Chiller
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A Chiller is a machine that produces chilled water (usually mixed with ~20% glycol and corrosion inhibitors) which is used to cool and dehumidify air in commercial and industrial facilities (see air conditioning). A typical chiller is rated between 15 to 1000 tons (180,000 to 12,000,000 BTU/h or 53 to 3,500 kW) in cooling power. There are basically four different types of chillers: Reciprocating, centrifugal, or screw-driven chillers are mechanical machines that can be powered by electric motors, steam, or gas turbines. Absorption chillers are powered by a heat source (such as steam or hot water). They have very low electrical power requirements - very rarely above 15 kW combined consumption for both the solution pump and the refrigerant pump.
Chilled water is then distributed to air handling units as a refrigerant. The air handling unit is a heat exchanger consisting basically of a fan, a filter bank, and heating/cooling coil, inlet/outlet chilled water port, and air inlet port. These air handling units provide air conditioning to the building by running the incomming warm air through the coil of chilled water, transferring the heat from the air to the chilled water, thus, cooling the air.
Chillers can be air-cooled or water-cooled. Water-cooled chillers incorporate the use of cooling towers which improve heat rejection more efficiently at the condenser than air-cooled chillers.
Industrial Chillers cool water using refrigeration cycles to provide a constant stream of coolant for manufacturing and laboratory processes. Industrial chillers use refrigeration to cool water that is then pumped through process or laboratory equipment. Industrial chillers are used in the controlled cooling of plastics during fabrication, manufacturing elements such as printer rollers, and high-heat specialized items such as MRI machines and lasers. Industrial chillers typically come as complete packaged closed-loop systems, including the chiller unit, condenser, and pump station with recirculating pump, expansion tank, no-flow shutdown, and temperature control.
Closed loop industrial chillers recirculate a clean coolant at a constant temperature and pressure to increase the stability and reproducibility of water-cooled machines and instruments. Open loop industrial chiller systems are also available. Open loop industrial chillers control the temperature of a liquid in an open tank or sump by constantly recirculating it. The liquid is drawn from the tank, pumped through the chiller and back to the tank. An adjustable thermostat senses the makeup liquid temperature, cycling the chiller to maintain a constant temperature in the tank. Most industrial chillers use refrigeration as the media for cooling, but some rely on simpler techniques such as air or water flowing over coils containing the coolant to regulate temperature. Water is the most commonly used coolant within process chillers, although coolant mixtures (mostly water with a coolant additive to enhance heat dissipation) are frequently employed. Industrial chillers are used for controlled cooling of products, mechanisms and factory machinery in a wide range of industries. They are often used in injection and blow molding, metal working cutting oils, welding equipment, die-casting and machine tooling, chemical processing, pharmaceutical formulation, food and beverage processing, lasers, vacuum systems, X-ray diffraction, power supplies and power generation stations, analytical equipment, semiconductors, compressed air and gas cooling.
Important specifications to consider when searching for industrial chillers include the power source, cooling capacity, fluid discharge temperature, and compressor motor horsepower. Process pump specifications that are important to consider include the process flow, process pressure, and pump rating. Other important specifications include the reservoir capacity full load amperage. Control panel features that should be considered when selecting between industrial chillers include the local control panel, remote control panel, temperature indicators, and pressure indicators. Additional features include emergency alarms, hot gas bypass, city water switchover, and casters. An important environmental parameter to consider is the operating temperature.
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