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Condensing Steam Turbine


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Turbines are currently poorly balanced, but fairly easy to get running with door pumps or exploits. I do not like door pumps or exploits however and have been exploring designs which condense the steam for transport instead. This is easy in concept, but the execution is not practical or worth doing right now. What follows is a proof of concept to illustrate what needs to be changed for condensing turbines to become worthwhile.

The simplest way to go about such a turbine design is to use external cooling (from a slush geyser or cold biome for example) and then reheat the water into steam. This is wasteful and requires an excessive amount of cooling (about 4.8 MW or 400 wheezeworts worth) and heating. Not worth pursuing.  Using a closed cooling loop to recycle the heat pulled out of the steam improves efficiency. The simplest version of this requires about 6 aquatuners and thus an excessive amount of power. Again not worth pursuing. To decrease the aquatuner count, I used 2 large counter flow heat exchangers. This becomes excessively large, but the only real solution IMO. The following build is power positive, uses no exploits, and requires relatively less external cooling/heating.

 

5b48749f5aa65_CondensingTurbine.thumb.jpg.363cd20d079609ce751c3d9a7356a4c1.jpg

Spoiler

5b4874b92304a_CondensingTurbinePlumbing.thumb.jpg.1298b4944b6e855180dc1248a1f92da8.jpg

 

Due to "cold side" steam coming out at about 215C (turbine heating the 150C output steam) and aquatuners overheating at 175C, it is not possible to recycle all the heat back into the system.  About 1.9 MW of external cooling is still required, this is represented by a sieve cooler on the right. This heat and the about 7MW of heat required to run the 2 turbines is provided by the magma system on the left. 

Everything else is best explained by downloading the save and watching how it works.

Condensing Turbine.sav

 

Things Klei can do to make this design more practical:

1) Make the turbine transfer less or no heat to the output steam. This would lessen or omit the external cooling requirement.

2) Lessen the steam throughput. 10 kg/s is much too much. A smaller throughput means a simpler and smaller design and less heat needed to run.

 

TLDR:

Download the save, it's neat.

 

Edit:

 This one is old and busted. There is a new version down below.

 

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13 minutes ago, wachunga said:

Things Klei can do to make this design more practical:

1) Make the turbine transfer less or no heat to the output steam. This would lessen or omit the external cooling requirement.

2) Lessen the steam throughput. 10 kg/s is much too much. A smaller throughput means a simpler and smaller design and less heat needed to run.

I have a smaller design which I built for the same reason, I do not like using doors, gasses and blocking the tiles.

Downside to my build is that it is NOT a run 24/7 build, I "think" it could be if i was not an idiot and used normal water as my coolant... I think the biggest problem with my design would be keeping the coolant cool, My design doesnt really struggle with the amount of steam consumed though as I bottle all of the pressure up until it is needed, I will post a build of it once I find a volcano in my current build, maybe you can improve on it or shoot it down.

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Yeah a build that doesn't run 24/7 eases a lot of the burden of doing something like this and potentially opens new avenues of approach. For example, a crude -> NG boiler actually produces heat because of specific heat differences. One could calculate the extra heat made and use an intermittent turbine to destroy that heat with power produce as an added bonus. The extra heat could just be allowed to build up or alternately sequestered elsewhere and reintroduced when the turbine is running.

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The problem with my build that I can imagine being an issue later on is that the steam can become super heated, I thin k this only happens if it sits without running for a long time, I am thinking that if this happens maybe I will put a sensor so if the system begins getting too hot whilst is it on standby it will turn on to purge the steam (Yes I would be losing energy for nothing but better than bursting my pipes XD)

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Very cool build.

If only the devs tested the steam turbine out in the same way to see if it was viable. The same goes for a functional solar panel build (that doesn't require constant regolith removal by dupes). I hope they go back and fix both before the next update. Each time they add things to the game that don't work just adds useless bloat. I still love the game but I wish they took their tests beyond functional testing to viability testing.

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I like heat exchanger builds so this one is definitely up there as one of the more interesting ones! I see you've split up flows of the petroleum cooling/reheating loop to cover more area, I wonder if the exchanger's efficiency could be improved by having condensing and the reheating steam flow through snake tunnels and using a single long radiant pipe...

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Try it! I'm quite interested in new ideas or optimizations I overlooked.

Several things went into the decision for a wide exchanger. The longer the exchanger becomes, the more pressure is required at the start of it. Right before the steam condenses, it's pressure is about 1.2 kg/tile. To achieve that requires about 10 kg/tile at the exit of the 2nd turbine. Which requires about 14 kg/tile at the exit of the 1st turbine. I've found that higher pressures on either side of the turbine means more heat transferring through the turbine, which means more heat to get rid of. The opposite of this can be observed with the temperature sensor I use in the magma section. Only 80g of chlorine is used to greatly reduce the heat transferring through to the wheezewort. This increases the temperature range I can precisely control.

So it's a trade off between a longer more efficient exchanger and more heat to exchange (and ultimately lost without creating power). I haven't fully explored the optimal design as it becomes tedious after awhile.

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1 hour ago, wachunga said:

I've found that higher pressures on either side of the turbine means more heat transferring through the turbine, which means more heat to get rid of. The opposite of this can be observed with the temperature sensor I use in the magma section. Only 80g of chlorine is used to greatly reduce the heat transferring through to the wheezewort. This increases the temperature range I can precisely control.

So it's a trade off between a longer more efficient exchanger and more heat to exchange (and ultimately lost without creating power). I haven't fully explored the optimal design as it becomes tedious after awhile.

You're right, I just tried putting 2 tiles of steam next to each other, one at 100 C and the other at 200 C. I tried this with 2 kg pressure and with 20 kg pressure. At first it looks like the 20 kg version equalized slower but rather suddenly I found them both to be equal at 150 C.

That does point towards wide exchanger and keeping pressures low... And of course since the goal is to avoid door/gas exploits that allow the turbine to run, we can't use doorpumps to achieve low pressures while still having a long exchanger.

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On 7/13/2018 at 3:32 AM, wachunga said:

it is not possible to recycle all the heat back into the system

This statement *is* true but there are a few ways you can get a lot closer. Sorry I can't demo a build. I lose interest the instant I turn on debug mode, I'm a working professional, and each attempt takes a really long time in survival mode :)

Two very strong ways come to mind that you can get closer to having no direct cooling, (you can never completely eliminate it of course) & recycling a very high percentage of the heat in your steam cycle. #1 below circumvents the aquatuner thermal limitation you described.

#1: Build a system where the only equipment your high temp liquid touches are pipes and maybe a liquid vent. Tricky but there are a few ways. All your flow valves, pumps, and aquatuner have to touch warm liquid only, and send hot liquid directly back to the boiler section where it'll cool down a bit. If you need to cool hot liquid just mix it with warm liquid in a tank, and pipe *that* to your aquatuner. You can keep dumping 200C liquid into a 95C tank, the aquatuner will regulate your tank temp happily as long as it's not operating directly on 200C liquid. Might require some redesign so you can change exactly what your aquatuners are doing.

#2: to recapture the largest percentage of the cycle's heat for re-use, a double-tube heat exchanger is probably the best possible configuration. There are certain challenges, like pressure, flow, & heat transfer balancing, but a double-tube setup has much higher efficiency.

What you built is referred to a "tube shell" heat exchanger. You can get pretty good efficiency with that but there will be some imperfection (mostly, you lose a small amount of delta T on each phase change i.e. the system consumes&rejects more heat from the heat source on each phase change than a double tube configuration)

 

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Blocking the input of the steam turbine to 1 square fixes the throughput problem. I’m pretty exploit conscious and I wouldn’t call that an exploit.

You can recycle heat by taking 135 degree oil and pre cooling your 215 degree steam to a more manageable 150. Then, use the 150 degree oil to turn the water you recycled back to steam. You might be able to get away with 105/120 degree oil, but I haven’t tried that.

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You use 150 degrees to preheat your steam. You still need a good size quanitity of 280 degree steam from some heat source.

bay 1: 125 degrees heating system for boiling or reboiling water

insulation letting steam through slowly (door system that are only open if steam on other side is >270)

bay 2: 280 degree steam heating system

door only open if pressure in bay 3 is < 8000

bay 3: perfect for steam turbine with optional minor heating

steam turbine

bay 4: cooling to 150 (or maybe less)

bay 5: condensation

bay 6: pump the water back to bay 1

 

I should make a save for it. It’s pretty efficient and doesn’t feel like cheating.

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Attached is no-cheat turbine using condensation and heat reclamation to optimize the heat usage. It uses heat from a magma source as well as a comet source. There's lots of room to add more heat sources. I've run it for a few cycles to let it stabilize. It's probably better demo'd powering a base.

I don't use any abyssalite in this build, since - new patch incoming.

Notes on adding heat sources:

  • If it's greater than 300 degrees, add it to the top bin
  • If it's an temp ~>200 degrees, add it to the middle bin (middle heating)
  • If it's >140, you can it to the lower bin (water pool)
  • If it's a guaranteed temp, you don't need as many shutoff valves

I do some door trickery, but only to reduce heat transfer between bins. Steam has pretty low conductivity, so maybe it's not needed if you arrange temp shift plates better. Especially if you expect the system to have high throughput - very active.

No cheat steam turbine.sav

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Took a second to realize that to get your turbine to start working, you have to make sure the automation wire connected to the battery fires positive. The turbine then putters on/off/on/off because of over pressure (I'm guessing because we need more heat). I bet we can use the Super Coolant to rapidly liquefy the steam (shrinking your build), and bring heat to the chambers below.  The new Super Coolant will reduce the size of tons of builds.

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I think the space around the turbine will still be needed, since condensing it quickly causes two problems:

  1. Less heat reclamation. That's what the first wave of circulating pipes is for. Those pipes could carry more heat if they were made with supercoolant, but since they already carry all the heat - meh.
  2. Less room for the steam to expand - gas moves so slowly and giving it 3 directions to move in is super useful.

I did the math on this setup. A pipe of petroleum at ~300 degrees getting cooled by 50 degrees is actually not enough to keep a steam turbine running constantly. Each pipe like that is around 880 kdtu/second. Steam turbines eat somewhere between 1000 kdtu to 6400 kdtu based on what I've seen. If you cap off the bottom to one tile, you can get to the lower end. If you keep the temperature and pressure just barely able to run it, that also keeps things on the low end. Even so, you'll need more than one petroleum pipe feeding the thing. One supercoolant pipe could keep it running - although two might be needed if you're looking to delete more heat while keeping it running.

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24 minutes ago, Nickerooni said:

I think the space around the turbine will still be needed, since condensing it quickly causes two problems:

  1. Less heat reclamation. That's what the first wave of circulating pipes is for. Those pipes could carry more heat if they were made with supercoolant, but since they already carry all the heat - meh.
  2. Less room for the steam to expand - gas moves so slowly and giving it 3 directions to move in is super useful.

I did the math on this setup. A pipe of petroleum at ~300 degrees getting cooled by 50 degrees is actually not enough to keep a steam turbine running constantly. Each pipe like that is around 880 kdtu/second. Steam turbines eat somewhere between 1000 kdtu to 6400 kdtu based on what I've seen. If you cap off the bottom to one tile, you can get to the lower end. If you keep the temperature and pressure just barely able to run it, that also keeps things on the low end. Even so, you'll need more than one petroleum pipe feeding the thing. One supercoolant pipe could keep it running - although two might be needed if you're looking to delete more heat while keeping it running.

Since we know that the turbine spits out steam at 160C and needs, at least, 225C steam in order to run, then, at the bare minimum, with the whole bottom of the turbine uncovered and pulling through 10KG/s of steam, it destroys 2,716,350 Joules/DTUs every second.  

 

65C x 10,000 grams x 4.179 = 2,716,350

 

Of course, it's impossible to feed the turbine 225C steam because the turbine passes heat through it to the cooled steam it just used, reducing the temperature of the hot steam.  So, its more along the lines of 3 Million DTUs of energy or more to keep one constantly running.  For super coolant, that's about 35~40C (About half of the difference in steam, which makes sense because its SHC is about half of super coolant)

 

So, if super coolant was fed in at around, oh about 275C..?, a single pipe of it should be able to keep a turbine running.  I guess it just depends on how fast the heat can be transferred from the coolant, to the pipe, and finally the steam.

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I've made a new version utilizing the new materials as well as some design improvements.

5bbb668b56073_CondensingTurbine2a.thumb.png.d1bfd5f35f8251fb6f1c821369e790cd.png5bbb66961edab_CondensingTurbine2b.thumb.png.7423dfb929a68caca927492423979b71.png

Two heat exchangers, the outside one pulls heat out of the steam and condenses it. The inner one dumps heat back into the water/steam. You can't make a perfect heat exchanger so the aquatuners provide the extra kick needed to get the cooling/heating loop back to it's initial temperature. Valves are used to throttle the super coolant such that it's heat capacity matches that of the steam (4.950 kg/s * 8.44 10 kg/s * 4.179).

Gold is used for the turbine. Due to heat transfer mechanics, gold's low SHC reduces the heat bleeding through the turbine. I overlooked this in the original version. Instead of outputting "cold" steam of about 215C, a gold turbine gives about 195-200C. Also note the tile walls containing the turbine, this is to prevent steam flowing through the turbine and picking up heat.

The bit of plumbing in the upper right supplies the water to prime the system, about 4600 kgs. I didn't bother mocking up the heat/cold source and instead used diamond tiles to simulate that (top and bottom right). The 2 lower sections of radiant pipes in the condenser aren't necessary in normal operation. The steam condenses before it hits that line of bridges in the middle, the radiant pipes are there to catch any stray steam from startup.

As you can see the new materials allow the design to be substantially smaller, to the point that I would consider it reasonable to build in survival. I also managed to cut the heat wasted to external cooling down to about 1 MW. Doing so and the better efficiency of super coolant reduces the power consumption of the aquatuners to about 950 W. So power positive with just the one turbine.

However it still requires a ridiculous amount of heat, roughly 4.3 MW (1 MW to external cooling and 3.3 MW to the turbine) or about 3.5 volcanoes IIRC. Not at all practical. The 10 kg/s steam throughput is a killer and Klei needs to change it. Still pretty neat if you ask me.

Condensing Turbine V2.sav

 

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Gold turbine. Nice call. I’ll try that.

If you only need 1MDTU of external cooling, why not put the steel aquatuner inside the steam and run supercoolant so that you only need one? That way, you only need 2.3 MDTU of incoming heat, since you get to substract the heat you pushed in your system.

How much heat input does your setup get if you block off inputs to the turbine? My guess would be it’s better than the one I posted. Although, I should switch to gold and see what happens!

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6 hours ago, Nickerooni said:

If you only need 1MDTU of external cooling, why not put the steel aquatuner inside the steam and run supercoolant so that you only need one? That way, you only need 2.3 MDTU of incoming heat, since you get to substract the heat you pushed in your system.

How much heat input does your setup get if you block off inputs to the turbine? My guess would be it’s better than the one I posted. Although, I should switch to gold and see what happens!

The second version was made before the steel aquatuner change. After the change I did a version putting the steel aquatuner inside the steam like you say to eliminate the need for external cooling. I didn't bother posting it due to the rapid changes going on, once everything settles down a bit I'll update this thread again. It's essentially the same thing, just adjust the piping so you can squeeze the aquatuner in below the turbine and above the reheating exchanger. Good call.

Blocking 4 of the inputs brings the steam usage down to 2kg/s, heat required would be something like 650kW. That's about a minor volcano IIRC. The turbine deletes at a minimum 75C of heat, * 2kg/s, * 4.179 SHC. The challenge would be to control the heating such that steam going into the turbine is right at the minimum required (226.9C). Assuming you are doing this for energy production. If you just want to delete heat, then dump all the heat into the system you can.

 

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@wachunga I found out a no-cheat way to get down to 2 kg/s output for 2000W without blocking any tiles. It still costs ~3-4 MDTU/s to keep running. So, it's still a huge heat hog. Stack the turbines and, here's the important bit, intentionally get the heat to transfer to the output steam. Use whatever you want. Diamond shift plates. Thermium shift plates. Cycling fluid behind the turbines. If you stack 5 of them, with the intention of only 1 running at time, you get only 2kg/s output at the top. Maybe you could stack more, but I'd be hard pressed to get the a 250 degree heat source to bleed heat up through more than 5 turbines. And, you don't want the heat source too hot in order to minimize the DTU requirements.

With your setup, that means you need significantly external cooling. A fifth.

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2 hours ago, Nickerooni said:

@wachunga I found out a no-cheat way to get down to 2 kg/s output for 2000W without blocking any tiles. It still costs ~3-4 MDTU/s to keep running. So, it's still a huge heat hog. Stack the turbines and, here's the important bit, intentionally get the heat to transfer to the output steam. Use whatever you want. Diamond shift plates. Thermium shift plates. Cycling fluid behind the turbines. If you stack 5 of them, with the intention of only 1 running at time, you get only 2kg/s output at the top. Maybe you could stack more, but I'd be hard pressed to get the a 250 degree heat source to bleed heat up through more than 5 turbines. And, you don't want the heat source too hot in order to minimize the DTU requirements.

With your setup, that means you need significantly external cooling. A fifth.

Do you block the steam flow between the towers? I obviously don't mean turbine tile blocking. I mean if you dont let steam pass except through turbines. Also is it nessecairy or beneficial to automate the turbines based on pressure/heat?

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7 hours ago, Nickerooni said:

@wachunga I found out a no-cheat way to get down to 2 kg/s output for 2000W without blocking any tiles. It still costs ~3-4 MDTU/s to keep running. So, it's still a huge heat hog. Stack the turbines and, here's the important bit, intentionally get the heat to transfer to the output steam. Use whatever you want. Diamond shift plates. Thermium shift plates. Cycling fluid behind the turbines. If you stack 5 of them, with the intention of only 1 running at time, you get only 2kg/s output at the top. Maybe you could stack more, but I'd be hard pressed to get the a 250 degree heat source to bleed heat up through more than 5 turbines. And, you don't want the heat source too hot in order to minimize the DTU requirements.

With your setup, that means you need significantly external cooling. A fifth.

Rather than overheat the bottom and let the heat bleed up through the stack, it would be better to just add more heat between each turbine.  But then, why not just cycle the steam back down instead of running through multiple turbines and then condensing it?  Also how are you getting it to only use 2kg/s without blocking 4 of the input tiles?

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