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EP-4477972-B1 - REFRIGERANT CHARGE METHOD

EP4477972B1EP 4477972 B1EP4477972 B1EP 4477972B1EP-4477972-B1

Inventors

  • TOYOOKA, TAKASHI

Dates

Publication Date
20260506
Application Date
20230201

Claims (13)

  1. A method for charging a refrigerant into a refrigeration circuit (100) that includes a compressor (1), a condenser (2), a throttle device (6), an evaporator (8), a first port (11), and a second port (12), the first port (11) being disposed in a high pressure portion of the compressor (1) or in a location downstream of the compressor (1) and upstream of the throttle device (6), the second port (12) being disposed in a low pressure portion of the compressor (1) or in a location upstream of the compressor (1) and downstream of the throttle device (6), the method comprising: connecting, to the first port (11), a mouth (22) of a container (20) in which the refrigerant is enclosed, the refrigerant including a high boiling point refrigerant (23) in a liquid state and a medium boiling point refrigerant (24) having a boiling point lower than that of the high boiling point refrigerant (23) and in a wet gas state; charging at least a portion of the refrigerant in the container (20) into the refrigeration circuit (100) through the first port (11) from the container (20), the container (20) being in a position such that the mouth (22) faces downward; and after charging the refrigerant in the container (20) into the refrigeration circuit (100) through the first port (11), charging at least a portion of the refrigerant remaining in the container (20) into the refrigeration circuit (100) through the second port (12) from the container (20), wherein at this time the position of the container (20) is such that the mouth (22) faces upward or downward.
  2. The method according to claim 1, further comprising: connecting the mouth (22) of the container (20), the first port (11), and the second port (12) to each other with a jig (30) that includes a branch pipe (32) and a path switching device (34, 34), wherein the charging the at least a portion of the refrigerant remaining in the container (20) into the refrigeration circuit (100) through the second port (12) is performed by switching a path with the path switching device (34, 34).
  3. The method according to claim 1 or 2, further comprising: determining the port to be used first for refrigerant charging from the container (20) by detecting a state of the refrigeration circuit (100) or a refrigeration apparatus including the refrigeration circuit (100); connecting the mouth (22) to the second port (12) in place of the first port (11) based on the detected state; and charging the at least a portion of the refrigerant in the container (20) into the refrigeration circuit (100) through the second port (12) from the container (20), the container (20) being in a position such that the mouth (22) faces upward.
  4. The method according to claim 3, further comprising: after charging the at least a portion of the refrigerant in the container (20) into the refrigeration circuit (100) through the second port (12), at least a portion of the refrigerant remaining in the container (20) is charged into the refrigeration circuit (100) through the second port (12) from the container (20) in the position such that the mouth (22) faces downward.
  5. The method according to claim 3 or 4, wherein: the detected state is a temperature of the refrigerant flowing from the throttle device (6) to the compressor (1); and when the temperature is higher than a predetermined value, the connecting the mouth (22) to the second port (12) in place of the first port (11) is performed.
  6. The method according to any one of claims 1 to 5, further comprising: by charging the at least a portion of the refrigerant remaining in the container (20) into the refrigeration circuit (100) through the second port (12), bringing at least a portion of the refrigerant charged through the second port (12) into contact with lubricating oil retained in the evaporator (8); reducing viscosity of the lubricating oil; and causing the lubricating oil to permeate through the refrigeration circuit (100).
  7. The method according to any one of claims 1 to 6, wherein a low boiling point refrigerant (25) having a boiling point lower than that of the medium boiling point refrigerant (24) and in a gas state is also enclosed in the container (20).
  8. The method according to claim 7, wherein in the container (20), 50 wt% or more and 80 wt% or less of the high boiling point refrigerant (23), 10 wt% or more and less than 50 wt% of the medium boiling point refrigerant (24), and 20 wt% or less of the low boiling point refrigerant (25) are enclosed.
  9. The method according to claim 7 or 8, wherein: the high boiling point refrigerant (23) is normal butane or isobutene; the medium boiling point refrigerant (24) is ethane, ethylene, or xenon; and the low boiling point refrigerant (25) is methane or krypton.
  10. The method according to claim 9, wherein: the high boiling point refrigerant (23) is normal butane; the medium boiling point refrigerant (24) is ethane; and the low boiling point refrigerant (25) is methane.
  11. The method according to any one of claims 1 to 10, wherein an oil carrier agent (26) to be charged into the refrigeration circuit (100) together with the refrigerant is also enclosed in the container (20).
  12. The method according to claim 11, wherein in the container (20), 0.14 wt% or more and 14 wt% or less of the oil carrier agent (26) is enclosed.
  13. The method according to claim 11 or 12, wherein the oil carrier agent (26) is normal pentane or propane.

Description

Technical Field The present invention relates to a method for charging a refrigerant (refrigerant charging method). Background Art Patent Literature (hereinafter, referred to as PTL) 1 discloses a method for filling a refrigerant circuit with a non-azeotropic refrigerant mixture by using a tank that contains the non-azeotropic refrigerant mixture at an amount that can be filled at one time. In this method, the refrigerant circuit is applied to an air conditioner, and R407C is used as the non-azeotropic refrigerant mixture. R407C is composed of HFC32 (boiling point: -51.7°C), HFC125 (boiling point: - 48.5°C), and HFC134a (boiling point: -26.5°C). The boiling points of these three refrigerants are relatively close to each other. Therefore, these three types of refrigerants are considered to be mixed relatively evenly in the tank at room temperature before being charged into the refrigerant circuit. JP H10 281 597 A relates to a refrigerant circuit which includes a compressor, a four-way changeover valve, an outdoor heat exchanger, an outdoor electronic expansion valve, a refrigerant filling valve, a liquid receiver , indoor electronic expansion valves, indoor heat exchangers, and an accumulator all connected in order. The refrigerant filling valve is connected with a refrigerant bomb in which a non-azeotropic mixture refrigerant is filled. A refrigerant circulating in the refrigerant circuit is reduced in pressure with the outdoor electronic expansion valve, and pressure of a refrigerant filling valve part is made smaller than the pressure in the refrigerant bomb. A liquid refrigerant in the refrigerant bomb flows into the refrigerant circuit with the aid of a pressure difference between the inside of the refrigerant bomb and the inside of a refrigerant filling part. JP H11 270933 A relates to a non azeotropic mixed refrigerant charge method for charging an air conditioner, which has a refrigerant circuit where a compressor, an outdoor heat exchanger, an electric expansion valve, and an indoor heat exchanger are arranged in order, with a non azeotropic mixed refrigerant in liquid form, a bomb charged with a non azeotropic mixed refrigerant is connected to a refrigerant pipe for coupling the compressor with the indoor heat exchanger through a three-way valve, and next the air conditioner is operated for cooling, and at this time, the electric expansion valve is adjusted to put it in overheat control operation, and then the refrigerant pipe for coupling the compressor and the indoor heat exchanger is charged with the nonazeotropic mixed refrigerant in liquid form through the three-way valve from the bomb. US 5 970 721 A relates to a method and an apparatus for injecting mixed refrigerant into a refrigerant circuit comprising at least a compressor, a condenser, an expansion device and an evaporator which are connected to one another through a refrigerant pipe, the mixed refrigerant is intermittently injected from a refrigerant bomb at a predetermined position of a low pressure side of the refrigerant circuit while keeping the mixed refrigerant in a liquid state. The intermittent injection operation (amount) of the liquid refrigerant into the refrigerant circuit may be controlled on the basis of the degree of superheat of the mixed refrigerant in the refrigerant circuit. JP H08 193762 A relates to a container filled with an adsorbent which is put in a high pressure container. A partition plate having an isolation film is provided to divide the inside of the container to two parts. Hereby, a mixing ratio itself of a liquid refrigerant in the container is changed when a remaining amount is reduced to make proper the composition of the taken-out refrigerant. Citation List Patent Literature PTL 1 Japanese Patent Application Laid-Open No. H08-200897 Summary of Invention Technical Problem For example, some non-azeotropic refrigerant mixtures are composed of a plurality of refrigerants having boiling points significantly different to each other, such as a non-azeotropic refrigerant mixture that is configured to fill a refrigeration circuit of an ultra-low temperature freezer that achieves an extremely low temperature of -80°C or less. These plurality of refrigerants may be in a state such that the refrigerants are separated from each another in a sealed container before being charged into the refrigeration circuit. There is a demand for a method for reliably charging a non-azeotropic refrigerant mixture in such a state into a refrigeration circuit. An object of the present invention is to provide a refrigerant charging method capable of reliably charging a non-azeotropic refrigerant mixture into a refrigeration circuit. Solution to Problem This object is solved by the present invention as recited in the appended independent claim. Particular embodiments of the present invention are the object of the appended dependent claims. Advantageous Effects of Invention The present disclosure can provide a refrigerant charging met