Title: Описание
Author: 1
Last saved by: www
Company: -

DESCRIPTION
INTERNAL COMBUSTION ENGINE OPERATION METHOD WITH LIQUID GAS COOLING  

The invention relates to internal combustion engines and may be used in engines for automobiles, tractors and other machines.
In the existing internal combustion engines, only a part of energy obtained from fuel combustion is used for effective work, while more than half of overall heat is lost due to heating of engine components and is carried away with combustion products. This being the case, the temperature of ignited fuel mixture reaches 2200-2500 °С, while the average temperature during operating cycle is 800-900 °С  (Kalisskiy V.S. et al. Automobile. Manual for 3^rd class drivers. "Transport" Publishing House, Moscow: 1976).
Such high temperature necessitates artificial cooling of the engine. Fluid cooling with forced circulation is usually employed for this purpose. Such a system, consisting of the cooling jacket, radiator, water pump and other components, is rather complicated and cumbersome, requires significant space under the motor hood, increasing engine mass and dimensions parameters and deteriorating aerodynamic characteristics.
The technical task is: enhancing engine efficiency, environmental safety and eliminating the fluid cooling system of the internal combustion engine, providing required heat withdrawal by alternative method.
The technical result is achieved using the method of operation of the internal combustion engine, which transforms the heat produced during combustion in the cylinders into useful work, while operational strokes based on expansion of gaseous combustion products interleave with operational strokes based on expansion of liquefied gas-coolant vapors. For example, the following substances may be used as gas-coolant: liquid nitrogen, liquid hydrogen or liquefied hydrocarbon gas; the latter two (liquid hydrogen or liquefied hydrocarbon gas) may also be used as fuel. In this case, after the cooling stroke the heated gas is fed into the cylinders again, this time as fuel.
For this purpose, it is proposed to fit-out the traditional four stroke engine (Otto engine, Diesel engine, Wankel engine), or rotary cylinder valve engine (http://rcvengines.com) with the system injecting liquefied gas-coolant (as one of the options – liquid nitrogen), which may be used simultaneously as cooling medium and as working medium performing useful work.
It is known that transition from liquid aggregative state of a substance to gaseous state entails heat absorption proportional to mass and specific heat of evaporation of the substance. Besides, heat absorption takes place during subsequent heating of cold gas vapor (for nitrogen, initial temperature equals to –196 °С) to the temperature of combustion gases remained in the cylinder (average temperature about 800 °С). Taking into consideration that gas density is much lower than liquid density (e.g., liquid nitrogen density equals to 808 kg/m^3, while gaseous nitrogen density equals to 1.25 kg/m^3 under standard conditions), excess pressure arises during evaporation of liquefied gas in small enclosed volume of the combustion chamber, which pressure is applied to the piston, performing useful work.
Operational scheme of the engine built according to this principle and fitted-out with the injection system of liquefied gas-coolant may be as follows:
1^st stroke – intake of combustible mixture;
2^nd stroke – compression of combustible mixture;
3^rd stroke – ignition of combustible mixture and operational stroke (combustion chamber is heated);
4^th stroke – release of gaseous combustion products;
5^th stroke – injection of gas-coolant into the hot combustion chamber, evaporation and operational stroke (combustion chamber is cooled);
6^th stroke – release of gas-coolant.
	Further on, the engine operation process is continuously repeated in the above mentioned sequence. Thus, the operating strokes based on expansion of gaseous combustion products (3^rd stroke, when the combustible mixture burns and generates heat), interleave with the operating strokes based mainly on expansion of liquefied gas-coolant vapors (5^th stroke, when the liquefied gas-coolant is heated by the heat generated earlier, evaporates and expands, reducing the temperature in the combustion chamber).
	Schematically, such principle of operation may be described as interleave of “hot” (from 1^st to 4^th) strokes and “cold” (from 5^th to 6^th) strokes. Regulating (perhaps, by means of electronic control system) the proportion of fuel consumption and coolant consumption, optimal thermal balance of the internal combustion engine in a broad range of loads and ambient temperatures may be achieved without usage of the traditional liquid-cooling system.
Moreover, the proposed engine option has two operational strokes per three revolutions of the crankshaft (2 strokes of 6), as compared with one operational stroke per two revolutions of the crankshaft (1 stroke of 4) in the conventional internal combustion engine, providing possibility to decrease engine weight per unit of power and saving hydrocarbon fuel, because combustion takes place only during one stroke of six.
Since this method provides fuller transformation of heat into useful work, engine efficiency is increased, while harmful emissions to the atmosphere are reduced, in case if harmless liquefied gases (e.g., nitrogen) are used for cooling.
If the fuel itself is used as gas-coolant (e.g., liquefied methane or liquefied hydrogen), then after the “cold” stroke, the heated gas is fed into the cylinders again, this time as fuel.
Depending on particular kinds of fuel and coolant, ambient temperature and other factors, engine design options are possible where two or more “cold” strokes will interleave with one “hot” stroke, or vice versa, several “hot” strokes – with one “cold” stroke.