What are your thoughts on the fact that 90% of the comments here are something to the effect of “there is no sense in personally investing in using Tables since google will shut it down in x years”?
341 karma · joined August 16, 2019
I believe engines make less power when the air in is hotter too as there is less delta T. Something something Carnot cycle
I don’t do enough miles a year boating to care about the minor amount of fossil fuels I burn. I would be really interested in the foil tech with gas powered outboard. The foil boat must be must much more fuel efficient with a gas motor?
Read the Wikipedia page, sure the system operators in MISO didn’t get some alarms but blaming the whole thing on that is pretty lame. There were multiple causes and not Getting alarms was just one of 10 things that went wrong.
FYI where I’ve worked the tiers of loads are metered individually and picked up in order of priority and with a check to verify the combined capacity of the generators which are online is great enough to pick up the load. Likewise loads are shed in order if there isn’t enough generation such as one generator tripping.
I don’t really see that much difference between opening a breaker and bad quality power. It is the same sensing and logic in both cases: is the magnitude and frequency of the phase to phase voltages in the acceptable range or not?
You can test the system’s ability to detect loss of power or poor quality power by lifting sensing wires or injecting out of frequency or voltage range power with a test set, and load pickup and load testing we used a load bank. The actual hospital load is fed through bypass breakers during these tests so if the utility went out we would have to manually operate breakers to disconnect the load bank and swing the vital loads over to the generators.
If I am setting up electrical protection on a generator I don’t put a short circuit on the generator, I show the protection relay what it would see by injecting current and voltage with a relay test set and make sure the relay gives the signal to open the breaker when it should.
Greenfield hospital generation sites are straightforward to open the utility feeds since the vital loads are still fed through the old power system.
I’ve built and programmed control systems that do all this with multiple generators, multiple utility feeds, and multiple tiers of loads of different priorities.
Diesel generators for hospitals and water pumps for fire suppression systems are generally set up with very loose settings as it is clearly worse for a patient to die or a building to burn down than to destroy a machine, and this requirement is in the specifications.
The heavier it is also requires bigger more expensive bearings and accompanying system to get the thing spinning in the first place.
I looked at a flywheel that spun at 12,000 rpm. It was going to be located in an underground vault in case it ever got off its pedestal bearings it wouldn’t mow people down.
Like anything that stores energy but doesn’t generate the economics aren’t great.
These days a web based NNTP client could offer an equivalent if not superior experience.