The steam engine project today…
I have spent many years working towards the completion of this project. To actually run this so called Otto cycle steam engine. Now begins the actual proof of concept demonstrations.
What has been learned? First and foremost is how flash steam actually behaves inside an engine. In theory you may run a great verity of engine types with flash steam. This includes two cycle steam engines. In an internal combustion engine there are significant heat losses. Heat lost from the radiator or generated from the compression stroke. While experimenting with flash steam, heat instantly became the primary focus. While contemplating the heat losses of the IC engine, I wondered if the same rules of loss would apply to a flash steam engine. What was found as a result of this speculation is interesting. What heat would be a lost in an internal combustion engine, becomes a performance gain with a flash steam engine. So heat generated by the compression stroke has a discrete advantage. As well as the reduced firing interval that a four cycle engine accommodates. Whereas a two stroke configuration (live steam) has a firing (admission) interval twice that of an Otto cycle engine, for the same rotations per minute of engine crank-shaft run speed. Anyone who has actually attempted to supply superheated water to an engine will realize this helps by a big amount. Since it is quite difficult to maintain this supply. The current technique that we use to get this water into the engine is a direct injection valve. So that every time the spark plug used to fire (in an Otto engine), now the direct injection valve opens for the prescribed duration. Which is usually less than a third of a power stroke from top dead centre. Since in a (very basic) live steam engine the steam is admitted “the full length of travel” of the power stroke. However, some more advanced live steam engines may in-fact feature, what is called “variable cut-off”. Four cycle (Otto) steam engines are considered intermittent in nature. “ie” they don’t admit the working medium continuously on the power stroke. Instead spark-ignition which is similar to, partial admission is utilized, and expansion is relied upon. Also, steam can expand farther after the injection duration. Differing from the chemical reaction of spark-ignition engines. It was my design goal to achieve a combustion type of reaction with flash steam. I will be the first to admit that this science is not easy. It took years of careful experimentation to know all this. Otto steam engines may be flash steam in nature, or driven by high-pressure-live-steam and alternately, compressed inert gasses such as argon.
Flash steam is tricky stuff, so do your homework. Officially flash steam is only created when water under pressure and heat, is released to a lower pressure. Which then flashes to cool itself off. Some will describe throwing water on red-hot, or hot materials as flashing steam from water. Although this sounds appropriate its really not flash steam, in the book sense. Nevertheless both of these mechanisms are used on the Otto Steam Engine described here. As the L912 Injector releases superheated water, this water turns to flash steam as it enters the engine, for one reason only, the inside of the engine has a pressure of about 125psi. The injector on the other hand is carrying between 2000psi and 700psi, and the water is around 350*f. A positive displacement pump exerts pressure on the water which is then heated by the corn burner, then this water is routed to the injector. Where it enters the engine and flashes to steam, then the flashed steam is heated further, by the already hot engine block. The engine block is heated to at least 300*f (in our case) by the corn burner as well. Depending on the metallurgy of your piston cylinder arrangement, you may reach higher temps such as 450*. If you have ever tried to manage such parameters you will know it’s a thrill a minute. Although it is doable.
This subject was brought up by a bright individual through e-mail correspondence. While exploring the viability of the Otto steam engine, heat engine. Several dynamic tests took place, these tests included driving the engine with compressed gas at a pressure of 2500psi. When the engine is run in this mode (CDFC) heat engine. There are no technical or mechanical configuration changes made. So instead of supplying superheated (critical) water (or Hp-live-steam) to the injector assembly, you can supply compressed gas. And the engine will run this way, with a high pressure source or pressure tank. The tank pressure starts at 2500psi and the engine will run down to 600psi or so. Anyone who has run two stroke engine, or air-motor this way will remark the engine gets cold. In fact with no heating activated in the
L912 Injector and none being applied to the engine block, while running a 11hp briggs engine. Ice is observed forming on the exhaust valve stem (this ice forms from relative humidity). But the heat generated by the compression stroke kept the block from getting to freezing temps simultaneously. This tends to alert me that the Otto cycle is capable of remarkable efficiencies. While running the engine this way it seemed to run forever. As a well seasoned mechanic I was stunned to see the engine run for a half hour or more on a single tank. This caught me off guard, I did not predict the engine would run so long from a single tank. Now back to the densification. A question was asked of me, which do you think is better for the engine cycle? Heat, Or densification. Lets not forget here that as the (Otto) engine runs, it is aspiring ambient air. As well as the injector, adding air to the engine (in this case) “and” the engine is taking in air through the intake stroke. All these air sources are coming in contact with the piston during a power stroke. This is what is being referred to as densification. A two stroke air motor does not do this, nor does it produce an internal source of heat from a compression stroke. I am a firm believer that you have way more to work with thermodynamically, with an Otto Steam Engine, than with a live steam engine (which may feature advanced cut-off) or air motor (which does not feature cut-off).
Applications of engine block heat
As is stated on the “basics” page it is necessary to heat the engine block for the flash steam engine to operate. In theory if the engine block is ‘cold’ you could inject a flash steam discharge into the engine and nothing will happen. Even if the flash steam discharge was coming from a super-critical source. Take this example for instance; you could contain water and heat it to 705ºf develop an internal pressure of 3204psi. Then discharge it into the engine at TDC, and the piston ‘will not’ be pushed by this discharge. However ‘as’ the engine block is heated to temperatures in excess of 212ºf a strong reaction ‘will’ occur. And the piston will move downward violently. This is the type of reaction that’s needed to run an engine. Some will speculate that as the engine is manually brought through the cycle (cranked over) it will pick up this heat from the actual flash steam discharge. Although it is true that a flash steam discharge will in fact release heat. There is a problem, the actual mass of the flash steam discharge itself is quite small in relation to the mass of the engine block assembly. So you would have to crank the engine over literally for hours to get the block to an adequate temperature for a reaction (power pulse). Since we are in fact discharging water that is hot enough to flash, this is not a cold water injection application. It has been speculated on the internet by various sources that an engine cylinder lacks sufficient surface area to evaporate cold water to steam, I agree. The engine cylinder does lack sufficient surface area to transform water to steam, ‘in most cases’. The engine that’s being worked with here, takes care of the “970 btu wall” with an actual flash steam discharge, and supplemental block-heating. The flash steam that’s formed is already steam. Its just being “superheated” by the engine cylinder and head. However there is a massive technical conundrum at work here. When the heated water is at less than the supercritical range. The Btu quantity of the water under pressure is insufficient, for a 100% transformation to steam vapor. At best under the most ideal conditions you may get 50% flash-rates. And since the sufficient btu energy needed, cannot be stored in the hot-water-under-pressure “itself”, to accommodate an 100% flash-rate. Another secondary means to add energy to the reaction MUST be employed. The common methodology to heat the engine block. Forced hot oil circulation works well for this purpose. This hot-oil is not under pressure, and may be circulated in the coolant passages surrounding the cylinder and cylinder head assembly. So the engine uses two separate heating circuits, that are both in the fire. One circuit heats the water for flash steam injection (or live steam generation) and the other heats the oil that is circulated through the engine coolant passages.
The Otto Steam Engine may run on either flash steam or compressed air or even live-steam. Providing the engine has suitable robust direct injection technology. As stated before I was unable to acquire such technology “on shelf” and Flashsteam.com single handedly developed L912 direct-injection-valves, with Variable Lift for this purpose.
Some may ask why do you call it L912 ?
We started to call the injector assembly L912 back in 1994. There were several variations of the injector you see today. The L912 was the best design overall and it became the most workable unit. And this unit easily accommodated Variable Valve Lift.
Lets dissect the name to understand its REAL origin.
L this denotes liner model (non-rotary valve)
9 this denotes 900 watts of onboard heating
12 this denotes 12 volt direct current actuation
The idea here is to continue the natural evolution of the Otto cycle engine. Which was truly the most fantastic invention in human history.
Also to demonstrate that an atmospheric balance in relation to the Carbon Cycle may be achieved using Corn Burners, for energy production needs.
The corn burners seen on this website are very different from the type used for home heating. These units are industrial grade. At the beginning of the project corn burners used for home heating were considered. However the necessity to install liquid heat exchangers caused some concern. So we started over from scratch. The first units produced were fully automated. They would have been suitable for home heating usage. But they could not accommodate the heat exchangers. The process of refinement lasted several years. And this was totally separate from the L912 design process. As you can imagine a lot of work has been necessary to get to this stage. As stated on the “corn burners” page the steam engine project (PSTG1) required a very compact unit. There was no space on the platform for a corn storage hopper. So the unit was stripped down to the bear essentials. Which is okay for that unit in particular. All the corn burners that we work with are very different and unique from what is currently available. These units do not need a fan to operate, they will induce the drought they need to operate correctly without one. However introducing compressed air at low pressure 5 to 10psi through the J-tube assembly will enable the unit to melt glass. The performance that we experience with these units is unprecedented. We just cant say enough positive things about them. When you hear the “jet engine type roar” this thing makes, then realize its doing that only with corn, well its astonishing. And the emissions that are produced are minimal. There are no noxious fumes, no smoke under all conditions, and its as cheap to run as we predicted. In fact I burn corn that the insects have gotten to all the time, little bit of mold no problem. It just works great. We heat a lot of mass with this thing and its no problem for it. This is probably the most rewarding part of the project. In the future I would like to move into plastics mold injection heating with this corn burner technology. I am looking for someone to collaborate with on such a project, preferably recycled plastics. Or even heating systems for home or large buildings.