlet pipe is provided that opens to the atmosphere of the warm air chamber, a warm air intake pipe is provided that communicates the warm air chamber with the intake pipe of the air purifier, and the warm air intake pipe is provided with a warm air intake pipe. An on-off valve and an intake on-off valve are provided in the suction pipe of the air purifier, and as means for forcibly opening and closing the warm air on-off valve and the intake on-off valve during exhaust trap regeneration, the inlet side pressure and temperature of the exhaust trap are detected. llaI means is provided for controlling the warm air on/off valve and the intake air on/off valve based on signals from the pressure sensor and temperature sensor.

Furthermore, as a second invention, a warm air chamber is formed on the outer periphery of the intake pipe,
means for providing an exhaust introduction pipe that communicates the warm air chamber with an exhaust pipe on the upstream side of the exhaust trap, including an exhaust on-off valve in the exhaust introduction pipe, and forcibly opening and closing the exhaust on-off valve during exhaust trap regeneration; A control means is provided for controlling the exhaust opening/closing valve based on signals from a pressure sensor and a temperature sensor that detect the pressure and temperature on the inlet side of the exhaust trap.

[For production]

As mentioned above, since the exhaust trap case has a warm air chamber around the outer periphery of the exhaust gas, or a warm air chamber that introduces exhaust gas around the outer periphery of the intake pipe, the inside of the engine is heated to a high temperature when the exhaust trap is regenerated. Since intake air is introduced, the combustion temperature within the engine also becomes high, and the exhaust gas temperature increases accordingly. The exhaust trap can be regenerated by re-burning the black smoke that has clogged the exhaust trap's ceramic comb with this high-temperature exhaust gas, incinerating it, and discharging it.

〔Example〕

Next, the present invention will be explained based on two embodiments shown in the drawings. FIG. 1 shows an embodiment of a diesel engine with an exhaust turbo supercharger. An engine main body 1 has an exhaust manifold 2 and an intake manifold 3, and is connected to an exhaust turbo supercharger 4. The exhaust turbo supercharger is connected to an exhaust pipe 5 on the exhaust side, an intake pipe 6 and an air cleaner 7 on the intake air side.

The exhaust pipe is connected to an exhaust trap 8 on the downstream side, and the exhaust gas is discharged to the outside air from the exhaust pipe 9 on the exit side of the exhaust trap 8. The configuration of the exhaust trap 8 and the warm air chamber for warming the intake air is shown in FIGS. 2A and 2B. A ceramic honeycomb carrier 8b is interposed inside the exhaust trap case 8a shown in FIG. 2A. . This carrier 8b has one part of the honeycomb holes open (18c) and the outlet side 8d closed, and the other part has the inlet side open and the outlet side open, so that the exhaust air can pass through a large wall part. This collects exhaust particulates as they pass through.Exhaust trap case 8
A warm air chamber 9 is formed on the outer periphery of the exhaust trap 8 by welding the joint with the exhaust trap case 8a, and inside the warm air chamber 9, a heat dissipation plate 10 shown in FIG. A large number of them are arranged radially in the longitudinal direction on the wall soil, and serve to enhance the warming effect of the warming room 9.

A warm air chamber case 11 forming a warm air chamber 9 has an intake inlet pipe 1.
2 and a warm air distribution pipe 13 are open and fixed. The warm air distribution pipe 13 is connected to the suction pipe 14 of the air purifier 7 as shown in FIG.
The exhaust trap is connected to the exhaust trap, and when the exhaust trap is regenerated, warmed intake air is drawn into the engine. On the other hand, inside the warm air distribution pipe 13 there is a warm air on/off valve 15 and an intake pipe 14.
An intake opening/closing valve 16 is disposed upstream of the joint of the warm air distribution pipe 13, and the intake opening/closing valve 16 is disposed at the upstream side of the joint of the warm air distribution pipe 13.
5 is opened, the intake opening/closing valve 16 is closed, and the intake air heated in the warm air chamber 9 passes through the air purifier 71 and the exhaust turbo supercharger 4, and the high temperature air is sucked into the engine. , the combustion temperature is increased and the exhaust gas temperature becomes higher to burn out the black smoke deposited on the ceramic honeycomb in the exhaust trap.

A method of operating the warm-up opening/closing valve 15 and the intake opening/closing valve 16 during regeneration of the exhaust trap 8 described above will be explained. Exhaust trap 8
An exhaust pressure sensor 17 for detecting exhaust pressure and an exhaust temperature sensor 18 for detecting exhaust temperature are arranged in the exhaust pipe 5 connected to the The signal is input to the controller 19 via the signal circuit 20 or 21. The controller 19 sends the command circuit 22 or 23 according to the input detection signal.
The actuator 24 or 25 is then commanded to open and close the valve bodies of the warm-up opening/closing valve 15 and the intake opening/closing valve 16. Further, the functions of these 111m devices will be explained using the basic configuration functional blower diagram in FIG. A detection signal from the exhaust temperature sensor or the exhaust pressure sensor is read into the wAa1 section 30, passes through the reading means 31, and is processed by the control valve opening/closing determination means 32 of the warm air on/off valve 15 and the intake on/off valve 16 to open/close the t+1gl valve. A determination is made as to whether or not the operation is possible, and the control valve wit signal generating means 33 issues an operation command signal to the control valve 35 (actuators 24 and 25 in FIG. 1) to operate the control valve. At the same time, a timer means 36 is built into the 14 control section 30, and a preset operating time is controlled.

The above-mentioned operation will be explained with reference to an operation flowchart shown in FIG.

The diesel engine starts operating, and the operating condition is such that the exhaust trap regeneration device can function, and steps P+ and Pg
Alternatively, a detection signal is read from the exhaust pressure or exhaust temperature sensor at Ps or Pa, and compared with a preset TSM valve operation setting value to make a determination, and if it is different from the set value, the process returns to the starting point. Repeat these operations and determinations,
When the exhaust pressure or exhaust temperature reaches the set value, step P;
Then, it is determined whether all the conditions for the regeneration operation are satisfied, and if the conditions are satisfied, the control valve opening/closing operation is performed in step P based on the control valve operation command.

At the same time, the control valve operating time is set by a timer, and in step P, the passage of the am valve operating set time is counted, and when the set time is reached, a command is issued in step P to return the control valve to the normal state. , the control function returns to normal processing. Furthermore, another embodiment is shown in FIG. 5 and will be described.

In the present invention, as in the above-described embodiment, a warm air distribution pipe 41 is fixed to the exhaust pipe 5 connected to the exhaust trap 40 as a means for heating the intake air temperature with exhaust gas heat to warm the air. is fixedly installed so as to open into a warm air chamber 42 formed in the intake pipe 6 which communicates with the air purifier 7 and the exhaust turbo supercharger 4. .

A warm air opening/closing valve 43 is provided in the warm air distribution pipe 41,
As shown and explained in FIG. 1, the exhaust pipe 5 is provided with an exhaust pressure sensor 17 and an exhaust temperature sensor 18 for detecting exhaust pressure and exhaust temperature, and these detection signals are input to the controller 44 of the aai section. is processed, a command signal for operation is sent to the actuator 44, and the warm-up valve 43 is activated.
is operated, and the exhaust trap is regenerated in the same manner as in the invention shown in FIG.

As mentioned above, the exhaust trap regenerator is controlled and functions, but the exhaust pressure and exhaust temperature are adjusted as required.

The timer operation time can be set arbitrarily.

〔Effect of the invention〕

As explained above, according to the present invention, the combustion temperature is increased by increasing the intake air temperature of the engine to a high temperature, and the exhaust gas temperature is easily reduced in approximately proportion to the increase in the intake air temperature. It is now possible to rise and burn the black smoke that has accumulated in the ceramic honeycomb of the exhaust trap,
It becomes possible to exhaust it to the outside air. Moreover, on the other hand, oil leakage from the blower side of the exhaust turbo supercharger, which is a problem in the prior art, is prevented from occurring, and the device of the present invention can be easily manufactured at low cost.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an sga device according to an embodiment of the present invention, and FIG.
Figures A and B are detailed views of the warm air chamber fixed to the exhaust trap of the present invention, 3rd V! J is the basic configuration functional block diagram, 4th
v! J is an operation chart, FIG. 145 is a diagram showing a control device of another embodiment, and FIG. 6 is a conventional exhaust trap regeneration v
The figure which shows the control device of LW. l... Engine body 2... Exhaust manifold 3...
...Intake manifold 4...Exhaust turbo supercharger 8.40...Exhaust trap 9.42...Warm chamber 15.43 ... Warm-up on-off valve 16 ... Intake on-off valve I7 ... Exhaust pressure sensor I8 ...
...Exhaust temperature sensor 19.44...Controller 24.25.45...Actuator diagram (A) diagram (B)

Claims (5)

[Claims] (1) In an engine equipped with an exhaust trap installed in the exhaust passage to collect particulates in the exhaust gas, the engine is equipped with a warm air chamber that is heated by exhaust gas, and the warm air chamber warms intake air to create a high temperature inside the engine. An exhaust trap regeneration device for a diesel engine, characterized by having a means for supplying air. (2) In claim 1, a warm air chamber surrounding the outer periphery of the exhaust trap case is formed, an intake inlet pipe opening to the atmosphere is provided on the outer periphery of the warm air chamber, and an engine is provided on the outer periphery opposite the intake inlet pipe. An opening of a warm air intake pipe communicating with the intake pipe of the air purifier is provided, and a warm air on/off valve is provided in the warm air intake pipe, and an opening is provided on the upstream side of the contact part of the intake pipe of the air purifier with the warm air intake pipe. and an intake opening/closing valve, and means for forcibly opening and closing the valve body of the warm air opening/closing valve during exhaust trap regeneration, and means for opening and closing the valve body of the intake opening/closing valve. The exhaust trap regeneration device for a diesel engine according to claim 1. (3) In the warm air on/off valve and the intake on/off valve according to claim 2, the valve body of the warm air on/off valve is 3. The exhaust trap regeneration device for a diesel engine according to claim 1, further comprising a control means for determining and operating the opening/closing means of the valve body of the intake opening/closing valve. (4) In claim 1, a warm air chamber surrounding the outer periphery of the intake pipe is formed, and an exhaust introduction pipe is provided that communicates the warm air chamber with an exhaust pipe on the upstream side of the exhaust trap. 2. The exhaust trap regeneration device for a diesel engine according to claim 1, further comprising an exhaust on-off valve and means for opening and closing the exhaust on-off valve emphatically during exhaust trap regeneration. (5) In the exhaust on-off valve according to claim 4, means for opening and closing the valve body of the exhaust on-off valve based on signals from a pressure sensor and a temperature sensor that detect the inlet side pressure or the inlet side temperature of the exhaust trap. 5. The exhaust trap regeneration device for a diesel engine according to claim 1, further comprising control means for determining and operating the exhaust trap regeneration device for a diesel engine.