Cooling towers remove the heat from the discharged water from a condenser. The discharged water is either discharged into the environment or recycled back into the plant to cool the system. Whereas, Chillers absorb heat from coolant and transfers to the air around the chiller unit.
The function of both cooling towers and chillers are quite similar, yet what varies is their types and components used and the nature of the equipment they cool and operate.
Types of cooling towers
There are primarily two types of cooling tower and they are classified based on the type of airflow into the cooling tower.
Mechanical draft cooling towers:
Mechanical cooling towers mostly rely on power-driven fans for drawing the air through the tower. Even mechanical draft cooling towers are subdivided into two types, they are: induced draft cooling tower and forced draft cooling tower.
Natural draft cooling towers:
Natural draft cooling towers work with the help of the chimney operation of the cooling tower. The airflow of natural draft cooling towers is caused by the temperature difference between the air present inside and outside the cooling tower. These are industrial cooling towers, usually seen at a nuclear power plant.
Types of chillers
Chillers are created as coolers that are either air-cooled or water-cooled.
Air-cooled chillers:
Before condensation and recirculation, air-cooled chillers make use of ambient air for rejection of heat from the refrigerant in the condenser. Attached fans help speed up the cooling process.
Water-cooled chillers:
Most water-cooled chillers cool the gaseous refrigeration in the condenser by using water from an external tower. The refrigerant undergoes a phase change into a liquid after expelling its heat and then gets recirculated into the system.
Main Components
Cooling towers: The pumps and the pools are the major components of cooling towers. Pumps supply water to the cooling towers and generate a stream of water to assist the process of cooling in the system. Water discharged from the circulating water system gets collected in the distribution basin.
Chillers: The major components of cooler/chillers are compressors, evaporator heat exchangers, and condenser heat exchangers. The condenser heat exchanger plays a vital role to disperse the heat from the radiator to the air.
Power consumption efficiency
Cooling towers: Water pumps are the major components of operating cooling towers. These pumps use a lot of energy. Additionally, the fans used in cooling towers also use up electrical energy. The cooling towers offer higher cooling capacity which results in the higher energy efficiency of the cooling.
Chillers: Chillers are not quite as energy-efficient as compared to cooling towers since they are powered by compressors and heat exchangers. When it comes to comparing the refrigerators, water-cooled refrigerators are best suited for they offer optimal efficiency when compared to energy consumption. This happens because a wet surface transfers heat more efficiently than a dry surface. Consequently, water-cooled chillers require 10% less energy than air-cooled chillers.
Applications and uses
Cooling towers: Cooling towers are generally used in large scale cooling operations. They provide cooled water to electrical power generation, oil and gas refining, thermal power stations, and other mechanical processes. Cooling towers are also used by power plants that are located near rivers and lakes to cool the circulating water that has been heated in the condenser.
Chillers: The most familiar chiller applications comprise use in the plastic industry and refrigeration application. They are generally used in applications that are unaffected by the extra heat discharged by it. As a matter of fact, warming the plant during the winter uses the additional heat.
The importance of Cooling towers installation
Cooling towers being the heat rejecting devices allow the majority of the water that is being used to be recycled. This results in avoiding an enormous amount of water wastage. They even maximize chiller efficiency and ensures longer overall system life.
Cooling towers just like other HVAC units require proper maintenance, in order to ensure they are running at peak efficiency. Ensure that you regularly inspect your cooling towers after installation.
