HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
News
Electronics & Test

Were the Boeing 787 Batteries Cooled Properly?

NO RATINGS
< Previous Page 2 / 2
View Comments: Newest First|Oldest First|Threaded View
<<  <  Page 2/6  >  >>
g_ost
User Rank
Gold
Operative ambient temperature range -18 to +65 Celsius
g_ost   1/30/2013 10:28:21 AM
NO RATINGS
An active heater could be also required!!!

ervin0072002
User Rank
Gold
Re: Donít jump into conclusions
ervin0072002   1/30/2013 9:40:52 AM
NO RATINGS
I guarantee you that was not expert advice. Protection circuits are placed to insure that the amount of power drawn from a battery allows for safe operation. True we would like to have active cooling but:

Can any one guess the cost of heat sinks?

The added weight because of the heat transfer unit?

The cost of the delivery of Air, water, or fluid flow through the device (added weight as well)?

The cost of developing and testing the equipment so that it will not impact safety of the system during operation in the event of a failure?

 The cost of maintaining the equipment?

No I don't think there is any logic in the claim that active cooling is required simply because other systems tend to use it. Best and cheapest way is to hire an engineer specializing in thermal characteristics of that device and insure that heat rise of the internal components does not pose a threat to the system and limit power draw that way. You supply more deep cycle power for less weight (weight is a major factor in aviation and duration of emergency operation) and insure that your device has passive cooling. This is a guess and it seems that the end design goal to this battery was this. I have dealt with devices that require active cooling in the airframe (I specialize in the hottest part of the airplane the engine). Testing components that require active cooling is a long stretched process. The analysis of the heat transfer unit alone could easily become a 1000 page report. Not to mention the cost added to the unit.

g_ost
User Rank
Gold
Re: Donít jump into conclusions
g_ost   1/30/2013 5:18:46 AM
NO RATINGS
1 saves
I checked the CT scans made by NTSB and I'm surprized to see the deformation of the individual cells. The protective cell case looks weakly designed when the requirments for aeronautical applications include strong external pressure variations. I would say also that the large terminals could initiate case cracks during battery assemby or life time.

I would not tip on battery manufacturing process issues much more on battery cell integration solutions. It looks like a poor engineering solution.

Marvin McConoughey
User Rank
Iron
Re: Batteries, not composites
Marvin McConoughey   1/30/2013 4:24:01 AM
NO RATINGS
You hit on the long term problem.  The composites have not had enough in-use time to verify long term durability.  Accelerated testing, which has been done on the types of composites used in aircraft, is useful, but not definitive. The best accelerated testing is achieved when the results can be checked against a known record accumulated in the actual operating enviroment.  That has not yet been possible at the depth and scale of the current expansion of composites usage.

Charles Murray
User Rank
Blogger
Re: Donít jump into conclusions
Charles Murray   1/29/2013 7:29:34 PM
NO RATINGS
It's true that we don't know yet what current or voltage was going in or out of the battery. But electronic battery management -- i.e., protection against overvoltage and overcurrent -- by itself is not considered sufficient for cooling of a big lithium-ion battery, the experts told us. "Just having protective circuits is fine, but it's absolutely insufficient," Elton Cairns of the University of California said when we asked him. "There's no avoiding the generation of a certain amount of heat. Ant time you operate a battery, heat is generated." It's worth noting that all automakers who use lithium-ion batteries also also use battery management ICs to monitor voltage, current and charging rate. But even while they use battery management ICs, they also all use cooling systems -- either liquid-based or air-based.  

Dave Palmer
User Rank
Platinum
Re: Batteries, not composites
Dave Palmer   1/29/2013 6:10:56 PM
NO RATINGS
@Ann: On the other hand, a pessimist would say that the battery problems are just keeping the planes from accumulating enough flight time for the problems with the structural composites to become apparent yet.  Fix the battery problems and get the planes flying again -- for long enough to get some fatigue cracks going -- and pretty soon you'll have structural components failing.

I'm not saying that I necessarily endorse that view, but that's the way you need to think if you want your designs to work.

Elizabeth M
User Rank
Blogger
Re: Overheating?
Elizabeth M   1/29/2013 3:46:05 PM
NO RATINGS
I am with you on this, but obviously something went wrong. Even in the most careful design, sometimes there are unforseen problems. Then again, it's pretty well known that lithium ion batteries can overheat and possibly explode...so I guess it will take awhile before we know the real story.

Elizabeth M
User Rank
Blogger
Re: Batteries, not composites
Elizabeth M   1/29/2013 1:57:04 PM
NO RATINGS
Ah, I did miss that, Ann, thanks for filling me in. So then did Boeing make the necessary changes to fix any problems with composites?

Ann R. Thryft
User Rank
Blogger
Re: Batteries, not composites
Ann R. Thryft   1/29/2013 12:55:03 PM
NO RATINGS
FYI, Elizabeth, in case you missed it, there was a lot of criticism of composites in aircraft early in the game last year due to some minor problems with the 787's composites, as well as composite issues with some Airbus planes.

naperlou
User Rank
Blogger
Re: Donít jump into conclusions
naperlou   1/29/2013 11:08:57 AM
NO RATINGS
William K, you bring up a good point about specs and suppliers.  Unless you do a lot of quality control on those suppliers, you open yourself up to potential problems.

Years ago I was at a spacecraft manufacturer.  We had a ball bearing lab.  Yes, ball bearings.  These are used in gyroscopes, reaction wheels and other mechanisms.  We did start to contract that out, but the quality was so bad that we brought it back in house.  It was that important.  Not long ago I talked to a local manufacturer of components for industrial machinery.  His supplier convinced him to take some foreign made ball bearings.  Well, they failed in customer installed equipment in a matter of months.  He could test for most things, but did not have the facility to test for hardness.  Guess what the problem was?

I could go on and on about companies that I have consulted with that contracted out manufacturing and were burned by it.  Generally the smaller companies go out of business.  Boeing's experience with the 787 is a cautionary tale.  An aircraft manufacturer is not just a brand and design house.  Some of the people posting here have said they would not fly in a 787.   These are informed people.  Boeing has some work to do.

<<  <  Page 2/6  >  >>
Partner Zone
Latest Analysis
Watch as we teardown Amazon's Fire Phone -- the company's first smartphone, designed to compete with iOS, Android, and Windows Phone devices.
Lithium-ion batteries will soon back up the power grid on the Hawaiian island of Kauai, providing the stability to handle intermittent power fluctuations from renewable energy sources.
A relative newcomer to the 3D printing market has developed a 3D printer that can use five different materials in multiple colors for customized creations.
These free camps are designed for children ages 10 to 18. Attendees are introduced to 3D CAD software and shown how 3D printers can make their work a reality. Many classes were nearly 50 percent girls and 50 percent boys.
Take a look through these film and TV robots from 1990 through 1994.
More:Blogs|News
Design News Webinar Series
7/23/2014 11:00 a.m. California / 2:00 p.m. New York
7/17/2014 11:00 a.m. California / 2:00 p.m. New York
6/25/2014 11:00 a.m. California / 2:00 p.m. New York
5/13/2014 10:00 a.m. California / 1:00 p.m. New York / 6:00 p.m. London
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Aug 4 - 8, Introduction to Linux Device Drivers
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6


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.
Next Class: August 12 - 14
Sponsored by igus
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service