Stirling/Steam engines, coal fired vehicle engines

Game Talk The Drawing Board
1

This is part suggestion and part query, because to be honest I’d be astonished if t hasn’t been proposed/added before.

Are there any thoughts or established prohibitions against the inclusion of a steam engine/stirling engine vehicle component? It would essentially be an engine that runs off charcoal. It would probably be very heavy and use a lot of iron, as well as producing a lot of smoke and noise and not a lot of power from a single engine, but it would run off easily producible fuel. I mostly see it being useful for base generators, but an old fashioned traction engine would be pretty neat to build perhaps, especially if you added multiple engines to it to increase its power output, turning it into some kind of hellish forest-guzzling, road-train monstrosity.

Ideally it would include some kind of heat-up/cooldown mechanic where its output would increase the longer it’s been running, as well as, in the case of a steam engine, require both water and charcoal to run, but that may be outside the scope of practicality given the limitations of the vehicle system.

In any case I think it would be a neat idea, I might have a look at the vehicle files and see how difficult it would be to mod in. Unless someone already has?

2

Its probably not in because, simulating a steam powered car is not as easy as an internal combustion one, and more importantly, finding gasoline is still much cheaper than making coal.

From my point of view they would be vastly inferior to the other renewable path (electric). Not only is electric much more efficient but getting fuel for it only requires you to wait, and perhaps swap batteries, instead of having to cut trees and burn them.

Although the two engines could work well for power generation when solar is unfit.

3

I’ll re-quote my post about steam engines and wood gasifiers.

I like the general idea, because this sounds like one of those things you'd reproduce quickly after the world died, but I know nothing about automobile steam engines (only few bits about the huge, ultra-bulky power plant ones).

If someone did the necessary research and listed it in a readable format, I could help or even write it myself.
I’m looking for things like:

How to feed the boiler: automatic system or having a tar-covered man shovel in broken planks? How often?
Water (or any other working fluid) use and reuse: open or closed system? Clean water or any water? How much water used?
How to regulate output: some sort of super/turbocharger increasing/limiting oxygen input?
How to clean it after usage? Can it work as a continuous process?
Heating up: do the mechanics (other than power output) change before it gets ready to use?

Also, DYI solutions much preferred and nothing that requires an actual factory. When in doubt, assume that most of the technology in the game is like it is now in real life, rather than human-shaped robots running on energy provided by internal thorium reactors.
Some of the ideas can (and possibly should) be simplified, but realism is a bonus.

As for wood gasification, it looks like it would play less nicely with the current system than steam engines. The whole heating up with different fuel and re-using existing engines but limiting their output. I may be misreading things, but I think steam engines would be better here.
But again, I know next to nothing about wood gasification.

I’d say one or the other, because their in-game effect is pretty much identical (push wood, acquire torque).

Though it probably would run on wood and not charcoal. Charcoal mass production is quite work-intensive, even with the constructed kilns that work on 500 volume batches.

4

Advantage to steam engines is torque, last I knew. Unfortunately we don’t currently model the difference between getting stuck in the swamp and pushing on through, so ATM it’s not hugely useful.

5

another advantage to steam is the scale: you can make these pretty big and this is easier than doing the same with internal combustion engines.

So if for any reason cata needs a really big engine (faction factories, trains, very big electrical generators), a steam engine would cater for it with less problems in the technical expertise needed (efficiencies today are 30-45%, so make 'em 10-15% for custom built) and with easy to find fuel.

PS.
While we are at it, consider turbine engines too:
Relatively easy to build, even small turbine engines are very powerful and the technology is well-known.

Not used too much in automotive since its inefficient (10-15% vs the 55+% of a diesel).
They are used in the military though, to generate lots of power for some tanks (Abrams, T80) and ships, either as a sole engine, or to complement diesels for when extra power is needed.
Also, they are used in electrical power generation as a quick way to produce power to supplement the steam/nuclear/whatever else plants, stand-alone or in combined cycle plants.

And of course, a variation of turbine engines is also used in aviation, so they will have to eventually get added for airplanes.

6

[quote=“jcd, post:5, topic:8804”]While we are at it, consider turbine engines too:
Relatively easy to build, even small turbine engines are very powerful and the technology is well-known.[/quote]

They’re far harder to build than any kind of internal combustion engine, in both effort and required parts tolerance.

7

The main holdup on adding steam engines is the requirement for them to consume both a fuel and a working fluid (usually water). The way engines are modeled in game doesn’t support this, so you’d need to overhaul some of the vehicle code to make it happen.

[quote=“jcd, post:5, topic:8804”]PS.
While we are at it, consider turbine engines too:
Relatively easy to build[/quote]
[citation needed]
I couldn’t find anything indicating that hand-crafting a turbine is feasible. The resources I did find indicated that it requires heavy machining with very tight tolerances, precisely the kind of thing that is uncraftable in game.

“have to”, you’re funny. I doubt we’ll ever add functioning aircraft.

8

Presumably due to z-level issues? It’s possible to make a working helicopter-like thing on motorcycle engines, in a garage, with a box of scraps, so it would be within realm of possibility in CDDA.

Or a hot air balloon.

9

well, sure it ain’t gonna happen before z-levels, but eventually why not? One can dream :slight_smile:

[quote=“Kevin Granade, post:7, topic:8804”][quote=“jcd, post:5, topic:8804”]PS.
While we are at it, consider turbine engines too:
Relatively easy to build[/quote]
[citation needed]
I couldn’t find anything indicating that hand-crafting a turbine is feasible. The resources I did find indicated that it requires heavy machining with very tight tolerances, precisely the kind of thing that is uncraftable in game.[/quote]

It all depends on what you mean by a ‘turbine’

Modern aviation ones are really high tech, using very advanced engineering and material science, an automotive/marine turbine is also hard to fit due to transmission problems (turbines operate in excess of 10,000 rpm and even at 100,000 rpm)
BUT, a simple turbine for power generation is not that hard to understand or make.

Well, a turbine is a very simple thing really:
It is basically a wheel with fins, much like a fan, through which hot pressurized exhaust gas pass. The gas makes the turbine rotate at high speed.
The input air is compressed by a compressor (powered by the turbine) before it goes to the burning chamber, from which the exhaust gas goes to the ‘turbine’ for power generation at high pressure and temperature.

Both the ‘turbine’ and the compressor are ‘turbines’. This means they are fans, more advanced than a windmill or waterwheel, mainly in two aspects:

  1. They have different sized fins, starting small and getting progressively larger (or the reverse, depends on if they decompress or compress the air) in order to depressurize / pressurize the air in an optimal way. Usually they have many stages of different sized fins.
  2. The materials needed for the turbine have to withstand temperatures around 1500-1800 oC in pressures of 60bar or more. This is critical as the higher the temperature and pressure, the higher the efficiency.
    The problem that makes today’s turbines beyond a survivor’s reach is here: You can make metal fins, but they will get destroyed pretty fast at those temperatures. Also your tubing would have to withstand that pressure.

Now, let us consider what one man can do:
Assuming he is a very good mechanic (9+), would anyone really doubt that its impossible to make a compressor & decompressor out of steel? I mean, they are just fins welded around a rotating axle.
Then weld those in the same axle and put each inside a casing so that there would be no air leaks?
Also make a combustion chamber get fed air from the compressor, fuel separately, burning them well and feeding its exhaust to the turbine?

If he made it work at, say, 600-700 oC (iron will melt over 1100 C and up to 1500 C depending on the iron) and maybe 5-10 bar, there is no reason why he could not achieve this. Efficiency would be of course about 5% or so.
Application for vehicles would be almost impossible due to transmission problems (how do you hand-craft a transmission for 10,000 rpm minimum? conventional gasoline cars do a max of 6-9k rpm) but it would be useful for massive electricity generation.

Is it still arguable that such a contraption is harder to do than a traditional steam engine? Pistons are harder to make than fins. It is only the operating temperature & pressure that makes modern turbines problematic.

References in general about turbines:
Turbine: Turbine - Wikipedia
Gas turbine: Gas turbine - Wikipedia

Also, i found lots of references of people that created a turbine by using a car’s turbocharger.
A turbocharger is a compressor/turbine set that its job is to pressurise the fuel/air mixture inside the piston. The power for the compressor is given to it by the turbine who rotates due to the exhaust gases of the engine. (So in actuality it is a pre-built compressor/turbine set and what most of these people do is making it work independently by adding a combustion chamber.)
Still, why not craft it from scavenged turbo engines? Much smaller but 2-3+ times better efficiency.
Or even from to-be-added power plants and aircrafts? (sure, aviation turbines work a bit different from the others)

References:
http://aardvark.co.nz/pjet/faq.htm

http://www.gp3.co.uk/Build.htm
http://diyturbinejet.com/

10

[quote=“jcd, post:9, topic:8804”]Modern aviation ones are really high tech, using very advanced engineering and material science, an automotive/marine turbine is also hard to fit due to transmission problems (turbines operate in excess of 10,000 rpm and even at 100,000 rpm)

Assuming he is a very good mechanic (9+), would anyone really doubt that its impossible to make a compressor & decompressor out of steel? I mean, they are just fins welded around a rotating axle.[/quote]
When a power transfer component rotates “…in excess of 10,000 rpm…” the word “just” starts to be misapplied.

IMO, on both cases, steam and turbines, you could make a tiny one(power-wise) work. To make a large one, that doesn’t rip itself apart, you’d need a foundry and machining. Those could be very do-able for a survivor as a long term project, but why on earth would you do something like that, when you have a pretty much inexhaustible supply of fuels, solar panels and even more high-tech solutions.

11

[quote=“jcd, post:9, topic:8804”]It is basically a wheel with fins, much like a fan, through which hot pressurized exhaust gas pass. The gas makes the turbine rotate at high speed.
The input air is compressed by a compressor (powered by the turbine) before it goes to the burning chamber, from which the exhaust gas goes to the ‘turbine’ for power generation at high pressure and temperature.[/quote]

This is kind of right, kind of wrong. A lot of it depends on what exactly you’re talking about, since there’s no such thing as just a ‘turbine’ engine. An engine like on an Abrahms is a turboshaft, an aircraft engine is a variety of turbofan (or turboprop I guess), etc. They have some significant differences. Since we’re talking about engines that are intended to be stationary and provide mechanical power, we’d probably start from the turboshaft.

The turboshaft operates (in general) by taking pressurized ambient air and combusting it, which turns the main shaft. This shaft in turn powers the actual pressurization (the compressors you mentioned) while also providing mechanical output (and since the exhaust isn’t the source of thrust, it aims to eat up as much energy from the exhaust as possible). You might notice a chicken/egg problem here, where the shaft needs to be turning already to start pressurizing and combusting the air, and that is exactly how it is in many cases - the normal solution is some kind of power source that can provide initial power to the engine (electric or hydraulic or whatever) to get that shaft up to the minimal speed to be able to run. An auxiliary power unit, a start cart, or (if the engine is designed for it), a special compartment to emergency start by putting basically a grenade into it.

And that ties into the tolerance issues - to provide the awesome power that these engines can provide, they need to operate at high RPMs. And when you have multiple layers of fan blades spinning around at tens of thousands of RPMs, things like fan blades having a slightly different weight or shape will rip the engine apart - it’s not that the survivor can’t make the fins, it’s that we’re talking about a world where the tolerances on items are measured in thousandths of inches on complex curves larger than your arm. They have an incredibly fine tolerance. And unless you’re just repairing an existing engine (which is alone probably more than the average survivor could ever figure out), you have to tackle the fluid dynamics design issue of how the air moves through the engine and through the fan blades and reacts to the injection of gas. That’s not trivial, at all. That’s “teams of engineers who have been doing nothing but this for a combined time of decades” to achieve. Then you have other issues - to transmit that power, you need either a separate power shaft that can rotate at a different speed than the compressor shaft or a gearbox able to convert the variable shaft speed into a usable power source (or both). When making a variable transmission is probably going to be the easier choice, it’s not an easy choice at all. (Even if you want to use it just for electric power generation, you’d still need to solve the transmission problem.) There’s also a pile of other non-trivial issues, like how to inject fuel into a combustion chamber that’s that hot without having an explosion (remember that in internal combustion engines the gas is injected during the ‘cold’ part of the stroke and these engines have no such thing).

And because you NEED those high RPMs to achieve the power, and those high RPMs NEED the high temperatures and pressures involved in modern engines, there’s no way to just ‘make it smaller’. It doesn’t scale linearly. You can’t throttle the max RPMs in half and get half the power and call it a day.

These are examples of people making things other than turboshafts - these engines all use the exhaust as raw mechanical power, like a turbojet. They are VASTLY different than a turboshaft, and would be utterly useless for anything that wasn’t providing thrust or fire, and the amount of thrust they provide is almost certainly miniscule.

Yes.

EDIT: and like I mentioned above, even maintenance (not repair, just maintenance) of jet engines that are OEM installed is something I’d consider to be beyond the capability of survivors unless there are specialized backgrounds added where they have significant experience as a pilot or an A&P mechanic and also have access to the maintenance manuals.

12

Yes.[/quote]

ok, i guess you did not read this part of the wiki article on amateur gas turbines.

If amateurs are able to make these things today, why not a really good mechanic after the cataclysm, with lots of spare parts and time to use.

Anyway, i suggested to consider adding these things as powerful electrical generators and scavengable tank/marine engines.

Still this is correct:

I wouldn’t try to craft any kind of engine when there are all these stuff ready to be scavenged.

I might retrofit and use a scavenged gas turbine engine or a steam engine if i could though, the first because of its awesome power for its size/weight and the second because of its cheap fuel.

PS. Yes, i’m aware (and will not elaborate on) the difference between aviation and conventional gas turbine engines. I was mostly speaking about the conventional one, since i cannot think of a good way to use an aviation one. Still, the aviation’s compressor/turbine set today is used as a part of the ‘turboshaft’ engines, so these could be used as spare parts.

PS2. Well, it is apparent that noone believes this, but i still maintain (and can bring more references on this) that a turbine engine is in principle one of the simplest engines available, is cheaper and relatively easier to build (in relation to engines of the same power output), and has much lower maintenance costs than other comparative engines. Their main drawbacks are: atrocious efficiency, difficulty of using rotary motion with such great rpms, and their loudness, but those are not a real hindrance to a survivor…

13

I guess you did not read anything I posted, since you still seem to not actually realize there’s a difference between making something that can blast hot air and making something that can provide controllable mechanical power.

They aren’t. There’s an incredibly tiny amount of people that use these things (outside of things like the model airplane industry or people doing it for low power giggles). They’re able to, with a significant amount of knowledge and expertise and backing from the larger manufacturing/repair industry, assemble and operate these things and sometimes tweak them. Don’t confuse ‘amateur’ in this context with ‘hobo welding scrap metal together in his garage’.

Nobody believes it because because literally nothing in this is true.

You seem to think that this:

is the same thing as this:

Images should be fixt! For some reason the latter was displaying fine on my screen, I assume something something ~cacheing~ as the reason.

14

Second picture is hotlinking forbidden, try direct link instead.

EDIT (Thanks Flame): Click the link, delete the g off the end, re-add the g, go to link. Gets around that all the tiiime. Usually.

15

Nope, that’s broke too.

16

Just like to add that the majority of difficulty with most engine types right now isn’t the idea of them (I would totally love to see a steam engine, etc.) but is rather the code end of things. The current engine/vehicle system just doesn’t have a good way of handling multiple engine types/fuel types right now, and it’s a bad enough pain to add more to it that you might just be better of doing a small rework so that you can add them more easily.

17

you seem to think that this:

is what i claim that someone can build just from scrap.

What i was thinking was something much much cruder, like the Elling’s turbine engine (Ægidius Elling - Wikipedia)

as for advantages/disadvantages of turbines compared to other engines, a reference:
http://www.ustudy.in/node/9926

anyway, time to drop this conversation.

18

jcd: You seem to be equating “build” with “scavenge parts for”, that is what your links seem to be directed at at least. Sure if you start with an automotive turbocharger you could make a small (really small, toy really) turbine, and if you can find an existing turbine (locomotive, marine, etc) you might be able to make repairs to it and maintain it. You’re getting a lot of pushback because you seem to be saying building one from scrap is reasonable, it’s simply not.

Also, you do realize you can’t make any kind of other engine either? It doesn’t matter if a turbine is theoretically simpler than a reciprocating engine, you can’t make either in the game. I find the idea of building a piston-based internal combustion engine to be just as out of reach as building a turbine, neither is within the reach of a lone survivor.

19

yep, i am not sure how i went into arguing about it when i know already that the only craftable engine is a low-power electric one.

plus, they are super rare in automotive applications so scavenging one would also be far-fetched.

so, i have to apologize for going into this discussion…

over and out.

20

There is such a thing as a stirling engine, which works without a liquid component.

The main drawback appears to be difficulty in scaling it up, as opposed to steam and steam turbine engines which can obviously be built extremely large if needs be.

It seems to be quite a practical device which would run off any contained heat source, it would seem to be fairly ideal for early, low power devices (its operations is mechanically simpler than the internal combustion engine) as well as for long term power production for bases, if you can’t find any solar panels/don’t have a secure outside area for them. Another interesting quirk is that, if supplied with mechanical power and run in reverse, it can function as heat pump, making it a method of creating refrigeration. Thus making it a potential crafting ingredient in the production of refrigerators, or alternatively, scavengable from them (or possibly more likely, from building AC systems). They also have the advantage of being well within the sort of crafting area that the game covers. If someone can forge a sword, build a bionic, or construct a pneumatic bolt driver, this sort of device would seem to be within their ability to construct.

Mostly it just seems odd to me that there is no simple, automatic, mechanical power generation method. The new foot crank + alternator is nice, but I can’t do anything else while running it. Gasoline engines are good but doing a run for gasoline can be quite dangerous early on, even if I have quite a bit of mechanical skill, and I’d also rather save it for cars. Rationing precious fuel is a good mechanic, but electric cooking is essentially a simplification of something I can already do with wood and charcoal, just with fewer keypresses. Being able to convert things over into vehicular electricity and utilities, works wonders for ease of use, especially with the nice new wiring options for bases.

It’d be nice to have an engine I can just fill up, and leave it running to give myself electricity whenever I want it. That’s a fun thing to set up and gives a definite distinct feel to base-living as compared to roughing it in the wilderness.