Internal-combustion engines – Rotary – With transfer means intermediate single compression volume...
Reexamination Certificate
2000-10-06
2002-12-03
Koczo, Michael (Department: 3746)
Internal-combustion engines
Rotary
With transfer means intermediate single compression volume...
C123S238000, C418S083000, C418S091000, C418S179000
Reexamination Certificate
active
06488004
ABSTRACT:
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to internal combustion engines and, more particularly, to an internal combustion engine that is significantly more efficient than those known heretofore.
Internal combustion piston engines have been familiar and ubiquitous since the days of Otto and Diesel. These engines suffer from several widely recognized deficiencies. One is that their thermal efficiencies are far less than their theoretical efficiencies according to the second law of thermodynamics. Up to 30% of the heat released by fuel combustion is absorbed by the engine cooling systems. Another 30% is devoted to engine operation, including compressing air or an air-fuel mixture in the cylinders of these engines. From 5% to 20% of the available energy may be wasted because of incomplete combustion of hydrocarbon fuels. The net result is that these engines generally have overall efficiencies between 32% and 42%.
Another deficiency of these engines is that their exhausts tend to contain toxic substances: carbon particles and carcinogenic hydrocarbons because of incomplete combustion, and nitrogen oxides formed at the high (1800° C. to 2000° C.) combustion temperatures that characterize these engines. A third is that they provide power by transforming the reciprocating motion of their pistons to the rotary motion of their crankshafts. When the fuel-air mixture in a cylinder of an internal combustion engine explodes, the piston is at or near top dead center. At this position, the moment arm, across which the rod connecting the piston to the crankshaft transfers force to the crankshaft, is close to zero. Therefore, the piston exerts minimal torque on the crankshaft. As the piston moves down from top dead center, the moment arm through which the piston transfers force increases, but in the meantime the combustion gases expand somewhat, losing some of their propulsive force, so that the maximum torque exerted on the crankshaft is less than the maximum torque that could be exerted if the force of the piston could always be transferred to the crankshaft at maximum moment arm. Several attempts have been made to address some of these deficiencies.
Ferrenberg et al. (U.S. Pat. No. 4,928,658) use a heat exchanger to preheat the input fuel and air of an internal combustion engine with some of the heat of the exhaust gases. Loth et al. (U.S. Pat. No. 5,239,959) ignite the fuel-air mixture in a separate combustion chamber before introducing the burning mixture to the cylinder, in order to attain more complete combustion and inhibit the formation of nitrogen oxides.
Forster (U.S. Pat. No. 5,002,481) burns a mixture of fuel, air and steam. This mixture burns at a relatively low temperature of about 1400° C., and nitrogen oxides are not formed. Gunnerman (U.S. Pat. No. 5,156,114 and in RE35,257) burns a mixture of hydrocarbon fuel and water, but requires a hydrogen-forming catalyst to achieve the same power with his mixture as with ordinary gasoline. Each of these prior art patents addresses only one of the defects of reciprocating internal combustion engines. None addresses the problem in its totality. U.S. Pat. No. 5,797,366, which is incorporated by reference for all purposes as if fully set forth herein, and co-pending U.S. patent application Ser. No. 09/069,545, describe an engine that further addresses the outstanding deficiencies of existing internal combustion engines. Firstly, in this engine, the axis of rotation of the power shaft of the engine is perpendicular to the plane of motion of the piston. The piston is connected to the power shaft of the engine, and the force of the piston always is applied to the power shaft at a constant moment arm perpendicular to that axis of rotation, so that maximum torque is imposed on the power shaft.
Secondly, in this engine, high pressure steam is extracted from the cooling system and returned to the combustion chambers, thus preventing severe heat loses and increasing thermal efficiency. Thirdly, ecologically it is a desirable engine in which a mixture of fuel, air and steam is burned in one or more combustion chambers, each combustion chamber being defined by a toroidal combustion chamber housing, a piston and a valve. The mixture is burned at a temperature of about 1800° C. which is by about 200° C. lower than the combustion temperature in existing internal combustion engines, thereby minimizing the formation of nitrogen oxides and reducing the warming up of the globe.
Yet, the toroidal engine of U.S. Pat. No. 5,797,366 and co-pending U.S. patent application Ser. No. 09/069,545 has a principle drawback; the volume of the combustion chamber increases as the burning mixture pushes the piston away from the valve. This increase in volume, before the mixture is entirely burned, tends to decrease the thermodynamic efficiency of this engine. The engine described in PCT Application US99/19315, which is incorporated by reference for all purposes as if fully set forth herein, and in U.S. application Ser. Nos. 09/146,362 and 09/250,239 is free from this drawback because the combustion stage there, takes place at a constant volume.
Thus, the thermodynamic efficiency of the combustion stage of the engine described in PCT application US99/19315 and in U.S. application Ser. Nos. 09/146,362 and 09/250,239 is superior to the efficiency of the corresponding engine which is described in U.S. Pat. No. 5,797,366 and co-pending U.S. patent application Ser. No 09/069,545, and therefore it represents a very efficient engine from the mechanical, and thermodynamical standpoints.
In order to construct and to operate this engine, its basic mechanical design has to be accompanied by a thermal design which will address the main point of its cooling and the prevention of heat loses during its operation.
Yet, even this engine has some thermal inefficiency which is related to its heat loses. It is known that rotary internal combustion engines have unique dynamic thermal control problems which are partly described in U.S. Pat. No. 3,964,445 to Ernest, et al. Summing up briefly: The inner surface of the rotor housing is subjected to higher temperatures and to much greater temperature extremes as compared to the inner surfaces of the cylinders of the reciprocating engines.
The uneven temperature distribution along the inside of the toroidal chamber and the need to dissipate large quantities of heat, dictate the use of a good heat conductor, consisting of aluminum alloy, as the housing material, even so, the Wankel engines which have a housing made of aluminum, and which are the only type of rotary engine which have achieved commercial success, can be cooled efficiently only because the large surface-to-volume ratio of their combustion and expansion chambers.
It appears that regulating and stabilizing the temperature of a rotary engine during operation and minimizing heat loses to surrounding are apparently two contradicting objects which their simultaneous fulfillment is yet an unsolved problem.
As a result most rotary internal combustion engines did not live to their expectations, and it is impossible to utilize their basic advantages.
SUMMARY OF THE INVENTION
I have discovered that: in the engine of PCT Application US99/19315, raising the temperature of the inner surface of the toroidal chamber in general, and of tile inner surface of the combustion chamber in particular, to 650° C.-700° C., optimizes the thermal efficiency of the engine, provided that the engine can be cooled effectively, without wasting the heat absorbed by the coolant. This leads to an improvement of the engine.
The present invention is the thermal design of a toroidal internal combustion engine, aimed to enable this temperature range of the inner walls of the combustion chamber, which includes the selection of the appropriate materials for its construction, and method of its stable operation.
According to the present invention there is provided an engine including: (a) at least one housing; (b) a rotor, rotating within the at least one housing, and (c), a mechanism for supplying fuel
Friedman Mark M.
Koczo Michael
Medis EL Ltd.
LandOfFree
Toroidal internal combustion engine and method for its... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Toroidal internal combustion engine and method for its..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Toroidal internal combustion engine and method for its... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2958212