Frequently asked questions

The inlet coolant temperature is limited to 60 degrees C, which is assumed due to the close approximation to power electronics circuit. Is it a particular problem if the inlet coolant temperature rises above 60 degrees C?

It would be possible, but it depends on how efficiently you are operate the radiator. For example, for the FCM50 higher inlet temperatures would lead to derating of the full power output. Many applications don’t need max. power all the time, since most load profiles show dynamic power demands. Derating will be only applied if the max. power output is requested for several minutes.

Regarding the testing campaign, which testing procedure are you applying for your durability test as there is a lifetime target of 15.000 hours foreseen. Which cycles do you use?

The test protocol are currently being defined. Durability testing is a tricky one and is currently being discussed within the consortium.

The standard specifies that fuel cell modules can be oriented two ways. Does that require changes within the fuel cell module?

Yes, it does, for example for the position of the drain

Why does the standard not provide requirements for electrical connectors?

We have had lots of discussion within the consortium. The allocation close to the fluids is considered unwanted, but it is something that we will review this at the end of the project. Initially, we also considered the proprietary nature of electrical connectors. A general problem is that each supplier has its own connector types which most of the time are not compatible to each other. Choosing one connector would be put one supplier in favour. This cannot be done within an EU funded project. Just cable lugs are “compatible” but they need more installation space.

Do you then need a standard specification for coolants? This process is currently under development within standardisation bodies?

Yes, that would be great as long as the stack module and fuel cell module manufacturers give their green light

Currently, ongoing standardisation work is being performed for coolants. Would there be an interest to use the same type of coolant for fuel cells or during testing? Would it be considered sensible to develop such one solution for this modules?

Stack module manufacturers are specifying there own needs for coolants. But looking from a standardisation perspective, it would be great to have standard cooling for fuel cell modules suppliers and end-users too

For several application, OPC-UA is used as a digital standard and not SAE J1939. This seems to be the new industrial standard. Why are you using SAE J1939?

Alternatives to SAE J1939 have been discussed within the consortium, however SAE J1939 was the preferred solution. This has to do with the use in the mobility, industrial and maritime sector.  In particular for mobility SAE J1939 has a good chance of being adopted in a significant market.

If you are using SAE J1939 it is an old standard and you are not able to enter the market with it. The marine sector is heavily looking into OPC-UA?

We also have to be pragmatic. It is difficult to find a controller that can fulfil all functions. Industry will use OPC-UA, but in mobility you don’t use a PLC but an embedded controller, and controllers for J1939 are readily available. For other applications it may be necessary to use a gateway for the communication with the FCM