The Modern Industrial Chiller is basically a cooling system that removes heat from one element (water/glycol/air) and deposits into another (ambient air or water). The standard design is a system that cools 60° F water (water/glycol, or air) to 50° F and deposits the heat into the ambient air at 95° F (or water at 85° F).
This chilling technology is used by various industries to cool down the process machinery and the process using a freon chiller to cool a medium like air or water. To learn more about chillers in general and to help you make an informed decision about your own cooling problem, we are going to begin with a definition of a chiller and then move on to learning what a chiller can do for you, how to buy a chiller and what to look for when buying a chiller.
What Is A Chiller?
A chiller is a machine that removes heat from a liquid via a vapor-compression or absorption refrigeration cycle. This liquid can then be circulated through a heat exchanger to cool equipment, or another process stream (such as air or process water). As a necessary by-product, refrigeration creates waste heat that must be exhausted to ambience, or for greater efficiency, recovered for heating purposes.Chillers may use hermetic scroll, or semi hermetic screw, or centrifugal compressors.
Chilled water is used to cool and dehumidify air in mid- to large-size commercial, industrial, and institutional facilities. Water chillers can be water-cooled, air-cooled, or evaporatively cooled. Water-cooled systems can provide efficiency and environmental impact advantages over air-cooled systems.
How does a Chiller Work?
In most process cooling applications, a pumping system circulates cool water or a water/glycol solution from the chiller to the process. This cool fluid removes heat from the process and the warm fluid returns to the chiller. The process water is the means by which heat transfers from the process to the chiller.
Process chillers contain a chemical compound, called a refrigerant. There are many types of refrigerant and applications depending on the temperatures required but they all work on the basic principle of compression and phase-change of the refrigerant from a liquid to a gas and back to a liquid. This process of heating and cooling the refrigerant and changing it from a gas to a liquid and back again is the refrigeration cycle.
The refrigeration cycle starts with a low-pressure liquid/gas mix entering the evaporator. In the evaporator, heat from the process water or water/glycol solution boils the refrigerant, which changes it from a low-pressure liquid to a low-pressure gas. The low-pressure gas enters the compressor where it is compressed to high-pressure gas. The high-pressure gas enters the condenser where ambient air or condenser water removes heat to cool it to a high-pressure liquid. The high-pressure liquid travels to the expansion valve, which controls how much liquid refrigerant enters the evaporator, thereby beginning the refrigeration cycle again.
There are two types of condensers used in chillers; air-cooled and water-cooled. An air-cooled condenser uses ambient air to cool and condense the hot refrigerant gas back down to a liquid. It can be located inside the chiller or can be remotely located outside, but ultimately it rejects the heat from the chiller to the air. In a water-cooled condenser, water from a cooling tower cools and condenses the refrigerant.
Applications: What Can A Chiller Be Used For?
As one can imagine chillers are extremely important in the industrial world where there are literally millions of machines that generate a lot of heat. If these machine are to last any time at all, they need to be cooled. This is where chillers come in. A chiller can be used to cool any machine or process that operates at 60° F or lower. A cooling tower can be used to cool any machine or process that operates at 85° F or higher. Some of the more common applications are listed below:
In the plastics industry, a chilling system cools the hot plastic that is injected, blown, extruded or stamped. A chilling system can also cool down the equipment that is used to create plastic products (hydraulics of the molding machine, gear box and barrel of the extruder) that saves on energy and on the wear and tear of the machine itself. Plastics, Injection Molding
In the printing industry, a chiller not only removes the heat generated by the friction of the printing rollers, but cools down the paper after it comes out of the ink drying ovens in the process. Printing
In the laser cutting industry, light projection industry, etc. a chilling system is used to cool down the lasers and power supplies. Laser
In the rubber industry to cool the multizone water temperature control units of the rubber extruder barrel, cool the rubber mill, calendars and bambury mixers. Rubber
In the beverage industry, a chiller removes the heat gained from the process during mixing, cooking, or after pasteurizing the product. Beverage
If you use high tech equipment for magnetic resonance imaging, scanning, blood cooling and laboratory testing, you’ll need a cooling system to remove all the heat generated. MRI
With cooling expenses accounting for 30% to 50% of your total energy costs and rising fast, and the impending phaseout of chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) refrigerants, there is a rapidly growing need to replace large commercial air conditioning and refrigeration systems with a modular chilling system. Hvac