Print this page Cooling Water Systems - An Overview of Cooling Towers
A. Bhatia, B.E.
Course Outline
This 4-hour course
provides comprehensive information on Cooling Towers. Cooling towers find application
in almost all sorts of industries varying from small process plants to the large
refineries, petrochemical complexes, fertilizer plants, manufacturing units
and power plants. It is difficult to imagine an industry without a cooling tower.
The air-conditioning systems for large facilities like commercial complexes,
hospitals, hotels, theaters, airports, residential complexes and shopping arcades
etc. rely on the heat rejection through cooling towers.
The course describes the practical overview of basics, types and selection considerations
of the cooling tower systems. The course is intended for use primarily to the
students, end users, consultants, architects, contractors and plant designers.
The course focuses on the practical aspects of selection and is a recommended
guide for the beginners and experience people involved in conceptualizing and
specifying Cooling Towers
This course includes
a multiple-choice quiz at the end, which is designed to enhance the understanding
of the course materials.
Learning Objective
At the conclusion of this course, the student will:
- Be able to recognize the different types of heat rejection cooling systems;
- Be knowledgeable about the selection aspects of cooling towers; and
- Be able to conceptualise,
judge and select the right system.
Most industrial processes and comfort applications need cooling water for efficient and proper operation. Cooling water systems are an integral part of process operations in many industries.
Unless specific temperatures and pressures are maintained, many industrial and utility processes will not work effectively or efficiently. Cooling water systems control temperatures and pressures by transferring heat from hot process fluids into the cooling water, which carries the heat away. As this happens, the cooling water heats up and must be cooled before it can be used again or replaced with fresh make-up water.
Several factors make water an efficient coolant. Water is available in plenty, readily available, inexpensive, can be easily handled and can carry large amount of heat per unit volume. It does not expand or compress significantly within normally encounters temperature ranges. This makes water the best available cooling media.
The course provides
15 sections that is comprehensive compilation of major aspects related to cooling
tower systems.
Course Content
The the course content is in a PDF file Cooling Water Systems - An Overview of Cooling Towers. You need to open or download this document to study this course.
Course SummaryThe most critical
value in determining cooling tower efficiency and size is the wet bulb temperature
of entering air.
Wet bulb temperature is a measurement of maximum cooling capability of air and
is a function of the actual (dry bulb) temperature and moisture content (relative
humidity) of the air.
Range and Approach are two most important parameters associated with cooling
towers. The sizing of cooling tower varies directly as a function of heat load
and inversely as range and approach.
Cooling towers sized to handle water flow below 10000 GPM are classified as
factory built package towers and the sizes above this limit are generally field
fabricated.
To select a cooling tower, the water flow rate, water inlet temperature, water
outlet temperature and ambient wet bulb temperatures must be known.
The cooling tower could be natural draft that finds usage mainly in power generation
facilities. Most of the industry, process or air-conditioning applications rely
on the use of mechanical draft-cooling towers. The mechanical draft cooling
towers are further classified as the counter-flow or the cross -flow type depending
upon the 'Fill' arrangement and the way air comes in contact with water.
The cooling towers use wood, galvanized steel, stainless steel, concrete and
fiberglass as the major fabrication materials.
The other important factors that guide the overall performance of the system
include the layout & installation considerations to keep the tower free
from obstructions, health hazards such as Legionella disease, water treatment,
energy efficiency, environment and acoustic concerns.
The testing and performance of cooling tower is governed by the guidelines of
Cooling Tower Institute (CTI) standards.
Related Reading
Cooling Water
Treatment
Cooling tower being open to atmosphere is prone to Algae, fungi and microbiological
attack. Also water containing turbidity, other suspended impurities and air
borne contaminants (debris) aggravate the situation that lead to fouling of
equipment downstream. This upsets the functioning of entire system which results
in poor heat rejection and consequent higher consumption of energy. The cooling
treatment aspects and the potential problems are addressed in a separate course
titled "Cooling Water Treatment and Its Relevance
to Energy Conservation".
Cooling Towers: Facts & Checklist
A separate 2-hour
course deals with the advance knowledge, practical considerations and facts
about cooling towers. This includes the illustrations that clarify the common
misconceptions about cooling towers. The course is titled "Know
more about Cooling Towers- Facts and Realities"
Economic Evaluation of Projects
The cooling tower is one of the most expensive equipment in the plant. Any new
project or the projects requiring modification and renovation must perform the
total life cycle analysis before taking an appropriate decision. A 2-hour generic
reading titled "Six Ways to Perform Economic Evaluation
of Projects" is a recommended reading.
Once
you finish studying the
above course content,
you need to
take a quiz
to obtain the PDH credits.
DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDHonline.com or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered professional engineer. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.
