Automatic cascade type refrigerating and circulating system with unfixedly proportioned hybrid medium

Abstract

The invention relates to an automatic layered refrigeration cycle system with mixed working substance and without fixed proportion. It comprises a throttle element (5) connecting the evaporation condenser (4), and a throttle element (7) connecting the evaporator (9). It is characterized in that: said throttle element (5) is an automatic expansion valve whose stable over-cold degree is 0 to -20Deg. C; and the throttle element (7) is an automatic expansion valve whose stable over-heat degree is 9-20Deg. C. The invention can overcome the defects of present technique which need fixed proportion. And it uses aforementioned automatic expansion valves as throttle elements; therefore, it can adjust the liquid supply automatically according to the outlet over-heat (over-cold) degree of evaporator and evaporation condenser when the mixed working substance is in unfixed proportion, to avoid the lack of liquid supple or the reflux of compressor to confirm the normal operation of said refrigeration cycle system. The invention can be used in large refrigeration systems.

Description

Technical field: [0001] The invention relates to an automatic cascade refrigeration cycle system, in particular to an automatic cascade refrigeration cycle system which does not require a fixed ratio of mixed working fluids. Background technique: [0002] The known automatic cascade refrigeration cycle system is provided with a compressor, and a decondenser is connected with the exhaust port of the compressor. The vapor outlet of the separator is directly connected to the evaporative condenser, the liquid outlet is connected to the evaporative condenser through a throttling element, the vapor outlet of the evaporative condenser is connected to the suction port of the compressor, and the liquid outlet passes through the liquid receiver 1. The throttling element is connected with the evaporator, and the outlet of the evaporator is connected with the suction port of the compressor. The automatic cascade refrigeration cycle system needs to be filled with two kinds of refrigeran...

AI Technical Summary

Problems solved by technology

[0003] However, since the current separation technology cannot guarantee that the two refrigerants can be completely separated, the refrigerant with low purity will produce a temperature glide when evaporating at a fixed pressure, that is, the evaporation temperature of the high-temperature component will decrease, and the evaporation temperature of the low-temperature component will decrease. rise, and its temperature difference is larger

For this reason, the existing throttling element applied to single (pure) refrigerant - the automatic expansion valve with a static superheat of 2-8°C cannot be used in the automatic cascade refrigeration cycle system, otherwise it will cause liquid supply Insufficient or compressor liquid return and other phenomena, so that the existing automatic cascade refrigeration cycle system has the following disadvantages:

[0004] The mixed working fluid must have a fixed ratio. For example, if R13 / R12 is used as the mixed working fluid, the ratio must be 0.247:0.753 (Reference 1). When the refrigerant in the refrigeration cycle system leaks (such as system repair, valve replacement parts, etc.), its ratio will change, which will directly lead to changes in system parameters, and the refrigerator will not work normally or efficiently

At this time, all the remaining refrigerant in the system must be released, and then the mixed refrigerant prepared in proportion by the manufacturer must be added again, which will not only cause a lot of waste of refrigerant, but also cause pollution to the environment

[0005] In view of the above problems in the existing automatic cascade refrigeration cycle system, its application range is limited, especially it is difficult to apply in large and medium-sized refrigeration devices such as tuna quick-freezing and refrigeration, so that the existing tuna quick-freezing and refrigeration can only use volume Two-stage compression refrigeration system with large size, high energy consumption, low efficiency and poor economy

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