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
This assignment will simulate large deformations (nonlinear geometry) and occurrence of necking and buckling due to static tensile and compressive loading of a given elastic-plasti

TYPES OF COATED ELECTRODES Following are the types of coated electrodes: a. Cellulosic electrodes b. Rutile electrodes c. Iron powder electrodes d. Low hydrogen e

Three Particle System Suppose we have two particles of masses  m 1  and  m 2   already fixed in space at distance  r 12  from each other. Let us bring in a third particle of

Occupational Safety - Industrial Safety The bad and most debilitating experience related to work which a worker can have is a work-related accident or illness. Within the effe

Determine the rate of heat removal: Carbon dioxide passing through heat exchanger at rate of 100kg/hr is cooled down from  800 0 C to 50 0 C . Write down the steady flo

(i) Hydraulic press:   This can be used to lift a heavy load placed on the platform of larger piston or to press the things placed among the piston and the heavy platfor

priming and foaming

What is raft foundation? A raft or mat can be considered as a combined footing which covers the entire building area and supports all columns and walls. Such a foundation may c

matlab program of location a point with respect a line

Pipe flanges are protected from corrosion by means of electrolysis, with dielectric flanges. The piping system is electrically insulated by what is known as a sacrificial anode. A