TWI504843B - Apparatus and method for treating exhaust gas from vehicle - Google Patents

Description

Vehicle exhaust gas treatment device and treatment method thereof

The present invention relates to an exhaust gas treatment device and an exhaust gas treatment method, and more particularly to a carrier exhaust gas treatment device and a treatment method therefor.

Among the gases emitted by the operation of the engine, the main components causing air pollution are, for example, particulate matter, nitrogen oxides, hydrocarbons, carbon monoxide, and the like. Among them, nitrogen oxides will oxidize in the atmosphere to form nitrogen dioxide, which is a toxic gas, which not only affects the line of sight, but also induces respiratory diseases and causes damage to the lungs. Therefore, countries around the world are paying more and more attention to the content of nitrogen oxides in exhaust gas, and the relevant emission standards are becoming stricter.

At present, there are many ways to control nitrogen oxides, such as exhaust gas recirculation system, selective reduction catalyst system, water spray cooling, etc., and the selective reduction catalyst system is most effective. A typical selective reduction catalyst system mainly uses ammonia or urea water to chemically react with nitrogen oxides to reduce nitrogen oxides to non-toxic nitrogen and water. Compared with toxic pure ammonia, urea water is not only non-toxic but also highly stable, and easy to store and transport. Therefore, urea selective water is generally used as a reactant in the selective reduction catalyst system.

However, in the past, the selective reduction catalyst system using urea water only assisted the urea water atomization with compressed air, and this method not only requires additional energy, but also increases the burden of the air compressor, and even more affects it. Brake and clutch system actuation. Secondly, compressed air will lower the operating temperature of the system, which may not only induce the expected reaction, but also produce secondary pollution products, which will greatly reduce the conversion efficiency of nitrogen oxides. Furthermore, the urea water remaining in the spray nozzle hole and the periphery of the system tends to evaporate instantaneously due to high temperature to form crystals, which also affects the conversion efficiency of nitrogen oxides.

Therefore, in one aspect of the present invention, a carrier exhaust gas treatment device is provided, wherein a local exhaust gas in an exhaust passage is introduced into a mixing chamber by a drain pipe, thereby effectively preheating the reducing agent and improving the mixing effect, thereby increasing nitrogen oxides. Conversion efficiency.

Secondly, another aspect of the present invention provides a method for treating an exhaust gas of a vehicle by locally introducing the exhaust gas in the exhaust passage into the mixing chamber while sensing the temperature of the exhaust gas in the exhaust passage to start the cooling unit in a timely manner. It can effectively preheat the reducing agent and enhance the mixing effect, thereby improving the conversion efficiency of nitrogen oxides. On the other hand, it can prevent the precipitation of crystals of the reducing agent, and can reduce the mixing chamber and nozzle temperature and reduce the traditional air usage. In order to achieve active thermal management.

According to an embodiment of the structural aspect of the present invention, a carrier exhaust gas treatment device is provided, comprising an exhaust gas passage, a mixing chamber, a nozzle and a reducing agent storage tank. The exhaust passage includes a drainage tube, and the drainage tube has a first end and a second end. The mixing chamber communicates with the exhaust passage, and the nozzle is disposed at one end of the mixing chamber, and the reducing agent reservoir is connected to the nozzle. Wherein the first end of the drainage tube The exhaust passage is connected, and the second end of the drain pipe is connected to the end of the mixing chamber, and the diameter of the first end is larger than the diameter of the second end.

According to an embodiment of the structural aspect of the present invention, the ratio of the diameter of the first end to the diameter of the second end may be 1.5 to 3. The drainage tube and the mixing chamber may have an angle, and the angle may be 110 to 135 degrees. The second end may be disposed on the side wall of the mixing chamber to connect the end of the mixing chamber, and the second end may be tangent to the inner wall of the mixing chamber. The nozzle can be orthogonal to the mixing chamber and the nozzle can have a surface water resistant coating.

According to another embodiment of the structural aspect of the present invention, a carrier exhaust gas treatment device is provided, comprising an exhaust gas passage, a mixing chamber, a temperature sensor, a nozzle, a cooling unit, and a reducing agent storage tank. The exhaust passage includes a drainage tube, and the drainage tube has a first end and a second end. The mixing chamber communicates with the exhaust passage and the temperature sensor senses the temperature within the exhaust passage. The cooling unit is connected to the mixing chamber, the nozzle is disposed at one end of the mixing chamber, and the reducing agent reservoir is connected to the nozzle. Wherein, the first end of the drainage tube is connected to the exhaust passage, and the second end of the drainage tube is connected to the end of the mixing chamber, and the cooling unit is controlled by the temperature sensor. Thereby, the vehicle exhaust gas treatment device can also pass cold air, water mist or heat exchange when the exhaust gas temperature is higher than the reductant crystallization temperature, in addition to effectively preventing the deposition of the reductant crystallized deposit, and also reducing the mixing. Cavity and nozzle temperatures and reduce traditional air usage.

According to another embodiment of the structural aspect of the present invention, the diameter of the first end may be larger than the diameter of the second end, and the ratio of the diameter of the first end to the diameter of the second end may be 1.5 to 3. The drainage tube and the mixing chamber may have an angle, and the angle may be 110 to 135 degrees. The second end may be disposed on the side wall of the mixing chamber to connect the end of the mixing chamber, and the second end may be tangent to the inner wall of the mixing chamber. The nozzle can be orthogonal to the mixing chamber and the nozzle can have a surface water resistant coating.

According to an embodiment of the method aspect of the present invention, a method for treating an exhaust gas of a vehicle is provided, which comprises introducing an exhaust gas in an exhaust gas passage into a mixing chamber by a drainage pipe, wherein the exhaust gas passage, the drainage pipe and the mixing chamber form a path. A reducing agent is injected into the mixing chamber. The temperature of the exhaust gas in the exhaust passage is sensed, and when the temperature of the exhaust gas in the exhaust passage is higher than the crystallization temperature of the reducing agent, a cooling unit is activated to cool the mixing chamber.

According to an embodiment of the method aspect of the present invention, the drainage tube may have a first end and a second end, the first end of the drainage tube may be connected to the exhaust passage, and the second end of the drainage tube may be connected to the mixing chamber, and the first The diameter of the end is larger than the diameter of the second end, and the ratio of the diameter of the first end to the diameter of the second end may be 1.5 to 3. The drainage tube and the mixing chamber may have an angle, and the angle may be 110 to 135 degrees. The reducing agent can be injected into the mixing chamber with a nozzle, and the nozzle can have a surface water resistant coating.

100‧‧‧ Vehicle exhaust gas treatment device

110‧‧‧Exhaust passage

111‧‧‧Drainage tube

111a‧‧‧ first end

111b‧‧‧second end

120‧‧‧Mixed cavity

120a‧‧‧End

130‧‧‧Nozzles

131‧‧‧Surface water resistant coating

140‧‧‧Reducing agent storage tank

150‧‧‧temperature sensor

160‧‧‧Cooling unit

510, 520, 530‧ ‧ steps

D _a , D _b ‧‧‧ caliber

α ‧‧‧ angle

Q ₁ , Q ₂ ‧‧‧ flow

1 is a schematic view showing a vehicle exhaust gas treatment device according to an embodiment of the present invention.

Fig. 2 is a partial plan view showing the vehicle exhaust gas treatment device of Fig. 1.

Fig. 3 is a schematic view showing the nozzle of the vehicle exhaust gas treating device of Fig. 1.

4 is a schematic view showing a carrier exhaust gas treatment device according to another embodiment of the present invention.

FIG. 5 is a flow chart showing a method for treating an exhaust gas of a vehicle according to an embodiment of the present invention.

Please refer to FIG. 1 , which illustrates a schematic diagram of a vehicle exhaust gas treatment device 100 in accordance with an embodiment of the present invention. Referring to FIGS. 2 and 3 together, a partial plan view of the vehicle exhaust gas treatment device 100 of FIG. 1 and a schematic view of the nozzle 130 are respectively shown. As shown, the vehicle exhaust gas treatment device 100 includes an exhaust gas passage 110, a mixing chamber 120, a nozzle 130, a reducing agent reservoir 140, a temperature sensor 150, and a cooling unit 160. The exhaust passage 110 includes a drain tube 111, and the drain tube 111 has a first end 111a and a second end 111b.

The first end 111a of the drainage tube 111 is connected to the exhaust gas passage 110, and the second end 111b of the drainage tube 111 is disposed on the side wall of the mixing chamber 120 to connect the one end portion 120a of the mixing chamber 120, and between the drainage tube 111 and the mixing chamber 120. It has an angle α. More specifically, the second end 111b of the draft tube 111 is tangent to the inner wall of the mixing chamber 120 (as shown in FIG. 2), and the angle α may be 110 degrees to 135 degrees.

On the other hand, the bottom of the mixing chamber 120 is in communication with the exhaust passage 110, and the temperature sensor 150 is used to sense the temperature within the exhaust passage 110. The cooling unit 160 is connected to the mixing chamber 120. The nozzle 130 is disposed at the end 120a of the mixing chamber 120 in a form orthogonal to the mixing chamber 120, and the reducing agent reservoir 140 is connected to the nozzle 130. More specifically, the position of the temperature sensor 150 is not limited, as long as the temperature in the exhaust gas passage 110 can be sensed and the opening and closing of the cooling unit 160 can be directly or indirectly controlled, for example, the indirect control is performed by Central controller. The cooling unit 160 may be an air pump, a water mister, a fan or a heat exchanger, etc., and the so-called cooling unit 160 is connected to the mixing chamber 120, for example, when the cooling unit 160 is an air pump or a water mister, It can be directly disposed on the mixing chamber 120 or indirectly connected to the mixing chamber 120 via the nozzle 130, as long as the cold air can be injected into the mixing chamber 120 to cool the mixing chamber 120. When the cooling unit 160 is a fan or a heat exchanger, it can be directly disposed on the cavity of the mixing chamber 120, as long as the heat energy of the mixing chamber 120 can be discharged to cool the mixing chamber 120. Further, the diameter D _a of the first end 111 a of the draft tube 111 is larger than the diameter D _{b of the} second end 111 _b , and the nozzle 130 has a surface water-resistant plating layer 131 (as shown in FIG. 3 ). More specifically, the ratio of the diameter D _a to the diameter D _b may be 1.5 to 3.

Since the drainage tube 111 is connected to the exhaust passage 110 and the mixing chamber 120 respectively, the exhaust gas in the exhaust passage 110 can be partially introduced into the mixing chamber 120 through the drainage tube 111, thereby effectively preheating the mist sprayed into the mixing chamber 120 through the nozzle 130. The reducing agent reduces the risk of poor conversion efficiency of the reducing agent due to failure to reach operating temperature. Secondly, since the second end 111b of the draft tube 111 is tangent to the inner wall of the mixing chamber 120, the exhaust gas can be introduced into the mixing chamber 120 through the draft tube 111 to form a vortex flow, thereby effectively driving the atomized reducing agent. Make it evenly distributed. Moreover, since the bottom of the mixing chamber 120 is in communication with the exhaust passage 110, the exhaust passage 110, the draft tube 111 and the mixing chamber 120 can form a passage, and the drainage tube connected between the exhaust passage 110 and the mixing chamber 120 The 111 is tapered from the exhaust passage 110 toward the mixing chamber 120, so that the flow field strength and the flow field velocity can be improved.

On the other hand, since the nozzle 130 has a surface water-resistant plating layer 131, and the draft tube 111 and the mixing chamber 120 have a configuration capable of forming a swirling airflow, the reducing agent droplet remaining around the nozzle hole or the nozzle hole of the nozzle 130 can be It is effectively carried away, thereby greatly reducing the crystal deposit formed by the instantaneous evaporation of the residual reducing agent due to high temperature. In addition, since the temperature in the exhaust passage 110 can be sensed by the temperature sensor 150, and the temperature sensor 150 can directly or indirectly control the opening and closing of the cooling unit 160, the carrier exhaust treatment device 100 can When the temperature of the exhaust gas is higher than the crystallization temperature of the reducing agent, timely introduction of cold air, water mist or heat exchange can not only effectively prevent the deposit of crystals of the reducing agent, but also reduce the temperature of the nozzle 130 and reduce the conventional air usage.

When the vehicle exhaust gas treatment device 100 is in operation, the flow conduit 111 has a flow rate Q ₁ therein, and in the passage formed by the exhaust passage 110, the draft tube 111 and the mixing chamber 120, the exhaust passage 110 has a flow rate Q ₂ therein. The ratios of the diameter D _a , the diameter D _b , the angle α , and the flow rate Q ₁ and the flow rate Q ₂ of the draft tube 111 according to each embodiment of the present invention are shown in Table 1 below.

Referring to FIG. 4, a schematic diagram of a vehicle exhaust gas treatment device 100 in accordance with another embodiment of the present invention is shown. As shown, the vehicle exhaust gas treatment device 100 includes an exhaust gas passage 110, a mixing chamber 120, a nozzle 130, a reducing agent reservoir 140, a temperature sensor 150, and a cooling unit 160. The exhaust passage 110 includes a drain tube 111, and the drain tube 111 has a first end 111a and a second end 111b. The carrier exhaust gas treatment device 100 is the same as the above-described embodiment except that the shape of the draft tube 111 and the relative position of the draft tube 111 are provided. More specifically, the draft tube 111 is disposed inside the exhaust passage 110 and the mixing chamber 120, and the drain tube 111 is The first end 111a is connected to the exhaust passage 110 and connected to the mixing chamber 120 at the second end 111b. Accordingly, the drainage tube 111 is not exposed, and the effects of external environmental factors can be mitigated.

Referring to FIG. 5, a flow chart of a method for treating an exhaust gas of a vehicle according to an embodiment of the present invention is shown. Please refer to Figure 1 together. As shown in the figure, first, in step 510, an exhaust gas in an exhaust gas passage is partially introduced into a mixing chamber by a drain pipe, wherein the exhaust gas passage and the draft pipe form a passage with the mixing chamber. Next, as in step 520, a reducing agent is injected into the mixing chamber. Then, as step 530, the temperature of the exhaust gas in the exhaust passage is sensed, and when the temperature of the exhaust gas in the exhaust passage is higher than the crystallization temperature of the reducing agent, a cooling unit is activated to cool the mixing chamber. Thereby, the reducing agent injected into the mixing chamber can be effectively preheated, and the mixing effect in the mixing chamber can be effectively improved. In addition to this, it is possible to prevent deposits of crystals of the reducing agent, reduce the nozzle temperature and reduce the conventional air usage.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention can be modified and modified without departing from the spirit and scope of the present invention. The scope is subject to the definition of the scope of the patent application attached.

100‧‧‧ Vehicle exhaust gas treatment device

110‧‧‧Exhaust passage

111‧‧‧Drainage tube

111a‧‧‧ first end

111b‧‧‧second end

120‧‧‧Mixed cavity

120a‧‧‧End

130‧‧‧Nozzles

140‧‧‧Reducing agent storage tank

150‧‧‧temperature sensor

160‧‧‧Cooling unit

D _a , D _b ‧‧‧ caliber

α ‧‧‧ angle

Claims (20)

A vehicle exhaust gas treatment device comprising: an exhaust gas passage comprising: a drainage tube having a first end and a second end; a mixing chamber communicating with the exhaust passage; and a nozzle disposed at one end of the mixing chamber And a reducing agent storage tank connected to the nozzle and atomizing a reducing agent into the mixing chamber through the nozzle; wherein the first end of the drainage tube is connected to the exhaust passage, and the second of the drainage tube The end is connected to the end of the mixing chamber, and the first end is tapered toward the second end, such that the diameter of the first end is larger than the diameter of the second end, and a part of the exhaust gas passes through the drainage tube to flow into the mixing The reducing agent is preheated in the chamber. The carrier exhaust gas treatment device of claim 1, wherein a ratio of a diameter of the first end to a diameter of the second end is 1.5 to 3. The carrier gas treatment device of claim 1, wherein the drainage tube has an angle with the mixing chamber. The carrier gas treatment device of claim 3, wherein the included angle is 110 degrees to 135 degrees. The carrier waste gas treatment device of claim 1, wherein the second end is disposed on a side wall of the mixing chamber to connect the end of the mixing chamber, and the second end is tangent to an inner wall of the mixing chamber. The carrier of claim 1, wherein the nozzle is orthogonal to the mixing chamber. The carrier of claim 1, wherein the nozzle has a surface water repellent coating. A vehicle exhaust gas treatment device comprising: an exhaust gas passage comprising: a drainage tube having a first end and a second end; a mixing chamber communicating with the exhaust passage; and a temperature sensor sensing the exhaust passage a temperature inside; a cooling unit connected to the mixing chamber; a nozzle disposed at one end of the mixing chamber; and a reducing agent reservoir connected to the nozzle and atomizing a reducing agent through the nozzle Into the mixing chamber; wherein the drainage tube is disposed inside the exhaust passage and the mixing chamber without being exposed, the first end of the drainage tube is connected to the exhaust passage, and the second end of the drainage tube is connected to the mixing chamber The end portion of the exhaust pipe is tapered from the exhaust passage to the mixing chamber, and a portion of the exhaust gas flows through the drain pipe into the mixing chamber to preheat the reducing agent, and the cooling unit is controlled by the Temperature sensor. The carrier exhaust gas treatment device of claim 8, wherein the diameter of the first end is greater than the diameter of the second end. The carrier exhaust gas treatment device of claim 9, wherein the ratio of the diameter of the first end to the diameter of the second end is 1.5 to 3. The carrier gas treatment device of claim 8, wherein the drainage tube has an angle with the mixing chamber. The carrier gas treatment device of claim 11, wherein the included angle is 110 degrees to 135 degrees. The carrier waste gas treatment device of claim 8, wherein the second end is disposed on a side wall of the mixing chamber to connect the end of the mixing chamber, and the second end is tangent to a top inner wall of the mixing chamber. The carrier of claim 8 wherein the nozzle is orthogonal to the mixing chamber. The carrier of claim 8 wherein the nozzle has a surface water repellent coating. A method for treating a vehicle exhaust gas, comprising: introducing an exhaust gas in an exhaust gas passage into a mixing chamber by a drain pipe, wherein the exhaust gas passage, the drain pipe and the mixing chamber form a passage, and the drain pipe is configured The exhaust passage to the mixing chamber is tapered to increase the flow field strength and the flow field speed of the exhaust gas; inject a reducing agent into the mixing chamber, and preheat the reducing agent by using the temperature of the exhaust gas; The temperature of the exhaust gas in the exhaust passage is sensed, and when the temperature of the exhaust gas in the exhaust passage is higher than the crystallization temperature of the reducing agent, a cooling unit is activated to cool the mixing chamber. The method of claim 16, wherein the drainage tube has a first end and a second end, the first end of the drainage tube is connected to the exhaust passage, and the second end of the drainage tube is connected to the mixing a cavity, and the diameter of the first end is larger than the diameter of the second end. The method of treating an exhaust gas of claim 17, wherein the ratio of the diameter of the first end to the diameter of the second end is 1.5 to 3. The method of claim 16, wherein the draft tube has an angle with the mixing chamber, and the angle is between 110 degrees and 135 degrees. The method of claim 16, wherein the reducing agent is injected into the mixing chamber with a nozzle, and the nozzle has a surface water repellent coating.