Water chiller

Chillers, some manufacturers also called water- chiller or process- cool, serve primarily to cool a fluid. This is used as a heat transfer medium and has the task of absorbing heat to a heat source and to remove them. Frequently one is water use, which is set as a function of temperature for frost protection with ethylene glycol and corrosion inhibitors.

Function and structure

The heat transfer medium circulates in its own circuit. Powered by a pump, it assumes a source of heat thermal energy and dispenses it through a heat exchanger (English evaporator " evaporator " ) to the chiller. This fluid circuit is separated by the operating in countercurrent evaporator hydraulically from the refrigerant circuit. The actual " cooling " is based on the principle of left -speed Carnot cycle process and is realized by a compression refrigeration system with said refrigeration circuit. Basis for the Carnot cycle is the second law of thermodynamics by Rudolf Clausius: "Heat always flows only from a system of higher temperature to a system of lower temperature, but never vice versa, unless using energy. "

If we look at this law on the example of the chiller, it can be described as follows:

The heat transfer in the heat exchanger is concluded by the temperature difference between the evaporation temperature of a liquid (known as refrigerant) in the refrigeration cycle and the return temperature of the fluid. The refrigerant evaporates at a relatively low temperature (for example, t0 = 5 ° C) and low pressure. Is necessary for the evaporation, heat energy is removed from the heat transfer medium, whereby the temperature is lowered to, for example, tW2 = 10 ° C. It is thus " produces cold " no, but deprived of heat.

A refrigerant compressor draws the evaporated gaseous refrigerant and compresses it, by supplying energy. In the condenser, the heat absorbed by the evaporator is below condensing pressure and condensing temperature (eg: tC = 50 ° C ) to the environment (eg: tV = 32 ° C ) cast. By the heat, the refrigerant condenses and passes into the liquid state. The cycle closes on the following built-in throttle valve through which the refrigerant flows back into the evaporator.

Application

The advantage of chillers is to separate from the heat source installation. About hoses or pipes connected, must not be interfered with in the refrigerant circuit during assembly.

Are used chillers where it comes to cool water, oils or emulsions. This rule tolerances are below 1 Kelvin prior art. Various applications can be found in medical magnetic resonance and computed tomography in. In these plants, the waste heat of solenoids and other electrical components must be dissipated through the chiller. In industry, heat loads occur, for example in machine tools manufacturing technology for master forming, forming, cutting, joining and coating. For example, the beam quality of a laser beam for sheet metal processing is critical of temperature constancy dependent.

Chillers are also used for air conditioning of buildings. For this purpose, an air -water heat exchanger in the respective rooms or a common air -water heat exchanger is in addition to the chiller necessary.

• Refrigeration technology