I've gone through the NTSB's interim report, Jeffrey, and there's no reference to earlier high temperatures, so I can't answer the question. For what it's worth, though, The Wall Street Journal reported that the temperature during the JAL incident hit 1,250 degrees F.
Heh...heh. Yeah, but if the ins. co. found out that you flew knowing the published issues/dangers, they might not honour the claim, many don't cover suicide!
I was thinking that instead of cooling or smoke venting systems, they should just make a break away battery with a trap door and drop it out the bottom of the aircraft, that'd do it right? It could catch fire at anytime then. Let's face it, how many times do we actually need only battery power... :-) Yeah, the battery burning at terminal velocity through moist air is kinda like a meteorite. Funny, mention an idea like that and everyone would laugh, but venting smoke is a viable cure?
But those extra large windows and extra cushioning with wine holders in first class sure makes me feel better about flying the DLiner.
I'm dubious even about the need for liquid cooling in a case like this. Correct me if I'm wrong, but do we even know that the cells reached a high temperature PRIOR TO the fires? This is critical. I assume the battery management system monitors the cell temperatures. If it does, and the cells had reached a high temperature, I'm guessing this would have been announced already. And if the problem occurred without a prior high temperature, then something else, presumably internal to the cell that caught fire, was the cause, and liquid cooling would be superfluous.
Liquid versus air cooling? The present battery has no effective cooling system of any kind as far as I can tell. The case provides conductive cooling and any outside air provides passive convection cooling of the case and that is it. The cells could bake each other with no effective cooling within the battery.
Boeing needs to maintain the energy to weight ratio. So, no other battery chemistry or more complex cooling system is practical for their design goal. Internal heat pipes connected to a cold plate on one side of the case could help reduce internal cell temperature but would add weight and would most likely require active cooling outside the case. So, it looks like they'll be opting for a more fireproof containment, more space between cells and maybe an external venting system to keep the case from rupturing and smoke from pouring into the cabin. Band-aid approach?
This alone will not prevent catastrophic battery failure but will permit them to live with occassional battery failures without endangering the aircraft. Or at least that's what they may be hoping for. The time bought will permit them to eventually phase in a full redesign of the battery system. That's what I'm hoping for.
The engineers and inventors of the post WWII period turned their attention to advancements in electronics, communication, and entertainment. Breakthrough inventions range from LEGOs and computer gaming to the integrated circuit and Ethernet -- a range of advancements that have little in common except they changed our lives.
The age of touch could soon come to an end. From smartphones and smartwatches, to home devices, to in-car infotainment systems, touch is no longer the primary user interface. Technology market leaders are driving a migration from touch to voice as a user interface.
Soft starter technology has become a way to mitigate startup stressors by moderating a motor’s voltage supply during the machine start-up phase, slowly ramping it up and effectively adjusting the machine’s load behavior to protect mechanical components.
A new report from the National Institute of Standards and Technology (NIST) makes a start on developing control schemes, process measurements, and modeling and simulation methods for powder bed fusion additive manufacturing.
If you’re developing a product with lots of sensors and no access to the power grid, then you’ll want to take note of a Design News Continuing Education Center class, “Designing Low Power Systems Using Battery and Energy Harvesting Energy Sources."
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.