One-grade self-overlaying low-temperature refrigeration circulating system using double-stage gas-liquid separator

Abstract

The invention proposes a one-grade self-overlaying low-temperature refrigeration circulating system using a double-stage gas-liquid separator. The system comprises a compressor and a condenser connected with an inlet of a first-grade gas-liquid separator in sequence; a saturated liquid refrigerant, rich in a high-boiling point working medium, generated by the first-grade gas-liquid separator enters a second-grade gas-liquid separator by a throttle valve to separate to obtain saturated gas and liquid; and a saturated gas working medium generated by the first-grade gas-liquid separator is mixed with the gas obtained by the second-grade gas-liquid separator by the throttle valve to enter an evaporation condenser to cool as supercooled liquid, flows into an evaporator to absorb heat to change to the saturated gas after being throttled by the throttle valve, is mixed with a working medium rich in a high-boiling point component from the second-grade gas-liquid separator to enter a condensation evaporator to absorb heat to change to superheated gas, and finally enters the compressor to realize complete self-overlapping refrigeration circulation. The system adopts two grades of serially connected gas-liquid separators to further purify a low-boiling point working medium for refrigeration, promotes the gas sucking pressure of the compressor, increases the flow of the evaporator working medium, and effectively improves the performance of a low-temperature refrigeration system.

Description

technical field [0001] The invention belongs to the refrigeration technical field of refrigerators and freezers, and in particular relates to a one-stage self-cascading low-temperature refrigeration cycle system using a two-stage gas-liquid separator. Background technique [0002] In recent years, with the continuous advancement of science and technology, medical treatment, food industry, refrigeration and many other fields have put forward a more urgent demand for lower operating temperature, especially for the low temperature environment below -40 ℃. . At present, low-temperature refrigeration can be realized through multi-stage compression cycle, mixed working fluid throttling cycle and self-cascading cycle. [0003] Self-cascading refrigeration technology uses the separation characteristics of non-azeotropic working fluid components to realize automatic cascade through evaporative condensers, which can realize multi-stage cascade with a single compressor, and then obtai...

AI Technical Summary

Problems solved by technology

However, due to the low-temperature performance requirements of the system, the compressor suction pressure is low and the pressure ratio is large, resulting in low system performance, so the application development of this technology is limited

The main reason is that the low-boiling point components cannot be effectively separated as refrigeration fluid, and the presence of high-boiling point components in the refrigeration fluid greatly reduces the evaporation pressure, resulting in an increase in the compressor pressure ratio and a decrease in performance

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