Daikin develops refrigerant for EVs it says lifts range by 50%

[ajdelange]

Air conditioners use the heat generated by compressing the refrigerant to heat and cool the air inside the car. Daikin's new refrigerant has a boiling point of about minus 40 C, 10 to 15 degrees lower than the conventional product. That reduces the power required for compression.

As that paragraph is entirely wrong it is hard to place any faith in the rest of the article.

 

[Crissa]

As that paragraph is entirely wrong it is hard to place any faith in the rest of the article.

Dude, if something is wrong, please explain what and source citations.

We can't learn if we don't know where to even start.

-Crissa

 

[Eye of Elon]

Has anyone seen anything about the "safety" of the new chemical? Does it have a green house gas effect? Is it safe to dispose of? Etc?

If it's half as successful as Freon, I'm sure plenty of environmental concerns will pop up, when the patent is about to expire

 

[ajdelange]

For years the auto industry used R12, an HCFC with Global Warming Potential (GWP) = 10,200, but those got banned by the Montreal Convention, you had to get EPA certified to buy it, you had to recover it from any old equipment etc. The industry then switched to R134a, a HFC considered so innocuous that any Joe could buy it at an auto parts store, the "compressed air" cans you bought at the computer store contained it etc. But it has a GWP of 1300 and so the EU decided that R134a was too bad for the environment too and banned it with the US following this year. Cars built after last year must use R1234yf, another HFC about twice as expensive as R134a but with a GWP < 1 (CO2 = 1). So yes, if this new refrigerant is developed to the point where it is desired by the auto industry we can be sure that it will be subject to scrutiny WRT its effects on the environment.

I've always been intrigued by R744 (CO2) with its GWP = 1. Cheap, plentiful, clean. Apparently several automakers have experimented with it but I don't think any have even considered adopting it. Pressures of over 35 atmospheres are required in the evaporator and over 100 in the condenser (transcritical loop).

 

[Crissa]

...

Thank you for the history of refrigerants, completely unrelated to your prior post.

However, nothing you posted says their statement is incorrect?

R134a has a boiling point of -26C
https://en.wikipedia.org/wiki/1,1,1,2-Tetrafluoroethane
and R1234yf has a boiling point of -30C
https://en.wikipedia.org/wiki/2,3,3,3-Tetrafluoropropene

-Crissa

 

[ajdelange]

Freons (CFC, HCFC) are a scam anyway just use hydrocarbon based refrigerants.

?

But I don't get how it can add 50% more range. The only way the numbers would work is on a small 2 seater city EV thing which uses nearly as much energy for driving as for cooling.

Let's throw some numbers at this. My X takes about 300 Wh/mi for traction at 60 mph. Let's suppose the A/C compressor takes 1 kW (about a ton of A/C) and runs continuously. At 60 mph that's 1000/60 = 17 Wh/mi additional. With a 100 kWh battery I'd have range of 100000/300 =333.3 mi w/o A/C and 100000/(300 + 17) = 315.8. Thus the cost of running the A/C is, at most, 17.5 mi (5%). If I could violate the second law with some new refrigerant which requires 0 energy to compress the most I could recover is 5%. Now at 5 mph my traction load would probably go down to 240 Wh/mi or something like that but my A/C load would be 1000/5 = 200 Wh/mi and my range would be 100000/(240 + 200) = 227. If I could halve the compressor draw 100000/(240 + 100) = 294 which is 67 miles more (30%). So yes, one can hoke up some numbers but as the article was written by someone who doesn't even understand how an A/C works I wouldn't waste too much time thinking about this. Which is exactly what I just did, isn't it?

 

[Crissa]

No one in this thread argued that, @ajdelange . That 50% must be a mistranslation.

-Crissa

 

[Sirfun]

So yes, one can hoke up some numbers but as the article was written by someone who doesn't even understand how an A/C works I wouldn't waste too much time thinking about this. Which is exactly what I just did, isn't it?

Yep.

 

[John K]

Personal takeaway, we can improve range evaluating as a whole instead of focusing on battery and motor. Common sense statement. If I add methane to electrify converters in seats, can I boost my range. You laugh now but, I can eat Mexican more often.

 

[CyberGus]

No one in this thread argued that, @ajdelange . That 50% must be a mistranslation.

-Crissa

I’m assuming they meant “50% improvement in power consumption of existing refrigerants”

 

[ajdelange]

I guess I should add that none of this is to say that Daikin has not identified some substance which substance has steeper isentropic curves on the P-H diagram than does R1234yf and thus requires less energy input per BTU transferred than R1234yf. This would, of course, translate to potential improvement in range both when A/C and heating are required (the latter if the vehicle uses the A/C reversibly). It's just that the range gains mentioned in the article are absurd as is the description of how an air conditioner works.