Application of 2nd Law of Thermodynamics
Another industry related to the second law of thermodynamics is the air-conditioner. As the weather in this country, Malaysia is always hot and humid, air-conditioners are used to cool down the surrounding inside the house. In fact, the concept of air-conditioner is one of the applications of the second law of thermodynamics which stated that for any process occurring in a closed system, the entropy increases for an irreversible system and remains constant for a reversible system, but never decreases. An air-conditioner functioned by using a working fluid to transfer heat from the colder indoor air to the hotter outside air. So the indoor air will be cooled down to a favorable temperature for indoor activities. Second law of thermodynamics defines as the entropy of an isolated system never decreases due to isolated systems spontaneously evolve towards thermodynamics equilibrium. Air conditioners apply it during its function. Air conditioners are made up of three main components which are evaporator, condenser and compressor. Evaporator located inside used to transfer heat from the indoor atmosphere to the working fluid. Condenser located outdoor will transfer heat from the working fluid to atmosphere outside and lastly compressor do works on the working fluid and provide additional thermal energy so that the total entropy of the system do not reduced. From the diagram above, it is clear to show how second law of thermodynamics apply on the process of air conditioners. At first, the working fluid arrives at the evaporator as a warm and high pressure liquid and it passes through a constrictor which causes a large drop in pressure. It thus enters the evaporator as a warm and low pressure liquid. Because of the low pressure, the working fluid changes its state from liquid to become a gas. Breaking the bonds between the particles requires some thermal energy. Therefore, the working fluid which is in gaseous state becomes quite cold which its temperature less than