Method of charging a refrigeration system and apparatus therefor

Claim 3

The method of adding refrigerant, to an operating undercharged refrigeration system of claim 1 wherein the amount of said incremental quantity is proportional to the difference between the determined and preselected system superheat conditions.

Claim 4

The method of adding refrigerant to an operating undercharged refrigeration system of claim 1 wherein the measurement of said temperatures is converted into electrical signals which are stored and utilized in said condition comparing step.

Claim 5

The method of adding refrigerant to an operating undercharged refrigeration system of claim 1 wherein the saturated vapor temperature is determined by utilizing a sample of liquid refrigerant taken from said system.

Claim 6

The method of adding refrigerant to an operating undercharged refrigeration system of claim 1 wherein the saturated vapor temperature is determined by utilizing a sample of liquid refrigeraant taken from said system, said vaporized sample being subsequently returned as refrigerant vapor to the system.

Claim 7

The method of adding refrigerant to an operating undercharged refrigeration system of claim 1 wherein means defining a chamber are caused to have a temperature corresponding to said suction gas temperature and said measuring of the suction gas temperature is effected by measuring the temperature of said chamber means.

Claim 8

The method of adding refrigerant to an operating undercharged refrigeration system of claim 1 wherein means defining a chamber are caused to have a temperature corresponding to said suction gas temperature and said measuring of the suction gas is effected by measuring the temperature of said chamber means, said saturated vapor temperature determination being effected by vaporizing in said chamber a sample of liquid refrigerant taken from said system and then measuring the temperature of said chamber means.

Claim 9

In a refrigerating system including a compressor, a condenser, a evaporator, a liquid line and first expansion means connecting the evaporator with the condenser, and a suction line connecting said evaporator with said compressor and having a suction port for introducing refrigerant into said suction line, a refrigerant charging apparatus comprising: an expansion chamber mounted in mass heat transfer association with said suction line and having an outlet connected to said suction port; means for sensing the temperature of said expansion chamber; means for supplying liquid refrigerant to said expansion chamber from said liquid line including first valve means and second expansion means; means for supplying additional refrigerant to said system including a source of pressurized refrigerant and second valve means; and a control circuit connected to said temperature sensing means and said first and second valve means; said control circuit having means adapted to be preset for a preselected system superheat condition, said temperature sensing means being arranged to determine the actual system superheat condition by first sensing the suction line temperature and then saturated vapor temperature as a quantity of refrigerant is admitted to said chamber by said first valve means under control of said circuit, said circuit being arranged to be subsequently operable to open said second valve means in the event the determined system superheat exceeds the preselected superheat condition thereby to add a quantity of refrigerant from said source to said suction line through said suction port.

Claim 10

In a refrigerating system including a compressor, a condenser, a evaporator, a liquid line and first expansion means connecting the evaporator with the condenser, and a suction line connecting said evaporator with said compressor and having a suction port for introducing refrigerant into said suction line, a refrigerant charging apparatus comprising: an expansion chamber mounted in mass heat transfer association with said suction line and having an outlet connected to said suction port; means for sensing the temperature of said expansion chamber; means for supplying liquid refrigerant to said expansion chamber from said liquid line including first valve means and second expansion means; means for supplying additional refrigerant to said system including a source of pressurized refrigerant and second valve means; and a control circuit connected to said temperature sensing means and said first and second valve means; said control circuit having means adapted to be preset for a preselected system superheat condition, said temperature sensing means being arranged to determine the actual system superheat condition by first sensing the suction line temperature and then saturated vapor temperature as a quantity of refrigerant is admitted to said chamber by said first valve means under control of said circuit, said circuit being arranged to be subsequently operable to open said second valve means in the event the determined system superheat exceeds the preselected superheat condition thereby to add a quantity of refrigerant from said source to said suction line through said suction port.

Claim 11

The refrigeration system charging apparatus for claim 8 wherein said temperature sensing means comprises a circuit including a thermistor.

Claim 12

The refrigeration system charging apparatus of claim 8 wherein said circuit is arranged to open said second valve means for a period of time proportional to the amount that the determined superheat exceeds the preselected superheat.

Claim 13

The refrigeration system charging apparatus of claim 8 wherein said circuit is arranged to open said second valve means to add a quantity of refrigerant to said system and subsequently determine the system superheat condition seriatim repeatedly until the determined system superheat condition substantially equals to the preselected superheat condition.

Claim 14

In a refrigeration system having an evaporator, means for supplying liquid refrigerant to said evaporator for vaporization therein, and means for delivering refrigerant vapor from the evaporator, means for charging the refrigeration system comprising: sensing means for determining the difference between the temperature of the refrigerant vapor and the saturation temperature of the refrigerant in the system; refrigerant adding means responsive to the determined difference between said temperatures to add an incremental quantity of refrigerant to the system; and control means causing seriatim a repetition of the determination of said temperature difference and addition of refrigerant until said temperature difference is substantially equal to a preselected temperature difference corresponding to a desired superheat condition of the refrigeration system.

Claim 15

In a refrigeration system having an evaporator, means for supplying liquid refrigerant to said evaporator for vaporization therein, and means for delivering refrigerant vapor from the evaporator, means for charging the refrigeration system comprising: sensing means for determining the difference between the temperature of the refrigerant vapor and the saturation temperature of the refrigerant in the system; refrigerant adding means responsive to the determined difference between said temperatures to add an incremental quantity of refrigerant to the system; and control means causing seriatim a repetition of the determination of said temperature difference and addition of refrigerant until said temperature difference is substantially equal to a preselected temperature difference corresponding to a desired superheat condition of the refrigeration system.

Claim 16

The refrigeration system charging apparatus of claim 12 wherein said refrigerant adding means delivers the refrigerant to said means for delivering refrigerant from the evaporator.

Claim 17

The refrigeration system charging apparatus of claim 12 wherein the sensing means includes controlled valve means for sampling a portion of the liquid refrigerant from the liquid supplying means.

Claim 18

The refrigeration system charging apparatus of claim 12 wherein the sensing means inculdes first controlled valve means for sampling a portion of the liquid refrigerant from the liquid supplying means, and the refrigerant adding means includes a supply of refrigerant under pressure and a second controlled valve means for controlling delivery of the refrigerant from said supply to said system.

Claim 19

The refrigeration system charging apparatus of claim 12 wherein the sensing means includes first controlled valve means for sampling a portion of the liquid refrigerant from the liquid supplying means, the refrigerant adding means includes a supply of refrigerant under pressure and a second controlled valve means for controlling delivery of the refrigerant from said supply to said system, and said control means includes means for causing seriatim a. determination of the temperature of the refrigeration vapor, b. operation of said first controlled valve means to provide a sample of the liquid refrigerant, c. determination of the saturation temperature of said sample, and d. operation of said second controlled valve means to add an incremental quantity of refrigerant to the system in the event the determined difference between said temperatures is greater than said preselected temperature difference.

Claim 20

The refrigeration system charging apparatus of claim 12 wherein said control means defines means for causing the amount of said incremental quantity added to the system to be a direct function of said determined temperature difference.

Claim 21

The refrigeration system charging apparatus of claim 12 wherein the sensing means includes first controlled valve means for sampling a portion of the liquid refrigerant from the liquid supplying means, the refrigerant adding means includes a supply of refrigerant under pressure and a second controlled valve means for controlling delivery of the refrigerant from said supply to said system, said control means includes means for causing seriatim a. determination of the temperature of the refrigeration vapor, b. operation of said first controlled valve means to provide a sample of the liquid refrigerant, c. determination of the saturation temperature of said sample, and d. operation of said second controlled valve means to add an incremental quantity of refrigerant to the system in the event the determined difference between said temperatures is greater than said preselected temperature difference,

Claim 22

The refrigerant system charging apparatus of claim 12 wherein said sensing means comprises a circuit portion including a thermistor, a capacitor, and a resistor electrically connected to determine said temperature difference.