Codex Energy Gas Engine

Gas Engine

The Gas Engine is a piston engine with a generator: a compact power plant that burns fuel gas and follows the demand. It starts in 2 seconds, runs up and down with what your machines take and wastes no fuel when nobody needs energy. Its exhaust heat and its cooling water can be used too. It is a tier II plant.

How it works

1. Fuel gas comes in: syngas, hydrogen or natural gas.
2. The cylinders burn it. Each Engine Cylinder delivers up to 80 E/t; the engine turns 0.32 of the fuel's heat into energy.
3. The load follows a setpoint or, by default, the fill of the engine's own buffer.
4. Waste heat: 0.6 of the heat that does not become energy leaves as exhaust heat through Heat Ports; the rest heats the engine block.
5. Cooling water carries the block's heat away and leaves as Hot Coolant.
6. Energy goes out through the Energy Output Ports.

Building

Shown size: 3 wide, 2 high, 6 deep (adjustable: Cylinders 1–8).

One example of many: within the rules on this page, size and arrangement are up to you; the Build Projector shows the plan in every allowed size.

	Key	Block	Count
	A	Engine Cylinder	4
	F	Energy Output Port	1
	B	Engine Generator	1
	D	Fluid Input Port	1
	E	Fluid Output Port	1
	C	Gas Input Port	1
	G	Heat Port	1
	0	Gas Engine Controller	1

Step by step

Each picture adds one layer, from the bottom up; the newest layer is bright. The controller wall faces you on the left.

Step 1: Layer 1

Parts in this step: Engine Cylinder (A) ×4, Energy Output Port (F) ×1, Engine Generator (B) ×1, Fluid Input Port (D) ×1, Gas Engine Controller (0) ×1, Gas Input Port (C) ×1, Heat Port (G) ×1

Step 2: Layer 2

Parts in this step: Fluid Output Port (E) ×1

Rules

• Line: the controller faces out; behind it lie 1 to 8 Engine Cylinders in a straight line, closed by exactly one Engine Generator.
• Controller: place it while you look along the line: its front faces you, the cylinders follow behind it.
• Ports: they join the engine when they touch a cylinder or the generator, on any side, also above or below. Each port works on the side facing away from the part it touches. Allowed: Gas Input Port (fuel gas and oxygen), Fluid Input Port (cooling water), Fluid Output Port (hot coolant), Energy Output Port and Heat Port (exhaust heat). Other ports next to the line are simply ignored.
• No casing: the engine is just the line; it can stand in the open.

Fuel

Gas	Heat per mB	Fuel per cylinder at full load (mB/t, about)
Natural gas	8 HU	31
Hydrogen	6 HU	42, or 51 when knocking
Syngas	4 HU	63

• Fuel per tick = power ÷ 0.32 ÷ heat per mB, times the server's volt.fuelConsumptionMultiplier (default 1.0, allowed 0.01–100.0).
• Hydrogen knocks above 0.75 of full load: the efficiency drops to 0.26 and more heat goes into the block.
• Oxyfuel: with oxygen in its oxygen tank the engine burns 2 mB of gas per mB of oxygen, and each mB of gas gives 1.25 times its heat, so it needs less gas. Without enough oxygen it runs on air.
• The tank holds one gas at a time. Compressed gas is not accepted.
• With a full buffer the engine idles down instead of burning fuel for nothing.

Load control

• I/O: starts or stops the engine. A new engine is off: press I/O first. After starting, it cranks for 40 ticks ("Cranking") before it gives energy.
• Mode (>): "Follow demand (own buffer)" or "Fixed setpoint".
• Follow demand (default): full load while the buffer is at most 20 % full, no load from 80 % on, in between evenly less. The engine therefore makes about as much as the cables take out.
• Fixed setpoint: the - and + buttons set the load in steps of 60 E/t, from 0 up to the generator limit (cylinders × 80 E/t).
• Ramp: the load moves towards its target at most by full load / 40 per tick, so from standstill to full load in 2 seconds.
• The server's volt.generatorOutputMultiplier (default 1.0, allowed 0.01–100.0) scales the output.

Cooling and overheating

• The engine block holds 400 HU per degree and cylinder and starts at 20 °C.
• Thermostat: from 80 °C cooling water flows, up to 12 mB/t per cylinder. Each mB carries 10 HU away and leaves as one mB of Hot Coolant. With water, the block stays around 80 °C even at full load.
• Derating: above 110 °C the load falls, down to 40 % at 130 °C, and a warning sign appears over the engine.
• Overheat stop: at 130 °C the engine stops ("Overheated, stopped"). It can only be started again once the block has cooled below 70 °C.
• Hot coolant must leave: if the hot coolant tank is full, no more water flows, and the engine overheats. Pipe the hot coolant to a Heat Exchanger, which makes steam from it and gives the water back.

Warning

No water, no long run Without cooling water a four-cylinder engine at full load reaches the derating temperature in less than half a minute and then stops. Always connect the Fluid Input Port before the first start.

Exhaust heat

0.6 of the waste heat (on natural gas at full load about a hundred HU per tick and cylinder) leaves through the Heat Ports to the consumer on their outer side: the Heat Port of an Industrial Boiler, a Stirling Generator, a Foundry. Heat nobody takes in the tick goes up the stack. More: Process heat.

The screen

• Status: "Off", "Cranking", "Running", "No fuel", "Overheated, stopped" or the structure error; Mode: "Follow demand (own buffer)" or "Fixed setpoint".
• Bars for Energy, Fuel, Water and Hot coolant.
• Output (made in the last tick), Load target, Setpoint, Generator limit, Fuel flow, Exhaust heat (HU/t), Engine block (its temperature), Efficiency (the engine's efficiency), Cylinders and Oxygen (oxyfuel +25 %).
• Buttons: I/O, > for the mode, - and + for the setpoint.

Error messages

Message	What to do
Missing parts: Engine Cylinder ×1	Put at least one cylinder directly behind the controller.
The line behind the controller must end with Engine Generator (near …)	Close the line of cylinders with one Engine Generator.
Structure too large or not closed near …	More than 8 cylinders; shorten the line.
Part of the structure is not loaded (…)	Load the chunks of the whole engine.

Building the parts

	Redstone Dust
			→ Gas Engine Controller

	Blast Furnace		→ Engine Cylinder

			→ Engine Generator

When you break the controller, fuel, water, hot coolant, energy and the block's temperature are lost.

In the world

The pistons of the cylinders move with the crank speed, faster at higher load. The cylinders glow when the block gets hot (from about 90 °C up to the stop temperature). Exhaust smoke rises while it runs, more when no Heat Port takes the exhaust heat.

Tip

Gas engine or gas turbine? The engine is small, starts fast and follows the load by itself, but its output ends at 8 × 80 E/t. The Gas Turbine is bigger and needs to be sized, but makes more energy per mB and much more in total. Use engines for changing loads and as backup next to steady plants.