Study and Development of Compressed Air Engine-Single Cylinder: A Review Study
This paper is reports on the review of compressed air engine for the design and development of single cylinder engine which can be run by the compressed air. Current four strokes single cylinder engine (bikes/moped) can be run on the compressed air with a few modifications that are the main objective of the study. Compressed air filled by electricity using a compressor. The electricity requirement for compressing air has to be considered while computing overall efficiency. Nevertheless the compressed air vehicle will contribute to reducing a air pollution and tend to zero pollution level and promoting great environment. Main advantage of this engine is that no hydrocarbon fuel required means no combustion process is take place. HISTORY In fact, two centuries before that Dennis Papin [6] apparently came up with the idea of using compressed air (Royal Society London, 1687). In 1872 the Mekarski [6] air engine was used for street transit, consisting of a single stage engine. Numerous locomotives were manufactured and a number of regular lines were opened up (the first in Nantes in 1879). In 1892, Robert Hardie [6] introduced a new method of heating that at the same time served to increase the range of the engine which in turn helped to increase the distance that could be traveled at a stretch. One of its new features was regenerative braking. By using the engine as a compressor during deceleration, air and heat were added to the tanks, increasing the range between fill-ups. However, the first urban transport locomotive was not introduced until 1898, by Hoadley and Knight [6] , and was based on the principle that the longer the air is kept in the engine the more heat it absorbs and the greater its range. As a result they introduced a twostage engine. Charles B. Hodges [6] will always be remembered as the true father of the compressed air concept applied to cars, being the first person, not only to invent a car driven by a compressed air engine but also to have considerable commercial success with it. After twelve years of research and development, Guy Negre [6] has developed an engine that could become one of the biggest technological advances of this century. A French engineer by profession, he has designed a low consumption and low pollution engine for urban motoring that runs on compressed air technology. “air car” from Motor Development International is a significant step for zero emission transport, delivering a compressed air-driven vehicle that is safe, quiet, has a top speed of 110 km/h and a range of 200 km. Guy Nègre is the head of Research and Development at Moteur Development International (MDI) cars, where the Zero Emission Vehicle (ZEV) prototype has been in production since 1994. INTRODUCTION It is hard to believe that compressed air can be used to drive vehicles. However that is true and “air car” as it popularly knows has caught the attention of research worldwide. It has zero emission and is ideal for city driving condition. MDI (Moteur Development International) is one company that holds the international patents for compressed air car. This review study reveals aim is to run the four strokes bike with help of compressed air, it will try to achieve a 50 km/h speed and range of refilling compressed air is after running of 70-80 km. Two technologies have been developed to meet different need (1) Single energy compressed air engines. (2) Dual energy compressed air plus fuel engines The single energy engines will be available in both Minicats and Citycats. These engines have been conceived for city use, where the maximum speed is 50 km/h and where MDI believes polluting will soon be prohibited with use of compressed air technology which having zero pollution level. The dual energy engine, on the other hand, has been conceived as much for the city as the open road and will be available in all MDI vehicles. The engines will work exclusively with compressed air while it is running under 50 km/h in urban areas. But when the car is used outside urban areas at speeds over 50 km/h, the engines will switch to fuel mode. The engine will be able to use gasoline, gas oil, biodiesel, gas, liquidized gas, ecological fuel, alcohol, etc. Both engines will be available with 2, 4 and 6 cylinders, When the air tanks are empty the driver will be able to switch to fuel mode, by car’s on board computer. ENGINE WORKING High pressure air is introduced to the engine that pushes the piston and creates movement. The atmospheric temperature is used to re-heat the engine and increase the road coverage. The air condition system makes use of the expelled cold air. Due to there is no pollution, oil change is necessary every 50,000 km. REVIEW OF PREVIOUS RESEARCH WORK No more working on the single cylinder four strokes engine. but here few research is outlined as given below related to compressed air engine. Air fuelled zero emission road transportation: A comparative study Haisheng Chen et al. [1], adopted two technologies typical compressed air and liquid air power systems. Figure shows schematic diagram and working of International Journal of Advanced Engineering Technology E-ISSN 0976-3945 IJAET/Vol.III/ Issue I/January-March, 2012/271-274 cycle on temperature – entropy diagram for the both systems. As per author’s knowledge and belief only few works reported on this study. Figure-1 Compressed air engine [1] Figure 2 Liquid air engine [1] Figure 3 T–S diagram of engines Compressed air
THERMODYNAMIC ANALYSIS OF COMPRESSED AIR VEHICLE PROPULSION
The fist compressed air vehicles were built by Andraud and Tessie du Motay in Paris between 1838 and 1840. Since then the idea has been tried again and again, but has never reached commercialization. In recent years the French developer MDI has demonstrated advanced compressed air vehicles. However, the claimed performance has been questioned by car manufacturers and automobile expert. Basically, when referred to ambient conditions, the relatively low energy content of the compressed air in a tank of acceptable volume is claimed to be insufficient to move even small cars over meaningful distances. On the other hand, another air car developer claims to have driven 184 km on one 300 Litre filled with air at initially 300 bar pressure. Obviously, there are issues to be resolved, not by heated debates, but by an analysis of the thermodynamic processes involved. This is the aim of this study. The results indicate that both sides are correct. At 20°C a 300 Litre tank filled with air at 300 bar carries 51 MJ of energy. Under ideal reversible isothermal conditions, this energy could be entirely converted to mechanical work. However, even under isentropic conditions (no heat is exchanged with the environment or generated by internal friction) not more than 25 MJ become useful. By multi-stage expansion with inter-stage heating the expansion process is brought closer to the isothermal ideal. The analysis is extended to the compression of air. Again, the ideal isothermal compression is approached by multi-stage processes with inter-cooling. By this approach compression energy requirements are reduced to acceptable levels and system pressure and temperature are kept within safe limits. The results of this analysis seem to indicate that the efficiency of the four-stage expansion process is acceptable, while even a four-stage air compression with inter-cooling is associated with significant losses. However, the overall energy utilization could be increased if the waste heat generated during the air compression process would be used for domestic water and space heating. It seems that there is some justification for continuing the development of compressed air cars. However, it would be useful to establish the performance of such vehicles by an endurance race under controlled conditions in the presence of the general public.
Introductory Study of Variable Valve Actuation for Pneumatic Hybridization
Urban traffic involves frequent acceleration and deceleration. During deceleration, the energy previously used to accelerate the vehicle is mainly wasted on heat generated by the friction brakes. If this energy that is wasted in traditional IC engines could be saved, the fuel economy would improve. One solution to this is a pneumatic hybrid using variable valve timing to compress air during deceleration and expand air during acceleration. The compressed air can also be utilized to supercharge the engine in order to get higher load in the first few cycles when accelerating. A Scania D12 single-cylinder diesel engine has been converted for pneumatic hybrid operation and tested in a laboratory setup. Pneumatic valve actuators have been used to make the pneumatic hybrid possible. The actuators have been mounted on top of the cylinder head of the engine. A pressure tank has been connected to one of the inlet ports and one of the inlet valves has been modified to work as a tank valve. The goal has been to test and evaluate 2 different modes – compression mode (CM) where air is stored in an air tank during deceleration and air-motor mode (AM) where the previously stored pressurized air is used for accelerating the vehicle. This paper also includes an optimization of the CM.