A kind of ultra-low temperature refrigeration method

Abstract

The invention discloses an ultra-low temperature refrigeration method for an ultra-low temperature refrigeration single cooling split type air conditioner. The cooling-only split air conditioner includes an evaporator, a compressor, a condenser, an electronic expansion valve for bypass, a capillary for pressure division, and a liquid storage tank. When the outdoor temperature is higher than 15°C, the system circulation pressure of the refrigerant cycle on the condensing side is maintained by adjusting the fan speed of the outdoor condenser; , the superheated steam refrigerant discharged from the compressor is bypassed directly before the liquid storage tank, and mixed with the low-temperature liquid refrigerant that has been heat-exchanged by the outdoor condenser to become a high-temperature two-phase refrigerant. The invention reduces the heat exchange intensity in the condenser tube in a continuously adjustable way to maintain the system circulation pressure on the condensation side, thereby maintaining the normal refrigerant circulation of the refrigeration system and achieving normal refrigeration under the condition of ultra-low outdoor ambient temperature .

Description

technical field [0001] The invention relates to a refrigeration method, in particular to an ultra-low temperature refrigeration method. Background technique [0002] In some usage scenarios, regardless of the outdoor temperature (50°C high or -40°C low), the indoor environment needs to be refrigerated. [0003] At present, there are mainly two processing schemes for low-temperature refrigeration in the market. [0004] 1. Maintain the system circulation pressure on the condensing side by reducing the heat transfer intensity outside the condenser tube, so as to maintain the normal refrigerant circulation of the refrigeration system, and achieve normal refrigeration under the ultra-low outdoor ambient temperature. That is: reduce the intensity of outdoor heat exchange by reducing the speed of the outdoor fan. [0005] However, there are defects in this solution: 1. Due to the characteristics of the motor, the speed of the outdoor fan cannot be reduced without limit; 2. When ...

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Problems solved by technology

[0005] However, there are defects in this solution: 1. Due to the characteristics of the motor, the speed of the outdoor fan cannot be reduced without limit; 2. When the speed of the outdoor fan is low, the wind pressure of the fan is small, and the heat exchange on the condensation side in different wind directions outdoors There is a large difference in strength; 3. When the outdoor fan is 0, there is a safety risk of high pressure and overpressure; 4. The minimum outdoor ambient temperature of this scheme is generally -15~-5℃

[0007] However, there are defects in this scheme: 1. Since the heat exchange intensity in the condenser tube is adjusted by the electromagnetic valve switch to maintain the system circulation pressure on the condensation side, there are pressure fluctuations in the refrigeration system, and the load of the compressor and the cooling capacity obtained in the room also fluctuate accordingly ; 2. This scheme is mainly used in refrigeration and refrigeration systems; 3. This scheme is suitable for the refrigeration system of fixed-speed machines, and there is a defect that the flow rate of the variable frequency compressor is too large

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