Mixed refrigerant adapted for refrigerating temperature range of minus 90 DEG C centigrade to minus 100 DEG C centigrade

Abstract

The invention provides a mixed refrigerant suitable for the freezing zone at 90 to 100 below zero DEG C, which is made by mixing the ethane and the ethylene. The mol percentage is as follows: ethane 20 to 80 percent and ethylene 20 to 80 percent. The mixed refrigerant adopts the preparation that the two components are physically mixed according to a set matching at normal temperature and the corresponding mixed refrigerant can be obtained. The ODP is zero and the mineral lubricating oil of compressor can be well inter-dissolve with the mixed refrigerant . The mixed refrigerant is suitable for the low temperature grade of two-grade cascade refrigeration system and can form 90 to 100 DEG C below zero ultralow temperature.

Description

technical field [0001] The invention belongs to the field of refrigeration systems and relates to a refrigerant, in particular to a mixed refrigerant suitable for the refrigeration temperature range of -90°C to -100°C. Background technique [0002] With the development of society and science and technology, especially in the past two years, there are more equipment with two-stage cascade refrigeration temperature at -70°C to -86°C, but the equipment with refrigeration temperature at -90°C to -100°C is less its rare. The basic principle of two-stage cascading is to use a high-temperature stage refrigeration system, and its evaporator is used to cool the condenser of the low-temperature stage refrigeration system, so that the condensation pressure of the low-temperature stage can reach a reasonable level (1.0-1.5MPa), so as to obtain a lower cooling temperature. Each stage is an independent refrigeration cycle. Generally, high-temperature grades generally use R401, R404A, R...

AI Technical Summary

Problems solved by technology

In practice, the high-temperature stage evaporator is often above -40°C with load, and there is a temperature difference of 3-5°C during the heat exchange process, and the condensation pressure of the low-temperature stage far exceeds 1.45MPa, so the compression ratio of the compressor often If it is required to reach 14 or more, the usual low-temperature compressors will not be able to bear it.

Therefore, in the case of using a two-stage cascade system and an ordinary low-temperature compressor, it is difficult to find a refrigerant with an evaporation temperature between -90°C and -100°C among the existing conventional low-temperature refrigerants

To reach this temperature range, it is necessary to achieve it through a three-stage refrigeration system, an automatic cascade refrigeration system or other methods, and the cost will increase significantly

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