Five commonly used chillers in industry

1、 Screw chiller unit
The chiller is designed with a screw compressor as the main unit. The screw chiller technology is mature in industry and is widely used in chemical, pharmaceutical, food, refrigeration, engineering construction, etc. The typical refrigeration capacity range is 700 to 1000kW.

The characteristics of screw chillers include:

1）Simple structure, fewer moving parts, fewer vulnerable parts, and long service life.
2）The circular motion is stable, and there is no "wheezing" phenomenon during low load operation.
3）High compression ratio and high EER value.
4）It can be continuously adjusted within the range of 10% to 100%, with high efficiency and significant power savings under partial loads.
5）Not sensitive to wet stroke.

2、 Piston chiller unit
Compared to screw chillers and piston chillers, the compressor of the piston chiller adopts a piston motion mode and is assembled from a refrigeration compressor, condenser, evaporator, thermal expansion valve, etc. The characteristics of the piston chiller are:

1）Wide applicable pressure range and strong maintainability.
2）By adopting multiple heads and high-speed multi cylinders, the performance can be improved.
3）The material is simple, suitable for general metal materials, easy to process, and low in cost.
4）The chiller system is relatively simple, and mobile installation is fast.
The commonly used cooling range is 1-10 horsepower.

3、 Modular chiller
A modular chiller unit consists of multiple modular chiller units combined in parallel, with two completely independent refrigeration systems, each with a dual or single speed compressor, evaporator, condenser, and controller. There is a computer monitoring system inside, which controls the entire unit and regularly starts and stops each compressor according to the size of the air conditioning load, or changes high-speed operation to low-speed operation.

The characteristics of modular chillers include:
1）Adjust the number of operating modules according to changes in cooling load, to achieve optimal coordination between output cooling capacity and air conditioning load, and reduce energy consumption.
2）Multiple compressors working in parallel are guaranteed.
3）Lightweight, small in size, saving construction area.
4）The modular combination provides maximum backup capacity for the refrigeration system, and expanding the unit capacity is very simple and feasible.

4、 Centrifugal chiller unit
But its working principle is fundamentally different from piston compressors. It does not increase the pressure of the steam body by reducing the cylinder volume, but by relying on changes in kinetic energy to increase the pressure of the steam body.
The characteristics of centrifugal chillers include:

1) The impeller has high rotational speed, large gas transmission capacity, and large single machine capacity.
2) Less vulnerable parts, reliable operation, compact structure, smooth operation, low vibration, and low noise.
3) The quality index of unit refrigeration capacity is small.
4) There is no lubricating oil mixed in the refrigerant, and the heat transfer performance of the evaporator and condenser is good.
5) The EER value is high and can be infinitely adjusted within 10% to 100%.

5、 Water source heat pump unit
It uses water circulating in shared pipelines, water extracted from wells, lakes, or rivers, or water circulating in underground coils as a cold (hot) source to produce cold (hot) air or cold (hot) water equipment; Including a side heat exchange device, compressor, and heat source side heat exchange device, with single refrigeration or refrigeration and heating functions.

The characteristics of water source heat pump units:
1) Energy saving, can recover heat during winter operation.
2) Multiple operations for one machine, stable operation.
3) The equipment occupies a small area and has significant environmental effects.
4) High energy efficiency ratio.

Source: Kedley chiller