Safe combustion

Hydrogen in the tank is energy. Hydrogen in the room air is a bomb waiting for a spark. A fire protection chip recognises both: the fire when it burns, and the danger before it burns.

Reading Combustion#

Combustion exists on many devices: on the gas sensor for the room air, on pipe analyzers, tanks, furnaces, generators. The value is 1 while the atmosphere there is burning, otherwise 0.

lbn fire SENSOR HASH("Lager") Combustion Average

A gas sensor in the fuel store is thus a smoke detector that does not wait for smoke.

Ignition danger#

Fire needs three things: fuel, oxidiser and ignition. The chip can measure the first two. If there is hydrogen or methane in the air and enough oxygen, a spark is enough – from the arc furnace, the furnace, a tool. From 573.15 K hydrogen and methane even ignite all by themselves according to the gas data. Nitrous oxide (N₂O) and ozone are oxidisers too.

add tmp tmp tmp2
sgt danger tmp FUEL
lbn tmp SENSOR HASH("Lager") RatioOxygen Average
sgt tmp tmp OXYGEN
and danger danger tmp

Hydrogen without oxygen, for example in a pure nitrogen atmosphere, does not burn. Hence the and.

Emergency shutdown#

On fire or ignition danger the chip closes the fuel valves and stops the pumps. No supply, no bigger fire. With fire the alarm comes on top: Sound.FireFireFire on the klaxon.

The fire alarm latches. When the fire is out because the oxygen is used up, the cause is not gone yet. Only when there is no more fire and someone acknowledges does the alarm go off. The ignition danger, on the other hand, does not latch: it only depends on the readings and disappears with the leak.