The current research is connected with the theory and construction of a zero emission heat engine. Precisely mechanical engineering is able to provide the purest eco-friendly engine to reduce harmful emissions and stop the greenhouse effect. The actual research question, which I investigate, is the way a zero emission heat engine can be designed. According to the latest explorations, such kind of engine is based on specific liquids, including cryogen and nitrogen. The liquids, used for the zero emission heat engine, provide a specific medium, which contributes to the expansion of gas and heat processes. The heat, excluded from the energy, provided by the gas, turns into a mechanical energy. The amount of the surpassed mechanical energy matches the amount of nitrogen, used to provide the heat. It is interesting that the operation of the zero emission heat engine is similar to the work of steam-driven engine. Both engines use the mechanism of vaporization, although the open-cycle steam-driven engine uses water vaporization, while the zero emission heat engine uses nitrogen vaporization. The system of the zero emission heat engine is simple and consists of a tank for the nitrogen, an exchanger of the heat, and pneumatic mechanism.
As well as the nitrogen vaporization does not influence negatively the atmosphere, using the zero emission heat engine is one of the most appealing investigations for the mechanical engineers. In comparison to burning the fuels, using the nitrogen-based heat engine can be referred to the non-polluting sources of energy. One of the main concerns, which the current research has, is how liquid nitrogen can be produced. It is known that the production of the liquid nitrogen needs intensive use of energy. However, today, the researchers strive to investigate how the liquid nitrogen can be produced using the solar energy. As a result, solar energy-based liquid nitrogen and eco-friendly zero emission heat engine can become the true breakthrough in the contemporary mechanical engineering, which is aimed at protection the environment.