Fuel cell tail gas collecting box for forklift and water and gas discharging control method of fuel cell tail gas collecting box

Abstract

The invention relates to the technical field of fuel cells, and discloses a fuel cell tail gas collecting box for a forklift and a water and gas discharging control method thereof.The fuel cell tail gas collecting box for the forklift comprises a box body used for storing liquid water and tail gas of a fuel cell system; the partition plate is arranged in the box body and can ascend and descend in the height direction of the box body, and the partition plate divides the box body into an air storage cavity and an exhaust cavity; the air inlet is connected with the air storage cavity; an air outlet; and the hydrogen discharge port is connected with the top of the gas storage cavity and is used for discharging hydrogen. The box body is divided into the gas storage cavity and the gas exhaust cavity through the partition plate, so that hydrogen in tail gas can be separated from other gases, it is ensured that the hydrogen cannot be directly discharged into the atmosphere, the forklift can work for a long time even in a closed environment, and through cooperation of the partition plate, the first liquid outlet and the second liquid outlet, the working efficiency is improved. And the forklift can conduct liquid drainage operation through different strategies, and the application scenes of the forklift are further increased.

Description

[Technical field]

[0001] The present invention relates to the technical field of fuel cells, and in particular to a fuel cell tail gas collection box for a forklift and a drainage and exhaust control method thereof. [Background technology]

[0002] Fuel cell forklifts are forklifts that use fuel cells as a power source and hydrogen as fuel. Fuel cell forklifts have significant advantages in terms of environmental protection, high efficiency, safety, long life and applicability, and are one of the development trends of the forklift industry in the future. With the continuous advancement of technology and the acceleration of industrialization, fuel cell forklifts are expected to be widely used in more fields.

[0003] At present, the tail exhaust gas of fuel cell forklifts is directly discharged. The tail exhaust gas contains hydrogen. If in a closed environment, the hydrogen is very likely to accumulate and explode. Therefore, current fuel cell forklifts are mainly used in open environments to ensure that the discharged hydrogen can diffuse into the atmosphere as soon as possible and hydrogen accumulation will not occur. As a result, the use environment of existing fuel cell forklifts is not conducive to the vigorous promotion of fuel cell forklifts. [Summary of the invention]

[0004] The present invention aims to solve the above problems and provides a fuel cell exhaust gas collection box for a forklift and a drainage and exhaust control method thereof, so as to solve the problem that the existing fuel cell forklift has a limited use environment due to the exhaust gas containing hydrogen.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A fuel cell exhaust gas collection box for a forklift, comprising:

[0007] A tank for storing liquid water and exhaust gas from the fuel cell system;

[0008] A partition plate is disposed in the box body and can be lifted and lowered in the height direction of the box body, and the partition plate divides the box body into an air storage chamber and an exhaust chamber;

[0009] An air inlet, connected to the air storage chamber, for introducing tail gas from the fuel cell system;

[0010] An air outlet, connected to the exhaust chamber, for discharging oxygen and nitrogen;

[0011] A hydrogen discharge port, connected to the top of the gas storage chamber, for discharging hydrogen;

[0012] A first liquid outlet, connected to the side wall of the box body, and used to control the water level of the liquid water in the box body;

[0013] The second liquid outlet is connected to the bottom of the box body and is used to drain the liquid water in the box body.

[0014] Preferably, the volume of the air storage chamber is greater than the volume of the exhaust chamber.

[0015] Preferably, it also includes:

[0016] A silencer pipe connected to the end of the air inlet;

[0017] The silencer pipe is provided with a plurality of openings for silencer.

[0018] Preferably, it also includes:

[0019] a baffle plate, arranged between the partition plate and the muffler pipe;

[0020] One end of the baffle is connected to the inner wall of the box body, and the other end extends vertically downward;

[0021] The straight-line distance between the extended end of the baffle and the bottom of the box body is smaller than the straight-line distance between the bottom end of the muffler pipe and the bottom of the box body;

[0022] The baffle is a mesh structure.

[0023] Preferably, it also includes:

[0024] A liquid guide plate is arranged in the exhaust cavity, and two ends of the liquid guide plate are respectively connected to the top and the side wall of the box body;

[0025] The liquid guide plate is a mesh structure;

[0026] The horizontal projection area of ​​the liquid guide plate on the box body covers the air outlet.

[0027] A method for controlling drainage and exhaust gas, applied to the exhaust gas collection box, is characterized by comprising the following control steps:

[0028] Obtaining the volume ratio of the air storage chamber and the exhaust chamber;

[0029] If the volume ratio of the gas storage chamber to the exhaust chamber is greater than 2:1, the first strategy is selected to control the drainage and exhaust of the exhaust gas collection box;

[0030] If the volume ratio of the gas storage chamber to the exhaust chamber is less than 2:1, the second strategy is selected to control the drainage and exhaust of the exhaust gas collection box;

[0031] Among them, the first strategy completes drainage and exhaust control based on the liquid level height in the exhaust collection box;

[0032] The second strategy completes drainage and exhaust control based on the air pressure in the air storage chamber.

[0033] Preferably, the first strategy includes the following control steps:

[0034] Adjust the partition plate so that the bottom end of the partition plate is tangent to the bottom of the box;

[0035] Open the air inlet and outlet, and close the hydrogen outlet and the second liquid outlet;

[0036] Setting a first preset height, wherein the first preset height is consistent with the height of the lowest end of the first liquid outlet;

[0037] When the liquid level in the air storage cavity rises from 0 to the first preset height, the bottom end of the partition plate always remains tangent to the liquid surface;

[0038] When the liquid level in the gas storage cavity rises to a first preset height, the first liquid outlet is opened;

[0039] When the hydrogen concentration in the gas storage chamber reaches a first preset concentration, the gas inlet is closed, the hydrogen outlet is opened, and the hydrogen is discharged;

[0040] When the hydrogen concentration in the gas storage cavity reaches a second preset concentration, the hydrogen discharge port, the gas outlet and the first liquid outlet are closed, the second liquid outlet is opened, and the partition plate is adjusted to keep the bottom end of the partition plate at the first preset height position unchanged;

[0041] When the liquid level drops to 0, close the second liquid outlet, adjust the partition plate so that the bottom end of the partition plate is tangent to the bottom of the box body, open the air inlet and outlet, and complete the drainage and exhaust control of the exhaust gas collection box.

[0042] Preferably, the first strategy further includes the following control steps:

[0043] Adjust the partition plate so that the bottom end of the partition plate is tangent to the bottom of the box;

[0044] Open the air inlet and outlet, and close the hydrogen outlet and the second liquid outlet;

[0045] Adjust the partition plate so that the bottom end of the partition plate is always tangent to the liquid surface;

[0046] Setting a first preset height, wherein the first preset height is consistent with the height of the lowest end of the first liquid outlet;

[0047] When the liquid level in the gas storage cavity rises to a first preset height, the first liquid outlet is opened;

[0048] When the hydrogen concentration in the gas storage chamber reaches a first preset concentration, the gas inlet is closed, the hydrogen outlet is opened, and the hydrogen is discharged;

[0049] When the hydrogen concentration in the gas storage cavity reaches a second preset concentration, the hydrogen discharge port is closed and the second liquid outlet is opened;

[0050] When the liquid level drops to 0, the second liquid outlet is closed to complete the drainage and exhaust control of the tail gas collection box.

[0051] Preferably, the second strategy includes the following control steps:

[0052] Adjust the partition plate so that the bottom end of the partition plate is tangent to the bottom of the box;

[0053] Open the air inlet and outlet, and close the hydrogen outlet and the second liquid outlet;

[0054] When the air pressure in the air storage chamber reaches a first preset air pressure value, the partition plate is adjusted so that the bottom end of the partition plate remains tangent to the liquid surface;

[0055] When the air pressure in the air storage chamber reaches the first preset air pressure value again, the air inlet is closed, the hydrogen outlet is opened, and the hydrogen is discharged;

[0056] When the hydrogen concentration in the gas storage chamber reaches a second preset concentration, the hydrogen discharge port is closed, the second liquid discharge port is opened, and the bottom end of the partition plate is kept at the second preset height position unchanged;

[0057] When the liquid level drops to 0, the second drain port is closed, and the partition plate is adjusted so that the bottom end of the partition plate is tangent to the bottom of the box body, thereby completing the drainage and exhaust control of the exhaust gas collection box.

[0058] Preferably, when the air pressure in the air storage chamber reaches the first preset air pressure value again, the hydrogen concentration in the air storage chamber is less than the first preset concentration.

[0059] The contribution of the present invention is that the present invention divides the box into an air storage chamber and an exhaust chamber through a partition plate, so that the hydrogen in the exhaust gas can be separated from other gases, ensuring that the hydrogen will not be directly discharged into the atmosphere, so that the forklift can work for a long time even in a closed environment, and through the cooperation of the partition plate, the first liquid outlet and the second liquid outlet, the forklift can perform liquid discharge operations through different strategies, further increasing the applicable scenarios of the forklift.

Brief Description of the Drawings

[0060] Figure 1 Schematic diagram of the internal structure of the tail gas collection device of the present invention;

[0061] Figure 2 Schematic diagram of the drainage and exhaust flow of the tail gas collection device of the present invention;

[0062] Figure 3 is a schematic flow chart of the first strategy of the present invention;

[0063] Figure 4 is a flow chart of the first strategy in the second embodiment of the present invention;

[0064] Figure 5 is a schematic flow chart of the second strategy of the present invention;

[0065] Figure 6 is a schematic flow chart of the third strategy in the third embodiment of the present invention;

[0066] Figure 7 is a schematic diagram of the relationship between power and the descending height of the partition plate in the third embodiment of the present invention;

[0067] Among them: box body 10, gas storage chamber 11, exhaust chamber 12, partition plate 20, air inlet 30, air outlet 40, hydrogen exhaust port 50, first liquid outlet 60, second liquid outlet 70, silencer 80, opening 81, baffle 90, liquid guide plate 1a. [Specific implementation method]

[0068] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The drawings provide embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0069] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing the embodiments of the present invention and are not intended to limit this application.

[0070] It is understood that the terms "first", "second", etc. used in this application can be used in this article to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element, or connected to the other element through an intermediate element. In addition, the "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if there is a transmission of electrical signals or data between the connected objects.

[0071] When used herein, the singular forms "a", "a person" and "the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0072] Example 1

[0073] like Figure 1 As shown, a fuel cell exhaust gas collection box for a forklift includes:

[0074] The box 10 is used to store liquid water and exhaust gas of the fuel cell system;

[0075] The partition plate 20 is disposed in the box body 10 and can be lifted and lowered in the height direction of the box body 10. The partition plate 20 divides the box body 10 into an air storage chamber 11 and an exhaust chamber 12.

[0076] An air inlet 30 connected to the air storage chamber 11 and used for introducing tail gas from the fuel cell system;

[0077] An air outlet 40 connected to the exhaust chamber 12 for discharging oxygen and nitrogen;

[0078] A hydrogen discharge port 50 connected to the top of the gas storage chamber 11 for discharging hydrogen;

[0079] A first liquid outlet 60 connected to the side wall of the box body 10 and used to control the water level of the liquid water in the box body 10;

[0080] The second liquid outlet 70 is connected to the bottom of the box body 10 and is used to drain the liquid water in the box body 10 .

[0081] To further illustrate this embodiment, the partition plate 20 can be lifted and lowered in the vertical direction (motor driven or elastically connected), and when the maximum downward movement is reached, it is tangent to the bottom of the box body 10. The partition plate 20 divides the box body 10 into a gas storage chamber 11 and an exhaust chamber 12. The gas storage chamber 11 is used to collect and store tail gas, which contains hydrogen, nitrogen, oxygen and water vapor. In many cases, hydrogen cannot be discharged at will, so it is necessary to collect hydrogen through the gas storage chamber 11. To further illustrate, hydrogen, nitrogen, oxygen and water vapor are Water vapor will gradually stratify in the gas storage chamber 11, and accumulate at the bottom of the box body 10 after liquefaction. Hydrogen, which has the lightest mass, will accumulate at the top of the gas storage chamber 11. The gas storage chamber 11 contains hydrogen, nitrogen and oxygen from top to bottom. The hydrogen accumulated on the top is guided to the ejector through the hydrogen discharge port 50 for recycling, and the nitrogen and oxygen are discharged to the outside from the gas outlet 40 under the control of the partition plate 20, so that the exhaust gas emitted by the forklift does not contain hydrogen, which greatly increases the safety performance of the forklift and allows the forklift to be used in more occasions.

[0082] The first liquid outlet 60 can be used to discharge the liquid water in the box 10 (mainly obtained by liquefying the water vapor in the exhaust gas), so as to control the height of the liquid level in the box 10 (the water vapor entering the gas storage chamber 11 will be liquefied, and will be discharged from the first liquid outlet 60 after liquefaction). The second liquid outlet 70 cooperates with the first strategy or the second strategy to discharge the liquid water in the box 10. Specifically, the first liquid outlet 60 will discharge liquid water anytime and anywhere, so it is suitable for the forklift to use the first liquid outlet 60 to drain liquid in a site without drainage requirements (i.e., the first strategy). If the site has high requirements for humidity, the first strategy cannot be used to drain the exhaust gas collection box. At this time, the second strategy must be used for drainage, that is, all the accumulated water in the box 10 is discharged at one time through the second liquid outlet 70 (to a designated location for discharge). By setting the first liquid outlet 60 and the second liquid outlet 70 and cooperating with the first strategy and the second strategy to discharge the liquid water in the box 10, the forklift can work normally in different working environments.

[0083] The present invention divides the box body 10 into an air storage chamber 11 and an exhaust chamber 12 through a partition plate 20, so that hydrogen in the exhaust gas can be separated from other gases, ensuring that hydrogen is not directly discharged into the atmosphere, so that the forklift can work for a long time even in a closed environment. Through the cooperation of the partition plate 20, the first liquid outlet 60 and the second liquid outlet 70, the forklift can perform liquid discharge operations through different strategies, further increasing the applicable scenarios of the forklift.

[0084] To further explain, the volume of the air storage chamber 11 is greater than the volume of the exhaust chamber 12 .

[0085] The volume of the air storage chamber 11 is larger than that of the exhaust chamber 12 , so that the box 10 can collect more exhaust gas for a long time without draining or exhausting the gas, thereby increasing the effective working time of the forklift. Specifically, the volume of the air storage chamber 11 is generally 2-4 times that of the exhaust chamber 12 .

[0086] Further description of this embodiment also includes:

[0087] A silencer pipe 80 connected to the end of the air inlet 30;

[0088] The silencer pipe 80 is provided with a plurality of openings 81 for silencer.

[0089] After the exhaust gas from the air inlet 30 enters the box body 10, it first flows through the silencer 80. The silencer 80 is a straight tubular body. There are several openings 81 distributed on the silencer 80. On the one hand, it plays a role of silencing. On the other hand, it also plays a role of slowing down the flow rate of the tail exhaust gas, so that a part of the gas diffuses from the surrounding of the silencer 80 into the gas storage chamber 11, reducing the impact of the gas (undiffused gas) on the baffle 90 and the partition plate 20 (under high power, the flow rate of the tail exhaust gas is large and the flow rate is fast, with a strong impact force).

[0090] Further description of this embodiment also includes:

[0091] a baffle 90 disposed between the partition plate 20 and the muffler 80;

[0092] One end of the baffle 90 is connected to the inner wall of the box body 10, and the other end extends vertically downward;

[0093] The straight-line distance between the extended end of the baffle 90 and the bottom of the box 10 is smaller than the straight-line distance between the bottom end of the muffler 80 and the bottom of the box 10;

[0094] The baffle 90 is a mesh structure.

[0095] The baffle 90 is provided to further slow down the impact of the airflow, minimize the impact of the exhaust gas on the partition 20, and ensure that the partition 20 can take off and land normally. One end of the baffle 90 is connected to the inner wall of the box 10, and the other end extends vertically downward to ensure that the baffle 90 is vertically arranged with the muffler to slow down the airflow from the muffler 80 as much as possible. The straight-line distance between the extended end of the baffle 90 and the bottom of the box 10 is less than the straight-line distance between the bottom end of the muffler 80 and the bottom of the box 10, ensuring that the baffle 90 can fully cover the muffler 80, and ensure that the gas flowing out of the muffler 80 (not flowing out of the opening 81 on the muffler 80) can be completely intercepted by the baffle 90. The baffle 90 is a mesh structure, which can greatly slow down the flow rate of the gas, so that the gas diffuses in the gas storage chamber 11. On the other hand, the mesh structure can filter the water vapor in the exhaust gas, so that the water vapor condenses on the mesh structure of the baffle 90, so that the hydrogen, nitrogen and oxygen in the exhaust gas are stratified as soon as possible.

[0096] Further description of this embodiment also includes:

[0097] A liquid guide plate 1a is disposed in the exhaust cavity 12, and two ends of the liquid guide plate 1a are respectively connected to the top and the side wall of the box body 10;

[0098] The liquid guide plate 1a is a mesh structure;

[0099] The horizontal projection area of ​​the liquid guide plate 1 a on the box body 10 covers the air outlet 40 .

[0100] To further illustrate this embodiment, the setting of the liquid guide plate 1a can filter the gas in the exhaust chamber 12, remove water vapor in the gas, and ensure that the humidity of the gas discharged from the air outlet 40 is not high and meets the exhaust requirements. Specifically, the liquid guide plate 1a is arranged in the exhaust chamber 12 at a 45° angle (the two ends of the liquid guide plate 1a are respectively connected to the top and side walls of the box body 10). The inclined setting increases the contact probability of the exhaust gas and the liquid guide plate 1a. The horizontal projection area of ​​the liquid guide plate 1a on the box body 10 covers the air outlet 40, ensuring that all gases discharged from the air outlet 40 must be filtered by the liquid guide plate 1a, and the discharged gas is in a dry state. According to the humidity requirements of the working environment, multiple liquid guide plates 1a can be arranged in the exhaust chamber 12 to ensure that the discharged gas is dry enough to meet the emission standards.

[0101] like Figure 2 As shown, this embodiment also discloses a drainage and exhaust control method, which is applied to the exhaust gas collection box, and includes the following control steps:

[0102] Obtaining the volume ratio of the air storage chamber 11 and the exhaust chamber 12;

[0103] If the volume ratio of the gas storage chamber 11 to the exhaust chamber 12 is greater than 2:1, the first strategy is selected to control the drainage and exhaust of the exhaust gas collection box;

[0104] The first strategy completes drainage and exhaust control based on the liquid level in the exhaust collection box;

[0105] like Figure 3 As shown, specifically, the first strategy includes the following control steps:

[0106] Adjust the partition plate 20 so that the bottom end of the partition plate 20 is tangent to the bottom of the box body 10;

[0107] Open the air inlet 30 and the air outlet 40, and close the hydrogen outlet 50 and the second liquid outlet 70;

[0108] Setting a first preset height, the first preset height being consistent with the height of the lowest end of the first liquid outlet 60;

[0109] During the process of the liquid level in the air storage chamber 11 rising from 0 to the first preset height, the bottom end of the partition plate 20 always maintains a tangent state with the liquid surface;

[0110] When the liquid level in the gas storage chamber 11 rises to a first preset height, the first liquid outlet 60 is opened;

[0111] When the hydrogen concentration in the gas storage chamber 11 reaches a first preset concentration, the gas inlet 30 is closed, the hydrogen outlet 50 is opened, and the hydrogen is discharged;

[0112] When the hydrogen concentration in the gas storage chamber 11 reaches the second preset concentration, the hydrogen discharge port 50, the gas outlet 40 and the first liquid outlet 60 are closed, the second liquid outlet 70 is opened, and the bottom end of the partition plate 20 is kept at the first preset height position unchanged;

[0113] When the liquid level drops to 0, the second liquid outlet 70 is closed, the partition plate 20 is adjusted so that the bottom end of the partition plate 20 is tangent to the bottom of the box body 10, and the air inlet 30 and the air outlet 40 are opened to complete the drainage and exhaust control of the exhaust gas collection box.

[0114] To further explain this embodiment, the first strategy is applicable to an exhaust gas collection box with a small gas storage chamber 11 and no drainage requirements for the workplace (a forklift can discharge liquid water anywhere). Specifically, in the initial state of the exhaust gas collection box, there is no liquid water in the box body 10, and in order to prevent the exhaust gas discharged into the gas storage chamber 11 from the air inlet 30 from being directly discharged from the exhaust chamber 12 (containing hydrogen), the partition plate 20 is first adjusted to a state tangent to the bottom of the box body 10 to ensure that the exhaust gas entering the box body 10 cannot enter the exhaust chamber 12. When the forklift starts working, the exhaust gas will enter the exhaust chamber through the air inlet 30. Since the exhaust gas contains hydrogen, oxygen, nitrogen and water vapor, under the action of the silencer 80 and the baffle 90, the water vapor will liquefy at the bottom of the gas storage chamber 11. In the process of the liquid level in the gas storage chamber 11 rising from 0 to the first preset height, the bottom end of the partition plate 20 always maintains a tangent state with the liquid surface (to ensure that hydrogen does not enter the exhaust chamber 12). To further illustrate, due to the difference in molecular weight, hydrogen, oxygen and nitrogen will gradually be stratified in the gas storage chamber 11. The uppermost layer of the gas storage chamber 11 is hydrogen, followed by nitrogen and oxygen. As the upper hydrogen accumulates, the nitrogen and oxygen in the lower layer will be squeezed. However, since the first liquid outlet 60 is not opened at this time, the gas will be accumulated in layers in the gas storage chamber 11. When the liquid level reaches the first preset height, the first liquid outlet 60 is opened, and the newly liquefied liquid water will be discharged from the first liquid outlet 60. At this time, the height of the liquid level in the box body 10 will not rise any more, and the gas level will always be kept at a constant level. The first liquid outlet 60 is opened, and the oxygen and nitrogen in the bottom layer bypass the bottom end of the partition plate 20 and enter the exhaust chamber 12 under the squeeze of hydrogen, and are discharged to the outside atmosphere from the gas outlet 40 or the first liquid outlet 60. The hydrogen concentration in the gas storage chamber 11 continues to rise. When the hydrogen concentration in the gas storage chamber 11 reaches the first preset concentration (the hydrogen discharge concentration is determined according to the volume of the gas storage chamber 11, and the second preset concentration is the same), the gas inlet 30 is closed to avoid excessive pressure in the gas storage chamber 11, and the hydrogen discharge port 50 is opened to guide the hydrogen in the gas storage chamber 11 to the ejector for recycling. When the hydrogen concentration in the gas storage chamber 11 reaches the second preset concentration, the hydrogen concentration in the gas storage chamber 11 is low at this time and is not suitable for continued discharge, so the hydrogen discharge port 50 is closed. Port 50. Since there is a large amount of liquid water in the box body 10, the liquid water occupies the storage space of the gas. The liquid water in the box body 10 needs to be discharged to the outside to prepare for the next storage of tail gas. At this time, the gas outlet 40 and the first liquid outlet 60 are closed, and the second liquid outlet 70 is opened. The liquid water flows to the outside from the first liquid outlet 60. While discharging the liquid water, the bottom end of the partition plate 20 is kept at the first preset height position unchanged (reducing the movement frequency of the partition plate 20, slowing down the aging of the partition plate 20, and ensuring the movement accuracy of the partition plate 20). When the liquid level drops, a small amount of nitrogen and oxygen in the bottom layer will also be mixed and discharged to the outside through the second liquid outlet 70 (and some of the gas containing hydrogen will be retained in the exhaust chamber 12). When the liquid level drops to 0,The second liquid outlet 70 is closed to complete the liquid discharge process. At this time, the partition plate 20 is adjusted so that the bottom of the partition plate 20 is tangent to the bottom of the box body 10, and the air inlet 30 and the air outlet 40 are reopened, thereby completing the drainage and exhaust control of the exhaust gas collection box (first strategy control).

[0115] To further illustrate this embodiment, Figure 5 As shown, the second strategy in this embodiment (drainage and exhaust control based on the air pressure in the air storage chamber 11) is suitable for forklifts in places where the water cannot be drained at will (for example, environments with strict requirements on humidity or environments prone to freezing in northern winter). Compared with the first strategy, the second strategy will not have intermittent liquid water discharged to the ground during the process of collecting exhaust gas (only discharged through the second liquid outlet 70), and the accumulated water in the exhaust gas collection box is uniformly discharged at a designated location.

[0116] Specifically, the second strategy includes the following control steps:

[0117] Adjust the partition plate 20 so that the bottom end of the partition plate 20 is tangent to the bottom of the box body 10 (to isolate the gas storage chamber 11 and the exhaust chamber 12, and prevent the hydrogen in the gas storage chamber 11 from escaping into the exhaust chamber 12);

[0118] Open the air inlet 30 and the air outlet 40, and close the hydrogen outlet 50 and the second liquid outlet 70;

[0119] When the air pressure in the air storage chamber 11 reaches a first preset air pressure value, the partition plate 20 is adjusted so that the bottom end of the partition plate 20 remains tangent to the liquid surface;

[0120] Further explanation, since the partition plate 20 has always been tangent to the bottom of the box body 10 in the early stage, all the exhaust gas entering the box body 10 is accumulated in the air storage chamber 11, causing the air pressure in the air storage chamber 11 to rise rapidly. When the air pressure in the air storage chamber 11 reaches the critical pressure value (that is, the first preset air pressure value, which is determined according to the volume of the air storage chamber 11), the partition plate 20 is adjusted so that the partition plate 20 is lifted upward to a height position tangent to the liquid surface. At this time, part of the liquid water enters the exhaust chamber 12, causing the space in the air storage chamber 11 to become larger, and the air pressure in the air storage chamber 11 is reduced, so that the exhaust gas can continue to be collected.

[0121] When the air pressure in the gas storage chamber 11 reaches the first preset air pressure value again (the hydrogen concentration has not reached the first preset concentration, because the first liquid outlet 60 is in a closed state, the oxygen and nitrogen at the bottom cannot be squeezed to the outside, resulting in the hydrogen concentration in the gas storage chamber 11 not reaching the first preset concentration), the air inlet 30 is closed, the hydrogen outlet 50 is opened, and the hydrogen is discharged;

[0122] When the hydrogen concentration in the gas storage chamber 11 reaches the second preset concentration, the hydrogen discharge port 50 is closed and the second liquid discharge port is opened (whether the partition plate 20 changes with the liquid level depends on the working environment of the forklift. If it works in a closed environment, the bottom end of the partition plate 20 is kept tangent to the liquid surface. If it works in an open environment, the partition plate 20 can be kept at the second preset height position unchanged to reduce the movement of the partition plate 20 and delay the aging of the partition plate 20);

[0123] When the liquid level drops to 0, close the second drain port and adjust the partition plate 20 so that the bottom end of the partition plate 20 is tangent to the bottom of the box body 10 (regardless of the movement mode adopted by the partition plate 20, it is necessary to ensure that the bottom end of the partition plate 20 is tangent to the bottom of the box body 10 after drainage to ensure that hydrogen will not leak into the exhaust chamber 12 when the exhaust gas is subsequently introduced), thereby completing the drainage and exhaust control of the exhaust gas collection box.

[0124] Example 2

[0125] like Figure 4 As shown, in another embodiment of the present invention, considering that in the process of draining water in Example 1, part of the hydrogen will be retained in the exhaust chamber 12, when the gas outlet 40 is reopened, the retained hydrogen will be discharged to the environment. If the forklift works in a tunnel or a closed environment, hydrogen will accumulate on the top of the closed environment, causing the risk of explosion. Therefore, this embodiment adjusts Example 1 so that no hydrogen will be discharged to the environment in the exhaust gas collection box during exhaust or drainage. Specifically, Example 1 includes the following control steps:

[0126] Adjust the partition plate 20 so that the bottom end of the partition plate 20 is tangent to the bottom of the box body 10;

[0127] Open the air inlet 30 and the air outlet 40, and close the hydrogen outlet 50 and the second liquid outlet 70;

[0128] Adjust the partition plate 20 so that the bottom end of the partition plate 20 is always tangent to the liquid surface;

[0129] Setting a first preset height, the first preset height being consistent with the height of the lowest end of the first liquid outlet 60;

[0130] When the liquid level in the gas storage chamber 11 rises to a first preset height, the first liquid outlet 60 is opened;

[0131] When the hydrogen concentration in the gas storage chamber 11 reaches a first preset concentration, the gas inlet 30 is closed, the hydrogen outlet 50 is opened, and the hydrogen is discharged;

[0132] When the hydrogen concentration in the gas storage chamber 11 reaches a second preset concentration, the hydrogen discharge port 50 is closed and the second liquid outlet 70 is opened;

[0133] When the liquid level drops to 0, the second liquid outlet 70 is closed to complete the drainage and exhaust control of the tail gas collection box.

[0134] Compared with Example 1, the partition plate 20 in this embodiment remains tangent to the liquid surface regardless of whether it is during drainage or exhaust. That is, as the liquid level changes (increases or decreases), the partition plate 20 also changes with the liquid level, ensuring that no hydrogen will be retained in the exhaust chamber 12 during drainage.

[0135] Specifically, the exhaust method of this embodiment is consistent with that of Embodiment 1, and both of them are to guide the hydrogen at the top of the gas storage chamber 11 to the ejector for recycling by opening the hydrogen exhaust port 50. After the hydrogen is exhausted, this embodiment does not need to additionally close the first liquid outlet 60 and the gas outlet 40. Since the bottom end of the partition plate 20 always remains tangent to the liquid surface, even in the process of liquid level dropping, hydrogen will not overflow into the exhaust chamber 12, which reduces the control of the valve and increases the safety of the exhaust gas. It is suitable for closed occasions (such as factories, tunnels and other places) to ensure that hydrogen accumulation does not occur.

[0136] Example 3

[0137] like Figure 6 As shown, this embodiment discloses a drainage and exhaust control method, which is selectively adjusted according to the power of the forklift and is suitable for open sites (non-enclosed environments, where low-concentration hydrogen can be appropriately discharged). Specifically, this embodiment includes the following control steps:

[0138] Obtain the operating power of the forklift and determine the operating status of the forklift;

[0139] Among them, the operating state of the forklift includes: low-power operating state and high-power operating state;

[0140] Set up the third and fourth strategies;

[0141] Among them, the third strategy is to adjust the lifting of the partition plate 20 based on the operating power of the forklift;

[0142] The fourth strategy is to adjust the separation plate 20 up and down based on the liquid level and hydrogen concentration in the gas storage chamber 11;

[0143] When the forklift is in low-power operation, the third strategy is selected to control the exhaust gas collection box;

[0144] When the forklift is in a high-power operation state, the fourth strategy is selected to control the exhaust gas collection box.

[0145] To further illustrate this embodiment, Figure 7 As shown, the third strategy includes the following steps:

[0146] Get the low power range in which the forklift operates;

[0147] Divide the low power range into equal power to obtain p intervals;

[0148] The p intervals correspond to different descending heights of the partition plate 20 respectively;

[0149] In the low power range, the operating power of the forklift is proportional to the descending height of the partition plate 20 .

[0150] For example, the low power range of a 10t forklift is 0-9kw. The low power range of the forklift is divided into p=3 intervals of equal power, namely 0-3kw, 3kw-6kw, and 6kw-9kw. The height position of the partition plate 20 corresponding to each interval is different. For example, the lowering height of the partition plate 20 corresponding to the 0-3kw interval is 15cm (the lowering height is adjusted based on the minimum lowering height of the partition plate 20, 0. When the lowering height of the partition plate 20 is 0, the bottom end of the partition plate 20 and the lowest point of the air inlet 30 are at the same level), and the lowering height of the partition plate 20 corresponding to the 3kw- The descending height of the partition plate 20 corresponding to the 6kw interval is 30cm, and the descending height of the partition plate 20 corresponding to the 6kw-9kw interval is 45cm. The higher the height of the partition plate 20 descends, the closer the distance between the partition plate 20 and the bottom of the box body 10 is. Since the higher the power of the forklift, the higher the hydrogen content in the exhaust gas, and the greater the flow rate and flow velocity of the exhaust gas, the greater the probability of hydrogen flowing into the exhaust chamber 12 from the bottom of the partition plate 20. Therefore, in this embodiment, the power of the forklift operation and the descending height of the partition plate 20 are set to be proportional to each other to prevent a large amount of hydrogen from leaking from the bottom of the partition plate 20 into the exhaust chamber 12.

[0151] To further illustrate this embodiment, the third strategy also includes the following control steps:

[0152] When the end of the partition plate 20 close to the bottom of the box body 10 (i.e., the bottom end of the partition plate 20) is not in contact with the liquid surface in the box body 10, the air inlet 30 and the air outlet 40 are both in an open state, and the hydrogen discharge port 50 and the second liquid discharge port are both in a closed state;

[0153] When one end of the partition plate 20 close to the bottom of the box body 10 contacts the liquid surface in the box body 10, the following control steps are included:

[0154] Keep the air inlet 30 and the air outlet 40 in an open state, and open the second liquid discharge port;

[0155] When the liquid level in the box 10 is 0 (nitrogen and oxygen are basically discharged), the air inlet 30, the air outlet 40 and the second liquid discharge port are closed, and the hydrogen discharge port 50 is opened.

[0156] To further illustrate this embodiment, when the forklift is in the power range of 0-3kw, due to the low power of the forklift, the exhaust gas flow entering the air storage chamber 11 through the air inlet 30 is small and the flow rate is slow, hydrogen will accumulate at the top of the air storage chamber 11, and nitrogen and oxygen will flow into the exhaust chamber 12 through the space below the partition plate 20 (the partition plate 20 is lowered by 45cm) and are discharged to the outside atmosphere through the air outlet 40. As the exhaust gas continues to flow into the box body 10, liquid water will accumulate at the bottom of the box body 10, and the liquid level of the liquid water will gradually increase with the passage of time. When the bottom end of the partition plate 20 contacts the liquid water, it means that the hydrogen in the air storage chamber 11 has accumulated to a certain extent (the corresponding hydrogen accumulation amount in the air storage chamber 11 at different heights has been tested in advance, and the height can be set according to the experimental data table). At this time, drainage and exhaust can be performed separately according to the third strategy.

[0157] When the forklift changes load in the low power range, the power may increase or decrease. The 3kw-6kw range is used as an example here. When the forklift power changes from the 3kw-6kw range to the 6kw-9kw range, the partition plate 20 moves downward. If the partition plate 20 does not contact the liquid surface when it is lowered to the specified height, the working state of the water collecting tank in the 3kw-6kw range is maintained (that is, the air inlet 30, the air outlet 40, the hydrogen discharge port 50 and the second liquid discharge port are all maintained in the current state) until the bottom end of the partition plate 20 contacts the rising liquid surface, and the third strategy is used to discharge the gas and water in the water collecting tank separately. If the partition plate 20 directly contacts the liquid surface when it is lowered to the specified height, the above-mentioned third strategy is immediately used to discharge the gas and water in the water collecting tank separately.

[0158] When the forklift power changes from the 3kw-6kw range to the 0-3kw range, since the partition plate 20 is lifted upward at this time, the distance between the partition plate 20 and the liquid level at the bottom of the box body 10 increases, it is sufficient to maintain the working state of the water collecting tank in the 3kw-6kw range until the bottom end of the partition plate 20 contacts the rising liquid level, and the third strategy is used to discharge the gas and water in the water collecting tank separately.

[0159] To further illustrate this embodiment, the fourth strategy includes the following control steps:

[0160] Setting a first liquid level threshold, a second liquid level threshold, a hydrogen concentration threshold and a third preset height (set according to factors such as the volume of the box 10, the load power, and the exhaust gas flow rate);

[0161] The partition plate 20 is adjusted to the maximum descending height (at this time, the bottom end of the partition plate 20 is tangent to the bottom of the box body 10);

[0162] When the liquid level in the box body 10 does not reach the first liquid level threshold, the air inlet 30 and the air outlet 40 are both in an open state, and the hydrogen discharge port 50 and the second liquid discharge port are both in a closed state;

[0163] When the liquid level in the box body 10 reaches the first liquid level threshold, the second liquid discharge port is opened and the air inlet 30 is closed;

[0164] When the liquid level in the tank 10 drops to the second liquid level threshold, the partition plate 20 is lifted upward to a third preset height and the hydrogen discharge port 50 is opened;

[0165] When the hydrogen concentration decreases to a hydrogen concentration threshold, the partition plate 20 is adjusted to a maximum descending height, the second liquid discharge port and the hydrogen discharge port 50 are closed, and the gas inlet 30 is opened.

[0166] When the forklift is in a high-power state, the exhaust gas flow is large and the flow rate is fast. In order to prevent the exhaust gas from entering the exhaust chamber 12 through the bottom of the partition plate 20, the partition plate 20 is directly adjusted to the maximum descending height, that is, the bottom end of the partition plate 20 is kept tangent to the box body 10. At this time, the exhaust gas can only stay in the gas storage chamber 11, and the water vapor is liquefied and accumulated at the bottom of the gas storage chamber 11. When the liquid level reaches the first liquid level threshold (the first liquid level threshold is higher than the second liquid level threshold), it means that the hydrogen in the gas storage chamber 11 needs to be discharged. However, since the air pressure in the gas storage chamber 11 is relatively high at this time, in order to prevent the movement of the partition plate 20 from being obstructed, the second drain port is first opened to allow part of the liquid water to be discharged from the gas storage chamber 11, thereby reducing the pressure in the gas storage chamber 11. When the liquid level drops to the second liquid level threshold, the pressure in the gas storage chamber 11 It will not affect the vertical movement of the partition plate 20, so it is lifted up to the third preset height, and the hydrogen discharge port 50 is opened at the same time. The oxygen and nitrogen above the liquid surface are squeezed into the exhaust chamber 12 through the bottom end of the partition plate 20 under the pressure of the top hydrogen, and discharged to the external environment through the gas outlet 40. The hydrogen at the top of the gas storage chamber 11 is transported to the ejector through the hydrogen discharge port 50. When the hydrogen concentration drops to the second preset concentration, it means that the high-purity hydrogen in the gas storage chamber 11 has been discharged. At this time, the purity of the hydrogen in the gas storage chamber 11 is not high (it contains some nitrogen and oxygen, which does not meet the gas standard for the ejector). At this time, the partition plate 20 is readjusted to the maximum descending height, and the second liquid discharge port, the gas outlet 40 and the hydrogen discharge port 50 are closed, and the air inlet 30 is opened to continue to store and process the forklift exhaust gas.

[0167] Although the present invention is disclosed through the above embodiments, the protection scope of the present invention is not limited thereto. Without departing from the concept of the present invention, any deformation, replacement, etc. made to the above components shall fall within the scope of the claims of the present invention.

Claims

1. A fuel cell exhaust gas collection box for a forklift, characterized in that: include: A tank for storing liquid water and exhaust gas from the fuel cell system; A partition plate is disposed in the box body and can be lifted and lowered in the height direction of the box body, and the partition plate divides the box body into an air storage chamber and an exhaust chamber; An air inlet, connected to the air storage chamber, for introducing tail gas from the fuel cell system; An air outlet, connected to the exhaust chamber, for discharging oxygen and nitrogen; A hydrogen discharge port, connected to the top of the gas storage chamber, for discharging hydrogen; A first liquid outlet, connected to the side wall of the box body, and used to control the water level of the liquid water in the box body; The second liquid outlet is connected to the bottom of the box body and is used to drain the liquid water in the box body.

2. A fuel cell exhaust gas collection box for a forklift according to claim 1, characterized in that: The volume of the air storage chamber is greater than the volume of the exhaust chamber.

3. A fuel cell exhaust gas collection box for a forklift according to claim 1, characterized in that: Also includes: A silencer pipe connected to the end of the air inlet; The silencer pipe is provided with a plurality of openings for silencer.

4. A fuel cell exhaust gas collection box for a forklift according to claim 3, characterized in that: Also includes; a baffle plate, arranged between the partition plate and the muffler pipe; One end of the baffle is connected to the inner wall of the box body, and the other end extends vertically downward; The straight-line distance between the extended end of the baffle and the bottom of the box body is smaller than the straight-line distance between the bottom end of the muffler pipe and the bottom of the box body; The baffle is a mesh structure.

5. The fuel cell exhaust gas collection box for a forklift according to claim 1, characterized in that: Also includes: A liquid guide plate is arranged in the exhaust cavity, and two ends of the liquid guide plate are respectively connected to the top and the side wall of the box body; The liquid guide plate is a mesh structure; The horizontal projection area of ​​the liquid guide plate on the box body covers the air outlet.

6. A method for controlling drainage and exhaust, applied to the tail gas collection box according to any one of claims 1 to 5, characterized in that: The control steps include: Obtaining the volume ratio of the air storage chamber and the exhaust chamber; If the volume ratio of the gas storage chamber to the exhaust chamber is greater than 2:1, the first strategy is selected to control the drainage and exhaust of the exhaust gas collection box; If the volume ratio of the gas storage chamber to the exhaust chamber is less than 2:1, the second strategy is selected to control the drainage and exhaust of the exhaust gas collection box; Among them, the first strategy completes drainage and exhaust control based on the liquid level height in the exhaust collection box; The second strategy completes drainage and exhaust control based on the air pressure in the air storage chamber.

7. A drainage and exhaust control method according to claim 6, characterized in that: The first strategy includes the following control steps: Adjust the partition plate so that the bottom end of the partition plate is tangent to the bottom of the box; Open the air inlet and outlet, and close the hydrogen outlet and the second liquid outlet; Setting a first preset height, wherein the first preset height is consistent with the height of the lowest end of the first liquid outlet; When the liquid level in the air storage cavity rises from 0 to the first preset height, the bottom end of the partition plate always remains tangent to the liquid surface; When the liquid level in the gas storage cavity rises to a first preset height, the first liquid outlet is opened; When the hydrogen concentration in the gas storage chamber reaches a first preset concentration, the gas inlet is closed, the hydrogen outlet is opened, and the hydrogen is discharged; When the hydrogen concentration in the gas storage cavity reaches a second preset concentration, the hydrogen discharge port, the gas outlet and the first liquid outlet are closed, the second liquid outlet is opened, and the partition plate is adjusted to keep the bottom end of the partition plate at the first preset height position unchanged; When the liquid level drops to 0, close the second liquid outlet, adjust the partition plate so that the bottom end of the partition plate is tangent to the bottom of the box body, open the air inlet and outlet, and complete the drainage and exhaust control of the exhaust gas collection box.

8. A drainage and exhaust control method according to claim 6, characterized in that: The first strategy also includes the following control steps: Adjust the partition plate so that the bottom end of the partition plate is tangent to the bottom of the box; Open the air inlet and outlet, and close the hydrogen outlet and the second liquid outlet; Adjust the partition plate so that the bottom end of the partition plate is always tangent to the liquid surface; Setting a first preset height, wherein the first preset height is consistent with the height of the lowest end of the first liquid outlet; When the liquid level in the gas storage cavity rises to a first preset height, the first liquid outlet is opened; When the hydrogen concentration in the gas storage chamber reaches a first preset concentration, the gas inlet is closed, the hydrogen outlet is opened, and the hydrogen is discharged; When the hydrogen concentration in the gas storage cavity reaches a second preset concentration, the hydrogen discharge port is closed and the second liquid outlet is opened; When the liquid level drops to 0, the second liquid outlet is closed to complete the drainage and exhaust control of the tail gas collection box.

9. A method for controlling drainage and exhaust according to claim 7 or 8, characterized in that: The second strategy includes the following control steps: Adjust the partition plate so that the bottom end of the partition plate is tangent to the bottom of the box; Open the air inlet and outlet, and close the hydrogen outlet and the second liquid outlet; When the air pressure in the air storage chamber reaches a first preset air pressure value, the partition plate is adjusted so that the bottom end of the partition plate remains tangent to the liquid surface; When the air pressure in the air storage chamber reaches the first preset air pressure value again, the air inlet is closed, the hydrogen outlet is opened, and the hydrogen is discharged; When the hydrogen concentration in the gas storage chamber reaches a second preset concentration, the hydrogen discharge port is closed, the second liquid discharge port is opened, and the bottom end of the partition plate is kept at the second preset height position unchanged; When the liquid level drops to 0, the second drain port is closed, and the partition plate is adjusted so that the bottom end of the partition plate is tangent to the bottom of the box body, thereby completing the drainage and exhaust control of the exhaust gas collection box.

10. A drainage and exhaust control method according to claim 9, characterized in that: When the air pressure in the air storage chamber reaches the first preset air pressure value again, the hydrogen concentration in the air storage chamber is less than the first preset concentration.

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