Estimate the gross heating value and net heating value of pentane if the reactants and products are
The combustion reaction is given by
C5H12 (g) + 8O2(g) 5CO2 (g) + 6H2O (g)
The standard heat of the above reaction is estimated
Determine the enthalpy of water at 100o C and 15 MPa (a) by using compressed liquid
tables, (b) by approximating it as a saturated liquid, and (c) by using the correction factor.
At 100oC, the saturation pressure of water is 101.35 kPa, and since P>P sat,
Limitations of First Law
First law is a statement of conservation of energy principle. Satisfaction of first law alone does
not ensure that the process will actually take place.
A cup of hot coffee left in a cooler room eventually co
To define a temperature scale that does not depend on the thermometric property of a
substance, Carnot principle can be used since the Carnot engine efficiency does not
depend on the working fluid. It depends on the temperatures of the reservoirs between
Heat exchangers are devices where two moving fluid streams exchange heat without mixing.
Heat is transferred from the hot fluid to the cold one.
Under steady operation, the mass flow rate of each fluid stream flowing through a heat
exchanger remains const
1. has the same value irrespective of path as long as path is reversible
2. is an exact differential of some function which is identical as entropy
4. for reversible process only
Calculation of Entropy change
Entropy is a state function. The entropy
Molecules of a system pass energy in various forms such as sensible and latent energy (associated with
change of state), chemical energy (associated with the molecular structure), and nuclear energy
(associated with the atomic energy).
During a chemical r
Most of the fuels contain Carbon and Hydrogen and are in solid, liquid or in gaseous
Solid Fuels (Coal): Consists of moisture, volatile matter, fixed carbon and ash.
The analysis specifies on a mass basis, the relative amounts of these
Thermodynamic Temperature Scale
Now, there are several functional relations that will satisfy this equation.
thermodynamic scale of temperature, Kelvin selected the relation
Q1/Q2 = T1/T2
That is, the ratio of energy absorbed to the energy rejecte
The Carnot cycle uses only two thermal reservoirs one at high temperature T 1 and the
other at two temperature T2.
If the process undergone by the working fluid during the cycle is to be reversible, the heat
transfer must take place with no temperature di
When wet steam is throttled to a low pressure (usually atmospheric), steam becomes
The temperature of the superheated steam is measured.
Knowing the pressure and temperature of the steam in the calorimeter, its enthalpy can be