Exergy Analysis of Reacting and Psychrometric SystemsLiquid octane (C8H18) at 25°C, 1 atm...

Exergy Analysis of Reacting and Psychrometric Systems

Liquid octane (C8H18) at 25°C, 1 atm and a mass flow rate of 0.57 kg/h enters an internal combustion engine operating at steady state. The fuel burns with air entering the engine in a separate stream at 25°C, 1 atm. Combustion products exit at 670 K, 1 atm with a dry molar analysis of 11.4% CO2, 2.9% CO, 1.6% O2, and 84.1% N2. If the engine develops power at the rate of 3 kW, determine

(a) the rate of heat transfer from the engine, in kW.

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(b) an exergetic efficiency for the engine.

Use the environment of Problem 13.91 and neglect the effects of motion and gravity.

Problem. 13.91

Using Chemical Exergy

Applying Eq. 13.36 for (a) carbon, (b) hydrogen (H2), (c) methane, (d) carbon monoxide, (e) nitrogen (N2), (f) oxygen (O2), and (g) carbon dioxide, determine the chemical exergy, in kJ/kg, relative to the following environment in which the gas phase obeys the ideal gas model:

(13.36)