Components for thermal management of fuel cells

Abstract

The present disclosure relates to an assembly for thermal management of a fuel cell. A fuel cell assembly is provided that includes a plate assembly having an anode inlet, a cathode inlet, a first coolant inlet, and a second coolant inlet. The first coolant inlet is positioned adjacent to the anode inlet on the first plate side. The second coolant inlet is positioned adjacent to the cathode inlet on the second plate side. The inlet is arranged so that the coolant affects the reactant temperature at the anode inlet and the cathode inlet to promote a uniform hydration distribution of the membrane formed during fuel cell operation. The fuel cell assembly may include a hydrogen channel, an oxygen channel, and a coolant channel. The coolant channel may extend between the hydrogen channel and the oxygen channel to extract heat from the hydrogen and oxygen flowing through the hydrogen channel and the oxygen channel, and to allow the hydrogen and oxygen to be close enough to each other for a chemical reaction between them.

Description

Technical Field

[0001] The present disclosure relates to systems for assisting in managing thermal conditions within a fuel cell stack. Background Art

[0002] A vehicle such as a fuel cell vehicle may include an energy storage device such as a fuel cell stack to power components of the vehicle. The fuel cell stack may be integrated with a system for assisting in managing vehicle performance and fuel cell stack operation. As described herein, a system or component may assist in managing the thermal condition of the fuel cell stack. Summary of the invention

[0003] A fuel cell assembly includes a plate assembly having an anode inlet, a cathode inlet, a first coolant inlet, and a second coolant inlet. The first coolant inlet is positioned adjacent to the anode inlet on the first plate side. The second coolant inlet is positioned adjacent to the cathode inlet on the second plate side. The inlets are arranged so that the coolant affects the reactant temperature at the anode inlet and the cathode inlet to promote the formation of a uniform hydration distribution of the membrane during the operation of the fuel cell. The fuel cell assembly may include a hydrogen channel, an oxygen channel, and a coolant channel. The hydrogen channel may extend between the anode inlet and the anode outlet disposed on the second plate side. The oxygen channel may extend between the cathode inlet and the cathode outlet disposed on the first plate side. The coolant channel may extend between the first coolant inlet and the coolant outlet. The coolant channel may extend between the hydrogen channel and the oxygen channel to absorb heat from the hydrogen and oxygen flowing through the hydrogen channel and the oxygen channel, and to bring the hydrogen and oxygen close enough to each other for a chemical reaction between the hydrogen and oxygen. The fuel cell assembly may include a first coolant outlet disposed on the third plate side, a second coolant outlet disposed on the fourth plate side, and a coolant flow field that fluidly connects the coolant inlet and the coolant outlet. The coolant inlet and the coolant outlet may be arranged together so that the flow of the coolant from the coolant inlet to the coolant outlet is evenly distributed in the coolant flow field. The coolant flow field may include a central area with one or more columns to affect the turbulence of the coolant flow, thereby promoting a uniform coolant flow from the coolant inlet to the coolant outlet. The plate assembly may also include two plates, each plate including a pair of serpentine walls, a hydrogen channel and an oxygen channel, the pair of serpentine walls being arranged together to form two separate coolant channels between the serpentine walls, the hydrogen channel extending substantially perpendicular to a portion of one of the coolant channels and extending between the anode inlet and the anode outlet, the oxygen channel extending substantially perpendicular to a portion of one of the coolant channels and extending between the cathode inlet and the cathode outlet. The channels may be arranged together so that the hydrogen channel and the oxygen channel are adjacent to each other to promote the chemical reaction between the hydrogen channel and the oxygen channel, and the coolant flowing through the coolant channel is thermally connected to the hydrogen and oxygen flowing through the hydrogen channel and the oxygen channel. The fuel cell assembly may also include a first pressure regulator, a second pressure regulator, and a third pressure regulator. The first pressure regulator can control the first coolant flow pressure at the first coolant inlet. The second pressure regulator can control the second coolant flow pressure at the second coolant inlet. The third pressure regulator can control the third coolant flow pressure at the first coolant outlet. The pressure regulator can be adjusted to promote a constant coolant flow from the coolant inlet to the coolant outlet. The arrangement of the inlet can affect the reactant temperature at the anode inlet and the cathode inlet so that the reactant temperature is between sixty degrees Celsius and seventy degrees Celsius.

[0004] A fuel cell plate assembly includes a hydrogen channel, an oxygen channel, a first coolant channel configuration, and a second coolant channel configuration. The hydrogen channel extends from the anode inlet to the anode outlet. The oxygen channel extends from the cathode inlet to the cathode outlet. The first coolant channel configuration and the second coolant channel configuration include a coolant inlet and a coolant outlet, respectively. The anode inlet and the cathode outlet are positioned on the first plate side, the cathode inlet and the anode outlet are positioned on the second plate side, each coolant inlet is positioned on the third plate side, and each coolant outlet is positioned on the fourth plate side, so that the coolant in the first coolant channel configuration and the second coolant channel configuration flows along a direction substantially perpendicular to a portion of the hydrogen flowing in the hydrogen channel and a portion of the oxygen flow in the oxygen channel. Each coolant inlet may be positioned adjacent to one of the anode inlet and the cathode inlet, so that the reactant passing through the anode inlet or the cathode inlet is thermally connected to the coolant entering one of the coolant inlets. The fuel cell plate assembly may include three pressure regulators, each located at one of the coolant inlet and the coolant outlet. The pressure regulator may be adjusted to promote a substantially constant coolant flow between the coolant inlet and the coolant outlet. The first coolant channel configuration and the second coolant channel configuration may define a serpentine shape between the corresponding coolant inlet and the coolant outlet, respectively. The fuel cell plate assembly may include a pressure regulator, a sensor, and a controller located at each of the coolant inlet and the coolant outlet. Each sensor may be positioned at each of the anode inlet and the cathode inlet to monitor the thermal condition of the reactant entering. The controller may communicate with the pressure regulator and the sensor and be configured to adjust the coolant pressure based on the thermal condition of the monitored anode inlet or cathode inlet. The controller may instruct the pressure regulator to operate to maintain a constant coolant flow throughout the first coolant channel configuration and the second coolant channel configuration. The arrangement of the inlet may affect the reactant temperature at the anode inlet and the cathode inlet so that the reactant temperature is between sixty degrees Celsius and seventy degrees Celsius.

[0005] A fuel cell assembly includes a plate assembly and three pressure regulators. The plate assembly includes a first coolant inlet positioned between an anode inlet and a cathode outlet, a second coolant inlet positioned between a cathode inlet and an anode outlet, and a third coolant inlet positioned on a first side of the plate assembly, the third coolant inlet being opposite to a coolant outlet positioned on a second side of the plate assembly. The three pressure regulators control the coolant flow pressure through one of the first coolant inlet, the second coolant inlet, and the third coolant inlet, respectively. The pressure regulators are arranged together to adjust the coolant flow pressure so that the coolant flow pressure at the coolant outlet is less than the coolant flow pressure at the third coolant inlet, wherein the coolant flow pressure at the third coolant inlet is less than the coolant flow pressure at the first coolant inlet and the second coolant inlet. The three pressure regulators can be adjusted to promote a substantially constant coolant flow at the central region of the plate assembly. The three pressure regulators can be adjusted to promote a flow pressure of approximately 3.0 atmospheres at the first coolant inlet and the second coolant inlet, and promote a flow pressure of approximately 1.3 atmospheres at the third coolant inlet. The fuel cell assembly may include a fourth pressure regulator for maintaining the coolant flow pressure through the coolant outlet at a pressure lower than the pressure of the coolant inlet. The fuel cell assembly may include a sensor and a controller. The sensor may be positioned at each coolant inlet and coolant outlet for measuring the pressure of the coolant flow. The controller may communicate with the sensor and the three pressure regulators and be configured to adjust the pressure control of the three pressure regulators so that the flow pressure of the coolant at the coolant outlet is between 1.2 atmospheres and 3.1 atmospheres. The fuel cell assembly may include a hydrogen channel, an oxygen channel, and a coolant channel. The hydrogen channel may extend between the anode inlet and the anode outlet. The oxygen channel may extend between the cathode inlet and the cathode outlet. The coolant channel may extend between the coolant inlet and the coolant outlet. The channels may be arranged together so that the hydrogen channel and the oxygen channel are disposed between the coolant channels for thermal communication between the reactants and the coolant flowing through the corresponding channels. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a schematic diagram depicting an example of a fuel cell vehicle.

[0007] Figure 2 is a schematic diagram depicting an example of a fuel cell.

[0008] Figure 3 is a schematic diagram depicting a perspective view of an example of a portion of a fuel cell assembly.

[0009] Figure 4 is a schematic diagram depicting a plan view of an example of a portion of a fuel cell assembly.

[0010] Figure 5is a schematic diagram depicting a plan view of an example of a portion of a fuel cell assembly.

[0011] Figure 6 yes Figure 4 A cross-sectional view of a portion of a plate assembly of a fuel cell assembly.

[0012] Figure 7 is a schematic diagram depicting a plan view of an example of a portion of a fuel cell assembly.

[0013] Figure 8 yes Figure 7 Detailed view of a portion of a plate assembly of a fuel cell assembly.

[0014] Fig. 9 is a schematic diagram depicting a plan view of an example of a portion of a fuel cell assembly. DETAILED DESCRIPTION

[0015] Embodiments of the present disclosure are described herein. However, it should be understood that the disclosed embodiments are only examples, and other embodiments may take various alternative forms. The drawings need not be drawn to scale; some features may be exaggerated or minimized to show the details of specific components. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but only as a representative basis for teaching those skilled in the art to utilize the embodiments of the present disclosure in various forms. As will be understood by those of ordinary skill in the art, the various features shown and described with reference to any of the figures may be combined with the features shown in one or more other figures to produce embodiments that are not explicitly shown or described. The combination of features shown provides representative embodiments for typical applications. However, various combinations and variations of features consistent with the teachings of the present disclosure may be desired for specific applications or implementations.

[0016] Figure 1 A schematic diagram of an example of a fuel cell vehicle (generally referred to herein as vehicle 10) is depicted. The vehicle 10 may include one or more motors 12 mechanically connected to a transmission 14. Each motor 12 can operate as a motor or a generator. The transmission 14 may also be mechanically connected to a drive shaft 20, which is mechanically connected to a set of front wheels 22 or rear wheels. The motor 12 may provide propulsion and deceleration capabilities. A fuel cell stack system 24 may generate current to power components of the vehicle 10. For example, a hydrogen and oxygen delivery system may operate with the fuel cell stack system 24 to convert hydrogen and oxygen into current to power the motor 12. Current may be referred to as a load. The fuel cell stack system 24 may include one or more fuel cells constituting a fuel cell stack, such as a polymer electrolyte membrane (PEM) fuel cell.

[0017] The fuel cell stack system 24 may also include a thermal management system and / or an air flow control system. The thermal management system and / or the air flow control system may include, for example, a compressor. The power control unit 26 may manage the current within the vehicle 10. For example, the power control unit 26 may manage the current between the fuel cell stack system 24 and the motor 12. The hydrogen storage tank 30 may store hydrogen for use by the fuel cell stack system 24. The high output battery 32 may store, for example, energy generated from a regenerative braking system and may provide supplemental power to the motor 12.

[0018] Each of the components described above may have one or more associated controllers to control and monitor the operation of the components.The controllers may communicate via a serial bus, such as a controller area network (CAN), or via discrete conductors.

[0019] Figure 2 A schematic diagram of an example of a proton exchange membrane (PEM) fuel cell (generally referred to herein as a PEM fuel cell 40) is depicted. The PEM fuel cell 40 is an example of a fuel cell that can be operated in the fuel cell stack system 24 described above. The PEM fuel cell 40 may include an anode 42, an electrolyte 44, and a cathode 46. Chemical reactions may occur at the interface between the anode 42, the electrolyte 44, and the cathode 46. For example, the anode 42 may receive a fuel (such as hydrogen) and oxidize the fuel to convert the fuel into one or more positively charged ions and one or more negatively charged electrons. The electrolyte 44 may allow ions to pass through to the cathode 46 while redirecting electrons around the electrolyte 44 to establish a load. The electrons may recombine the ions within the cathode 46. The cathode 46 may receive a chemical such as oxygen to react with the ions and electrons to produce (for example) water or carbon dioxide. The bipolar plate 48 may assist in distributing the fuel and oxidant within the PEM fuel cell 40, facilitate water management of the PEM fuel cell 40, separate the fuel cells within the fuel cell stack, and facilitate thermal management of the PEM fuel cell 40.

[0020] Air and water management associated with a system including a fuel cell, such as a PEM fuel cell 40, can affect the performance of the system. For example, the electrodes of the fuel cell may be flooded with liquid water having excess hydration greater than normal, which may result in fuel starvation, cell potential or current reversal, or corrosion of the electrodes and bipolar plates. Conversely, too little hydration may make the resistance to proton transport in a membrane (e.g., an electrolyte of a fuel cell) higher and may promote free radical scavenging by the membrane. Swings in the hydration state of the system may cause mechanical stresses in the membrane, which may also result in premature failure of the membrane. Control strategies may change the cycle conditions during system operation by adjusting temperature, flow, pressure, and current consumption to improve performance and extend the life of the system.

[0021] Figure 3 A schematic diagram of an example of a fuel cell assembly (generally referred to herein as a fuel cell assembly 50) is shown. The fuel cell assembly 50 may include one or more plate assemblies 52. The plate assemblies 52 each include an anode, an electrolyte, and a cathode to operate as a fuel cell. Alternatively, the plate assembly 52 may generally include an anode, an electrolyte, and a cathode to operate as a fuel cell.

[0022] Each of the one or more plate assemblies 52 includes an anode inlet and an anode outlet, a cathode inlet and a cathode outlet, and channels in fluid communication with each inlet and outlet for reactants to flow therethrough. Each of the one or more plate assemblies 52 includes a flow field for a coolant and one or more coolant inlets and coolant outlets. The flow field may include one or more channels. Each plate assembly 52 may be arranged for thermal communication between a coolant flowing within the flow field and reactants of the fuel cell assembly 50. Figure 3 As shown, one or more panel assemblies 52 may be mounted in a stack.

[0023] Figure 4 A schematic diagram of a plan view of a previously known example of a portion of a fuel cell assembly (referred to herein as a fuel cell assembly 100) is shown. The components of the fuel cell assembly 100 operate as a fuel cell with each other. The fuel cell assembly 100 includes a plate assembly 104. The plate assembly 104 includes an anode inlet 106, an anode outlet 108, a cathode inlet 110, a cathode outlet 112, a coolant inlet 118, and a coolant outlet 120. The plate assembly 104 can provide flow paths for anode reactants, cathode reactants, and coolants. An illustrative hydrogen flow path 124 extends from the anode inlet 106 to the anode outlet 108. An illustrative oxygen flow path 126 extends from the cathode inlet 110 to the cathode outlet 112. An illustrative coolant flow path 128 extends from the coolant inlet 118 to the coolant outlet 120. The hydrogen flow path 124 and the oxygen flow path 126 are shown as intersecting adjacent to each other at a central region of the plate assembly 104.

[0024] The hot zone 142 represents a portion of the fuel cell assembly 100 where the reactant flow path and the coolant flow path are at their hottest. In this example, the hot zone 142 is located adjacent to the cathode outlet 112, the anode inlet 106, and the coolant outlet 120. The hot zone 142 can affect the gas passing through the anode inlet 106 to have dry characteristics below acceptable conditions. These dry characteristics may damage the membrane of the fuel cell assembly 100. The alternative configuration of the coolant inlet 118, the coolant outlet 120, and the components of the fuel cell assembly 100 can assist in providing a more favorable thermal condition for the area near the anode inlet 106 and the cathode inlet 110.

[0025] Figure 5and Figure 6 An example of a portion of a fuel cell assembly, referred to herein as fuel cell assembly 150 , is shown. Figure 5 A schematic diagram of a plan view of a fuel cell assembly 150 is shown. The fuel cell assembly 150 may include a fuel cell, a plate assembly 154, an anode inlet 156, an anode outlet 158, a cathode inlet 160, and a cathode outlet 162. The fuel cell includes an anode, an electrolyte, and a cathode. The fuel cell may be a separate unit or may be composed of components of the plate assembly 154. The plate assembly 154 may include more than one layer and various inlet and outlet configurations to deliver and remove coolant and deliver and remove reactants from the coolant flow field. One or more first channels (e.g., Figure 6 The hydrogen channel 197 shown in FIG. 1 may direct the reactants through one or more manifolds and fluidly connect the anode inlet 156 to the anode outlet. One or more second channels (e.g., Figure 6 The oxygen channels 196 shown in Figure 1 may direct the reactants through one or more additional manifolds to fluidly connect the cathode inlet 160 and the cathode outlet 162. The one or more first channels and the one or more second channels may be adjacent to the coolant channels of the plate assembly 154 (e.g., Figure 6 The anode inlet and anode outlet, the cathode inlet and cathode outlet, and the coolant channel inlet and coolant channel outlet can be arranged together to promote the thermal condition of the reactants flowing through the channel while also providing a counterflow of the reactants for chemical reaction purposes. For example, the inlets can be arranged together so that the coolant affects the reactant temperature at the anode inlet 156 and the cathode inlet 160 to maintain a uniform hydration distribution on the fuel cell membrane.

[0026] The plate assembly 154 may include a first coolant inlet 166, a second coolant inlet 168, a first coolant outlet 170, and a second coolant outlet 172. The first coolant inlet 166 and the second coolant inlet 168 may be located on opposite sides of the plate assembly 154. Figure 5As shown, each of the first coolant inlet 166 and the second coolant inlet 168 may be arranged between the inlet and outlet of the anode and the cathode and / or positioned adjacent to the inlet and outlet of the anode and the cathode. For example, the first coolant inlet 166 is shown as being positioned adjacent to the anode inlet 156 and the cathode outlet 162 and positioned between the anode inlet 156 and the cathode outlet 162. The second coolant inlet 168 is shown as being positioned adjacent to the cathode inlet 160 and the anode outlet 158 ​​and positioned between the cathode inlet 160 and the anode outlet 158. Positioning the anode inlet 156 and the cathode inlet 160 adjacent to the coolant inlet provides a thermal management benefit for the reactants passing through the reactant inlet. Compared with the previous fuel cell assembly example, the coolant operation is used to cool the reactants at each inlet to eliminate hot zones (such as, hot zone 142), and eliminate or minimize the dry characteristics found in the previous inlet and outlet configurations, while improving the hydration conditions of the fuel cell.

[0027] The flow of coolant within the plate assembly 154 also affects the thermal conditions of the fuel cell assembly 150. The coolant flows from the coolant inlet to the coolant outlet via a pair of manifold regions 180, a pair of first flow field regions 182, and a central flow field region 184, as represented by flow path arrows 190. The central flow field region 184 may be an area of ​​the plate assembly 154 where coolant flow is obstructed when coolant from opposing inlets meets each other. A variety of structures may be used to help minimize such obstruction.

[0028] For example, features such as columns 194 may be positioned within the central flow field region 184 to induce turbulence within the coolant flow and promote a more constant coolant flow from the coolant inlet to the coolant outlet. Although columns 194 are shown as being generally square in this example, it is contemplated that other shapes are available. The channels of the plate assembly 154 may be arranged together to promote thermal communication between the coolant and the reactants.

[0029] A pressure regulator may be installed at each of the coolant inlet and the coolant outlet to adjust the pressure of the coolant flow. For example, a first pressure regulator 187 may be installed at the first coolant inlet 166 for controlling the coolant flow pressure. A second pressure regulator 189 may be installed at the second coolant inlet 168 for controlling the coolant flow pressure. A third pressure regulator 191 may be installed at the first coolant outlet 170 for controlling the coolant flow pressure. A fourth pressure regulator 201 may be installed at the second coolant outlet 172. The pressure regulator may be adjusted to promote a constant coolant flow from the coolant inlet to the coolant outlet.

[0030] The controller may communicate with the sensor and the pressure regulator to control the coolant flow pressure. For example, one or more sensors may monitor the thermal and pressure conditions at each inlet and outlet. The controller may be configured to output a pressure command to each pressure regulator to adjust the coolant flow pressure based on the monitored thermal and pressure conditions. In one example, the controller may instruct the pressure regulator to increase the coolant flow pressure in response to a signal received from the sensor indicating that the temperature of the reactant at one of the anode inlet 156 or cathode inlet 160 is higher than a predetermined threshold. The predetermined threshold may be a temperature threshold representing the optimal reactant condition for fuel cell operation. In one example, the optimal temperature range may be between sixty degrees Celsius and seventy degrees Celsius. The optimal hydration condition of the membrane may be a lambda value between seven and ten moles of water per mole of acid.

[0031] Figure 6 1 is a cross-sectional view of a portion of a plate assembly 154, showing further details of a multi-plate embodiment of the plate assembly 154. In this example, the plate assembly 154 has two plates 193. Each plate 193 can be made of carbon or metal materials, such as graphite, stainless steel or titanium coated with a coating. Channels for reactants and coolants are positioned adjacent to each other in each plate 193 for thermal communication therebetween. For example, a coolant channel 195 is shown as being positioned adjacent to an oxygen channel 196 and a hydrogen channel 197. The coolant flowing through the coolant channel 195 absorbs heat from the oxygen and hydrogen flowing through the oxygen channel 196 and the hydrogen channel 197, respectively. Walls 198 can separate the individual channels from each other. When the plates 193 are stacked, the oxygen channel 196 and the hydrogen channel 197 can be arranged on opposite sides of the membrane 199 to facilitate operation as a fuel cell.

[0032] Figure 7 and Figure 8 Another example of a portion of a fuel cell assembly (referred to herein as fuel cell assembly 200 ) is shown. Figure 7A schematic plan view of a portion of a fuel cell assembly 200 is shown. The fuel cell assembly 200 may include a fuel cell and a plate assembly 206. The plate assembly 206 may include an anode inlet 208, an anode outlet 210, a cathode inlet 212, and a cathode outlet 214. The plate assembly 206 includes an anode, an electrolyte, and a cathode. Similar to the plate assembly 154, the plate assembly 206 may include two plates with a coolant channel and a reactant channel. The plate assembly 206 may include more than one layer and various inlet and outlet configurations to transport and remove coolant from a coolant flow field. A set of first channels 211 fluidly connects the anode inlet 208 to the anode outlet 210 for allowing a reactant to flow therethrough, and a set of second channels 213 connects the cathode inlet 212 to the cathode outlet 214 for allowing another reactant to flow therethrough. The anode inlet and anode outlet, the cathode inlet and cathode outlet, and the coolant channel inlet and coolant channel outlet may be arranged together to promote the thermal conditions of the reactants while also providing a counterflow of reactants for chemical reaction purposes.

[0033] For example, the plate assembly 206 may include a first coolant inlet 218, a second coolant inlet 220, a third coolant inlet 224, and a coolant outlet 226. The first coolant inlet 218 and the third coolant inlet 224 may be positioned on opposite sides of the plate assembly 206. Figure 7 As shown, each of the first coolant inlet 218 and the third coolant inlet 224 can be arranged between the inlet and outlet of the anode and the cathode and / or adjacent to the inlet and outlet of the anode and the cathode. For example, the first coolant inlet 218 is shown as being positioned adjacent to the anode inlet 208 and the cathode outlet 214 and positioned between the anode inlet 208 and the cathode outlet 214. The third coolant inlet 224 is shown as being positioned adjacent to the cathode inlet 212 and the anode outlet 210 and positioned between the cathode inlet 212 and the anode outlet 210. Positioning the anode inlet 208 and the cathode inlet 212 adjacent to the coolant inlet provides thermal management benefits for the reactants passing through each inlet. The coolant (coolest at the coolant inlet) operates to cool the reactants at the inlet to eliminate hot zones (such as, hot zone 142), and eliminates or minimizes the drying characteristics found in the previous inlet and outlet configurations, while improving hydration conditions. The second coolant inlet 220 and the coolant outlet 226 are positioned on opposite sides of the plate assembly 206.

[0034] As described above, the flow of coolant within the plate assembly 206 also affects the thermal condition of the fuel cell assembly 200. The coolant flows from the coolant inlet to the coolant outlet 226 via a pair of manifold regions 230, a pair of first flow field regions 232, and a central flow field region 234, as indicated by flow path arrows 238. The channels of the plate assembly 206 can be arranged together to promote thermal communication between the coolant and the reactants, further assisting thermal communication through uniform coolant flow. The central flow field region 234 can be an area in the plate assembly 206 where the coolant flow is obstructed when the coolant from the inlet meets each other. A variety of structures can be used to help minimize such obstruction.

[0035] For example, features such as posts 240 may be positioned within the central flow field region 234 to induce turbulence within the coolant flow and promote a more constant coolant flow from the coolant inlet to the coolant outlet. Although posts 240 are shown as being generally square in this example, it is contemplated that other shapes may be useful.

[0036] Various pressurization applications may also assist in managing the coolant flow within the plate assembly 206. For example, a pressure regulator 242 may be positioned at each of the coolant channel inlet and the coolant outlet 226 to assist in managing the coolant flow at a desired and predetermined flow rate. The coolant flow rate may be adjusted to be substantially equal to the flow rate of hydrogen and oxygen, such as a flow rate between one atmosphere and 3.5 atmospheres. In one example, the coolant flow at the first coolant inlet 218 and the third coolant inlet 224 may be adjusted to have a high pressure, such as a flow rate of 3 atmospheres. The coolant flow at the second coolant inlet 220 may be adjusted to have a medium pressure less than the high pressure, such as 1.3 atmospheres. The coolant flow at the coolant outlet 226 may be adjusted to have a low pressure less than the medium pressure, such as 1.2 atmospheres.

[0037] The controller may be in communication with the sensor and the pressure regulator 242 to control the coolant flow pressure. For example, one or more sensors may monitor the thermal and pressure conditions at each inlet and outlet. The controller may be configured to output a pressure command to each pressure regulator 242 to adjust the coolant flow pressure based on the monitored thermal and pressure conditions. In one example, the controller may instruct the pressure regulator 242 to increase the coolant flow pressure in response to a signal indicating that the temperature of the reactant at one of the anode inlet 208 or cathode inlet 212 received from the sensor is higher than a predetermined threshold. The predetermined threshold may be a temperature threshold associated with an optimal reactant condition.

[0038] Optionally, the structure of the coolant channels may assist in managing the pressurization of the coolant flow within the plate assembly 206 . Figure 8An example of a series of coolant channels with bottleneck portions of different widths is shown to selectively affect the coolant flow in the flow field by restricting the coolant flow at the bottleneck portion. The first coolant channel 249 defines a portion having a first width 250, the second coolant channel 251 defines a portion having a second width 252, and the third coolant channel 253 defines a portion having a third width 254. The second width 252 defines a width greater than the first width 250 and less than the third width 254. The coolant channels can be arranged together with each other so that the width increases from the outside of each of a pair of first flow field regions 232 to the inside of each of a pair of first flow field regions 232 in the subsequent coolant channels. The arrangement of the bottleneck portion can produce a constant flow to the coolant outlet 226 by affecting the flow rate of the coolant that meets at the central flow field region 234.

[0039] Fig. 9 Yet another example of a portion of a fuel cell assembly (referred to as fuel cell assembly 300) is shown. Fuel cell assembly 300 may include a fuel cell and a plate assembly 306. Plate assembly 306 may include an anode inlet 308, an anode outlet 310, a cathode inlet 312, and a cathode outlet 314. Fuel cell assembly 300 includes an anode, an electrolyte, and a cathode. Plate assembly 306 may include more than one layer and various inlet and outlet configurations to deliver and remove coolant from a coolant flow field. Anode channel 315 connects anode inlet 308 to anode outlet 310 for flowing hydrogen therethrough, and cathode channel 317 connects cathode inlet 312 and cathode outlet 314 for flowing oxygen therethrough. Anode channel 315 may deliver hydrogen to a first manifold 319. First manifold 319 may assist in delivering hydrogen to a hydrogen channel ( Fig. 9 ), and then delivered to the second manifold 321 leading to the anode outlet 310.

[0040] Anode inlet 308, anode outlet 310, cathode inlet 312, cathode outlet 314, coolant channel inlet, and coolant channel outlet may be arranged with one another to promote thermal conditions for the hydrogen and oxygen reactants while also providing counter-flow of the reactants for chemical reaction purposes.

[0041] The plate assembly 306 may include more than one plate and various inlet and outlet configurations to deliver and remove coolant from the coolant flow field. For example, the plate assembly 306 may include one or more coolant channel configurations, such as a first coolant channel configuration 320 and a second coolant channel configuration 324. Each coolant channel configuration may be arranged on the plate assembly 306 so that the coolant flows in a direction substantially perpendicular to the directional flow of the reactants.

[0042] For example, the first coolant channel configuration 320 may include a first coolant inlet 330 and a first coolant outlet 332. A coolant channel 334 extends between the first coolant inlet 330 and the first coolant outlet 332 in a serpentine manner for coolant flow (indicated by flow arrows 338). The second coolant channel configuration 324 may include a second coolant inlet 340 and a second coolant outlet 342. The coolant channel 344 extends between the second coolant inlet 340 and the second coolant outlet 342 in a serpentine manner for coolant flow (indicated by flow arrows 348). In one example, the first coolant outlet 332 and the second coolant outlet 342 may be a single outlet to simplify the coolant piping of the plate assembly 306. It is contemplated that one of the hydrogen channel and the oxygen channel may be provided in the first coolant channel configuration and the second coolant channel configuration 324 (similar to Figure 6 Extending above the coolant channels and reactant channels as shown in the orientation of the coolant channels and reactant channels.

[0043] Various pressurization applications may also assist in managing coolant flow within the plate assembly 306. For example, a pressure regulator 350 may be positioned at each of the coolant channel inlet and the coolant channel outlet to assist in managing coolant flow at a predetermined coolant flow rate. In one example, the coolant flow at the first coolant inlet 330 and the second coolant inlet 340 may be regulated to have a first pressure. The coolant flow at the first coolant outlet 332 and the second coolant outlet 342 may be regulated to have a second pressure that is lower than the first pressure. The first pressure and the second pressure may be predetermined based on a desired coolant flow rate through the coolant channel.

[0044] The controller can communicate with the sensor and pressure regulator 350 to control the coolant flow pressure. For example, one or more sensors 352 can monitor the thermal and pressure conditions at each inlet and outlet. The controller can be configured to output a pressure command to each pressure regulator 350 to adjust the coolant flow pressure based on the monitored thermal and pressure conditions. In one example, the controller can instruct the pressure regulator 350 to increase the coolant flow pressure in response to a signal received from one or more sensors 352 indicating that the temperature of the reactant at one of the anode inlet 308 or cathode inlet 312 is higher than a predetermined threshold.

[0045] Although exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms covered by the claims. The words used in the specification are descriptive rather than restrictive, and it should be understood that various changes can be made without departing from the spirit and scope of the present disclosure. As previously mentioned, the features of each embodiment can be combined to form further embodiments of the present disclosure that may not be clearly described or shown. Although each embodiment has been described as providing advantages or being superior to other embodiments or prior art implementations in one or more desired characteristics, it will be appreciated by those of ordinary skill in the art that, according to specific applications and implementations, one or more features or characteristics can be compromised to achieve desired overall system properties. These properties may include, but are not limited to, marketability, appearance, consistency, robustness, customer acceptability, reliability, accuracy, etc. Therefore, embodiments described as being less desirable than other embodiments or prior art implementations in one or more characteristics are not outside the scope of the present disclosure, and can be expected to be used for specific applications.

Claims

1. A fuel cell assembly, comprising: one or more plate assemblies, each plate assembly including an anode inlet disposed on a first plate side, a cathode inlet disposed on a second plate side, a first coolant inlet positioned adjacent to the anode inlet, a second coolant inlet positioned adjacent to the cathode inlet, and a coolant channel connected to the first coolant inlet and the second coolant inlet, Wherein the first coolant inlet and the second coolant inlet are arranged such that the coolant affects the reactant temperature at the anode inlet and the cathode inlet to promote formation of a uniform hydration distribution of the membrane during fuel cell operation.

2. The fuel cell assembly according to claim 1, further comprising: a hydrogen channel extending between an anode inlet and an anode outlet disposed on a side of the second plate; an oxygen channel extending between a cathode inlet and a cathode outlet disposed on a side of the first plate; wherein the coolant channel extends between a first coolant inlet and a coolant outlet, The coolant channel extends between the hydrogen channel and the oxygen channel to absorb heat from hydrogen and oxygen flowing through the hydrogen channel and the oxygen channel and to bring hydrogen and oxygen close enough to each other for a chemical reaction between the hydrogen and oxygen.

3. The fuel cell assembly according to claim 1, each plate assembly further comprising a first coolant outlet disposed on the third plate side, a second coolant outlet disposed on the fourth plate side, and a coolant flow field fluidly connecting the coolant inlet and the coolant outlet, wherein The coolant inlet and the coolant outlet are arranged together with each other so that the flow rate of the coolant from the coolant inlet to the coolant outlet is evenly distributed in the coolant flow field.

4. The fuel cell assembly according to claim 1, each plate assembly further comprising a first coolant outlet disposed on the third plate side, a second coolant outlet disposed on the fourth plate side, and a coolant flow field fluidly connecting the coolant inlet and the coolant outlet, wherein The coolant flow field includes a central region having one or more posts to affect turbulence in the coolant flow to promote uniform coolant flow from the coolant inlet to the coolant outlet.

5. The fuel cell assembly according to claim 1, wherein: Each plate assembly also includes two plates, each plate including a pair of serpentine walls, a hydrogen channel and an oxygen channel, the pair of serpentine walls being arranged together to form two separate coolant channels between the serpentine walls, the hydrogen channel extending substantially perpendicular to a portion of one of the coolant channels and extending between an anode inlet and an anode outlet, the oxygen channel extending substantially perpendicular to a portion of one of the coolant channels and extending between a cathode inlet and a cathode outlet, wherein the channels are arranged together to allow the hydrogen channel and the oxygen channel to be adjacent to each other to promote a chemical reaction between the hydrogen channel and the oxygen channel, and to allow the coolant flowing through the coolant channel to be thermally connected to the hydrogen and oxygen flowing through the hydrogen channel and the oxygen channel.

6. The fuel cell assembly according to claim 1, further comprising: a first pressure regulator for controlling a first coolant flow pressure at a first coolant inlet; a second pressure regulator for controlling the flow pressure of the second coolant at the second coolant inlet; a third pressure regulator for controlling the flow pressure of the third coolant at the first coolant outlet, Wherein the first pressure regulator, the second pressure regulator, and the third pressure regulator are adjusted to promote a constant coolant flow from a coolant inlet to a coolant outlet.

7. The fuel cell assembly according to claim 1, wherein: The arrangement of the inlets influences the reactant temperature at the anode and cathode inlets so that the temperature is between sixty and seventy degrees Celsius.

8. A fuel cell plate assembly comprising: a hydrogen channel extending from an anode inlet to an anode outlet; an oxygen channel extending from a cathode inlet to a cathode outlet; The first coolant channel configuration and the second coolant channel configuration each include a coolant inlet and a coolant outlet, wherein the anode inlet and the cathode outlet are positioned on a first plate side, the cathode inlet and the anode outlet are positioned on a second plate side opposite to the first plate side, each coolant inlet is positioned on a third plate side, and each coolant outlet is positioned on a fourth plate side opposite to the third plate side, such that the coolant within the first coolant channel configuration and the second coolant channel configuration flows in a direction substantially perpendicular to a portion of the hydrogen flowing within the hydrogen channel and a portion of the oxygen flowing within the oxygen channel.

9. The fuel cell plate assembly according to claim 8, wherein: Each coolant inlet is positioned adjacent one of the anode inlet and the cathode inlet such that reactants passing through the anode inlet or the cathode inlet are in thermal communication with coolant entering one of the coolant inlets.

10. The fuel cell plate assembly according to claim 8, further comprising three pressure regulators, each located at one of the coolant inlet and the coolant outlet, wherein: The three pressure regulators are regulated to promote a substantially constant coolant flow between the coolant inlet and the coolant outlet.

11. The fuel cell plate assembly according to claim 8, wherein: The first coolant channel configuration and the second coolant channel configuration define a serpentine shape between the corresponding coolant inlet and coolant outlet, respectively.

12. The fuel cell plate assembly according to claim 8, further comprising: a pressure regulator located at each of the coolant inlet and the coolant outlet; a sensor located at each of the anode inlet and the cathode inlet to monitor the thermal condition of the incoming reactants; A controller is in communication with the pressure regulator and the sensor and is configured to regulate coolant pressure based on monitored thermal conditions of the anode inlet or the cathode inlet.

13. The fuel cell plate assembly according to claim 12, wherein: The controller directs the pressure regulator to operate to maintain a constant coolant flow throughout the first coolant channel configuration and the second coolant channel configuration.

14. The fuel cell plate assembly according to claim 8, wherein: The arrangement of the inlets influences the reactant temperature at the anode and cathode inlets so that the reactant temperature is between sixty and seventy degrees Celsius.

15. A fuel cell assembly comprising: one or more plate assemblies, each plate assembly including a first coolant inlet positioned between an anode inlet and a cathode outlet, a second coolant inlet positioned between the cathode inlet and the anode outlet, and a third coolant inlet positioned on a first side of the plate assembly, the third coolant inlet being opposite the coolant outlet positioned on the second side of the plate assembly, the first coolant inlet and the anode inlet and the cathode outlet being positioned on a third side of the plate assembly, and the second coolant inlet and the cathode inlet and the anode outlet being positioned on a fourth side of the plate assembly opposite the third side; three pressure regulators, respectively for controlling the coolant flow pressure through one of the first coolant inlet, the second coolant inlet and the third coolant inlet, The three pressure regulators are arranged together to adjust the coolant flow pressure so that the coolant flow pressure at the coolant outlet is less than the coolant flow pressure at the third coolant inlet, wherein the coolant flow pressure at the third coolant inlet is less than the coolant flow pressure at the first coolant inlet and the second coolant inlet.

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