The First Law of Thermodynamics

1st Law of Thermodynamics - The first Law is related to conservation of energy in simple words it explains that energy can neither be created nor be destroyed it can be converted from one form to other. Law of thermodynamics defines relations between physical quantities i.e. temperature, energy, and entropy. The relation of these physical quantities can be given in different ways relating with Work, Internal Energy of a system [1].

Applications of 1st law of thermodynamics:

Heat Engine – Heat engines are designed on the basic of 1st Law, it is an idealization of a set of processes used by spark ignition internal combustion engines. The engines ingest a mixture of fuel and air, which is then compressed by a piston cylinder arrangement, which causes fuel it to react, thus effectively adding heat through converting chemical energy into thermal energy, that leads to expansion of the combustion products, and then eject the combustion products and replace them with a new charge of fuel and air. Therefore chemical reaction is converted into rotational motion along with heat is released into the environment [3].

Refrigerators - The second main application of 1st Law in which the objective of a refrigerator is to lower the internal energy of a body at low temperature and transfer that energy to the higher temperature surroundings [3]. It requires work to do this. The medium for the energy exchange is a working fluid that circulates in a loop through a number of devices. These devices exploit to increase and eliminate energy from the working fluid. As the refrigerant circulates around the loop, its internal energy is alternately raised and lowered by a series of device.

Turbine- Turbine engines, are most widely used for jet propulsion and f...

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...es upwards and removes all the exhaust gases inside the cylinder at constant pressure.

Carnot Cycle - Carnot’s cycle shows that heat is absorbed from the high temperature reservoir and rejected at low temperature reservoir that can be said as foundation to second law of thermodynamics. The law states that the regular movement of heat is from high temperature tank to low temperature tank, and to move it from low temperature reservoir to high temperature reservoir external work has to be done [1].

Diesel Engine - The Diesel Engine is an application of 2nd law of thermodynamics. It is similar to the Otto cycle, the fuel used is different which makes working of the engine different, thought output is rotational motion .the compression ratio is much high as compared to any other as no spark plug is used only adiabatic compression ration leads to burning of fuel [4].