Chapter 4, Problem 4.46P

(a)

Interpretation Introduction

Interpretation:

The required volumetric flow rate of air should be calculated in air conditioning unit with heat transfer rate $12\frac{\text{btu}}{\text{s}}$ raised temperature from ${70}^{\text{o}}\text{F}$ to ${90}^{\text{o}}\text{F}$ .

Concept Introduction:

The transfer of heat in steady-flow exchangers for a gas is given as:

$Q=\Delta H=R{\displaystyle \underset{T_0}{\overset{T}{\int }}\frac{\Delta C_P}{R}dT}$.......(1)

Where $\Delta H$ is heat of reaction at any temperature $T$ .

and

${\displaystyle \underset{T_0}{\overset{T}{\int }}\frac{\Delta C^{\circ }{}_P}{R}dT}=A{T}_0(\tau -1)+\frac{B}{2}{T}_0{}^2({\tau }^2-1)+\frac{C}{3}{T}_0{}^3({\tau }^3-1)+\frac{D}{T_0}(\frac{\tau -1}{\tau })$.......(2)

Where $\tau =\frac{T}{T_0}$

(b)

Interpretation Introduction

Interpretation:

The required volumetric flow rate of air should be calculated in air conditioning unit with heat transfer rate $12\frac{\text{kJ}}{\text{s}}$ raised temperature from ${24}^{\text{o}}\text{C}$ to ${37}^{\text{o}}\text{C}$ .

Concept Introduction:

The transfer of heat in steady-flow exchangers for a gas is given as:

$Q=\Delta H=R{\displaystyle \underset{T_0}{\overset{T}{\int }}\frac{\Delta C_P}{R}dT}$........(1)

Where $\Delta H$ is heat of reaction at any temperature $T$ .

and

${\displaystyle \underset{T_0}{\overset{T}{\int }}\frac{\Delta C^{\circ }{}_P}{R}dT}=A{T}_0(\tau -1)+\frac{B}{2}{T}_0{}^2({\tau }^2-1)+\frac{C}{3}{T}_0{}^3({\tau }^3-1)+\frac{D}{T_0}(\frac{\tau -1}{\tau })$......(2)

Where $\tau =\frac{T}{T_0}$