WO2021203641A1

WO2021203641A1 - Diesel engine exhaust gas aftertreatment system and heating method therefor

Info

Publication number: WO2021203641A1
Application number: PCT/CN2020/118227
Authority: WO
Inventors: 胡仁静
Original assignee: 天纳克（苏州）排放系统有限公司
Priority date: 2020-04-10
Filing date: 2020-09-28
Publication date: 2021-10-14
Also published as: CN113513391A

Abstract

A diesel engine exhaust gas aftertreatment system, comprising an exhaust gas aftertreatment package (1), a power supply (2), a control unit (3), and a coil heating device (4). The exhaust gas aftertreatment package (1) comprises an exhaust gas inlet (11), an exhaust gas outlet (12), and a metal plate (13) to be heated between the exhaust gas inlet (11) and the exhaust gas outlet (12); the power supply (2) is connected to the control unit (3), and supplies the control unit (3) with power required for the operation thereof; the control unit (3) is connected to the coil heating device (4), and the coil heating device (4) is installed on said metal plate (13); when said metal plate (13) needs to be heated, the control unit (3) transmits an alternating voltage signal to the coil heating device (4), so that the coil heating device (4) generates an eddy current effect on said metal plate (13), so as to increase the temperature of said metal plate (13).

Description

Diesel engine exhaust gas aftertreatment system and heating method thereof

This application claims the priority of a Chinese patent application whose application date is April 10, 2020, the application number is 202010276754.5, and the invention title is "Diesel Engine Exhaust Aftertreatment System and Heating Method", the entire content of which is incorporated by reference In this application.

Technical field

The invention relates to a diesel engine exhaust gas aftertreatment system and a heating method thereof, and belongs to the technical field of diesel engine exhaust gas aftertreatment.

Background technique

The diesel engine exhaust aftertreatment system is used to treat the exhaust gas emitted by the diesel engine. With the continuous upgrading of national emission regulations, the requirements for the treatment of harmful substances in the exhaust gas are also getting higher and higher. As a typical technical route, in order to reduce the concentration of harmful substances, it is necessary to increase the amount of urea solution injected into the exhaust gas. The challenge of this technical route is that when the injection volume of urea is increased, it is easy to cause the problem of urea crystallization. Those skilled in the art know that temperature has an important influence on urea crystallization, and the lower the temperature, the greater the risk of urea crystallization. Therefore, in order to reduce urea crystallization, the temperature needs to be increased.

Currently, there are two technologies of heating wire heating and fuel combustion furnace heating. Among them, the heating response of the heating wire is slow, the laying is inflexible, the area is large, and the energy consumption is large; the heating technology of the fuel combustion furnace requires additional fuel (such as diesel, etc.), which will be extra Exhaust gas pollutants are generated, and the installation is not flexible, and the cost is high.

Therefore, it is necessary to design a new type of diesel engine exhaust aftertreatment system and its heating method.

Summary of the invention

The purpose of the present invention is to provide a diesel engine exhaust gas aftertreatment system and a heating method that is easy to install and low in cost.

In order to achieve the above objective, the present invention adopts the following technical solutions: a diesel engine exhaust aftertreatment system, which includes an exhaust aftertreatment package, a power supply, a control unit and a coil heating device, the exhaust aftertreatment package includes an exhaust inlet 1. An exhaust outlet and a metal plate to be heated located between the exhaust inlet and the exhaust outlet, wherein: the power supply is connected to the control unit to supply the control unit with power required for its work; The control unit is connected to the coil heating device, and the coil heating device is installed on the metal plate to be heated; when the metal plate to be heated needs to be heated, the control unit transmits an alternating voltage signal to the The coil heating device causes the coil heating device to generate an eddy current effect on the metal plate to be heated, thereby increasing the temperature of the metal plate to be heated.

As a further improved technical solution of the present invention, the coil heating device is in contact with the metal plate to be heated.

As a further improved technical solution of the present invention, the coil heating device does not contact the metal plate to be heated.

As a further improved technical solution of the present invention, the diesel engine exhaust aftertreatment system further includes a sensor signal line connecting the coil heating device and the control unit to feed back the temperature of the metal plate to be heated to the control unit.

As a further improved technical solution of the present invention, the exhaust gas aftertreatment package includes a diesel catalytic oxidizer (DOC), a diesel particulate filter (DPF) located downstream of the diesel catalytic oxidizer (DOC), and a diesel particulate filter (DPF) located downstream of the diesel catalytic oxidizer (DOC). A selective catalytic reductant (SCR) downstream of the trap (DPF) and a mixer between the diesel particulate trap (DPF) and the selective catalytic reductant (SCR).

As a further improved technical solution of the present invention, the power source is a battery or a generator.

As a further improved technical solution of the present invention, the control unit is an automotive electronic control unit (ECU).

As a further improved technical solution of the present invention, the coil heating device includes a DC coil for receiving alternating voltage signals.

The present invention also relates to a heating method of a diesel engine exhaust aftertreatment system. The heating method includes the following steps:

S1: Determine whether the metal plate to be heated needs to be heated;

S2: When it is determined that heating is required, the control unit transmits an alternating voltage signal to the coil heating device. The coil heating device generates an alternating magnetic field in a direction perpendicular to the metal plate to be heated. The magnetic field generates an eddy current effect on the metal plate to be heated, so that the metal plate to be heated generates an eddy current and releases Joule heat, so as to increase the temperature of the metal plate to be heated.

As a further improved technical solution of the present invention, the heating method further includes the following steps:

S3: Feed back the temperature of the metal plate to be heated to the control unit.

Compared with the prior art, the present invention realizes heating by arranging a coil heating device and using electromagnetic eddy current heating technology, which is easy to install and has a lower cost.

Description of the drawings

Fig. 1 is a schematic diagram of a diesel engine exhaust gas aftertreatment system of the present invention.

Figure 2 is a schematic diagram of eddy current heating.

Detailed ways

Please refer to FIG. 1 and FIG. 2, the present invention discloses a diesel engine exhaust gas aftertreatment system, which includes an exhaust gas aftertreatment package 1, a power source 2, a control unit 3, and a coil heating device 4. The exhaust after-treatment package 1 includes an exhaust inlet 11, an exhaust outlet 12, and a metal plate 13 to be heated between the exhaust inlet 11 and the exhaust outlet 12. The metal plate 13 to be heated may be the shell of the exhaust post-treatment package 1 or any shell that needs to be heated. The power supply 2 is connected to the control unit 3 and supplies the control unit 3 with power required for its operation. The control unit 3 is connected to the coil heating device 4, and the coil heating device 4 is installed on the metal plate 13 to be heated. When the metal plate 13 to be heated needs to be heated, the control unit 3 transmits an alternating voltage signal to the coil heating device 4 so that the coil heating device 4 generates an eddy current effect on the metal plate 13 to be heated. Thus, the temperature of the metal plate 13 to be heated is increased. The coil heating device 4 may be in contact with the metal plate 13 to be heated, or the coil heating device 4 and the metal plate 13 to be heated may be separated by a certain distance so that they do not contact. This arrangement improves the installation flexibility of the coil heating device 4 and improves the efficiency.

Specifically, in one embodiment of the present invention, the exhaust gas aftertreatment package 1 includes a diesel catalytic oxidizer (DOC), a diesel particulate filter (DPF) located downstream of the diesel catalytic oxidizer (DOC), A selective catalytic reductant (SCR) located downstream of the diesel particulate trap (DPF) and a mixer between the diesel particulate trap (DPF) and the selective catalytic reductant (SCR) . The metal plate 13 to be heated corresponds to the mixer. Of course, in other embodiments, the metal plate 13 to be heated may be any surface of the exhaust gas post-treatment package 1 that needs to be heated, and is not limited to the mixer part.

In an embodiment of the present invention, the power source 2 is a vehicle-mounted power source, such as a battery or a generator. The control unit 3 is an automotive electronic control unit (ECU). The power supply 2 and the control unit 3 are connected through a first connecting harness 51, and the control unit 3 and the coil heating device 4 are connected through a second connecting harness 52. In addition, the diesel engine exhaust aftertreatment system further includes a sensor signal line 53 connecting the coil heating device 4 and the control unit 3 to feed back the temperature of the metal plate 13 to be heated to the control unit 3. .

In an embodiment of the present invention, the coil heating device 4 includes a DC coil for receiving an alternating voltage signal, such as an iron core coil.

When the diesel engine exhaust after-treatment system performs exhaust gas purification, according to needs, the part of the exhaust after-treatment package 1 (corresponding to the metal plate 13 to be heated) is assisted to heat, so as to facilitate the diesel engine exhaust after-treatment system to treat the exhaust gas. The purification treatment. Specifically, the coil heating device 4 is added to the metal plate 13 to be heated of the package 1 after the exhaust is exhausted. The shape of the coil heating device 4 is not limited, and can be flexibly designed according to actual needs. Then, a temperature sensor connected to the sensor signal line 53 is attached directly below the DC coil to monitor the temperature of the metal plate 13 to be heated in real time, so that the temperature is controlled by the control unit 3 within a desired temperature range.

The heating method of the diesel engine exhaust aftertreatment system of the present invention includes the following steps:

S1: Determine whether the metal plate 13 to be heated needs to be heated;

S2: When it is determined that heating is required, the control unit 3 transmits an alternating voltage signal to the coil heating device 4, and the coil heating device 4 generates an alternating magnetic field in a direction perpendicular to the metal plate 13 to be heated The alternating magnetic field generates an eddy current effect on the metal plate 13 to be heated, so that the metal plate 13 to be heated generates an eddy current, releases Joule heat, so as to increase the temperature of the metal plate 13 to be heated.

Specifically, please refer to FIG. 2, the control unit 3 transmits a variable frequency alternating voltage U _i to the coil heating device 4, the coil heating device 4 generates a current I ₁ , and the coil heating device 4 _{An alternating magnetic field H 1} (for example, a controlled alternating magnetic field) is generated along the direction of the direct current coil in the device perpendicular to the metal plate 13 to be heated. The controlled alternating magnetic field H ₁ generates an eddy current effect on the metal plate 13 to be heated, generates an induced magnetic field H ₂ _{opposite to the direction of the alternating magnetic field H 1} , and generates an alternating current I ₂ (ie, eddy current), which releases a large amount of (The formula is Q=I ₂ ² *R*T, where Q represents Joule heat, I ₂ represents the aforementioned alternating current, R represents resistance, and T represents time), and finally achieves the purpose of heating. There is a height X between the coil heating device 4 and the metal plate 13 to be heated, and the height X can be adjusted.

The heating method also includes the following steps:

S3: Feed back the temperature of the metal plate 13 to be heated to the control unit 3.

Compared with the prior art, the present invention realizes heating by installing a coil heating device 4 and using electromagnetic eddy current heating technology, which is easy to install, low cost, fast heating response, and does not generate additional waste gas pollutants due to heating itself.

The above embodiments are only used to illustrate the present invention and not to limit the technical solutions described in the present invention. The understanding of this specification should be based on those skilled in the art, although this specification has already described the present invention in detail with reference to the above embodiments. Note, however, those of ordinary skill in the art should understand that those skilled in the art can still modify or equivalently replace the present invention, and all technical solutions and improvements that do not depart from the spirit and scope of the present invention should be covered in Within the scope of the claims of the present invention.

Claims

An exhaust gas aftertreatment system for a diesel engine, which is characterized in that it includes an exhaust gas aftertreatment package, a power supply, a control unit, and a coil heating device. The exhaust gas aftertreatment package includes an exhaust gas inlet, an exhaust gas outlet, and an exhaust gas outlet. The metal plate to be heated between the air inlet and the exhaust outlet, wherein: the power supply is connected to the control unit to supply the control unit with power required for its work; the control unit and the coil heat The device is connected, the coil heating device is installed on the metal plate to be heated; when the metal plate to be heated needs to be heated, the control unit transmits an alternating voltage signal to the coil heating device to heat the coil The device generates an eddy current effect on the metal plate to be heated, thereby increasing the temperature of the metal plate to be heated.
The diesel engine exhaust aftertreatment system according to claim 1, wherein the coil heating device is in contact with the metal plate to be heated.
The diesel engine exhaust aftertreatment system according to claim 1, wherein the coil heating device does not contact the metal plate to be heated.
The diesel engine exhaust aftertreatment system according to claim 1, wherein the diesel engine exhaust aftertreatment system further comprises a sensor signal line connecting the coil heating device and the control unit to connect the The temperature of the metal plate to be heated is fed back to the control unit.
The diesel engine exhaust after-treatment system according to claim 1, wherein the exhaust after-treatment package includes a diesel catalytic oxidizer (DOC), a diesel particulate trap located downstream of the diesel catalytic oxidizer (DOC) Filter (DPF), a selective catalytic reductant (SCR) located downstream of the diesel particulate trap (DPF), and a selective catalytic reductant (SCR) located downstream of the diesel particulate filter (DPF) and the selective catalytic reductant (SCR) The mixer between.
The diesel engine exhaust aftertreatment system according to claim 1, wherein the power source is a battery or a generator.
The diesel engine exhaust aftertreatment system according to claim 1, wherein the control unit is an automotive electronic control unit (ECU).
The diesel engine exhaust aftertreatment system according to claim 1, wherein the coil heating device includes a DC coil for receiving an alternating voltage signal.
A heating method for a diesel engine exhaust aftertreatment system according to any one of claims 1 to 8, the heating method comprising the following steps:

S1: Determine whether the metal plate to be heated needs to be heated;

S2: When it is determined that heating is required, the control unit transmits an alternating voltage signal to the coil heating device. The coil heating device generates an alternating magnetic field in a direction perpendicular to the metal plate to be heated. The magnetic field generates an eddy current effect on the metal plate to be heated, so that the metal plate to be heated generates an eddy current and releases Joule heat, so as to increase the temperature of the metal plate to be heated.
9. The heating method of claim 9, wherein the heating method further comprises the following steps:

S3: Feed back the temperature of the metal plate to be heated to the control unit.