Confused Cycle Engine

This idea builds on my earlier idea from a few years ago [link], but improves it in a few subtle ways... enough, I think, to warrant this being a separate idea.

Similar features:

* All of the valves of the engine are fully computer controlled, so we can instantly switch from a four stroke cycle to a two stroke cycle, and back, as needed.

* The engine block has no water jacket.

* The areas where hot combustion gasses are produced and exhausted are lined with high tech insulating ceramic, similar to Toyota's failed adiabatic engine. This idea will take advantage of the high rate of heat transfer that caused their engine to be no more efficient than a normal one, and put that heat to good use.

* There is a steam condenser is probably cooled by a water/antifreeze mix, which in turn is cooled by a radiator. This way, in very cold weather, we can control the rate of coolant circulation so the condenser is very-cold-but-not-freezing.

There will also be a (small) vacuum pump, to remove air from the condenser. The air that comes out of the pump will inevitably be very humid, so it would probably be a good idea to route it to the exhaust gas water recovery device.

Naturally, there's a pump to move water from the condenser, to the boiler.

* There is high pressure exhaust powered steam boiler/hot water heater. This component will be producing hot liquid, and hot steam, both of which will be used in the engine.

* Downstream of the boiler, some or all of the exhaust passes through an exhaust gas water recovery system. We only need to recover a small amount of water from the exhaust, and we don't need it to be very pure. The water needs to not have minerals or particulates, and not chemically break down when heated in the boiler.

* A computer selects from three different modes of operation, depending on the inputs of various temperature and pressure sensors.

The default mode of operation is a perfectly normal four stroke internal combustion cycle. Not only does this produce a certain quantity of mechanical power (our main product), but it also heats up the engine block, and produces hot exhaust gas. For the latter two reasons, I'll call this the heating cycle.

Note: There are many different variations of a four stroke cycle, and for the sake of discussion, I do not care which one is used. It could be an Otto cycle, a Diesel Cycle, an Atkinson Cycle, a Miller Cycle, etc.. It doesn't matter very much. I'd prefer that it take advantage of the computer controlled valves to eliminate the need for a throttle, but that's a minor detail.

It *is* important that the exhaust not damage the water boiler, but that can be avoided by using appropriate pollution controls.

When the in-cylinder temperature exceeds some threshold, the computer switches from the heating cycle, to the primary cooling cycle.

We start with the piston at top dead center, with the valves closed, and spray in a small amount of water. This water is pumped from the exhaust heated boiler, using a floating intake which ensures that it is liquid water that comes out of the injector, not steam.

The quantity of water injected is carefully chosen by the computer, to be as much as possible, but within the following additional limitations: (A) The max steam pressure won't exceed the engine's tolerances. (B) The steam pressure at the end of the first (expansion) stroke doesn't exceed the pressure in the steam condenser. (C) The average torque over the two stroke cycle must not be significantly more than the average torque of the most recent four stroke cycle.

The water strikes the piston face and cylinder walls, and is heated by them, changing from liquid to steam. Since this phase chance happens in a confined space, it produces high pressure. As the piston descends, the expanding steam pushes on it, producing torque.

On the second stroke of the cycle, the low pressure steam valve opens to allow steam out of the cylinder, into the steam exhaust manifold, which leads to the condenser.

The computer keeps the engine in the primary cooling cycle until the engine's insides are cool enough to switch back to the heating cycle.

When the steam pressure in the boiler exceeds some threshold, the computer switches to the secondary cooling cycle. This is a simple two stroke steam expansion cycle. It cools the engine a bit, but not as much as the primary cooling cycle.

In the first stroke, the high pressure steam valve opens, steam comes in, then shortly afterward the valve closes. The piston continues to descend, and the steam expands against it, producing mechanical energy.

The quantity of steam admitted is selected by the computer to have the same criteria as was used for quantity of water to inject, in the primary cooling cycle.

The second stroke of the cycle is the same as the second stroke of the primary cooling cycle.

The computer keeps the engine in this cycle until the steam pressure in the boiler drops below some threshold, after which it switches back to the heating cycle.

The reason why the idea is named as it is, is because the the engine will switch between the three modes of operation in a pattern that a human probably wouldn't predict. Also, I fully expect that the exhaust noise would be... well, odd.