Chapter 5, Problem 5.43P

(a)

Interpretation Introduction

Interpretation:

Determine entropy generation in kJ.K-1.

Concept Introduction:

The entropy generation takes place by means of three ways, first is entropy generationdue to the direct heat transferred from the hot reservoir to two cooler reservoirs, second entropy generation due to addition of heat to cooler reservoir $T_1$and third is entropy generation due addition of heat to cooler reservoir $T_2$ . Hence, the total entropy generation is

  $S_G=-\frac{Q_H}{T_H}+\frac{Q_1}{T_1}+\frac{Q_2}{T_2}$   .....(1)

(b)

Interpretation Introduction

Interpretation:

Determine lost work and comment on how the process could be made reversible.

Concept Introduction:

The entropy generation in the surrounding is calculated by following formula

  $S_G=\frac{W_{\text{lost}}}{T_{\sigma }}$

Hence the lost work during the process is

  $W_{\text{lost}}=S_G{T}_{\sigma }$

   .....(1)