clear;
clc;
// Example 7.4
printf('Example 7.4\n\n');
printf('Page No. 204\n\n');

// This question doesnot contain any calculation part.
//Refer figure 7.3, 7.4, 7.5
T_max = 200;// Flue gas exit temperature in degree celcius
printf(' The company investigate four alternative methods of heat abstraction using the flue gas.\n\n  System-1   The efficiency of the furnace without any air preheater is 79.2 per cent.\n  System-2   The efficiency of the furnace, with the air preheater only in the system operating as shown in figure 7.3, is increased to 86.6 per cent.\n  System-3   By the incorporation of the heat exchanger,the furnace efficiency is increased to 93.3 per cent using the arrangement shown in figure 7.4.\n  System-4   Using no preheating,finally achievied an overall thermal  efficiency of 93.7 per cent.\n  \t     The new air preheater scheme is shown in figure 7.5.\n\n The pay-back period in all instances is less than 3.5 years.')