Improving fuel efficiency of the engine.
The modern scales of the production of the piston engines of the internal combustion have resulted in their significant impact on an environment. The emission from engines of internal combustion essentially increase the concentration of the chemical substances in the air, water, soil and become dangerous to the human life. The problem now has no solution and at the same time is characterized by the steady tendency of the increase.
One of the basic ways to decrease the harmful emission of by-product gases is to improve fuel efficiency of engines. The size of harmful emissions is determined by the perfection of a design of the internal combustion engine.
It is necessary to note, that the huge work on the perfection of the engines now is being done and significant results in the decrease of emissions in an environment are being achieved.
At the same time, the tendency of the increasing impact on an environment remains, and prompts the search for the new solutions of the problem.
The conventional engine of the internal combustion are constructed under the classical circuit, namely, a cylinder, a piston, a rod and a crankshaft. It is necessary to note, that in traditional engines a number of well-known deficiencies takes place, namely:
1. An inefficient combination of the pressure upon the piston and the tangential force on the crankshaft.
Here it is necessary to note two aspects:
а)The process of the combustion of the mixture begins before the piston arrives at the “top dead point” and it means that the movement of the piston to the ”top dead point” is counteracted by the total pressure: the sum of the degree of the compression, and the increasing pressure of the inflamed mixture, and that results in loss of the power.
b) During the maximal increase of the pressure and the combustion of the significant part of the mixture, the crankshaft turns by the angle from 0 ° up to 90 °. Thus the coefficient of the tangential force to the force working on the piston changes from the value of 0 up to the value of 1.
Thus, during the turn of the crankshaft from 0 up to 90 degrees, the combination of two phenomena is observed:
а) The change of the pressure from maximal up to minimal;
b) The change of a coefficient of the tangential force to the force working on the piston from the value of 0 up to the value of 1. 2.The engine of the internal combustion uses in the best case scenario only 75 % of the fuel and 25 % goes in the exhaust pipe and the muffler. Namely, this part of the fuel is burning in the catalyst. But catalyst is the very expensive device and it requires the substantial part of the powerful of the engine for pumping the fuel through a dense net of the surfaces of the catalyst. There are several reasons for this phenomenon and one of them is the very short time of the process of the burning. The average time of the burning of the fuel in the cylinder is 0.001sec. In other words the effectivity of the engine depends on the length of the motion of the piston. But the length of the motion of the piston is directly related with the size of the crankshaft and this relationship limits the length of the motion of the piston.
3. The significant influence on the fuel efficiency makes also a short time for the exhaustion of the burned mixture. It means that the new portion of the fresh air-gas mixture is mixed with remains of the burned mixture. These phenomenon decreases the powerful of the engine.
4. When the piston is at the “top dead point”, the compressed mixture is ignited. It is known that for the full and complete combustion of the fuel vapor desirable the high temperature and the high pressure. But immediately, when the piston passed the “top dead point”, it starts to move down with the significant increasing of the space above the piston. With the spread of the flame front of the mixture in the combustion chamber the first portions of the mixture will burnt at the high temperature and the high pressure. But the latest portion of the hot mixture burns under the condition of the sharply declining of the pressure and the falling of the temperature. For this reason, the part of the mixture does not have the time to burn or not burn fully.
On the video is shown a two-stroke engine.https://www.youtube.com/watch?v=tVGRqrjPzDw
The engine consists of two pistons (a black main and a red additional), as well as, two valves. The first valve, the intake valve, provides intake of the fresh air-gas mixture into the volume above the additional piston. The second one provides transfer of the compressed fresh air-gas mixture from the volume above the additional piston into the volume above the main piston and separates (closes) volumes above the main and the additional pistons after the ignition of the fuel in the volume above the main piston. There is also a port for the exhaustion. The transfer of the power from the force of the pressure above the main piston to the power shaft is provided by a crémaillère.
There are several differences from the classical engine, namely:
1. In the “top dead points” the piston is motionless while racks run around sprockets. When the piston in the “top dead point” and motionless is created the situation of the possibility for the burning of the mixture in the chamber with the constant volume. It will result to the significant increasing of the pressure and the temperature. The meaning of the pressure and the temperature could be a very high and may result to the destroying of the engine. It means that moment of the time of the ignition of the mixture must be optimized and will allow having the significant optimized pressure and will not allow destroying of the engine. In this case Carnot Cycle will look in a new image.
2. In the “bottom dead point” the piston is motionless, also like in the “top dead point”, while racks run around sprockets. This result to the significant increase of the time for the exhaustion of the burned gas. It means that the inner volume of the cylinder is ready to take the new fresh portion of the air-gas mixture. In the suggested design of the engine two strokes fulfill simultaneously, namely the work stroke (combustion) and the intake stroke. Both strokes are separated. When both (main and additional) pistons move upwards, the fresh air-gas mixture pumped by the additional piston into the volume above the main piston.
3. A distinctive feature of the suggested engine is that the shoulder of tangential force on the power shaft on all way of the moving of the piston remains constant. The change of the magnitude of the torque in this case is defined only by one factor, namely, the change of pressure in the cylinder in the process of the moving of the piston. Statistical meanings of variations of moments in the suggested design and in the design with the crankshaft during the turning of the power shafts from 0 to 180 degrees could be characterized by an average arithmetic values. The average arithmetic value of the moment in the suggested design is 1.83 times greater than the average arithmetic value of the moment in the existing design.
4. Also necessary to note that in the new design of the engine exists possibility significantly increase the length of the motion of the piston that increasing the time for the effective burning of the fuel.
It is natural that both engines must be equipped with flywheels to compensate an uneven rotation.
In conclusion possible to say that suggested engines have a row of advantages that are mentioned above and like classical two-stroke engine it has not a camshaft and valves connected with it. The identified reserves of the capacity allow have the powerful engine with the low number of the revolution that results to decreasing of the thermal intensity, increasing of the reliability and wear resistance and as well as decreasing the fuel consumption and the harmful emission.