Varied concentration mixed working medium auto-cascade refrigerator

Abstract

The invention discloses a varied concentration mixed working medium auto-cascade refrigerator, comprising four parts of a normal concentration loop, a first varied concentration loop, a second varied concentration loop and a third varied concentration loop; the normal concentration loop is provided with a compressor, a condenser, a rectifying device, a regenerator, a first throttling element, an evaporator, a second throttling element and a gas-liquid separator which are connected in turn, wherein the first varied concentration loop is provided with a third disconnecting valve 13, a liquid storage tank 9 and a fourth disconnecting valve 14 which are connected in turn; the second varied concentration loop is provided with a first disconnecting valve 11, a gas holder 7 and a second disconnecting valve 12 which are connected in turn; and the third varied concentration loop is provided with a fifth disconnecting valve 15, a gas holder 8 and a sixth disconnecting valve which are connected in turn. The invention dramatically improves the dynamic operation characteristics of the refrigerator at the stage to start lowering temperature, and can realize lower refrigerating temperature and improving thermal dynamic efficiency of the refrigerator. The invention is particularly applicable to the occasions not only needing rapid temperature reduction, but also needing lower refrigerating temperature, thus having favorable application prospect.

Description

technical field [0001] The invention belongs to the field of mixed working medium refrigeration, in particular to a variable concentration mixed working medium self-cascading refrigerator. Background technique [0002] The cooling temperature zone of the mixed working medium refrigerator can connect the general cold temperature zone and the deep cold temperature zone. In the field of general refrigeration, the vapor compression refrigerator utilizing the Joule-Thomson effect occupies a dominant position; in the low-temperature field, the Linde cycle and self-cascading refrigeration cycle utilizing the Joule-Thomson effect have also been widely used. Due to the high operating pressure of the Linde cycle system using a simple working fluid, the thermal efficiency of the system is low. Therefore, there is no competitive advantage in occasions where long-term use and high system efficiency requirements are required, and the application of mixed working fluid can solve this prob...

AI Technical Summary

Problems solved by technology

Although these refrigerators achieve a relatively low refrigeration temperature, there is usually such a problem: when the refrigeration target temperature is relatively low, due to the need to use a multi-component mixed refrigerant with a low boiling point and a high concentration, the mixed refrigerant will The proportion of the gas phase passing through the throttling element is too large and the flow rate is too small, so that the discharge pressure of the compressor is too high and the suction pressure is too low, which will cause the pressure ratio and discharge temperature of the compressor to be too high, and the life of the compressor will be shortened. It will greatly reduce or even cause the compressor to fail to start due to pressure protection

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