Cooling flow channel structure, bipolar plate and single battery

Abstract

The invention provides a cooling flow channel structure, a bipolar plate and a single cell, and relates to the technical field of fuel cells. The cooling flow channel structure is attached to two polar plates and comprises a first cooling flow channel groove and a second cooling flow channel groove, the first cooling flow channel grooves and the second cooling flow channel grooves are correspondingly communicated to form a plurality of cooling cavities; at least one of the multiple cooling cavities comprises a smooth flow section and a flow limiting section, the flow limiting section is located between the two smooth flow sections, and the cross sectional area of the cooling cavity at the position of the flow limiting section is smaller than that of the cooling cavity at the position of the smooth flow section. According to the bipolar plate provided by the invention, the technical problem that a cooling flow channel is easy to block in the prior art is solved, and the output voltage stability of a galvanic pile is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a cooling channel structure, a bipolar plate and a single cell. Background Art

[0002] A proton exchange membrane hydrogen fuel cell is a type of fuel cell that, in principle, functions as a reverse device for water electrolysis. Each cell consists of two bipolar plates, one cathode and one anode, with a membrane electrode positioned between them. When operating, the proton exchange membrane hydrogen fuel cell functions as a direct current (DC) power source, with the anode serving as the negative electrode and the cathode serving as the positive electrode.

[0003] A proton exchange membrane hydrogen fuel cell (PEMFC) is a device that directly utilizes hydrogen to generate electricity, converting the chemical energy generated by the reaction of hydrogen and oxygen into usable electricity. To achieve this, the flow fields on either side of the bipolar plates are fed with hydrogen and air. Because the reaction is exothermic, coolant is passed through the bipolar plates to dissipate the heat generated and maintain the overall temperature stability of the stack.

[0004] In the prior art, there is a cooling cavity between the bipolar plates. The cooling cavity is composed of the cooling liquid flow channel groove of the anode plate and the cooling liquid flow channel groove of the cathode plate. The coolant can flow directly from the inlet of the cooling cavity to the outlet of the cooling cavity.

[0005] However, using the design of the existing technology, the inventors found that the output voltage of the battery stack was unstable. Summary of the Invention

[0006] The purpose of the present invention is to provide a cooling channel structure, a bipolar plate and a single battery to alleviate the technical problem of easy clogging of the cooling channel in the prior art, thereby improving the output voltage stability of the battery stack.

[0007] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0008] In a first aspect, the cooling channel structure provided by the present invention is attached to two electrode plates and includes a first cooling channel groove and a second cooling channel groove;

[0009] The first cooling channel groove and the second cooling channel groove are correspondingly connected to form a cooling chamber, and a plurality of cooling chambers are provided;

[0010] Among the multiple cooling chambers, at least one cooling chamber includes a free flow section and a flow limiting section, the flow limiting section is located between the two free flow sections, and the cross-sectional area of the cooling chamber at the flow limiting section is smaller than the cross-sectional area of the cooling chamber at the free flow section.

[0011] Further, a plurality of current-limiting sections are provided, and the plurality of current-limiting sections are arranged at intervals along the extending direction of the cooling chamber.

[0012] Further, the first cooling channel groove or the second cooling channel groove is provided with a current-limiting portion;

[0013] The current-limiting portion of the first cooling channel groove communicates with the second cooling channel groove to form the current-limiting section, or the current-limiting portion of the second cooling channel groove communicates with the first cooling channel groove to form the current-limiting section.

[0014] Further, the first cooling channel groove or the second cooling channel groove provided with the current-limiting portion includes a smooth-flow portion, the current-limiting portion is located between the two smooth-flow portions, and the cross-sectional area of the cooling chamber at the smooth-flow portion is larger than the cross-sectional area of the cooling chamber at the current-limiting portion.

[0015] Further, the upper surface of the current-limiting portion is flush with the joint surface of the two electrode plates.

[0016] Further, one of the adjacent two cooling chambers is provided with the current-limiting section.

[0017] Further, the cooling channel structure is arranged in the reaction area of the electrode plate.

[0018] In a second aspect, the bipolar plate provided by the present invention includes an anode plate, a cathode plate, and the cooling channel structure as described in any one of the above;

[0019] The first surface of the anode plate is arranged opposite to the first surface of the cathode plate;

[0020] A plurality of first cooling channel grooves in the cooling channel structure are provided on the first surface of the anode plate, the plurality of first cooling channel grooves are arranged at intervals along the width direction of the anode plate, and a plurality of second cooling channel grooves in the cooling channel structure are provided on the first surface of the cathode plate.

[0021] Further, the cooling channel structure is arranged in the reaction area of the bipolar plate.

[0022] In a third aspect, the single cell provided by the present invention includes a membrane electrode and the bipolar plate as described in any one of the above;

[0023] The membrane electrode is arranged between the two bipolar plates.

[0024] Based on the above technical solutions, the technical effects that the present invention can achieve are analyzed as follows:

[0025] The cooling channel structure provided by the present invention is attached to two plates, and includes a first cooling channel groove and a second cooling channel groove; the first cooling channel groove and the second cooling channel groove are correspondingly connected to form a cooling chamber, and there are multiple cooling chambers; among the multiple cooling chambers, at least one cooling chamber includes a smooth flow section and a flow limiting section, the flow limiting section is located between two smooth flow sections, and the cross-sectional area of the cooling chamber at the flow limiting section is smaller than that at the smooth flow section. The first cooling channel groove and the second cooling channel groove are opposite and connected to form a cooling chamber for the coolant to flow through, so as to achieve the effect of cooling the plate provided with the cooling channel structure. At least one of the multiple cooling chambers includes a smooth flow section and a flow limiting section. When the coolant flows from the smooth flow section to the flow limiting section, since the cross-sectional area of the cooling chamber at the flow limiting section becomes smaller, according to Bernoulli's principle, the fluid static pressure at the flow limiting section increases, increasing the flow velocity of the fluid; because the cooling chamber is provided with a flow limiting section, on the basis of only frictional losses originally existing, a pressure difference caused by the pressure loss due to the sudden change in flow velocity is added, so the pressure drop increases, preventing the cooling chamber from being blocked, and greatly ensuring the uniformity of the coolant distribution among multiple groups of plates. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required to be used in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 is a partial schematic view of the cooling flow field of a bipolar plate in the prior art;

[0028] Figure 2 is Figure 1 the sectional view at A-A in

[0029] Figure 3 is the cross-section of the cooling channel structure provided by the embodiment of the present invention Figure 1 ;

[0030] Figure 4 is the cross-section of the cooling channel structure provided by the embodiment of the present invention Figure 2 ;

[0031] Figure 5 is the cross-section of the cooling channel structure provided by the embodiment of the present invention Figure 3 ;

[0032] Figure 6 is the cross-section of the cooling channel structure provided by the embodiment of the present invention Figure 1 (smooth flow section);

[0033] Figure 7 Cross-section of the cooling channel structure provided by the embodiment of the present invention Figure 2 (Flow-limiting section);

[0034] Figure 8 Partial structural schematic diagram of the bipolar plate provided by the embodiment of the present invention;

[0035] Figure 9 is Figure 8 Cross-sectional view at B-B in;

[0036] Figure 10 Structural schematic diagram of the bipolar plate provided by the embodiment of the present invention.

[0037] Icon:

[0038] 100 - Anode plate; 110 - First cooling channel groove; 111 - Unobstructed flow part; 112 - Flow-limiting part; 120 - Anode flow field; 200 - Cathode plate; 210 - Second cooling channel groove; 220 - Cathode flow field; 300 - Cooling chamber; 310 - Unobstructed flow section; 320 - Flow-limiting section; Detailed implementation manners

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0041] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0042] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, terms such as "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0043] In addition, terms such as "horizontal", "vertical", "hanging" do not mean that the components are required to be absolutely horizontal or hanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0044] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0045] As described in the background art, when using the stack design in the prior art, there is a problem of unstable output voltage of the stack. The inventor has found through research that one of the reasons for this problem is that in the current design, the pressure drop in the cooling cavity of the single cell's coolant flow channel is insufficient, resulting in blockage of the coolant in the cooling cavity, and then uneven distribution of the coolant between the cells at the stack level, causing a deviation in the battery voltage.

[0046] Based on this, the present invention provides a coolant flow channel structure. By arranging a flow-limiting section 320 and a smooth-flow section 310 in the cooling chamber 300, due to the function of the flow-limiting section 320, on the basis of only frictional losses originally existing, a pressure difference caused by the pressure loss due to the sudden change in flow velocity is increased, thus resulting in an increase in pressure drop, preventing the cooling chamber 300 from being blocked, and greatly ensuring the uniformity of coolant distribution between multiple groups of plates, solving the problem that the cooling chamber 300 is easily blocked, and further improving the stability of voltage output.

[0047] The following will describe in detail some embodiments of the present invention with reference to the drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0048] Embodiment 1

[0049] Please refer to Figure 1 and Figure 2 , Figure 1 and Figure 2 are structural diagrams of the cooling flow field of bipolar plates in the prior art. It can be seen that the cooling flow field is unobstructed, and there is a problem of insufficient pressure drop in the cooling flow field, resulting in blockage of the coolant in the cooling flow field; moreover, it causes uneven distribution of the coolant between the batteries at the stack level, and further causes deviation in the battery voltage.

[0050] In view of this, please refer to Figures 3 to 7 . The cooling channel structure provided by the embodiment of the present invention is attached to two plates, and includes a first cooling channel groove 110 and a second cooling channel groove 210; the first cooling channel groove 110 and the second cooling channel groove 210 are correspondingly connected to form a plurality of cooling chambers 300, and there are a plurality of cooling chambers 300; among the plurality of cooling chambers 300, at least one cooling chamber 300 includes a smooth flow section 310 and a flow limiting section 320, the flow limiting section 320 is located between two smooth flow sections 310, and the cross-sectional area of the cooling chamber 300 at the flow limiting section 320 is smaller than the cross-sectional area of the cooling chamber 300 at the smooth flow section 310.

[0051] Specifically, the coolant enters the inlet distribution area from the coolant inlet manifold, and is distributed by the inlet distribution area to each coolant flow channel in the reaction area of the plate, that is, it flows into the cooling chambers 300 of each flow channel. The coolant in each cooling chamber 300 then flows into the coolant outlet manifold through the outlet distribution area. In one embodiment, the cooling channel structure is provided in the reaction area of the plate. Please refer to Figure 6 and Figure 7 , Figure 6 is a cross-sectional view of the cooling chamber 300 at the smooth flow section 310, Figure 7 is a cross-sectional view of the cooling chamber 300 at the flow limiting section 320. The cross-sectional area of the cooling chamber 300 at the smooth flow section 310 is larger than the cross-sectional area of the cooling chamber 300 at the flow limiting section 320; it should be noted that Figure 6 and Figure 7 only intercept one cooling chamber 300 for demonstration. There are multiple cooling chambers 300 in a normal plate. Please refer to Figures 3 to 4 . Taking the anode plate 100 above and the cathode plate 200 below as an example, the anode plate 100 is provided with a first cooling channel groove 110, and the cathode plate 200 is provided with a second cooling channel groove 210. The first cooling channel groove 110 and the second cooling channel groove 210 are opposite to form a cooling chamber 300. The place where the cross-sectional area of the cooling chamber 300 is small is the flow limiting section 320, and the place where the cross-sectional area is large is the smooth flow section 310; for example: as Figure 3Among them, the first cooling channel groove 110 includes a smooth flow portion 111 and a downwardly protruding flow limiting portion 112. The cross-sectional area of the cooling chamber 300 formed by the second cooling channel groove 210 and the smooth flow portion 111 is large, which is the smooth flow section 310; the cross-sectional area of the cooling chamber 300 formed by the second cooling channel groove 210 and the flow limiting portion 112 is small, which is the flow limiting section 320.

[0052] The first cooling channel groove 110 and the second cooling channel groove 210 are opposite and connected to form a cooling chamber 300 for the coolant to flow through, so as to achieve the effect of cooling the electrode plate provided with the cooling channel structure. At least one of the plurality of cooling chambers 300 includes a smooth flow section 310 and a flow limiting section 320. When the coolant flows from the smooth flow section 310 to the flow limiting section 320, since the cross-sectional area of the cooling chamber 300 at the flow limiting section 320 becomes smaller, according to Bernoulli's principle, the hydrostatic pressure at the flow limiting section 320 increases, increasing the flow velocity of the fluid; because the cooling chamber 300 is provided with a flow limiting section 320, on the basis of only frictional losses originally existing, a pressure difference caused by the pressure loss due to the sudden change in flow velocity is added, so the pressure drop increases, preventing the cooling chamber 300 from being blocked, and greatly ensuring the uniformity of the coolant distribution among multiple groups of electrode plates.

[0053] The structure and shape of the cooling channel structure are described in detail below:

[0054] In an alternative embodiment of the present invention, referring to Figure 5 , Figure 5 in which the arrow is the flow direction of the coolant, and a plurality of flow limiting sections 320 are provided, and the plurality of flow limiting sections 320 are arranged at intervals along the extending direction of the cooling chamber 300.

[0055] Specifically, the distance between two adjacent flow limiting sections 320 is greater than 5 mm.

[0056] The provision of a plurality of flow limiting sections 320 enables the coolant flowing through the cooling chamber 300 to undergo multiple sudden changes in flow velocity, avoiding blockage of the cooling chamber 300.

[0057] In an alternative embodiment of the present invention, the first cooling channel groove 110 or the second cooling channel groove 210 is provided with a flow limiting portion 112; the flow limiting portion 112 of the first cooling channel groove 110 is opposite to the second cooling channel groove 210 and forms a flow limiting section 320, or the flow limiting portion 112 of the second cooling channel groove 210 is opposite to the first cooling channel groove 110 and forms a flow limiting section 320.

[0058] Specifically, the axis of the cooling chamber 300 can be set as a straight line extending along the length direction of the electrode plate, or as a winding curve, and the embodiments of the present invention are not limited thereto.

[0059] The flow limiting part 112 is arranged in the first cooling channel groove 110 or the second cooling channel groove 210, so that the cooling cavity includes a flow limiting section 320, and further realizes an increase in the pressure difference caused by the pressure loss due to the sudden change in flow velocity on the basis of only frictional loss existing originally. Therefore, the pressure drop increases, preventing the cooling chamber 300 from being blocked, and greatly ensuring the uniformity of the coolant distribution between multiple groups of electrode plates.

[0060] As an implementation manner, the flow limiting part 112 can be set as a filling block, which is filled in the first cooling channel groove 110 or the second cooling channel groove 210 to reduce the cross-sectional area of the first cooling channel groove 110 or the second cooling channel groove 210.

[0061] Specifically, when there are multiple flow limiting sections 320, there are multiple flow limiting parts 112, and the multiple flow limiting parts 112 are all arranged in the first cooling channel groove 110; or, the multiple flow limiting parts 112 are all arranged in the second cooling channel groove 210; or, refer to Figure 5 , the multiple flow limiting parts 112 are divided into two parts, one part is arranged in the first cooling channel groove 110, and the other part is arranged in the second cooling channel groove 210. More preferably, the filling block is fixedly connected to the first cooling channel groove 110 or the second cooling channel groove 210, such as by bonding.

[0062] The filling block fills the first cooling channel groove 110 or the second cooling channel groove 210, truncating the first cooling channel groove 110 or the second cooling channel groove 210; taking the filling block filling the first cooling channel groove 110 as an example, please refer to Figure 3, when the coolant in the first cooling channel groove 110 flows to the filling block, the flow velocity suddenly drops to 0. According to Bernoulli's principle, the static pressure of the coolant at this point increases, which will cause the coolant to flow reversely towards the second cooling channel groove 210, cross over to the second cooling channel groove 210, and finally flow towards the outlet of the coolant manifold; because the filling block is filled in the first cooling channel groove 110, the coolant originally in the first cooling channel groove 110 reversely flows to the second cooling channel groove 210, increasing the pressure difference caused by the pressure loss due to the sudden change in flow velocity on the basis of the original frictional loss only. Therefore, the pressure drop increases, preventing the cooling chamber 300 from being blocked and greatly ensuring the uniformity of coolant distribution among multiple groups of electrode plates. Among them, after blocking and limiting the flow, when the coolant in the first cooling channel groove 110 of the anode flows through the flow-limiting section 320, it will be forced to be squeezed into the second cooling channel groove 210 of the cathode plate 200 for "crossing over", that is, the coolant in the first cooling groove flows along the extension direction of the first cooling groove to the flow-limiting section 320, then flows in a direction perpendicular to the extension direction of the first cooling groove into the second cooling groove, and then flows along the extension direction of the second cooling groove. The flow direction of the coolant changes in a bent manner; and after flowing through the flow-limiting section 320, the flow direction of the coolant in the second cooling groove changes in a bent manner again and flows into the first cooling groove; vice versa, the same is true as Figure 4 。

[0063] As another implementation manner, the first cooling channel groove 110 or the second cooling channel groove 210 provided with the flow-limiting portion 112 includes a smooth flow portion 111. The flow-limiting portion 112 is located between two smooth flow portions 111, and the cross-sectional area of the cooling chamber 300 at the smooth flow portion 111 is larger than the cross-sectional area of the cooling chamber 300 at the flow-limiting portion 112.

[0064] Specifically, referring to Figure 3 , when the first cooling channel groove 110 includes the flow-limiting portion 112, the smooth flow portion 111 and the flow-limiting portion 112 are machined on the first surface of the anode plate 100, and the depression depth of the smooth flow portion 111 is greater than the depression depth of the flow-limiting portion 112, so as to realize the anode plate 100 with the first cooling channel groove 110 having the smooth flow portion 111 and the flow-limiting portion 112, reducing the production difficulty. Similarly, referring to Figure 4 , when the second cooling channel groove 210 includes the flow-limiting portion 112, the smooth flow portion 111 and the flow-limiting portion 112 that are communicated with each other are machined on the first surface of the cathode plate 200, and the depression depth of the smooth flow portion 111 is greater than the depression depth of the flow-limiting portion 112, so as to realize the cathode plate 200 with the second cooling channel groove 210 having the smooth flow portion 111 and the flow-limiting portion 112, reducing the production difficulty.

[0065] The flow-limiting portion 112 truncates the first cooling channel groove 110 or the second cooling channel groove 210; taking the first cooling channel groove 110 provided with the flow-limiting portion 112 as an example, please refer toFigure 3 When the coolant in the first cooling channel groove 110 flows to the flow limiting part 112, the flow velocity suddenly drops to 0. According to Bernoulli's principle, the static pressure of the coolant at this place increases at this time, which will cause the coolant to flow reversely towards the second cooling channel groove 210, cross over to the inside of the second cooling channel groove 210, and finally flow to the outlet of the coolant manifold; because the first cooling channel groove 110 is cut off by the flow limiting part 112, the coolant originally in the first cooling channel groove 110 reversely flows to the second cooling channel groove 210, increasing the pressure difference caused by the pressure loss due to the sudden change in flow velocity on the basis of the original only frictional loss, so the pressure drop increases, preventing the cooling chamber 300 from being blocked, and greatly ensuring the uniformity of the coolant distribution between the bipolar plates. Among them, after the flow is blocked and limited, when the coolant in the first cooling channel groove 110 of the anode flows through the flow limiting section 320, it will be forced to be squeezed into the second cooling channel groove 210 of the cathode plate 200 for "crossing over", that is, the coolant in the first cooling groove flows along the extension direction of the first cooling groove to the flow limiting section 320, and then flows in a direction perpendicular to the extension direction of the first cooling groove into the second cooling groove, and then flows along the extension direction of the second cooling groove, and the flow direction of the coolant changes in a bent shape; and after flowing through the flow limiting section 320, the flow direction of the coolant in the second cooling groove changes in a bent shape again and flows into the first cooling groove; vice versa, see Figure 4 .

[0066] In an alternative embodiment of the present invention, the upper surface of the flow limiting part 112 is flush with the joint surface of the two electrode plates.

[0067] Specifically, the cross-sectional shape and size of the first cooling channel groove 110 at the smooth flow section 310 of the cooling cavity are the same as those of the second cooling channel groove 210; the cross-sectional size of the first cooling channel groove 110 or the second cooling channel groove 210 at the flow limiting section 320 of the cooling cavity is 0, and correspondingly, the cross-sectional shape and size of the second cooling channel groove 210 or the first cooling channel groove 110 remain unchanged. Therefore, the cross-sectional area of the cooling chamber 300 at the flow limiting section 320 is half of the cross-sectional area of the cooling chamber 300 at the smooth flow section 310. That is, at the flow limiting section 320 of the cooling cavity, when the cross-sectional size of the first cooling channel groove 110 is 0, the cross-sectional shape and size of the second cooling channel groove 210 are the same as those of the second cooling channel groove 210 at the smooth flow section 310 of the cooling cavity to keep the cooling cavity unobstructed; when the cross-sectional size of the second cooling channel groove 210 is 0, the cross-sectional shape and size of the first cooling channel groove 110 are the same as those of the first cooling channel groove 110 at the smooth flow section 310 of the cooling cavity to keep the cooling cavity unobstructed.

[0068] The upper surface of the current-limiting part 112 is flush with the joint surfaces of the two plates, which facilitates the processing of the current-limiting part 112 and can completely cut off the coolant. When the coolant flows through the cut-off area, the flow rate drops suddenly to 0. According to Bernoulli's principle, the hydrostatic pressure of the fluid at this point increases, which will cause the coolant to flip and flow into the cooling grooves of the other plate, climb over to the cooling grooves of the other plate, and finally flow to the coolant manifold outlet. Under this design, the coolant of the anode and cathode plates 100 changes its flow direction at the cut-off point. At the same time, on the basis of only frictional losses originally, a pressure difference caused by the pressure loss due to the sudden change in flow rate is added, so the pressure drop increases, preventing the cooling chamber 300 from being blocked, and greatly ensuring the uniformity of the coolant distribution between the bipolar plates. Among them, after the current is blocked by the current-limiting part, when the coolant in the first cooling flow channel groove 110 of the anode flows through the current-limiting section 320, it will be forced to be squeezed into the second cooling flow channel groove 210 of the cathode plate 200 for "climbing over", that is, the coolant in the first cooling groove flows along the extension direction of the first cooling groove to the current-limiting section 320, and then flows into the second cooling groove in a direction perpendicular to the extension direction of the first cooling groove, and then flows along the extension direction of the second cooling groove. The flow direction of the coolant changes in a bending manner; and after flowing through the current-limiting section 320, the flow direction of the coolant in the second cooling groove changes in a bending manner again and flows into the first cooling groove; vice versa.

[0069] In an alternative embodiment of the present invention, at least one cooling chamber 300 is provided with a current-limiting section 320.

[0070] Specifically, in one of the two adjacent cooling chambers 300, a current-limiting section 320 is provided; or, the cooling chambers 300 provided with current-limiting sections 320 and the cooling chambers 300 not provided with current-limiting sections 320 are arranged alternately; or, each cooling chamber 300 is provided with a current-limiting section 320. Further, in this embodiment, current-limiting sections 320 are provided at both ends of the cooling chamber 300 provided with a current-limiting section 320 near the coolant manifold inlet and outlet.

[0071] The cooling chamber 300 is provided with a current-limiting section 320 to prevent the cooling chamber 300 from being blocked.

[0072] In this embodiment, the plates are made of graphite material, and the processing of the current-limiting section 320 is completed during the plate forming process. Processing techniques such as stamping, molding, and etching can be used; of course, the cooling flow channel structure of the present invention can also be applied to metal plates, composite material plates, or plates made of other materials. The processing methods of different materials will be different. For example, metal plates can be formed with current-limiting sections 320 by machining methods such as etching, and the rest of the materials will not be elaborated too much.

[0073] Embodiment Two

[0074] The bipolar plate provided by the embodiment of the present invention includes an anode plate 100 and a cathode plate 200; the first surface of the anode plate 100 is disposed opposite to the first surface of the cathode plate 200; a plurality of first cooling flow channel grooves 110 are provided on the first surface of the anode plate 100, and the plurality of first cooling flow channel grooves 110 are spaced along the width direction of the anode plate 100. A plurality of second cooling flow channel grooves 210 are provided on the first surface of the cathode plate 200, and the plurality of second cooling flow channel grooves 210 communicate with the plurality of first cooling flow channel grooves 110 one by one to form a plurality of cooling chambers 300; among the plurality of cooling chambers 300, at least one cooling chamber 300 includes a smooth flow section 310 and a flow limiting section 320. The two ends of the flow limiting section 320 are respectively communicated with the two smooth flow sections 310, and the cross-sectional area of the cooling chamber 300 at the flow limiting section 320 is smaller than the cross-sectional area of the cooling chamber 300 at the smooth flow section 310.

[0075] Specifically, please refer to Figure 10 , the coolant enters from the coolant inlet manifold into the inlet distribution area, and is distributed by the inlet distribution area to each coolant flow channel in the reaction area of the bipolar plate, that is, it flows into the cooling chambers 300 of each flow channel. The coolant in each cooling chamber 300 then flows into the coolant outlet manifold through the outlet distribution area. In one embodiment, the cooling flow channel structure is provided in the reaction area of the bipolar plate. Both the cathode plate 200 and the anode plate 100 are set as rectangles and have the same length direction. Further, the first surface of the cathode plate 200 is recessed downward to form the first cooling flow channel groove 110; similarly, the first surface of the anode plate 100 is recessed downward to form the second cooling flow channel groove 210. More preferably, the cathode plate 200 and the anode plate 100 are connected by bonding or welding.

[0076] The first cooling flow channel groove 110 and the second cooling flow channel groove 210 are opposite and communicate with each other to form a cooling chamber 300 for the coolant to flow through, so as to reduce the temperature of the bipolar plate and achieve the cooling effect. At least one of the plurality of cooling chambers 300 includes a flow limiting section 320 with a cross-sectional area smaller than that of the smooth flow section 310. When the coolant flows from the smooth flow section 310 to the flow limiting section 320, because the cross-sectional area of the flow limiting section 320 becomes smaller, according to Bernoulli's principle, the hydrostatic pressure of the fluid at the flow limiting section 320 increases, increasing the flow velocity of the fluid; because the cooling chamber 300 is provided with a flow limiting section 320, on the basis of only the original frictional loss, a pressure difference caused by the pressure loss due to the sudden change in flow velocity is added, so the pressure drop increases, preventing the cooling chamber 300 from being blocked, and greatly ensuring the uniformity of the coolant distribution between the bipolar plates.

[0077] In an alternative solution of the embodiment of the present invention, an anode flow field 120 is provided on the second surface of the anode plate 100, and a cathode flow field 220 is provided on the second surface of the cathode plate 200.

[0078] The anode plate 100 is provided with an anode flow field 120, and the cathode plate 200 is provided with a cathode flow field 220, enabling the bipolar plate to react with the proton exchange membrane, thereby achieving the power generation effect of a single cell.

[0079] The following is a calculation and comparison of the bipolar plate provided in this embodiment and the bipolar plate in the prior art:

[0080] Please refer to Figure 1 and Figure 2 , Figure 1 and Figure 2 are the structural diagrams of the cooling flow field of the bipolar plate in the prior art. Figure 1 The arrows in indicate the flow direction of the coolant; it can be seen that the cooling flow field is unobstructed. During the process of the coolant flowing from the inlet to the outlet of the cooling flow field, it only bears frictional losses, where the frictional losses are related to the flow rate of the coolant, the density of the coolant, and the cross-sectional diameter of the pipe through which the coolant flows. Here, we can assume that the pressure loss borne by the coolant is 10 kPa, that is, the pushing pressure difference for pushing the coolant contained in its field from the inlet to the outlet is 10 kPa. At the same time, assuming that the sum of the total pressure drops (the pressure difference represents the pressure difference between the start and end of a section of the flow channel; the pressure drop is the pressure loss generated by the fluid flow; the pressure drop is the same as the pressure difference) at the inlet and outlet of the coolant manifold is 2 kPa, then the uniformity of its manifold can be initially estimated to be within 2 kPa / 10 kPa = ±20%, that is, the coolant flow rate deviation between cells will not exceed 20%.

[0081] Please refer to Figure 8 and Figure 9 , Figure 8 and Figure 9 are the structural schematic diagrams of the cooling chamber 300 of the bipolar plate provided in the embodiment of the present invention. Figure 8 and Figure 9 The arrows in indicate the flow direction of the coolant; it can be seen that in this embodiment, part of the cooling chamber 300 of the anode plate 100 or the cathode plate 200 is truncated. When the coolant flows through the truncated area, the flow rate drops to 0 suddenly. According to Bernoulli's principle, the hydrostatic pressure at this place increases at this time, which will cause the coolant to flow reversely into the cooling groove of the other plate, cross over to the cooling groove of the other plate, and finally flow to the coolant manifold outlet. Under this design, the coolant of the anode and cathode plates 100 changes its flow direction at the truncation point. At the same time, on the basis of only frictional losses originally existing, a pressure difference caused by the pressure loss due to the sudden change in flow rate is added, thus resulting in an increase in the pressure drop. Assuming that the increased pressure drop is 15 kPa, then the pushing pressure of the coolant from the inlet to the outlet becomes 15 kPa. At the same time, the uniformity between the bipolar plates on the entire stack level is optimized to 2 kPa / 15 kPa = ±13%, greatly ensuring the uniformity of the coolant distribution between the bipolar plates.

[0082] Embodiment III

[0083] The single cell provided by the embodiment of the present invention includes the bipolar plate in Embodiment II, so it also has all the beneficial effects in Embodiment II, which will not be elaborated here.

[0084] In an alternative embodiment of the present invention, the single cell includes a proton exchange membrane, and two bipolar plates are respectively arranged on both sides of the proton exchange membrane.

[0085] Specifically, the single cell is applied to a fuel cell, and a plurality of single cells are provided and connected in series.

[0086] The proton exchange membrane reacts with the bipolar plates on both sides of the proton exchange membrane to convert chemical energy into electrical energy.

[0087] 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 them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cooling channel structure, the cooling channel structure is attached to two electrode plates, characterized in that, Comprising: A first cooling channel groove (110) and a second cooling channel groove (210); The first cooling channel groove (110) and the second cooling channel groove (210) communicate correspondingly to form a cooling chamber (300), and a plurality of the cooling chambers (300) are provided; Among the plurality of cooling chambers (300), at least one of the cooling chambers (300) includes a smooth flow section (310) and a flow limiting section (320), the flow limiting section (320) is located between two of the smooth flow sections (310), and the cross-sectional area of the cooling chamber (300) at the flow limiting section (320) is smaller than the cross-sectional area of the cooling chamber (300) at the smooth flow section (310).

2. The cooling flow path structure according to claim 1, characterized in that, A plurality of the flow limiting sections (320) are provided, and the plurality of flow limiting sections (320) are arranged at intervals along the extending direction of the cooling chamber (300).

3. The cooling channel structure according to claim 1, wherein The first cooling channel groove (110) or the second cooling channel groove (210) is provided with a flow limiting portion (112); The flow limiting portion (112) of the first cooling channel groove (110) faces the second cooling channel groove (210) and forms the flow limiting section (320), or the flow limiting portion (112) of the second cooling channel groove (210) faces the first cooling channel groove (110) and forms the flow limiting section (320).

4. The cooling channel structure according to claim 3, wherein, The first cooling channel groove (110) or the second cooling channel groove (210) provided with the flow limiting portion (112) includes a smooth flow portion (111), the flow limiting portion (112) is located between two of the smooth flow portions (111), and the cross-sectional area of the cooling chamber (300) at the smooth flow portion (111) is larger than the cross-sectional area of the cooling chamber (300) at the flow limiting portion (112).

5. The cooling channel structure according to claim 3 or 4, wherein The upper surface of the flow limiting portion (112) is flush with the joint surface of the two plates.

6. The cooling flow channel structure according to claim 1, characterized in that, Among two adjacent cooling chambers (300), one of the cooling chambers (300) is provided with the flow limiting section (320).

7. The cooling flow channel structure according to claim 1, wherein The cooling channel structure is arranged in the reaction area of the plate.

8. A bipolar plate, characterized in that, Comprising an anode plate (100), a cathode plate (200) and the cooling channel structure according to any one of claims 1-7; The first surface of the anode plate (100) is arranged opposite to the first surface of the cathode plate (200); The first surface of the anode plate (100) is provided with a plurality of first cooling channel grooves (110) in the cooling channel structure, the plurality of first cooling channel grooves (110) are arranged at intervals along the width direction of the anode plate (100), and the first surface of the cathode plate (200) is provided with a plurality of second cooling channel grooves (210) in the cooling channel structure.

9. The bipolar plate according to claim 8, wherein The cooling channel structure is arranged in the reaction area of the bipolar plate.

10. A single cell, characterized in that, Comprising a membrane electrode and the bipolar plate according to claim 8 or 9; The membrane electrode is arranged between two of the bipolar plates.

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