Chapter 7, Problem 7.33P

Interpretation Introduction

(a)

Interpretation:

Write an energy balance on the turbine and calculate the outlet stream temperature.

Concept introduction:

First law of Thermodynamics for a closed system.

$\Delta u+\Delta E_k+\Delta E_p=Q-W$

The right hand side of the equation gives the total energy transferred to the system and the left hand side gives gain in total energy of the system.

The definitions of the symbols are $\Delta u$ = Change in internal energy, $\Delta E_k$ = Change in kinetic energy, $\Delta E_p$ = Change in potential energy, $Q$ = Heat added to system and $W$ = Work done by the system

Interpretation Introduction

(b)

Interpretation:

Write an overall energy balance equation for the heater and calculate the required input to steam.

Concept introduction:

First law of Thermodynamics for a closed system.

$\Delta u+\Delta E_k+\Delta E_p=Q-W$

The right hand side of the equation gives the total energy transferred to the system and the left hand side gives gain in total energy of the system.

The definitions of the symbols are $\Delta u$ = Change in internal energy, $\Delta E_k$ = Change in kinetic energy, $\Delta E_p$ = Change in potential energy, $Q$ = Heat added to system and $W$ = Work done by the system

Interpretation Introduction

(c)

Interpretation:

Verify that the overall energy balance on the units are satisfied.

Concept introduction:

First law of Thermodynamics for a closed system.

$\Delta u+\Delta E_k+\Delta E_p=Q-W$

The right hand side of the equation gives the total energy transferred to the system and the left hand side gives gain in total energy of the system.

The definitions of the symbols are $\Delta u$ = Change in internal energy, $\Delta E_k$ = Change in kinetic energy, $\Delta E_p$ = Change in potential energy, $Q$ = Heat added to system and $W$ = Work done by the system

Interpretation Introduction

(d)

Interpretation:

Show that it is reasonable to neglect the change in kinetic energy for this unit.

Concept introduction:

First law of Thermodynamics for a closed system.

$\Delta u+\Delta E_k+\Delta E_p=Q-W$

The right hand side of the equation gives the total energy transferred to the system and the left hand side gives gain in total energy of the system.

The definitions of the symbols are $\Delta u$ = Change in internal energy, $\Delta E_k$ = Change in kinetic energy, $\Delta E_p$ = Change in potential energy, $Q$ = Heat added to system and $W$ = Work done by the system