Pollutant emission control system of explosion-proof diesel engine

Abstract

The invention relates to the technical field of diesel engine tail gas treatment, and discloses an explosion-proof diesel engine pollutant emission control system which comprises a real-time monitoring module, a monitoring sensor, an intelligent control module, a multi-stage catalytic filtering module and an exhaust gas recirculation module. According to the multi-stage catalytic filtering module, a particulate matter collecting and regenerating module, a diesel oxidation catalyst and a diesel particulate filter are arranged in a tail gas treatment box to treat waste gas exhausted by the diesel engine. The real-time monitoring module is used for monitoring the internal temperature and the inlet and outlet pressure of the diesel particulate filter by arranging a differential pressure sensor and a temperature sensor in the tail gas treatment box. The particulate matter collecting and regenerating module and the diesel oil oxidation catalyst are alternately used, and the passive regeneration technology of the particulate filter is added, so that the regeneration temperature is reduced to 300 DEG C or below, the explosion risk caused by the high temperature (larger than 550 DEG C) required by active regeneration of a traditional particulate filter is thoroughly avoided, and the diesel oil regeneration system is particularly suitable for inflammable and explosive environments such as mines.

Description

Technical Field

[0001] The present invention relates to the technical field of diesel engine exhaust gas treatment, and particularly to an explosion-proof diesel engine pollutant emission control system. Background Art

[0002] The auxiliary transportation methods in coal mines are new energy power and diesel power. It is an area where explosion-proof trackless rubber-tyred vehicles are intensively used. The occupancy rate of explosion-proof vehicles powered by diesel engines is 90%. Some explosion-proof diesel engine trackless rubber-tyred vehicles are equipped with DOC to solve CO. According to market research, basically all use the catalytic method with rare earth coatings. The purification life of CO is short. After the explosion-proof vehicles using DPF for particulate matter collection are blocked, they can only be regenerated offline. The proportion of new energy explosion-proof vehicles is 10%. Due to the generally immature technology of the battery's endurance ability, the application rate of new energy explosion-proof vehicles is low, and there is still a long way to go to improve their use. Therefore, the auxiliary transportation trackless rubber-tyred vehicles in coal mines still rely on fuel power. However, after the explosion-proof transformation of diesel engines meeting the national IV emission standards for fuel power, various data will change.

[0003] A prior patent discloses a control system and control method for reducing NOx emissions from diesel engines under all operating conditions (publication number CN105545501A). It includes an engine, an air filter, a compressor, a turbine coaxially connected to the compressor, an intake air intercooler, an intake manifold, an exhaust manifold, a lambda sensor and an intake pipe pressure sensor provided on the exhaust manifold, a coolant temperature sensor provided on the engine, a high-response torque sensor and a high-response speed sensor, an exhaust pipe pressure sensor provided on the exhaust pipe, a single-chip microcomputer with an air-fuel ratio calculation program, an electronic control unit ECU, a butterfly valve, two EGR valves and an EGR cooler. The following defects exist in the technology disclosed in this patent: When DPF active regeneration requires high temperature (>550°C), it is easy to cause an explosion in a flammable and explosive environment; and in the technology disclosed in this patent, due to the poor coordination between the exhaust gas recirculation and the after-treatment components, the purification efficiency is low and the occupied space is large. Summary of the Invention

[0004] The main technical problem to be solved by the present invention is to provide an explosion-proof diesel engine pollutant emission control system, which solves the problems in the above background art.

[0005] To solve the above technical problem, according to one aspect of the present invention, more specifically, an explosion-proof diesel engine pollutant emission control system includes a real-time monitoring module, a monitoring sensor, an intelligent control module, a multi-stage catalytic filtration module, and an exhaust gas recirculation module; The multi-stage catalytic filtration module processes the exhaust gas discharged from the diesel engine by setting a particulate matter collection and regeneration module, a diesel oxidation catalyst, and a diesel particulate filter inside the exhaust gas treatment box; The real-time monitoring module monitors the internal temperature and the inlet and outlet pressures of the diesel particulate filter by arranging a differential pressure sensor and a temperature sensor inside the tail gas treatment tank; The monitoring sensor is used to monitor the nitrogen oxide content, particulate matter concentration, and oxygen content in the tail gas after being treated by the tail gas treatment tank; The exhaust gas recirculation module is used to increase or decrease the reflux amount of the exhaust gas; The intelligent control module switches between the particulate matter collection and regeneration module and the diesel oxidation catalytic converter according to the feedback of the real-time monitoring module, and adjusts the reflux amount of the exhaust gas in the exhaust gas recirculation module according to the feedback of the monitoring sensor.

[0006] Furthermore, the monitoring sensor specifically includes a nitrogen oxide sensor, a particulate matter sensor, and an oxygen sensor.

[0007] Furthermore, the intelligent control module determines the control of the exhaust gas recirculation module according to the nitrogen oxide content, particulate matter concentration, and oxygen content in the tail gas after being treated by the tail gas treatment tank, as follows: ; In the formula, represents the adjustment condition coefficient of the exhaust gas recirculation module, represents the nitrogen oxide content in the tail gas after being treated by the tail gas treatment tank, represents the particulate matter concentration in the exhaust gas, represents the oxygen content in the exhaust gas.

[0008] Furthermore, when it means that it is necessary to increase the reflux amount of the exhaust gas in the exhaust gas recirculation module; When it means to maintain the current reflux amount of the exhaust gas in the exhaust gas recirculation module; When it means that it is necessary to reduce the reflux amount of the exhaust gas in the exhaust gas recirculation module.

[0009] Furthermore, the intelligent control module detects the internal temperature of the tail gas treatment tank through the temperature sensor and detects the inlet and outlet pressures of the diesel particulate filter according to the differential pressure sensor, where: ; In the formula, represents the pressure difference between the inlet and outlet of the diesel particulate filter, represents the air pressure magnitude at the inlet of the diesel particulate filter, represents the air pressure magnitude at the outlet of the diesel particulate filter.

[0010] Furthermore, when When the temperature monitored by the temperature sensor is < 300 °C, trigger the particulate collection and regeneration module to oxidize particulate matter using the exhaust waste heat; When and the temperature monitored by the temperature sensor is > 300 °C, switch to the diesel oxidation catalyst for auxiliary catalytic regeneration.

[0011] Furthermore, the pollutant emission control system of the explosion-proof diesel engine further includes an alarm display terminal, which integrates audible and visual alarm and wireless transmission functions, automatically cuts off the fuel and starts emergency cooling when the standard is exceeded.

[0012] Furthermore, the particulate collection and regeneration module and the diesel oxidation catalyst alternately catalyze and convert the exhaust gas entering the tail gas treatment box, and the catalyzed and converted gas then enters the diesel particulate filter for filtration treatment.

[0013] Furthermore, the tail gas treatment box is coated with a titanium-aluminum composite coating that can withstand corrosive gases .

[0014] An explosion-proof diesel engine pollutant emission control system provided by the present invention, compared with the prior art, the effects obtained by this method are: 1. By alternately using the particulate collection and regeneration module and the diesel oxidation catalyst, and adding the passive regeneration technology of the particulate filter, the present invention reduces the regeneration temperature below 300 °C, completely avoiding the explosion risk caused by the high temperature (> 550 °C) required for the active regeneration of the traditional particulate filter, and is especially suitable for flammable and explosive environments such as mines.

[0015] 2. By proposing a dynamic cooperative control algorithm for exhaust gas recirculation and diesel oxidation catalyst, and optimizing the exhaust gas return flow in real time through the mathematical model of the adjustment coefficient G (combining nitrogen oxides, particulate matter concentration, and oxygen content), the present invention realizes a 40% improvement in the reduction efficiency of nitrogen oxides and particulate matter.

[0016] 3. By using the differential pressure sensor and the temperature sensor to monitor the state of the tail gas treatment box in real time, and intelligently switching the working modes of the particulate collection and regeneration module and the diesel oxidation catalyst, the present invention ensures efficient catalysis and safe regeneration.

[0017] 4. By integrating audible and visual alarm, wireless transmission and emergency control functions, automatically cutting off the fuel and starting cooling when the standard is exceeded, the present invention meets the requirements of mine intelligence and unmanned operation. Brief Description of the Drawings

[0018] Figure 1 is the flowchart of the present invention; Figure 2 is the three-dimensional surface diagram of the G value changing with and in the present invention; Figure 3 For the G value in the present invention Trend chart of variation Figure 4 For the G value in the present invention varying with Trend chart of variation Figure 5 For the G value in the present invention varying with Trend chart of variation Specific embodiments

[0019] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Embodiment 1 As Figure 1 shown, according to one aspect of the present invention, an explosion-proof diesel engine pollutant emission control system is provided, including a real-time monitoring module, a monitoring sensor, an intelligent control module, a multi-stage catalytic filtration module, and an exhaust gas recirculation module; the multi-stage catalytic filtration module processes the exhaust gas discharged from the diesel engine by arranging a particulate matter collection and regeneration module, a diesel oxidation catalyst, and a diesel particulate filter inside the exhaust gas treatment tank; the real-time monitoring module monitors the internal temperature and the inlet and outlet pressures of the diesel particulate filter by arranging a differential pressure sensor and a temperature sensor inside the exhaust gas treatment tank; the monitoring sensor is used to monitor the nitrogen oxide content, particulate matter concentration, and oxygen content in the exhaust gas after being treated by the exhaust gas treatment tank; the exhaust gas recirculation module is used to increase or decrease the return flow of the exhaust gas; the intelligent control module switches between the particulate matter collection and regeneration module and the diesel oxidation catalyst according to the feedback of the real-time monitoring module, and adjusts the exhaust gas return flow in the exhaust gas recirculation module according to the feedback of the monitoring sensor. By alternately using the particulate matter collection and regeneration module and the diesel oxidation catalyst, and adding the passive regeneration technology of the particulate filter, the regeneration temperature is reduced to below 300°C, completely avoiding the explosion risk caused by the high temperature (>550°C) required for the active regeneration of the traditional particulate filter, and is particularly suitable for flammable and explosive environments such as mines.

[0021] Embodiment 2

[0022] As Figures 1-5 shown, the monitoring sensor specifically includes a nitrogen oxide sensor, a particulate matter sensor, and an oxygen sensor. The intelligent control module determines the control of the exhaust gas recirculation module according to the nitrogen oxide content, particulate matter concentration, and oxygen content in the exhaust gas after being treated by the exhaust gas treatment tank, including: ; In the formula, represents the adjustment condition coefficient of the exhaust gas recirculation module (as Figure 2 shown, G varies with and The mathematical model of the change, where m = 0.3 g / kWh). Represents the nitrogen oxide content in the tail gas after being treated by the tail gas treatment box (as Figure 3 shown, G varies with the mathematical model of the change, where = 9%, m = 0.3). Represents the particulate matter concentration in the tail gas (as Figure 4 shown, the value of G varies with the mathematical model of the change, where = 3.2, m = 0.3). Represents the oxygen content in the tail gas (as Figure 5 shown, the mathematical model of G varying with m, where = 3.2, = 9%).

[0023] Among them, the adjustment condition coefficient of any exhaust gas recirculation module is calculated. The nitrogen oxide content in the tail gas after being treated by the tail gas treatment box takes (g / kWh), the particulate matter concentration in the tail gas after being treated by the tail gas treatment box takes (g / kWh), the oxygen content in the tail gas after being treated by the gas treatment box takes . Then there is: ; It can be known from the above calculation that the adjustment condition coefficient of this exhaust gas recirculation module is , then it means that at this time, it is necessary to reduce the exhaust gas return flow of the exhaust gas recirculation module to reduce the combustion temperature, and the reduction amount each time does not exceed 15%. And by comparing multiple groups of data, there is: Table 1 The relationship between the parameters of some embodiments and the adjustment of the exhaust gas recirculation module

[0024] It can be known from the data in Table 1 above that when the sample tends to infinity, there will be a limit for judging the state of the recirculation module with the adjustment condition coefficient , that is, when , it means that it is necessary to increase the exhaust gas return flow of the exhaust gas recirculation module to increase the combustion temperature, and the increase amount each time does not exceed 15%; when , it means to maintain the current exhaust gas return flow of the exhaust gas recirculation module. When , it means that it is necessary to reduce the exhaust gas return flow of the exhaust gas recirculation module to reduce the combustion temperature, and the reduction amount each time does not exceed 15%.

[0025] Example 3

[0026] As Figure 1As shown in the figure, the intelligent control module detects the internal temperature of the tail gas treatment box through a temperature sensor, and detects the inlet and outlet pressures of the diesel particulate filter according to a differential pressure sensor, where there are: ; In the formula, represents the pressure difference between the inlet and outlet of the diesel particulate filter, represents the air pressure at the inlet of the diesel particulate filter, represents the air pressure at the outlet of the diesel particulate filter. When and the temperature monitored by the temperature sensor is <300 °C, the particulate matter collection and regeneration module is triggered to oxidize particulate matter using the exhaust heat; when and the temperature monitored by the temperature sensor is >300 °C, it switches to the diesel oxidation catalyst for auxiliary catalytic regeneration. This technology of "POC low-temperature on-line regeneration + DPF passive regeneration" reduces the regeneration temperature to below 300 °C, completely avoiding the explosion risk caused by the high temperature (>550 °C) required for traditional DPF active regeneration, and is especially suitable for flammable and explosive environments such as mines.

[0027] Embodiment 4

[0028] As Figure 1 shown, the pollutant emission control system of the explosion-proof diesel engine further includes an alarm display terminal, which integrates the functions of sound and light alarm and wireless transmission, and automatically cuts off the fuel and starts emergency cooling when the standard is exceeded. The particulate matter collection and regeneration module and the diesel oxidation catalyst alternately catalyze and convert the tail gas entering the tail gas treatment box, and the catalyzed and converted gas then enters the diesel particulate filter for filtration treatment. The tail gas treatment box is coated with a titanium-aluminum composite coating that can withstand corrosive gases . The tail gas treatment box is coated with a titanium-aluminum composite coating, which can withstand and other corrosive gases, and can effectively extend the life of the system.

[0029] The above embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. An explosion-proof diesel engine pollutant emission control system, characterized in that: It includes real-time monitoring module, monitoring sensor, intelligent control module, multi-stage catalytic filtration module and exhaust gas recirculation module; The multi-stage catalytic filtering module processes the exhaust gas discharged from the diesel engine by arranging a particle collection and regeneration module, a diesel oxidation catalyst and a diesel particulate filter inside the exhaust treatment box; The real-time monitoring module monitors the internal temperature and the inlet and outlet pressures of the diesel particulate filter by arranging a differential pressure sensor and a temperature sensor inside the exhaust gas treatment box; The monitoring sensor is used to monitor the nitrogen oxide content, particulate matter concentration, and oxygen content in the exhaust gas after being treated by the exhaust treatment box; The exhaust gas recirculation module is used to increase or decrease the recirculation amount of the exhaust gas; The intelligent control module switches between the particulate matter collection and regeneration module and the diesel oxidation catalyst according to the feedback from the real-time monitoring module, and adjusts the exhaust gas recirculation volume in the exhaust gas recirculation module according to the feedback from the monitoring sensor.

2. The explosion-proof diesel engine pollutant emission control system according to claim 1, characterized in that: The monitoring sensors specifically include a nitrogen oxide sensor, a particulate matter sensor, and an oxygen sensor.

3. The explosion-proof diesel engine pollutant emission control system according to claim 1, characterized in that: The intelligent control module determines the control of the exhaust gas recirculation module according to the nitrogen oxide content, particulate matter concentration and oxygen content in the exhaust gas after being treated by the exhaust treatment box: ； In the formula, represents the regulation condition coefficient of the exhaust gas recirculation module, Indicates the nitrogen oxide content in the exhaust gas after being treated by the exhaust treatment box. Indicates the concentration of particulate matter in the exhaust gas. Indicates the oxygen content in the exhaust gas.

4. The explosion-proof diesel engine pollutant emission control system according to claim 3, characterized in that: when When , it means that the exhaust gas recirculation volume of the exhaust gas recirculation module needs to be increased; when When , it means maintaining the exhaust gas recirculation volume of the current exhaust gas recirculation module; when When , it means that the exhaust gas recirculation volume of the exhaust gas recirculation module needs to be reduced.

5. The explosion-proof diesel engine pollutant emission control system according to claim 1, characterized in that: The intelligent control module detects the internal temperature of the exhaust gas treatment box through a temperature sensor, and detects the inlet and outlet pressures of the diesel particulate filter according to a pressure difference sensor, including: ； In the formula, Indicates the pressure difference between the inlet and outlet of the diesel particulate filter. Indicates the air pressure at the inlet of the diesel particulate filter. Indicates the air pressure at the diesel particulate filter outlet.

6. The explosion-proof diesel engine pollutant emission control system according to claim 5, characterized in that: when When the temperature monitored by the temperature sensor is less than 300°C, the particle collection and regeneration module is triggered to oxidize the particles using exhaust waste heat; when When the temperature monitored by the temperature sensor is >300°C, the system switches to diesel oxidation catalyst assisted catalytic regeneration.

7. The explosion-proof diesel engine pollutant emission control system according to claim 1, characterized in that: The explosion-proof diesel engine pollutant emission control system also includes an alarm display terminal, which integrates sound and light alarm and wireless transmission functions, and automatically cuts off fuel and starts emergency cooling when exceeding the standard.

8. The explosion-proof diesel engine pollutant emission control system according to claim 1, characterized in that: The particulate matter collection and regeneration module and the diesel oxidation catalyst alternately catalytically convert the exhaust gas entering the exhaust gas treatment box, and the catalytically converted gas then enters the diesel particulate filter for filtering treatment.

9. The explosion-proof diesel engine pollutant emission control system according to claim 1, characterized in that: The tail gas treatment box adopts a method of withstanding corrosive gases. Titanium-aluminum composite coating.

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