Cascade Refrigeration System

Cascade Refrigeration System

In the industrial refrigeration cycle system, low temperature can be obtained by adopting two-stage or multi-stage compression refrigeration cycle, which solves the problem of excessive pressure ratio. If the two-stage or multi-stage vapor compression refrigeration cycle cannot meet this requirement, we need to use the cascade refrigeration system. There are three main reasons why cascade refrigeration system must be adopted.

1. The result characteristics of piston compressor valves are limited: low evaporation pressure affects the automatic switching characteristics of reciprocating piston compressor valves, which deviates from the design range. When the suction pressure is 10~16kPa, the suction valve of the compressor does not open, and the compressor cannot suck. On the other hand, the compressor and the low-pressure part of the system operate under high vacuum, and the possibility of intrusion of non-condensable gas becomes high.

2. Limitation of refrigeration cycle pressure ratio: Once the necessary evaporation pressure is too low, even if the two-stage compression refrigeration cycle is used, the pressure ratio of each stage still exceeds the specified value, which greatly reduces the efficiency of the refrigeration cycle. In addition, with multi-stage compression, the cycle pressure is guaranteed, but the refrigeration system is complex and the technical and economic indicators are not high.

3. Restricted by the freezing point of the refrigerant: when the evaporation temperature required by the refrigeration cycle system of the chiller is lower than the freezing point of the refrigerant, the refrigerant freezes and cannot flow, and the system cannot circulate. For example, because the freezing point of R17 is -77.7°C, it is obviously not suitable for the refrigeration cycle system whose evaporation temperature is below -77.7°C.

Based on the above three points, it is unfavorable or impossible to use a single refrigerant multi-stage compression refrigeration cycle chiller to obtain a lower temperature. Although the evaporation temperature of the multi-stage compression refrigeration cycle is lower than that of the single-stage compression refrigeration cycle, it is limited by the physical properties of the refrigerant itself and the working characteristics of the compressor. When the evaporation temperature is lower, the multi-stage compression refrigeration cycle is used. Often can not meet the requirements, at this time, need to use cascade refrigeration system.

Customized Solutions For Your Business

Low Temperature Chillers (Water Cooled & Air Cooled)

Temperature Control Range: -150°C to -5°C

We specialize in the production of low-temperature chillers with a temperature control range as low as -150°C, which can meet the refrigeration needs of different industries.

Recirculating Chillers (Water Cooled & Air Cooled)

Temperature Control Range: -120°C to +30°C

Our recirculating chiller adopts low-temperature refrigeration technology, the temperature is as low as -120℃, and various accessories are customizable.

Room Temperature Chillers / Small Chillers

Temperature Control Range: +5°C to +50°C

The chiller can be widely used in various industries and laboratories, and supports customized design.

Direct Cooling Type Refrigeration Equipments

Temperature Control Range: -120°C to -10°C

It is suitable for places with small heat exchange area and large heat exchange.

Direct Cooling Ultra Low Temp Chillers

Temperature Control Range: -150°C to -110°C

Customized solutions for your business.

Screw Chillers

Low temperature screw chillers and room temperature screw chillers

Customized solutions for your business.