HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
Page 1/4  >  >>
naperlou
User Rank
Blogger
Going back
naperlou   3/8/2013 10:12:01 AM
NO RATINGS
Chuck, is there any reason they just don't go back to a known battery technology?

Charles Murray
User Rank
Blogger
Re: Going back
Charles Murray   3/8/2013 10:20:26 AM
NO RATINGS
As far as I know, naperlou, the only reason to use lithium-ion is the energy density. Higher energy density means they can cut weight, which is of course always important in aircraft design.

Gorski
User Rank
Platinum
787 batteries need liquid cooling
Gorski   3/8/2013 3:01:44 PM
NO RATINGS
The solution seems to be liquid vs. air cooling. The article states that air is less dense at higher altitudes and is less efficient in cooling anything even though it's at a lower temperature. Volt has gone to liquid cooling that works. What is Boeing waiting for? Call the GM engineers and find out what they did. A Volt did go on fire a little while ago.

Charles Murray
User Rank
Blogger
Re: 787 batteries need liquid cooling
Charles Murray   3/8/2013 4:29:38 PM
NO RATINGS
Yes, Gorksi, it's a matter of liquid versus air cooling. It's also a matter of passive versus active cooling. As far as we can tell, Boeing is using passive air cooling. There reportedly are no fans to draw the hot air away. Toyota uses air cooling on its Prius PHV, but it is active air cooling -- they use three fans to draw the heat away from the battery's cells.

Cabe Atwell
User Rank
Blogger
Re: 787 batteries need liquid cooling
Cabe Atwell   3/8/2013 4:56:36 PM
NO RATINGS
My friend's PC in water cooled, every component. If that slacker can do it, I don't see why Boeing can't do the same.

C

Charles Murray
User Rank
Blogger
Re: 787 batteries need liquid cooling
Charles Murray   3/8/2013 6:34:38 PM
NO RATINGS
I don't know how much it would cost to add liquid cooling, Cabe. In today's electric cars and plug-in hybrids, packaging is said to be about 50% of the cost of the entire battery package. How much that differs between passive and active cooling situations, I don't know. Whatever the cost, though, the production volumes for a 787 are ridiculously small compared to those of a production car, so the cost wouldn't be multiplied by hundreds of thousands of units.

g_ost
User Rank
Gold
Re: 787 batteries need liquid cooling
g_ost   3/9/2013 3:18:56 AM
NO RATINGS
Liquid cooling is not my favorite solution. The thermal energy developed during lithium ion battery charge discharge cycles should be just moved away from the source. To obtain an efficient thermal energy transport the use of heat pipes will bring much more benefit. In case of battery thermal runaway the water system will be a big, big problem.

a.saji
User Rank
Silver
Re: 787 batteries need liquid cooling
a.saji   3/10/2013 9:07:16 AM
NO RATINGS
@g_ost: Good point mate. Do you think liquid cooling has an dangerous affects?   

g_ost
User Rank
Gold
Re: 787 batteries need liquid cooling
g_ost   3/10/2013 11:25:38 AM
NO RATINGS
Thermal runaway occurs at 120 -200 deg. Celsius, is a strong exoterm reaction which can not stop until all active material is consumed. Actually is the liquid electrolyte which starts decompose. The only commercial available technology able to transfer more than100 watt/ cm2 is the heat pipe. Boeing should have experience with this technology. It was extensive in the spacecraft technology to cool the sunside of a spaceship (transfer the heat from the hot to the cool side). More than that the heat can be transferred to a heat exchanger outside the battery walls (trough the firewalls). Another system should be also included to cool down the cells at bellow 20 degrees Celsius where the liquid electrolyte ions stop to move (available for the military technology). This approach is possible to be implemented with special designed hot pipes at reduced volumes. The space for the cooling pipes (integrated into cooling plates between the cells) is the same as with the current (empty space between the cells) Boeing solution. Yes, Walter can be dangerous, if water comes in contact with battery electrodes the battery will explode.

Elizabeth M
User Rank
Blogger
Re: 787 batteries need liquid cooling
Elizabeth M   3/11/2013 8:00:54 AM
NO RATINGS
You've been all over this story, Chuck, and it seems like it will continue for awhile. Great coverage. I agree that it seems to be a liquid vs. air debate. Perhaps some of the latest research I've covered about lithium-ion battery design could be helpful in terms of what best way to design the battery so this doesn't happen again. I guess it's a little too late to start from scratch, though, so Boeing will have to fix the problem based on what it's already done.

Page 1/4  >  >>


Partner Zone
Latest Analysis
Hacking has a long history in the movies, beginning with Tron and War Games and continuing through The Girl with the Dragon Tattoo.
In a move that strengthens its 3D design business, Stratasys continued a 15-month buying spree this week by announcing its plan to acquire GrabCAD, a provider of a cloud-based collaboration environment for engineers.
Feature-advantage-benefit could help engineers in how we approach design problems, how we sell our ideas to management, and how we market ourselves when it comes to jobs.
Many diverse markets take advantage of semiconductor IP; so many that no one can recite the entire list without leaving off several. So why do we track all the vertical markets? They all have a unique set of requirements and value attributes differently. One major vertical market segment is automotive.
Adam Berger hacked a computer keyboard into a mini key-tar to play with his band.
More:Blogs|News
Design News Webinar Series
9/10/2014 11:00 a.m. California / 2:00 p.m. New York
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
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Sep 22 - 26, MCU Software Development A Step-by-Step Guide (Using a Real Eval Board)
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: September 30 - October 2
Sponsored by Altera
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