CN113417765B

CN113417765B - Positive pressure detection device and method and vehicle comprising device

Info

Publication number: CN113417765B
Application number: CN202110693465.XA
Authority: CN
Inventors: 顾峰
Original assignee: Zhejiang Geely Holding Group Co Ltd; Geely Automobile Research Institute Ningbo Co Ltd
Current assignee: Zhejiang Geely Holding Group Co Ltd; Geely Automobile Research Institute Ningbo Co Ltd
Priority date: 2021-06-22
Filing date: 2021-06-22
Publication date: 2023-05-16
Anticipated expiration: 2041-06-22
Also published as: CN113417765A

Abstract

The invention provides a positive pressure detection device, a positive pressure detection method and a vehicle comprising the device, which belong to the technical field of internal combustion engines, wherein the positive pressure detection device comprises: a fuel tank, a carbon canister, a positive pressure generator, an engine, a fuel vapor concentration detector, a self-circulation conduit, and a controller. The fuel tank is provided with an exhaust port and an oil outlet; the carbon tank is provided with an atmosphere communication port, an adsorption port and a desorption port, and the adsorption port is communicated with the exhaust port; the positive pressure generator is arranged on the atmosphere communication port, and the air blowing port is communicated with the atmosphere communication port; the engine is provided with an oil inlet and an air inlet, the oil inlet is communicated with the oil outlet, and the air inlet is provided with an air inlet pipeline; the fuel vapor concentration detector is arranged on the desorption pipeline; one end of the self-circulation pipeline is communicated with the desorption pipeline, and the other end of the self-circulation pipeline is communicated with the adsorption pipeline; the controller is electrically connected with the fuel vapor concentration detector and the positive pressure generator. The concentration can be detected without starting the engine.

Description

Positive pressure detection device and method and vehicle comprising device

Technical Field

The invention relates to the technical field of internal combustion engines, in particular to a positive pressure detection device and method and a vehicle comprising the device.

Background

In order to reduce the pollution of evaporative emissions of automobiles to the atmosphere, the national emission restrictions on automobiles are becoming more and more stringent. Because of the characteristic of easy volatilization of fuel such as gasoline, methanol, etc., a carbon tank loaded with active carbon powder is generally used for adsorbing fuel steam at present, so that the volatilized fuel steam is prevented from polluting the environment. When the engine is running, the adsorbed gas is desorbed from the activated carbon tank by the negative pressure of the engine and is sucked into the engine for combustion, so that the environmental pollution is reduced.

However, the simple use of a canister for adsorption has the following disadvantages: on one hand, with the popularization of hybrid electric vehicles and the application of technologies such as turbocharging, the running time and the negative pressure vacuum degree of an engine are reduced, and more active carbon powder is required to be loaded for adsorbing fuel vapor generated during filling, so that the concentration of the fuel vapor in the air entering a combustion chamber can be higher; on the other hand, the limit value of the automobile exhaust emission is gradually increased due to the requirement of environmental protection, so that the control requirement of the proportion of fuel and air entering the engine is more accurate. In addition, the desorption process can be completed by starting the engine, so that the oil injection quantity of the engine during desorption cannot be accurately controlled. The three aspects lead the desorption process of the activated carbon powder to be controlled more accurately, thereby reducing the problems of increasing exhaust emission pollutants or engine fire and the like caused by the deviation of the air-fuel ratio from an ideal proportion due to the fact that the air mixed with fuel steam enters a combustion chamber to participate in combustion. Accordingly, it is desirable to provide a positive pressure detection apparatus, method, and vehicle incorporating the apparatus.

Disclosure of Invention

In view of the above drawbacks of the prior art, an object of the present invention is to provide a positive pressure detection device, a positive pressure detection method, and a vehicle including the same, for improving the problem that only canister desorption is currently used to cause a higher air-fuel ratio, and at the same time, the engine desorption process needs to be started to detect the concentration of fuel vapor in the canister.

To achieve the above and other related objects, the present invention provides a positive pressure detection device comprising: a fuel tank, a carbon canister, a positive pressure generator, an engine, a fuel vapor concentration detector, a self-circulation conduit, and a controller.

The fuel tank is provided with an exhaust port and an oil outlet;

the carbon tank is provided with an atmosphere communication port, an adsorption port and a desorption port, and the adsorption port is communicated with the exhaust port through an adsorption pipeline;

the positive pressure generator is arranged on the atmosphere communication port, the air blowing port is communicated with the atmosphere communication port, and the air suction port is communicated with the atmosphere;

an oil inlet and an air inlet are formed in the engine, the oil inlet is communicated with the oil outlet through a fuel input pipeline, an air inlet pipeline is communicated with the air inlet, and the desorption port is communicated with the air inlet pipeline through a desorption pipeline;

the fuel vapor concentration detector is arranged on the desorption pipeline;

one end of the self-circulation pipeline is communicated with a desorption pipeline between the fuel vapor concentration detector and the air inlet pipeline, and the other end of the self-circulation pipeline is communicated with the adsorption pipeline;

the controller is electrically connected with the fuel vapor concentration detector and the positive pressure generator respectively.

In an embodiment of the invention, the oil inlet is formed on an oil rail of the engine.

In an embodiment of the present invention, a first throttle valve is installed on the adsorption pipeline, the first throttle valve is electrically connected with the controller, and the self-circulation pipeline is communicated with the adsorption pipeline between the adsorption port and the first throttle valve.

In an embodiment of the present invention, a second throttle valve is installed on the fuel input pipe, and the second throttle valve is electrically connected with the controller.

In an embodiment of the present invention, a third throttle valve is installed on a desorption pipe between the fuel vapor concentration detector and the air intake pipe, the third throttle valve is electrically connected to the controller, and the self-circulation pipe is connected to the desorption pipe between the fuel vapor concentration detector and the first throttle valve.

In an embodiment of the present invention, a fourth throttle valve is installed on the air intake pipe, and the fourth throttle valve is electrically connected with the controller.

In an embodiment of the present invention, there is also provided a positive pressure detection method, including the following steps:

s1, detecting the concentration of fuel vapor in a carbon tank at a set time point when the engine is not started for desorption;

s2, if the detected concentration of the fuel vapor reaches a desorption standard, carrying out desorption on the carbon tank according to a preset desorption strategy;

s3, during desorption, according to the detected concentration of the fuel vapor in the carbon tank, the initial fuel injection quantity of the engine is regulated, and the air-fuel ratio of the engine is controlled.

In an embodiment of the present invention, the preset desorption strategy includes adjusting the desorption pipeline to be gradually opened, and correspondingly adjusting the fuel input pipeline of the engine to be gradually closed at the same time; and then adjusting the desorption pipeline to be gradually closed, and correspondingly adjusting the fuel oil input pipeline of the engine to be gradually opened at the same time.

In an embodiment of the present invention, step S2 includes the following processes:

s21, judging whether the concentration of the fuel vapor in the carbon tank reaches a preset desorption standard, if so, carrying out desorption, otherwise, keeping the original state;

s22, closing an adsorption pipeline, a positive pressure generator and a fuel vapor concentration detector, and opening the desorption pipeline, wherein fuel vapor in the carbon tank enters the engine under the action of negative pressure in an air inlet pipeline;

s23, regulating and controlling the opening degree of the fuel input pipeline and the desorption pipeline according to the preset desorption strategy and the current fuel vapor concentration in the carbon tank.

In an embodiment of the present invention, there is also provided a vehicle including the positive pressure detection device described in any one of the above.

In summary, the invention sweeps the fuel vapor in the carbon tank through the positive pressure generator, and detects the current fuel vapor concentration in the carbon tank by using the fuel vapor concentration detector, and when the desorption standard is reached, the desorption is carried out according to the desorption strategy. The desorption process is accurately controlled, and the exhaust emission pollutants are reduced.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a positive pressure detecting device according to an embodiment of the invention;

FIG. 2 is a flow chart of a positive pressure detecting method according to an embodiment of the invention;

FIG. 3 is a flow chart of step S1 according to an embodiment of the invention;

FIG. 4 is a flow chart of step S2 according to an embodiment of the invention;

fig. 5 is a graph illustrating a desorption strategy according to an embodiment of the present invention.

Description of element numbers:

100. a fuel tank; 101. an exhaust port; 102. an oil outlet;

200. a carbon tank; 201. an atmosphere communication port; 202. an adsorption port; 203. a desorption port; 204. an adsorption pipeline; 205. a first throttle valve; 206. an atmosphere communicating pipe;

300. a positive pressure generator;

400. an engine; 401. an oil inlet; 402. an air inlet; 403. a fuel oil input pipe; 404. a second throttle valve; 405. a desorption line; 406. a third throttle valve; 407. an oil rail; 408. an air intake duct; 409. a fourth throttle valve;

500. a fuel vapor concentration detector;

600. a self-circulation pipe;

700. and a controller.

Detailed Description

Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention. It should be noted that the following embodiments and features in the embodiments may be combined with each other without conflict. It is also to be understood that the terminology used in the examples of the invention is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the invention. The test methods in the following examples, in which specific conditions are not noted, are generally conducted under conventional conditions or under conditions recommended by the respective manufacturers.

Please refer to fig. 1 to 5. It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the invention to the extent that it can be practiced, since modifications, changes in the proportions, or adjustments of the sizes, which are otherwise, used in the practice of the invention, are included in the spirit and scope of the invention which is otherwise, without departing from the spirit or scope thereof. Also, the terms such as "upper," "lower," "left," "right," "middle," and "a" and the like recited in the present specification are merely for descriptive purposes and are not intended to limit the scope of the invention, but are intended to provide relative positional changes or modifications without materially altering the technical context in which the invention may be practiced.

Where numerical ranges are provided in the examples, it is understood that unless otherwise stated herein, both endpoints of each numerical range and any number between the two endpoints are significant both in the numerical range. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs and to which this invention belongs, and any method, apparatus, or material of the prior art similar or equivalent to the methods, apparatus, or materials described in the examples of this invention may be used to practice the invention.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a positive pressure detecting device according to an embodiment of the invention. The invention provides a positive pressure detection device. The fuel vapor in the canister 200 is purged into the fuel tank 100 by the positive pressure generator 300, and the concentration of the fuel vapor in the canister 200 is detected at the present time using the fuel vapor concentration detector 500, and when the predetermined concentration is reached, desorption is performed according to a preset desorption strategy. The invention can detect the concentration of fuel vapor in the activated carbon powder without starting the desorption process of the engine 400, thereby accurately controlling the desorption process, improving the desorption efficiency and greatly reducing the exhaust emission pollutants.

Referring to fig. 1, in an embodiment of the present invention, the positive pressure detecting apparatus includes a fuel tank 100, a canister 200, a positive pressure generator 300, an engine 400, a fuel vapor concentration detector 500, a self-circulation pipe 600, and a controller 700.

The fuel tank 100 is for storing fuel required for combustion of the engine 400, and is provided with an exhaust port 101 and an oil outlet 102. The fuel stored in the fuel tank 100 is a volatile liquid, such as gasoline, methanol, etc., and fuel vapor generated by the volatilization of the fuel enters the carbon canister 200 through the exhaust port 101 to be adsorbed, so that the fuel vapor is prevented from volatilizing to the atmosphere to pollute the air.

The canister 200 is installed between the fuel tank 100 and the engine 400, and is filled with activated carbon particles having high adsorptivity, for adsorbing fuel vapor volatilized in the fuel tank 100. The canister 200 is provided with an atmosphere communication port 201, an adsorption port 202 and a desorption port 203, wherein the adsorption port 202 is communicated with the exhaust port 101 through an adsorption pipe 204, and the atmosphere communication port 201 is communicated with the atmosphere through an atmosphere communication pipe 206.

The positive pressure generator 300 is mounted on the atmosphere communication port 201. An air outlet (not shown in the figure) of the positive pressure generator 300 communicates with the atmosphere communication port 201, and an air inlet (not shown in the figure) of the positive pressure generator 300 communicates with the atmosphere. Wherein the positive pressure generator 300 is installed at one side of the atmospheric communication tube 206 near the atmospheric communication port 201, and generates a forward air flow to purge the canister 200.

The engine 400 is provided with an oil inlet 401 and an air inlet 402, the oil inlet 401 is communicated with the oil outlet 102 through a fuel input pipeline 403, the air inlet 402 is communicated with an air inlet pipeline 408, and the desorption port 203 is communicated with the air inlet pipeline 408 through a desorption pipeline 405 and is communicated with the air inlet 402. Fuel in the fuel tank 100 is sucked into the engine 400 through the fuel input pipe 403.

The fuel vapor concentration detector 500 is mounted on the desorption pipe 405 to facilitate detection of the fuel vapor concentration in the canister 200. In one embodiment of the present invention, the concentration of fuel vapor in the present invention is: the fuel vapor concentration detector 500 detects the proportion of the carbon element and the hydrogen element in the carbon tank 200 to the fuel vapor flowing out, that is, the proportion of the carbon element and the hydrogen element in the carbon tank 200 to the fuel vapor in the carbon tank 200.

The self-circulation line 600 communicates with the adsorption line 204 and the desorption line 405. Wherein one end of the self-circulation pipe 600 is connected to the desorption pipe 405 between the fuel vapor concentration detector 500 and the intake pipe 408, and the other end of the self-circulation pipe 600 is connected to the adsorption pipe 204. Thereby allowing the carbon canister 200 to communicate with the fuel tank 100 and the fuel vapor in the engine 400.

The controller 700 is electrically connected to the fuel vapor concentration detector 500 and the positive pressure generator 300, respectively, and controls the opening and closing of the two according to the desorption requirement.

In order to realize automatic control of each element in the positive pressure detection device, in an embodiment of the present invention, the controller 700 is an ECU (Electronic Control Unit ) and is composed of a microprocessor, a memory, an input/output interface, an analog-to-digital converter, and a large-scale integrated circuit for shaping, driving, etc., so that the working efficiency of the engine 400 is effectively improved by optimizing the data of ignition, oil injection, etc. of the engine 400.

In one embodiment of the present invention, the oil inlet 401 is formed in the oil rail 407 of the engine 400. Fuel is drawn from within fuel tank 100 through fuel inlet conduit 403 and stored in the interior cavity of fuel rail 407 to provide a supply of fuel for combustion by engine 400. An oil amount limiting valve (not shown) for limiting the amount of fuel injected into each cylinder so that the amount of fuel injected into each cylinder is uniform may be further attached to the oil rail 407.

In an embodiment of the present invention, the adsorption pipe 204 is provided with a first throttle valve 205, the first throttle valve 205 is electrically connected to the controller 700, and the self-circulation pipe 600 is connected to the adsorption pipe 204 between the adsorption port 202 and the first throttle valve 205. The desorption pipe 405 is provided with a third throttle valve 406, the third throttle valve 406 is electrically connected with the controller 700, and the self-circulation pipe 600 is communicated with the desorption pipe 405 between the fuel vapor concentration detector 500 and the third throttle valve 406. When the concentration of fuel vapor in the canister 200 needs to be detected, the controller 700 opens the first throttle valve 205, the positive pressure generator 300 and the fuel vapor concentration detector 500, closes the third throttle valve 406, and simultaneously keeps the second throttle valve 404 and the fourth throttle valve 409 unchanged, and after the positive pressure generator 300 blows forward flow, the fuel vapor in the canister 200 flows through the desorption pipe 405, the self-circulation pipe 600 and the adsorption pipe 204 in order and then enters the fuel tank 100, and at this time, the fuel vapor concentration detector 500 can be used to detect the concentration of fuel vapor in the canister 200. When the detected concentration value reaches the desorption standard and desorption is required, the controller 700 closes the first throttle valve 205, the positive pressure generator 300 and the fuel vapor concentration detector 500 so that the fuel vapor in the canister 200 and the fuel tank 100 cannot flow through each other. And opens the third throttle valve 406, the second throttle valve 404 and the fourth throttle valve 409 are opened since desorption is performed after the engine 400 is started. Fuel vapor stored in the canister 200 is forced into the intake port 402 of the engine 400 by the negative pressure of the intake conduit 408 through the third throttle valve 406. This effectively prevents fuel vapor remaining in the fuel tank 100 from flowing into the canister 200, and improves desorption efficiency. Meanwhile, the occurrence of the collapse of the fuel tank 100 due to the negative pressure can be effectively prevented. By closing the first throttle valve 205, fuel vapor within the fuel tank 100 is prevented from entering the canister 200 through the adsorption conduit 204. In addition, in order to improve the situation of multiple desorption of the engine 400, in an embodiment of the present invention, when the engine 400 is not started for desorption, since the third throttle valve 406 is closed, when the desorption condition is not reached, the engine 400 does not need to perform desorption on the carbon canister 200 frequently too early, thereby improving the desorption efficiency. When the engine 400 is started for desorption, the controller 700 opens the third throttle valve 406, and controls the opening of the third throttle valve 406 to be gradually adjusted to the maximum according to a preset desorption strategy, and then gradually adjusted to be closed.

To ensure that the air-fuel ratio of the engine 400 is controlled to be in an ideal state, in an embodiment of the present invention, a second throttle valve 404 is mounted on the fuel input pipe 403, and the second throttle valve 404 is electrically connected to the controller 700. When the engine 400 is started but not desorbed, the controller 700 may maintain the second throttle valve 404 open and fuel in the fuel tank 100 is drawn into the fuel rail 407 through the fuel input conduit 403. After the desorption is started, according to a preset desorption strategy, when the opening of the third throttle valve 406 is controlled to be gradually adjusted to be maximum and then gradually adjusted to be closed, the controller 700 correspondingly controls the second throttle valve 404 to gradually adjust the opening to be minimum and then gradually adjusted to be in a normal state, so that the engine 400 keeps stable fuel gas input.

In an embodiment of the present invention, the non-desorbed state of the engine 400 further includes a non-started state of the engine 400 in which the fuel tank 100 does not need to supply fuel to the engine 400, and thus the controller 700 may control the second throttle valve 404 to maintain the closed state, the first throttle valve 205 to maintain the open state, and the third throttle valve 406 to maintain the closed state, so that the fuel gas in the fuel tank 100 may enter the canister 200.

In an embodiment of the present invention, a fourth throttle valve 409 is installed on the air inlet pipe 408, and the fourth throttle valve 409 is electrically connected to the controller 700. A fourth throttle valve 409 is mounted on the inlet conduit 408 on the side of the desorption conduit 405 remote from the inlet 402, the fourth throttle valve 409 being connected to the controller 700 by electrical wiring. Atmospheric air is admitted to the engine 400 through the intake conduit 408, continuously providing an air supply for gasoline or diesel combustion within the engine 400.

Referring to fig. 1 and 2, fig. 2 is a flow chart of a positive pressure detection method according to an embodiment of the invention, and in an embodiment of the invention, a positive pressure detection method is further provided, which includes the following steps:

s1, when the engine 400 is not started for desorption, the concentration of the fuel vapor in the carbon tank 200 is detected at a set time point.

S2, if the detected fuel vapor concentration reaches the desorption standard, the carbon tank 200 is desorbed according to a preset desorption strategy.

S3, during desorption, according to the detected concentration of fuel vapor in the carbon tank 200, the initial fuel injection quantity of the engine 400 is adjusted, and the air-fuel ratio of the engine 400 is controlled.

Referring to fig. 1 and 3, fig. 3 is a flow chart of step S1 in an embodiment of the invention, and step S1 includes the following steps:

and S11, when the engine 400 is not started for desorption, judging the current working condition of the engine 400, if the engine 400 is not started, keeping the second throttle valve 404 and the fourth throttle valve 409 in a closed state by the controller 700, otherwise, keeping the second throttle valve 404 and the fourth throttle valve 409 in an open state by the controller 700.

In this step, since the engine 400 is not started and the desorption includes two different situations that the engine 400 is not started and the engine 400 is started but the canister 200 is not desorbed, in an embodiment of the present invention, the current working condition of the engine 400 is determined according to the on-off state of the engine 400. If the engine 400 is not started, it is not necessary to draw fuel from the fuel tank 100, and the outside atmosphere does not enter the engine 400 through the intake pipe 408, so the controller 700 maintains the second throttle valve 404 and the fourth throttle valve 409 in the closed state. If the engine 400 is started but not yet desorbed from the canister 200, the controller 700 maintains the second and

fourth throttles

404 and 409 open. The engine 400 draws fuel from the fuel tank 100 while ambient atmosphere enters the engine 400 through the intake conduit 408 and is combusted within the engine 400 after being mixed with the fuel.

S12, when the fuel vapor concentration in the canister 200 is detected at the set time point, the controller 700 closes the third throttle valve 406, and opens the positive pressure generator 300, the fuel vapor concentration detector 500, and the first throttle valve 205, thereby generating a positive flow of fuel vapor to purge the canister 200.

To facilitate detection of the concentration of fuel vapor within the current canister 200, in one embodiment of the invention, the controller 700 turns on the positive pressure generator 300 and the fuel vapor concentration detector 500 and closes the third throttle valve 406 while maintaining the state of the second throttle valve 404 and the fourth throttle valve 409 unchanged, and the positive flow of gas generated by the positive pressure generator 300 sweeps the fuel vapor within the canister 200, and the fuel vapor concentration detector 500 timely detects the concentration levels of carbon and hydrogen in the flowing fuel vapor as it flows through the desorption conduit 405 and feeds back the current concentration to the controller 700. While the first throttle valve 205 is closed in order to avoid fuel vapor entering the intake conduit 408 and eventually entering the engine 400 causing premature desorption.

It should be noted that, in an embodiment of the present invention, the set time point refers to that the engine 400 detects the concentrations of the carbon element and the hydrogen element in the fuel vapor through the controller 700 according to the self-operation condition. When the engine 400 is in a preferred operating state, e.g., it is not operating in a water-deficient state, information to detect the concentration of fuel vapor in the canister 200 is sent to the controller 700, and the controller 700 opens the fuel vapor concentration detector 500, the positive pressure generator 300, the first throttle valve 205, and closes the third throttle valve 406 to detect the concentration of fuel vapor in the canister 200. After the detection is completed, the controller 700 controls the positive pressure generator 300 and the fuel vapor concentration detector 500 to be turned off and to perform detection again at a proper time.

S13, the fuel vapor in the canister 200 is introduced into the fuel tank 100 through the desorption line 405, the self-circulation line 600, and the adsorption line 204 in this order.

In an embodiment of the present invention, during the detection of the concentration of fuel vapor, the third throttle valve 406 is closed, the first throttle valve 205 is opened, and under the purging of the forward air flow, the fuel vapor in the canister 200 flows through the desorption pipe 405, the self-circulation pipe 600 and the adsorption pipe 204 in sequence, and finally is stored in the fuel tank 100, and after waiting for the detection, the fuel vapor is re-introduced into the canister 200 from the exhaust port 101 of the fuel tank 100.

Referring to fig. 1 and 4, fig. 4 is a flowchart of step S2 in an embodiment of the invention, and step S2 includes the following steps:

s21, judging whether the concentration of the fuel vapor in the carbon tank 200 reaches a preset desorption standard, if so, carrying out desorption, otherwise, keeping the original state.

In order to reduce the number of times the engine 400 is started to desorb and improve the operation efficiency, in an embodiment of the present invention, by determining whether the concentration of fuel vapor in the canister 200 has reached the preset desorption standard, if the concentration of fuel vapor in the canister 200 has reached the desorption standard, desorption is performed. In one embodiment of the invention, the desorption criterion may be set to 40% taking into consideration all aspects of the factors. When the fuel vapor concentration detector 500 detects that the carbon element to hydrogen element ratio in the canister 200 exceeds 40%, the canister 200 is desorbed.

If the fuel vapor concentration does not reach the preset desorption standard, the controller 700 turns off the positive pressure generator 300 and the fuel vapor concentration detector 500, and the canister 200 returns to the adsorption state. Due to the diffusion movement of the molecules, the fuel vapor stored in the fuel tank 100 is diffused into the carbon tank 200 through the adsorption pipeline 204, and after the activated carbon in the carbon tank 200 adsorbs carbon elements and hydrogen elements in the fuel vapor, the adsorbed fuel vapor is discharged into the atmosphere through the atmosphere communicating pipe 206, so that the atmospheric pollution is effectively avoided.

S22, the controller 700 closes the first throttle valve 205, the positive pressure generator 300, and the fuel vapor concentration detector 500, and opens the third throttle valve 406, and the fuel vapor in the canister 200 enters the engine 400.

In one embodiment of the invention, desorption is initiated when the fuel vapor concentration in the canister 200 reaches the desorption criteria. The controller 700 closes the first throttle valve 205 and the positive pressure generator 300, opens the third throttle valve 406, and opens the second throttle valve 404 and the fourth throttle valve 409 since desorption is performed after the engine 400 is operated. After the atmospheric air flows into the air inlet pipeline 408, the generated negative pressure drives the fuel vapor in the carbon tank 200 to enter the air inlet pipeline 408 through the desorption pipeline 405 and finally enter the engine 400, so as to provide certain fuel supply for the combustion of the engine 400.

S23, according to a preset desorption strategy and the current concentration of fuel vapor in the carbon tank 200, the controller 700 regulates the opening degree of the second throttle valve 404 and the third throttle valve 406.

Referring to fig. 1, 4 and 5, fig. 5 is a graph illustrating a desorption strategy according to an embodiment of the present invention, wherein the desorption strategy is a graph of a preset flow versus time according to a flow rate of fuel vapor flowing through the desorption pipe 405. In fig. 5, Q is the flow rate of the fuel vapor through the desorption line 405, t is the corresponding time, and the percentage is the concentration of the fuel vapor in the canister 200. According to the current fuel vapor concentration and with the desorption strategy, the controller 700 gradually opens the third throttle valve 406 to a maximum value, then gradually reduces the third throttle valve 406 until the third throttle valve is closed, simultaneously, correspondingly gradually reduces the second throttle valve 404 to be closed, and then gradually opens the second throttle valve 404 to an initial value. The fuel vapor flowing through the third throttle valve 406 is allowed to steadily rise to a maximum operating flow rate for a short period of time and slowly drop to a zero value. While lowering the fuel supplied from fuel tank 100 to engine 400 as the fuel vapor increases in intake port 402, maintaining the air-fuel ratio at a desired level. Therefore, the desorption with large ratio can be rapidly completed, the running time of large flow is reduced, and the noise during desorption is reduced. In order to make the image clear, only a plurality of curves of the flow and time relationship are schematically drawn in the figure, and when the fuel vapor concentration is greater than the preset desorption standard in practical engineering application, the corresponding curves can be checked.

In one embodiment of the present invention, the initial fuel injection amount is adjusted accordingly according to the concentration of fuel vapor, so that the ratio of air to fuel in the engine 400 is maintained at an ideal state. Preferably, in one embodiment of the present invention, the engine 400 has an air-fuel ratio of 14.7:1, which can achieve the optimal combustion state and reduce the exhaust emissions.

In an embodiment of the present invention, there is also provided a vehicle on which the positive pressure detection device according to any one of the above is mounted, and the positive pressure detection device may use the positive pressure detection method according to any one of the above.

In summary, the invention uses the positive pressure generator to purge the fuel vapor in the carbon tank, and uses the fuel vapor concentration detector to detect the fuel vapor concentration in the carbon tank, and when the desorption standard is reached, the desorption is carried out according to the desorption strategy. By accurately controlling the desorption process, the desorption efficiency of the activated carbon powder is improved, and the pollutant emission of tail gas is reduced. Therefore, the invention effectively overcomes some practical problems in the prior art, thereby having high utilization value and use significance.

The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims

1. A positive pressure detection device, comprising:

the fuel tank is provided with an exhaust port and an oil outlet;

the positive pressure generator is arranged on the atmosphere communication port, the air blowing port of the positive pressure generator is communicated with the atmosphere communication port, and the air suction port of the positive pressure generator is communicated with the atmosphere;

the engine is provided with an oil inlet and an air inlet, the oil inlet is communicated with the oil outlet through a fuel input pipeline, the air inlet is communicated with an air inlet pipeline, and the desorption port is communicated with the air inlet pipeline through a desorption pipeline;

a fuel vapor concentration detector mounted on the desorption pipe;

one end of the self-circulation pipeline is communicated with the desorption pipeline between the fuel vapor concentration detector and the air inlet pipeline, and the other end of the self-circulation pipeline is communicated with the adsorption pipeline;

the controller is respectively and electrically connected with the fuel vapor concentration detector and the positive pressure generator;

the engine is not required to be started, and the concentration of fuel vapor is detected; when the concentration of the fuel vapor in the carbon tank is detected, the positive pressure generator is started to generate forward airflow to purge the fuel vapor in the carbon tank, so that the fuel vapor in the carbon tank sequentially passes through the desorption pipeline, the self-circulation pipeline and the adsorption pipeline and enters the fuel tank.

2. The positive pressure detection device of claim 1, wherein the oil inlet is provided on an oil rail of the engine.

3. The positive pressure detection device according to claim 1, wherein a first throttle valve is mounted on the adsorption pipe, the first throttle valve is electrically connected to the controller, and the self-circulation pipe is connected to the adsorption pipe between the adsorption port and the first throttle valve.

4. The positive pressure detection device of claim 1, wherein a second throttle valve is mounted on the fuel input conduit, the second throttle valve being electrically connected to the controller.

5. The positive pressure detection device according to claim 1, wherein a third throttle valve is mounted on a desorption pipe between the fuel vapor concentration detector and the intake pipe, the third throttle valve is electrically connected to the controller, and the self-circulation pipe is connected to the desorption pipe between the fuel vapor concentration detector and the third throttle valve.

6. The positive pressure detection device according to claim 1, wherein a fourth throttle valve is mounted on the air intake pipe, and the fourth throttle valve is electrically connected to the controller.

7. A positive pressure detection method, characterized by being applied to the positive pressure detection apparatus according to any one of claims 1 to 6, comprising the steps of:

s3, during desorption, according to the detected concentration of the fuel vapor in the carbon tank, adjusting the initial fuel injection quantity of the engine, and controlling the air-fuel ratio of the engine;

the preset desorption strategy comprises the steps of adjusting the desorption pipeline to be gradually opened, and correspondingly adjusting the fuel oil input pipeline of the engine to be gradually closed at the same time; and then adjusting the desorption pipeline to be gradually closed, and correspondingly adjusting the fuel oil input pipeline of the engine to be gradually opened at the same time.

8. The positive pressure detection method according to claim 7, characterized in that step S2 includes the following process:

9. A vehicle, characterized in that the vehicle comprises the positive pressure detection device according to any one of claims 1 to 6.