As with all chiller systems, screw chillers consist of an evaporator, expansion valve, refrigerant, internal piping and controls. Their compressor is the main point of difference in screw chillers, which use two helical rotors to drive and compress the refrigerant gas. This type of chiller has an almost constant flow performance and is powered by an electric motor, steam or gas turbine. They range in capacity from 25 to 800 tonnes and are effective when used with liquids with higher evaporation temperatures.
The screw or helical compressor in a screw chiller consists of two matching helical slotted rotors: a convex flap and a concave groove. They are housed in a fixed casing and move simultaneously. As they rotate, the refrigerant gas is compressed through the direct volume reduction between the two rotors and is converted into vapour.
These compressors are equipped with sliders that regulate the length of the compression path. Suction, compression and discharge all occur in a linear direction. The oil lubricant on the rotor also acts as a sealant. Motor cooling occurs when the refrigerant flows through the holes in the screw, which works as a liquid separator. The right size of screw cooler is very important.
When they are too large, they have a long reverse cycle time and will shut down if cooling is not required. This can also happen if the motor is running at a high, unnecessary speed or if it is open circuit driven. However, if configured correctly, electric chillers are reliable and efficient liquid chillers for the whole range of industrial and air conditioning applications.
1. The unit adopts a semi-closed screw compressor. The compressor adopts a 5:6 asymmetric high-efficiency screw rotor, which is graded or steplessly energy regulated. It is automatically adjusted according to load changes and is more energy efficient.
2. The unit heat exchanger adopts high-efficiency heat exchange tube to improve the cooling efficiency. At the same time, in order to reduce the lubricating oil entering the heat exchanger, the unit increases the secondary oil content, minimizes the amount of oil entering the heat exchanger, and passes the specially designed ejector. The oil return device directs the lubricating oil in the heat exchanger back to the compressor to improve the refrigeration efficiency of the unit and also improve the reliability of the unit operation.
3. The unit is equipped with multiple protections to make the unit operate safely and reliably. The unit adopts a direct cooling mode, which reduces the loss caused by the intermediate heat exchange and greatly reduces the running cost.
4. Environmentally friendly 134a refrigerant is used to improve unit operating efficiency. The unit is equipped with multiple protections to make the unit safe and reliable.
The series water cooled screw chiller used the efficient screw compressor from European, with its own superiority: high energy efficiency, low noise, high reliability, small footprint, easy installation, simple operation and high flexibility. It is widely used in surface engineering, medicine, chemical industry, metallurgy, leather, laser, electronics, plastic injection moulding, printing and other industries. The series of water chillers have too many models. It can achieve a perfect match for industrial applications.