Two-stage carbon dioxide low-temp. refrigerator

Abstract

The two-stage CO2 low-temp. refrigerating equipment is characterized by that its low-temp. jet pump is connected with gas-liquid-solid three-phase separator, the gas-liquid-solid three-phase separator is respectively connected with heat regenerator, circulating pump and user's heat exchanger. The outlet state of the low-temp. jet pump is three-phase point of CO2, and the fluid of outlet is a gas-liquid-solid three-phase coexisting mixture, said low-temp. jet pump can be made into monounit together with gas-liquid-solid three-phase separator, so that it can make the solid microparticle diameter of CO2 formed after isenthalpic decompression of liquid separated from intermediate gas-liquid be very small, the circulating pump can be used for transferring solid-liquid two-phase mixture into user's heat exchanger, and can utilize the crilical hidden heat produced by converting CO2 solid-phase micropartide into liquid phase to release cold quantity.

Description

1. Technical field [0001] The invention relates to a low-temperature refrigeration device, in particular to a two-stage carbon dioxide low-temperature refrigeration device. 2. Background technology [0002] The current serious global environmental problems, such as the destruction of the atmospheric ozone layer and the greenhouse effect, have had a profound impact on compression refrigeration technology. The prohibition of CFCs refrigerants and the gradual replacement of HCFC refrigerants have made the application of HFC refrigerants more and more extensive. Completely solving the environmental problems caused by synthetic refrigerants makes natural working fluids more and more people's attention, and its application range is also expanding. Natural working fluids such as carbon dioxide, NH 3 And refrigerants such as hydrocarbons do not damage the ozone layer and have no greenhouse effect. Therefore, air-conditioning carbon dioxide transcritical refrigeration systems, NH ...

AI Technical Summary

Problems solved by technology

especially NH 3 / CO 2 The two-stage low-temperature refrigeration system uses carbon dioxide as the secondary refrigerant. Compared with single-phase refrigerants, it has high heat transfer performance, and the viscosity of the liquid is one or two orders of magnitude lower. Moreover, the mass flow rate of carbon dioxide is very small, and the pipe diameter is small. It can better solve the problem of high pressure in the carbon dioxide secondary refrigerant cycle, but the disadvantage of this system is that the low temperature obtained by the system is generally above -40°C, which cannot meet the low temperature requirements below -50°C in some occasions

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