LiquidPiston
LiquidPiston, Inc (LP) develops compact, quiet, high-efficiency, low-vibration,multi-fuel capable combustion engines that are scalable from 1HP to over 1000 HP. LiquidPiston’s X Engine is a non-Wankel rotary embodiment of the company’s innovative High Efficiency Hybrid Cycle (HEHC).
Facilities
Located in Bloomfield, CT, in a 6000 sq. foot space, LiquidPiston maintains state-of-the-art laboratory facilities dedicated to developing and testing engines and supporting components. LiquidPiston has workstation computers with software for engineering and modeling engine systems, and has built two fully equipped dynamometer/test cells and laboratory test setups with instrumentation. LiquidPiston also has a machine shop with CNC machining and assembly capabilities.
While working for LquidPiston I worked on a myriad array of projects. These included research, CAD, and fabrication. My work was primarily around the development of the x-mini as small 2 chamber 1 horsepower rotary motor. My work involved fuel delivery packages, motor redesigns, and benchmarking.
The X Engine’s few moving parts consist of a rotor (the primary work-producing component) and an eccentric shaft. Except for ancillary parts such as injectors, fuel pumps, and oil pumps, there are no other moving parts, making the X Engine extremely simple and elegant.
LiquidPiston’s X Engine architecture geometry allows for standard materials and 2-D manufacturing to be used, greatly decreasing the design, build and testing cycle.
While it is a rotary engine, LiquidPiston’s X Engine is NOT a Wankel engine. It has a fundamentally different thermodynamic cycle, architecture and operation.
The High Efficiency Hybrid Cycle (HEHC) is a patented thermodynamic cycle developed by LiquidPiston that combines the individual advantages of the Diesel, Otto and Atkinson thermodynamic cycles. The cycle is characterized as follows:
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Air is compressed to a high compression ratio, as in the Diesel cycle.
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Fuel is added and compression ignition occurs, also similar to Diesel. Unlike a Diesel, the volume is held constant for most of the fuel injection, mixing and combustion process. Thus, the heat-addition process can be modeled as isochoric (constant volume), similar to Otto cycle models, resulting in higher temperatures, pressures and efficiencies than both the Otto and Diesel cycles.
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Combustion products are over-expanded to atmospheric pressure using a larger expansion volume than compression volume, as in the Atkinson Cycle.
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Cycle-skipping power modulation allows high efficiencies at low power settings while simultaneously cooling the engine’s walls internally and providing partial heat recovery. The overexpansion significantly increases the heat recovery and engine cooling.
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Water may be injected to internally cool the engine. Some of this cooling energy is recuperated, as the water turns to steam, increasing the chamber pressure.
