An explosion-proof temperature control system and method for an explosion-proof diesel engine exhaust aftertreatment device

Abstract

The application discloses an explosion-proof temperature control system and method for a tail gas aftertreatment device of an explosion-proof diesel engine, wherein two ends of a water cooling jacket of the aftertreatment device are connected with an explosion-proof electromagnetic valve and an explosion-proof water pump respectively, the explosion-proof electromagnetic valve is connected with a thermostat in two ways, one way is directly connected with the thermostat, and the other way is connected with the thermostat through a urea tank heating pipe, the thermostat is connected with an explosion-proof radiator and the explosion-proof water pump respectively, the explosion-proof radiator is connected with the explosion-proof water pump, and a cooling water temperature sensor is arranged at the rear part of the water cooling jacket of the aftertreatment device. The circulating cooling water covers the surface of the tail gas aftertreatment device, controls the surface temperature of the tail gas aftertreatment device during operation, and utilizes the explosion-proof radiator to timely radiate the cooling water, so that the explosion-proof modification of the tail gas aftertreatment device is completed, and the underground application of the tail gas aftertreatment device is realized; the cooling water after water cooling is utilized to heat urea solution, so that the heat of the cooling water is fully utilized, and the heat radiation pressure of the explosion-proof radiator is reduced.

Description

Technical Field

[0001] This invention relates to an explosion-proof temperature control system, specifically to an explosion-proof temperature control system and method for an explosion-proof diesel engine exhaust aftertreatment device. Background Technology

[0002] Explosion-proof diesel engines, as the main power unit for mine mobile transportation equipment, are characterized by high power, strong applicability, and high transportation efficiency. Currently, explosion-proof diesel engines can meet the non-road China III emission standard by applying in-engine purification technologies such as electronic fuel injection systems. However, with the upgrading of emission regulations, simply improving the in-cylinder combustion process to control diesel engine emissions is no longer sufficient to meet the non-road China IV emission standard. Therefore, installing a high-efficiency exhaust aftertreatment device after the explosion-proof diesel engine is an inevitable requirement for upgrading the emission control technology of mining explosion-proof diesel engines.

[0003] Currently, efforts are being made to purify CO, HC, and NO in diesel engine exhaust gases. x Diesel engine exhaust aftertreatment devices primarily utilize technologies such as DOC (Dioxide Catalytic Oxidation), DPF (Distillate Foliar Fluid Extraction), and SCR (Selective Catalytic Reduction) to treat pollutants like carbon soot and particulate matter. However, according to the "Coal Mine Safety Regulations," the surface temperature of any part of an explosion-proof diesel engine must not exceed 150℃. Yet, DOC, SCR, and DPF exhaust aftertreatment devices require a high-temperature reaction environment, far exceeding the explosion-proof requirements in underground coal mines. Therefore, explosion-proof modifications to the aftertreatment devices are necessary to reduce their surface temperature and meet the explosion-proof requirements for underground applications.

[0004] Invention patent 202011108643.X discloses a mine-use explosion-proof diesel engine exhaust gas purification device, proposing to use a water-cooled jacket to provide explosion-proof treatment for the DOC, DPF, and SCR reactors. However, it does not mention the cooling circulation system, nor does it provide specific details on the heating method for the urea solution. In high-latitude, high-altitude coal mines, due to the low winter temperatures, the urea solution in the SCR system begins to freeze below -11℃, causing the SCR system to malfunction. Currently, SCR systems mainly use engine cooling water and electric heating wires to heat and thaw the urea tank; for example, existing patents CN202110373850.6, "An SCR Urea Heating and Thawing Control System and Method," and CN202211395750.4, "An SCR System Temperature Control System and Temperature Control Pressure Buildup Method," both adopt this approach. However, the electric heating equipment in the SCR system can reach temperatures as high as 300℃ during operation, and any electric spark could potentially cause a fire or explosion, failing to meet the explosion-proof requirements of underground coal mines. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides an explosion-proof temperature control system and method for an explosion-proof diesel engine exhaust aftertreatment device. This system meets the explosion-proof requirements of the exhaust aftertreatment device in underground mines, enabling the mine explosion-proof diesel engine to meet the non-road China IV emission standard. It also ensures the normal operating temperature of the urea solution, guaranteeing the normal operation of the SCR reactor underground.

[0006] To achieve the above objectives, the technical solution adopted by this invention is: an explosion-proof temperature control system for an explosion-proof diesel engine exhaust aftertreatment device, comprising an explosion-proof radiator, an explosion-proof water pump, a urea tank temperature sensor, an aftertreatment device water-cooling jacket, a cooling water temperature sensor, an explosion-proof solenoid valve, a urea tank heating pipe, a controller, a thermostat, and a thermostat temperature sensor; the two ends of the aftertreatment device water-cooling jacket are respectively connected to the explosion-proof solenoid valve and the explosion-proof water pump; the explosion-proof solenoid valve is connected to the thermostat in two paths, one path directly connected to the thermostat, and the other path connected to the thermostat through the urea tank heating pipe. The thermostat is connected to the explosion-proof radiator and the explosion-proof water pump respectively. The explosion-proof radiator is connected to the explosion-proof water pump. The urea tank heating tube is located inside the urea tank. The urea tank temperature sensor is built into the urea tank heating tube. The thermostat temperature sensor is built into the thermostat. The cooling water temperature sensor is located at the rear of the water-cooling jacket of the aftertreatment unit. The explosion-proof radiator, thermostat temperature sensor, thermostat, urea tank temperature sensor, cooling water temperature sensor and explosion-proof solenoid valve are all electrically connected to the controller. The thermostat temperature sensor is connected to the thermostat. The urea tank temperature sensor is connected to the urea tank heating tube.

[0007] Furthermore, the water-cooled jacket of the aftertreatment device includes an inlet main pipe, a DOC+DPF water-cooled outer shell, an outlet main pipe, a water-cooled exhaust pipe, a mixer, and an SCR water-cooled outer shell; the rear end of the DOC+DPF water-cooled outer shell is connected to the front end of the SCR water-cooled outer shell through the water-cooled exhaust pipe, the front part of the DOC+DPF water-cooled outer shell, the front part of the water-cooled exhaust pipe, and the front part of the SCR water-cooled outer shell are respectively connected to the inlet main pipe through pipelines, and the rear part of the DOC+DPF water-cooled outer shell, the rear part of the water-cooled exhaust pipe, and the rear part of the SCR water-cooled outer shell are respectively connected to the outlet main pipe through pipelines; a differential pressure sensor is installed at the rear of the DOC+DPF water-cooled outer shell, a urea nozzle is installed on the water-cooled exhaust pipe, a nitrogen-oxygen sensor is installed at the rear of the SCR water-cooled outer shell, and a cooling water temperature sensor is installed at the rear of the outlet main pipe.

[0008] Furthermore, the DOC+DPF water-cooled housing is equipped with a DOC+ heat insulation pad and a DPF+ heat insulation pad inside, and the SCR water-cooled housing is equipped with a mixer and an SCR+ heat insulation pad inside.

[0009] An explosion-proof temperature control method for an explosion-proof diesel engine exhaust aftertreatment device is based on the cooling water temperature of the water-cooled jacket, the urea solution temperature in the urea tank, and the cooling water temperature of the thermostat: When the urea solution temperature in the urea tank is lower than a preset defrosting temperature threshold and the cooling water temperature flowing through the water-cooled jacket of the aftertreatment device is higher than a preset heating temperature threshold, the explosion-proof solenoid valve enters the defrosting working state. The explosion-proof solenoid valve opens and controls the amount of cooling water flowing into the urea tank heating pipe according to the urea solution temperature and the cooling water temperature to heat and defrost the urea solution. The cooling water flows out of the urea tank heating pipe and then flows to the thermostat; when the urea solution temperature in the urea tank ... If the temperature of the hot water or the temperature of the cooling water flowing through the water-cooled jacket of the post-treatment device is lower than the preset heating temperature threshold, the explosion-proof solenoid valve enters the non-thawing working state, the explosion-proof solenoid valve closes, and the cooling water flows directly to the thermostat. When the temperature of the cooling water flowing into the thermostat is higher than the preset heat dissipation temperature threshold, the cooling water enters the large circulation route, the thermostat and the explosion-proof radiator open, and the thermostat controls the amount of cooling water flowing into the explosion-proof radiator according to the cooling water temperature. When the temperature of the cooling water flowing into the thermostat is lower than the preset temperature threshold, the cooling water enters the small circulation route, the explosion-proof radiator closes, and the thermostat returns all the cooling water to the explosion-proof water pump.

[0010] Compared with existing technologies, this invention is based on a water-cooling system for an explosion-proof diesel engine exhaust aftertreatment device, consisting of an explosion-proof water pump, a thermostat, an explosion-proof radiator, and a controller. Circulating cooling water covers the surface of the exhaust aftertreatment device, controlling its surface temperature during operation. The explosion-proof radiator dissipates heat from the cooling water in a timely manner, completing the explosion-proof modification of the exhaust aftertreatment device and enabling its downhole application. A urea heating system is also constructed based on an explosion-proof solenoid valve, a urea tank heating pipe, and a controller. This system, together with the aforementioned water-cooling system, forms a temperature control system for the explosion-proof diesel engine exhaust aftertreatment device. The system uses the cooled water to heat the frozen urea solution, fully utilizing the high temperature of the cooling water while reducing the heat dissipation pressure on the explosion-proof radiator. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the temperature control system structure of the present invention;

[0012] Figure 2 This is a schematic diagram of the water-cooled jacket structure of the post-processing device of the present invention;

[0013] Figure 3 This is a flowchart of the temperature control method of the present invention;

[0014] 1. Explosion-proof radiator; 2. Explosion-proof water pump; 3. Urea tank temperature sensor; 4. Aftertreatment unit water-cooled jacket; 5. Cooling water temperature sensor; 6. Explosion-proof solenoid valve; 7. Urea tank heating tube; 8. Controller; 9. Thermostat; 10. Thermostat temperature sensor; 401. Inlet main pipe; 402. DOC+DPF water-cooled housing; 403. Water-cooled differential pressure sensor; 404. Urea nozzle; 405. Mixer; 406. Nitrogen-oxygen sensor; 407. SCR water-cooled housing; 408. SCR+heat insulation pad; 409. Outlet main pipe; 410. Water-cooled exhaust pipe; 411. DPF+heat insulation pad; 412. DOC+heat insulation pad. Detailed Implementation

[0015] The invention will now be further described with reference to the accompanying drawings.

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] like Figure 1 As shown, the present invention includes an explosion-proof radiator 1, an explosion-proof water pump 2, a urea tank temperature sensor 3, a post-treatment device water-cooling jacket 4, a cooling water temperature sensor 5, an explosion-proof solenoid valve 6, a urea tank heating pipe 7, a controller 8, a thermostat 9, and a thermostat temperature sensor 10; the explosion-proof water pump 2, the post-treatment device water-cooling jacket 4, the explosion-proof solenoid valve 6, the urea tank heating pipe 7, the thermostat 9, and the explosion-proof radiator 1 are connected by cooling water pipes.

[0018] The two ends of the water-cooled jacket 4 of the aftertreatment device are connected to the explosion-proof solenoid valve 6 and the explosion-proof water pump 2, respectively. The explosion-proof solenoid valve 6 is connected to the thermostat 9 in two paths. One path is directly connected to the thermostat 9, and the other path is connected to the thermostat 9 through the urea tank heating pipe 7. The thermostat 9 is connected to the explosion-proof radiator 1 and the explosion-proof water pump 2, respectively. The explosion-proof radiator 1 is connected to the explosion-proof water pump 2. The cooling water circulates under the pressure of the explosion-proof water pump 2 and flows through the water-cooled jacket 4 of the aftertreatment device. The circulating cooling water carries away the heat from the surface of the exhaust gas aftertreatment device, achieving the explosion-proof requirements of the exhaust gas aftertreatment device. The urea tank heating pipe 7 is located inside the urea tank and is heated and thawed by the cooling water flowing through the water-cooled jacket 4 of the aftertreatment device. Figure 2As shown, the water-cooled jacket 4 of the aftertreatment unit includes an inlet main pipe 401, a DOC+DPF water-cooled housing 402, an outlet main pipe 409, a water-cooled exhaust pipe 410, a mixer 405, and an SCR water-cooled housing 407. The rear end of the DOC+DPF water-cooled housing 402 is connected to the front end of the SCR water-cooled housing 407 via the water-cooled exhaust pipe 410. The front part of the DOC+DPF water-cooled housing 402, the front part of the water-cooled exhaust pipe 410, and the front part of the SCR water-cooled housing 407 are respectively connected to the inlet main pipe 401 via pipelines. The rear part of the DOC+DPF water-cooled housing 402, the rear part of the water-cooled exhaust pipe 410, and the rear part of the SCR water-cooled housing 407 are respectively connected to the inlet main pipe 401 via pipelines. Each component is connected to the main outlet pipe 409 via a pipeline; a differential pressure sensor 403 is located at the rear of the DOC+DPF water-cooled housing 402 to detect the pressure difference of the exhaust gas before and after passing through the DPF; a urea nozzle 404 is located on the water-cooled exhaust pipe 410; and a nitrogen oxide sensor 406 is located at the rear of the SCR water-cooled housing 407 to detect the nitrogen oxide concentration of the exhaust gas after passing through the SCR; the DOC+DPF water-cooled housing 402 is equipped with a DOC+insulation pad 412 and a DPF+insulation pad 411 inside, and the SCR water-cooled housing 407 is equipped with a mixer 405 and an SCR+insulation pad 408 inside; the DOC, DPF, and SCR are each wrapped with an insulation pad.

[0019] The urea tank temperature sensor 3 is built into the urea tank heating tube 7, the thermostat temperature sensor 10 is built into the thermostat 9, and the cooling water temperature sensor 5 is located at the rear of the outlet main pipe 409. The explosion-proof radiator 1, thermostat temperature sensor 10, thermostat 9, urea tank temperature sensor 3, cooling water temperature sensor 5, and explosion-proof solenoid valve 6 are all electrically connected to the controller 8. The cooling water temperature sensor 5 collects the temperature data of the cooling water flowing through the water-cooled jacket 4 of the aftertreatment unit and transmits the collected temperature data to the controller 8. The explosion-proof solenoid valve 6 controls the opening of the explosion-proof solenoid valve 6 in the cooling water circulation path by receiving signals from the controller 8, thereby controlling the flow rate of the cooling water path to heat and defrost the urea tank. The urea tank temperature sensor 3 collects the temperature data of the urea solution in the urea tank and transmits the collected temperature data to the controller 8. The thermostat temperature sensor 10 collects the temperature data of the cooling water flowing into the thermostat 9 and transmits the collected temperature data to the controller 8. The thermostat 9 controls the flow rate of the cooling water by receiving signals from the controller 8. The thermostat 9 controls the opening of the cooling water circuit to regulate the flow rate of cooling water to the explosion-proof water pump 2 and the explosion-proof radiator 1. The explosion-proof radiator 1 receives the cooling water from the thermostat 9, dissipates the heat, and then returns it to the explosion-proof water pump 2, thus achieving cooling and circulation of the cooling water. The controller 8 receives the cooling water temperature data of the water-cooled jacket, the urea solution temperature data, and the thermostat cooling water temperature data collected by the cooling water temperature sensor 5, the urea tank temperature sensor 3, and the thermostat temperature sensor 10. Based on the collected cooling water temperature data of the water-cooled jacket, the urea solution temperature data, and the thermostat cooling water temperature data, the controller 8 controls the operation of the explosion-proof solenoid valve 6, the thermostat 9, and the explosion-proof radiator 1.

[0020] like Figure 3 As shown, the explosion-proof water pump 2 is turned on at the same time as the machine is started. The explosion-proof water pump 2 is running throughout the entire process, driving the cooling water to circulate throughout the system. The explosion-proof water pump 2 is connected to the water-cooled jacket 4 of the post-treatment device through a cooling water pipe. In the initial stage of startup, the cooling water temperature is low and no heat dissipation is required. Therefore, after startup, the system defaults to entering the small circulation working state, the explosion-proof radiator 1 is closed, and the cooling water flows directly back to the explosion-proof water pump 2 to enter the next water-cooling cycle.

[0021] After the cooling water flows through the water-cooled jacket 4 of the post-treatment unit, the controller 8 determines whether the urea solution needs heating and whether the cooling water temperature meets the heating conditions based on the urea solution temperature and cooling water temperature data collected by the cooling water temperature sensor 5 and the urea tank temperature sensor 3, respectively. If the urea solution temperature in the urea tank is lower than the preset defrosting temperature threshold, and the cooling water temperature is higher than the preset heating temperature threshold, then the defrosting conditions are met. The explosion-proof solenoid valve 6 and the urea tank heating pipe 7 enter the urea defrosting working state. The explosion-proof solenoid valve 6 opens, and the cooling water flows into the urea tank heating pipe 7 to heat the urea solution in the urea tank, using the high temperature of the cooling water to defrost the urea. Conversely, if the urea solution temperature in the urea tank is higher than the preset defrosting temperature threshold, or the cooling water temperature is lower than the preset heating temperature threshold, then the defrosting conditions are not met. The explosion-proof solenoid valve 6 and the urea tank heating pipe 7 enter the non-defrosting working state. The explosion-proof solenoid valve 6 closes, and the cooling water flows to the thermostat 9 through the pipeline.

[0022] When cooling water flows into the thermostat 9, the controller 8 determines whether to dissipate heat from the cooling water based on the collected cooling water temperature data. If the cooling water temperature of the thermostat is higher than the preset heat dissipation temperature threshold, the system enters the large circulation working state, the thermostat 9 and the explosion-proof radiator 1 open, the cooling water flows through the pipe to the explosion-proof radiator 1 for heat dissipation, and flows back to the explosion-proof water pump 2 after heat dissipation is completed; if the cooling water temperature is lower than the preset heat dissipation temperature threshold, the system enters the small circulation working state, the explosion-proof radiator 1 closes, and the cooling water flows back to the explosion-proof water pump 2 through the pipe.

[0023] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0024] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any minor modifications, equivalent substitutions, and improvements made to the above embodiments based on the technical essence of the present invention should be included within the protection scope of the present invention.

Claims

1. An explosion-proof temperature control system for an explosion-proof diesel engine exhaust aftertreatment device, characterized in that, Includes an explosion-proof radiator (1), an explosion-proof water pump (2), a urea tank temperature sensor (3), a post-treatment device water cooling jacket (4), a cooling water temperature sensor (5), an explosion-proof solenoid valve (6), a urea tank heating tube (7), a controller (8), a thermostat (9), and a thermostat temperature sensor (10). The two ends of the water-cooled jacket (4) of the post-treatment device are connected to the explosion-proof solenoid valve (6) and the explosion-proof water pump (2) respectively. The explosion-proof solenoid valve (6) is connected to the thermostat (9) in two ways. One way is directly connected to the thermostat (9), and the other way is connected to the thermostat (9) through the urea tank heating pipe (7). The thermostat (9) is connected to the explosion-proof radiator (1) and the explosion-proof water pump (2) respectively. The explosion-proof radiator (1) is connected to the explosion-proof water pump (2). The urea tank heating pipe (7) is installed inside the urea tank. The urea tank temperature sensor (3) is built into the urea tank heating tube (7), the thermostat temperature sensor (10) is built into the thermostat (9), the cooling water temperature sensor (5) is located at the rear of the water cooling jacket (4) of the aftertreatment device, the explosion-proof radiator (1), the thermostat temperature sensor (10), the thermostat (9), the urea tank temperature sensor (3), the cooling water temperature sensor (5) and the explosion-proof solenoid valve (6) are all electrically connected to the controller (8), the thermostat temperature sensor (10) is connected to the thermostat (9), and the urea tank temperature sensor (3) is connected to the urea tank heating tube (7); When the temperature of the urea solution in the urea tank is less than the preset defrosting temperature threshold and the temperature of the cooling water flowing through the water-cooled jacket (4) of the post-treatment device is greater than the preset heating temperature threshold, the explosion-proof solenoid valve (6) enters the defrosting working state. The explosion-proof solenoid valve (6) opens and controls the amount of cooling water flowing into the heating pipe (7) of the urea tank according to the temperature of the urea solution and the temperature of the cooling water, so as to heat and defrost the urea solution. The cooling water flows out of the heating pipe (7) of the urea tank and flows to the thermostat (9). When the temperature of the urea solution in the urea tank is greater than the preset heating temperature threshold or the temperature of the cooling water after flowing through the water-cooled jacket (4) of the post-treatment device is less than the preset heating temperature threshold, the explosion-proof solenoid valve (6) enters the non-thawing working state, the explosion-proof solenoid valve (6) closes, and the cooling water flows directly to the thermostat (9). When the temperature of the cooling water flowing into the thermostat (9) is greater than the preset heat dissipation temperature threshold, the cooling water enters the large circulation route, and the thermostat (9) and the explosion-proof radiator (1) are opened. The thermostat (9) controls the amount of cooling water flowing into the explosion-proof radiator (1) according to the cooling water temperature. When the temperature of the cooling water flowing into the thermostat (9) is less than the preset temperature threshold, the cooling water enters the small circulation route, the explosion-proof radiator (1) closes, and the thermostat (9) sends all the cooling water back to the explosion-proof water pump (2).

2. The explosion-proof temperature control system for an explosion-proof diesel engine exhaust aftertreatment device according to claim 1, characterized in that, The water-cooled jacket (4) of the post-treatment device includes an inlet main pipe (401), a DOC+DPF water-cooled shell (402), an outlet main pipe (409), a water-cooled exhaust pipe (410), a mixer (405), and an SCR water-cooled shell (407). The rear end of the DOC+DPF water-cooled housing (402) is connected to the front end of the SCR water-cooled housing (407) via a water-cooled exhaust pipe (410). The front part of the DOC+DPF water-cooled housing (402), the front part of the water-cooled exhaust pipe (410), and the front part of the SCR water-cooled housing (407) are respectively connected to the main water inlet pipe (401) via pipes. The rear part of the DOC+DPF water-cooled housing (402) and the water-cooled exhaust pipe (410) are connected to the main water inlet pipe (401). The rear part of the SCR water-cooled housing (407) is connected to the main outlet pipe (409) through pipes; the differential pressure sensor (403) is located at the rear of the DOC+DPF water-cooled housing (402), the urea nozzle (404) is located on the water-cooled exhaust pipe (410), the nitrogen oxygen sensor (406) is located at the rear of the SCR water-cooled housing (407), and the cooling water temperature sensor (5) is located at the rear of the main outlet pipe (409).

3. The explosion-proof temperature control system for an explosion-proof diesel engine exhaust aftertreatment device according to claim 2, characterized in that, The DOC+DPF water-cooled housing (402) is provided with DOC+ heat insulation pad (412) and DPF+ heat insulation pad (411) inside, and the SCR water-cooled housing (407) is provided with mixer (405) and SCR+ heat insulation pad (408) inside.

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