Boilers in real life / Rankine cycle for dummies

[cube]

Is there someone on the forum who knows how water pressure looks around boilers in real life?
This picture shows pretty much the steam engine I'm talking about: https://en.wikipedia.org/wiki/File:Rank ... layout.png.

The way I imagine a pipe, when you have a pressure differential between two points in it, there water flows there and
pumps create pressure differential around themselves (lower pressure in front of the pump, higher pressure after the pump).
Now, the part I don't understand is what a boiler does. When the water is heated up, I think that it should increase pressure, but i also imagine a boiler as some sort of a fancy pipe, with no direction different from the other. So how can it increase pressure on the hot end without causing it to reverse the flow?

This is not directly related to Factorio, although some day I'd like to change the current pipes to be more realistic.

[kovarex]

Hi, we have been talking about this with Tomas, and searched how actually the pressure system works in real power plants.
From what I understood, there must be one way valve, and there must be pressure from the outside, that presses the water through the ventil to the boilers.
The pressure could be achieved by having high cylinder of water.
http://www.duke-energy.com/about-energy ... ed-how.asp

[cube]

Meh ... I should learn to read, that wikipedia article is pretty good

Process 2-3: The high pressure liquid enters a boiler where it is heated at constant pressure by an external heat source to become a dry saturated vapour. The input energy required can be easily calculated using mollier diagram or h-s chart or enthalpy-entropy chart also known as steam tables.

[ficolas]

wow I was thinking about this yesterday :O

[Aarkreinsil]

What about convection and stuff like cooling towers?

I've taken a tour through the coal power plant in our city once, and it was a frickin maze of pipes. They mostly extended upward from the boilers, the boiler chamber actually being the tallest building in the region, afaik.
Also the pressure inside the cooling towers was enormous, opening one of the doors at the side we had to push a guy with two people to get him into the (working!) tower. I admit I didn't have the balls to go inside, and you couldn't see a thing in there, but the people who have entered it seemed to be all fine and dandy when they came back out. Was surprised to see that it wasn't actually thaaat hot inside.
They also suck in air from beneath, creating something like rain that is then collected in a huge pool at the bottom. That would be nice as a transition from steam -> water, if you are going for closed circuits.

Dunno if everything is 100% correct, since it's been a couple of years, but maybe you could just try contacting a local power plant for some info? Maybe see if you can take a tour yourself? Might be a fun pastime and quite informative for your development purposes.

[tonberrytoby]

What about convection and stuff like cooling towers?

Convection and Cooling towers are only an enviromental protection measure.
You can just dump the old hot water in the river and withdraw new cool water form there. That kills all the fishes, but factorio guy doesn`t eat anyways.

[Aarkreinsil]

What about convection and stuff like cooling towers?

Convection and Cooling towers are only an enviromental protection measure.
You can just dump the old hot water in the river and withdraw new cool water form there. That kills all the fishes, but factorio guy doesn`t eat anyways.

With the new pollution mechanics that wouldn't be all too desirable, though. And at some point you might heat up the water so badly that it starts evaporating altogether, or enters the system too hot or something, depending on the size of the lake.

[RawCode]

all steam based devices work same way, including reactors.

also picking new water without reusing steam will cost hurge amount of energy, as you may know, heating up water to 300degree cost large amount of energy, reusing already 100-200 degree water better than picking 30degree from lake.

ps. all devices feature HEAVY pressure, at that pressure water wont turn to steam ever at 250 degree.

[Psycho0124]

Now, the part I don't understand is what a boiler does. When the water is heated up, I think that it should increase pressure, but i also imagine a boiler as some sort of a fancy pipe, with no direction different from the other. So how can it increase pressure on the hot end without causing it to reverse the flow?

Yeah, it's really interesting how it all works. The boiler is at very high pressure when operating, and it would force the water out of the feedwater line if not for some mechanical wizardry going on at the boilers feedwater line. They sometimes use hefty high-pressure feedwater pumps to force water into the boiler but most are equipped with a steam-driven feedwater injector and a small low-pressure feedwater pump after the condensor. The injector sprays a small jet of high-pressure steam through a series of nozzles, imparting its momentum to the cold low-pressure input water as it goes and drives it into the high-pressure boiler through a check-valve.

The key to understanding how it works is to appreciate that steam, having a much lower density than water, attains a much higher velocity than water would in flowing from a high pressure to a low pressure through the steam cone. When this jet of steam meets cold water in the combining cone, the principle of conservation of momentum applies. The steam is condensed by mixing with the cold water but the flow of water is accelerated by absorbing the momentum of the high velocity water molecules condensed from the steam. Since the steam, in condensing, gives up its latent heat energy, this causes the temperature of the resultant jet of water to be raised. When this accelerated jet of water passes through the delivery cone, it is capable of developing a much higher pressure than that of the original supply of steam and is thus able to overcome the boiler pressure at the check valve, thereby allowing water to enter the boiler.

source: http://en.wikipedia.org/wiki/Injector#F ... _injectors