Problem 10.6 - Cooling Tower for the Cogeneration System for Ohio University

Recall Problem 8.2, in which Athenai Power Consulting proposed a cogeneration system for Ohio University to provide both 1 MW electric power and hot water at around 60°C. The Athens City Council was somewhat perturbed at the large possible flow rate of water to the Hocking river heated by 10°C, thus Athenai decided to evaluate using an induced draft cooling tower, as shown in the following schematic diagram:

Notice that the condenser cooling load is shared between the hot water heating system and an induced draft cooling tower, thus the cooling tower circulating pump can be controlled as needed based on the hot water heating requirement.

Justify all values used and derive all equations used starting from the basic energy equation for a flow system, mass flow rate equations similar to those developed in Chapter 10c, and the basic definition of thermal efficiency (ηth).