11:53 a.m. - 2005-05-08
don't trust anyone
why you can't trust anyone...
Steam lab thursday - the last one of the year. It's the one day a week where we get to go into our real live power plant and burn fuel, produce steam, replace faulty parts, test our equipment, electronics, water quality and safety trips, and just generally try not to blow shit up. We use the steam to run a few different turbines, generating both AC and DC - in theory we could feed our AC into the grid, but in practice we lack a) the synchronizing equipment, and b) the expertise. We also send some (sometimes all) of our steam to the physical plant - that's the department responsible for heating the campus, and providing all the hot water. They have their own nice big boilers, so we don't make much difference either way, but it's nicer than just wasting it.
So we get assigned different tasks, and off we go, firing the boiler, getting the feedwater moving, starting the oil pumps - the usual. SuperIrritatingCompulsiveKeenerBoy (let's call him sickboy, for short) goes bouncing off the walls towards the water softeners, and comes back approximately 8 seconds later to tell us he opened everything up and that there's feedwater flowing into the condensate tank. Great, we say. Thank you, we say. Why don't you go do something very important and time consuming over on the other side of the plant, we say, and we start filling the boiler. Great. About an hour in, between other tasks, we notice that one of our water levels is reading awfully low. No problem, we just blew down that whole line, there *ought* to be condensed water in it from the steam, but there isn't yet, so it isn't reading properly. We get the hose, fill the line. Hmmm... doesn't seem to have fixed the problem... start at the boiler and work our way backwards, but not fast enough, as we ended up tripping the boiler on low water. Nice safety feature, that one. Anyway, by this time we've traced it back to the deaerator, upstairs. (does exactly what you'd think; takes air out.)(of water) It's empty. Momentarily thrown off course, we decide the problem must lie in the feedpump which transfers water from condensate tank to deaerator, and indeed, it doesn't seem to be moving any water. But wait. It's moving no water because a) there's only about 20% in the tank for it to move, and b) that water is so hot that as soon as it hits the low pressure area in the pump, it flashes into steam. You can't pump steam. Ok. Checking every feed into the tank, we find 2 that are *far* too hot; the condensate line from the boiler, which ought to be hot, but not so hot you can't touch it, and... the incoming feedwater. Since it should be pumping cold city water in from our water softeners, the only reason it would be hot is because steam is feeding backwards towards the softeners. (it gets stopped by check valves, but still heats up the lines.) *sigh* Off we go towards the softeners, where a 5 second check shows us that there's no flow. A second hand-check confirms it. The flow-meter (a lot like the hydro meter on the side of your house, and just as easy to read) isn't moving. The pipes are all warm, not cold. There's high pressure on the inlet side, no pressure on the outlet side. We have no idea what sickboy did over there, but it wasn't what he said he did. We grumble a little, ignore his protests, put one of the softeners into service, open the inlet and outlet valves, and confirm flow in the three ways I just mentioned; flowmeter, pressure gauges, and a rapidly cooling piping system. Then we fill the appropriate vessels and fire the boiler again. As soon as we get it up to pressure, we shut down for the day. So far every steam lab we've tripped the boiler on a different safety interlock, just to make sure they're all working - low gas pressure, low water, high water, no air, no flame (there's a neato little flame scanner for that, which we unplug) - stuff like that. We also have, in our lab, three emergency shutdown buttons, in case of... well... emergency. Kerel decided to shut down on "you stupid idiot!", and as we all looked at him in confusion, he casually leaned against the wall, hitting the e-stop. Alarms, lights, and our prof, smiling, and jumping in with "you stupid idiot"! We shut off the alarms, shut down the boiler, and went home. And we learned a few things, chiefly "never trust your coworkers, as they might be like sickboy".
