Comparison of advantages and disadvantages of 5 commonly used chillers
2018-12-26
01 Piston type chiller Advantage: 1. The material is simple, the general metal material can be used, the processing is easy, and the cost is low; 2. The system device is simple, easy to lubricate, and does not require an exhaust device; 3. With multi-head, high-speed multi-cylinder, performance can be improved. Disadvantages: 1. Many parts, more wearing parts, complicated maintenance, frequent, high maintenance costs; 2. The compression ratio is low, and the cooling capacity of the single machine is small; 3. The adjustment performance of the single head part under partial load is poor, the cylinder is adjusted, and it cannot be adjusted steplessly; 4. It is a reciprocating movement up and down, and the vibration is large 5. The rated cooling capacity has a large weight index. 02 Screw type chiller Advantage: 1. Simple structure, less moving parts, less wearing parts.(only 10 percent of the piston type), low failure rate and long service life; 2. The circular motion is stable, there is no "surge" phenomenon during low load operation, low noise and low vibration; 3. The compression ratio can be as high as 20 and the EER value is high; 4. It is convenient to adjust, can be steplessly adjusted within the range of 10%~100%, high efficiency at partial load, and significant power saving; 5. Small size and light weight, it can be made as a stand type fully enclosed large capacity unit; 6. Not sensitive to wet strokes; 7. It is a positive pressure operation, and there is no problem of intrusion of outside air. Disadvantages: 1. The price is higher than the piston type; 2. The capacity of single unit is smaller than the centrifugal type, and the rotation speed is lower than the centrifugal type; 3. The lubricating oil system is more complicated and consumes a lot of fuel; 4. Large-capacity unit noise is higher than centrifugal type; 5. Requires high machining accuracy and assembly accuracy. 03 Centrifugal chiller Advantage: 1. The impeller has high speed, large gas transmission volume and single machine has large capacity; 2. Less wearing parts, reliable work, compact structure, stable operation, low vibration and low noise; 3. The unit cooling capacity weight index is small; 4. The lubricating oil is not mixed in the refrigerant, and the heat transfer performance of the evaporator and the condenser is good; 5. The EER value is high, and the theoretical value can reach 6.99. 6. Easy to adjust, stepless adjustment within 10%~100%. Disadvantages: 1. The single-stage compressor will have a "surge" phenomenon at low load, but run smoothly at full load; 2. Strict requirements for material strength, processing accuracy and manufacturing quality; 3. When the operating condition deviates from the design working condition, the efficiency decreases rapidly, and the cooling capacity decreases with the evaporation temperature and decreases faster than the piston type; 4. Centrifugal negative pressure system, the outside air is easy to invade, there is a danger ...
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