Temperature independent fuel mixing

When fuel is mixed in a Pipe Gas Mixer, the obtained ratio can be wrong if the gases had different temperatures. By using volume pumps and some logic circuits, the correct 2:1 fuel mix can still be obtained without waiting for the temperature to equalize.

This setup measures the total fuel pressure and the ratio of oxygen in the fuel mixture, these values are then multiplied to calculate the partial oxygen pressure which is directly linked to the amount of moles of oxygen in the mixture. This also gives control over the total pressure (which is tripple the partial pressure in a 2:1 mixture) which helps with safety. Volatiles are added automatically whenever the ratio of oxygen in the fuel mix becomes too high.

If so desired, one can add a single logic processer to this setup to let the player insert the desired total pressure instead. Simply replace the B2 memory with 1 math multiplier (B2a) and 1 memory (B2b), then have B2a multiply the desired total pressure (set with B2b) with the desired oxygen ratio (B5), and let B1 compare B2a vs. A3 instead. New wires must also be added to connect all these parts together.

A problem with this setup is that it will continue to add oxygen even if the volatile storage is empty, which will ruin the fuel ratio. This can be fixed either by adding a valve (infront of the volume pumps so it doesn't blow the pipe) for manual control of the oxygen flow, or by adding circuits to shut it off. Another issue is that tweaking the memory values while the system is running can cause the fuel tank to overpressurize and burst, keep suspects with screwdrivers away from the area.

Components

• Gas pipes
• Gas storage
• Wires
• 4 Logic I/O
• 3 Logic Processor
• 2 Logic Memory
• 2 Volume pumps
• 1 Pipe Analyzer (requires electrum)

Example of how to place the circuit in a location where it's easy to blow it up

Setup

1. Connect volume pumps from O2/H2 respectively leading towards the fuel side
2. Connect the pipe analyzer on the fuel side
3. Optional: Use a Power Area Control or Transformer to isolate the logical components to their own network. This also makes it easy to shut off the system.
4. Place logical components

• A1: Reader for pipe analyzer, total pressure (in KPa)
• A2: Reader for pipe analyzer, ratioOxygen (between 0 and 1)
• A3: Math multiplier, A1*A2 (this is the partial oxygen pressure in the fuel tank)

• B1: Compare, B2 vs. A3, greater
• B2: Memory, 2000 (desired partial oxygen pressure, 3x this will be the total pressure)
• B3: Writer for Oxygen volume pump, on

• B4: Compare, A2 vs. B5, greater
• B5: Memory, 0.334 (use Labeller to set this value)
• B6: Writer for Volatiles volume pump, on

Notes

• Don't mix fuel near critical infrastructure.
• For safety, set the desired partial oxygen pressure to 2000 max, the total pressure will be tripple this value in kPa.
• If the system runs out of volatiles, the fuel mix will still be fed oxygen.
• If the system runs out of oxygen, the system will stop adding volatiles.
• Give volume pumps a 1:2 ratio on their values, this reduces errors in the fuel mix when the system is rebalancing.
• Power use 120 W on standby

Using an IC 10

If an IC 10 is used to control the fuel mixing, the formula PV=nRT can be used to manipulate the setting on the volume pumps to get a 2:1 ratio directly with maximum flow. This will speed up the fuel making considerably, but some fine tuning is still needed afterwards. The required formula can made by setting up one expression for H2 and one for O2, solve both for n, then combine the two expressions and cancel out R. We know that twice the amount of H2 is needed, that will introduce a multiple of 1/2 for the volatiles side, the expression will become:

n=PV/(RT) -> 1/2 * PV/T (volatiles) = PV/T (oxygen)

1/2 * P(H2)*V(H2)/T(H2) = P(O2)*V(O2)/T(O2)

solve for the volume ratio, since that is what the volume pumps can control, the pressure and temperature are known because they can easily be measured

V(O2)/V(H2) = P(H2)/T(H2) * T(O2)/P(O2) * 1/2

When the volume ratio is above 1, set the Oxygen volume pump to 100 L and the Volatiles volume pump to 100/ratio

When the volume ratio is below 1, set the Volatiles volume pump to 100 L and the Oxygen volume pump to 100*ratio

The volume pump can only take integers between 0 and 100, decimals will not be accepted, so rounding might be necessary. This will create a small error in the fuel mix, so some fine tuning is necessary to get a perfect 2:1 mix.