Category: Properties of Steam

Determine the condition of steam in the following cases: Solution Given p = 10 bar; t = 200°C; v = 0.175 m3/kg Example 2.2 Calculate the quantity of heat required to generate 1 kg of steam at a pressure of 8 bar from water at 30°C (a) when dryness fraction is 0.9, (b) when steam is just dry, and (c) when…

The different methods commonly used for the measurement of dryness fraction of steam are as follows: The working principle of all the calorimeters is to bring the state of the substance from the two-phase region to the single phase region (either compressed liquid or superheated vapour region). This is because in the two-phase region, pressure…

In Mollier diagram (Fig. 2.3), the vertical ordinate represents the enthalpy and the horizontal ordinate represents the entropy. The regions above and below the saturation line represent the superheated and wet conditions of steam, respectively. The lines of constant dryness fraction are shown in the wet steam region, whereas the lines of constant temperature and…

It is the plot of the saturation temperature of water and steam corresponding to various absolute pressure vs entropies at those saturation temperatures, as shown in Fig. 2.2. The curve on the left marked water line (saturated liquid line) shows the relationship between entropy and temperature before steam is formed. The dry steam line (saturated vapour…

In actual practice, it is quite cumbersome to calculate the relation between various quantities such as pressure, temperature, volume, enthalpy, latent heat and entropy, etc., of steam. Such quantities have been determined experimentally and recorded in the form of tables known as steam tables. Steam table is a complete data book that contains various properties, like…

Consider 1 kg of ice under atmospheric pressure and at a temperature of −10°C contained in a vessel. If we heat the ice gradually keeping the pressure constant, the following changes will take place, as shown in Fig. 2.1: Figure 2.1 Constant pressure temperature-heat added diagram for steam and water

A pure substance may be defined as a system that has the following characteristics: Examples of pure substance are atmospheric air, mixture of steam-water, combustion products of a fuel, etc.