Fuel cell gas humidifier

Abstract

The invention discloses a fuel cell gas humidifier, which relates to the field of proton exchange membrane fuel cells, and comprises a tank body, a gas inlet, a gas distributor and a gas outlet, the interior of the tank body is sequentially divided into a liquid area, a filler area and an air outlet area from bottom to top, the liquid area is used for storing a humidifying solution, and a filler layer of a porous structure is arranged in the filler area; a gas inlet communicated with the liquid area and a gas outlet communicated with the gas outlet area are formed in the outer side of the tank body, and a gas distributor with a porous structure is arranged in the gas inlet. The device has the advantages that the humidifying humidity of the reaction gas is improved, and the situation that when the PEMFC is quickly started and activated or the load pulling load suddenly and greatly changes, the gas flow is instantaneously increased, and consequently liquid in the tank body violently shakes can be prevented.

Description

Technical Field

[0001] The present invention relates to the field of proton exchange membrane fuel cells, and particularly to a fuel cell gas humidifier. Background Art

[0002] Due to its advantages such as high energy conversion efficiency, fast response and startup, low noise, strong adaptability, clean and environmentally friendly, and simple structure, the proton exchange membrane is used in fields such as transportation, aerospace, and fuel cells. Inside a proton exchange membrane fuel cell (PEMFC), the proton exchange membrane provides a channel for the migration and transportation of protons, enabling protons to pass through the membrane from the anode to the cathode, forming a loop with the electron transfer in the external circuit and providing current to the outside world. Among them, the humidification degree of the membrane electrode more directly reflects the performance of the PEMFC. This is mainly because the proton membrane can only conduct protons at a certain humidity. If the humidity is too low, the conductivity of the membrane will be too low, resulting in an increase in the internal resistance of the battery and a decrease in battery performance; conversely, if the humidity is too high, it will cause flooding of the electrodes, resulting in an increase in the resistance of gas entering the electrodes, an increase in mass transfer resistance, and poor battery performance. Therefore, a proton exchange membrane with an appropriate humidity plays an important role in the performance of the PEMFC.

[0003] In practical applications, the methods of membrane humidification during PEMFC testing can be divided into two categories: one is self-humidification, and the other is internal humidification and external humidification. Among them, the self-humidification technology does not need to obtain moisture from the outside. By using the water generated by the electrochemical reaction and the internal structure of the PEMFC, the internal moisture of the PEMFC reaches an equilibrium state. This technology is difficult and costly, so generally, internal humidification and external humidification technologies are mostly used. In the internal humidification and external humidification technologies, the humidification device for internal humidification is located inside the PEMFC. An additional humidification chamber is added inside the PEMFC, and the humidification process is completed by using the concentration gradient and pressure gradient existing on both sides of the membrane, such as a membrane humidifier. The moisture in the humidification device can directly flow into the PEMFC; for external humidification, a humidifier outside the PEMFC needs to be used to humidify the reaction gas. For example, a bubbler humidifier, whose principle is to pass the reaction gas through the humidifier from the lower end of the tank container and discharge it from the upper end, and humidify it by bubbling.

[0004] The core of the membrane humidifier is a perfluorosulfonic acid proton exchange membrane (PFSA). A gas or liquid with high humidity is introduced into the wet side of the membrane, and a dry gas to be humidified is introduced into the dry side on the other side of the membrane. Since water can diffuse in the PFSA, water will diffuse from the wet side with a high concentration to the dry side with a low concentration, realizing the humidification of the dry gas. The humidification efficiency of the membrane humidifier comes from the transmembrane transport of water. The greater the amount of water transferred from the wet side to the dry side per unit time, the more significant the humidification effect.

[0005] Bubble humidifier is a commonly used humidification method for PEMFC external humidification, which mainly controls the bubbler through water temperature. It usually contains porous materials to disperse bubbles, expand the evaporation surface area of ​​water, and facilitate the wetting of the reaction gas. For example, the patent document with publication number CN114447363A discloses a gas humidification temperature control system for a fuel cell stack test system, including a humidification tank containing liquid, a gas distributor leading to the interior of the humidification tank is arranged at the lower part of the humidification tank, and an outlet pipe is arranged at the outlet of the top of the humidification tank, a heating tape is wrapped around the outlet pipe, and an outlet pipe heater is arranged on the outlet pipe.

[0006] The gas-liquid interaction area of ​​the internal structure of the existing bubbling humidifier is insufficient. When the battery starts quickly and the activation load suddenly changes drastically, the gas flow increases instantaneously, and the bubbling humidifier cannot respond synchronously with the working conditions in time, resulting in insufficient humidification humidity; and the existing bubbling humidifier has an external heating device to control the temperature of the humidifying solution, which makes it difficult to quickly reach the required dew point temperature and pressure, and it is easy to cause large fluctuations in the dew point temperature under large atmospheric conditions. Summary of the invention

[0007] The technical problem to be solved by the present invention is how to increase the humidification humidity of the reaction gas.

[0008] The present invention solves the above-mentioned technical problems through the following technical means: a fuel cell gas humidifier, comprising a tank body, an air inlet, a gas distributor and an air outlet; the interior of the tank body is divided into a liquid area, a filler area and an air outlet area from bottom to top, the liquid area is used to store a humidifying solution, and a filler layer with a porous structure is provided inside the filler area; the outside of the tank body is provided with an air inlet connected to the liquid area and an air outlet connected to the air outlet area, and a gas distributor with a porous structure is provided inside the air inlet.

[0009] After the reaction gas enters the air inlet, it first passes through the gas distributor and then enters the humidifying solution in the liquid area. The gas distributor ensures that the gas can enter the solution evenly; the gas coming out from above the solution enters the packing layer, and the packing layer diffuses the gas into tiny bubbles, which increases the contact area between the gas and the liquid in a short time, fully humidifies the gas, and improves the humidification humidity of the reaction gas; and the packing layer can suppress the liquid brought up under the condition of large volume as much as possible, which can prevent the gas flow from increasing instantaneously when the PEMFC is quickly started and activated or the load suddenly changes drastically, causing the liquid inside the tank to slosh violently; this structural design ensures that the tank can achieve a higher humidification effect with a smaller volume. At the same time, the small volume of the tank is also conducive to reducing the back pressure time during the PEMFC test, ensuring the efficient operation of the PEMFC.

[0010] As an optimized technical solution, the fuel cell gas humidifier further includes a partition, and a plurality of staggered partitions are distributed in the gas outlet area.

[0011] The gas after passing through the packing layer coils through the gaps between the partition plates, further ensuring uniform humidification of the gas.

[0012] As an optimized technical solution, the fuel cell gas humidifier further includes a heating rod, a first temperature sensor, a second temperature sensor, and a PID controller. The heating rod enters the liquid area from the outside of the tank body, the first temperature sensor enters the liquid area from the outside of the tank body, the second temperature sensor enters the gas outlet area from the outside of the tank body, and the heating rod, the first temperature sensor, and the second temperature sensor are all connected to the PID controller.

[0013] The heating of the heating rod is controlled by the PID controller, and the humidification solution temperature and the gas outlet temperature are respectively detected by the first temperature sensor and the second temperature sensor. Then, the required solution temperature is controlled according to the measured temperature to form a closed loop for temperature control. The heating rod enters the solution and can quickly reach the required dew point temperature and pressure. The humidified reaction gas can be directly used by the PEMFC, solving the dynamic response problems generated during the rapid activation and load pulling of the PEMFC, and reducing the dew point temperature fluctuation under the condition of a large air volume.

[0014] As an optimized technical solution, the fuel cell gas humidifier further includes a pressure sensor. A pressure sensor communicating with the gas outlet area is provided on the outside of the tank body, and the pressure sensor is connected to the PID controller.

[0015] As an optimized technical solution, the fuel cell gas humidifier further includes a chuck, and the heating rod is fixedly connected to the tank body through the chuck.

[0016] As an optimized technical solution, the fuel cell gas humidifier further includes a water inlet, a drain outlet, a liquid level column, and a liquid level sensor. A water inlet and a drain outlet communicating with the liquid area are further provided on the outside of the tank body. The liquid level column is arranged on the outside of the tank body and communicates with the liquid area and the gas outlet area at both ends respectively. Liquid level sensors are respectively provided at positions corresponding to the high liquid level, the medium liquid level, and the low liquid level on the liquid level column.

[0017] The liquid level sensor can be used to control in real time whether the liquid area needs to be replenished or drained and the height of the liquid level. When the liquid level is lower than the low liquid level, automatic water replenishment will be triggered. When the liquid level reaches the medium liquid level, the water replenishment will stop. When the liquid level reaches the high liquid level, the emergency stop of the test bench will be triggered and automatic drainage will be carried out to avoid flooding the test bench and ensure the test safety.

[0018] As an optimized technical solution, the position of the low liquid level is higher than the lower end position of the heating rod. To prevent dry burning.

[0019] As an optimized technical solution, the liquid level column is made of a transparent material.

[0020] The liquid level column made of a transparent material facilitates real-time observation of the liquid level inside the tank.

[0021] As an optimized technical solution, the fuel cell gas humidifier further includes a dry gas port, and a dry gas port communicating with the gas outlet area is also provided on the outer side of the tank.

[0022] When purging the fuel cell stack, the reaction gas is not connected to the intake port but to the dry gas port, and flows directly out of the outlet without passing through the humidification process, achieving wet-dry separation and ensuring the diversity of experiments.

[0023] As an optimized technical solution, the fuel cell gas humidifier further includes a fixing plate, the fixing plate is fixedly connected to the outer surface of the tank, and the fixing plate is provided with connection holes.

[0024] The tank can be fixedly connected to the bench through bolts passing through the connection holes to ensure the stability of the tank.

[0025] The advantages of the present invention are as follows:

[0026] 1. After the reaction gas enters the intake port, it first passes through the gas distributor and then enters the humidification solution in the liquid area. The gas distributor ensures that the gas can enter the solution evenly; the gas coming out above the solution enters the packing layer, and the packing layer diffuses the gas into tiny bubbles, increasing the contact area between the gas and the liquid in a short time, fully humidifying the gas, and improving the humidification humidity of the reaction gas; and the packing layer can suppress the liquid carried under the condition of a large gas volume as much as possible, preventing the liquid inside the tank from violently sloshing when the gas flow rate instantaneously increases during the rapid start-up activation of the PEMFC or a sudden large change in the load pull; this structural design ensures that the tank can achieve a high humidification effect with a smaller volume, and at the same time, the smaller tank volume is also beneficial to reducing the backpressure time during the PEMFC test and ensuring the efficient operation of the PEMFC.

[0027] 2. The gas after passing through the packing layer coils through the gaps between the partitions, further ensuring uniform gas humidification.

[0028] 3. The heating rod is controlled by a PID controller to heat, and the temperature of the humidification solution and the outlet gas are respectively detected by the first temperature sensor and the second temperature sensor, and then the required solution temperature is controlled according to the measured temperature to form a closed loop of temperature control. The heating rod enters the solution and can quickly reach the required dew point temperature and pressure. The humidified reaction gas can be directly used by the PEMFC, solving the dynamic response problem generated during the rapid activation and load pull of the PEMFC and reducing the dew point temperature fluctuation under the condition of a large gas volume.

[0029] 4. The liquid level sensor can be used to control in real time whether water needs to be replenished or drained in the liquid area and the height of the liquid level. When the liquid level is lower than the low liquid level, automatic water replenishment will be triggered. When the liquid level reaches the medium liquid level, the water replenishment will stop. When the liquid level reaches the high liquid level, the emergency stop of the test bench will be triggered and water will be drained automatically to prevent the test bench from being flooded and ensure the safety of the test.

[0030] 5. When the fuel cell stack needs to be purged, the reaction gas is not connected to the intake port but to the dry gas port and flows directly out of the outlet without passing through the humidification process, realizing the separation of dry and wet and ensuring the diversity of the experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is an isometric schematic diagram of the fuel cell gas humidifier according to the embodiment of the present invention.

[0032] Figure 2 It is a front view schematic diagram of the fuel cell gas humidifier according to the embodiment of the present invention.

[0033] Figure 3 It is a cross-sectional schematic diagram of the fuel cell gas humidifier according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] As Figures 1 to 3 shown, an embodiment of the present invention discloses a fuel cell gas humidifier, which includes a tank body 1, a heating rod 2, a chuck 3, an intake port 4, a gas distributor 5, a water inlet 6, a drain port 7, a partition plate 8, an outlet port 9, a dry gas port 10, a pressure sensor 11, a first temperature sensor 12, a second temperature sensor 13, a liquid level column 14, a fixing plate 15, a PID controller (not shown in the figure), and a liquid level sensor (not shown in the figure).

[0036] The tank body 1 is welded by seamless 316L stainless steel pipes. It is required that the inner wall of the tank body 1 is smooth and the surface is polished. The interior of the tank body 1 is divided into a liquid area 101, a packing area 102 and an air outlet area 103 from bottom to top. The liquid area 101 is used to store the humidifying solution. The interior of the packing area 102 is provided with a packing layer with a porous structure. The packing layer is made of anti-corrosive metal material. The air outlet area 103 is distributed with a plurality of partition plates 8 arranged in a staggered manner. An air inlet 4 communicating with the liquid area 101 is arranged on the outer side of the lower part of the tank body 1. A gas distributor 5 with a porous structure is arranged inside the air inlet 4. An air outlet 9 communicating with the air outlet area 103 through a multi-way joint is arranged on the outer side of the top end of the tank body 1. The multi-way joint is welded on the tank body 1.

[0037] The heating rod 2 enters the liquid area 101 from the outer side of the bottom end of the tank body 1. The heating rod 2 is fixedly connected with the tank body 1 through a chuck 3 made of stainless steel. The first temperature sensor 12 enters the liquid area 101 from the outer side of the middle part of the tank body 1. The second temperature sensor 13 enters the air outlet area 103 from the outer side of the upper part of the tank body 1. A pressure sensor 11 communicating with the air outlet area 103 through a multi-way joint is arranged on the outer side of the top end of the tank body 1. The pressure sensor 11 is used to detect the internal pressure of the tank body 1. The heating rod 2, the pressure sensor 11, the first temperature sensor 12 and the second temperature sensor 13 are all connected to the PID controller (Proportional-Integral-Derivative controller). The heating of the heating rod 2 is controlled by the PID controller. The temperature of the humidifying solution and the outlet gas temperature are respectively detected by the first temperature sensor 12 and the second temperature sensor 13. Then, the required solution temperature is controlled according to the measured temperature to form a closed loop of temperature control. The heating rod 2 enters the solution to quickly reach the required dew point temperature and pressure. The humidified reaction gas can be directly used by the PEMFC, solving the dynamic response problem generated during the rapid activation and load pulling of the PEMFC and reducing the dew point temperature fluctuation under the condition of a large air volume.

[0038] An inlet 6 and a drain 7 communicating with the liquid area 101 are also arranged on the outer side of the lower part of the tank body 1. Water can be replenished or drained from the liquid area 101 through the inlet 6 and the drain 7 during the PEMFC test.

[0039] A liquid level column 14 is arranged on the outer side of the tank body 1 and communicates with the liquid area 101 and the air outlet area 103 at both ends respectively. The liquid level column 14 is made of a transparent material, which is convenient for observing the liquid level inside the tank body 1 in real time. Liquid level sensors are respectively arranged at the positions corresponding to the high liquid level, the medium liquid level and the low liquid level on the liquid level column 14. Whether the liquid area 101 needs to be replenished or drained and the height of the liquid level can be controlled in real time through the liquid level sensors. When the liquid level is lower than the low liquid level, automatic water replenishment will be triggered. The position of the low liquid level is higher than the lower end position of the heating rod 2 to prevent dry burning. When the liquid level reaches the medium liquid level, the water replenishment stops. When the liquid level reaches the high liquid level, the emergency stop of the test bench will be triggered and automatic drainage will be carried out to avoid flooding the test bench and ensure the test safety.

[0040] On the outer side of the top end of the tank body 1, there is also a dry gas port 10 connected to the gas outlet area 103 through a multi-way joint. When the fuel cell stack needs to be purged, the reaction gas is not connected to the inlet port 4, but to the dry gas port 10, and flows out directly from the outlet port 9 without humidification, realizing the separation of dry and wet, and ensuring the diversity of experiments.

[0041] A fixing plate 15 made of sheet metal technology is welded on the outer surface of the tank body 1. The fixing plate 15 is provided with connection holes, and the tank body 1 can be fixedly connected to the bench by bolts passing through the connection holes, ensuring the stability of the tank body 1.

[0042] Working principle: After the reaction gas enters the inlet port 4, it first passes through the gas distributor 5 and then enters the humidifying solution in the liquid area 101. The gas distributor 5 ensures that the gas can enter the solution evenly; the gas coming out above the solution enters the packing layer, and the packing layer diffuses the gas into tiny bubbles, increasing the contact area between the gas and the liquid in a short time, fully humidifying the gas, and improving the humidification humidity of the reaction gas; and the packing layer can suppress the liquid carried by the large air volume as much as possible, preventing the internal liquid of the tank body 1 from violently sloshing when the PEMFC starts up and activates quickly or the load suddenly changes greatly; the gas passing through the packing layer then coils through the gaps between the partitions 8, further ensuring the uniform humidification of the gas; this structural design ensures that the tank body 1 can achieve a high humidification effect with a smaller volume, and at the same time, the smaller volume of the tank body 1 is also beneficial to reducing the backpressure time during the PEMFC test, ensuring the efficient operation of the PEMFC; finally, the gas flows out from the outlet port 9, thereby humidifying the proton exchange membrane.

[0043] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fuel cell gas humidifier, characterized in that: It includes a tank body, an air inlet, a gas distributor and an air outlet; the interior of the tank body is divided into a liquid area, a filler area and an air outlet area from bottom to top, the liquid area is used to store a humidifying solution, and a filler layer with a porous structure is provided inside the filler area; the outside of the tank body is provided with an air inlet connected to the liquid area and an air outlet connected to the air outlet area, and a gas distributor with a porous structure is provided inside the air inlet.

2. The fuel cell gas humidifier according to claim 1, characterized in that: The fuel cell gas humidifier further comprises a partition, and a plurality of staggered partitions are distributed in the gas outlet area.

3. The fuel cell gas humidifier according to claim 1, characterized in that: The fuel cell gas humidifier also includes a heating rod, a first temperature sensor, a second temperature sensor and a PID controller. The heating rod enters the liquid area from the outside of the tank body, the first temperature sensor enters the liquid area from the outside of the tank body, and the second temperature sensor enters the gas outlet area from the outside of the tank body. The heating rod, the first temperature sensor and the second temperature sensor are all connected to the PID controller.

4. The fuel cell gas humidifier according to claim 3, characterized in that: The fuel cell gas humidifier further comprises a pressure sensor. The outer side of the tank body is provided with a pressure sensor connected to the gas outlet area, and the pressure sensor is connected to the PID controller.

5. The fuel cell gas humidifier according to claim 3, characterized in that: The fuel cell gas humidifier further comprises a chuck, and the heating rod is fixedly connected to the tank body via the chuck.

6. The fuel cell gas humidifier according to claim 1, characterized in that: The fuel cell gas humidifier also includes a water inlet, a drain outlet, a liquid level column and a liquid level sensor. The outer side of the tank body is also provided with a water inlet and a drain outlet connected to the liquid area. The liquid level column is arranged on the outer side of the tank body and its two ends are respectively connected to the liquid area and the gas outlet area. Liquid level sensors are respectively provided at positions corresponding to high liquid level, middle liquid level and low liquid level on the liquid level column.

7. The fuel cell gas humidifier according to claim 6, characterized in that: The low liquid level position is higher than the lower end position of the heating rod.

8. The fuel cell gas humidifier according to claim 6, characterized in that: The liquid level column is made of transparent material.

9. The fuel cell gas humidifier according to claim 1, characterized in that: The fuel cell gas humidifier further comprises a dry gas port, and the outer side of the tank body is further provided with a dry gas port connected to the gas outlet area.

10. The fuel cell gas humidifier according to claim 1, characterized in that: The fuel cell gas humidifier further comprises a fixing plate, the outer surface of the tank body is fixedly connected with the fixing plate, and the fixing plate is provided with a connecting hole.

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