A. Ahmadi - Iran University of Science and Technology School of Advanced Technology Department of Energy Systems Engineering, Tehran, Iran.
M. A. Ehyaei - Department of Mechanical Engineering, Islamic Azad University, Pardis Branch, Pardis, Iran.

Entropy generation can be caused by the energy transfer from a high-temperature recourse to a low-temperature resource; this is defined by the second law of thermodynamics. This phenomenon can occur for the Earth by transferring the solar energy from the sun to the earth. The process of entropy generation of the Earth is an important concept for the life of the earth. This process also has significant effects on the global hydrological cycle, carbon cycle of the Earth’s atmosphere, and global warming. This paper presents an approximate method to estimate the entropy generation of the earth caused by the sun. Application of the heat engine to calculate the entropy generation of the planets has been carried out so far. In this research work, the concept of heat engine is applied to calculate the entropy generation of the earth and the atmosphere surrounding it in a relatively simple model. Based upon this calculation, the rate of entropy generation of the earth and its surrounding atmosphere is . Moreover, by considering this imaginative heat engine, the first and second law efficiencies are equal to 0.11036 % and 0.11546 %, respectively. The results of this research work have also been justified by similar works on this topic.

Entropy, Earth, Atmosphere, Thermodynamic, First Law Efficiency, Second Law Efficiency