Supermarket Power backup?

[mxslick]

I read from time to time about flywheel-generator UPS systems, but I've never seen one. You?

Nope, I haven't. Closest I came to anything like that was an up-close inspection of the launch catapult drive for the roller coaster "Montezuma's Revenge" at a theme park I worked at. Something like a 50-ton flywheel spun up by a very large 4kV motor. I have an interesting story about that, but that's another thread..

On the large stores it takes a about 700 to 800 KW for a restart during a hot day. And that is the load, not Gen set size.

Wow. That explains the clearly heard groan from the store's padmount when the feeder came back on.

Thanks Bob for all the info, and to everyone else for their input. I always learn a lot from y'all here.

 

[LarryFine]

If you had access to more than a single nugget of dry ice, you could load up a pickup and take it home to toss in the pool.

It's fun to drop a piece into the toilet during Halloween, too.

 

[mdshunk]

My kids used to order a fruit punch thing at a Polynesian restaurant that must have had dry ice in it. It came to the table steaming and smoking.

 

[Lcdrwalker]

Here in Ohio, our Kroger stores and most Meijer stores have a small generator for electronics and emerg. lighting in addition to the individual UPS and battery back up systems. If power is out for more than an hour, the refrigerated cases with doors are locked. Insulating blankets are used on open cases.

 

[peter d]

Insulating blankets are used on open cases.

That makes a lot more sense than the plastic and duct tape that our big chain here uses.

 

[winnie]

We were looking at flywheel systems as energy storage to provide power for short duration tests. As I understand it, the flywheel systems are intended to provide about 30 _seconds_ of backup time. The idea is to give you enough time to bring another backup system online, or to improve the life of battery systems.

If you squeeze metal against a chunk of dry ice it makes cool noises.

Inert gas asphyxiation is probably one of the most painless ways to go. I am told that because you keep inhaling and exhaling you don't actually _feel_ like you are asphyxiating. No warning, no fear. Just pass out and die. CO2 will at least give you some warning, because it will trigger your breathing reflex and make you feel short of breath. NASA has lost a number of people who have walked into nitrogen purged rooms and passed out before they knew that there was a problem.

-Jon

 

[wireguru]

Nope, I haven't. Closest I came to anything like that was an up-close inspection of the launch catapult drive for the roller coaster "Montezuma's Revenge" at a theme park I worked at. Something like a 50-ton flywheel spun up by a very large 4kV motor. I have an interesting story about that, but that's another thread..

do tell! ive ridden that thing.......

 

[frenchelectrican]

I read from time to time about flywheel-generator UPS systems, but I've never seen one. You?

Marc S., I did see few of them they are not too bad at all if set up right and yes they will carry over during powerfailure useally anywhere from 20 sec to 3 min depending on size and setup.

It more common to see the flywheel UPS being doubleended set up it wil take a little bit of power to bring it up the speed but once it stay at the speed the power useage is very little just like keeping the batteries charged.

Merci,Marc

 

[mxslick]

do tell! ive ridden that thing.......

As soon as I figure out the proper section of the forum to start that thread, I will..

 

[dbuckley]

I read from time to time about flywheel-generator UPS systems, but I've never seen one. You?

Theres a few rotary UPS systems in the City of London, from Piller Power Systems.

In the pic above, that round thing on the left is the energy storage unit, the thing is a motor with a really heavy rotor and a flywheel, that whizzes round, and when the power fails it becomes a generator.

On the right is a motor generator, so the motor-generator delivers the power normally, when the utility drops the flywheel power keeps the motor generator running. This will cover a short power outage.

Heres the even cooler version, which I've not actually seen in real life:

On this the motor-generator is now horizontal, and on a shaft with a diesel engine, via a slip clutch. So when the utility power fails, the motor generator continues to spin with energy provided from the flywheel generator, as noted above. On power failure the diesel starts up, and takes the load mechanically. Then, and this is the clever bit, the motor part of the motor-generator can be re-purposed as a generator. In data centre applications the main motor-generator is sized for the IT load, and the "extra" generating capacity of the re-purposed motor element is used to run the A/C. So you have non-stop IT power, and short break A/C power.

The Piller rotary UPS is a cool and very reliable system. I would take them over batteries every day. Of course, there is a cost to using these things, but, the best always costs.

 

[wirenut1980]

IMO, a motor generator set with a flywheel is the best for protection against all types of disturbances from the utility. 2nd best is an online rotary ups, true sine wave output. The best overall reliability setup I have ever seen was at Midwest Independent System Operator (MISO) control building in Indiana. I can only think of one way that building loses power...if the earth opened up below it, and it fell...into the Center of the Earth...it may still have power even after that.

 

[mxslick]

dbuckley, thanks for that post and link!! Fascinating equipment for sure.

An update:

The local POCO still has no idea what caused the outage in my OP. All they have admitted to was that a feeder relayed that night. Duh....