Example of change of enthalpy, Mechanical Engineering

Example of change of enthalpy:

Q 0.5kg/s of a fluid flows in steady state process. The properties of fluid at the entrance are measured as p1 = 1.4bar, density = 2.5kg/m3, u1 = 920Kj/kg while at exit properties are p= 5.6 bar, density = 5 kg/m3, u2 = 720Kj/kg. The velocity at entrance is 200m/sec, while at exit it is 180m/sec. It rejects 60kw of heat and rises through 60m during the flow. Find change of enthalpy and rate of work done.     

Sol: Given that:

mf  = 0.5kg/s

P1  = 1.4bar, density = 2.5kg/m3,

u1  = 920Kj/kg

P2  = 5.6 bar, density = 5 kg/m3,

u2  = 720Kj/kg. V1  = 200m/sec

V2  = 180m/sec Q = - 60kw

Z2  - Z1  = 60m h = ?

WS  = ?

Since           h2 - h1  =   U +   P

h2 - h1  = [U2  - U1    + (P2/  2  - P1/   1)]

= [(720 -920) × 103  +   (5.6/5 - 1.4/2.5) × 105]

= [-200 × 103  + 0.56 × 105] = - 144KJ/kg

H =  mf  × (h2 - h1) = 0.5 × (-144) Kj/kg = -72KJ/sec                    .......ANS

By Applying SFEE

84_Isentropic flow through the nozzle3.png

60 × 103  - WS  = 0.5[ - 144 × 103  + (1802  - 1002)/2 + 9.81 × 60]

WS  = 13605.7 W = 136.1KW                    .......ANS

Posted Date: 10/16/2012 6:33:39 AM | Location : United States







Related Discussions:- Example of change of enthalpy, Assignment Help, Ask Question on Example of change of enthalpy, Get Answer, Expert's Help, Example of change of enthalpy Discussions

Write discussion on Example of change of enthalpy
Your posts are moderated
Related Questions
Q. Resource Management for project? An important factor in overall project success is the provision of suitable and adequate resources. The initial estimate of engineering man

National supply and national demand curves: 1. Explain why neighboring countries tend to trade extensively with each other. 2. Use Table 1.1 to find the five most open econ

Displacement or Swept Volume ( V s ) : The nominal volume swept by the working piston when travelling from one dead centre to the other is called the displacement volume. It is e

First law of thermodynamics: The First Law of Thermodynamics states that work and heat are equally convertible. The present tendency is to include all the forms of energy. The

Thermodynamic process - Thermodynamics: Thermodynamic system undergoes changes because of the energy and mass interactions. Thermodynamic state of system changes because of th

Wet saturated steam -  thermodynamics: we t saturated steam Wet steam is a 2-phase mixture comprising of boiling water particles and dry steam in equilibrium state. Its for

how to find the equation for deflection of a cantilever beam subjected to udl in terms of Airy''''s stress function

Break even analysis: The costs from Shagun Palace, a continental restaurant, are shown below. Fixed costs are Rs. 50,000 per month. Break even analysis is applied as a

Dryness fraction measurement: Sensible Hea t of Water or Heat of Liquid or Enthalpy of Liquid (h) Sol.: It is quantity of heat which is required to raise unit mass

What is the limition of kkleins constraction?