CN105822391A - Nitrogen dioxide treatment method and system in automobile exhaust - Google Patents

Abstract

The invention relates to a method and a system for treating nitrogen dioxide in automobile exhaust, wherein the method comprises the following steps: the method comprises the following steps of monitoring the automobile exhaust in real time in an infrared detection mode, and generating a corresponding electric signal according to the wavelength range of absorbed infrared rays and the degree of absorption; analyzing the generated electric signals to obtain the types and the contents of harmful gases; identifying each harmful gas according to the type of the harmful gas; judging whether the tail gas is the tail gas which is discharged in an overrun way or not according to the content of each harmful gas; if yes, judging whether the harmful gas which is over-limit discharged in the tail gas contains nitrogen dioxide or not according to the identification; and if the harmful gas which is over-limit discharged in each tail gas contains nitrogen dioxide according to the identification, generating a catalytic reaction instruction, and discharging the tail gas into a photocatalytic reactor for nitrogen dioxide treatment through the catalytic reaction instruction. The invention can effectively and timely treat the automobile exhaust which is over-limit discharged, and reduces the environmental pollution and the personal injury.

Description

Nitrogen dioxide treatment method and system in automobile exhaust

technical field

The invention relates to the technical field of automobiles, in particular to a method for treating nitrogen dioxide in automobile exhaust and a system for treating nitrogen dioxide in automobile exhaust.

Background technique

The emission of automobile exhaust is a matter of great concern to the society. The exhaust emitted by automobiles contains various harmful gases including carbon monoxide (CO), nitrogen monoxide (NO) and nitrogen dioxide (NO ₂ ), which on the one hand cause In addition to environmental pollution, on the other hand, it will also cause harm to people.

For example, nitrogen dioxide in vehicle exhaust is a corrosive gas. In the early stage of inhaling nitrogen dioxide gas, there will be mild eye and upper respiratory tract irritation symptoms, such as throat discomfort, dry cough, etc., and after a few hours of incubation, chest tightness, respiratory distress, cough, foamy sputum, cyanosis, etc. will occur. Or it may even cause fainting.

Therefore, how to further treat the nitrogen dioxide in the exhaust gas of vehicles with excessive emissions, so as to reduce the environmental pollution and personal injury caused by the nitrogen dioxide in the exhaust gas, has become an urgent problem to be solved.

Contents of the invention

In view of the deficiencies in the prior art, the object of the present invention is to provide a method and system for treating nitrogen dioxide in automobile exhaust, which can effectively process the nitrogen dioxide in automobile exhaust with over-limit emissions in time, and reduce the impact of automobile exhaust. Environmental pollution and personal injury.

To achieve the above object, the present invention adopts the following technical solutions:

A method for treating nitrogen dioxide in automobile exhaust gas, comprising the steps of:

Car exhaust is monitored in real time by means of infrared detection, and corresponding electrical signals are generated according to the wavelength range and degree of absorption of infrared rays absorbed;

According to the generated electrical signal analysis, the type and content of harmful gases can be obtained;

Label each harmful gas according to the type of harmful gas;

According to the content of each harmful gas, it is judged whether the exhaust gas is exhaust gas exceeding the limit;

If so, judge whether the harmful gas discharged beyond the limit in the tail gas contains nitrogen dioxide according to the mark;

If it is judged according to the identification that the harmful gas discharged beyond the limit in each tail gas contains nitrogen dioxide, a catalytic reaction command is generated, and the tail gas is discharged into the photocatalytic reactor for nitrogen dioxide treatment through the catalytic reaction command.

The present invention also provides a nitrogen dioxide treatment system in automobile exhaust, comprising:

Exhaust gas detection module, used for real-time monitoring of vehicle exhaust by means of infrared detection, and generating corresponding electrical signals according to the wavelength range and degree of absorption of infrared rays absorbed;

The signal analysis module is used to obtain the type and content of harmful gases according to the generated electrical signal analysis;

The identification module is used to identify each harmful gas according to the type of harmful gas;

The first judging module is used to judge whether the tail gas is the tail gas discharged beyond the limit according to the content of various harmful gases;

The second judging module is used to judge whether the harmful gas discharged beyond the limit in the tail gas contains nitrogen dioxide according to the mark when the judgment result of the first judging module is yes;

The nitrogen dioxide processing module is configured to generate a catalytic reaction instruction when the judgment result of the second judging module is yes, and discharge the exhaust gas into the photocatalytic reactor for nitrogen dioxide treatment through the catalytic reaction instruction.

Compared with the prior art, a method and system for treating nitrogen dioxide in automobile exhaust gas of the present invention detects the types and contents of harmful gases contained in automobile exhaust gas by means of infrared detection, and detects various harmful gases. The gas is marked, and the harmful gas discharged beyond the standard is treated separately according to the mark and content, focusing on the treatment of nitrogen dioxide to achieve targeted treatment of harmful gases, which can effectively improve the efficiency of tail gas treatment and avoid the impact of automobile tail gas on the environment. pollution and personal injury.

Description of drawings

Fig. 1 is the schematic flow sheet of the nitrogen dioxide treatment method in a kind of automobile tail gas in the embodiment of the present invention;

Fig. 2 is a schematic diagram of a system for treating nitrogen dioxide in automobile exhaust in an embodiment of the present invention.

detailed description

Below, in conjunction with accompanying drawing and specific embodiment, the present invention is described further:

After the automobile exhaust gas passes through the purifier, the harmful gas contained in it will usually be in a standard state, but in the case of engine failure or purifier failure, excessive exhaust gas may appear. The present invention is mainly aimed at the secondary treatment of exhaust gas . As shown in Figure 1, a kind of nitrogen dioxide processing method in the automobile tail gas described in the present embodiment comprises the following steps:

Step S101 , real-time monitoring of vehicle exhaust by means of infrared detection, and generating corresponding electrical signals according to the wavelength range and degree of absorption of infrared rays absorbed.

Step S102, analyzing and obtaining the type and content of the harmful gas according to the generated electrical signal.

Because automobile exhaust usually contains various harmful gases such as nitric oxide, hydrocarbons, sulfur oxides, and nitrogen oxides. Each of these gases has a specific characteristic absorption band and characteristic frequency, and when the infrared spectrum falls near the characteristic frequency band, it will be strongly absorbed. Therefore, the composition of harmful gases in the exhaust gas can be detected through the infrared spectrum of the corresponding characteristic frequency, and the amount of the absorbed outer spectrum can detect the content of the corresponding gas.

Step S103, mark each harmful gas according to the type of harmful gas. It is convenient to distinguish different harmful gases through identification.

Step S104, according to the contents of various harmful gases, it is judged whether the tail gas is the tail gas discharged beyond the limit. If yes, it means that there is at least one harmful gas in the exhaust gas that exceeds the national standard. At this time, step S105 is executed to realize the processing of the exhaust gas discharged beyond the limit according to the label. Otherwise, it means that there is no harmful gas in the exhaust gas of the vehicle or even so little that it can be ignored. At this time, return to step S101 to continue monitoring.

Step S105, if yes, judge whether the harmful gas discharged beyond the limit in the tail gas contains nitrogen dioxide according to the identification. If the exhaust gas contains nitrogen dioxide, step S106 may be performed.

Step S106, if the judgment result of step S105 is yes, that is, if it is judged according to the label that the harmful gas discharged beyond the limit in each tail gas contains nitrogen dioxide, a catalytic reaction command is generated, and the tail gas is discharged to Nitrogen dioxide treatment in a photocatalytic reactor.

Specifically, in this embodiment, the nitrogen dioxide can be absorbed and treated by passing the exhaust gas through a photocatalytic reaction layer of titanium dioxide and emitting ultraviolet rays by an ultraviolet lamp. Since this embodiment is for the secondary treatment of automobile exhaust, usually automobile The content of harmful substances in the exhaust gas is usually not too high, so the nitrogen dioxide can be completely absorbed and treated after the photocatalytic reaction.

In one embodiment, if in step S105, it is judged according to the identification that the harmful gas discharged beyond the limit in each tail gas contains carbon monoxide in addition to nitrogen dioxide, an absorption instruction can be generated, and after the nitrogen dioxide is processed , through this absorption command, the tail gas is discharged into a container with a carbon monoxide absorbent for carbon monoxide treatment.

As a preferred embodiment, the carbon monoxide absorbent can be a composition composed of a porous inorganic carrier and a binary complex of nitride and copper chloride carried on it, and nitrogen in the composition Compounds can account for 0.5-0.8 molar ratio. In addition, the inorganic carrier can be: porous ceramics, activated carbon or titanium oxide, etc. The nitride can be: pyridine and composition etc. The carbon monoxide absorbent can effectively absorb the monoxide in the tail gas.

In addition, as a better embodiment, the process of discharging tail gas into the photocatalytic reactor for nitrogen dioxide treatment includes:

Determine the concentration of nitrogen dioxide in the tail gas according to the content of the harmful gas;

Obtain the speed of the automobile engine and the current temperature in the photocatalytic reactor in real time; specifically, the current temperature can be obtained by placing a temperature sensor in the photocatalytic reactor;

A reference speed is calculated according to the rotation speed, current temperature and concentration, and the speed at which the tail gas is discharged into the photocatalytic reactor is adjusted according to the reference speed.

In this embodiment, the following formula can be used to calculate the reference speed:

$\mathrm{<span\; class="notranslate">\; V</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; *</span>\frac{\mathrm{<span\; class="notranslate">\; C</span>}}{\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; ;</span>$

In the above formula, V is the reference speed; r is the speed of the automobile engine, C is the concentration of nitrogen dioxide, T is the current temperature in the photocatalytic reactor, and a is a constant coefficient between 0.15-0.37. By controlling the speed at which the tail gas is discharged into the photocatalytic reactor, nitrogen dioxide can be more completely absorbed in the photocatalytic reactor, thereby effectively improving the efficiency of nitrogen dioxide treatment. In particular, a large number of experimental data have proved that when the value of a is 0.2, the efficiency of nitrogen dioxide treatment will reach the best.

Referring to Fig. 2, corresponding to the nitrogen dioxide treatment method in the above-mentioned automobile exhaust, the present invention also provides a nitrogen dioxide treatment system in the automobile exhaust, comprising:

Exhaust gas detection module 101, used for real-time monitoring of vehicle exhaust by means of infrared detection, and generating corresponding electrical signals according to the wavelength range and degree of absorption of infrared rays absorbed;

The signal analysis module 102 is used to obtain the type and content of the harmful gas according to the generated electrical signal analysis;

An identification module 103, configured to identify each harmful gas according to the type of harmful gas;

The first judging module 104 is used to judge whether the tail gas is the tail gas discharged beyond the limit according to the content of various harmful gases;

The second judging module 105 is used to judge whether the harmful gas discharged beyond the limit in the tail gas contains nitrogen dioxide according to the mark when the judgment result of the first judging module is yes;

The nitrogen dioxide processing module 106 is configured to generate a catalytic reaction instruction when the judgment result of the second judgment module is yes, and discharge the exhaust gas into the photocatalytic reactor for nitrogen dioxide treatment through the catalytic reaction instruction.

As a preferred embodiment, the nitrogen dioxide treatment system in a kind of automobile tail gas of the present invention can also comprise:

The carbon monoxide processing module is used to generate an absorption instruction if it is judged according to the label that the harmful gas discharged beyond the limit in each tail gas also contains carbon monoxide, and after the nitrogen dioxide is processed, the tail gas is discharged to a level with carbon monoxide through the absorption instruction. Carbon monoxide treatment is carried out in the absorbent container.

Preferably, the nitrogen dioxide treatment module may include:

A concentration calculation module, used to determine the concentration of nitrogen dioxide in the tail gas according to the content of the harmful gas;

A parameter acquisition module, used to acquire the speed of the automobile engine and the current temperature in the photocatalytic reactor in real time;

The speed adjustment module is used to calculate a reference speed according to the rotation speed, current temperature and concentration, and adjust the speed of exhaust gas discharged into the photocatalytic reactor according to the reference speed. By controlling the speed at which the tail gas is discharged into the photocatalytic reactor, nitrogen dioxide can be more completely absorbed in the photocatalytic reactor, which can effectively improve the efficiency of nitrogen dioxide treatment

Other technical features of the system for treating nitrogen dioxide in automobile exhaust are the same as those of the method for treating nitrogen dioxide in automobile exhaust of the present invention, and will not be repeated here.

To sum up, the nitrogen dioxide treatment method and system in the automobile exhaust of the present invention mainly carry out secondary treatment on the automobile exhaust, and detect the types and contents of harmful gases contained in the automobile exhaust by means of infrared detection, and Label all kinds of harmful gases, and treat the harmful gases that exceed the standard according to the labels and contents, and focus on the treatment of nitrogen dioxide to achieve targeted treatment of harmful gases, which can effectively improve the efficiency of exhaust gas treatment and avoid automobile pollution. Exhaust gas pollutes the environment and injures people.

Those skilled in the art can make various other corresponding changes and deformations according to the above-described technical solutions and concepts, and all these changes and deformations should fall within the protection scope of the claims of the present invention.

Claims (8)

1. a nitrogen dioxide treatment method in automobile exhaust, is characterized in that, comprises the steps: Car exhaust is monitored in real time by means of infrared detection, and corresponding electrical signals are generated according to the wavelength range and degree of absorption of infrared rays absorbed; According to the generated electrical signal analysis, the type and content of harmful gases can be obtained; Label each harmful gas according to the type of harmful gas; According to the content of each harmful gas, it is judged whether the exhaust gas is exhaust gas exceeding the limit; If so, judge whether the harmful gas discharged beyond the limit in the tail gas contains nitrogen dioxide according to the mark; If it is judged according to the identification that the harmful gas discharged beyond the limit in each tail gas contains nitrogen dioxide, a catalytic reaction command is generated, and the tail gas is discharged into the photocatalytic reactor for nitrogen dioxide treatment through the catalytic reaction command. 2. the nitrogen dioxide treatment method in the automobile tail gas according to claim 1, is characterized in that, the described process of carrying out nitrogen dioxide treatment comprises: Nitrogen dioxide is absorbed and treated by passing the exhaust gas through a photocatalytic reaction layer of titanium dioxide and emitting ultraviolet rays by ultraviolet lamps. 3. The method for treating nitrogen dioxide in automobile exhaust according to claim 1, characterized in that, if it is judged according to the mark that the harmful gas discharged beyond the limit in each exhaust gas also contains carbon monoxide, then an absorption instruction is generated and processed After the nitrogen dioxide is exhausted, the exhaust gas is discharged into a container with a carbon monoxide absorbent for carbon monoxide treatment through the absorption instruction. 4. the nitrogen dioxide treatment method in the automobile tail gas according to claim 3, is characterized in that, described carbon monoxide absorbent is the binary coordination of nitride and cupric chloride carried on it by porous inorganic carrier Compositions composed of substances, and the nitrides in the composition account for 0.5-0.8 molar ratio; the inorganic carrier includes: porous ceramics, activated carbon or titanium oxide; the nitrides are pyridine and Compositions. 5. according to the nitrogen dioxide processing method in the automobile tail gas described in any one of claim 1-4, it is characterized in that, described tail gas is discharged into the photocatalytic reactor and carries out the process of nitrogen dioxide treatment comprising: Determine the concentration of nitrogen dioxide in the tail gas according to the content of the harmful gas; Obtaining the rotational speed of the automobile engine and the current temperature in the photocatalytic reactor in real time; A reference speed is calculated according to the rotation speed, current temperature and concentration, and the speed at which the tail gas is discharged into the photocatalytic reactor is adjusted according to the reference speed. 6. A nitrogen dioxide treatment system in automobile exhaust, characterized in that, comprising: Exhaust gas detection module, used for real-time monitoring of vehicle exhaust by means of infrared detection, and generating corresponding electrical signals according to the wavelength range and degree of absorption of infrared rays absorbed; The signal analysis module is used to obtain the type and content of harmful gases according to the generated electrical signal analysis; The identification module is used to identify each harmful gas according to the type of harmful gas; The first judging module is used to judge whether the tail gas is the tail gas discharged beyond the limit according to the content of various harmful gases; The second judging module is used to judge whether the harmful gas discharged beyond the limit in the tail gas contains nitrogen dioxide according to the mark when the judgment result of the first judging module is yes; The nitrogen dioxide processing module is configured to generate a catalytic reaction instruction when the judgment result of the second judging module is yes, and discharge the exhaust gas into the photocatalytic reactor for nitrogen dioxide treatment through the catalytic reaction instruction. 7. The nitrogen dioxide treatment system in automobile exhaust according to claim 6, further comprising: The carbon monoxide processing module is used to generate an absorption instruction if it is judged according to the label that the harmful gas discharged beyond the limit in each tail gas also contains carbon monoxide, and after the nitrogen dioxide is processed, the tail gas is discharged to a level with carbon monoxide through the absorption instruction. Carbon monoxide treatment is carried out in the absorbent container. 8. The nitrogen dioxide treatment system in the automobile exhaust according to claim 6 or 7, wherein the nitrogen dioxide treatment module comprises: A concentration calculation module, used to determine the concentration of nitrogen dioxide in the tail gas according to the content of the harmful gas; A parameter acquisition module, used to acquire the speed of the automobile engine and the current temperature in the photocatalytic reactor in real time; The speed adjustment module is used to calculate a reference speed according to the rotation speed, current temperature and concentration, and adjust the speed of exhaust gas discharged into the photocatalytic reactor according to the reference speed.