Exhaust system emission reduction device and emission reduction method

Abstract

The invention discloses an exhaust system emission reduction device and emission reduction method. The system comprises a vehicle-mounted computer, an exhaust aftertreatment system connected with an internal combustion engine, and a heat collection power generation module and a water electrolysis system which are connected with the exhaust aftertreatment system. The water electrolysis system comprises a storage battery connected with the heat collection power generation module, a power generator and a water electrolysis device which are connected with the storage battery, and a main oxygen tank, a standby oxygen tank, a main hydrogen tank and a standby hydrogen tank which are respectively connected with the water electrolysis device and the vehicle-mounted computer; the exhaust aftertreatment system comprises a diesel engine oxidation catalyst and a diesel particle filter which are sequentially arranged in the exhaust gas flow direction, the reaction efficiency is improved through an emission reduction method, and the tail gas treatment efficiency is improved.

Description

Technical Field

[0001] The invention relates to an exhaust system emission reduction device and an emission reduction method, belonging to the technical field of energy saving and emission reduction of internal combustion engines. Background Art

[0002] With the continuous attention paid to exhaust emissions, people have higher and higher requirements for the quality of exhaust treatment. The exhaust treatment processes commonly used in post-treatment exhaust systems are diesel oxidation catalyst (DOC) and diesel particulate filter (DPF). These two exhaust treatment technologies have been widely used. However, in the existing excavator post-treatment exhaust system, the oxygen concentration in DOC and DPF is low, the reaction is not sufficient, and residual exhaust gas will be discharged into the atmosphere. At the same time, if the temperature during the oxidation reaction in DOC and the regeneration of DPF does not reach the oxidation temperature or regeneration temperature, the relevant reactions cannot be completed, and the heat in the exhaust gas is also discharged and not fully utilized. Summary of the invention

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

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

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

[0006] The water electrolysis system comprises a storage battery connected to the heat collection power generation module, a generator and a water electrolysis device connected to the storage battery, a main oxygen tank and a main hydrogen tank connected to the water electrolysis device and the on-board computer respectively; and also comprises a backup oxygen tank connected to the main oxygen tank and the on-board computer, and a backup hydrogen tank connected to the main hydrogen tank and the on-board computer;

[0007] The main oxygen tank and the backup hydrogen tank are connected to the exhaust gas after-treatment system through a one-way throttle valve respectively;

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

[0009] In combination with the first aspect, further, the heat collection power generation module is provided with a plurality of semiconductor temperature difference power generation sheets; and the internal combustion engine is provided with a turbocharger connected to the diesel engine oxidation catalyst.

[0010] Furthermore, the gas outlets of the main oxygen tank and the backup hydrogen tank are provided with electric control valves connected to the on-board computer;

[0011] The diesel particulate filter is provided with a pressure difference sensor and a temperature sensor connected to the on-board computer; the diesel engine oxidation catalyst is provided with a CO concentration sensor, an HC concentration sensor and a temperature sensor connected to the on-board computer.

[0012] In a second aspect, the present application provides an exhaust system emission reduction method, based on any of the above exhaust system emission reduction devices, comprising:

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

[0014] By collecting the volume of carbon particles in the diesel particulate filter and obtaining the amount of oxygen required for the carbon particles to fully react, the on-board computer controls the main oxygen tank to spray oxygen into the diesel particulate filter to eliminate the carbon particles. If the actual temperature of the diesel particulate filter oxidation reaction is lower than the optimal temperature range, the on-board computer controls the main oxygen tank and the main hydrogen tank to spray oxygen and hydrogen into the diesel oxidation catalyst and the diesel particulate filter until the temperature rises to the optimal temperature range for the diesel particulate filter oxidation reaction, and then stops spraying oxygen and hydrogen.

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

[0016] In the working state, 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 reaches full state;

[0017] In the shutdown state, 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 backup oxygen tank or the backup hydrogen tank to be filled into the corresponding main oxygen tank or the 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, drives electricity generation through temperature difference, and stores it in the battery.

[0021] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of any of the above-mentioned methods when executed by a processor.

[0022] In a fourth aspect, the present application provides a mechanical device equipped with any of the above-mentioned exhaust system emission reduction devices.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present application provides an exhaust system emission reduction device and an emission reduction method, which generates oxygen and hydrogen by electrolyzing water, and directly passes oxygen and hydrogen to a diesel engine oxidation catalyst and a diesel particulate filter, thereby increasing the oxygen concentration and the reaction temperature under the condition of hydrogen and oxygen combustion, which not only accelerates the reaction efficiency, but also improves the exhaust gas treatment efficiency;

[0025] At the same time, by collecting heat from the reaction process of the post-treatment system, electricity is generated, the battery is charged, and oxygen and hydrogen are recycled to achieve the effect of energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the exhaust system emission reduction device provided by the embodiment of the present invention;

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

[0028] Figure 3 is a working logic diagram of the exhaust system emission reduction device provided by an embodiment of the present invention, in which hydrogen and oxygen are passed through under different working conditions;

[0029] Figure 4 is a working principle diagram of a heat collection power generation module provided by an embodiment of the present invention;

[0030] In the figure: 1-on-board 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 temperature difference power generation sheet; 12-turbine supercharger; 13-internal combustion engine. DETAILED DESCRIPTION

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

[0032] Embodiment 1:

[0033] like Figure 1 As shown, it is a schematic diagram of an exhaust system emission reduction device provided in this embodiment, including an on-board computer 1, and an internal combustion engine 13, an exhaust after-treatment system, a heat collection power generation module 10 and a water electrolysis system respectively connected to the on-board computer 1 by signal.

[0034] The heat collection power generation module 10 and the water electrolysis system are both connected to the exhaust gas post-treatment system, and the internal combustion engine 13 is linked to the exhaust gas post-treatment system;

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

[0036] The exhaust gas aftertreatment system comprises a diesel oxidation catalyst 9, referred to as DOC, and a diesel particulate filter 8, referred to as DPF, which are arranged in sequence along the exhaust gas flow direction.

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

[0038] The heat collection power generation module 10 is provided with a plurality of semiconductor temperature difference power generation sheets 11. Figure 4 The figure shows the working principle diagram of the thermal power generation module.

[0039] When oxidation reaction occurs in the DOC and DPF is regenerated, the heat collection power generation module is partially inserted into the exhaust pipe of the DOC and DPF, and partially wrapped around the outside of the exhaust pipe, transferring the collected heat to the semiconductor thermoelectric power generation chip. The semiconductor thermoelectric power generation chip generates electricity driven by the temperature difference, and the electricity generated by the semiconductor thermoelectric power generation chip is stored in the battery.

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

[0041] The water electrolysis system includes a battery 3 and a generator 2 for charging, a water 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 for preventing reverse flow of oxygen and hydrogen.

[0042] The water electrolysis device 4 is a device for generating oxygen and hydrogen in the exhaust system emission reduction device, and the water electrolysis device 4 is connected to the DOC and the 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 for use. The gas outlets of the main oxygen tank 52 and the main hydrogen tank 62 are provided with electric control valves. The main storage tank and the exhaust gas post-treatment system are connected through a one-way throttle valve 7. The gas can only flow from the main storage tank to the post-treatment, but not vice versa.

[0044] Embodiment 2:

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

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

[0047] If the construction machinery is running at low load, the engine exhaust temperature will be lower than the preset temperature and 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 sprayed under the control of the ECU. The volume ratio of the oxygen and hydrogen amounts is in the range of 2:1-3:2, preferably 1:2.

[0048] The injected hydrogen and injected oxygen will release heat after the oxidation reaction, which is used to increase the CO and HC oxidation reaction temperature in the DOC until the temperature reaches the temperature at which the CO and HC oxidation reactions are fastest, and then the injection of hydrogen is stopped.

[0049] When the DPF is regenerating, the degree of carbon deposition in the DPF is mainly determined by the differential pressure sensor, the volume of the carbon particles is calculated, and oxygen is injected under the control of the ECU according to the volume of the carbon particles until the differential pressure sensor can no longer detect the carbon particles.

[0050] If it is detected that the temperature in the DPF is lower than the preset temperature, the ECU will control the amount of oxygen and hydrogen sprayed into the DOC and DPF through the one-way throttle valve 7. The temperature of the DOC and DPF will increase after the combustion of hydrogen and oxygen. At the same time, when the gas exhausted from the DOC passes through the DPF, the temperature in the DPF will be increased until the particles in the DPF burn to the set most suitable temperature range, and then the injection of oxygen and hydrogen will be stopped.

[0051] like Figure 2 As shown, it is a working principle diagram of the water electrolysis device 4, including:

[0052] The battery supplies power to the water electrolysis device, which generates oxygen and hydrogen, which are stored in a main oxygen tank and a 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 tank, the water electrolysis device 4 will continuously electrolyze water to generate oxygen and hydrogen to fill the main gas tank in the working state of the mechanical device until the main gas tank reaches a full state;

[0054] When the mechanical device is in shutdown state, if the oxygen and hydrogen obtained by electrolyzing water do not reach 30% of the main gas tank, the oxygen and hydrogen in the alternative gas tank will be filled into the main gas tank;

[0055] Alternative oxygen and hydrogen are stored in alternative gas tanks. When the gas in the alternative gas tanks is less than 30%, the mechanical device instrument panel alarm prompts, and the on-board computer 1 controls the alternative gas tank to be inflated from the outside.

[0056] The present invention mainly detects the concentration changes of CO and HC in DOC by means of CO concentration sensor and HC concentration sensor at all times, and thus injects a proper amount of O2 through a one-way valve under the control of a controller, thereby increasing the oxygen content in the exhaust gas and diluting the exhaust gas, thereby promoting a faster oxidation reaction in the DOC; in the DPF, a pressure difference sensor is mainly used to judge the degree of carbon deposition in the DPF, and when the accumulated value set by the program is reached, a proper amount of O2 and H2 is injected through a one-way valve under the control of the controller, and the injection of O2 and H2 will ignite carbon particles, thereby achieving the purpose of DPF regeneration.

[0057] The above O2 and H2 are collected by a water electrolysis device, which is powered by a battery. A large amount of heat is generated during the reaction of DOC and DPF. The heat is collected by a collector and the heat is used to generate electricity under the action of a semiconductor thermoelectric power generation sheet. The generated electricity is transmitted to the battery. If the battery power is less than 30%, the generator charges the battery under the action of the controller.

[0058] Embodiment three:

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

[0060] The present invention generates oxygen and hydrogen by electrolyzing water, and improves the tail gas treatment efficiency of post-treatment by partially controlling the direct oxygen and hydrogen flow to the DOC and DPF; at the same time, the heat in the post-treatment is collected to generate electricity and the battery is charged, thereby saving energy and achieving the effect of energy saving and emission reduction.

[0061] Improving the DOC reaction efficiency and DPF regeneration efficiency in post-treatment can optimize engine performance, among which improving the DPF regeneration efficiency can save regeneration time and improve operating efficiency during the operation.

Claims

1. An exhaust system emission reduction device, characterized in that: include: An on-board computer (1), an exhaust gas aftertreatment system connected to the internal combustion engine, and a heat collection power generation module (10) and a water electrolysis system respectively connected to the exhaust gas aftertreatment system; The water electrolysis system comprises a storage battery (3) connected to a heat collection power generation module (10), a generator (2) and a water electrolysis device (4) connected to the storage battery (3), a main oxygen tank (52) and a main hydrogen tank (62) connected to the water electrolysis device (4) and an onboard computer (1), respectively; and further comprises a backup oxygen tank (51) connected to the main oxygen tank (52) and the onboard computer (1), and a backup hydrogen tank (61) connected to the main hydrogen tank (62) and the onboard computer (1); The main oxygen tank (52) and the main hydrogen tank (62) are respectively connected to the exhaust gas aftertreatment system via a one-way throttle valve (7); The exhaust gas aftertreatment system comprises a diesel oxidation catalyst (9) and a diesel particulate filter (8) arranged along the exhaust gas flow direction.

2. The exhaust system emission reduction device according to claim 1, characterized in that: The heat collection power generation module (10) is provided with a plurality of semiconductor temperature difference power generation sheets (11); and the internal combustion engine is provided with a turbocharger (12) connected to the diesel engine oxidation catalyst (9).

3. The exhaust system emission reduction device according to claim 1, characterized in that: The gas outlets of the main oxygen tank (52) and the main hydrogen tank (62) are provided with electric control valves connected to the on-board computer (1); The diesel particulate filter (8) is provided with a pressure difference sensor and a temperature sensor connected to the onboard computer (1); the diesel engine oxidation catalyst (9) is provided with a CO concentration sensor, an HC concentration sensor and a temperature sensor connected to the onboard computer (1).

4. A method for reducing emissions from an exhaust system, characterized in that: The exhaust system emission reduction device according to any one of claims 1 to 3 comprises: By collecting the concentrations of CO and HC in the diesel oxidation catalyst (9), the amount of oxygen required for the oxidation reaction in the diesel oxidation catalyst (9) is obtained, and the on-board computer (1) controls the main oxygen tank (52) to spray oxygen into the diesel oxidation catalyst (9); if the actual temperature of the oxidation reaction in the diesel 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 spray oxygen and hydrogen into the diesel oxidation catalyst (9) until the temperature is raised to the optimal temperature range for the oxidation reaction in the diesel oxidation catalyst (9), wherein the volume ratio of the 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, and the on-board computer (1) controls the main oxygen tank (52) to spray oxygen into the diesel particulate filter (8) to eliminate the carbon particles; if the actual temperature of the oxidation reaction of the diesel particulate filter (8) is lower than the optimal temperature range, the on-board computer (1) controls the main oxygen tank (52) and the main hydrogen tank (62) to spray 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 for the oxidation reaction of the diesel particulate filter (8), and then stops spraying oxygen and hydrogen.

5. The emission reduction method according to claim 4, characterized in that: The emission reduction method also includes: In the working state, if the oxygen in the main oxygen tank (52) or the hydrogen in the main hydrogen tank (62) is less than a preset volume, the onboard 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 a full state; 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 a preset volume, the onboard computer (1) controls the oxygen tank (51) or the spare hydrogen tank (61) to be filled into the corresponding main oxygen tank (52) or main hydrogen tank (62).

6. The emission reduction method according to claim 5, characterized in that: The preset volume is 30% of the volume of the main oxygen tank (52) or the main hydrogen tank (62).

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

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of any method described in claims 4-7 are implemented.

9. A mechanical device, characterized in that: An exhaust system emission reduction device as described in any one of claims 1 to 3 is installed.

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