阅读说明：本技术 超低温跨临界复叠制冷系统及制冷方法 (Ultra-low temperature transcritical cascade refrigeration system and refrigeration method ) 是由 韩兴旺 于 2019-12-31 设计创作，主要内容包括：超低温跨临界复叠制冷系统及制冷方法。单工质多级压缩由于其局限性,一般用来制取-60℃以上的低温。近年来超低温制冷剂技术的需求量逐渐增加,对于-80℃以下的温度范围,传统的制冷方式是采用三级复叠制冷系统。本发明组成包括：该超低温跨临界复叠制冷系统及制冷方法包括以R404A作为循环工质的高温级循环系统和以R14作为循环工质的低温级循环系统。本发明用于超低温跨临界复叠制冷。(An ultra-low temperature transcritical cascade refrigeration system and a refrigeration method. Single working medium multi-stage compression is generally used for preparing low temperature above-60 ℃ due to the limitation thereof. In recent years, the demand of ultra-low temperature refrigerant technology is gradually increased, and for the temperature range below-80 ℃, a three-stage cascade refrigeration system is adopted in the traditional refrigeration mode. The invention comprises the following components: the ultra-low temperature transcritical cascade refrigeration system and the refrigeration method comprise a high-temperature-stage circulation system taking R404A as a circulation working medium and a low-temperature-stage circulation system taking R14 as a circulation working medium. The invention is used for ultralow temperature transcritical cascade refrigeration.)

1. An ultra-low temperature transcritical cascade refrigeration system is characterized in that: the ultra-low temperature transcritical cascade refrigeration system and the refrigeration method comprise a high-temperature-level circulation system taking R404A as a circulating working medium and a low-temperature-level circulation system taking R14 as the circulating working medium;

the high-temperature stage circulating system comprises an R404A compressor, wherein the outlet of the R404A compressor is connected with the inlet of an air-cooled condenser through a pipeline, the outlet of the air-cooled condenser is connected with the inlet of an R404A liquid storage device through a pipeline, the outlet of the R404A liquid storage device is connected with the inlet of an R404A electronic expansion valve through a pipeline, the outlet of an R404A electronic expansion valve is connected with the inlet of an evaporative condenser through a pipeline, the outlet of the evaporative condenser is connected with the inlet of an R404A gas-liquid separator through a pipeline, and the outlet of the R404A gas-liquid separator is connected with the inlet of the R404A compressor through a pipeline;

the low temperature stage circulation system include the R14 compressor, the export of R14 compressor and the entry of air-cooled condenser pass through the tube coupling, the export of air-cooled condenser and evaporative condenser's entry pass through the tube coupling, evaporative condenser's export and the entry of R14 reservoir pass through the tube coupling, the export of R14 reservoir and the entry of regenerator pass through the tube coupling, the export of regenerator and R14 electronic expansion valve entry pass through the tube coupling, the export of R14 electronic expansion valve and the entry of evaporator pass through the tube coupling, the entry of evaporator export and regenerator opposite side pass through the tube coupling, the export of regenerator opposite side and gas-liquid separator's entry pass through the tube coupling, the export of R14 gas-liquid separator with the entry of R14 compressor pass through the tube coupling.

2. The ultra-low temperature transcritical cascade refrigeration system as claimed in claim 1, wherein: the R14 compressor is a high pressure-bearing compressor.

3. The ultra-low temperature transcritical cascade refrigeration system as claimed in claim 2, wherein: the air-cooled condenser is a double-system air-cooled condenser.

4. A method of refrigerating the ultra-low temperature transcritical cascade refrigeration system as claimed in claims 1-3, characterized by: the method comprises the following steps:

the part of the R404A used as the circulating working medium is compressed by an R404A compressor and then enters an air-cooled condenser to exchange heat with air, the heat-released R404A is condensed into high-pressure liquid and enters an R404A liquid storage device, the liquid enters an evaporative condenser through an electronic expansion valve to be evaporated into low-temperature R14 condensation to provide cold energy, and the heat-absorbed R404A returns to an air return port of the compressor through an R404A gas-liquid separator to complete circulation;

the part of R14 as the cycle working medium belongs to transcritical cycle, R14 compressor compresses R14 low pressure gas, the gas enters an air-cooled condenser to exchange heat with air and be cooled, the gas enters an evaporative condenser to exchange heat with R404A, high temperature and high pressure R14 gas is condensed, the condensed R14 enters a heat regenerator through a liquid storage device, after being supercooled in the heat regenerator, the gas enters a tail end evaporator through an electronic expansion valve to provide cold energy for the tail end, and the heat absorbed R14 gas enters an air return port of the R14 compressor through an R14 gas-liquid separator after the heat regenerator is overheated to complete the cycle.

The technical field is as follows:

the invention relates to an ultra-low temperature transcritical cascade refrigeration system and a refrigeration method.

Background art:

single working medium multi-stage compression is generally used for preparing low temperature above-60 ℃ due to the limitation thereof. In recent years, the demand of ultra-low temperature refrigerant technology is gradually increased, and for the temperature range below-80 ℃, a three-stage cascade refrigeration system is adopted in the traditional refrigeration mode.

The invention content is as follows:

the present invention is to solve the above problems, and an object of the present invention is to provide an ultra-low temperature transcritical refrigeration system and a refrigeration method in which an ultra-low temperature refrigerant R14 and a medium-low temperature refrigerant R404A are stacked.

The above purpose is realized by the following technical scheme:

an ultra-low temperature transcritical cascade refrigeration system comprises a high-temperature stage circulation system taking R404A as a circulation working medium and a low-temperature stage circulation system taking R14 as the circulation working medium;

the high-temperature stage circulating system comprises an R404A compressor, wherein the outlet of the R404A compressor is connected with the inlet of an air-cooled condenser through a pipeline, the outlet of the air-cooled condenser is connected with the inlet of an R404A liquid storage device through a pipeline, the outlet of the R404A liquid storage device is connected with the inlet of an R404A electronic expansion valve through a pipeline, the outlet of an R404A electronic expansion valve is connected with the inlet of an evaporative condenser through a pipeline, the outlet of the evaporative condenser is connected with the inlet of an R404A gas-liquid separator through a pipeline, and the outlet of the R404A gas-liquid separator is connected with the inlet of the R404A compressor through a pipeline;

the low temperature stage circulation system include the R14 compressor, the export of R14 compressor and the entry of air-cooled condenser pass through the tube coupling, the export of air-cooled condenser and evaporative condenser's entry pass through the tube coupling, evaporative condenser's export and the entry of R14 reservoir pass through the tube coupling, the export of R14 reservoir and the entry of regenerator pass through the tube coupling, the export of regenerator and R14 electronic expansion valve entry pass through the tube coupling, the export of R14 electronic expansion valve and the entry of evaporator pass through the tube coupling, the entry of evaporator export and regenerator opposite side pass through the tube coupling, the export of regenerator opposite side and gas-liquid separator's entry pass through the tube coupling, the export of R14 gas-liquid separator with the entry of R14 compressor pass through the tube coupling.

In the ultra-low temperature transcritical cascade refrigeration system, the R14 compressor is a high pressure-bearing compressor.

The ultra-low temperature transcritical cascade refrigeration system is characterized in that the air-cooled condenser is a dual-system air-cooled condenser.

A refrigeration method of an ultra-low temperature transcritical cascade refrigeration system comprises the following steps:

the part of the R404A used as the circulating working medium is compressed by an R404A compressor and then enters an air-cooled condenser to exchange heat with air, the heat-released R404A is condensed into high-pressure liquid and enters an R404A liquid storage device, the liquid enters an evaporative condenser through an electronic expansion valve to be evaporated into low-temperature R14 condensation to provide cold energy, and the heat-absorbed R404A returns to an air return port of the compressor through an R404A gas-liquid separator to complete circulation;

the part of R14 as the cycle working medium belongs to transcritical cycle, R14 compressor compresses R14 low pressure gas, the gas enters an air-cooled condenser to exchange heat with air and be cooled, the gas enters an evaporative condenser to exchange heat with R404A, high temperature and high pressure R14 gas is condensed, the condensed R14 enters a heat regenerator through a liquid storage device, after being supercooled in the heat regenerator, the gas enters a tail end evaporator through an electronic expansion valve to provide cold energy for the tail end, and the heat absorbed R14 gas enters an air return port of the R14 compressor through an R14 gas-liquid separator after the heat regenerator is overheated to complete the cycle.

Has the advantages that:

1. the ultra-low temperature transcritical refrigerating system adopts the principle of a cascade refrigerating system, but the circulation of the R14 part belongs to the transcritical circulation process, a high-pressure-bearing compressor is adopted, and the R14 is in a high-exhaust-pressure running state. And the air-cooled condenser in the system is of a double-system structure, and can reduce the temperature by respectively using the outdoor air as the exhaust air of R14 and the exhaust air of R404A. The regenerator in the system provides subcooling for the R14 liquid, improving the refrigeration efficiency of the system. The ultralow temperature refrigeration system with the lowest evaporation temperature of-110 ℃ can be obtained by two-stage overlapping.

The refrigerant adopted by the invention has no damage to the ozone layer, and the ozone layer damage potential value is 0. Among them, R14 is a colorless, odorless, tasteless, nonflammable gas, and is one of the most stable organic compounds.

The air-cooled condenser selected by the invention is a dual-system air-cooled condenser, and can reduce the temperature by respectively exhausting R14 and R404A with outdoor air.

In the invention, the heat regenerator is added in the circulation process of R14 to improve the supercooling degree of R14 liquid and the superheat degree of R14 return air, thereby improving the refrigeration efficiency of the system.

Description of the drawings:

FIG. 1 is a schematic diagram of the present invention;

in the figure: 1. R404A compressor; 2. an air-cooled condenser; 3. R404A reservoir; 4. R404A electronic expansion valve; 5. an evaporative condenser; 6. R404A gas-liquid separator; 7. a R14 compressor; 8. a reservoir of R14; 9. A heat regenerator; 10. r14 electronic expansion valve; 11. an evaporator; 12. r14 gas-liquid separator.

The specific implementation mode is as follows: