An exhaust system emission reduction device and method

Abstract

This invention discloses an exhaust system emission reduction device and method. The system includes an on-board computer, an exhaust aftertreatment system connected to an internal combustion engine, and a thermal power generation module and an electrolysis water system respectively connected to the exhaust aftertreatment system. The electrolysis water system includes a battery connected to the thermal power generation module, a generator connected to the battery, and an electrolysis water device, as well as a main oxygen tank and a backup oxygen tank, a main hydrogen tank and a backup hydrogen tank respectively connected to the electrolysis water device and the on-board computer. The exhaust aftertreatment system includes a diesel engine oxidation catalyst and a diesel particulate filter arranged sequentially along the exhaust gas flow direction. The emission reduction method accelerates the reaction efficiency and improves the exhaust gas treatment efficiency.

Description

Technical Field

[0001] This invention relates to an exhaust system emission reduction device and method, belonging to the field of energy conservation and emission reduction technology for internal combustion engines. Background Technology

[0002] With increasing emphasis on exhaust emissions, the requirements for exhaust gas treatment quality are also rising. Commonly used aftertreatment exhaust systems employ diesel oxidation catalysts (DOC) and diesel particulate filters (DPF), both of which are widely applied. However, existing excavator aftertreatment exhaust systems suffer from low oxygen concentrations in the DOC and DPF, leading to incomplete reactions and residual exhaust gases being released into the atmosphere. Furthermore, if the oxidation reaction in the DOC and the regeneration of the DPF do not reach the required temperatures, the reactions cannot be completed, and heat from the exhaust gases is also released without being fully utilized. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide an exhaust system emission reduction device and method to solve the problems of insufficient oxygen concentration and excessively low reaction temperature.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] In a first aspect, this application provides an exhaust system emission reduction device, including: an on-board computer, an exhaust aftertreatment system connected to an internal combustion engine, and a thermal power generation module and an electrolysis water system respectively connected to the exhaust aftertreatment system;

[0006] The water electrolysis system includes a battery connected to the thermal power generation module, a generator connected to the battery, and a water electrolysis device, a main oxygen tank and a main hydrogen tank connected to the water electrolysis device and the vehicle computer, respectively; it also includes a backup oxygen tank connected to the main oxygen tank and the vehicle computer, and a backup hydrogen tank connected to the main hydrogen tank and the vehicle computer.

[0007] The main oxygen tank and the backup hydrogen tank are respectively connected to the exhaust aftertreatment system via one-way throttle valves;

[0008] The exhaust aftertreatment system includes a diesel engine oxidation catalyst and a diesel particulate filter arranged sequentially along the exhaust gas flow direction.

[0009] In conjunction with the first aspect, the thermal power generation module is further provided with a plurality of semiconductor thermoelectric generators; the internal combustion engine is provided with a turbocharger connected to the diesel engine oxidation catalyst.

[0010] Furthermore, the outlets of the main oxygen tank and the backup hydrogen tank are equipped with electronically controlled valves connected to the vehicle's computer.

[0011] The diesel particulate filter is equipped with a differential pressure sensor and a temperature sensor connected to the vehicle's computer; the diesel engine oxidation catalyst is equipped with a CO concentration sensor, an HC concentration sensor, and a temperature sensor connected to the vehicle's computer.

[0012] Secondly, this application provides an exhaust system emission reduction method, based on any of the exhaust system emission reduction devices described above, comprising:

[0013] By collecting the concentrations of CO and HC in the diesel engine oxidation catalyst, the amount of oxygen required for the oxidation reaction in the diesel engine oxidation catalyst is obtained. The on-board computer controls the main oxygen tank to inject oxygen into the diesel engine oxidation catalyst. If the actual temperature of the oxidation reaction in the diesel engine oxidation catalyst is lower than the optimal temperature range, the on-board computer controls the main oxygen tank and the main hydrogen tank to inject oxygen and hydrogen into the diesel engine oxidation catalyst until the temperature rises to the optimal temperature range of the diesel engine oxidation catalyst oxidation reaction. The volume ratio of injected oxygen to hydrogen is in the range of 2:1-3:2.

[0014] By collecting the volume of carbon particles in the diesel particulate filter, the amount of oxygen required for the carbon particles to fully react is obtained. The onboard computer controls the main oxygen tank to inject oxygen into the diesel particulate filter to eliminate the carbon particles. If the actual temperature of the oxidation reaction in the diesel particulate filter is lower than the optimal temperature range, the onboard computer controls the main oxygen tank and main hydrogen tank to inject oxygen and hydrogen into the diesel engine oxidation catalyst and diesel particulate filter until the temperature rises to the optimal temperature range for the oxidation reaction in the diesel particulate filter, at which point the injection of oxygen and hydrogen stops.

[0015] In conjunction with the second aspect, the emission reduction method further includes:

[0016] In operation, if the oxygen in the main oxygen tank or the hydrogen in the main hydrogen tank is less than the preset volume, the on-board computer controls the water electrolysis device to electrolyze water to generate oxygen or hydrogen until the oxygen in the main oxygen tank or the hydrogen in the main hydrogen tank is full.

[0017] When the engine is stopped, if the oxygen in the main oxygen tank or the hydrogen in the main hydrogen tank is less than the preset volume, the onboard computer will control the backup oxygen tank or backup hydrogen tank to fill the corresponding main oxygen tank or main hydrogen tank.

[0018] Furthermore, the preset volume is 30% of the volume of the main oxygen tank or the main hydrogen tank.

[0019] Furthermore, the emission reduction method includes:

[0020] The thermal power generation module collects the heat from the reaction of the diesel particulate filter and the diesel engine oxidation catalyst, and generates electricity through the temperature difference, which is stored in the battery.

[0021] Thirdly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the methods described above.

[0022] Fourthly, this application provides a mechanical device equipped with any of the exhaust system emission reduction devices described above.

[0023] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0024] This application provides an exhaust system emission reduction device and method, which generates oxygen and hydrogen by electrolyzing water and directly introduces oxygen and hydrogen into the diesel engine oxidation catalyst and diesel particulate filter. This not only increases the oxygen concentration but also increases the reaction temperature under hydrogen-oxygen combustion conditions, thereby accelerating the reaction efficiency and improving the exhaust gas treatment efficiency.

[0025] Simultaneously, by collecting heat during the reaction process of the after-treatment system to generate electricity, the battery is charged and recycled to produce oxygen and hydrogen, achieving the effect of energy conservation and emission reduction. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the exhaust system emission reduction device provided in this invention.

[0027] Figure 2 This is a schematic diagram of the working principle of the water electrolysis device provided in the embodiment of the present invention;

[0028] Figure 3 This is a working logic diagram of the exhaust system emission reduction device provided in this embodiment of the invention, under different operating conditions, for passing hydrogen and oxygen;

[0029] Figure 4 This is a schematic diagram of the working principle of the thermal power generation module provided in the embodiment of the present invention;

[0030] In the diagram: 1-Onboard computer; 2-Generator; 3-Battery; 4-Water electrolysis device; 51-Spare oxygen tank; 52-Main oxygen tank; 61-Spare hydrogen tank; 62-Main hydrogen tank; 7-One-way throttle valve; 8-Diesel particulate filter; 9-Diesel engine oxidation catalyst; 10-Thermal power generation module; 11-Semiconductor thermoelectric generator; 12-Turbocharger; 13-Internal combustion engine. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0032] Example 1:

[0033] like Figure 1 The diagram shown is a schematic of an exhaust system emission reduction device provided in this embodiment, including an on-board computer 1, an internal combustion engine 13, an exhaust aftertreatment system, a thermal power generation module 10, and an electrolysis water system, all of which are connected to the on-board computer 1 via signals.

[0034] Among them, the thermal power generation module 10 and the water electrolysis system are both connected to the exhaust aftertreatment system, and the internal combustion engine 13 is linked to the exhaust aftertreatment system.

[0035] The internal combustion engine 13 includes a turbocharger 12.

[0036] The exhaust aftertreatment system includes a diesel engine oxidation catalyst 9, abbreviated as DOC, and a diesel particulate filter 8, abbreviated as DPF, arranged sequentially along the exhaust gas flow direction.

[0037] Furthermore, the DOC is equipped with a CO concentration sensor, an HC concentration sensor, and a temperature sensor connected to the vehicle computer 1; the DPF is equipped with a differential pressure sensor and a temperature sensor connected to the vehicle computer 1.

[0038] The thermal power generation module 10 is equipped with a plurality of semiconductor thermoelectric generators 11. For example Figure 4 The diagram shown is a schematic of the working principle of a thermal power generation module.

[0039] During the oxidation reaction in the DOC and the regeneration of the DPF, the thermal power generation module is partially inserted into the exhaust pipes of the DOC and DPF, and partially wrapped around the outside of the exhaust pipes. It transfers the collected heat to the thermoelectric generator, which generates electricity driven by the temperature difference. The electricity generated by the thermoelectric generator is stored in the battery.

[0040] In this embodiment, when the battery charge is below 30%, the generator in the engineering machinery power system charges the battery. The battery can also be charged by connecting to an external power source via a charger.

[0041] The water electrolysis system includes a storage battery 3 and a generator 2 for charging, an electrolysis device 4, a main oxygen tank 52 and a backup oxygen tank 51 for storing oxygen generated by the water electrolysis device 4, a main hydrogen tank 62 and a backup hydrogen tank 61 for storing hydrogen, and a one-way throttle valve 7 to prevent oxygen and hydrogen from flowing in opposite directions.

[0042] Among them, the water electrolysis device 4 is a device that generates oxygen and hydrogen in the exhaust system emission reduction device, and the water electrolysis device 4 is connected to DOC and DPF.

[0043] Specifically, the water electrolysis device 4 electrolyzes oxygen and hydrogen, which are stored in the main oxygen tank 52 and the main hydrogen tank 62 respectively for later use. The outlets of the main oxygen tank 52 and the main hydrogen tank 62 are equipped with electrically controlled valves. The main storage tank and the exhaust after-treatment system are connected by a one-way throttle valve 7. The gas can only flow from the main storage tank to the after-treatment system, and vice versa.

[0044] Example 2:

[0045] like Figure 3 As shown in the figure, the working logic diagram of the exhaust system emission reduction device provided in this embodiment of the invention under different operating conditions for passing hydrogen and oxygen is as follows:

[0046] During normal operation, the concentrations of CO and HC in DOC are constantly monitored by CO and HC concentration sensors. The amount of oxygen required for the oxidation reaction is calculated in the on-board computer 1 (Electronic Control Unit, or ECU). Under the control of the ECU, the electronically controlled valve of the main oxygen tank 52 is opened to inject the amount of oxygen required for the oxidation reaction, thereby increasing the oxygen content in the exhaust gas and diluting the exhaust gas.

[0047] If the construction machinery is running under low load, causing the engine exhaust temperature to be lower than the preset temperature, the DOC reaction speed will slow down. At this time, the temperature in the DOC is collected. If the temperature is lower than the optimal temperature range for the oxidation reaction of CO and HC, oxygen and hydrogen are injected under the control of the ECU. The volume ratio of the oxygen to hydrogen is in the range of 2:1-3:2, preferably 1:2.

[0048] The injected hydrogen and oxygen react to form an oxidation reaction, releasing heat to raise the temperature of the CO and HC oxidation reaction in the DOC until the temperature reaches the point where the CO and HC oxidation reaction rate is fastest, at which point the injection of hydrogen stops.

[0049] During DPF regeneration, the degree of carbon buildup in the DPF is mainly determined by a differential pressure sensor. The volume of carbon particles is calculated and obtained. Based on the volume of carbon particles, oxygen is injected under the control of the ECU until the differential pressure sensor can no longer detect carbon particles.

[0050] If the temperature in the DPF is detected to be lower than the preset temperature, the ECU will control the amount of oxygen and hydrogen injected into the DOC and DPF through the one-way throttle valve 7. After the hydrogen and oxygen in the DOC and DPF burn, the temperature will increase. At the same time, when the gas discharged from the DOC passes through the DPF, it will increase the temperature in the DPF until the particles in the DPF burn to the set optimal temperature range, and then the injection of oxygen and hydrogen will stop.

[0051] like Figure 2 The diagram shown illustrates the working principle of the water electrolysis device 4, which includes:

[0052] The battery supplies power to the water electrolysis device, which generates oxygen and hydrogen, which are stored in the main oxygen tank and the main hydrogen tank, respectively.

[0053] If the oxygen in the main oxygen tank 52 or the hydrogen in the main hydrogen tank 62 is less than 30% of the main gas storage tank, the water electrolysis device 4 will continuously electrolyze water to generate oxygen and hydrogen to fill the main gas storage tank in the mechanical device working state until the main gas storage tank reaches the full state.

[0054] When the mechanical device is stopped, if the oxygen and hydrogen obtained from water electrolysis do not reach 30% of the main storage tank, then the oxygen and hydrogen in the alternative storage tank will be added to the main storage tank.

[0055] Alternative oxygen and hydrogen are stored in alternative gas tanks. When the gas in the alternative gas tank is less than 30%, the mechanical instrument panel will issue an alarm, and the on-board computer 1 will control the alternative gas tank to be filled with gas from the outside.

[0056] This invention primarily uses CO and HC concentration sensors to continuously monitor changes in CO and HC concentrations in DOC. Under the control of a controller, an appropriate amount of O2 is injected through a one-way valve to increase the oxygen content in the exhaust gas while also diluting it, thus promoting faster oxidation reactions in the DOC. In the DPF, a differential pressure sensor is used to determine the degree of carbon buildup. When the accumulated value is reached, an appropriate amount of O2 and H2 is injected through a one-way valve under the control of a controller. The injected O2 and H2 ignite the carbon particles, achieving the purpose of DPF regeneration.

[0057] The aforementioned O2 and H2 are collected by a water electrolysis device powered by a battery. During the reaction of DOC and DPF, a large amount of heat is generated. The heat is collected by a collector and used to generate electricity through a thermoelectric generator. The generated electricity is transferred to the battery. If the battery charge is below 30%, the generator charges the battery under the control of the controller.

[0058] Example 3:

[0059] This embodiment provides a mechanical device on which the exhaust system emission reduction device described in Embodiment 1 is installed.

[0060] This invention generates oxygen and hydrogen through water electrolysis, and improves the efficiency of exhaust gas treatment by partially controlling the direct oxygen and hydrogen flow to DOC and DPF. At the same time, it generates electricity by collecting heat from the post-treatment process to charge the battery, thereby saving energy and achieving the effect of energy conservation and emission reduction.

[0061] Improving the DOC reaction efficiency and DPF regeneration efficiency in aftertreatment can optimize engine performance. In particular, improving DPF regeneration efficiency can save regeneration time and improve operational efficiency during the process.

Claims

1. A method for reducing emissions in an exhaust system, characterized in that, Based on an exhaust system emission reduction device, the device includes: an on-board computer (1), an exhaust aftertreatment system connected to an internal combustion engine, and a thermal power generation module (10) and an electrolysis water system respectively connected to the exhaust aftertreatment system; The water electrolysis system includes a battery (3) connected to the thermal power generation module (10), a generator (2) connected to the battery (3), and a water electrolysis device (4), a main oxygen tank (52) and a main hydrogen tank (62) connected to the water electrolysis device (4) and the vehicle computer (1), respectively; it also includes a spare oxygen tank (51) connected to the main oxygen tank (52) and the vehicle computer (1), and a spare hydrogen tank (61) connected to the main hydrogen tank (62) and the vehicle computer (1); The exhaust aftertreatment system includes a diesel engine oxidation catalyst (9) and a diesel particulate filter (8) arranged along the exhaust gas flow direction. The main oxygen tank (52) and the main hydrogen tank (62) are connected to the diesel engine oxidation catalyst (9) and the diesel particulate filter (8) respectively through pipelines and one-way throttle valves (7). The method includes: By collecting the concentrations of CO and HC in the diesel engine oxidation catalyst (9), the amount of oxygen required for the oxidation reaction in the diesel engine oxidation catalyst (9) is obtained. The on-board computer (1) controls the main oxygen tank (52) to inject oxygen into the diesel engine oxidation catalyst (9). If the actual temperature of the oxidation reaction in the diesel engine oxidation catalyst (9) is lower than the optimal temperature range, the on-board computer controls the main oxygen tank (52) and the main hydrogen tank (62) to inject oxygen and hydrogen into the diesel engine oxidation catalyst (9) until the temperature rises to the optimal temperature range of the oxidation reaction in the diesel engine oxidation catalyst (9). The volume ratio of injected oxygen and hydrogen is in the range of 2:1-3:

2. By collecting the volume of carbon particles in the diesel particulate filter (8), the amount of oxygen required for the carbon particles to fully react is obtained. The vehicle computer (1) controls the main oxygen tank (52) to inject oxygen into the diesel particulate filter (8) to eliminate carbon particles. If the actual temperature of the regeneration reaction of the diesel particulate filter (8) is lower than the optimal temperature range, the vehicle computer (1) controls the main oxygen tank (52) and the main hydrogen tank (62) to inject oxygen and hydrogen into the diesel engine oxidation catalyst (9) and the diesel particulate filter (8) until the temperature rises to the optimal temperature range of the oxidation reaction of the diesel particulate filter (8), and then stops injecting oxygen and hydrogen.

2. The emission reduction method according to claim 1, characterized in that, The emission reduction methods also include: In operation, if the oxygen in the main oxygen tank (52) or the hydrogen in the main hydrogen tank (62) is less than the preset volume, the vehicle computer (1) controls the water electrolysis device (4) to electrolyze water to generate oxygen or hydrogen until the oxygen in the main oxygen tank (52) or the hydrogen in the main hydrogen tank (62) reaches full capacity. In the shutdown state, if the oxygen in the main oxygen tank (52) or the hydrogen in the main hydrogen tank (62) is less than the preset volume, the on-board computer (1) controls the backup oxygen tank (51) or backup hydrogen tank (61) to fill the corresponding main oxygen tank (52) or main hydrogen tank (62).

3. The emission reduction method according to claim 2, characterized in that, The preset volume is 30% of the volume of the main oxygen tank (52) or the main hydrogen tank (62).

4. The emission reduction method according to claim 1, characterized in that, The emission reduction methods include: The thermal power generation module (10) collects the heat generated by the reaction of the diesel particulate filter (8) and the diesel engine oxidation catalyst (9), and generates electricity through temperature difference, which is stored in the battery (3).

5. The emission reduction method according to claim 1, characterized in that, The thermal power generation module (10) is provided with a number of semiconductor thermoelectric generators (11); the internal combustion engine is provided with a turbocharger (12) connected to the diesel engine oxidation catalyst (9).

6. The emission reduction method according to claim 1, characterized in that, The outlets of the main oxygen tank (52) and the main hydrogen tank (62) are equipped with electronically controlled valves connected to the on-board computer (1); The diesel particulate filter (8) is equipped with a differential pressure sensor and a temperature sensor connected to the vehicle computer (1); the diesel engine oxidation catalyst (9) is equipped with a CO concentration sensor, an HC concentration sensor and a temperature sensor connected to the vehicle computer (1).

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the method described in any one of claims 1-6.

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