Combustion Engines Haven't Been Updated in 100 Years
Over 120 years ago, the thermodynamic cycles for Otto (gasoline) and Diesel cycles for internal combustion engines were developed — and the piston engine design hasn’t changed much since the days of Henry Ford. LiquidPiston has designed a totally new type of rotary internal combustion engine technology. The design is new. The thermodynamic cycle is new; the approach is rooted in physics and optimization. The engine is up to 2x more efficient than comparable powered gasoline engines in production today, and up to 10x smaller and lighter than comparable Diesel engines.
Much like a piston engine can be configured to run on different fuels, the LiquidPiston engine can do the same. We have demonstrated the engine on gasoline, Diesel, kerosene, and JP8 fuels. Our most advanced engine prototype, the 70cc Spark-Ignited XMv3 engine, has successfully run multiple types of fuel in a single configuration, including gasoline and kerosene. Our 300cc X4 concept is intended to run Compression Ignition on Diesel.
Piston Engine vs. LiquidPiston
Today’s gasoline engines, in a typical automotive drive cycle, only convert about 20% of the available energy in the fuel into useful mechanical work, and 80% of the energy is then wasted as heat in the exhaust, or out the radiator.
Our approach fundamentally changes the thermodynamic cycle of the engine to make a much more efficient engine. As a result, our engine has the potential to be up to two times more efficient than a gasoline engine, while also being incredibly power dense – about 10 times smaller and lighter than any other diesel engine out there; it is also quieter, and has near zero vibration. In addition, the X Engine is incredibly simple – it has just two primary moving parts, and yet it achieves three combustion events per rotor revolution, resulting in tremendous power density.
Video: Old School Engine Inefficiency
The traditional combustion process is far from ideal. Today’s engines rely on injecting, mixing, and burning the fuel while the piston is near “Top Dead Center”, but it takes a long time. By the time the engine is actually burning the fuel, the piston is already expanding and the pressures are dropping due to expansion which fight the combustion, so the engine is not efficiently converting the heat from combustion into mechanical work.
Video: Liquid Piston Efficiency
The ‘X’ rotary engine allows for a longer period to burn all of the fuel at a nearly constant combustion chamber volume. The arc of the rotor matches the arc of the housing, which means that the rotor can continue turning at high speed while the combustion chamber volume remains approximately constant for a longer period. This gives the engine more time to burn the fuel resulting in a much more complete combustion process before it starts expanding the gases. Constant Volume combustion has been shown, thermodynamically, to improve efficiency by 50% over a Diesel engine.
More efficient than other gas engines
Smaller and lighter than comparable diesel engines
Combustion events per rotor revolution
"Today, a 30kw diesel generator weighs 2750 pounds. Imagine the impact if we can reduce that to less than 200 pounds! Such an ultra-portable generator can be used in new applications, for example to charge the battery of an Electric Vehicle (REV), or enable hybrid electric drones."
LiquidPiston vs. Wankel Rotary Engine
Old-Style Wankel Rotary Engine
- Otto cycle – gasoline only
- Efficiency less than 25%
- Sealing/lubrication issues
+ High power density
LPI X - Engine
+ HEHC cycle – diesel/gasoline/multi-fuel
+ Efficiency greater than 40% (depending on size)
+ Sealing/lubrication solved
+ High power density
See How It Works
The X engine is simple, having only 2 moving parts – a rotor and a shaft – making the engine incredible compact, up to 10x smaller and lighter than today’s comparable power diesel engine. Yet it executes the optimized High Efficiency Hybrid Cycle, potentially doubling the fuel economy of the engine, while achieving 3 combustion events per revolution. The low part count and reduced raw material could make the engine significantly cheaper when volume production is reached.
LiquidPiston in Action
In June of 2016, the X-mini engine has been successfully installed into a vehicle demonstrator (e.g. a "Go-Kart"), marking a significant milestone in development. This milestone is the first time the engine was run outside the lab, and shows the engine powering something tangible that users can feel. Significant development was required to move the engine from the lab and into this application, especially in cooling the engine so it does not overheat, developing the controls and mapping the engine across its operating band, etc.
Immediate Use Cases
Over the past four years, LiquidPiston has developed the XMv3 "X-Mini" 70cc Spark Ignited engine, which is the Company’s most advanced demonstrator to date. An engine of this size could power everyday items like handheld lawn equipment, including chainsaws or brush cutters, small generators, or small vehicles including mopeds, go-karts, etc. (as shown by our go-kart video above). This engine is demonstrated in and out of the lab, and is already showing excellent power density, low-vibration, good fuel economy, and ability to run on multiple fuels including gasoline or JP-8.
This is just the beginning; we're also developing a 30kW X4 Diesel rotary engine. The objective of the X4 program, for which we have received DoD development funding, is to make a 30kW engine that will fit in a 10x8x8" box, weigh just 30 pounds, and operate at 45% brake thermal efficiency - better efficiency than a heavy duty truck, from an engine the size of a shoebox!
Left: Current US Military 30 kW generator. Right: Proposed X-4 engine-based generator.
In addition to ultra compact and efficient generators, and power for things like drones, companies that produce electric vehicles (including ground and air vehicles) may also be interested to use our small ultra efficient engine as a range extender to charge their batteries and dramatically extend range, or enable EVs that use small, cheap, lightweight battery packs, but still offer the consumer the range and ability to rapidly refuel their vehicles that drivers expect – all at a potentially lower CO2 footprint as compared to plugging your EV into the U.S. Power Grid!
Ultimately, we see our engine platform replacing any engine in use today, addressing a $460 Billion market opportunity. Before addressing the larger automotive and trucking markets, our strategy is to identify initial niche applications, where customers have an immediate and painful need for higher power to weight Diesel engines, and more fuel efficient engines. To that end, the company already has a lot of traction with the military, which could be a great beachhead customer. They need improved engines for vehicles, generators, drones, power for other land, sea, and air vehicles, robotics systems, etc.
What We've Accomplished Since Our Last Raise
Since the close of our last raise, we began a multi-phase program funded by the Department of Defense. We exceeded all the reach goals set out by the phase one, and were awarded a $2.5M follow-on contract for phase two, which will run through October 2018, to prove out the engine's power and efficiency. This program is for our 30kW, 40hp X4 rotary engine for diesel and jet-fueled engines, which the military relies on. If we successfully complete phase two, the next step is to transition the technology to large-scale production and sales, test the X4 in an application, then ramp up production.
Our X-mini engine, seen in the go-karts, is in the transition phase, nearly ready to be packaged into a generator application We're halfway through a two-year $3 million contract from the Army's Rapid Innovation Fund which runs from March 2017 to March 2019 for the X-Mini engine. Field tests will start in March 2019.
New Thermodynamic Cycle
Dr. Nikolay Shkolnik and Dr. Alexander Shkolnik invented the innovative HEHC thermodynamic cycle and initial engine designs that embody the cycle.
Grant from Army
Received small business innovation research (SBIR) grant from Army as well as our first venture funding.
New Engine Architecture
Invented and designed a new engine architecture, model "X," that embodies the HEHC cycle.
Most advanced prototype to date, the X-mini demonstrates good power density, fuel efficiency, low-vibration, and was installed into a vehicle (go-kart) demonstrator.
Ongoing Durability and Increased Efficiency
We were able to run our most recent engine for ~15 hours without over heating. Our next goal is 50 hours, which is the basic requirement for EPA certification as a handheld engine. Our ultimate goal is to have it run for hundreds or thousands of hours.
Letter from Alexander Shkolnik (CEO) to Potential Investors
July 5, 2018
We are a father and son team: Nick, a physicist and accomplished inventor, and Alec, an MIT-trained computer scientist. We set out 14 years ago to fundamentally improve combustion engines in order to make an impact that will last for generations to come. The reality of today’s engines is that ~80% of the energy in fuel is wasted as unutilized heat. That’s unnecessary, and results in far too much CO2, CO, NOx and other emissions that negatively impact our environment. There have been many incremental improvements to engines over the last century – but few breakthroughs have had significant impact.
Our approach is rooted in physics. We started with defining a new thermodynamic cycle, and then experimented with different engine architectures to embody this cycle using available tools and materials. After more than 12 years, and $20M invested in development, our fourth generation engine architecture, the “X” Engine, is ready for launch. The implications are profound. In an era where we are emitting too much CO2 and other pollutants, and where the US imports 1/3 of our fuel from global sources, our technology can have ramifications on the climate, on national security, as well as on consumer’s pocketbooks, as we can save $ Billions for consumers at the pump.
We all recognize that trucks and automobiles are a dominant consumer of fuel, and the past several years have seen a focus on “Zero Emission” vehicles, e.g. electric vehicles (EVs). Unfortunately, the reality is that the electricity comes mainly from burning oil, gas and coal – with significant CO2 footprints. EVs have additional issues – batteries are expensive and contain toxic materials; motors use rare earth magnets; etc. Ironically, we do believe that electric cars will be the future – just not exactly how Tesla’s Elon Musk envisions it. We see our technology complementing, e.g. “range-extending”, an EV utilizing a small, lightweight, inexpensive battery pack. Such an approach can lower the CO2 footprint of the vehicle compared to charging a “pure” electric vehicle on the U.S. power grid. Drivers would retain the range they are accustomed to and the ability to refuel rapidly, at any fuel station, using existing infrastructure, while 90% of one’s daily driving could be accomplished in a single battery charge - a winning solution for everyone.
The irony does not escape us – we are proponents of electric vehicles who have started an internal combustion engine company. We believe that the global economy will be dependent on fossil fuels for many decades and that engines used in transportation applications, if optimized, will complement electric power systems for optimal efficiency, reliability and environmental sustainability. With a range extended system, we can take advantage of the benefits of both types of power generation.
Unfortunately, the design-in time to adopt a new powertrain technology into the automobile industry can take up to 20 years. This is not an appropriate time scale for a startup. For this reason, we have developed a phased technology roadmap that starts with engines that can serve the military. Our military forces have an immediate need for lighter, smaller, more efficient Diesel (heavy fuel) engines. Our initial product lines will include a 2-3kW (3-5 HP) engine/generator, and a 30kW (40 HP) engine. Both of these products will find commercial applications beyond the military – in handheld power products, small vehicles, generators, etc. We currently have the X-Mini engine powering a go-kart as a vehicle demonstrator. Our strategy is to prove the engine in these “niche” applications, which, by the way, have Total Available Markets measured in the tens of billions of dollars, before launching a product for the automotive market. Thus, we start with very big markets, and end with huge markets.
The combustion engine market is ripe for a disruption. Your investment can help make it happen. We welcome your support to take this revolutionary new engine technology from prototype to productization and use in real world applications.
Thank you from our whole team!
~ Alexander & Nikolay