Our paper examines the capability of several energy conversion processes to provide sufficient energy in a world where the non-renewable resources are getting depleted.Moreover pollution caused by them is increasing at a rapid rate. One such efficient and non-polluting means of running the vehicles is the use of liquid nitrogen. To use liquid nitrogen as a non-polluting fuel, a multiple reheat open Rankine and a closed Brayton cycle are used. As a proof of the principle of using liquid nitrogen as a fuel, an automobile was converted to run on liquid nitrogen in 1997. Earlier work has shown that the energy available by operating various thermodynamic cycles between atmospheric temperatures and liquid nitrogen temperatures can provide more energy per unit mass than is available from current lead acid batteries.
Cryogenic can be defined as the branch of the physics that deals with the production of and study of effects and very low temperature. It is mainly concerned with temperatures found in range of 150 Degree C to absolute zero (-273.15 Degree C). Various Cryogenic Fluids are Liquid Helium and Liquid Nitrogen
Cryogenic Heat Engine
It is a engine which uses very cold substances to produce useful energy. A unique feature of an cryogenic heat engine is that it operates in an environment at the peak temperature of the power cycle, thus, there is always some heat input to the working fluid during the expansion process.
Liquid Nitrogen is the cheapest, widely produced and most common cryogenic liquid. It is mass produced in air liquefaction plants. The liquefaction process is very simple in it normal, atmospheric air is passed through a dust precipitator and pre-cooled using conventional refrigeration techniques. It is then compressed inside large turbo pumps to about 100 atmospheres. Once the air has reached 100 atmospheres and has been cooled to room temperature it is allowed to expand rapidly through a nozzle into an insulted chamber. By running several cycles the temperate of the chamber reaches low enough temperatures the air entering it starts to liquefy. Liquid nitrogen is removed form the chamber by fractional distillation and is stored inside well insulated Dewar flasks.
How does the Nitrogen Powered car work ?
Heat from the atmosphere vaporizes liquid nitrogen under pressure and produces compressed nitrogen gas. This compressed gas runs a pneumatic (compressed gas drive) motor with nitrogen gas as the exhaust. Main Components of the Engine are
- A pressurized tank to store liquid nitrogen
- A heat exchanger that heats (using atmospheric heat) liquid nitrogen to form nitrogen gas, then heats gas under pressure to near atmospheric temperature.
- A pneumatic motor (along with a Volkswagen transmission) that runs the car.