Many regions of the world are grappling with water scarcity. Numerous efforts in desalination and water trading attest to the magnitude of the problem. The World Bank puts the number of people living in absolute water scarcity at 2 billion, a figure that could reach the 4.6 billion mark within the next 65 years. The water-energy nexus has been a regular theme in recent years. The power plants that supply most countries with electricity consume large amounts of water, either directly or indirectly. When it comes to feasibility studies for cooling plants, the debate on whether or not to use water is very important. Based on the results of this study, the choice will be between water-cooled or air-cooled chillers.
This device removes heat from the load and transfers it to the environment using a refrigeration system. This heat transfer unit is the chiller of choice for large facilities such as power plants. It is simply a system of vinyl + water or reservoir and circulation components. The coolant is circulated from the tank to the equipment subcooling. There are also air-cooled chillers that will disperse with a heat fan. These are newer and common in power plants.
Water-cooled chiller systems have cooling towers, so they are more efficient than air-cooled chillers. Water-cooled chillers are more efficient because their condensation depends on the ambient temperature bulb temperature, which is lower than the ambient dry bulb temperature. The lower the chiller condensation, the higher the efficiency. The system has several basic components, including
Charge water pumps
TES water reservoir
Some users may prefer these chillers because they take up a smaller footprint compared to air-cooled chillers. These chillers also offer higher efficiency and a longer service life than the alternatives mentioned above. Those who wish to keep their equipment indoors may find water chillers to be desirable.
The role of the evaporator is to produce chilled water. The unit releases the water at a temperature of about 6°C (42.8°F) and pushes it throughout the facility with the help of a pump. A network of pipes carries the chilled water through each necessary part of the building. After exchanging cool air with room air blowing through the air handling unit (AHU) and fan coil unit (FCU), the water now has a temperature of about 12°C (53.6°F). It returns to the evaporator, where the refrigerant absorbs the excess heat and directs it to the condenser. The chilled water is cooled again and can now continue to cool the facility. Note that this is always referred to as "chilled water", regardless of temperature.
Box Type Water Cooled Scroll Chiller
The refrigerant brings unwanted heat from the evaporator and passes through the condenser. There is another circuit connected to the condenser - the condenser water circuit, which is located between the cooling tower and the condenser. After entering the condenser at approximately 27°C (80.6°F), the water leaves at 32°C (89.6°F) and flows to the cooling tower. Please note that the refrigerant and the condenser should not be in direct contact at any time. Heat exchange is only through the tube walls. The condensate with excess heat enters the cooling tower for further heat dissipation.
This is where the excess heat ends up in the facility. A large fan supplies air to the facility. The air meets the oncoming condensate. Through direct contact, the condensate dissipates heat to the air. The condenser water returns to the condenser and the cycle continues. These open units come in a variety of designs depending on many factors. Examples include cross-flow, counter-flow, natural ventilation and mechanical ventilation. Join us in covering these designs in an upcoming post. This is a good way to address the confusion between cooling towers and chillers. However, if you still need more detailed information about water-cooled chiller components and operation, contact our team and you will be helped.