The enthalpy-entropy chart, also known as the Mollier diagram, has several technical applications. It is widely used to estimate the enthalpy of pure substances and mixtures of substances most frequently found in Engineering. The Mollier chart serves to simplify calculations of enthalpy, entropy, pressure, temperature, specific volume and quality of steam and water. The Mollier diagram is the representation of the properties of water and water vapor. A master SA (Enthalpy-Entropy) coordinate system is used. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essaySourceThe diagram was created in 1904 when Richard Mollier plotted total heat versus entropy. At the 1923 Thermodynamics Conference held in Los Angeles, it was decided to call, in his honor, a "Mollier diagram" any thermodynamic diagram that used the enthalpy h as one of its axes. Constant pressure lines and enthalpy lines. The horizontal lines are the lines of constant pressure, while the vertical lines are the lines of constant "enthalpy", which is the amount of heat present in one pound of refrigerant. Note that the pressures are absolute pressures and that the scale is logarithmic. Enthalpy. Although enthalpy is sometimes referred to as "total heat", it is more correctly and specifically defined as the sum of all the energy supplied by a given mass of matter under any thermodynamic conditions. Below is the formula for calculating enthalpy.h = u+pv/jwhere:H: enthalpy (kcal/kg)U: internal energy (kcal//kg)P: absolute pressure (kgf/cm2)V: specific volume (m3/kg)J: equivalent mechanical energy. Saturated liquid line and saturated vapor line. As the following figure shows, the diagram is divided into three main parts separated by the saturated liquid line and the saturated vapor line. The part to the left of the saturated liquid line is called the "subcooled zone". At any point in the subcooled zone, the refrigerant is in a liquid state and its temperature is lower than the saturation temperature corresponding to its pressure. The part to the right of the saturated vapor line is called the "recharged zone". In this part, the refrigerant is in the form of superheated vapor. The middle part of the table, between the saturated liquid and saturated vapor lines, is called the "phase change zone", which represents the phase change of the refrigerant between the liquid and vapor states. At any point between the two lines, the refrigerant appears as a mixture of liquid and vapor. As seen in the previous figure, the point of union between the saturated liquid line and the saturated vapor line is called the "critical point". The temperature and pressure at this point are called "critical temperature" and "critical pressure" respectively. Critical temperature. The critical temperature of a gas is the highest temperature at which that gas can be condensed by the application of pressure. The critical temperature varies depending on the types of gas. Dry steam lines. The phase change from liquid to vapor occurs progressively from left to right while the phase change from vapor to liquid occurs from right to left. The mixture of liquid and vapor near the saturated liquid line is a nearly pure liquid. In contrast, the mixture of liquid and vapor near the saturated vapor line is almost pure vapor. Please note: this is just an example. Get a custom paper from our expert writers now. Get a custom essay The "dry steam" lines that extend from the critical point to the bottom through the middle section of the.