Device and method for reducing the impact of tail gas desorption

Abstract

The present invention provides a device and method for reducing the impact of exhaust gas desorption, comprising a desorption chamber, an adsorption chamber, and a connecting chamber; the desorption chamber is connected to the connecting chamber, which is in communication with the engine's intake manifold; the adsorption chamber is connected to the connecting chamber, which is in communication with the atmospheric environment; the connecting chamber is in communication with the fuel tank; and different types of carbon powder are respectively provided in the desorption chamber, the adsorption chamber, and the connecting chamber. The beneficial effect of the present invention is that by adding an additional type of carbon powder with poor adsorption capacity to the desorption passage of the canister system, the carbon powder only participates in the desorption process and does not participate in the adsorption process, thereby reducing the rate of change of hydrocarbon concentration during the desorption process. The rate of change of hydrocarbon concentration in the mixed gas during the desorption process is gentle and does not fluctuate significantly, which can effectively ensure the combustion quality of the engine and reduce the impact of the desorption process on exhaust emissions.

Description

Technical Field

[0001] The present invention belongs to the field of automobile environmental protection, and in particular relates to a device and method for reducing the impact of exhaust gas desorption. Background Art

[0002] Environmental protection is one of the key issues in today's society, among which automobile environmental protection is the top priority. The function of automobile charcoal canister is mainly to adsorb fuel vapor from the fuel tank and prevent it from entering the atmosphere to pollute the environment. The charcoal canister desorption process is equivalent to the regeneration of the charcoal canister's adsorption capacity.

[0003] The charcoal canister desorption process mainly utilizes the negative pressure environment of the engine's intake manifold. By opening and closing the charcoal canister solenoid valve, fresh air passes through the charcoal canister and brings the hydrocarbons stored in the charcoal canister into the intake system, and then enters the engine for combustion, thereby achieving the purpose of controlling fuel evaporation emissions and repeated use of the charcoal canister.

[0004] However, due to the uncertainty of the amount of hydrocarbons stored in the charcoal canister, entering the engine will cause the combustion in the cylinder to be too lean or too rich at that moment, thereby causing an increase in the amount of exhaust pollutants.

[0005] In the existing technology, in order to deal with this problem, the engine control system calculates the concentration of hydrocarbons introduced by desorption through the rear oxygen sensor signal, and then corrects the air-fuel ratio at the next moment. This method has a hysteresis. If the change in hydrocarbon concentration is not large, it can be dealt with. However, if the concentration in the carbon canister changes greatly, it may cause the exhaust emission pollutants to deteriorate further. Summary of the Invention

[0006] In view of this, the present invention aims to propose a device and method for reducing the impact of exhaust desorption, so as to solve the problem that the existing technology has hysteresis and cannot cope with large changes in hydrocarbon concentration.

[0007] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0008] A device for reducing the impact of exhaust gas desorption, comprising a desorption chamber, an adsorption chamber, and a connecting chamber; the desorption chamber is connected to the connecting chamber, and the desorption chamber is connected to the engine's intake manifold; the adsorption chamber is connected to the connecting chamber, and the adsorption chamber is connected to the atmospheric environment; the connecting chamber is connected to a fuel tank; a solenoid valve is provided between the desorption chamber and the intake manifold; and different types of carbon powder are respectively provided in the desorption chamber, the adsorption chamber, and the connecting chamber.

[0009] Furthermore, the carbon powder in the desorption chamber is separated from the carbon powder in the connecting chamber by a desorption partition, and the carbon powder in the adsorption chamber is separated from the carbon powder in the connecting chamber by an adsorption partition; the desorption partition and the adsorption partition are both mesh partitions that only isolate solid flow.

[0010] Furthermore, the side wall of the adsorption chamber extends toward the inner side of the connecting chamber to form an adsorption channel, and the side wall of the desorption chamber extends toward the inner side of the connecting chamber to form a desorption channel.

[0011] Furthermore, the adsorption capacity of the carbon powder in the connecting cavity is higher than that of the carbon powder in the desorption cavity. The adsorption capacity of the carbon powder in the adsorption cavity is higher than that of the carbon powder in the connecting cavity.

[0012] Furthermore, a compression spring and a compression baffle are provided in the connecting chamber; the compression spring presses the compression baffle, and the compression baffle presses the carbon powder in the connecting chamber, and at the same time, the carbon powder in the connecting chamber presses the desorption partition and the adsorption partition, and the desorption partition and the adsorption partition respectively press the carbon powder in the desorption chamber and the adsorption chamber.

[0013] Furthermore, the device has the following two working states:

[0014] Adsorption state: When the device is in the adsorption state, the mixed gas containing hydrocarbons in the fuel tank passes through the connecting chamber, the adsorption channel, and the adsorption chamber in sequence before entering the atmosphere. During the process of the mixed gas entering the atmosphere from the fuel tank, the carbon powder A in the connecting chamber and the carbon powder B in the adsorption chamber adsorb the hydrocarbons in the mixed gas. At the same time, the solenoid valve is closed, and the mixed gas does not pass through the desorption chamber.

[0015] Desorption state: When the equipment is in the desorption state, the solenoid valve is opened, and under the influence of the negative pressure of the intake air at the engine end, the fresh air from the atmospheric environment passes through the adsorption chamber, adsorption channel, connecting chamber, desorption channel, and desorption chamber in sequence and enters the engine combustion chamber; in the process of fresh air entering the combustion chamber, the fresh air passes through carbon powder A, carbon powder B, and carbon powder C in the desorption chamber, and desorbs hydrocarbons to form a mixed gas containing hydrocarbons; at the same time, under the influence of the negative pressure of the intake air at the engine end, the mixed gas containing hydrocarbons in the fuel tank enters the engine combustion chamber through the connecting chamber, desorption channel, and desorption chamber.

[0016] Furthermore, the carbon powder A and carbon powder B in the device adsorbed a large amount of hydrocarbons. In the desorption state, the mixed gas passing through carbon powder A and carbon powder B contained a high concentration of hydrocarbons. At this time, carbon powder C did not adsorb too many hydrocarbons and still had good adsorption capacity. In the process of the mixed gas passing through carbon powder C, some hydrocarbons were adsorbed by carbon powder C, and the hydrocarbon concentration in the mixed gas decreased.

[0017] Furthermore, the carbon powder A and carbon powder B in the device adsorb a small amount of hydrocarbons. In the desorption state, the mixed gas passing through carbon powder A and carbon powder B contains a low concentration of hydrocarbons. At this time, carbon powder C adsorbs a large amount of hydrocarbons during the desorption process. When the mixed gas passes through carbon powder C, carbon powder C releases hydrocarbons, and the hydrocarbon concentration in the mixed gas increases.

[0018] Furthermore, the carbon powder A and carbon powder B in the device adsorb a large amount of hydrocarbons. In the desorption state, the mixed gas passing through the carbon powder A and carbon powder B contains a high concentration of hydrocarbons. At this time, the carbon powder C adsorbs a large amount of hydrocarbons during the desorption process. The carbon powder C does not participate in the desorption at the first time, and the hydrocarbon concentration in the mixed gas decreases with the desorption process. At this time, the carbon powder C begins to participate in the desorption work, and some hydrocarbons are adsorbed by the carbon powder C, and the hydrocarbon concentration in the mixed gas decreases.

[0019] Furthermore, the hydrocarbon concentration in the mixed gas just meets the adsorption saturation of the carbon powder C, and the carbon powder C does not participate in the desorption work, and the hydrocarbon concentration in the mixed gas remains unchanged.

[0020] Compared with the prior art, the device and method for reducing the impact of exhaust gas desorption described in the present invention have the following beneficial effects:

[0021] The present invention describes a device and method for reducing the impact of exhaust gas desorption. This method involves adding a carbon powder with poor adsorption capacity to the desorption pathway of the canister system. This powder participates only in the desorption process and not the adsorption process, thereby reducing the rate of change in hydrocarbon concentration during the desorption process. The resulting gradual change in hydrocarbon concentration in the mixed gas during the desorption process, without significant fluctuations, effectively ensures engine combustion quality and reduces the impact of the desorption process on exhaust emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0023] Figure 1 This is a schematic diagram of the structure of a device for reducing the impact of exhaust gas desorption according to an embodiment of the present invention.

[0024] Description of reference numerals:

[0025] 1. Connecting chamber; 2. Adsorption chamber; 3. Desorption chamber; 4. Desorption partition; 5. Adsorption partition. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0027] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0028] A device for reducing the impact of exhaust desorption includes a desorption chamber 3, an adsorption chamber 2, and a connecting chamber 1; the desorption chamber 3 is connected to the connecting chamber 1, and the desorption chamber 3 is connected to the engine's intake manifold; the adsorption chamber 2 is connected to the connecting chamber 1, and the adsorption chamber 2 is connected to the atmospheric environment; the connecting chamber 1 is connected to the fuel tank; a solenoid valve is provided between the desorption chamber 3 and the intake manifold; different types of carbon powder are provided in the desorption chamber 3, the adsorption chamber 2, and the connecting chamber 1.

[0029] The carbon powder in the desorption chamber 3 is separated from the carbon powder in the connecting chamber 1 by a desorption partition 4, and the carbon powder in the adsorption chamber 2 is separated from the carbon powder in the connecting chamber 1 by an adsorption partition 5; the desorption partition 4 and the adsorption partition 5 are both mesh partitions that only isolate the flow of solids.

[0030] The side wall of the adsorption chamber 2 extends toward the inner side of the connecting chamber 1 to form an adsorption channel, and the side wall of the desorption chamber 3 extends toward the inner side of the connecting chamber 1 to form a desorption channel.

[0031] The adsorption capacity of the carbon powder in the connecting chamber 1 is higher than that in the desorption chamber 3. The adsorption capacity of the carbon powder in the adsorption chamber 2 is higher than that in the connecting chamber 1.

[0032] A compression spring and a compression baffle are provided in the connecting chamber 1; the compression spring presses the compression baffle, and the compression baffle presses the carbon powder in the connecting chamber 1. At the same time, the carbon powder in the connecting chamber 1 presses the desorption partition 4 and the adsorption partition 5, and the desorption partition 4 and the adsorption partition 5 respectively press the carbon powder in the desorption chamber 3 and the adsorption chamber 2.

[0033] The device has the following two working states:

[0034] Adsorption state: When the device is in the adsorption state, the hydrocarbon mixture in the fuel tank passes through connecting chamber 1, adsorption channel, and adsorption chamber 2 in sequence before entering the atmosphere. During this process, the carbon powder A in connecting chamber 1 and the carbon powder B in adsorption chamber 2 adsorb the hydrocarbons in the mixture. At the same time, the solenoid valve is closed, and under the influence of negative atmospheric pressure, the mixture does not pass through desorption chamber 3.

[0035] Desorption state: When the equipment is in the desorption state, the solenoid valve is opened, and under the influence of the negative pressure of the intake air at the engine end, the fresh air from the atmospheric environment passes through the adsorption chamber 2, the adsorption channel, the connecting chamber 1, the desorption channel, and the desorption chamber 3 in sequence and enters the engine combustion chamber; in the process of the fresh air entering the combustion chamber, the fresh air passes through the carbon powder A, the carbon powder B, and the carbon powder C in the desorption chamber 3, and desorbs hydrocarbons to form a mixed gas containing hydrocarbons; at the same time, under the influence of the negative pressure of the intake air at the engine end, the mixed gas containing hydrocarbons in the fuel tank passes through the connecting chamber 1, the desorption channel, and the desorption chamber 3 and enters the engine combustion chamber.

[0036] The carbon powder A and carbon powder B in the device adsorb a large amount of hydrocarbons. In the desorption state, the mixed gas passing through carbon powder A and carbon powder B contains a high concentration of hydrocarbons. At this time, carbon powder C does not adsorb too many hydrocarbons and still has good adsorption capacity. In the process of the mixed gas passing through carbon powder C, some hydrocarbons are adsorbed by carbon powder C, and the hydrocarbon concentration in the mixed gas decreases.

[0037] The carbon powder A and carbon powder B in the device adsorb a small amount of hydrocarbons. In the desorption state, the mixed gas passing through carbon powder A and carbon powder B contains a low concentration of hydrocarbons. At this time, carbon powder C adsorbs a large amount of hydrocarbons during the desorption process. When the mixed gas passes through carbon powder C, carbon powder C releases hydrocarbons, and the hydrocarbon concentration in the mixed gas increases.

[0038] The carbon powder A and carbon powder B in the device adsorb a large amount of hydrocarbons. In the desorption state, the mixed gas passing through carbon powder A and carbon powder B contains a high concentration of hydrocarbons. At this time, carbon powder C adsorbs a large amount of hydrocarbons during the desorption process. Carbon powder C does not participate in desorption at the first time, and the hydrocarbon concentration in the mixed gas decreases with the desorption process. At this time, carbon powder C begins to participate in the desorption work, and some hydrocarbons are adsorbed by carbon powder C, and the hydrocarbon concentration in the mixed gas decreases.

[0039] The hydrocarbon concentration in the mixed gas just meets the adsorption saturation of carbon powder C. Carbon powder C does not participate in the desorption work, and the hydrocarbon concentration in the mixed gas remains unchanged.

[0040] Those skilled in the art will appreciate that the units and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0041] In the several embodiments provided in this application, it should be understood that the disclosed methods and systems can be implemented in other ways. For example, the division of the units described above is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. The above-mentioned units may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiment of the present invention.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for reducing the impact of tail gas desorption, implemented by a device for reducing the impact of tail gas desorption, characterized in that: The device comprises a desorption chamber (3), an adsorption chamber (2), and a connecting chamber (1); The desorption chamber (3) is connected to the connecting chamber (1), and the desorption chamber (3) is connected to the intake manifold of the engine; the adsorption chamber (2) is connected to the connecting chamber (1), and the adsorption chamber (2) is connected to the atmospheric environment; the connecting chamber (1) is connected to the fuel tank; a solenoid valve is provided between the desorption chamber (3) and the intake manifold; Different types of carbon powder are respectively provided in the desorption chamber (3), the adsorption chamber (2), and the connecting chamber (1); The carbon powder in the desorption chamber (3) is separated from the carbon powder in the connecting chamber (1) by a desorption partition (4), and the carbon powder in the adsorption chamber (2) is separated from the carbon powder in the connecting chamber (1) by an adsorption partition (5); The desorption partition (4) and the adsorption partition (5) are both mesh partitions that only isolate the flow of solids; The side wall of the adsorption chamber (2) extends toward the inside of the connecting chamber (1) to form an adsorption channel, and the side wall of the desorption chamber (3) extends toward the inside of the connecting chamber (1) to form a desorption channel; The adsorption capacity of the carbon powder in the connecting chamber (1) is higher than the adsorption capacity of the carbon powder in the desorption chamber (3), and the adsorption capacity of the carbon powder in the adsorption chamber (2) is higher than the adsorption capacity of the carbon powder in the connecting chamber (1); A compression spring and a compression baffle are provided in the connecting chamber (1); the compression spring presses the compression baffle, and the compression baffle presses the carbon powder in the connecting chamber (1), and at the same time, the carbon powder in the connecting chamber (1) presses the desorption partition (4) and the adsorption partition (5), and the desorption partition (4) and the adsorption partition (5) respectively press the carbon powder in the desorption chamber (3) and the adsorption chamber (2); The device has the following two working states: Adsorption state: When the device is in the adsorption state, the mixed gas containing hydrocarbons in the fuel tank passes through the connecting chamber (1), the adsorption channel, and the adsorption chamber (2) in sequence and then enters the atmospheric environment; during the process of the mixed gas entering the atmospheric environment from the fuel tank, the carbon powder A in the connecting chamber (1) and the carbon powder B in the adsorption chamber (2) adsorb the hydrocarbons in the mixed gas; at the same time, the solenoid valve is in a closed state, and the mixed gas does not pass through the desorption chamber (3); Desorption state: When the device is in the desorption state, the solenoid valve is opened, and under the influence of the negative pressure of the engine intake, the fresh air from the atmospheric environment passes through the adsorption chamber (2), the adsorption channel, the connecting chamber (1), the desorption channel, the desorption chamber (3) in sequence, and then enters the engine combustion chamber; In the process of fresh air entering the combustion chamber, the fresh air passes through carbon powder B, carbon powder A, and carbon powder C in the desorption chamber (3), and desorbs hydrocarbons to form a mixed gas containing hydrocarbons; at the same time, under the influence of the negative pressure of the intake air at the engine end, the mixed gas containing hydrocarbons in the fuel tank enters the engine combustion chamber through the connecting chamber (1), the desorption channel, and the desorption chamber (3).

2. The method for reducing the impact of tail gas desorption according to claim 1, characterized in that: The carbon powder A and carbon powder B in the device adsorb a large amount of hydrocarbons. In the desorption state, the mixed gas passing through carbon powder A and carbon powder B contains a high concentration of hydrocarbons. At this time, carbon powder C does not adsorb too many hydrocarbons and still has good adsorption capacity. In the process of the mixed gas passing through carbon powder C, some hydrocarbons are adsorbed by carbon powder C, and the hydrocarbon concentration in the mixed gas decreases.

3. The method for reducing the impact of tail gas desorption according to claim 1, characterized in that: The carbon powder A and carbon powder B in the device adsorb a small amount of hydrocarbons. In the desorption state, the mixed gas passing through carbon powder A and carbon powder B contains a low concentration of hydrocarbons. At this time, carbon powder C adsorbs a large amount of hydrocarbons during the desorption process. When the mixed gas passes through carbon powder C, carbon powder C releases hydrocarbons, and the hydrocarbon concentration in the mixed gas increases.

4. The method for reducing the impact of tail gas desorption according to claim 1, characterized in that: The hydrocarbon concentration in the mixed gas just meets the adsorption saturation of carbon powder C. Carbon powder C does not participate in the desorption work, and the hydrocarbon concentration in the mixed gas remains unchanged.

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