Pressure regulation system of ultra-low temperature refrigerating device

Abstract

The invention discloses a pressure adjusting system for an ultralow-temperature refrigerator, which is characterized in that the system is composed of a balance tank (3), a pressure controller (6), solenoids (1, 5), and throttling elements (2, 4), wherein the balance tank (3) is connected with the high-pressure end and the low-pressure end of a compressor through the solenoids (1, 5) and the throttling elements (2, 4); and the pressure controller (6) is arranged on the high-pressure portion of a refrigerating system. The pressure adjusting system for an ultralow-temperature refrigerator formed according to the above scheme can reduce the ratio of low-boiling-point work medium participating in the circulation on the initial operation stage of the refrigerating system, and gradually increase the circulation amount of the low-boiling point work medium along the decrease of the system temperature, thus achieving continuous temperature decrease. On one hand, the system can prevent the occurrence of compressor fault due to overhigh pressure and, on the other hand, can keep the compressor in a stable operation condition, thus achieving uniform temperature decrease speed and stable operation.

Description

technical field [0001] The invention relates to a refrigerating device, more specifically a pressure regulating system of an ultra-low temperature refrigerating machine. Background technique [0002] Ultra-low temperature freezers generally refer to freezers with a refrigeration temperature range of -40°C to -86°C or even lower. It is the basic equipment that hospitals, disease control centers, blood banks, universities and scientific research institutions must be equipped with. It is mainly used to preserve organs, tissues, skin, red blood cells, lymphocytes, DNA, embryos, bone marrow, seeds, pollen, specimens, etc. and other materials for low temperature tests. Two-stage or multi-stage vapor compression refrigeration cycle and compound vapor compression refrigerator system are commonly used in cryogenic refrigeration. Two-stage or multi-stage vapor compression refrigeration cycles use a single working fluid, each refrigeration cycle requires a compressor, and there are c...

AI Technical Summary

Problems solved by technology

For the temperature range above -86°C, due to the low proportion of low-boiling point working fluid, the filling pressure is not high. After auxiliary measures such as balance tanks, the starting pressure of the compressor will not be very high, but it must reach -120°C or lower. In the area, due to the increase in the proportion of low-boiling point working fluid, the filling pressure is very high, and it is difficult to achieve the expected effect after auxiliary measures such as balance tanks

When the compressor is just started, a large amount of low-boiling point working fluid accumulates in the condenser in the form of non-condensable gas. The pressure of the high-pressure part is too high, and the compressor is protected, causing the system to not work normally.

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