If your facility uses heavy machinery that generates heat, you need an industrial air-cooled and water-cooled chiller system to cool the processes and internal components of your machine. Understanding how an industrial chiller works and the different types of chillers available will help you make the right choice for your cooling needs.
What is a chiller?
Industrial chiller is a refrigeration system that is used to reduce the temperature of machines, industrial spaces and processing fluids by removing heat from the system and transferring it to another place. Industrial chillers are essential for temperature regulation in several industrial processes such as plastic injection machinery, metal plating, oil field production, and food processing.
Why use a chiller?
Industrial air-cooled and water-cooled chiller systems are useful for applications where suitable operating temperatures are required. When integrated with heat-sensitive processes, chillers prevent thermal damage to process equipment and ensure end products are not altered by exposure to inappropriate temperatures.
How air-cooled and water-cooled chillers work
Industrial chillers work based on the following principles of operation.
Phase change: When the liquid coolant is heated, the phase change turns into a gas, and when the gaseous coolant is supercooled, it turns back into a liquid.
Heat flow: Heat energy always flows from an area of higher concentration to an area of lower concentration.
Boiling point: A decrease in pressure on a liquid lowers its boiling point and an increase in pressure increases its boiling point.
How does the chiller work?
An industrial chiller system is guided by one of two operating principles:
Absorption chillers integrate heat exchangers that extract heat from any associated process and distribute it to the outside. Heat exchangers usually consist of tubes containing cooling fluids (air, water or a mixture of water and other fluids).
Vapor compression chillers achieve a cooling effect by circulating coolant in pipes through processes that require cooling. This draws heat from any associated process into the cooler, which is then transferred to a refrigerant system that cools the chiller fluid and prepares it for a new process cooling cycle.
Chillers consist of four essential components. An evaporator, a compressor, a condenser and an expansion unit. In addition, each chiller system contains a refrigerant.
The process starts with low pressure refrigerant entering the evaporator. Inside the evaporator, the chiller’s refrigerant is heated, causing it to turn into a gas. In the next step, the gas refrigerant enters the compressor, which increases its pressure.
Water-cooled and air-cooled industrial chillers
The high-pressure refrigerant goes to the condenser, which removes heat using cooling tower cooling water or ambient air and condenses it into a high-pressure liquid. The condensed refrigerant then goes to the expansion unit, which has a valve that acts as a metering device to limit the refrigerant flow.
As a result, it reduces the refrigerant pressure and restarts the cooling process. The entire process is known as the refrigeration cycle.
The main components of the chiller
Central chiller components include the following:
The function of the chiller condenser unit is to remove heat from the refrigerant that circulates in the chiller unit. This is achieved by circulating water between the cooling tower and the condenser for water-cooled types, or by blowing cool air over the condenser tubes for air-cooled chiller units.
The compressor is the driving unit of every chiller system. It creates the pressure gradient necessary to push the refrigerant around the chiller unit to achieve process cooling. A variety of condensers are available, the most popular of which are centrifugal, screw, and reciprocating compressors.
An evaporator is placed between the expansion valve and the condenser, removing heat from any process associated with the circulating refrigerant. It is then directed to a cooling tower or air-cooled, depending on the chiller configuration.
Thermal expansion valves
The thermal expansion valves, which are placed between the compressor and the evaporator, are used to expand the passing refrigerant. This action reduces pressure and improves heat removal from the evaporator.
Each chiller has a power unit that controls the electrical energy flowing through the system. Power unit components usually include starters, power monitoring panels, and circuit breakers.
Control panels serve to regulate the entire cooling operation process. They typically combine sensors, alarms, and displays that allow operators to adjust system settings for optimal thermal control.
These devices may be installed on the evaporator of the chiller system or its cooled water condenser. Their purpose is to effectively direct the flow of water.
All kinds of industrial chillers
The three main types of chillers in use today are: air-cooled chillers, water-cooled chillers, and absorption chillers. We will also briefly discuss cooling towers (an alternative or supplemental cooling system).
Industry cooling tower
Choosing the right chiller will help you save money, reduce downtime, and improve operational efficiency.
Cooled water chillers
Water-cooled chillers use water from an external cooling tower to remove heat from a gaseous refrigerant in the condenser before it changes phase to liquid.
Air cooled chillers
Instead of cooling water, air-cooled chillers use ambient air to remove heat from the refrigerant in the condenser.
Steam compressor chillers
This type of chiller uses refrigerant to cool fluids and processing spaces. A compressor is used as the driving force to pump the refrigerant around the system.
Vapor absorption chillers
Vapor absorption chillers do not have a single compressor. Instead, they use a heat source, e.g. Solar energy or heat dissipation to drive the coolant in the system.
How does an absorption chiller work?
The process starts with cooling the liquid in an evaporator, which turns it into a gas. Next, the gaseous coolant is absorbed by a concentrated adsorbent such as lithium bromide or ammonia supplied by a generator. Finally, the dilute solution absorbs the coolant while the heat is absorbed by the cooling water.
The dilute solution of coolant and absorbent flows through the heat exchanger to the generator and is heated there. The coolant evaporates from the solution, condenses and is sent out again to cool. The adsorbent, now concentrated, is also recycled.
Uses of water-cooled and air-cooled industrial chillers
injection molding machine chiller
Industrial chiller systems can be used for cooling operations in various industries. Below are some of the most common programs:
Food processing – Industrial chillers are widely used in food production and processing operations that require high precision in temperature control. For example, dairy plant chillers are used to control temperature during the process. Likewise, food industry chillers help with mixer cooling, potable water cooling, and jacketed yeast tank cooling, all of which are vital components of the food industry.
Plastic injection machines and blow molding machines- Injection molding is a mass production technique for creating plastic parts using a plastic injection machine. The process and the melt must be maintained within a precise temperature range to avoid problems such as cracking, warping and internal stresses in the final product. An injection chiller can provide a stream of supercooled liquid to cool the mold at an ideal rate to ensure optimal product quality.
Space cooling – In manufacturing plants that generate a lot of heat from the heavy machinery they use, a chiller can help prevent the temperature from rising in the work spaces. They also help save money on purchasing separate HVAC systems for cooling.
Buy the right chiller for your needs
A properly sized chiller is critical to efficient and cost-effective process, machinery, and space cooling. A simple chiller measurement tool can help you quickly determine the optimal chiller capacity, tonnage, and size.
Please contact our experts for technical advice on buying all kinds of industrial chillers and guidance.