CN116598526A - Polar plate, fuel cell and heat exchange method of fuel cell - Google Patents

Abstract

The application relates to the technical field of fuel cells, in particular to a polar plate, a fuel cell and a heat exchange method of the fuel cell. The polar plate includes: the electrode plate body is provided with a first surface and a second surface, the first surface and the second surface are respectively positioned at two sides of the electrode plate body, the first surface is provided with a reaction zone, and the reaction zone is used for providing a space for carrying out electrochemical reaction; the heat exchange flow field is arranged on the second surface, the heat exchange flow field comprises an inlet area and a heat exchange area, the projection of the reaction area along the thickness direction of the polar plate body is positioned in the range of the heat exchange area, and a heat exchange medium flows from the inlet area to the heat exchange area and exchanges heat with the polar plate body to adjust the temperature of the reaction area; the heat exchange flow field further comprises a transition area and an air chamber area, the inlet area is communicated with the heat exchange area through the transition area, and the air chamber area is located above the heat exchange area and connected with the transition area, so that bubbles in a heat exchange medium are lifted by buoyancy in the transition area and enter the air chamber area, and the problem that the bubbles cause local overheating of the reaction area is solved.

Description

Polar plate, fuel cell and heat exchange method of fuel cell

Technical Field

The application relates to the technical field of fuel cells, in particular to a polar plate, a fuel cell and a heat exchange method of the fuel cell.

Background

Fuel cells are typically formed by stacking a plurality of fuel cells, each of which is supplied with a reactant gas (e.g., hydrogen or air) to perform an electrochemical reaction and generate an electric current. Each fuel cell unit comprises two polar plates, one surface of each polar plate facing the interior of the fuel cell unit is provided with a reaction zone, the reaction zone is provided with a plurality of grooves which are arranged at intervals, the grooves are used as gas flow channels for reaction gas to flow, and electrochemical reaction mainly occurs near the reaction zone.

Heat is generated during the electrochemical reaction to raise the temperature, which affects the performance and service life of the fuel cell. In order to keep proper temperature, at present, a heat exchange flow field is arranged on one surface of the polar plate facing the outside of the battery cell, a heat exchange medium flows in the heat exchange flow field, and the temperature of the fuel cell is reduced in a heat exchange mode. The corresponding positions of the gas flow channels are bulges on one surface of each polar plate, which is away from the inside of the fuel cell unit, and grooves are arranged between two adjacent gas flow channels and can be used as heat exchange flow channels for heat exchange medium to flow.

In actual use, the phenomenon of heat exchange flow channel blockage exists, and the heat exchange flow channel blockage easily causes local overheating of the fuel cell monomer, thereby influencing the performance and the service life of the fuel cell. How to avoid the blockage of the heat exchange flow passage and prevent local overheating is a technical problem to be solved in the field.

Disclosure of Invention

According to research, bubbles are sometimes mixed in the heat exchange medium, and the bubbles easily block the heat exchange flow passage after entering the heat exchange flow passage.

The application aims to provide a polar plate, a fuel cell and a heat exchange method of the fuel cell, which can be used for relieving the problem that a heat exchange flow channel is blocked by bubbles so as to avoid local overheating of the fuel cell.

Embodiments of the present application are implemented as follows:

in a first aspect, an embodiment of the present application provides a plate for a fuel cell unit, the plate including:

the electrode plate body is provided with a first surface and a second surface, the first surface and the second surface are respectively positioned at two sides of the electrode plate body, the first surface is provided with a reaction zone, and the reaction zone is used for providing a space for carrying out electrochemical reaction;

the heat exchange flow field is arranged on the second surface, the heat exchange flow field comprises an inlet area and a heat exchange area, the projection of the reaction area along the thickness direction of the polar plate body is positioned in the range of the heat exchange area, and the heat exchange medium flows from the inlet area to the heat exchange area and exchanges heat with the polar plate body to regulate the temperature of the reaction area;

the heat exchange flow field further comprises a transition area and a gas chamber area, the inlet area is communicated with the heat exchange area through the transition area, and the gas chamber area is located above the heat exchange area and connected with the transition area, so that bubbles in the heat exchange medium are lifted in the transition area by buoyancy and enter the gas chamber area.

In the technical scheme provided by the application, the heat exchange area is an area corresponding to the reaction area, the air chamber area is staggered with the reaction area, and as the air bubbles in the heat exchange medium mainly enter the air chamber area of the heat exchange flow field, the content of the air bubbles in the heat exchange medium entering the heat exchange area is greatly reduced, the influence of the air bubbles on the temperature of the reaction area is small, the flow channel of the heat exchange area is not easy to be blocked by the air bubbles, and the problem of local overheating caused by the blocking of the heat exchange flow channel by the air bubbles is solved.

In one embodiment of the present application, the electrode plate further includes:

and one end of the exhaust runner is connected with the air chamber area, and the other end of the exhaust runner is connected with an exhaust manifold of the fuel cell.

In the technical scheme, the air bubbles in the air chamber area are independently discharged through the exhaust runner, so that the air bubbles are further prevented from entering the heat exchange area to cause blockage.

In one embodiment of the present application, the exhaust runner is connected to one end of the exhaust manifold of the fuel cell higher than one end of the exhaust runner connected to the plenum.

In the above technical scheme, the inlet of the exhaust runner is lower than the outlet, the outlet of the exhaust runner is positioned above the liquid level of the heat exchange medium in the heat exchange flow field, and bubbles with smaller density are easy to rise along the exhaust runner and discharge out of the air chamber.

In one embodiment of the application, the plenum region is conically shaped with the larger end of the cone being connected to the transition region and the smaller end of the cone being connected to the exhaust manifold of the fuel cell.

In the technical scheme, bubbles easily enter the air chamber area from the conical larger end and are converged towards the smaller end, so that the bubbles can be conveniently collected and discharged.

In one embodiment of the application, the heat exchange flow field further comprises:

the first outlet area is communicated with the heat exchange area so as to enable heat exchange medium in the heat exchange area to flow out;

and the second outlet area is communicated with the air chamber area and is used for allowing bubbles in the air chamber area to flow out.

In the technical scheme, the corresponding outlet areas are respectively arranged on the heat exchange area and the air chamber area, the content of the heat exchange area and the content of the air chamber area are independently discharged, so that the influence of bubbles on the heat exchange area is further avoided, the first outlet area and the second outlet area are further conveniently controlled in an opening and closing manner or in a flow control manner, the internal pressure of the heat exchange flow field is conveniently adjusted, the pressure outlet is conveniently switched, and the collection and the discharge of bubbles are conveniently controlled.

In a second aspect, an embodiment of the present application provides a fuel cell including:

a plurality of battery cells arranged in a stack, each of the battery cells comprising the electrode plate of any one of the first aspects;

a first discharge manifold communicating with the heat exchange region of the plate to discharge a heat exchange medium;

a second discharge manifold communicating with the plenum region of the plate to discharge bubbles;

a first valve for regulating the flow of the first exhaust manifold;

and a second valve for regulating the flow of the second exhaust manifold.

In the fuel cell provided by the embodiment of the application, the heat exchange area corresponding to the reaction area of each cell unit has the characteristics of difficult occurrence of blockage and higher heat exchange efficiency, and each cell unit is difficult to generate local overheating, so that the fuel cell has better performance and longer service life.

In a third aspect, an embodiment of the present application provides a heat exchange method for a fuel cell, which is used for the fuel cell in the second aspect, and the heat exchange method includes:

separating: opening a first valve to open a first discharge manifold, so that a heat exchange medium flows from an inlet region to a heat exchange region through a transition region in a heat exchange flow field of each polar plate, and at least part of bubbles in the heat exchange medium rise under the action of buoyancy and enter a gas chamber region above the heat exchange region from the transition region;

and (3) discharging: the second valve is opened to open the second discharge manifold to allow the air bubbles in the plenum area to be discharged from the second discharge manifold.

In the heat exchange method provided by the application, in the process of flowing and exchanging heat of the heat exchange medium, bubbles in the heat exchange medium are separated and rise in the transition area and enter the air chamber area, so that the influence of the bubbles on the heat exchange area is relieved, the heat exchange effect of the heat exchange area is better, the heat exchange area is not easy to be blocked to cause local overheating, and the safety is higher; meanwhile, the air bubbles concentrated in the air chamber area are discharged through the discharging step, so that the gas in the heat exchange flow field is reduced, and the subsequent air bubble collection is ensured. Therefore, the application can effectively relieve the influence of bubbles on the heat exchange area and the reaction area and avoid the problem of local overheating of the fuel cell by alternately or simultaneously carrying out the separation step and the discharge step.

In one embodiment of the application, during the discharging step, the first valve is adjusted to reduce the flow of the first discharge manifold.

In the technical scheme, the flow of the first discharge manifold is reduced by adjusting the first valve, so that the liquid level of a heat exchange medium in the heat exchange flow field is quickly increased or the internal pressure of the heat exchange flow field is increased, bubbles are quickly extruded from the air chamber area to the second discharge manifold, and the speed of discharging the bubbles is accelerated.

In one embodiment of the application, during the separating step, adjusting the second valve to reduce the flow of the second exhaust manifold;

and after the air chamber area stores a certain volume of air bubbles, performing the discharging step, and adjusting the second valve in the discharging step to increase the flow of the second discharging manifold.

In the technical scheme, the flow of the second discharge manifold is reduced in the separation step, so that most of heat exchange medium mainly flows along the inlet area, the transition area, the heat exchange area and the second outlet area, and a small part of heat exchange medium pushes bubbles to flow towards the air chamber area and the first outlet area, so that on one hand, a good heat exchange effect is ensured, on the other hand, the bubbles can be well collected, part of the bubbles can be discharged in the separation step, and the time for the air chamber area to reach the set bubble storage capacity is prolonged; and in the discharging step, the flow of the second discharging manifold is increased, so that the flow area can be increased to prevent larger bubbles from blocking the opening of the second valve, the discharging effect is improved, and the bubble discharging is accelerated.

In one embodiment of the application, in the separating step, the heat exchange flow field has a first internal pressure; the pressure threshold of the second valve is greater than the first internal pressure.

In the above technical scheme, since the second valve is in a closed or semi-closed state to reduce the flow in the separation step, the pressure applied to the second valve in the separation step is larger, and the pressure threshold of the second valve is set to be larger than the first internal pressure, so that the second valve is prevented from being damaged or invalid due to overlarge pressure bearing in the separation step, the larger proportion of heat exchange medium in the heat exchange flow field entering the heat exchange area is ensured, and the heat exchange effect is further ensured.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic top view of a fuel cell according to an embodiment of the present application;

FIG. 2 is a schematic cross-sectional view of a fuel cell according to an embodiment of the present application;

FIG. 3 is a schematic top view of a plate according to an embodiment of the present application;

FIG. 4 is a schematic view of a first surface of a plate according to an embodiment of the present application;

FIG. 5 is a schematic view of a second surface of a plate according to an embodiment of the present application;

fig. 6 is a schematic flow chart of a heat exchange method of a fuel cell according to an embodiment of the present application.

Icon: 1000-fuel cell, 100-cell, 101-plate, 1011-first surface, 1012-second surface, 102-diffusion reaction layer, 200-liquid supply manifold, 301-first discharge manifold, 302-second discharge manifold, 401-first valve, 402-second valve, 500-reaction zone, 600-heat exchange flow field, 601-inlet zone, 602-transition zone, 603-heat exchange zone, 604-plenum zone, 6051-first outlet zone, 6052-second outlet zone, 606-exhaust runner.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. The components of the embodiments of the present application generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

The fuel cell 1000 is a chemical device that directly converts chemical energy of fuel into electric energy. As shown in fig. 1, the fuel cell 1000 includes a plurality of stacked battery cells 100. As shown in fig. 2, each battery cell 100 includes two electrode plates 101.

As shown in fig. 3, an embodiment of the present application provides a pole plate 101, where the pole plate 101 includes a pole plate 101 body, the pole plate 101 body has a first surface 1011 and a second surface 1012, and the first surface 1011 and the second surface 1012 are respectively located at two sides of the pole plate 101 body.

As shown in fig. 4, the first surface 1011 is a surface facing the inside of the battery cell 100, the first surface 1011 is provided with a gas flow field, the gas flow field comprises a reaction zone 500, and the reaction zone 500 is provided with a plurality of gas flow channels so that the reaction gas is transported along the plurality of gas flow channels.

The battery cell 100 generally further includes a diffusion reaction layer 102, where the diffusion reaction layer 102 generally includes two gas diffusion layers, two catalyst layers and a proton exchange membrane, the two catalyst layers are respectively disposed on two sides of the proton exchange membrane, and the two gas diffusion layers are respectively disposed on surfaces of the two catalyst layers.

In the embodiment of the present application, at least the projection of the catalyst layer in the diffusion reaction layer 102 along the thickness direction of the body of the polar plate 101 is located in the reaction zone 500, and the reaction gas diffuses into the diffusion reaction layer 102 during the process of transferring in the gas flow channel of the reaction zone 500, and generates an electrochemical reaction through the action of the catalyst layer. That is, at least the catalyst layer in the diffusion reaction layer 102 is entirely located in the space formed by the reaction regions 500 of the two electrode plates 101, in other words, the reaction regions 500 serve to provide a space for performing an electrochemical reaction.

There are various molding methods of the gas flow channels, for example, a plurality of separation plates are disposed on the surface of the electrode plate 101 body, and a plurality of heat exchange flow channels are separated in the reaction zone 500 by using the plurality of separation plates. For another example, a plurality of heat exchange channels are formed on the surface of the electrode plate 101 body by stamping or etching.

As shown in fig. 5, the second surface 1012 is a surface facing the outside of the battery cell 100, and the second surface 1012 is provided with a heat exchange flow field 600, and the heat exchange flow field 600 includes an inlet region 601, a transition region 602, a heat exchange region 603, and a gas chamber region 604.

The fuel cell 1000 generally has a liquid supply manifold 200, as shown in fig. 2, the liquid supply manifold 200 being a channel inside the fuel cell 1000 for supplying a heat exchange medium to the heat exchange flow field 600. The liquid supply manifold 200 may be an integral structure, for example, an integral pipe is used as the liquid supply manifold 200, through holes penetrating in the thickness direction are respectively provided in each structural layer (such as the polar plate 101 and the proton exchange membrane) of the fuel cell 1000, the liquid supply manifold 200 sequentially passes through the through holes of each layer, and openings are provided on the side wall of the liquid supply manifold 200 to communicate with the heat exchange flow field 600. Alternatively, the liquid supply manifold 200 may be a split structure, for example, through holes penetrating in the thickness direction are provided in each structural layer (such as the polar plate 101 and the proton exchange membrane) of the fuel cell 1000, and each structural layer is stacked and assembled in sequence and sealed by a gasket, so that the through holes of each structural layer are connected in sequence to form the liquid supply manifold 200, and the side wall of the liquid supply manifold 200 has an opening (such as an opening provided on the side wall of the through hole of the gasket or the polar plate 101) so as to communicate with the heat exchange flow field 600.

The inlet region 601 of the heat exchange flow field 600 is a through hole provided on the plate 101 for the fluid supply manifold 200 to pass through or for forming the fluid supply manifold 200. From the inlet region 601, the heat exchange medium can enter the heat exchange flow field 600.

The inlet area 601 and the heat exchange area 603 are communicated through a transition area 602, the heat exchange area 603 is provided with a plurality of heat exchange flow channels, and after the heat exchange medium enters the heat exchange flow field 600 from the inlet area 601, the heat exchange medium enters the heat exchange area 603 through the transition area 602, so that the heat exchange medium is approximately uniformly distributed in the plurality of heat exchange flow channels and flows along the heat exchange flow channels.

The plenum region 604 is located above the heat exchange region 603, and the plenum region 604 is connected to the transition region 602. The vertical direction refers to the vertical direction, namely the gravity direction. As the heat exchange medium passes through the transition zone 602, the bubbles in the heat exchange medium rise under buoyancy and enter the upper plenum zone 604.

The projection of the reaction zone 500 along the thickness direction of the electrode plate 101 body is located within the range of the heat exchange zone 603, that is, the position of the reaction zone 500 corresponds to the position of the heat exchange zone 603, and the area of the heat exchange zone 603 is greater than or equal to the area of the reaction zone 500.

Since heat generated by the electrochemical reaction mainly acts on the reaction zone 500 of the plate 101, and the heat exchange flow path of the reaction zone 500 is a structure that is easily blocked by bubbles, the reaction zone 500 is a region where the plate 101 is easily overheated.

In the embodiment of the application, the air bubbles in the heat exchange medium mainly enter the air chamber region 604 of the heat exchange flow field 600, the content of the air bubbles in the heat exchange medium entering the heat exchange region 603 is greatly reduced, the heat exchange flow channel in the heat exchange region 603 is not easy to be blocked by the air bubbles, and the heat exchange medium can smoothly flow in the heat exchange flow channel, so that the heat exchange region 603 keeps higher heat exchange efficiency, wherein the projection of the reaction region 500 along the thickness direction of the polar plate 101 body is positioned in the range of the heat exchange region 603, so that the heat exchange medium can quickly carry away the heat of the reaction region 500, and the problem of local overheating caused by the blocking of the heat exchange flow channel by the air bubbles in the prior art is solved.

It should be noted that, the technical solution provided by the embodiment of the present application is not only suitable for the scenario of reducing the temperature of the polar plate 101, but also suitable for the scenario of increasing the temperature of the polar plate 101 through the heat exchange medium. In the heating scene, the problem that the local temperature is too low due to the blocking of the heat exchange flow channel by the air bubble can be relieved, so that the whole area of the reaction zone 500 is at a proper working temperature.

In some embodiments, plenum region 604 and heat exchange region 603 share an outlet region, and the gas bubbles bypass heat exchange region 603 and flow out of heat exchange flow field 600 through plenum region 604, so as to prevent the gas bubbles from blocking the heat exchange flow channels of heat exchange region 603, resulting in localized overheating.

In other embodiments, plenum region 604 and heat exchange region 603 are each provided with an outlet region.

As shown in fig. 5, the heat exchange flow field 600 further includes a first outlet region 6051 and a second outlet region 6052. The first outlet zone 6051 communicates with the heat exchange zone 603 for outflow of the heat exchange medium from the heat exchange zone 603. The second outlet region 6052 communicates with the plenum region 604 to supply air bubbles to the plenum region 604.

The contents of plenum region 604 may include a mixture of heat exchange medium and air bubbles; when the bubble content is high, the heat exchange medium in the air chamber area 604 may be extruded by the air, so that the air chamber area 604 is full of air; while in the absence of bubbles in the heat exchange medium, plenum 604 may also be filled with the heat exchange medium. Thus, the content exiting the plenum region 604 may be a mixture of heat exchange medium and bubbles, gas only, or heat exchange medium only.

By providing the heat exchange area 603 and the air chamber area 604 with corresponding outlet areas, respectively, the contents of the heat exchange area 603 and the contents of the air chamber area 604 are discharged independently, thereby further avoiding the influence of air bubbles on the heat exchange area 603, for example, avoiding the bad influence of the occurrence of air bubbles blocking the outlet areas on the heat exchange medium flow of the heat exchange area 603.

In addition, by performing opening and closing control or flow control on the first outlet region 6051 and the second outlet region 6052, respectively, the internal pressure of the heat exchange flow field 600 can be adjusted, and the pressure outlet can be switched, which is advantageous in controlling the collection and discharge of bubbles.

In the normal operation state of the fuel cell 1000, the flow rate of the first outlet region 6051 is increased, the flow rate of the second outlet region 6052 is reduced, the flow rate of the heat exchange medium flowing out of the air chamber region 604 is reduced, the flow rate of the heat exchange medium flowing out of the heat exchange region 603 is increased, and the heat exchange effect of the reaction region 500 is good.

In some embodiments, the second outlet region 6052 is positioned higher than the first outlet region 6051. That is, the second outlet region 6052 is higher than the first outlet region 6051 in the gravitational direction, so that bubbles floating above the heat exchange flow field 600 are easily discharged. In the prior art, the outlets of the heat exchange flow fields are generally located at the middle position, so that the distance between each heat exchange flow channel and each outlet is relatively balanced, and bubbles are difficult to completely discharge.

The fuel cell 1000 also typically has an exhaust manifold, which is a channel internal to the fuel cell 1000 for exhausting the heat exchange medium in the heat exchange flow field 600 out of the fuel cell 1000. The exhaust manifold may be an integral structure, for example, an integral pipe is used as the exhaust manifold, through holes penetrating in the thickness direction are respectively provided in each structural layer (such as the polar plate 101 and the proton exchange membrane) of the fuel cell 1000, the exhaust manifold sequentially passes through the through holes of each layer, and openings are provided on the side wall of the exhaust manifold to communicate with the heat exchange flow field 600. Alternatively, the exhaust manifold may be a split structure, for example, through holes penetrating in the thickness direction are provided in each structural layer (such as the electrode plate 101, the proton exchange membrane, etc.) of the fuel cell 1000, and each structural layer is sequentially stacked, assembled and sealed by a gasket, so that the through holes of each structural layer are sequentially connected to form the exhaust manifold, and the side wall of the exhaust manifold has an opening (such as an opening provided in the side wall of the through hole of the gasket or the electrode plate 101) to communicate with the heat exchange flow field 600.

The outlet region of the heat exchange flow field 600 is a through-hole provided in the plate 101 for passing through the exhaust manifold, or the outlet region is for forming the exhaust manifold. The heat exchange medium exits the heat exchange flow field 600 from the outlet region into the exhaust manifold.

In embodiments where the heat exchange flow field 600 includes a first outlet region 6051 and a second outlet region 6052, as shown in fig. 2, the fuel cell 1000 includes a first exhaust manifold 301 and a second exhaust manifold 302. The first exhaust manifold 301 is disposed through the first outlet region 6051, or the first outlet region 6051 is used to form the first exhaust manifold 301. The second exhaust manifold 302 is disposed through the second outlet region 6052, or the second outlet region 6052 is used to form the second exhaust manifold 302.

The heat exchange flow field 600 further includes an exhaust flow channel 606, where the exhaust flow channel 606 is disposed on the second surface 1012, and one end of the exhaust flow channel 606 is connected to the plenum region 604, and the other end is connected to the exhaust manifold of the fuel cell 1000. That is, in embodiments where plenum region 604 and heat exchange region 603 share an outlet, plenum region 604 communicates with the exhaust manifold of the cell through exhaust runner 606; in embodiments where plenum 604 and heat exchange region 603 are provided with outlets, respectively, plenum 604 communicates with first exhaust manifold 301 via exhaust runner 606.

Wherein the exhaust runner 606 is connected to one end of the exhaust manifold of the fuel cell 1000, and is higher than one end of the exhaust runner 606 connected to the plenum region 604. The inlet of the exhaust runner 606 is lower than the outlet, the outlet of the exhaust runner 606 is positioned above the liquid level of the heat exchange medium in the heat exchange flow field 600, and bubbles with smaller density are easy to rise along the exhaust runner 606 and discharge out of the air chamber, so that the bubbles can be completely discharged out of the heat exchange flow field 600.

In some embodiments, plenum region 604 is conically shaped with the larger end of the taper connecting to transition region 602 and the smaller end of the taper connecting to the exhaust manifold of fuel cell 1000. Bubbles tend to enter plenum region 604 from the larger end of the cone and converge toward the smaller end, facilitating the evacuation of the bubbles.

In a second aspect, an embodiment of the present application further provides a fuel cell 1000, as shown in fig. 1, where the fuel cell 1000 includes a plurality of battery cells 100, and the plurality of battery cells 100 are stacked, and each battery cell 100 includes the electrode plate 101 provided in the foregoing embodiment. That is, at least one plate 101 of each battery cell 100 is the plate 101 provided in the above-described embodiment.

The stacking direction of the plurality of battery cells 100 is a horizontal direction, and each of the electrode plates 101 is parallel to a vertical plane such that the gas chamber region 604 is located above the heat exchange region 603.

As shown in fig. 1 and 2, the fuel cell 1000 further includes a first discharge manifold 301, a second discharge manifold 302, a first valve 401, and a second valve 402.

The first exhaust manifold 301 communicates with the heat exchange region 603 of the plate 101, the first valve 401 is used to regulate the flow of the first exhaust manifold 301, when the first valve 401 opens the first exhaust manifold 301, the heat exchange medium can exhaust the heat exchange flow field 600 from the first exhaust manifold 301, and the first valve 401 can control the flow of the first exhaust manifold 301.

The second exhaust manifold 302 communicates with the plenum region 604 of the plate 101, the second valve 402 is configured to regulate the flow of the second exhaust manifold 302, air bubbles are able to exit the heat exchange flow field 600 from the second exhaust manifold 302 when the second valve 402 opens the second exhaust manifold 302, and the second valve 402 is able to control the flow of the second exhaust manifold 302.

In the fuel cell 1000 provided in the embodiment of the present application, each of the battery units 100 includes at least one polar plate 101 in the embodiments of the first aspect, so that the surface of each battery unit 100 has the aforementioned heat exchange flow field 600, which makes the heat exchange area 603 corresponding to the reaction area 500 of each battery unit 100 have the characteristics of difficult blockage and higher heat exchange efficiency, and each battery unit 100 is difficult to generate local overheating, so that the performance of the fuel cell 1000 is better and the service life is longer.

Having described the electrode plate 101 and the fuel cell 1000 of the embodiment of the present application, a heat exchanging method of the fuel cell 1000 will be described below, wherein the foregoing embodiments are referred to for a detailed description.

As shown in fig. 6, the heat exchange method includes:

s1, separating: the first valve 401 is opened to open the first exhaust manifold 301 to allow the heat exchange medium to flow within the heat exchange flow field 600 of each plate 101 from the inlet region 601 through the transition region 602 toward the heat exchange region 603, thereby allowing at least a portion of the air bubbles in the heat exchange medium to rise under buoyancy and from the transition region 602 into the plenum region 604 above the heat exchange region 603.

S2, discharging: the second valve 402 is opened to open the second exhaust manifold 302, allowing the bubbles of the plenum 604 to be exhausted from the second exhaust manifold 302.

In some embodiments, step S1 and step S2 may be performed simultaneously, and the heat exchange medium exchanges heat with the plate 101 to reduce the temperature of the reaction zone 500 while allowing bubbles to be discharged through the transition zone 602 and the plenum zone 604.

In other embodiments, step S2 may be performed first, and then step S1 may be performed, where the gas in the gas chamber region 604 is evacuated, and the gas chamber region 604 is filled with a heat exchange medium, so as to prepare for subsequent bubble accommodation. Illustratively, the S2 bleed step is performed while the fuel cell 1000 is in an idle, chiller, or standby state in preparation for subsequent heat exchange during the operating state of the fuel cell 1000.

In still other embodiments, step S1 and step S2 may be performed first, and when the heat exchange medium exchanges heat with the plate 101 to reduce the temperature of the reaction zone 500, the bubbles enter the gas chamber region 604 through the transition region 602 for storage, and finally the bubbles stored in the gas chamber region 604 are discharged. That is, in the S1 separation step, the first valve 401 is opened to open the first discharge manifold 301, and the second valve 402 is closed to block the second discharge manifold 302.

Illustratively: when the fuel cell 1000 is in an operation state, an S1 separation step is performed, while a heat exchange medium flows in the heat exchange flow field 600 along the inlet area 601, the transition area 602, the heat exchange area 603 and the outlet area in sequence, the reaction area 500 is at a proper working temperature through heat exchange between the heat exchange medium and the polar plate 101; while the less dense bubbles in the heat exchange medium are buoyantly lifted in the transition zone 602 and are stored under fluid propulsion from the transition zone 602 into the plenum zone 604 above the heat exchange zone 603. After a certain amount of bubbles are stored in the plenum 604, an S2 discharging step is performed.

Optionally, the discharging step further comprises: the length of time that the air chamber region 604 stores a certain amount of air bubbles is set according to the air content in the unit volume of the heat exchange medium, for example, the length of time that the air chamber region 604 is just full of air, and the length of time is set for convenience of description. After the time for performing the S1 separation step reaches the set period, the S2 draining step is performed. Preferably, the set duration is less than the duration that the plenum region 604 is just full of gas.

Alternatively, a detection device may be provided in the plenum region 604 to acquire the bubble storage amount of the plenum region 604. For example, a liquid level sensor is disposed in the plenum area 604, the liquid level sensor is located near the upper and lower boundary between the plenum area 604 and the heat exchange area 603, and when the liquid level of the heat exchange medium is lower than the liquid level sensor, the step S2 of discharging is performed.

When the separation step S1 is performed, the second valve 402 may not be completely closed and block the second exhaust manifold 302, or the second valve 402 may be adjusted to reduce the flow of the second exhaust manifold 302, so that most of the heat exchange medium mainly flows along the inlet area 601, the transition area 602, the heat exchange area 603 and the second outlet area 6052, and a small part of the heat exchange medium pushes the air bubbles to flow towards the air chamber area 604 and the first outlet area 6051, so that on one hand, a better heat exchange effect is ensured, on the other hand, air bubbles can be better collected, and part of the air bubbles can be discharged during the separation step S1, so that the time for the air chamber area 604 to reach the set air bubble storage capacity is prolonged.

After the plenum 604 stores a certain amount of bubbles, a discharging step is performed, in which the second valve 402 is adjusted to increase the flow rate of the second discharge manifold 302, so as to prevent the larger bubbles from blocking the opening of the second valve 402, and improve the air discharging effect.

Since the second valve 402 is in a closed or semi-closed state to reduce the flow rate in the S1 separation step, the second valve 402 is subjected to a pressure greater than that in the S2 discharge step in the S1 separation step. It is assumed that in the S1 separation step, the heat exchange flow field 600 has a first internal pressure, and the pressure threshold of the second valve 402 is set to be greater than the first internal pressure, so as to prevent the second valve 402 from being damaged or failed due to excessive pressure bearing in the S1 separation step. Alternatively, if the maximum internal pressure of the heat exchange flow field 600 is greater than the first internal pressure, the pressure threshold of the second valve 402 may be set to be greater than the maximum internal pressure of the heat exchange flow field 600.

In the step S2 of discharging, when the second valve 402 is opened to open the second discharge manifold 302, the first valve 401 is adjusted to reduce the flow rate of the first discharge manifold 301, so that the liquid level of the heat exchange medium in the heat exchange flow field 600 is rapidly raised or the internal pressure is increased, so that the bubbles are rapidly extruded from the air chamber region 604 to the second discharge manifold 302, and the speed of discharging the bubbles is increased. Here, "reducing the flow rate of the first discharge manifold 301" means reducing or zeroing the flow rate of the first discharge manifold 301.

Since the first valve 401 is in a closed or semi-closed state to reduce the flow rate in the S2 discharging step, the first valve 401 receives a pressure greater than that in the S1 discharging step. It is assumed that the second internal pressure is present in the heat exchange flow field 600 during the S2 exhaust step, and the pressure threshold of the first valve 401 is set to be greater than the second internal pressure so as to prevent the first valve 401 from being damaged or failed due to excessive pressure during the first valve 401S2 exhaust step. Alternatively, if the maximum internal pressure of the heat exchange flow field 600 is greater than the second internal pressure, the pressure threshold of the first valve 401 may be set to be greater than the maximum internal pressure of the heat exchange flow field 600.

As shown in fig. 1 to 6, an embodiment of the present application provides a fuel cell 1000, the fuel cell 1000 including a plurality of cells 100, a liquid supply manifold 200, a first discharge manifold 301, and a second discharge manifold 302. The plurality of battery cells 100 are stacked along a horizontal direction, each battery cell 100 comprises two polar plates 101, the polar plates 101 are approximately parallel to a vertical plane, each polar plate 101 is provided with a first surface 1011 and a second surface 1012, the first surface 1011 is an inner wall of the battery cell 100 where the polar plate 101 is located, the first surface 1011 is provided with a reaction zone 500, the reaction zone 500 is used for providing a space for performing electrochemical reaction, the second surface 1012 is an outer wall of the battery cell 100 where the polar plate 101 is located, the second surface 1012 is provided with a heat exchange flow field 600, the heat exchange flow field 600 comprises an inlet zone 601, a transition zone 602, a heat exchange zone 603, a gas chamber zone 604, a first outlet zone 6051 and a second outlet zone 6052, wherein the inlet zone 601, the transition zone 602, the heat exchange zone 603 and the first outlet zone 6051 are connected in sequence, the gas chamber zone 604 is separated from the heat exchange zone 603, the gas chamber zone 604 is located above the heat exchange zone 603, and the gas chamber zone 604 is connected between the transition zone 602 and the second outlet zone 6052. The liquid supply manifold 200, the first discharge manifold 301, and the second discharge manifold 302 extend in the stacking direction of the plurality of battery cells 100, the liquid supply manifold 200 communicates with the inlet region 601 of each heat exchange flow field 600, the first discharge manifold 301 communicates with the first outlet region 6051 of each heat exchange flow field 600, and the second discharge manifold 302 communicates with the second outlet region 6052 of each heat exchange flow field 600, respectively.

The heat exchange method of the fuel cell 1000 according to the embodiment of the present application is as follows.

In the operation state of the fuel cell 1000, the S1 separation step is performed:

opening the first valve 401 to open the first discharge manifold 301, closing the second valve 402 to block the second discharge manifold 302, and introducing a heat exchange medium into each heat exchange flow field 600 through the liquid supply manifold 200 to enable the heat exchange medium to flow along paths of an inlet area 601, a transition area 602, a heat exchange area 603 and a first outlet area 6051 in each heat exchange flow field 600, wherein bubbles in the heat exchange medium rise under the action of buoyancy force, and enter a gas chamber area 604 above the heat exchange area 603 from the transition area 602 for storage.

After the air bubbles stored in the air chamber region 604 reach a certain volume, or when the fuel cell 1000 is in an idle, cold or standby state, the step S2 of discharging is performed:

closing the first valve 401 blocks the first discharge manifold 301, the second valve 402 opens the second discharge manifold 302, and the heat exchange medium is introduced into each heat exchange flow field 600 through the liquid supply manifold 200, the liquid level of the heat exchange medium in the heat exchange flow fields 600 is raised or the liquid level is unchanged, the internal pressure is increased, and the air bubbles stored in the air chamber region 604 are extruded from the second outlet region 6052 and discharged through the second discharge manifold 302.

In the foregoing embodiments, the descriptions of the embodiments are focused on, and the portions of one embodiment that are not described in detail in the foregoing embodiments may be referred to in the foregoing detailed description of other embodiments, which are not described herein again.

Meanwhile, the present application uses specific words to describe embodiments of the present application. Reference to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic is associated with at least one embodiment of the application. Thus, it should be emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various positions in this specification are not necessarily referring to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of the application may be combined as suitable.

Similarly, it should be appreciated that in order to simplify the present disclosure and thereby facilitate an understanding of one or more embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure. This method of disclosure, however, is not intended to imply that more features than are required by the subject application. Indeed, less than all of the features of a single embodiment disclosed above.

It should be noted that: like reference numerals and letters designate like items in the drawings of the present application, and thus once an item is defined in one drawing, no further definition or explanation thereof is necessary in the subsequent drawings.

In the description of the present application, it should be noted that, if the terms "center", "upper", "lower", "left", "right", "inner", "outer", etc. indicate an azimuth or a positional relationship based on that shown in the drawings, or an azimuth or a positional relationship that the product of the application is conventionally put in use, it is merely for convenience of describing the present application and simplifying the description, and it is not indicated or implied that the apparatus or element referred to must have a specific azimuth, be configured and operated in a specific azimuth, and thus it should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like in the description of the present application, if any, are used for distinguishing between the descriptions and not necessarily for indicating or implying a relative importance.

In the description of the present application, it should also be noted that, unless explicitly stated and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" should be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

Each patent, patent application publication, and other material, such as articles, books, specifications, publications, documents, etc., cited herein is hereby incorporated by reference in its entirety except for any application history file that is inconsistent or otherwise conflict with the present disclosure, which places the broadest scope of the claims in this application (whether presently or after it is attached to this application). It is noted that the description, definition, and/or use of the term in the appended claims controls the description, definition, and/or use of the term in this application if there is a discrepancy or conflict between the description, definition, and/or use of the term in the appended claims.

Claims (10)

1. A plate for a fuel cell, the plate comprising:

the electrode plate body is provided with a first surface and a second surface, the first surface and the second surface are respectively positioned at two sides of the electrode plate body, the first surface is provided with a reaction zone, and the reaction zone is used for providing a space for carrying out electrochemical reaction;

the heat exchange flow field is arranged on the second surface, the heat exchange flow field comprises an inlet area and a heat exchange area, the projection of the reaction area along the thickness direction of the polar plate body is positioned in the range of the heat exchange area, and a heat exchange medium flows from the inlet area to the heat exchange area and exchanges heat with the polar plate body to regulate the temperature of the reaction area;

the heat exchange flow field further comprises a transition area and a gas chamber area, the inlet area is communicated with the heat exchange area through the transition area, and the gas chamber area is located above the heat exchange area and connected with the transition area, so that bubbles in the heat exchange medium are lifted in the transition area by buoyancy and enter the gas chamber area.

2. The plate of claim 1, further comprising:

and one end of the exhaust runner is connected with the air chamber area, and the other end of the exhaust runner is connected with an exhaust manifold of the fuel cell.

3. The plate of claim 2 wherein the exhaust runner is connected to one end of the exhaust manifold of the fuel cell higher than the end of the exhaust runner connected to the plenum.

4. The plate of claim 1 wherein the plenum region is conically shaped with a larger end of the cone connecting the transition region and a smaller end of the cone connecting the exhaust manifold of the fuel cell.

5. The plate of any one of claims 1-4, wherein the heat exchange flow field further comprises:

the first outlet area is communicated with the heat exchange area so as to enable heat exchange medium in the heat exchange area to flow out;

and the second outlet area is communicated with the air chamber area and is used for allowing bubbles in the air chamber area to flow out.

6. A fuel cell, characterized by comprising:

a plurality of battery cells arranged in a stack, each of the battery cells comprising the electrode plate of any one of claims 1-5;

a first discharge manifold communicating with the heat exchange region of the plate to discharge a heat exchange medium;

a second discharge manifold communicating with the plenum region of the plate to discharge bubbles;

a first valve for regulating the flow of the first exhaust manifold;

and a second valve for regulating the flow of the second exhaust manifold.

7. A heat exchange method of a fuel cell for the fuel cell according to claim 6, characterized by comprising:

separating: opening a first valve to open a first discharge manifold, so that a heat exchange medium flows from an inlet region to a heat exchange region through a transition region in a heat exchange flow field of each polar plate, and at least part of bubbles in the heat exchange medium rise under the action of buoyancy and enter a gas chamber region above the heat exchange region from the transition region;

and (3) discharging: the second valve is opened to open the second discharge manifold to allow the air bubbles in the plenum area to be discharged from the second discharge manifold.

8. The method of heat exchange for a fuel cell according to claim 7, wherein in the step of exhausting, the first valve is adjusted to reduce the flow rate of the first exhaust manifold.

9. The heat exchange method of a fuel cell according to claim 7 or 8, wherein in the separation step, the second valve is adjusted to reduce the flow rate of the second discharge manifold;

and after the air chamber area stores a certain volume of air bubbles, performing the discharging step, and adjusting the second valve in the discharging step to increase the flow of the second discharging manifold.

10. The heat exchange method of a fuel cell according to claim 9, wherein in the separating step, the heat exchange flow field has a first internal pressure;

the pressure threshold of the second valve is greater than the first internal pressure.