An open cathode PEMFC stack temperature regulation system and regulation method

Abstract

The present application belongs to the field of fuel cell temperature control equipment, and specifically discloses an open cathode PEMFC stack temperature regulation system and regulation method, which includes a first airflow conveying mechanism and a second airflow conveying mechanism symmetrically arranged on both sides of the stack body, the first airflow conveying mechanism includes a plurality of first fans arranged in a vertical direction, the second airflow conveying mechanism includes a plurality of second fans arranged in a vertical direction, the airflow directions of the first fan and the second fan are both parallel to the cathode flow channel of the stack body, and the airflow directions of the first fan and the second fan are the same or opposite. Through the present application, the first fan and the second fan can generate airflows in the same or opposite directions, enhance the heat dissipation in the cathode flow channel to reduce the temperature, or make the airflow stagnation point located in the cathode flow channel to maintain the temperature and achieve temperature increase, thereby achieving temperature regulation of the stack body and maintaining its good performance.

Description

Technical Field

[0001] The present application relates to the field of fuel cell temperature control equipment, and more specifically, to an open cathode PEMFC stack temperature regulation system and regulation method. Background Art

[0002] Proton exchange membrane fuel cells (PEMFCs) are an important carrier for the application of hydrogen energy technology. They have the advantages of high efficiency, fast start-up, and zero emissions. They have broad application prospects in transportation, fixed power stations, and portable power sources.

[0003] An open cathode proton exchange membrane fuel cell (PEMFC) is a type of PEMFC. In existing open cathode air-cooled fuel cells, the cathode flow channel and cooling channel are either the same channel or separate. A fan is installed at the cathode flow channel inlet. The fan blows air through the cathode flow channel to provide reactant gases to the stack while also cooling the stack. The membrane electrode of an open cathode air-cooled fuel cell is directly exposed to air through the open cathode flow channel, which can affect its performance in both high and low temperature environments.

[0004] The temperature of an open cathode proton exchange membrane fuel cell (PEMFC) is crucial to its efficiency and service life. If the cell temperature is too low, the liquid water produced during the electrochemical reaction undergoes a phase transition at extremely low temperatures, condensing into ice and damaging the membrane electrode structure, causing irreversible damage to the cell. However, excessively high temperatures can lead to excessive internal cell temperatures, causing thermal management failure, localized overheating, and even membrane electrode sintering. Therefore, a system and method for regulating the temperature of an open cathode PEMFC stack is urgently needed. Summary of the Invention

[0005] In response to the defects of the existing technology, the present application provides an open cathode PEMFC stack temperature regulation system and regulation method, which aims to solve the problem that open cathode proton exchange membrane fuel cells are easily damaged when used in high or low temperature environments.

[0006] The present application provides an open cathode PEMFC stack temperature regulation system, which specifically includes a first airflow conveying mechanism and a second airflow conveying mechanism symmetrically arranged on both sides of the stack body, wherein the first airflow conveying mechanism includes a plurality of first fans arranged in a vertical direction, and the second airflow conveying mechanism includes a plurality of second fans arranged in a vertical direction, and the airflow directions of the first fan and the second fan are both parallel to the cathode flow channel of the stack body, and the airflow directions of the first fan and the second fan are the same or opposite.

[0007] The above technical solution conceived by the present application, compared with the prior art, since starting the first fan and the second fan can generate airflows in the same or opposite directions, the airflow enters the cathode flow channel. In a high-temperature environment, when the airflow directions are the same, the wind pressure and airflow velocity in the cathode flow channel are increased, heat dissipation is improved, and the temperature of the battery stack body is reduced; in a low-temperature environment, when the airflow directions are opposite, the stagnation points of the two airflows are located in the cathode flow channel, so that oxygen is supplied to the cathode of the battery stack body while keeping the heat of the battery stack from being lost, so as to maintain the temperature of the battery stack body or increase the temperature, thereby realizing temperature regulation of the battery stack body and maintaining its good performance when used in high or low-temperature environments.

[0008] As a further preference, the number of the first fans is the same as the number of the second fans, and each of the first fans and the second fans are located in a corresponding position.

[0009] By adopting the above technical solution, the airflows generated by the first fan and the second fan can correspond to each other, so that the corresponding two airflows can form a stagnation point inside the cathode flow channel, or can improve the effect of increasing the wind pressure and airflow velocity in the cathode flow channel, thereby improving the temperature regulation effect of the fuel cell stack body.

[0010] As a further preference, the plurality of first fans and second fans are uniformly and equidistantly arranged.

[0011] By adopting the above technical solution, the airflow generated by the first fan and the second fan is evenly distributed, and the airflow can evenly enter the cathode flow channel of the fuel cell stack, so that the temperature regulation effect of the fuel cell stack is better.

[0012] As a further preference, at least three of the first fans and the second fans are provided and are respectively located at the top, middle and bottom of the side of the stack body.

[0013] By adopting the above technical solution, the layout of the first fan and the second fan can generate the same or relative airflow at the top, middle and bottom sides of the stack body, further achieving uniform distribution of the airflow.

[0014] As a further preference, the temperature regulation system further includes a temperature sensing module and a control module, and the temperature sensing module and the first fans and second fans are all electrically connected to the control module.

[0015] By adopting the above technical solution, after the temperature sensing module monitors the temperature, the control module can automatically control the first fan and the second fan according to the monitored temperature data to change the airflow direction and wind speed, thereby realizing temperature regulation of the battery stack body and improving the automation of the system.

[0016] A method for regulating the temperature of an open cathode PEMFC stack is implemented using the above-mentioned temperature regulation system, comprising the following steps:

[0017] S1: starting a plurality of first fans and a second fan to allow air flow to enter the cathode flow channel;

[0018] S2: adjusting the airflow directions of the first fan and the second fan according to the use environment of the fuel cell stack;

[0019] If the use environment is a low temperature environment, adjusting the airflow directions of the first fan and the second fan to be opposite;

[0020] If the use environment is a normal temperature or high temperature environment, adjust the airflow directions of the first fan and the second fan to be the same;

[0021] S3: adjusting the wind speeds of the first fan and the second fan according to the temperature of the use environment to achieve temperature regulation of the fuel cell stack body.

[0022] As a further preference, in step S2, the temperature of the low-temperature environment is X, and X≤0°C.

[0023] By adopting the above technical solution, in a low temperature environment of 0°C or below, in order to ensure the normal use of the fuel cell stack, the airflow directions of the first fan and the second fan are adjusted to be relative, so that the airflow stagnation point is located inside the cathode flow channel, so that the stack body is heated up, thereby being able to maintain the temperature required for normal operation.

[0024] As further preferred, in step S2, the temperature of the high temperature environment is Y, and Y≥30°C, and the temperature of the normal temperature environment is Z, and 30°C>Z>0°C.

[0025] By adopting the above technical solution, in a high temperature environment of 30°C or above, in order to accelerate the heat dissipation of the battery stack body, the airflow directions of the first fan and the second fan are adjusted to be the same, so that the wind pressure in the cathode flow channel is superimposed, the airflow velocity is increased, and the heat in the cathode flow channel can be quickly dissipated, thereby achieving cooling of the battery stack body.

[0026] As further preferred, in step S3, when the temperature T of the operating environment is less than -10°C, the wind speeds of the first fans or the second fans are all equal, and there is a wind speed difference between the wind speeds of the first fans and the wind speeds of the second fans;

[0027] When the temperature of the operating environment is 0℃≥T≥-10℃, the wind speed of the first fan is equal to that of the corresponding second fan, and the wind speed of the first fan or the second fan located in the middle position is greater than the wind speed of the first fan or the second fan located at the top and bottom.

[0028] By adopting the above technical solution, in a low temperature environment of 0℃~-10℃, the operating temperature of the fuel cell stack body is high in the middle and low at both ends. The wind speed of the first fan or the second fan at the top and bottom is lower than the wind speed of the first fan or the second fan in the middle. Since the wind speed at the top and the bottom is relatively low, the cold air carried by the airflow blown in by the fan is not enough to resist the along-the-path loss in the cathode flow channel. At the same time, the heat inside the cathode flow channel will not cause heat loss with the flow of the airflow, and the airflow stagnation point position of the first fan and the second fan can be heated. Since the wind speed in the middle is relatively high, more cold air enters the cathode flow channel and forms an airflow stagnation point in the middle, which can cool the airflow stagnation point position, so that the overall temperature of the fuel cell stack body is relatively evenly distributed, avoiding local overheating and local hypothermia.

[0029] In a low temperature environment below -10°C, the airflow generated by the first fan and the airflow generated by the second fan form a stagnation point inside the cathode flow channel, and due to the wind speed difference between the wind speed of the first fan and the wind speed of the second fan, the positions of the airflow stagnation points are different. The airflow with a higher wind speed has a longer stroke, and the cold air blown in is used to resist the loss along the way, so that the airflow stagnation point position inside the fuel cell stack body is heated up. By adjusting the wind speed of the first fan and the wind speed of the second fan, different positions can be heated evenly, achieving a dynamic balance of heat, and thereby improving the normal operation efficiency of the fuel cell stack body.

[0030] As a further preferred embodiment, in step S3, when the temperature of the operating environment is 30°C>T>0°C, the wind speeds of the first fan and the second fan are uniform;

[0031] When the temperature T of the use environment is greater than or equal to 30° C., the wind speeds of the first fan and the second fan increase as the temperature rises.

[0032] By adopting the above technical solution, under normal temperature environment, the first fan and the second fan rotate at a uniform speed so that the airflow passes through the cathode flow channel to meet the heat dissipation of the battery stack body. When the temperature rises to 30°C or above, the wind speed of the first fan and the second fan increases and increases with the temperature, thereby increasing the airflow velocity to accelerate the heat dissipation of the battery stack body.

[0033] In general, the above technical solutions conceived by this application have the following technical advantages compared with the existing technology:

[0034] 1. Activating the first and second fans can generate airflows in the same or opposite directions, which flow into the cathode flow channel. In high-temperature environments, when the airflows are in the same direction, the wind pressure and airflow velocity in the cathode flow channel are increased, improving heat dissipation and lowering the temperature of the stack. In low-temperature environments, when the airflows are in opposite directions, the stagnation points of the two airflows are located in the cathode flow channel, supplying oxygen to the cathode of the stack while preventing heat loss from the stack, thereby maintaining or increasing the temperature of the stack. This allows the stack to be temperature-regulated, ensuring good performance in both high and low-temperature environments.

[0035] 2. In this application, when operating in a low-temperature environment of 0°C to -10°C, the temperature of the fuel cell stack is distributed with a high temperature in the middle and low temperatures at both ends. The wind speed of the first or second fan at the top and bottom is lower than that of the first or second fan at the middle. Due to the lower wind speed at the top and bottom, the cold air carried by the airflow from the fan is insufficient to offset the heat loss along the cathode flow channel. At the same time, the heat within the cathode flow channel is not lost with the airflow, thereby increasing the temperature at the airflow stagnation point of the first and second fans. Due to the higher wind speed in the middle, more cold air enters the cathode flow channel, forming an airflow stagnation point in the middle. This cools the airflow stagnation point, resulting in a more uniform temperature distribution of the overall fuel cell stack body and avoiding local overheating and hypothermia.

[0036] 3. In this application, in a low-temperature environment below -10°C, the airflow generated by the first fan and the airflow generated by the second fan form stagnation points within the cathode flow channel. Due to the speed difference between the first and second fans, the locations of the stagnation points are different. The higher-speed airflow has a longer travel distance, and the cool air blown in is used to counteract losses along the way, causing the stagnation points within the stack to heat up. By adjusting the speeds of the first and second fans, the temperatures at different locations can be evenly increased, achieving a dynamic heat balance and thereby improving the normal operating efficiency of the stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of the overall structure of the temperature control system provided in an embodiment of the present application;

[0038] Figure 2 This is a schematic diagram of the overall structure of the first fan and the second fan provided in an embodiment of the present application, in which the airflow directions are opposite and the wind speeds are the same;

[0039] Figure 3 This is a schematic diagram of the overall structure of the first fan and the second fan provided in an embodiment of the present application, in which the airflow directions of the first fan and the second fan are opposite and there is a wind speed difference;

[0040] Figure 4This is a schematic diagram of the overall structure of the first fan and the second fan provided in an embodiment of the present application, in which the airflow directions are the same;

[0041] Figure 5 This is a flow chart of the temperature adjustment method provided in an embodiment of the present application.

[0042] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0043] 1. Fuel cell stack body; 11. Cathode flow channel; 2. First airflow conveying mechanism; 21. First fan; 3. Second airflow conveying mechanism; 31. Second fan. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0045] Reference Figure 1 , an open cathode PEMFC stack temperature regulation system disclosed in the present application includes a first airflow conveying mechanism 2, a second airflow conveying mechanism 3, a temperature sensing module and a control module, wherein the first airflow conveying mechanism 2 and the second airflow conveying mechanism 3 are symmetrically arranged on both sides of the cylindrical stack body 1, specifically at the cathode flow channel inlet and outlet on the stack body 1, the first airflow conveying mechanism 2 includes a plurality of first fans 21 arranged in a vertical direction, the second airflow conveying mechanism 3 includes a plurality of second fans 31 arranged in a vertical direction, the airflow directions of the first fan 21 and the second fan 31 are parallel to the cathode flow channel 11 of the stack body 1, and the airflow directions of the first fan 21 and the second fan 31 are the same or opposite. When the stack body 1 is in a high-temperature environment, the airflow directions are the same, which increases the wind pressure and airflow velocity in the cathode flow channel 11, improves heat dissipation, and reduces the temperature of the stack body 1; when the stack body 1 is in a low-temperature environment, the airflow directions are opposite, and the stagnation points of the two airflows are located in the cathode flow channel 11, so as to supply oxygen to the cathode of the stack body 1 while keeping the heat of the stack from being lost, so as to maintain the temperature of the stack body 1 or increase the temperature, thereby achieving temperature regulation of the stack body 1.

[0046] Specifically, the number of first fans 21 and the number of second fans 31 are the same, and the positions of each first fan 21 and second fan 31 correspond to each other, that is, one first fan 21 corresponds to one second fan 31 in the horizontal direction, and the first fans 21 and second fans 31 are evenly distributed at equal distances.

[0047] More specifically, there are at least three first fans 21 and second fans 31, and in this embodiment, there are four of them. One first fan 21 is located at the top of one side of the stack body 1, two first fans 21 are located in the middle of one side of the stack body 1, one first fan 21 is located at the bottom of one side of the stack body 1, and four second fans 31 are arranged on the other side of the stack body 1 and correspond to the positions of the first fans 21.

[0048] Furthermore, the temperature sensing module and several first fans 21 and second fans 31 are electrically connected to the control module. After the temperature sensing module monitors the temperature, the control module can automatically control the first fan 21 and the second fan 31 according to the monitored temperature data to change the airflow direction and wind speed of the first fan 21 and the second fan 31, thereby realizing automatic temperature adjustment of the battery stack body 1. The temperature sensing module and the control module adopt temperature sensors and controllers commonly used in this field.

[0049] Reference Figure 5 The present application discloses a method for regulating the temperature of an open cathode PEMFC stack, comprising the following steps:

[0050] S1: Simultaneously start a plurality of first fans 21 and second fans 31 on both sides of the stack body 1 to allow air flow to enter the cathode flow channel 11;

[0051] S2: Adjust the airflow directions of the first fan 21 and the second fan 31 according to the use environment of the fuel cell stack body 1;

[0052] Reference Figure 2-3 If the operating environment is a low-temperature environment, adjust the airflow directions of the first fan 21 and the second fan 31 to be opposite; specifically, the temperature of the low-temperature environment is X, and X≤0°C;

[0053] Reference Figure 4 If the operating environment is a normal temperature environment or a high temperature environment, adjust the airflow directions of the first fan 21 and the second fan 31 to be the same; specifically, the temperature of the high temperature environment is Y, and Y≥30℃, the temperature of the normal temperature environment is Z, and 30℃>Z>0℃, the airflow directions of the first fan 21 and the second fan 31 are the same, so that the wind pressure in the cathode flow channel 11 is superimposed, the airflow velocity is increased, and the heat in the cathode flow channel 11 can be quickly dissipated, thereby achieving cooling of the fuel cell stack body 1.

[0054] S3: Adjust the wind speed of the first fan 21 and the second fan 31 according to the ambient temperature to achieve temperature regulation of the stack body 1; for details, refer to Figure 3When the temperature T of the operating environment is less than -10°C, the wind speeds of the first fans 21 or the second fans 31 are equal, and there is a wind speed difference between the wind speed of the first fan 21 and the wind speed of the second fan 31. The airflow generated by the first fan 21 and the airflow generated by the second fan 31 form a stagnation point inside the cathode flow channel 11. Since there is a wind speed difference between the wind speed of the first fan 21 and the wind speed of the second fan 31, the positions of the airflow stagnation points are different. The airflow with a higher wind speed has a longer stroke, and the cold air blown in is used to resist the loss along the way, so that the airflow stagnation point position inside the fuel cell stack body 1 is heated up. By adjusting the wind speed of the first fan 21 and the wind speed of the second fan 31, different positions can be heated up evenly, and the dynamic balance of heat in the fuel cell stack body 1 can be achieved.

[0055] Reference Figure 2 When the temperature of the operating environment is 0℃≥T≥-10℃, since the operating temperature of the fuel cell body 1 is high in the middle and low at both ends, the wind speed of the first fan 21 and the corresponding second fan 31 are equal, and the wind speed of the two first fans 21 or the second fans 31 located in the middle is greater than the wind speed of the first fan 21 or the second fan 31 located at the top and the bottom. Since the wind speed at the top and the bottom is relatively low, the cold air carried by the airflow blown in by the fan is not enough to resist the along-the-line loss in the cathode flow channel 11. At the same time, the heat inside the cathode flow channel 11 will not cause heat loss with the flow of the airflow, and the airflow stagnation point position of the first fan 21 and the second fan 31 can be heated; since the wind speed in the middle is relatively high, more cold air enters the cathode flow channel 11, and an airflow stagnation point is formed in the middle, which can cool the airflow stagnation point position, so that the overall temperature of the fuel cell body 1 is relatively evenly distributed, avoiding local overheating and local hypothermia.

[0056] When the temperature of the operating environment is a normal temperature environment of 30℃>T>0℃, the wind speed of the first fan 21 and the second fan 31 is uniform, and the airflow passing through the cathode flow channel can meet the heat dissipation of the battery stack body; when the temperature of the operating environment T≥30℃, the wind speed of the first fan 21 and the second fan 31 increases with the increase of temperature, increasing the airflow velocity to accelerate the heat dissipation of the battery stack body.

[0057] It should be understood that expressions such as "include" and "may include" used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "include" and / or "have" may be interpreted as indicating a specific characteristic, number, operation, constituent element, component, or combination thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0058] It should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0059] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0060] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0061] It is easy for those skilled in the art to understand that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A method for regulating the temperature of an open cathode PEMFC stack, characterized in that: An open cathode PEMFC stack temperature regulation system is used, the temperature regulation system comprising a first airflow conveying mechanism (2) and a second airflow conveying mechanism (3) symmetrically arranged on both sides of a stack body (1), the first airflow conveying mechanism (2) comprising a plurality of first fans (21) arranged in a vertical direction, the second airflow conveying mechanism (3) comprising a plurality of second fans (31) arranged in a vertical direction, the airflow directions of the first fans (21) and the second fans (31) being parallel to the cathode flow channel (11) of the stack body (1), and the airflow directions of the first fans (21) and the second fans (31) being the same or opposite; The stack temperature regulation method comprises the following steps: S1: starting a plurality of first fans (21) and second fans (31) to allow airflow to enter the cathode flow channel (11); S2: adjusting the airflow directions of the first fan (21) and the second fan (31) according to the use environment of the battery stack body (1); If the use environment is a low-temperature environment, the airflow directions of the first fan (21) and the second fan (31) are adjusted to be opposite; the temperature of the low-temperature environment is X, and X≤0°C; If the use environment is a normal temperature or high temperature environment, the airflow directions of the first fan (21) and the second fan (31) are adjusted to be the same; the temperature of the high temperature environment is Y, and Y ≥ 30°C, and the temperature of the normal temperature environment is Z, and 30°C>Z>0°C; S3: adjusting the wind speeds of the first fan (21) and the second fan (31) according to the temperature of the use environment to achieve temperature regulation of the battery stack body (1); when the temperature T of the use environment is less than -10°C, the wind speeds of the first fans (21) or the second fans (31) are equal, and there is a wind speed difference between the wind speed of the first fan (21) and the wind speed of the second fan (31); When the temperature of the use environment is 0°C ≥ T ≥ -10°C, the wind speed of the first fan (21) is equal to the wind speed of the corresponding second fan (31), and the wind speed of the first fan (21) or the second fan (31) located in the middle is greater than the wind speed of the first fan (21) or the second fan (31) located at the top and the bottom.

2. The open cathode PEMFC stack temperature regulation method according to claim 1, characterized in that: The number of the first fans (21) and the number of the second fans (31) are the same, and the positions of each of the first fans (21) and the second fans (31) correspond to each other.

3. The open cathode PEMFC stack temperature regulation method according to claim 2, characterized in that: The plurality of first fans (21) and second fans (31) are uniformly arranged at equal distances.

4. The open cathode PEMFC stack temperature regulation method according to claim 2, characterized in that: At least three of the first fans (21) and the second fans (31) are provided and are respectively located at the top, middle and bottom sides of the stack body (1).

5. The open cathode PEMFC stack temperature regulation method according to any one of claims 1 to 4, characterized in that: The temperature regulating system further comprises a temperature sensing module and a control module. The temperature sensing module and a plurality of the first fans (21) and the second fans (31) are all electrically connected to the control module.

6. The open cathode PEMFC stack temperature regulation method according to claim 1, characterized in that: In the step S3, when the temperature of the use environment is 30°C>T>0°C, the wind speeds of the first fan (21) and the second fan (31) are uniform; When the temperature T of the use environment is greater than or equal to 30° C., the wind speeds of the first fan (21) and the second fan (31) increase as the temperature rises.

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