US5050389A — Refrigeration system with oiless compressor suppo…

Claim 1

Independent Claim 233 words

A refrigeration system having a compressor rotor rotatably supported by a plurality of hydrodynamic bearings lubricated by oiless pressurized liquid refrigerant and pressurizing refrigerant which flows to a condenser providing liquid refrigerant which flows to an evaporator in fluid communication with the condenser and the compressor comprising: a refrigerant circuit, coupled to the compressor, for providing pressurized liquid refrigerant to the hydrodynamic bearings from the compressor and to the evaporator; a bearing pump, coupled to the refrigerant circuit and to the condenser, for providing pressurized refrigerant to the refrigerant circuit; a first temperature sensor sensing a temperature Tsink of a heat exchange fluid at the condenser and providing a temperature signal representative of the temperature Tsink of the heat exchange fluid at the condenser; a second temperature sensor sensing a temperature Tsource of a heat exchange fluid at the evaporator and providing a temperature Tsource signal representative of the temperature of the heat exchange fluid at the evaporator; and a controller, coupled to the temperature sensors, for controlling activation of the compressor, and bearing pump as a function of the temperature signals representative of Tsink and Tsource to provide for three modes of operation with the first mode of operation being activation of only the compressor, the second mode of operation being activation of the bearing pump and the compressor and the third mode of operation being activation of only the bearing pump.

Claim 2

Dependent Claim 233 words

A refrigeration system having a compressor rotor rotatably supported by a plurality of hydrodynamic bearings lubricated by oiless pressurized liquid refrigerant and pressurizing refrigerant which flows to a condenser providing liquid refrigerant which flows to an evaporator in fluid communication with the condenser and the compressor comprising: a refrigerant circuit, coupled to the compressor, for providing pressurized liquid refrigerant to the hydrodynamic bearings from the compressor and to the evaporator; a bearing pump, coupled to the refrigerant circuit and to the condenser, for providing pressurized refrigerant to the refrigerant circuit; a first temperature sensor sensing a temperature Tsink of a heat exchange fluid at the condenser and providing a temperature signal representative of the temperature Tsink of the heat exchange fluid at the condenser; a second temperature sensor sensing a temperature Tsource of a heat exchange fluid at the evaporator and providing a temperature Tsource signal representative of the temperature of the heat exchange fluid at the evaporator; and a controller, coupled to the temperature sensors, for controlling activation of the compressor, and bearing pump as a function of the temperature signals representative of Tsink and Tsource to provide for three modes of operation with the first mode of operation being activation of only the compressor, the second mode of operation being activation of the bearing pump and the compressor and the third mode of operation being activation of only the bearing pump.

Claim 3

Dependent Claim 23 words

A refrigeration system in accordance with claim 1 wherein: the first mode of operation occurs when (Tsource-Tsink)<TDiFF1 with TDiFF1 being a temperature difference.

Claim 4

Dependent Claim 31 words

A refrigeration system in accordance with claim 1 wherein: the second mode of operation occurs when TDiFF1≦(Tsource-Tsink)<TDiFF2 with TDiFF1 being a first temperature difference and TDiFF2 being a second temperature difference.

Claim 5

Dependent Claim 23 words

A refrigeration system in accordance with claim 1 wherein: the third mode of operation occurs when (Tsource-Tsink)≧TDiFF2 with TDiFF2 by a temperature difference.

Claim 6

Dependent Claim 49 words

A refrigeration system in accordance with claim 1 wherein: the first mode of operation occurs when (Tsource-Tsink )<TDiFF1; the second mode of operation occurs when TDiFF1≦(Tsource-Tsink)<TDiFF2; and the third mode of operation occurs when (Tsource-Tsink)≧TDiFF2; and TDiFF1 is a first temperature difference and TDiFF2 is a second temperature difference.

Claim 7

Dependent Claim 203 words

A refrigeration system having a compressor rotor rotatably supported by a plurality of hydrodynamic bearings lubricated by oiless pressurized liquid refrigerant and pressurizing refrigerant which flows to a condenser providing liquid refrigerant which flows to an evaporator in fluid communication with the condenser and the compressor comprising: a refrigerant circuit, coupled to the compressor, for providing pressurized liquid refrigerant to the hydrodynamic bearings from the compressor and to the evaporator; a bearing pump, coupled to the refrigerant circuit and to the condenser, for providing pressurized refrigerant to the refrigerant circuit; a first temperature sensor sensing a temperature Tsink of a heat exchange fluid at the condenser and providing a temperature signal representative of the temperature Tsink of the heat exchange fluid at the condenser; a second temperature sensor sensing a temperature Tsource of a heat exchange fluid at the evaporator and providing a temperature signal representative of the temperature Tsource of the heat exchange fluid at the evaporator; and a controller for controlling activation of the compressor and bearing pump as a function of the temperature signals representative of Tsink and Tsource and providing a mode of operation with only the bearing pump being activated to cause refrigerant to flow through the evaporator.

Claim 8

Dependent Claim 203 words

A refrigeration system having a compressor rotor rotatably supported by a plurality of hydrodynamic bearings lubricated by oiless pressurized liquid refrigerant and pressurizing refrigerant which flows to a condenser providing liquid refrigerant which flows to an evaporator in fluid communication with the condenser and the compressor comprising: a refrigerant circuit, coupled to the compressor, for providing pressurized liquid refrigerant to the hydrodynamic bearings from the compressor and to the evaporator; a bearing pump, coupled to the refrigerant circuit and to the condenser, for providing pressurized refrigerant to the refrigerant circuit; a first temperature sensor sensing a temperature Tsink of a heat exchange fluid at the condenser and providing a temperature signal representative of the temperature Tsink of the heat exchange fluid at the condenser; a second temperature sensor sensing a temperature Tsource of a heat exchange fluid at the evaporator and providing a temperature signal representative of the temperature Tsource of the heat exchange fluid at the evaporator; and a controller for controlling activation of the compressor and bearing pump as a function of the temperature signals representative of Tsink and Tsource and providing a mode of operation with only the bearing pump being activated to cause refrigerant to flow through the evaporator.

Claim 9

Dependent Claim 22 words

A refrigeration system in accordance with claim 6 wherein: the mode of operation occurs when (Tsource-Tsink)≧TDiFF2 with TDiFF2 by a temperature difference.

Claim 10

Independent Claim 153 words

A method of operating a refrigeration system having a compressor rotor rotatably supported by a plurality of hydrodynamic bearings lubricated by pressurized liquid refrigerant provided from at least one of a bearing pump and the compressor rotor and pressurizing refrigerant which flows to the condenser providing liquid refrigerant which flows to an evaporator in fluid communication with the condenser and the compressor comprising: sensing a first temperature Tsink of a heat exchange fluid at the condenser; sensing a second temperature Tsource of a heat exchange fluid at the evaporator; and controlling activation of the bearing pump and the compressor as a function of the temperatures Tsink and Tsource to provide three modes of operation with the first mode of operation being activation of only the compressor, the second mode of operation being activation of the bearing pump and the compressor and the third mode of operation being activation of only the bearing pump.

Claim 11

Independent Claim 153 words

A method of operating a refrigeration system having a compressor rotor rotatably supported by a plurality of hydrodynamic bearings lubricated by pressurized liquid refrigerant provided from at least one of a bearing pump and the compressor rotor and pressurizing refrigerant which flows to the condenser providing liquid refrigerant which flows to an evaporator in fluid communication with the condenser and the compressor comprising: sensing a first temperature Tsink of a heat exchange fluid at the condenser; sensing a second temperature Tsource of a heat exchange fluid at the evaporator; and controlling activation of the bearing pump and the compressor as a function of the temperatures Tsink and Tsource to provide three modes of operation with the first mode of operation being activation of only the compressor, the second mode of operation being activation of the bearing pump and the compressor and the third mode of operation being activation of only the bearing pump.

Claim 12

Dependent Claim 22 words

A method in accordance with claim 8 wherein: the first mode of operation occurs when (Tsource-Tsink)<TDiFF1 with TDiFF1 being a temperature difference.

Claim 13

Dependent Claim 30 words

A method in accordance with claim 8 wherein: the second mode of operation occurs when TDiFF1≦(Tsource-Tsink)<TDiFF2 with TDiFF1 being a first temperature difference and TDiFF2 being a second temperature difference.

Claim 14

Dependent Claim 22 words

A method in accordance with claim 8 wherein: the third mode of operation occurs when (Tsource-Tsink)≧TDiFF2 with TDiFF2 being a temperature difference.

Claim 15

Dependent Claim 47 words

A method in accordance with claim 10 wherein: the first mode of operation occurs when (Tsource-Tsink)<TDiFF1; the second mode of operation occurs when TDiFF1≦(Tsource-Tsink)<TDiFF2; and the third mode of operation occurs when (Tsource-Tsink)≧TDiFF1; and TDiFF1 is a first temperature difference and TDiFF2 is a second temperature difference.

Claim 16

Independent Claim 138 words

A method of operating a refrigeration system having a compressor rotor rotatably supported by a plurality of hydrodynamic bearings lubricated by pressurized liquid refrigerant provided from at least one of a bearing pump and the compressor rotor and pressurizing refrigerant which flows to the condenser providing liquid refrigerant which flows to an evaporator in fluid communication with the condenser and the compressor comprising: sensing a first temperature Tsink of a heat exchange fluid at the condenser; sensing a second temperature Tsource of a heat exchange fluid at the evaporator; and controlling activation of the bearing pump and the compressor as a function of the temperatures Tsink and Tsource and providing a mode of operation with only the bearing pump being actuated to cause refrigerant to flow through the evaporator to cool the heat exchange fluid at the evaporator.

Claim 17

Independent Claim 138 words

A method of operating a refrigeration system having a compressor rotor rotatably supported by a plurality of hydrodynamic bearings lubricated by pressurized liquid refrigerant provided from at least one of a bearing pump and the compressor rotor and pressurizing refrigerant which flows to the condenser providing liquid refrigerant which flows to an evaporator in fluid communication with the condenser and the compressor comprising: sensing a first temperature Tsink of a heat exchange fluid at the condenser; sensing a second temperature Tsource of a heat exchange fluid at the evaporator; and controlling activation of the bearing pump and the compressor as a function of the temperatures Tsink and Tsource and providing a mode of operation with only the bearing pump being actuated to cause refrigerant to flow through the evaporator to cool the heat exchange fluid at the evaporator.

Claim 18

Dependent Claim 21 words

A method in accordance with claim 13 wherein: the mode of operation occurs when (Tsource-Tsink)≧TDiFF2 with TDiFF2 by a temperature difference.

Claim 19

Dependent Claim 84 words

A refrigeration system in accordance with claim 1 wherein: the compressor is a multiple stage compressor; and further comprising a first subcooler and a first expansion valve contained in the refrigerant circuit, the first expansion valve expanding refrigerant flowing from the first subcooler to cool refrigerant flowing through the first subcooler and refrigerant flowing from the first subcooler after expansion by the first expansion valve flowing to an interstage point in the compressor through which compressed gas from one stage flows to another stage.

Claim 20

Dependent Claim 30 words

A refrigeration system in accordance with claim 15 wherein: the refrigerant flows through the refrigerant circuit from the first subcooler after being cooled by the subcooler to the hydrodynamic bearings.

Claim 21

Dependent Claim 99 words

A refrigeration system in accordance with claim 16 further comprising: a second subcooler and a second expansion valve contained in the refrigeration circuit which receive liquid refrigerant flowing from the first subcooler, the second expansion valve expanding refrigerant flowing from the second subcooler to cool refrigerant flowing through the second subcooler and refrigerant flowing from the second subcooler after cooling by the second subcooler flowing to the hydrodynamic bearings and then to the evaporator and the expanded refrigerant flowing from the second subcooler flowing to an inlet of the compressor; and wherein the refrigerant is a non-azeotropic binary refrigerant.

Claim 22

Dependent Claim 29 words

A refrigeration system in accordance with claim 2 wherein: only the bearing pump is activated under the control of the controller when (Tsource-Tsink)≧TDiFF2 with TDiFF2 being a temperature difference.

Claim 23

Dependent Claim 84 words

A refrigeration system in accordance with claim 18 wherein: the compressor is a multiple stage compressor; and further comprising a first subcooler and a first expansion valve contained in the refrigerant circuit, the first expansion valve expanding refrigerant flowing from the first subcooler to cool refrigerant flowing through the first subcooler and refrigerant flowing from the first subcooler after expansion by the first expansion valve flowing to an interstage point in the compressor through which compressed gas from one stage flows to another stage.

Claim 24

Dependent Claim 30 words

A refrigeration system in accordance with claim 19 wherein: the refrigerant flows through the refrigerant circuit from the first subcooler after being cooled by the subcooler to the hydrodynamic bearings.

Claim 25

Dependent Claim 29 words

A refrigeration system in accordance with claim 3 wherein: only the bearing pump is activated under the control of the controller when (Tsource-Tsink)≧TDiFF2 with TDiFF2 by a temperature difference.

Claim 26

Dependent Claim 84 words

A refrigeration system in accordance with claim 21 wherein: the compressor is a multiple stage compressor; and further comprising a first subcooler and a first expansion valve contained in the refrigerant circuit, the first expansion valve expanding refrigerant flowing from the first subcooler to cool refrigerant flowing through the first subcooler and refrigerant flowing from the first subcooler after expansion by the first expansion valve flowing to an interstage point in the compressor through which compressed gas from one stage flows to another stage.

Claim 27

Dependent Claim 30 words

A refrigeration system in accordance with claim 22 wherein: the refrigerant flows through the refrigerant circuit from the first subcooler after being cooled by the subcooler to the hydrodynamic bearings.

Claim 28

Dependent Claim 84 words

A refrigeration system in accordance with claim 6 wherein: the compressor is a multiple stage compressor; and further comprising a first subcooler and a first expansion valve contained in the refrigerant circuit, the first expansion valve expanding refrigerant flowing from the first subcooler to cool refrigerant flowing through the first subcooler and refrigerant flowing from the first subcooler after expansion by the first expansion valve flowing to an interstage point in the compressor through which compressed gas from one stage flows to another stage.

Claim 29

Dependent Claim 30 words

A refrigeration system in accordance with claim 24 wherein: the refrigerant flows through the refrigerant circuit from the first subcooler after being cooled by the subcooler to the hydrodynamic bearings.

Claim 30

Dependent Claim 84 words

A refrigeration system in accordance with claim 7 wherein: the compressor is a multiple stage compressor; and further comprising a first subcooler and a first expansion valve contained in the refrigerant circuit, the first expansion valve expanding refrigerant flowing from the first subcooler to cool refrigerant flowing through the first subcooler and refrigerant flowing from the first subcooler after expansion by the first expansion valve flowing to an interstage point in the compressor through which compressed gas from one stage flows to another stage.

Claim 31

Dependent Claim 30 words

A refrigeration system in accordance with claim 26 wherein: the refrigerant flows through the refrigerant circuit from the first subcooler after being cooled by the subcooler to the hydrodynamic bearings.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1994-09-23	1995-03-25	1995-09-24	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1998-09-23	1999-03-25	1999-09-24	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2002-09-23	2003-03-25	2003-09-24	$7700.00	Window Closed / Lapsed

Refrigeration system with oiless compressor supported by hydrodynamic bearings with multiple operation modes and method of operation

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