Railcraft Boiler Heat Up Time

[Keldor]

So I want to make a few boilers, and I've calculated how many my tree farm can support. The problem is, they take quite a while to heat up, so I don't know what sort of fuel reserve I'll need to get through before fuel usage stabilizes at max temperature.

Does anyone have the equation for the rate at which a boiler heats up? Failing that, any figure for a 3x3x4 tank more accurate than "a few hours" would be very helpful.

 

[Peppe]

These are some notes i took on a 36 HP boiler i started up:

I counted methane cells used -- no outside production.

Start 8 stacks 512

Cells used = temperature in C

256 = 220 C
384 = 316 C

+4 stacks into system = 768

512 = 418 C
640 = 522 C
768 = 614 C

+4 stacks = 1024

896 = 726 C
1024 = 810 C

+4 stacks = 1280

~ 1200 = 1000 C

20 stacks of methane cell est heat value = 23 million.

Methane cells have a heat value of 18000. You can use that to compare the numbers above to your fuel of choice. Like peat's 2k heat = 18k/2k = 9 times the fuel needed over methane cells. So about 180 stacks of peat to go from 0 - 1000. If your farm has just enough production to maintain the final fuel usage you probably want to have about half the total needed for the initial start-up. Works out a double chest + regular chest full of peat.

For peat i think you need 3 peat farms for the 36 HP boiler, so you might need a little less storage for start-up as the 3 farms over a few hours will make a lot of fuel.

I should have tracked the real time it took to startup as well, but it was over several play sessions. 3-4 hours game time i would say.

 

[Captain Neckbeard]

If you fill every fuel slot it has with full stacks of Coal Coke, you still won't be all the way up. You'll be getting there, though.

 

[ShneekeyTheLost]

How about "Several Hours'?

Seriously, you want to do the math? Here's the equations, straight from the Railcraft Wiki:

• Base Fuel Usage Per Tick (base) = ( (6.4 - numTanks * 0.08) / ( 16 LP or 8 HP ) ) * numTanks
• Heat Adjust Fuel Usage Per Tick = base + base * (8 - 8 * heat%)

Maximum Heat on a HP boiler is 1,000C

The only tricky variable is rate of increase. I'm fairly certain the rate of increase is not constant, it declines as it gets closer to being fully heated up. At about half-way heated up, it's going up about one every ten seconds. With that EXTREMELY gross WAG, let's throw out some numbers:

Assuming (and this is a faulty assumption, but for lack of data) you have a constant rate of 10 seconds per degree of increase, you're looking at 10k seconds which is roughly 167 minutes, which would be two and two-thirds hours of constant running. However, I've got a strong suspicion that the rate of increase of temperature is a function of the inverse of completion. If you want the exact details, you'll have to decompile and deobfuscate the code yourself.

 

[MilConDoin]

I also tested this, but missed the perfect measuring point. My assumption is, that you get heat increase for every x amount of fuel usage.
In the beginning the temperature will rise quickly, because you use fuel quickly. Both will slow down over time. This x mentioned above is somewhere between 10k and 12k (at least while testing it with biofuel). My numbers, which are probably a bit off, seem to point at 11.6k (due to the inaccuracy).

 

[solidity]

I've recently talked to CovertJaguar on IRC to find out how the heating of the boiler happens and he even posted a pastebin of the programming behind it.
The basic gist is as following: Each game tick (20 ticks to a second), the game checks the current percent of max heat. Depending on the percentage, it adds 1-4 times the heat increment of 0.05°C to the current heat and consumes the fuel appropriate to the current temperature. Below 25% heat you get 4 increments (0.2°C), between 25 and 50% you get 3 increments (0.15°C), between 50 and 75% you get 2 increments (0.1°C) and above 75% you only get one increment (0.05°C) per tick. The change in heat is divided among the number of boiler blocks you have, so a max size boiler only gets 1/36 of the increase in heat.
I've made a lua-script based on that which will ask you for the size and fuel as well as whether it's a HP or LP boiler and provide you with the time to max heat, the total fuel consumed to heat up and the fuel required for constant use at max heat. The available fuels and fuel values are those listed on the amazing Railcraft wiki. If you find any bugs, let me know.
I'd like to thank CovertJaguar again for being so helpful and open about the inner workings of his mod

 

[Keldor]

That's exactly what I wanted to know, thank you

 

[Forecaster]

http://calculator.towerofawesome.org/