Refrigeration system with brushless dc motor compressor drive

Patent metadata

Field	Value
Publication number	US-2016209097-A1
Application number	US-201614996062-A
Country	US
Kind code	A1
Filing date	Jan 14, 2016
Priority date	Jan 16, 2015
Publication date	Jul 21, 2016
Grant date	—

Abstract

A refrigeration system for a temperature-controlled storage device includes a refrigeration circuit, a cooling circuit, and a controller. The refrigeration circuit includes a compressor driven by a brushless DC motor operable at multiple different speeds, a first heat exchanger, an expansion device, and a cooling unit in fluid communication via a first working fluid. The cooling circuit includes a pump and a second heat exchanger in fluid communication with the first heat exchanger via a second working fluid such that the first heat exchanger is liquid-cooled by the second working fluid. The controller operates the brushless DC motor at multiple different speeds to accommodate multiple different thermal loads experienced by the refrigeration system. Each of the speeds corresponds to a different thermal load. The controller modulates the speed of the brushless DC motor to maintain a desired temperature of a temperature-controlled space within the temperature-controlled device.

First claim

What is claimed is:

1 . A refrigeration system for a temperature-controlled storage device, comprising:
a refrigeration circuit including a compressor driven by a brushless DC motor operable at multiple different speeds, a first heat exchanger, an expansion device, and a cooling unit in fluid communication via a first working fluid; a cooling circuit including a pump and a second heat exchanger in fluid communication with the first heat exchanger via a second working fluid such that the first heat exchanger is liquid-cooled by the second working fluid; and a controller that operates the brushless DC motor at multiple different speeds to accommodate multiple different thermal loads experienced by the refrigeration system, each of the speeds corresponding to a different thermal load, wherein the controller modulates a speed of the brushless DC motor to maintain a desired temperature of a temperature-controlled space within the temperature-controlled storage device.

2 . The refrigeration system of claim 1 , wherein the refrigeration circuit further includes a first fan that provides an airflow across the cooling unit to cool the airflow;
wherein the cooled airflow is provided to the temperature-controlled space within the temperature-controlled device.

3 . The refrigeration system of claim 2 , wherein the controller modulates a speed of the first fan to modulate a rate of heat transfer experienced by the temperature-controlled space to maintain the desired temperature of the temperature-controlled space.

4 . The refrigeration system of claim 2 , wherein the controller operates the expansion device to control a flow rate of the first working fluid passing therethrough and entering the cooling unit to modulate a rate of heat transfer experienced by the airflow flowing across the cooling unit to maintain the desired temperature of the temperature-controlled space.

5 . The refrigeration system of claim 2 , wherein the controller modulates the speed of the brushless DC motor to control a flow rate of the first working circulating through the refrigeration circuit to modulate a rate of heat transfer experienced by the airflow flowing across the cooling unit to maintain the desired temperature of the temperature-controlled space.

6 . A refrigeration circuit for a temperature-controlled storage device, comprising:
a compressor that circulates a working fluid through the refrigeration circuit; a variable-speed brushless DC motor that operates to drive the compressor; a heat exchanger that receives the working fluid from the compressor and provides cooling for the working fluid; an expansion device that receives the cooled working fluid from the heat exchanger and expands the working fluid to a lower-temperature state; a cooling element that receives the expanded working fluid from the expansion device and provides the working fluid to the compressor; and a controller that operates the variable-speed brushless DC motor at multiple different speeds to accommodate multiple different thermal loads, each of the speeds corresponding to a different thermal load, wherein the controller modulates a speed of the brushless DC motor to maintain a desired temperature of a temperature-controlled space within the temperature-controlled storage device; wherein the compressor, the heat exchanger, the expansion device, and the cooling element are in fluid communication via the working fluid.

7 . The refrigeration circuit of claim 6 , further comprising a fan that provides an airflow across the cooling element to cool the airflow;
wherein the cooled airflow is provided to the temperature-controlled space within the temperature-controlled device.

8 . The refrigeration circuit of claim 7 , wherein the controller modulates a speed of the fan to modulate a rate of heat transfer experienced by the temperature-controlled space to maintain the desired temperature of the temperature-controlled space.

9 . The refrigeration circuit of claim 6 , wherein the controller operates the expansion device to control a flow rate of the working fluid passing therethrough and entering the cooling element to modulate a rate of heat transfer experienced by an airflow flowing across the cooling element to maintain the desired temperature of the temperature-controlled space.

10 . The refrigeration circuit of claim 6 , wherein the controller modulates the speed of the variable speed brushless DC motor to control a flow rate of the working fluid circulating through the refrigeration circuit to modulate a rate of heat transfer experienced by an airflow flowing across the cooling element to maintain the desired temperature of the temperature-controlled space.

11 . The refrigeration circuit of claim 6 , further comprising a fan that provides an airflow across the heat exchanger to cool the working fluid flowing therethrough such that the heat exchanger is air-cooled.

12 . The refrigeration circuit of claim 11 , further comprising a pressure sensor configured to measure a pressure of the working fluid at an inlet of the heat exchanger;
wherein the controller modulates a speed of the fan to control the pressure of the working fluid at the inlet of the heat exchanger.

13 . The refrigeration circuit of claim 6 , wherein the heat exchanger is liquid-cooled with a second working fluid.

14 . The refrigeration circuit of claim 13 , wherein the controller modulates a flow rate of the second working fluid with a valve to modulate a rate of heat transfer between the working fluid and the second working fluid flowing through the heat exchanger to maintain a desired pressure of the working fluid at an inlet of the heat exchanger.

15 . A refrigeration circuit for a temperature-controlled storage device, comprising:
a brushless DC motor operable at multiple different speeds, the brushless DC motor driving a compressor that circulates a working fluid through the refrigeration circuit; and a controller that operates the brushless DC motor at multiple different speeds to accommodate multiple different thermal loads, each of the speeds corresponding to a different thermal load, wherein the controller modulates a speed of the brushless DC motor to maintain a desired temperature of a temperature-controlled space within the temperature-controlled storage device.

16 . The refrigeration circuit of claim 15 , further comprising:
a cooling unit configured to provide cooling for the temperature-controlled space by transferring heat from the temperature-controlled space to the working fluid; and a fan that provides an airflow across the cooling unit to cool the airflow; wherein the cooled airflow is provided to the temperature-controlled space within the temperature-controlled storage device.

17 . The refrigeration circuit of claim 16 , wherein the controller modulates a speed of the fan to modulate a rate of heat transfer experienced by the temperature-controlled space to maintain the desired temperature of the temperature-controlled space.

18 . The refrigeration circuit of claim 15 , wherein the controller modulates the speed of the brushless DC motor to control a flow rate of the working fluid circulating through the refrigeration circuit.

19 . The refrigeration circuit of claim 15 , further comprising:
a heat exchanger configured to provide cooling for the working fluid; and a pressure sensor configured to measure a pressure of the working fluid at an inlet of the heat exchanger; wherein the controller modulates a speed of the fan to control the pressure of the work

Assignees

• Hill Phoenix Inc

Inventors

• Choueifati Jules G
• Swofford Timothy D
• Rathje Neil J

Classifications

• F25B2600/2513

  Expansion valves · CPC title

• F25B2600/0253

  with variable speed · CPC title

• F25B2600/13

  Pump speed control · CPC title

• F25B2700/195

  of the condenser · CPC title

• F25B2600/112

  of evaporator fans · CPC title