Carbon canister desorption system and desorption method, and fuel tank system leak detection method

Abstract

A carbon canister desorption system, comprising: a carbon canister (3), a fuel tank (4), a turbocharger (14), and an air inlet pipe (11). The carbon canister is provided with a first air inlet, a second air inlet, and a first air outlet, wherein the first air inlet is connected to the fuel tank (4), the second air inlet is connected to a first air branch pipe, the first air outlet is connected to a second air branch pipe, and the second air branch pipe is used for delivering the gas in the carbon canister (3) to a first end of the air inlet pipe. The turbocharger (14) is used for compressing air and then flowing the air to the carbon canister (3) through the first air branch pipe, and desorbing the carbon canister (3). Air is compressed by the turbocharger and then flows to the carbon canister through the first air branch pipe so as to desorb the carbon canister, and desorbed gas flows to the air inlet pipe through the second air branch pipe, so that the desorption pressure of the carbon canister is precisely controlled, and a good carbon canister desorption effect is achieved. The present invention can be widely applied to the technical field of engines. The present invention further relates to a desorption method and a fuel tank system leak detection method.

Description

A carbon canister desorption system, desorption method, and fuel tank system leak detection method Technical Field

[0001] The present application relates to the field of engine technology, and in particular to a carbon canister desorption system, a desorption method, and a fuel tank system leakage detection method. Background Art

[0002] Today, cars are the most convenient and practical means of transportation and are indispensable in our daily lives. The application of new energy technologies is further advancing the development of intelligent and electrified vehicles. Due to the volatility of fuel, the oil in the fuel tank can easily evaporate into the atmosphere during refueling, driving, or due to increased ambient temperature, causing pollution. Existing cars generally use activated carbon canisters to absorb fuel vapor during operation. The carbon particles inside the canister have a limited ability to adsorb fuel. To ensure the effectiveness of fuel adsorption and avoid "breakdown" of the canister due to excessive fuel adsorption, the adsorbed fuel inside the canister must be regularly desorbed.

[0003] In existing carbon canister desorption, the desorption pressure is established by using the difference between atmospheric pressure and the negative pressure of the intake pipe. Therefore, the desorption pressure is limited and difficult to accurately control, resulting in poor carbon canister desorption effect.

[0004] Summary of the Invention

[0005] In view of this, the purpose of the embodiments of the present application is to provide a carbon canister desorption system, a desorption method and a fuel tank system leakage detection method, which can accurately control the desorption pressure of the carbon canister and have a good carbon canister desorption effect.

[0006] In a first aspect, an embodiment of the present application provides a carbon canister desorption system, comprising: a carbon canister, a fuel tank, a turbocharger, and an intake pipe;

[0007] The carbon canister is provided with a first air inlet, a second air inlet, and a first air outlet, wherein the first air inlet is connected to the fuel tank, the second air inlet is connected to a first bronchial pipe, and the first air outlet is connected to a second bronchial pipe, and the second bronchial pipe is used to transport the gas in the carbon canister to the first end of the air inlet pipe or the second end of the turbocharger;

[0008] The turbocharger is used to compress the air and flow it to the carbon canister through the first duct, and to desorb the carbon canister.

[0009] Optionally, a main air pipe is arranged between the first end of the turbocharger and the first end of the intake pipe, a throttle valve is provided on the main air pipe, the second end of the intake pipe is connected to the engine, the intake pipe is used to transport the gas from the first end of the intake pipe to the engine, and the first branch pipe is connected to the main air pipe at the first end of the turbocharger.

[0010] Optionally, the first bronchial pipe, the carbon canister and the second bronchial pipe form a desorption pipeline, and the desorption pipeline is provided with a carbon canister valve, a multi-way valve and a valve group.

[0011] Optionally, an intercooler is provided on the main air pipe, and the first branch pipe is connected to the first end, the second end or the intercooler of the intercooler.

[0012] Optionally, the second bronchus is connected to the first end of the air inlet pipe.

[0013] Optionally, the second bronchial pipe is communicated with the second end of the turbocharger.

[0014] Optionally, the first branch of the desorption pipeline includes a first branch, a second branch, a third branch and a regulating valve, the first end of the third branch is connected to the second air inlet, the second end of the third branch is connected to the first end of the second branch and the first end of the first branch respectively, the second end of the first branch is connected to the first end of the intercooler, the second end of the second branch is connected to the second end of the intercooler, and the regulating valve is located at the intersection of the first branch, the second branch and the third branch, and the regulating valve is used to adjust the ratio of the third branch connected to the first branch and the second branch.

[0015] Optionally, a pressure stabilizing chamber and a flow limiting valve are provided on the desorption pipeline.

[0016] The implementation of the embodiments of the present application has the following beneficial effects: The embodiments of the present application provide a carbon canister desorption system, comprising: a carbon canister, a fuel tank, a turbocharger, and an intake pipe; the carbon canister is provided with a first air inlet, a second air inlet, and a first air outlet, the first air inlet being connected to the fuel tank, the second air inlet being connected to a first bronchial pipe, the first air outlet being connected to a second bronchial pipe, the second bronchial pipe being used to transport the gas in the carbon canister to the first end of the intake pipe or the second end of the turbocharger; the turbocharger is used to compress the air and flow it to the carbon canister through the first bronchial pipe, thereby desorbing the carbon canister. The turbocharger compresses the air and flows it to the carbon canister through the first bronchial pipe, thereby desorbing the carbon canister, and the desorbed gas flows to the intake pipe through the second bronchial pipe, thereby precisely controlling the desorption pressure of the carbon canister and achieving a good desorption effect on the carbon canister.

[0017] In a second aspect, an embodiment of the present application provides a carbon canister desorption method, which is applied to the above-mentioned carbon canister desorption system. The carbon canister desorption method includes:

[0018] When it is detected that the engine is in a first preset working state, closing the vent valve and switching the multi-way valve so that the first branch pipe is connected to the carbon canister;

[0019] adjusting a pressure difference between a first end and a second end of the throttle valve through the turbocharger and the throttle valve;

[0020] delivering the gas from the first end of the turbocharger to the carbon canister through the first duct, so that the gas is desorbed from the carbon canister;

[0021] The desorbed gas is delivered to the first end of the intake pipe through the second branch pipe, and the desorbed gas is delivered to the engine through the second end of the intake pipe.

[0022] In a third aspect, an embodiment of the present application provides a carbon canister desorption method, which is applied to the above-mentioned carbon canister desorption system. The carbon canister desorption method includes:

[0023] When it is detected that the engine is in a second preset working state, closing the vent valve and switching the multi-way valve to connect the first branch pipe to the carbon canister;

[0024] adjusting the pressure at the first end of the throttle valve through the turbocharger and the throttle valve;

[0025] delivering the gas from the first end of the turbocharger to the carbon canister through the first duct, so that the gas is desorbed from the carbon canister;

[0026] The second branch pipe delivers the desorbed gas to the second end of the turbocharger, so that the turbocharger delivers the desorbed gas to the intake pipe through the main air pipe, and then delivers the desorbed gas to the engine through the intake pipe.

[0027] Optionally, the method further includes:

[0028] When it is detected that the engine is in a third preset operating state, closing the vent valve and switching the multi-way valve to connect the first branch pipe to the carbon canister;

[0029] regulating the pressure at a first end of the turbocharger via the turbocharger and the throttle valve;

[0030] The regulating valve is used to adjust the gas ratio at the first end or the second end of the intercooler so as to adjust the temperature of the desorbed gas. The desorbed gas flows into the desorption pipeline and enters the carbon canister to desorb the carbon canister.

[0031] In a fourth aspect, an embodiment of the present application provides a fuel tank system leakage detection method, which is applied to the above-mentioned carbon canister purge system. The fuel tank system leakage detection method includes:

[0032] By adjusting the opening and closing combination to the first combination, the fuel tank system forms a relatively closed space;

[0033] By adjusting the opening and closing combination, the turbocharger compresses the gas and transmits it to the fuel tank through the first bronchial pipe, so that the pressure of the fuel tank system increases;

[0034] Obtaining a pressure rise curve of the fuel tank system;

[0035] Obtaining a first comparison result according to the pressure rise curve and a preset rise curve;

[0036] When the pressure of the oil tank system reaches a set value, adjusting the opening and closing combination to a second combination;

[0037] Obtaining a pressure change curve of the fuel tank system;

[0038] Obtaining a second comparison result according to the pressure change curve and a preset change curve;

[0039] Adjusting the opening and closing combination to a third combination;

[0040] obtaining a pressure drop curve of the fuel tank system;

[0041] Obtaining a third comparison result according to the pressure drop curve and a preset drop curve;

[0042] Fuel tank system leakage alarm information is generated according to the first comparison result, the second comparison result and / or the third comparison result.

[0043] The implementation of the embodiments of the present application includes the following beneficial effects: The embodiments of the present application provide a method for detecting leakage of a fuel tank system, which increases the pressure of the fuel tank system through a turbocharger and detects the pressure rise curve of the fuel tank. After comparing the pressure rise curve with the preset rise curve, it is possible to quickly determine whether the carbon canister valve is closed normally. After closing the multi-way valve, the pressure change curve of the fuel tank system is detected, so that it is possible to quickly determine whether the multi-way valve is closed normally based on the pressure change curve and the preset change curve. After the multi-way valve is connected to the vent valve, the pressure drop curve of the fuel tank system is detected. Based on the pressure drop curve and the preset drop curve, it is possible to quickly determine whether the vent valve is leaking. The fuel tank system leakage detection can also be performed when the engine is working, and the detection frequency is high and the detection results are accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] FIG1 is a schematic structural diagram of a carbon canister desorption system provided in an embodiment of the present application;

[0045] FIG2 is a schematic structural diagram of another carbon canister desorption system provided in an embodiment of the present application;

[0046] FIG3 is a schematic structural diagram of another carbon canister desorption system provided in an embodiment of the present application;

[0047] FIG4 is a schematic structural diagram of another carbon canister desorption system provided in an embodiment of the present application;

[0048] FIG5 is a flowchart of a carbon canister desorption method provided in an embodiment of the present application;

[0049] FIG6 is a flowchart of another carbon canister desorption method provided in an embodiment of the present application;

[0050] FIG7 is a flowchart of the steps of a fuel tank system leakage detection method provided in an embodiment of the present application.

[0051] Figure numerals: vent valve 1, multi-way valve 2, carbon canister 3, fuel tank 4, carbon canister valve 5, first valve body 6, pressure stabilizing chamber 7, second valve body 8, throttle valve 9, regulating valve 10, intake pipe 11, engine 12, exhaust pipe 13, turbocharger 14, air filter 15, intercooler 16, flow limiting valve 17. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0053] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0054] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of this application, unless otherwise specified, "plurality" means two or more.

[0055] In the first aspect, referring to FIG1 , an embodiment of the present application provides a carbon canister desorption system, comprising: a carbon canister 3 , a fuel tank 4 , a turbocharger 14 and an intake pipe 11 ;

[0056] The carbon canister 3 is provided with a first air inlet, a second air inlet, and a first air outlet. The first air inlet is connected to the fuel tank 4, the second air inlet is connected to a first bronchial pipe, and the first air outlet is connected to a second bronchial pipe. The second bronchial pipe is used to transport the gas in the carbon canister 3 to the first end of the intake pipe 11 or the second end of the turbocharger 14;

[0057] The turbocharger 14 is used to compress the air and flow it to the carbon canister 3 through the first duct, and to desorb the carbon canister 3 .

[0058] Specifically, referring to Figure 1 , the canister desorption system primarily comprises a canister 3, a fuel tank 4, a turbocharger 14, and an intake pipe 11. The canister 3 is provided with a first air inlet, a second air inlet, and a first air outlet. The canister 3 is connected to the fuel tank 4 via the first air inlet. Oil vapor from the fuel tank 4 enters the first air inlet of the canister 3 through a pipeline, and then enters the canister 3, where it is adsorbed by the activated carbon within the canister 3. The second air inlet of the canister 3 is connected to the first end of the turbocharger 14 via a first duct. The turbocharger 14 compresses air and delivers it to the canister 3 via the first duct. The delivered gas desorbs the canister 3. The first air outlet of the canister 3 is connected to the first end of the intake pipe 11 via a second duct. The gas within the canister 3 is delivered to the first end of the intake pipe 11 via the second duct, thereby delivering the desorbed gas to the intake pipe 11 and, in turn, to the engine for combustion. The turbocharger 14 is used as a device for establishing a pressure difference of the desorption flow gas of the carbon canister 3 , and the pressure difference can be controlled by the operating conditions of the engine 12 so that the evaporated fuel inside the carbon canister 3 can be fully desorbed.

[0059] In some optional embodiments, referring to Figures 1-2, a main air pipe is arranged between the first end of the turbocharger 14 and the first end of the intake pipe 11, a throttle valve 9 is provided on the main air pipe, and the second end of the intake pipe 11 is connected to the engine 12, and the intake pipe 11 is used to transport the gas at the first end of the intake pipe 11 to the engine 12.

[0060] Specifically, the first end of the turbocharger 14 is connected to the first end of the intake pipe 11 via a main air pipe. A throttle valve 9 is provided on the main air pipe. During canister desorption, the air pressure at the first end (upstream) of the throttle valve 9 is greater than the air pressure at the second end (downstream) of the throttle valve 9. The throttle valve 9 controls the gas flow rate, thereby controlling the gas flow entering the intake pipe 11. The second end of the intake pipe 11 is connected to the engine 12, and the intake pipe 11 delivers the desorbed gas to the engine 12 for combustion.

[0061] In some optional embodiments, referring to FIG. 1 , a carbon canister valve 5 is provided on the second bronchus, a first end of the carbon canister valve 5 is communicated with the first air outlet, and a second end of the carbon canister valve 5 is communicated with the second end of the throttle valve 9 .

[0062] In some optional embodiments, the first end of the carbon canister valve 5 is communicated with the first end of the intake pipe 11 and the second end of the throttle valve 9 respectively.

[0063] Specifically, referring to Figure 1 , the second branch pipe is provided with a canister valve 5 . When canister valve 5 is opened, the gas in canister 3 flows toward the second (downstream) end of throttle valve 9 , thereby entering intake pipe 11 and flowing into the engine for combustion. The gas in canister 3 can flow into intake pipe 11 because the pressure at the first end of throttle valve 9 is greater than the pressure at the second end.

[0064] In some optional embodiments, referring to FIG. 2 , a carbon canister valve 5 is provided on the second bronchus, a first end of the carbon canister valve 5 is communicated with the first air outlet, and a second end of the carbon canister valve 5 is communicated with the second end of the turbocharger 14 .

[0065] In some optional embodiments, a first valve body 6 is provided on the pipeline from the carbon canister 3 to the fuel tank 4. This first valve body 6 controls the flow of gas into and out of the fuel tank 4. If the pressure of the gas blown into the carbon canister 3 is too high, the first valve body 6 closes to protect the fuel tank 4. Alternatively, if the fuel tank pressure is too high and the pressure in the carbon canister 3 is lower than that in the fuel tank 4, the first valve body 6 opens to relieve the pressure in the fuel tank 4. It should be noted that the first valve body 6 can be an on-off valve, a solenoid valve, or an intelligent regulating valve, without limitation herein.

[0066] In some optional embodiments, the first end of the first valve body 6 is communicated with the first air outlet, the second end of the first valve body 6 is communicated with the first end of the carbon canister valve, and the second end of the carbon canister valve is communicated with the second end of the turbocharger.

[0067] Specifically, referring to Figures 3-4, the second bronchial pipe has a second end of the turbocharger 14 where the gas in the carbon canister 3 flows after the carbon canister valve 5 is opened, thereby increasing or reducing the power of the turbocharger 14 according to the gas flow rate; the second end of the turbocharger 14 is also connected to an air filter 15, and the turbocharger 14 delivers the gas flowing out of the carbon canister 3 at the second end and the atmosphere flowing into the air filter 15 to the throttle valve 9, and then delivers it to the intake pipe 11 and the engine 12.

[0068] In some optional embodiments, an intercooler 16 is provided on the main air pipe from the first end of the throttle 9 to the first end of the turbocharger 14 , and the first branch pipe is connected to the first end or the second end of the intercooler 16 , or is connected to the intercooler 16 .

[0069] 3-4 , the first bronchial pipe is connected to a first end of the intercooler 16 , or a second end of the intercooler 16 , or is directly connected to a connection end point on the intercooler 16 .

[0070] In some optional embodiments, the first bronchial pipe includes a first branch, a second branch and a third branch, the first end of the third branch is connected to the second air inlet, the second end of the third branch is respectively connected to the first end of the second branch and the first end of the first branch, the second end of the first branch is connected to the first end of the intercooler, and the second end of the second branch is connected to the second end of the intercooler.

[0071] In some optional embodiments, a regulating valve 10 is provided on the first bronchus. The regulating valve 10 is located at the intersection of the first branch, the second branch and the third branch. The regulating valve 10 is used to regulate the third branch to connect with the first branch or the second branch.

[0072] Specifically, referring to Figures 3-4 , the intercooler 16 is capable of regulating the temperature of the gas flowing to the engine 12. A regulating valve 10 is provided on the first branch pipe. This valve 10 regulates whether the third branch pipe connects to the first end (inlet end) or the second end (outlet end) of the intercooler 16. When the gas desorbed from the carbon canister 3 requires higher-temperature gas for desorption, the regulating valve 10 adjusts the third branch pipe to connect to the first end (inlet end) of the intercooler 16. When the gas flowing into the carbon canister 3 requires lower-temperature gas, the regulating valve 10 adjusts the third branch pipe to connect to the second end (outlet end) of the intercooler 16. For example, when the gas flows into the fuel tank 4, the regulating valve 10 adjusts the third branch pipe to connect to the second end of the intercooler 16. The turbocharger 14 delivers both the ambient air and the desorbed gas to the engine. The gas is then delivered to the carbon canister for desorption via the third branch pipe, which has a smaller cross-sectional area, thereby simultaneously meeting both the engine's intake requirements and the canister's desorption requirements.

[0073] In some optional embodiments, a multi-way switching unit, a pressure stabilizing chamber 7 and a flow limiting valve 17 are provided on the third branch pipe, the first end of the multi-way switching unit is connected to the second air inlet, the second end of the multi-way switching unit is connected to the first end of the pressure stabilizing chamber 7, the second end of the pressure stabilizing chamber 7 is connected to the first end of the flow limiting valve 17, and the second end of the flow limiting valve 17 is connected to the regulating valve 10.

[0074] In some optional embodiments, a second valve body 8 is further provided on the third branch pipe, and the second valve body 8 is connected to the multi-way switching unit or the flow limiting valve 17.

[0075] Specifically, the valve assembly includes a first valve body 6 and a second valve body 8. A flow-limiting valve 17 limits the flow of gas from the main pipe to prevent excessive airflow. The gas then passes through the second valve body 8 for check, is stabilized by the pressure-stabilizing chamber 7, and then is delivered to the carbon canister 3 via the multi-way switching unit, thereby desorbing the carbon canister 3. The second valve body 8 and the first valve body 6 can be on-off valves, solenoid valves, or intelligent regulating valves, without limitation.

[0076] In some optional embodiments, the third end of the multi-channel switching unit is used to connect to the outside atmosphere.

[0077] Specifically, the multi-channel switching unit has both a multi-channel switching function and a ventilation function. The third end of the multi-channel switching unit has a ventilation function for connecting to the outside atmosphere.

[0078] In some optional embodiments, the multi-way switching unit includes a multi-way valve 2 and a vent valve 1, the first end of the multi-way valve 2 is connected to the second air inlet, the second end of the multi-way valve 2 is connected to the first end of the pressure stabilizing chamber 7, and the third end of the multi-way valve 2 is connected to the vent valve 1, and the vent valve 1 is used to connect to the outside atmosphere.

[0079] Specifically, the multi-way valve 2 can be a three-way switching valve, allowing connection between any two or all three ends. The pressure-stabilizing chamber 7 stabilizes the pressure of the gas flowing into the carbon canister 3, while the second valve body 8 controls the flow of air compressed by the turbocharger 14 to the carbon canister 3. The diameters of the first and second branches of the first branch pipe are smaller than the diameter of the main air pipe, allowing most of the air compressed by the turbocharger 14 to flow into the engine 12.

[0080] In some optional embodiments, the third end of the multi-way valve 2 is connected to a vent valve 1, and the vent valve 1 is used to connect to the outside atmosphere.

[0081] In some optional embodiments, the vehicle's fuel tank 4 is connected to the carbon canister 3, which collects fuel vapor generated by the vehicle's fuel tank 4 and desorbs it after it is full. The carbon canister 3 is vented to the atmosphere via a multi-way valve 2 and a vent valve 1. The multi-way valve 2 can connect any two or all of the pipelines. The desorbed gas departs from the carbon canister 3, passes through the carbon canister valve 5, and enters the intake pipe 11 downstream of the throttle 9.

[0082] In some optional embodiments, referring to Figure 1, the external environmental pressure is greater than the pressure of the intake pipe 11 downstream of the throttle 9 of the engine 12, and the external environmental air passes through the vent valve 1→multi-way valve 2→carbon canister 3→carbon canister valve 5→the first end of the intake pipe 11 downstream of the throttle 9. When the external air passes through the carbon canister 3, it carries the fuel vapor absorbed inside it and enters the engine 12 through the intake pipe 11 for combustion, completing the desorption operation of the carbon canister 3.

[0083] When the ambient pressure is lower than the pressure in intake pipe 11 downstream of engine 12's throttle valve 9, vent valve 1 closes, multi-way valve 2 connects pressure-stabilizing chamber 7 and carbon canister 3, and turbocharger 14 dynamically adjusts the intake pressure in intake pipe 11. Simultaneously, throttle valve 9 is adjusted to create a pressure differential upstream and downstream of throttle valve 9. The higher-pressure intake air flows through intercooler 16 and second valve body 8, forming a purge route: intercooler 16 → flow limiting valve 17 → second valve body 8 → pressure-stabilizing chamber 7 → multi-way valve 2 → carbon canister 3 → carbon canister valve 5 → downstream of throttle valve 9. Fuel vapor, after purging carbon canister 3 via this route, enters engine 12 through intake pipe 11 for combustion. The combusted gases from engine 12 are discharged through exhaust pipe 13.

[0084] In some optional embodiments, referring to FIG2 , a vehicle fuel tank 4 is connected to a carbon canister 3. The carbon canister 3 collects fuel vapor generated by the vehicle fuel tank 4 and detects it via a pressure sensor. Desorption occurs when the carbon canister 3 is full. The carbon canister 3 is vented to the atmosphere via a multi-way valve 2 and a vent valve 1. The desorbed gas originates from the carbon canister 3, passes through the carbon canister valve 5, and then enters the pipeline at the second end of the turbocharger 14. A first valve body 6 controls the flow of gas from the carbon canister valve 5 to the fuel tank 4. The first valve body 6 closes promptly when the pressure is too high to prevent damage to the fuel tank.

[0085] In some optional embodiments, referring to FIG. 2 , when engine 12 is in a low-load state, the ambient pressure is greater than the pressure in intake pipe 11 downstream of throttle valve 9 of engine 12. Ambient air flows through vent valve 1 → multi-way valve 2 → carbon canister 3 → carbon canister valve 5 → turbocharger 14 → intercooler 16 → intake pipe 11 downstream of throttle valve 9. As this air passes through carbon canister 3, it carries along the fuel vapor absorbed within it, which then enters engine 12 through intake pipe 11 for combustion, completing the desorption process of carbon canister 3.

[0086] When engine 12 is under high load, the ambient pressure is lower than the pressure in intake manifold 11 downstream of engine 12's throttle valve 9. At this point, vent valve 1 is closed, and multi-way valve 2 connects pressure-stabilizing chamber 7 and carbon canister 3. The turbocharger 14 dynamically adjusts the intake pressure in intake manifold 11, adjusting throttle valve 9 to create a pressure differential upstream and downstream of throttle valve 9. The high-pressure inlet is formed by intercooler 16 through second valve body 8. At this point, gas flows as follows: intercooler 16 → flow-limiting valve 17 → second valve body 8 → pressure-stabilizing chamber 7 → multi-way valve 2 → carbon canister 3 → carbon canister valve 5 → turbocharger 14 → intercooler 16 → intake manifold 11 downstream of throttle valve 9. Fuel vapor, after purging carbon canister 3, travels through this route from intake manifold 11 to engine 12 for combustion.

[0087] The implementation of the embodiments of the present application has the following beneficial effects: The embodiments of the present application provide a carbon canister desorption system, comprising: a carbon canister 3, a fuel tank 4, a turbocharger 14, and an intake pipe 11; the carbon canister 3 is provided with a first air inlet, a second air inlet, and a first air outlet, the first air inlet being connected to the fuel tank 4, the second air inlet being connected to the first end of the turbocharger 14 via a first bronchial pipe, and the first air outlet being connected to the first end of the intake pipe 11 via a second bronchial pipe; the turbocharger 14 is configured to compress air and flow it to the carbon canister 3 through the first bronchial pipe, thereby desorbing the carbon canister. The desorbed gas flows to the intake pipe via the second bronchial pipe, thereby precisely controlling the desorption pressure of the carbon canister and achieving a good desorption effect. Without adding other vehicle components, the turbocharger is used to establish the pressure differential for the canister desorption flow. This pressure differential can be controlled based on the engine operating conditions, ensuring sufficient desorption of the evaporated fuel within the canister. This eliminates the limitation of using atmospheric pressure to establish a pressure differential during the desorption process and enhances the controllability of the desorption process. Control strategies can be used to achieve desorption under different operating conditions, making it suitable for conventional, hybrid, and plug-in hybrid vehicles.

[0088] Referring to Figure 5, in the second aspect, the embodiment of the present application provides a carbon canister desorption method, which is applied to a carbon canister desorption system. Referring to Figure 1, the carbon canister desorption system includes a carbon canister 3, a fuel tank 4, a turbocharger 14 and an intake pipe 11; the carbon canister 3 is provided with a first air inlet, a second air inlet and a first air outlet, the first air inlet is connected to the fuel tank 4, the second air inlet is connected to a first bronchial pipe, the first air outlet is connected to a second bronchial pipe, and a carbon canister valve 5 is provided on the second bronchial pipe, and the carbon canister valve 5 is used to adjust the opening and closing of the carbon canister. The air flow in the second bronchial pipe is adjusted by adjusting the degree of the air flow in the second bronchial pipe. A multi-way valve 2 is provided between the first bronchial pipe and the second air inlet. The multi-way valve 2 is connected to a vent valve 1. The vent valve 1 is used to connect to the outside atmosphere. A turbocharger 14 is used to compress the air and flow it to the carbon canister 3 through the first bronchial pipe, and desorb the carbon canister 3. A throttle valve 9 is connected to the main air pipe from the first end of the turbocharger 14 to the first end of the intake pipe 11. The second end of the intake pipe 11 is connected to the engine 12. The carbon canister desorption method includes:

[0089] S501: When it is detected that the engine is in a first preset operating state, the vent valve is closed and the multi-way valve is switched to connect the first bronchial pipe to the carbon canister;

[0090] S502, adjusting the pressure difference between the first end and the second end of the throttle valve through the turbocharger and the throttle valve;

[0091] S503, delivering the gas from the first end of the turbocharger to the carbon canister through the first bronchial pipe, so that the gas is desorbed from the carbon canister;

[0092] S504: delivering the desorbed gas to the first end of the intake pipe through the second bronchial pipe, and delivering the desorbed gas to the engine through the second end of the intake pipe.

[0093] In some optional embodiments, the main air pipe at the first end of the throttle is connected to an intercooler 16, the first branch pipe includes a regulating valve 10, a first branch pipe, a second branch pipe and a third branch pipe, the first end of the third branch pipe is connected to the second air inlet, the second end of the third branch pipe is connected to the first end of the second branch pipe and the first end of the first branch pipe respectively, the second end of the first branch pipe is connected to the first end of the intercooler 16, and the second end of the second branch pipe is connected to the second end of the intercooler 16. A carbon canister valve 5, a multi-way valve 2 and a valve group are provided on the desorption pipeline. The method also includes: when it is detected that the engine is in a third preset working state, closing the vent valve 1, switching the multi-way valve 2 to connect the first branch pipe to the carbon canister 3; adjusting the pressure of the first end of the turbocharger 14 by the turbocharger 14 and the throttle 9; adjusting the gas ratio at the first end or the second end of the intercooler 16 by the regulating valve 10 to adjust the temperature of the desorbed gas, and the desorbed gas flows into the desorption pipeline, enters the carbon canister 3, and desorbs the carbon canister 3.

[0094] It can be seen that the contents of the above-mentioned carbon canister desorption system embodiment are all applicable to the present carbon canister desorption method embodiment. The functions specifically implemented by the present carbon canister desorption method embodiment are the same as those of the above-mentioned carbon canister desorption system embodiment, and the beneficial effects achieved are also the same as those achieved by the above-mentioned carbon canister desorption system embodiment.

[0095] Referring to Figure 6, in the third aspect, the embodiment of the present application provides a carbon canister desorption method, which is applied to a carbon canister desorption system. Referring to Figure 2, the carbon canister desorption system includes a carbon canister 3, a fuel tank 4, a turbocharger 14 and an intake pipe 11; the carbon canister 3 is provided with a first air inlet, a second air inlet and a first air outlet, the first air inlet is connected to the fuel tank 4, the second air inlet is connected to a first bronchus, the first air outlet is connected to a second bronchus, and a carbon canister valve 5 is provided on the second bronchus, and the carbon canister valve 5 is used to adjust the air in the second bronchus by adjusting the opening. A multi-way valve 2 is provided between the first bronchial pipe and the second air inlet, and the multi-way valve 2 is connected to a vent valve 1, which is used to connect to the outside atmosphere; a turbocharger 14 is used to compress the air and flow it to the carbon canister 3 through the first bronchial pipe, and desorb the carbon canister 3. The desorbed gas enters the second end of the turbocharger 14. A throttle valve 9 is provided on the main air pipe from the first end of the turbocharger 14 to the first end of the intake pipe 11. The second end of the intake pipe 11 is connected to the engine 12. The carbon canister desorption method includes:

[0096] S601: When it is detected that the engine is in a second preset operating state, the vent valve is closed and the multi-way valve is switched to connect the first branch pipe to the carbon canister;

[0097] S602, adjusting the pressure at the first end of the throttle valve through the turbocharger and the throttle valve;

[0098] S603, delivering the gas from the first end of the turbocharger to the carbon canister through the first bronchial pipe, so that the gas is desorbed from the carbon canister;

[0099] S604: The second bronchial pipe delivers the desorbed gas to the second end of the turbocharger, so that the turbocharger delivers the desorbed gas to the intake pipe through the main air pipe, and then delivers the desorbed gas to the engine through the intake pipe.

[0100] Specifically, when it is detected that the engine is in the second preset working state, the vent valve is closed and the multi-way valve is switched to connect the pressure stabilizing chamber to the carbon canister; the pressure difference between the first end and the second end of the throttle is adjusted by the turbocharger and the throttle; the gas at the first end of the throttle is transported to the carbon canister through the first bronchial pipe to desorb the gas from the carbon canister; the second bronchial pipe transports the desorbed gas to the second end of the turbocharger, and the turbocharger transports the desorbed gas to the intake pipe through the main air pipe, and then transports it to the engine through the intake pipe.

[0101] It should be noted that the first preset working state, the second preset working state and the third preset working state may be the same or different, and are not specifically limited.

[0102] 3-4, in some optional embodiments, the main air pipe at the first end of the throttle is connected to the intercooler 16, the first branch pipe includes a regulating valve 10, a first branch pipe, a second branch pipe and a third branch pipe, the first end of the third branch pipe is connected to the second air inlet, the second end of the third branch pipe is connected to the first end of the second branch pipe and the first end of the first branch pipe respectively, the second end of the first branch pipe is connected to the first end of the intercooler 16, the second end of the second branch pipe is connected to the second end of the intercooler 16, the carbon canister valve 5, the multi-way valve 2 and the valve group are provided on the desorption pipeline, and the method further includes: when it is detected that the engine is in the third In the preset working state, the vent valve 1 is closed and the multi-way valve 2 is switched to connect the first branch pipe to the carbon canister 3; the pressure of the first end of the turbocharger 14 is adjusted by the turbocharger 14 and the throttle 9; the gas ratio at the first end or the second end of the intercooler 16 is adjusted by the regulating valve 10 to adjust the temperature of the desorbed gas, and the desorbed gas flows into the desorption pipeline and enters the carbon canister 3 to desorb the carbon canister 3; the carbon canister valve 5 transports the desorbed gas to the second end of the turbocharger 14, and the turbocharger 14 transports the desorbed gas to the intake pipe 11 through the main air pipe, and then transports it to the engine 12 through the intake pipe 11.

[0103] It can be seen that the contents of the above-mentioned carbon canister desorption system embodiment are all applicable to the present carbon canister desorption method embodiment. The functions specifically implemented by the present carbon canister desorption method embodiment are the same as those of the above-mentioned carbon canister desorption system embodiment, and the beneficial effects achieved are also the same as those achieved by the above-mentioned carbon canister desorption system embodiment.

[0104] Referring to Figure 7, in the fourth aspect, an embodiment of the present application provides a method for detecting leakage of a fuel tank system, and a carbon canister desorption system is applied. Referring to Figures 1-2, the carbon canister desorption system includes a carbon canister 3, a fuel tank 4, a turbocharger 14 and an intake pipe 11; the carbon canister 3 is provided with a first air inlet, a second air inlet and a first air outlet, the first air inlet is connected to the fuel tank 4, the second air inlet is connected to a first bronchial pipe, the first air outlet is connected to a second bronchial pipe, and the second bronchial pipe is used to transport the gas in the carbon canister 3 to the first end or the turbocharger of the intake pipe 11. The second end of the turbocharger 14; the turbocharger 14 is used to compress the air and flow it to the fuel tank 4 and the desorption pipeline through the first bronchus; a multi-way valve 2 is provided between the first bronchus and the second air inlet, and the multi-way valve 2 is connected to the vent valve 1, which is used to connect to the outside atmosphere. The carbon canister desorption system is provided with a pressure stabilizing chamber 7, a carbon canister valve 5 and a valve group. The vent valve 1, the multi-way valve 2, the valve group and the carbon canister valve 5 form an opening and closing combination. The fuel tank 4, the desorption pipeline and the opening and closing combination constitute the fuel tank system. The fuel tank system leakage detection method includes:

[0105] S701, adjusting the opening and closing combination to the first combination to form a relatively closed space for the fuel tank system;

[0106] S702, adjusting the opening and closing combination to cause the turbocharger to compress the gas and then deliver it to the fuel tank through the first bronchial pipe, thereby increasing the pressure of the fuel tank system;

[0107] S703, obtaining a pressure rise curve of the fuel tank system;

[0108] S704, obtaining a first comparison result based on the pressure rise curve and the preset rise curve;

[0109] S705, when the pressure of the fuel tank system reaches the set value, adjusting the opening and closing combination to the second combination;

[0110] S706, obtaining a pressure change curve of the fuel tank system;

[0111] S707, obtaining a second comparison result according to the pressure change curve and the preset change curve;

[0112] S708, adjusting the opening and closing combination to the third combination;

[0113] S709, obtaining a pressure drop curve of the fuel tank system;

[0114] S710, obtaining a third comparison result according to the pressure drop curve and the preset drop curve;

[0115] S711. Generate fuel tank system leakage alarm information according to the first comparison result, the second comparison result, and / or the third comparison result.

[0116] In some optional embodiments, the vent valve and the carbon canister valve are both closed, the first valve body is opened, and the multi-way valve is switched to connect the pressure stabilizing chamber to the carbon canister; gas is compressed by the turbocharger and then delivered to the carbon canister through the first duct, and the first air inlet of the carbon canister delivers the gas to the fuel tank to increase the fuel tank pressure; a fuel tank pressure rise curve is obtained; a first comparison result is obtained based on the pressure rise curve and a preset rise curve; when the fuel tank pressure reaches a set value, the multi-way valve is closed; a fuel tank pressure change curve is obtained; a second comparison result is obtained based on the pressure change curve and a preset change curve; the multi-way valve is opened to connect the vent valve to the carbon canister; a fuel tank pressure drop curve is obtained; a third comparison result is obtained based on the pressure drop curve and a preset drop curve; and a fuel tank and pipeline leakage alarm is generated based on the first comparison result, the second comparison result, and the third comparison result. Specifically, after the first valve body is closed, a leak test of the fuel tank and the carbon canister can be performed simultaneously, that is, the carbon canister is vented after the first valve body is closed to detect whether the carbon canister pressure change curve meets the preset curve.

[0117] Specifically, referring to Figure 1 , when the entire system requires leak diagnosis, the vent valve 1 is controlled to close, the carbon canister valve 5 is closed, the first valve body 6 is opened, and the multi-way valve 2 connects the two paths between the carbon canister 3 and the pressure-stabilizing chamber 7. The turbocharger 14 increases the pressure within the intake pipe 11, causing the gas in the intake pipe 11 to flow from the intercooler 16 → the second valve body 8 → the pressure-stabilizing chamber 7 → the multi-way valve 2 → the carbon canister 3 → the first valve body 6 → the fuel tank 4. Upon entering the fuel tank 4, a pressure higher than atmospheric pressure is formed within the fuel tank 4. During the pressure increase process in the fuel tank 4, the preset rising curve has a certain fluctuation range, and compliance is considered within this fluctuation range. If the pressure rise curve conforms to the preset rising curve, the carbon canister valve 5 is considered to be opening and closing normally. If the pressure rise curve is slower than the preset rising curve, the carbon canister valve 5 is considered to be opening and closing abnormally.

[0118] After the pressure in fuel tank 4 reaches a preset value, multi-way valve 2 is closed and leak diagnosis is initiated. The pressure fluctuations within fuel tank 4 are monitored. If the pressure change curve matches the preset curve, multi-way valve 2 is diagnosed as closing normally. If the pressure drops faster than the preset rate, multi-way valve 2 is diagnosed as closing abnormally. If the pressure drops normally, vent valve 1 of the three-way switching valve is opened. If the pressure drop curve matches the preset curve, vent valve 1 is diagnosed as functioning normally. Otherwise, vent valve 1 is diagnosed as functioning abnormally. A fuel tank leak alarm is generated if at least one of the canister valve 5, multi-way valve 2, or vent valve 1 is closing abnormally.

[0119] 3-4 , during the operation of the engine 12 , by adjusting the regulating valve 10 for the upstream purge of the carbon canister 3 , the temperature of the gas flow participating in the desorption process of the carbon canister 3 before and after the intercooler 16 can be adjusted, and the purge efficiency of the carbon canister 3 can be improved by adjusting the gas temperature of the purge flow of the carbon canister 3 .

[0120] In some optional embodiments, referring to FIG. 2 , when leak diagnosis is required for the entire system, the vent valve 1 is controlled to close, the carbon canister valve 5 is closed, and the multi-way valve 2 connects the two channels of the carbon canister 3 and the pressure-sustaining chamber 7. The pressure in the main air pipe is increased by the turbocharger 14. The gas in the main air pipe flows from the intercooler 16 → the second valve body 8 → the pressure-sustaining chamber 7 → the multi-way valve 2 → the carbon canister 3 → the first valve body 6 → the fuel tank 4, resulting in an internal pressure within the fuel tank 4 that is higher than atmospheric pressure. This allows for leak detection in the fuel tank 4.

[0121] The implementation of the embodiments of the present application includes the following beneficial effects: The embodiments of the present application provide a method for detecting leakage of a fuel tank system, which increases the pressure of the fuel tank through a turbocharger and detects the pressure rise curve of the fuel tank. After comparing the pressure rise curve with the preset rise curve, it is possible to quickly determine whether the carbon canister valve is closed normally. After closing the multi-way valve, the pressure change curve of the fuel tank is detected, so that it is possible to quickly determine whether the multi-way valve is closed normally according to the pressure change curve and the preset change curve. After the multi-way valve is connected to the vent valve, the pressure drop curve of the fuel tank is detected, and it is possible to quickly determine whether the vent valve is leaking according to the pressure drop curve and the preset drop curve. The fuel tank system leakage detection can also be performed when the engine is working. It is not dependent on the external atmospheric pressure and can be detected at any time. The detection frequency is high and the detection results are accurate.

[0122] Throughout this specification, references to the term "in a specific embodiment" indicate that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present application. Throughout this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0123] The above is a specific description of the preferred implementation of the present application, but the invention of the present application is not limited to the embodiments. Technical personnel familiar with the art can also make various equivalent modifications or substitutions without violating the spirit of the present application. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. A carbon canister desorption system comprising: carbon canister, fuel tank, turbocharger and intake manifold; The carbon canister is provided with a first air inlet, a second air inlet, and a first air outlet, wherein the first air inlet is connected to the fuel tank, the second air inlet is connected to a first bronchial pipe, and the first air outlet is connected to a second bronchial pipe, and the second bronchial pipe is used to transport the gas in the carbon canister to the first end of the air inlet pipe or the second end of the turbocharger; The turbocharger is used to compress the air and flow it to the carbon canister through the first duct, and to desorb the carbon canister.

2. The carbon canister desorption system according to claim 1, wherein: A main air pipe is provided between the first end of the turbocharger and the first end of the intake pipe, a throttle valve is provided on the main air pipe, the second end of the intake pipe is connected to the engine, the intake pipe is used to transport the gas at the first end of the intake pipe to the engine, and the first branch pipe is connected to the main air pipe at the first end of the turbocharger.

3. The carbon canister desorption system according to claim 2, wherein: The first bronchial pipe, the carbon canister and the second bronchial pipe form a desorption pipeline, and the desorption pipeline is provided with a carbon canister valve, a multi-way valve and a valve group.

4. The carbon canister desorption system according to claim 3, wherein: An intercooler is provided on the main air pipe, and the first branch pipe is communicated with the first end, the second end or the intercooler of the intercooler.

5. The carbon canister desorption system according to claim 2, wherein: The second bronchus is communicated with the first end of the air inlet pipe.

6. The carbon canister desorption system according to claim 2, wherein: The second bronchial pipe is in communication with the second end of the turbocharger.

7. The carbon canister desorption system according to claim 4, wherein: The first branch pipe of the desorption pipeline includes a first branch pipe, a second branch pipe, a third branch pipe and a regulating valve. The first end of the third branch pipe is connected to the second air inlet, the second end of the third branch pipe is connected to the first end of the second branch pipe and the first end of the first branch pipe respectively, the second end of the first branch pipe is connected to the first end of the intercooler, and the second end of the second branch pipe is connected to the second end of the intercooler. The regulating valve is located at the intersection of the first branch pipe, the second branch pipe and the third branch pipe, and the regulating valve is used to adjust the ratio of the third branch pipe connecting to the first branch pipe and the second branch.

8. The carbon canister desorption system according to claim 3, wherein: A pressure stabilizing chamber and a flow limiting valve are provided on the desorption pipeline.

9. A carbon canister desorption method, wherein:

18. The system of claim 17, wherein the air intake pipe is an intake manifold and an intake duct is connected to the intake manifold, wherein the intake manifold has a first port and a second port. The air intake manifold has a first port and a second port. The air intake manifold has a first port and a second port. The air intake manifold has a second port and a second port. The air intake manifold has a second port and a second port. When it is detected that the engine is in a first preset working state, closing the vent valve and switching the multi-way valve so that the first branch pipe is connected to the carbon canister; adjusting a pressure difference between a first end and a second end of the throttle valve through the turbocharger and the throttle valve; delivering the gas from the first end of the turbocharger to the carbon canister through the first duct, so that the gas is desorbed from the carbon canister; The desorbed gas is delivered to the first end of the intake pipe through the second branch pipe, and the desorbed gas is delivered to the engine through the second end of the intake pipe.

10. A carbon canister desorption method, wherein:

18. The method of claim 17, wherein the air intake pipe is an intake manifold and an intake duct is connected to the intake manifold so as to provide a plurality of exhaust manifolds, wherein the exhaust manifold has an intake manifold and an intake duct, and the plurality of exhaust manifolds are connected to the intake manifold so as to provide a plurality of exhaust manifolds. When it is detected that the engine is in a second preset working state, closing the vent valve and switching the multi-way valve to connect the first branch pipe to the carbon canister; adjusting the pressure at the first end of the throttle valve through the turbocharger and the throttle valve; delivering the gas from the first end of the turbocharger to the carbon canister through the first duct, so that the gas is desorbed from the carbon canister; The second branch pipe delivers the desorbed gas to the second end of the turbocharger, so that the turbocharger delivers the desorbed gas to the intake pipe through the main air pipe, and then delivers the desorbed gas to the engine through the intake pipe.

11. The method according to claim 9 or 10, wherein: An intercooler is connected to the main air pipe at the first end of the throttle valve, the first branch pipe includes a regulating valve, a first branch pipe, a second branch pipe, and a third branch pipe, the first end of the third branch pipe is connected to the second air inlet, the second end of the third branch pipe is connected to the first end of the second branch pipe and the first end of the first branch pipe respectively, the second end of the first branch pipe is connected to the first end of the intercooler, and the second end of the second branch pipe is connected to the second end of the intercooler, a carbon canister valve, a multi-way valve, and a valve group are provided on the desorption pipeline, and the method further includes: When it is detected that the engine is in a third preset operating state, closing the vent valve and switching the multi-way valve to connect the first branch pipe to the carbon canister; regulating the pressure at a first end of the turbocharger via the turbocharger and the throttle valve; The temperature of the desorbed gas is adjusted by adjusting the gas ratio at the first end or the second end of the intercooler through the regulating valve. The desorbed gas flows into the desorption pipeline and enters the carbon canister to desorb the carbon canister.

12. A method for detecting leakage in a fuel tank system, wherein:

18. The method of claim 17, wherein the air intake pipe is an intake pipe having an intake duct and an intake duct, and the intake duct has an intake duct that is adapted to receive the air from the exhaust pipe and the intake duct has an intake duct that is adapted to receive the air from the exhaust pipe. By adjusting the opening and closing combination to the first combination, the fuel tank system forms a relatively closed space; By adjusting the opening and closing combination, the turbocharger compresses the gas and transmits it to the fuel tank through the first bronchial pipe, so that the pressure of the fuel tank system increases; Obtaining a pressure rise curve of the fuel tank system; Obtaining a first comparison result according to the pressure rise curve and a preset rise curve; When the pressure of the oil tank system reaches a set value, adjusting the opening and closing combination to a second combination; Obtaining a pressure change curve of the fuel tank system; Obtaining a second comparison result according to the pressure change curve and a preset change curve; Adjusting the opening and closing combination to a third combination; obtaining a pressure drop curve of the fuel tank system; Obtaining a third comparison result according to the pressure drop curve and a preset drop curve; Fuel tank system leakage alarm information is generated according to the first comparison result, the second comparison result and / or the third comparison result.

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