Advantages and disadvantages of various chillers

Advantages and disadvantages of various chillers

The selection of all chiller units should be based on the scale of the project and objective conditions, and the advantages and disadvantages are only relative, one thousandIt is obviously not suitable for you to use a centrifuge in a square meter house. In the south where there are not many heat resources, choosing an absorption air conditioning unit as the host is also a strange thing.

1、 Piston type chiller unit

Advantages:
　　1.The material is simple, can be made of general metal materials, easy to process, and has low cost;
　　2.The system device is simple, easy to lubricate, and does not require an exhaust system;
　　3.By using multiple machine heads and high-speed multi cylinder engines, performance can be improved.
Disadvantages:
　　1.There are many components, vulnerable parts, complex and frequent repairs, and high repair costs;
　　2.Low compression ratio, small cooling capacity per unit;
　　3.Poor adjustment performance under partial load of single machine head, cylinder unloading adjustment, unable to achieve stepless adjustment;
　　4.Belonging to reciprocating motion with significant vibration;
　　5.The weight index of unit cooling capacity is relatively high.

2、 Screw type chiller unit

Advantages:

　　1.Simple structure, few moving parts, few vulnerable parts, only piston type1/10Low failure rate and long lifespan;
　　2.Smooth circular motion, no issues during low load operation“surge”Phenomenon, low noise, small vibration;
　　3.The compression ratio can reach up to20，EERHigh value;
　　4.Easy to adjust, can be used in10%~100%Stepless adjustment within the range, high efficiency under partial load, significant power saving;
　　5.Small in size and light in weight, it can be used as a fully enclosed large capacity unit;
　　6.Not sensitive to wet stroke;
　　7.It belongs to positive pressure operation and there is no problem of external air intrusion corrosion.
Disadvantages:
　　1.The price is higher than that of piston type;
　　2.The single machine capacity is smaller than that of centrifugal type, and the speed is lower than that of centrifugal type;
　　3.The lubricating oil system is complex and consumes a lot of fuel;
　　4.The noise of large capacity units is higher than that of centrifugal units;
　　5.High machining accuracy and assembly accuracy are required.

3、 Centrifugal chiller unit

Advantages:

　　1.High impeller 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 weight index of unit cooling capacity is small;
　　4.The refrigerant does not contain lubricating oil, and the heat transfer performance of the evaporator and condenser is good;
　　5.EERHigh value, theoretical value can reach6.99；
　　6.Easy to adjust, in10%~100%Internally adjustable infinitely.
Disadvantages:
　　1.Single stage compressors may experience issues at low loads“surge”Phenomenon, stable operation at full load;
　　2.Strict requirements for material strength, processing accuracy, and manufacturing quality;
　　3.When the operating conditions deviate from the design conditions, the efficiency decreases rapidly, and the cooling capacity decreases more rapidly with the decrease of evaporation temperature than the piston
Fast formula;
　　4.Centrifugal negative pressure system is prone to external air infiltration, which poses a risk of chemical changes and corrosion of pipelines.

4、 Modular chiller unit

Advantages:

　　1.It is an improved version of piston and screw type, which is composed of multiple cold water units combined;
　　2.The unit has a small volume, light weight, low height, and small footprint;
　　3.Easy installation, no need to reserve installation holes, convenient on-site assembly, especially suitable for renovation projects.
Disadvantages:
　　1.The price is relatively expensive;
　　2.The number of modules should generally not exceed8Taiwan

5、 Water source heat pump unit

Advantages:
　　1.Save energy and recover heat during winter operation;
　　2.Derived from nature;
　　3.The energy efficiency ratio is relatively high;
　　4.Easy installation and low maintenance costs;
　　5.Flexible application and easy adjustment.
Disadvantages:
　　1.During the transition season, it is not advisable to maximize the use of fresh air;
　　2.The noise level of the crew is relatively high

6、 Lithium bromide absorption chiller (steam, hot water, and direct fired)

Advantages:

　　1.Less moving parts, low failure rate, smooth movement, low vibration, and low noise;
　　2.Simple processing, easy operation, and can achieve10%~100%Stepless adjustment;
　　3.Lithium bromide solution is non-toxic and has no destructive effect on the ozone layer;
　　4.Waste heat can be utilized. Waste heat and other low-grade thermal energy;
　　5.Low operating costs and good safety;
　　6.Powered by thermal energy, it consumes less electricity.
Disadvantages:
　　1.The service life is shorter than that of compression type;
　　2.Energy saving is not energy-saving, with high steam consumption and low thermal efficiency;
　　3.The unit operates under vacuum for a long time, and external air is prone to invade. If air invades, it will cause a decrease in cooling capacity, so strict requirements are required;
Sealing brings inconvenience to manufacturing and use;
　　4.The heat dissipation load of the unit is higher than that of the compression type, which requires higher quality of cooling water;
　　5.Lithium bromide solution has strong corrosiveness to carbon steel, affecting the service life and performance of the unit