Chapter 5, Problem 5.2NP

(a)

Interpretation Introduction

Interpretation:

The efficiency of a Carnot engine operation under conditions where the outlet and condensate temperatures are: 540°C and 30°C respectively needs to be deduced

Concept Introduction:

The efficiency (e) of a Carnot engine is a function of the reservoir temperatures and can be expressed as:

  $\text{ε = 1}-\frac{{\text{T}}_{\text{hot}}}{{\text{T}}_{\text{cold}}}\text{ ------(1)}$

(b)

Interpretation Introduction

Interpretation:

The total efficiency of the power generating unit needs to be deduced based on the given individual unit efficiencies.

Concept Introduction:

The total efficiency is given as a product of the individual efficiencies,

  ${\text{Total Efficiency = ε}}_{\text{1}}{\text{×ε}}_{\text{2}}\text{×}\mathrm{...}{\text{ε}}_{\text{n}}\text{ ------(2)}$

Where e₁, e₂…..are the efficiencies of the individual units

(c)

Interpretation Introduction

Interpretation:

The amount of coal required per hour at its peak output needs to be calculated.

Concept Introduction:

The efficiency of an engine is also given in terms of the ration of the energy output to the heat input

  $\text{ε = }\frac{{\text{E}}_{\text{output}}}{{\text{q}}_{\text{input}}}\text{ ------(3)}$