Tail gas after-treatment mechanism, engine system and working machine
By monitoring the engine coolant temperature and controlling the exhaust gas recirculation, the problem of insufficient catalyst temperature during the cold start phase was solved, achieving efficient catalyst operation and energy saving.
Patent Information
- Application Number
- CN202422691061.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-05
- Publication Date
- 2025-12-16
- Estimated Expiration
- 2034-11-05
AI Technical Summary
During the cold start phase, the exhaust gas temperature is low, which cannot meet the high conversion efficiency requirements of the catalyst carrier, resulting in low catalyst efficiency and energy waste.
By installing a first temperature sensor to monitor the engine coolant temperature, and using a controller to control the recovery unit to return the exhaust gas from the catalytic unit outlet to the intake end, the catalyst temperature is increased, thus meeting the high conversion efficiency requirements of the catalyst carrier.
Rapidly increasing catalyst temperature during cold starts improves engine exhaust gas conversion efficiency, reduces energy waste, and lowers emissions and costs.
Smart Images
Figure CN223676358U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to tail gas emission technical field especially relates to a tail gas aftertreatment mechanism, engine system and operation machine. BACKGROUND
[0002] With the engine possession amount gradually increasing, environmental pollution problem is increasingly serious, for further improvement air quality, engine is arranged catalytic structure in aftertreatment.
[0003] In the related art, the catalytic structure is used to treat the tail gas of the engine, and the catalytic structure includes a shell and a catalyst carrier packaged in the shell. As is known, the conversion efficiency of the catalyst carrier to the tail gas is closely related to the temperature of the tail gas.
[0004] However, when the engine is in the cold start stage, the temperature of the tail gas is low, which cannot meet the required temperature for the catalyst carrier to work at high conversion efficiency. SUMMARY
[0005] The utility model provides a kind of tail gas aftertreatment mechanism, engine system and operation machine to solve the defect that the temperature of the tail gas of engine cold start stage in prior art is low, cannot meet the temperature required for high conversion efficiency of catalyst carrier.
[0006] The utility model provides a kind of tail gas aftertreatment mechanism, comprising:
[0007] First temperature sensor, installation is in engine, the first temperature sensor is used to monitor the coolant temperature of the engine;
[0008] Catalytic unit, the air inlet end of the catalytic unit is connected to the exhaust end of the engine;
[0009] Recovery unit, the air outlet end of the recovery unit is connected to the air inlet end of the catalytic unit, and the air inlet end of the recovery unit is connected to the air outlet end of the catalytic unit;
[0010] Controller, the controller is connected to the first temperature sensor, the controller is used to control the air inlet end and air outlet end of the recovery unit open when the coolant temperature is lower than temperature preset value, so that at least part of the tail gas of the air outlet end of the catalytic unit is backflowed to the air inlet end of the catalytic unit through the recovery unit, and the air inlet end and air outlet end of the recovery unit are closed when the coolant temperature is higher than or equal to temperature preset value, so that all tail gas of the air outlet end of the catalytic unit is discharged into atmosphere.
[0011] According to the utility model provides a kind of tail gas aftertreatment mechanism, the recovery unit includes:
[0012] A first control valve, a first inlet end of the first control valve being connected to an exhaust end of the engine, an outlet end of the first control valve being connected to an inlet end of the catalytic unit;
[0013] A control pump, an outlet end of the control pump being connected to a second inlet end of the first control valve;
[0014] A second control valve, an inlet end of the second control valve being connected to an outlet end of the catalytic unit, a first outlet end of the second control valve being connected to an inlet end of the control pump, a second outlet end of the second control valve being connected to the atmosphere;
[0015] The controller is connected to the first control valve, the control pump and the second control valve.
[0016] According to the tail gas aftertreatment mechanism, the recovery unit comprises connection to:
[0017] A variable diameter pipe, an inlet end of the variable diameter pipe being connected to an outlet end of the catalytic unit, an outlet end of the variable diameter pipe being connected to an inlet end of the catalytic unit, a diameter of the variable diameter pipe gradually decreasing from the inlet end to the outlet end;
[0018] A first control valve is arranged at the outlet end of the variable diameter pipe;
[0019] A second control valve is arranged at the inlet end of the variable diameter pipe.
[0020] According to the tail gas aftertreatment mechanism, the first control valve is an on-off valve, and the second control valve is a flow regulating valve.
[0021] According to the tail gas aftertreatment mechanism, the catalytic unit comprises an oxidation catalyst, a particulate trap and a catalytic reducer which are sequentially arranged along the airflow direction.
[0022] According to the tail gas aftertreatment mechanism, a second temperature sensor is arranged at the oxidation catalyst, and the controller is connected to the second temperature sensor.
[0023] According to the tail gas aftertreatment mechanism, the outlet end of the catalytic unit is provided with a pressure sensor connected to the controller.
[0024] According to the tail gas aftertreatment mechanism, the inner wall of the pore channel of the particulate trap is coated with a noble metal catalyst, and the noble metal catalyst comprises at least one of Pt, Pd and Rh.
[0025] The utility model also provides an engine system, including engine and the tail gas post processing mechanism of any one described above, the air inlet end of catalytic unit is connected in the air outlet end of engine.
[0026] The utility model also provides a working machine, including the engine system of above.
[0027] The utility model discloses an engine system, including engine and the tail gas post processing mechanism of any one described above, the air inlet end of catalytic unit is connected in the air outlet end of engine. BRIEF DESCRIPTION OF DRAWINGS
[0028] In order to more clearly illustrate the technical scheme in the utility model or prior art, the following will be to the drawing needed to be used in the embodiment or prior art description a simple introduction, obviously, the following description in the drawing is some embodiments of the utility model, for those skilled in the art, under the premise of not paying creative labor, can also obtain other drawings according to these drawings.
[0029] Figure 1 It is one of the structure schematic diagram of the tail gas post processing mechanism provided by the utility model.
[0030] Figure 2 It is the structure schematic diagram of the tail gas post processing mechanism provided by the utility model.
[0031] REFERENCE NUMERALS
[0032] 100, first temperature sensor;200, catalytic unit;210, oxidation catalytic converter;220, particulate trap;230, catalytic reducer;300, recovery unit;310, first control valve;320, control pump;330, second control valve;400, controller;500, second temperature sensor;600, engine. DETAILED DESCRIPTION
[0033] The embodiment of the utility model is further described in detail in combination with the drawings and examples.The following examples are used to illustrate the utility model, but can not be used to limit the scope of the utility model.
[0034] In the description of the embodiments of the utility model, it needs to be explained that, the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the embodiments of the utility model and simplifying the description, and therefore cannot be understood as limiting the embodiments of the utility model. The terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.
[0035] In the description of the embodiments of the utility model, it needs to be explained that, unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be indirectly connected through an intermediate medium. For ordinary skilled in the art, the specific meaning of the above terms in the embodiments of the utility model can be understood according to the specific circumstances.
[0036] In the embodiments of the utility model, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "above" and "above" of the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" of the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.
[0037] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the utility model. In the present application, the illustrative description of the above terms is not necessarily for the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, the skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of different embodiments or examples without contradiction.
[0038] The embodiments of the first aspect of the utility model propose a tail gas aftertreatment mechanism, Figure 1The utility model discloses an exhaust gas aftertreatment mechanism and an engine provided with the same. Figure 1 As shown in the figure, the exhaust gas aftertreatment mechanism comprises a first temperature sensor 100, a catalytic unit 200, a recovery unit 300 and a controller 400.
[0039] The first temperature sensor 100 is installed on the engine 600 and is used to monitor the coolant temperature of the engine 600; the air inlet end of the catalytic unit 200 is connected to the air outlet end of the engine 600; the two ends of the recovery unit 300 are respectively connected to the air inlet end of the catalytic unit 200 and the air outlet end of the catalytic unit 200, specifically, the air outlet end of the recovery unit 300 is connected to the air inlet end of the catalytic unit 200, and the air inlet end of the recovery unit 300 is connected to the air outlet end of the catalytic unit 200; the controller 400 is connected to the first temperature sensor 100, the controller 400 acquires the coolant temperature monitored by the first temperature sensor 100, and the controller 400 controls the action of the recovery unit 300 based on the coolant temperature.
[0040] Specifically, the controller 400 is used to control the air inlet end and the air outlet end of the recovery unit 300 to be opened when the coolant temperature is lower than a temperature preset value, so that at least part of the exhaust gas at the air outlet end of the catalytic unit 200 is backflowed to the air inlet end of the catalytic unit 200 through the recovery unit 300, and the controller 400 is used to control the air inlet end and the air outlet end of the recovery unit 300 to be closed when the coolant temperature is higher than or equal to the temperature preset value, so that all the exhaust gas at the air outlet end of the catalytic unit 200 is discharged into the atmosphere.
[0041] It can be understood that the coolant temperature of the engine 600 is monitored by using the first temperature sensor 100, and whether the engine 600 is in a cold start state is monitored based on the coolant temperature; when the coolant temperature is too low and lower than the temperature preset value, the engine 600 is in the cold start state at this time, and the controller 400 controls the action of the recovery unit 300 to backflow the exhaust gas at the air outlet end of the catalytic unit 200 to the air inlet end of the catalytic unit 200 through the recovery unit 300.
[0042] The engine 600 is in the cold start state, the fuel is not fully combusted in the engine, the exhaust gas after the catalytic reaction of the catalytic unit 200 contains a large amount of uncombusted HC (hydrocarbon) and CO (carbon oxide), the exhaust gas at the air outlet end of the catalytic unit 200 is sent to the air inlet end of the catalytic unit 200 again, the exhaust gas discharged by the catalytic unit 200 can be utilized under the cold start state to quickly increase the catalyst temperature and reduce the light-off time.
[0043] When the coolant temperature of the engine 600 monitored by the first temperature sensor 100 is higher than or equal to the temperature preset value, the engine 600 is in a non-cold start state at this time and is in a stable working state, so that all the exhaust gas at the air outlet end of the catalytic unit 200 is discharged into the atmosphere.
[0044] The tail gas post-processing mechanism provided by the embodiment of the utility model, through the first temperature sensor 100 monitoring the cooling liquid temperature of the engine 600, the controller 400 obtains the cooling liquid temperature, when the cooling liquid temperature is lower than the temperature preset value, the engine 600 is in the cold start state, the tail gas after the catalytic reaction of the catalytic unit 200 is backflowed to the air inlet end of the catalytic unit 200 through the recovery unit 300, so as to improve the catalyst temperature and meet the catalyst carrier work of the catalytic unit 200 in the high conversion efficiency, and further improve the conversion efficiency of the engine 600 exhaust.
[0045] It needs to be explained that the engine 600 is in the cold start state, the tail gas of the air outlet end of the catalytic unit 200 contains a large amount of unburned HC and CO, and if directly discharged, energy waste will be caused. The utility model utilizes the tail gas when the engine is cold started, can quickly improve the catalyst temperature under the cold start state, and further improves the catalytic conversion efficiency while reducing energy waste, achieves the purpose of energy saving and emission reduction and reduces the emission.
[0046] It needs to be explained that in the related art, the way for quickly improving the catalyst temperature is to improve the engine 600 speed, delay the oil injection advance angle, improve the oil injection amount and the like, however, the oil consumption in the cold start stage will also increase in this way, thereby increasing the cost, and a large amount of unburned tail gas is discharged, further increasing the energy waste. The utility model utilizes the tail gas when the engine is cold started, can save the cost and reduce the energy waste.
[0047] In an embodiment of the utility model, the recovery unit 300 includes a first control valve 310, a control pump 320 and a second control valve 330, the first inlet end of the first control valve 310 is connected to the exhaust end of the engine 600, the outlet end of the first control valve 310 is connected to the air inlet end of the catalytic unit 200; the outlet end of the control pump 320 is connected to the second inlet end of the first control valve 310; the inlet end of the second control valve 330 is connected to the air outlet end of the catalytic unit 200, the first outlet end of the second control valve 330 is connected to the inlet end of the control pump 320, and the second outlet end of the second control valve 330 is connected to the atmosphere; the controller 400 is connected to the first control valve 310, the control pump 320 and the second control valve 330.
[0048] It can be understood that when the coolant temperature is too low and lower than the temperature preset value, the engine 600 is in a cold start state, the controller 400 controls the first control valve 310, the control pump 320 and the second control valve 330 to be opened; the first inlet end of the first control valve 310 and the outlet end of the first control valve 310 are communicated, and the second inlet end of the first control valve 310 and the outlet end of the first control valve 310 are communicated; the inlet end of the second control valve 330 and the first outlet end of the second control valve 330 are communicated, and the tail gas discharged from the gas outlet end of the catalytic unit 200 is returned to the gas inlet end of the catalytic unit 200 through the inlet end of the second control valve 330, the first outlet end of the second control valve 330, the inlet end of the control pump 320, the outlet end of the control pump 320, the second inlet end of the first control valve 310 and the outlet end of the first control valve 310.
[0049] When the coolant temperature is higher than or equal to the temperature preset value, the controller 400 controls the first inlet end of the first control valve 310 and the outlet end of the first control valve 310 to be communicated, and the second inlet end of the first control valve 310 and the outlet end of the first control valve 310 to be disconnected; the inlet end of the second control valve 330 and the first outlet end of the second control valve 330 are disconnected, so that all the tail gas of the gas outlet end of the catalytic unit 200 is discharged into the atmosphere.
[0050] It should be noted that when the engine 600 is in a cold start state, the inlet end of the second control valve 330 and the second outlet end of the second control valve 330 are connected, so that part of the tail gas discharged from the gas outlet end of the catalytic unit 200 is returned to the gas inlet end of the catalytic unit 200, and the remaining part of the tail gas is discharged to the atmosphere through the second outlet end of the second control valve 330.
[0051] In another embodiment of the utility model, the recovery unit 300 includes a recovery pipeline, a first control valve 310 and a second control valve 330, the inlet end of the recovery pipeline is connected to the gas outlet end of the catalytic unit 200, the outlet end of the recovery pipeline is connected to the gas inlet end of the catalytic unit 200, a control pump 320 is arranged on the recovery pipeline, the first control valve 310 is arranged at the outlet end of the recovery pipeline, and the second control valve 330 is arranged at the inlet end of the recovery pipeline.
[0052] For example, the control pump 320 adopts a gas pump, when the coolant temperature is too low and lower than the temperature preset value, the controller 400 controls the first control valve 310, the gas pump and the second control valve 330 to be opened, and the tail gas discharged from the gas outlet end of the catalytic unit 200 is returned to the gas inlet end of the catalytic unit 200 by the gas pump, so as to rapidly increase the catalyst temperature.
[0053] When the coolant temperature is higher than or equal to the temperature preset value, the controller 400 controls the first control valve 310, the gas pump and the second control valve 330 to be closed, and all the tail gas of the gas outlet end of the catalytic unit 200 is discharged into the atmosphere.
[0054] It should be noted that the control pump 320 is used to increase the flow rate and pressure of the gas; in other embodiments, the control pump 320 can be replaced with a variable diameter pipe, which is connected to the outlet end of the catalytic unit 200 as a recovery pipeline, the outlet end of the catalytic unit 200 is connected to the inlet end of the catalytic unit 200, the diameter of the variable diameter pipe gradually decreases from the inlet end to the outlet end, so as to increase the flow rate and pressure of the gas; the first control valve 310 is arranged at the outlet end of the variable diameter pipe; the second control valve 330 is arranged at the inlet end of the variable diameter pipe.
[0055] Optionally, the recovery pipeline comprises a first pipeline and a second pipeline, the first pipeline is connected between the control pump 320 and the inlet end of the catalytic unit 200, the second pipeline is connected between the control pump 320 and the outlet end of the catalytic unit 200, the first control valve 310 is arranged in the first pipeline, the first control valve 310 is an on-off valve, which realizes the on-off control of the first pipeline, and in the embodiment, the first pipeline specifically adopts a normally closed electric valve.
[0056] Further, the second control valve 330 is arranged in the second pipeline, and the second control valve 330 is a flow regulating valve, which can control the on-off of the second pipeline and adjust the opening degree of the valve, and in the embodiment, the second control valve 330 specifically adopts a normally closed electric valve.
[0057] It can be understood that when the cooling liquid temperature is too low and lower than the temperature preset value, the first control valve 310, the control pump 320 and the second control valve 330 are controlled to be opened, and the tail gas discharged from the outlet end of the catalytic unit 200 is flowed back to the catalytic unit 200 for combustion and temperature rise by the control pump 320, and with the increase of the cooling liquid temperature, the opening degree of the second control valve 330 is gradually reduced, and part of the exhaust gas enters the atmosphere. It should be noted that the second control valve 330 cannot be in a fully closed state, otherwise the tail gas can only circulate internally and cannot be discharged.
[0058] It should be noted that the first temperature sensor 100 can be used to monitor the cooling liquid temperature of the engine 600, and the opening degree of the second control valve 330 is controlled to realize the recovery of the tail gas during cold start and send the tail gas back to the inlet of the catalytic unit 200.
[0059] In an optional embodiment of the utility model, Figure 2 The structure schematic diagram two of the tail gas aftertreatment mechanism is illustrated, Figure 2As shown, the catalytic unit 200 comprises an oxidation catalyst 210 (DOC), a particulate filter 220 (DPF) and a catalytic reducer 230 (SCR) arranged in sequence along the airflow direction, the oxidation catalyst 210 is provided with a second temperature sensor 500, and the controller 400 is an electronic control unit (ECU), and the controller 400 is connected to the second temperature sensor 500.
[0060] It can be understood that the second temperature sensor 500 is used for monitoring the core temperature of the oxidation catalyst 210 (DOC), and the tail gas discharged from the gas outlet end of the catalytic unit 200 is returned to the DOC for combustion and temperature rise, accompanied by the increase of the cooling liquid temperature, the opening degree of the second control valve 330 is gradually reduced, and part of the exhaust gas enters the atmosphere; when the DOC core temperature monitored by the second temperature sensor 500 reaches the set temperature, the first control valve 310 and the second control valve 330 are closed, and all the tail gas at the gas outlet end of the catalytic unit 200 is discharged into the atmosphere.
[0061] Optionally, the inner wall of the channel of the particulate filter 220 is coated with a noble metal catalyst, and the coating amount of the noble metal catalyst is 1-10 mg / cm 3 The noble metal catalyst comprises at least one of Pt, Pd and Rh.
[0062] Preferably, the noble metal catalyst is a combination of Pt, Pd and Rh, and the content of Pt is 5-20 wt%, the content of Pd is 60-90 wt%, and the content of Rh is 5-20 wt% based on the noble metal catalyst.
[0063] It should be noted that the tail gas during the cold start of the engine can quickly increase the catalyst temperature under the cold start state, thereby reducing the content of the noble metal catalyst and reducing the cost.
[0064] In an embodiment of the utility model, the gas outlet end of the catalytic unit 200 is provided with a pressure sensor (not shown in the figure) connected with the controller 400.
[0065] It can be understood that the pressure sensor is used for detecting the pressure of the tail gas in the exhaust pipe line at the gas outlet end of the catalytic unit 200, the pressure sensor is electrically connected with the controller 400, the controller 400 can monitor the pressure fluctuation in the exhaust pipe line in real time through the signal input of the pressure sensor, and can control the working state of the first control valve 310 and the second control valve 330 to avoid the influence of the conduction of the recovery unit 300 on the normal exhaust of the engine 600 under the normal working condition of the engine 600.
[0066] The embodiment of the second aspect of the utility model provides an engine system, the engine system includes engine 600 and the tail gas post-processing mechanism provided by any of the above embodiments, and the air inlet end of the catalytic unit 200 is connected to the air outlet end of the engine 600.
[0067] The embodiment of the third aspect of the utility model provides a working machine, which comprises the engine system provided by any of the above embodiments.
[0068] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the utility model, and not to limit them; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the utility model.
Claims
1. An exhaust gas aftertreatment mechanism characterized by, include: A first temperature sensor is installed in the engine and is used to monitor the coolant temperature of the engine. A catalytic converter, wherein the intake end of the catalytic converter is connected to the exhaust end of the engine; A recovery unit, wherein the outlet of the recovery unit is connected to the inlet of the catalytic unit, and the inlet of the recovery unit is connected to the outlet of the catalytic unit; A controller, connected to the first temperature sensor, is configured to control the inlet and outlet of the recovery unit to open when the coolant temperature is lower than a preset temperature value, so that at least part of the exhaust gas from the outlet of the catalytic unit flows back to the inlet of the catalytic unit through the recovery unit, and to control the inlet and outlet of the recovery unit to close when the coolant temperature is higher than or equal to the preset temperature value, so that all the exhaust gas from the outlet of the catalytic unit is discharged into the atmosphere.
2. The exhaust gas aftertreatment mechanism of claim 1, wherein, The recycling unit includes: A first control valve, the first inlet end of which is connected to the exhaust end of the engine, and the outlet end of which is connected to the intake end of the catalytic converter. A control pump, the outlet end of which is connected to the second inlet end of the first control valve; The second control valve has its inlet end connected to the outlet end of the catalytic unit, its first outlet end connected to the inlet end of the control pump, and its second outlet end connected to the atmosphere. The controller is connected to the first control valve, the control pump, and the second control valve.
3. The exhaust gas aftertreatment mechanism of claim 1, wherein, The recycling unit includes components connected to: A variable diameter pipe, wherein the inlet end of the variable diameter pipe is connected to the outlet end of the catalytic unit, and the outlet end of the variable diameter pipe is connected to the inlet end of the catalytic unit, and the diameter of the variable diameter pipe gradually decreases from the inlet end to the outlet end. The first control valve is located at the outlet end of the reducing pipe; The second control valve is located at the inlet end of the reducing pipe.
4. The exhaust gas aftertreatment mechanism according to claim 2 or 3, characterized in that The first control valve is a switching valve, and the second control valve is a flow regulating valve.
5. The exhaust gas aftertreatment mechanism according to any one of claims 1 to 3, characterized in that The catalytic unit includes an oxidation catalyst, a particulate trap, and a catalytic reducer arranged sequentially along the gas flow direction.
6. The exhaust gas aftertreatment mechanism of claim 5, wherein, It also includes a second temperature sensor disposed on the oxidation catalyst, and the controller is connected to the second temperature sensor.
7. The exhaust gas aftertreatment mechanism of claim 5, wherein, The gas outlet of the catalytic unit is equipped with a pressure sensor connected to the controller.
8. The exhaust gas aftertreatment mechanism of claim 5, wherein, The inner wall of the pores of the particulate trap is coated with a noble metal catalyst, which includes at least one of Pt, Pd and Rh.
9. An engine system characterized by, The system includes an engine and an exhaust aftertreatment mechanism as described in any one of claims 1 to 8, wherein the intake end of the catalytic unit is connected to the exhaust end of the engine.
10. A work machine characterized by, Includes the engine system as described in claim 9.