Abstract

German physicist Rudolf Clausius states that energy cannot be transferred from a low-temperature source to a high-temperature source unless there is a certain amount of work input to the system which allows it to happen. Known as the Second Law of Thermodynamics, this statement is the fundamental discipline behind the working principles of such devices as heat pumps or refrigerators. In heat pumps, energy input by work is transferred to the system in the way of mechanical or electrical through the compressor. This work input is used to create a differential relationship between the refrigerant and the cooling/heating process through the condenser and evaporator. The answer to "Through what this cooling/heating process occurs" determines the type of heat pump. However, regardless of their type heat pumps work with the simple principle of Clausius's Statement. In this report, types, working principles, working cycle and the impact of the refrigerant of heat pumps have been investigated. The results of this report can be used as a fundamental explanation of heat pump investigation.