Chapter 7, Problem 7.28P

Interpretation Introduction

(a)

Interpretation:

The rate $\left(\frac{\text{kg}}{\text{h}}\right)$ at which steam is produced needs to be determined.

Concept introduction:

The energy balance is the first law of thermodynamics in which energy can be neither created nor be destroyed is given as follows:

$\Delta H+\Delta E_k+\Delta E_p=Q+W$

$\begin{array}{l}\text{Here,}\\ \text{ΔH= Change in Enthalpy}\\ {\text{ΔE}}_{\text{k}}\text{= Change in Kinetic Energy}\\ {\text{ΔE}}_{\text{p}}\text{= Change in Potential Energy}\\ \text{Q= Heat}\\ \text{W= Work}\text{done}\end{array}$

Interpretation Introduction

(b)

Interpretation:

The volumetric flowrate of the steam produced by using steam tables needs to be determined.

Concept introduction:

The volumetric flowrate $\left(\text{V}\right)$ is equal to the product of specific volume of steam and the rate at which steam produced is given as follows;

$\text{V=}\left(\text{m}\right)\text{×}\left(\text{<mover accent="’true'"><mo>V</mo><mo>^</mo></mover>}\right)$

Interpretation Introduction

(c)

Interpretation:

The volumetric flowrate by assuming the ideal gas behaviour needs to be determined and compared with volumetric flowrate calculated using steam tables.

Concept introduction:

The ideal gas equation is given as follows;

$\begin{array}{l}\text{P<msup><mo>V</mo><mo>′</mo></msup>=nRT}\\ \text{<msup><mo>V</mo><mo>′</mo></msup>=}\frac{\text{nRT}}{\text{P}}\\ \text{<msup><mo>V</mo><mo>′</mo></msup>=}\frac{\text{mRT}}{\text{MP}}\end{array}$

The molar mass of water is 18 g/mol thus,

$\begin{array}{l}\text{In one mole of water, there are 18 grams are present}\\ \text{So, 1mol=18g}\end{array}$

Interpretation Introduction

(d)

Interpretation:

The effect on the 35% of the thermal energy released due to the combustion process that does not produces steam needs to be explained.

Concept introduction:

Thermal energy is defined as energy coming from heat. The heat is produced due to the movement of tiny particles in an object. Amount of geat generated depends on the speed of the particles.