Industrial grade refrigerators need to achieve ultra-low temperature environments ranging from -40 ℃ to -86 ℃ or even lower, and traditional single-stage compression refrigeration technology is no longer effective. The bottleneck lies in the fact that excessive compression ratio can lead to high exhaust temperature, sharp decrease in efficiency, and shortened compressor life. At this point, cascade compression technology has become the core technology for achieving efficient and reliable ultra-low temperature refrigeration.

The core principle of the cascade compression system is to use two independent and collaborative refrigeration cycles: a high-temperature cycle (usually using medium temperature refrigerants such as R404A) and a low-temperature cycle (using low-temperature refrigerants such as R23 or R508B). The two cycles are connected by a component called the "evaporative condenser". The evaporator of the high-temperature cycle no longer absorbs heat into the box, but is used to condense the high-temperature and high-pressure gaseous refrigerant discharged from the compressor in the low-temperature cycle. In this way, the condensation temperature of the low-temperature cycle is reduced from the high ambient temperature (such as 30 ℃) to a very low negative value (such as -30 ℃), allowing its evaporator to easily create a low temperature of -80 ℃ inside the box.

This technology brings three key advantages:

Efficient and stable: Each compressor operates within its own suitable pressure and temperature range, with a reasonable compression ratio, high system operating efficiency, and stable reliability.

High reliability: significantly reduces the exhaust temperature and load of each level of compressor, significantly extending the service life of core components.

Wide temperature range: By scientifically combining different refrigerants, this technology can break through the limit of a single refrigerant and easily cover a wide ultra-low temperature range below -40 ℃.

Therefore, cascade compression technology is the cornerstone of industrial grade ultra-low temperature refrigerators. Through clever system design, it combines two simple cycles to solve the technical difficulties that single-stage compression cannot overcome, meeting the strict requirements of ultra-low temperature environments in scientific research, medical, industrial and other fields.