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US 2011/0023814 A1Published application
Isochoric Heat Addition Engines and Methods
AssigneeLiquidPiston, Inc.
InventorsNikolay Shkolnik, Alexander C. Shkolnik, Stephen L. Nabours, Ryan D. Nelms
Life of this patent
Estimating the term…
Abstract
Engines and methods execute a high efficiency hybrid cycle, which is implemented in a volume within an engine. The cycle includes isochoric heat addition and over-expansion of the volume within the engine, wherein the volume is reduced in a compression portion of the cycle from a first quantity to a second quantity, the volume is held substantially constant at the second quantity during a heat addition portion of the cycle, and the volume is increased in an expansion portion of the cycle to a third quantity, the third quantity being larger than the first quantity.
Claims18
A rotary engine comprising:
- a. a housing having an intake port and an exhaust port;
- b. a rotor rotatably mounted in the housing;
- and
- c. two gates, each gate movably mounted with respect to the housing, so that each gate is engaged at least periodically with the rotor, wherein during engagement of at least one of the two gates with the rotor a volume is maintained between a surface of the at least one gate, the rotor, and the housing, the volume exhibiting a cycle during rotation of the rotor wherein the volume is reduced in a compression portion of the cycle from a first quantity to a second quantity, the volume is held substantially constant at the second quantity during a heat addition portion of the cycle, and the volume is increased in an expansion portion of the cycle to a third quantity, the third quantity being larger than the first quantity.
1 more element
A rotary engine comprising:
- a. a housing having at least one intake port and at least one exhaust port;
- b. a plurality of rotors rotatably mounted in the housing, each rotor coupled to one of the at least one intake port or to one of the at least one exhaust port;
- c. a plurality of gates, each gate associated with, and in contact with, one of the rotors;
- d. at least one combustion chamber, each of the at least one combustion chamber being in communication with each rotor of a pair of the rotors, a first rotor of the pair of rotors being coupled to one of the at least one intake port and a second rotor of the pair of rotors being coupled to one of the at least one exhaust port, the first and second rotors moving synchronously, wherein (i) the first rotor and its gate define in relation to the housing a compression volume exhibiting a compression portion of an engine cycle during rotation of the first rotor, by which a compressed volume of air is periodically coupled to the first rotor's corresponding combustion chamber and (ii) the second rotor and its gate define in relation to the housing an expansion volume exhibiting an expansion portion of the engine cycle during rotation of the second rotor, by which a combusted mixture in the first rotor's combustion chamber is periodically coupled to the expansion volume;
- wherein the compression volume is reduced in the compression portion of the cycle from a first quantity to a second quantity, a volume in which combustion occurs is held substantially constant at the second quantity during a heat addition portion of the cycle, and the expansion volume is increased in the expansion portion of the cycle to a third quantity, the third quantity being larger than the first quantity.
2 more elements
A rotary engine comprising:
- a. a housing having an intake port and an exhaust port and an interior surface having a first arcuate segment characterized by a constant radius of curvature and a second arcuate segment characterized by a shape different from that of the first segment
- b. a rotor rotatably mounted concentrically within the first segment of the housing, and disposed concentrically around a C-cam having a constant radius cylindrical surface except where it has a recess;
- c. at least one compression vane movably mounted in the rotor for contacting the C-cam and defining a compression volume with the rotor, the C-cam, and the housing;
- d. at least one expansion vane movably mounted in the rotor for contacting the interior surface of the housing and defining an expansion volume with the rotor and the housing;
- e. a combustion chamber, disposed in the rotor, associated with the at least one compression vane and the at least one expansion vane, wherein (i) the compression volume exhibits a compression cycle during rotation of rotor, by which a compressed volume of a working medium is periodically coupled to the combustion chamber and (ii) the expansion volume exhibits an expansion cycle during rotation of the rotor, by which combustion products in the combustion chamber are periodically coupled to the expansion volume.
2 more elements
An internal combustion engine comprising:
- a housing having an intake port and an exhaust port;
- a low pressure chamber and a high pressure chamber disposed in the housing, the low pressure chamber being larger than the high pressure chamber, each chamber having an epitrochoid-shaped interior in which is disposed a three-apex rotor, rotationally mounted to move eccentrically within the corresponding chamber, to establish three cavities, which over an engine cycle, handle the functions of intake, compression, intermediate, and expansion, three of such functions being operative at any given time in each chamber;
- wherein (i) the cavity handling compression in the low pressure chamber is coupled to the cavity handling intake in the high pressure chamber;
- (ii) the cavity handling expansion in the high pressure chamber is coupled to the cavity handling expansion in the low pressure chamber;
- and (iii) the cavity in the high pressure chamber handling the intermediate function handles heat addition so as to produce combustion therein.
2 more elements
A system for sealing a rotor of an internal combustion engine in relation to a housing, the rotor having an edge and a face, the system comprising:
- a. a groove formed in the face of the rotor, proximate to the edge and having a radially inward wall and a radially outward wall, the groove having a bevel located in the radially outward wall;
- and
- b. a sealing strip disposed in the grove and having, in contact with the groove, a conformal surface;
- wherein the strip is engaged in frictional contact against the housing, the housing presenting to the sealing strip a substantially flat surface, the friction tending to cause the strip to rotate slightly with respect to the rotor and to move slightly axially in a direction out of the groove, so as to reduce any gap between the strip and the housing and so as to increase sealing between the rotor and the housing.
1 more element
An improved rotary internal combustion engine of the homogenous charge compression ignition type, causing combustion of a fuel-air mixture when a state of the mixture is transformed from subcritical to critical, wherein the improvement comprises:
- a catalytic surface carried on a mechanical substrate, the surface being normally concealed from the mixture;
- and
- a trigger for initiating combustion by causing the catalytic surface to be exposed to the mixture when the mixture is placed under minimum volume conditions.
A method of operating an HEHC engine in a manner permitting adjustment of power output, the method comprising:
- in the heat addition portion of the cycle, adding fuel to the volume and causing combustion of the fuel, the amount of fuel added, when fuel is added, being substantially constant over all cycles, so as to produce maximum power over each cycle when fuel is added;
- and
- controlling addition of fuel to occur only over a sufficient number of cycles per unit of time in order to produce a desired power output of the engine, and, for each cycle wherein addition of fuel is withheld, supplying heat during the heat addition portion of the cycle by heat transfer from at least one of (i) walls of the engine directly and (ii) a heat exchanger.
Dependencies are inferred from the claim text.