Why are heat pipes not used in PEM fuel cells?

In summary: It seems that the technology just hasn't been explored yet. I'm not sure if it's a power density or technical limitation issue.
  • #1
Topher925
1,566
7
Just curious as to why you don't find heat pipes or any passive cooling in larger PEM type fuel cells. I have seen them used in methanol fuel cells but not FCs for hydrogen. Is there a good reason for this? Is it because the power density of fuel cells is typically higher than that in many others or is because the technology just hasn't really been explored? Any input would be greatly appreciated as I really need a solid answer for this question.
 
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  • #2
Anyone?
 
  • #3
I am curious to know the answer to this.

Are you sure there are no embedded water/air cooling plates between each fuel cell?

I can only take a stab at this problem by saying if the PEM fuel cell is operating at high current densities, it is going to produce a lot of water. Perhaps the excess heat is being used to evaporate the H20 at the cathode to prevent back diffusion. But then again, they have to keep the electrolyte membrane hydrated so they have to remove the heat or they're putting in more water as its input.
 
  • #4
makethings said:
I am curious to know the answer to this.

Are you sure there are no embedded water/air cooling plates between each fuel cell?

I can only take a stab at this problem by saying if the PEM fuel cell is operating at high current densities, it is going to produce a lot of water. Perhaps the excess heat is being used to evaporate the H20 at the cathode to prevent back diffusion. But then again, they have to keep the electrolyte membrane hydrated so they have to remove the heat or they're putting in more water as its input.

Cooling systems are used in almost all fuel cells. For medium to large cells this usually consists of channels integrated into the bipolar plates of each FC in the FC stack. Water or some heat carrying fluid is then pumped through those channels in order to regulate heat and temperature. Heat pipes however do not operate on this principle. Heat pipes are passive devices that work by phase change of a the working fluid sealed in the heat tube. Not only are heat pipes passive but they have an extremely high heat flux compared to other methods of thermal management. I've found a lot of patents for heat pipes in PEMFCs and a couple papers for methanol fuel cells but nothing for larger hydrogen PEMFCs.
 

1. Why are heat pipes not used in PEM fuel cells?

Heat pipes are not used in PEM fuel cells because they are not compatible with the operating temperature range of the fuel cell. Heat pipes are designed to transfer heat between two points within a specific temperature range, typically between 20-150°C. However, PEM fuel cells operate at much higher temperatures, ranging from 80-100°C. Additionally, the presence of fuel and oxidant gases in the fuel cell can also cause corrosion and damage to the heat pipes.

2. Can heat pipes improve the performance of PEM fuel cells?

No, heat pipes cannot improve the performance of PEM fuel cells. In fact, they can hinder the performance by reducing the efficiency of heat transfer and adding additional weight and complexity to the fuel cell system.

3. Are there any alternative ways to manage heat in PEM fuel cells?

Yes, there are alternative methods for managing heat in PEM fuel cells. These include using cooling plates, heat exchangers, and active cooling systems such as fans or pumps. These methods are specifically designed for the high operating temperatures and corrosive environment of PEM fuel cells.

4. What are the potential drawbacks of using heat pipes in PEM fuel cells?

Some potential drawbacks of using heat pipes in PEM fuel cells include increased weight and complexity of the fuel cell system, decreased efficiency of heat transfer, and potential corrosion and damage to the heat pipes from exposure to fuel and oxidant gases.

5. Can heat pipes be used in other types of fuel cells?

Yes, heat pipes can be used in other types of fuel cells that operate within the temperature range suitable for heat pipes. However, each type of fuel cell may have different requirements and limitations, so it is important to carefully consider the compatibility of heat pipes with the specific fuel cell system.

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