Chiller

Chiller units, also known as refrigerators, chilled water units, refrigeration units, ice water units, cooling equipment, etc., are commonly seen in air - conditioning systems and industrial cooling systems, such as in the fields of laboratory equipment, chemical product manufacturing, pharmaceutical production, food processing, and beverage processing.

Different specific operating conditions require different chiller units.

A chiller unit mainly realizes the state change of the flowing working fluid within the unit through four main components: compressor, evaporator, condenser, and expansion valve, thus achieving the effects of refrigeration and heating.

According to the different compressors used, chiller units include screw chiller units, scroll chiller units, centrifugal chiller units, and piston chiller units.

For example, common types are "water - cooled screw units", "centrifugal heat pump units", "screw heat - recovery units", "screw low - temperature refrigeration units", etc., as well as modular chiller units composed of multiple chiller units.

Based on different controlled temperatures, chiller units can be divided into low - temperature industrial chillers and normal - temperature chillers. The temperature of normal - temperature units is generally controlled within the range of 0℃ - 35℃. The temperature of low - temperature units is generally controlled around 0℃ - - 100℃. Industrial chillers can be classified into the following categories according to the water outlet temperature: water outlet temperature: - 25℃ - - 5℃; water outlet temperature: - 25℃ - - 45℃; water outlet temperature: below - 45℃.

According to different refrigeration forms, chiller units can generally be divided into water - cooled and air - cooled types. Water - cooled chiller units can be further divided into water - cooled chiller units, water - cooled brine chiller units, and water - cooled ethylene glycol chiller units according to different refrigerants. In daily use, many people simply call it a water - cooled unit.

A water - cooled chiller unit dissipates heat through water. That is, it uses a shell - and - tube evaporator to exchange heat between water and the refrigerant. After the refrigerant system absorbs the heat load in the water, cools the water to produce chilled water, and then through the action of the refrigeration compressor, the heat is carried to the shell - and - tube condenser. Heat exchange occurs between the refrigerant and water, and the water absorbs the heat and then takes the heat out through the water pipe to the external cooling tower for dissipation.

An air - cooled chiller unit uses a fin - type condenser, and the fan forces air to flow to take away the heat of the refrigerant. Compared with the components of a water - cooled chiller unit, it omits the cooling tower, cooling water pump, and cooling pipeline system, and has certain installation advantages. Air - cooled chiller units are suitable for use in water - scarce areas or mobile occasions, especially for small chiller units with low cooling capacity requirements.

In addition, in areas with poor water quality, using a water - cooled chiller unit is likely to cause problems such as condenser scaling and water pipe blockage. However, for the fin - type condenser used in air - cooled chiller units, if too much dust accumulates on the surface, it will greatly affect the heat - exchange efficiency. Therefore, a dust - filter screen must be installed in front of the heat - dissipation fins of the air - cooled chiller unit, and it needs to be cleaned regularly.

In terms of energy efficiency, the cooling capacity of a water - cooled chiller unit is 300 - 500 kcal/h higher than that of an air - cooled chiller unit. In GB19577 "Minimum Allowable Values of Energy Efficiency and Energy Efficiency Grades for Chiller Units", the energy - efficiency grades of chiller units are specified. The manufacturer should indicate the rated energy - efficiency grade of the chiller unit in its product's factory - out documents.