Capacity modulation compressor and air conditioning system having the same

• US 20100017037A1
• Filed: 01/15/2009
• Published: 01/21/2010
• Est. Priority Date: 07/16/2008
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Kang-Wook, Lee, Geun-Hyoung, Nam, Hyuk, Ha, Seung-Hyoung
• Granted Patent: US 8,069,685 B2
• Time in Patent Office: Days
• US Class Current: 700/275
• CPC Class Codes: F25B 2400/0751 the compressors having different capacities
• CPC Class Codes: F25B 2500/26 characterised by the startup of the refrigeration cycle
• CPC Class Codes: F25B 2600/021 Inverters therefor
• CPC Class Codes: F25B 2600/0251 with on-off operation
• CPC Class Codes: F25B 49/025 Motor control arrangements
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

Provided is an air conditioning system comprised of a plurality of indoor units connected to each other in parallel, each having an expansion valve, and an outdoor unit including a plurality of compressors, in which at least one of the compressors provided to the outdoor unit is a capacity modulation compressor including an electromotive driving unit for driving a plurality of compression units capable of selectively compressing a working fluid, and the electromotive driving unit for the capacity modulation compressor has a stator with a coil wound around thereon and a rotor rotating inside the stator, the rotor being an LSPRM including a rotor core, flux barriers, permanent magnets and conductive bars.

Claims

1. An air conditioning system comprising a plurality of indoor units connected to each other in parallel, each having an expansion valve, and an outdoor unit including a plurality of compressors,

wherein at least one of the compressors provided to the outdoor unit is a capacity modulation compressor including an electromotive driving unit for driving a plurality of compression units capable of selectively compressing a working fluid;

and

wherein the electromotive driving unit for the capacity modulation compressor has a stator with a coil wound around thereon and a rotor rotating inside the stator, the rotor being an LSPRM including a rotor core, flux barriers, permanent magnets and conductive bars.

2. The system of claim 1, wherein the plurality of compressors include one capacity modulation compressor and one fixed capacity compressor.

3. The system of claim 2, further comprising:

a controller for controlling a compressing capacity of the capacity modulation compressor and for selectively operating the capacity modulation compressor and the fixed capacity compressor, so as to modulate the whole compressing capacity of the modulation compressor and fixed-capacity compressor as various steps.

4. The system of claim 2, wherein the fixed-capacity compressor includes an inductor motor or an LSPRM, as an electromotive driving unit.

5. The system of claim 1, wherein the outdoor unit is provided with two capacity modulation compressor s, each being driven by an LSPRM.

6. The system of claim 5, wherein the two capacity modulation compressors have different capacity values from each other.

7. The system of claim 5, further comprising:

a controller for controlling the operation mode and compressing capacity of each of the capacity modulation compressor s, so as to modulate a total compressing capacity of the capacity modulation compressor s in multiple steps.

8. The system of claim 1, wherein the electromotive driving unit for the capacity modulation compressor includes a capacitor which has an optimized compressing capacity as the rotor produces a torque for a compression unit to be able to compress a working fluid at a maximum compressing capacity, and which is connected to the stator coil.

9. The system of claim 8, wherein a compression capacity of the compression unit is modulated to make a load torque less than a starting torque of the rotor during a startup applied to the compression unit.

10. The system of claim 1, wherein the electromotive driving unit for the capacity modulation compressor includes two or more capacitors connected to each other in parallel, and a switch for controlling a short state of the capacitor.

11. The system of claim 10, wherein, during a startup, a compressing capacity of the compression unit of the capacity modulation compressor is modulated to generate a load torque lower than a starting torque generated in summation of capacities of capacitors after the switch is turned on.

12. The system of claim 10, further comprising:

a controller for controlling a compression unit, so that during a startup a compressing capacity of the capacity modulation compressor generates a load torque lower than a starting torque generated in summation of capacities of capacitors after the switch is turned on.

13. The system of claim 1, further comprising:

a controller for controlling a compressing capacity of the compressor depending on the operation mode of each of the plurality of indoor units.

18. The system of claim 1, wherein the capacity modulation compressor comprises a plurality of rotary compression units, and at least one of the rotary compression units includes a vane slit in which a vane is inserted, a back pressure space communicating with the vane slit from an external diameter side of the vane slit, and a vane control unit for supplying a suction pressure or a discharge pressure to a rear face of the vane to support the vane and for supplying a discharge pressure to a lateral face of the vane at the same time, such that a difference between the pressure applied to the rear face of the vane and the pressure applied to the lateral face of the vane makes the vane bound or released, thereby making the vane press-welded to or separated from a rolling piston, and

wherein a total compressing capacity of the compression units is modulated by controlling the operation mode of at least one of the rotary compression units.

19. The system of claim 18, wherein the vane control unit includes a back pressure connection pipe via which a working fluid is introduced into the back pressure space;

a low-pressure connection pipe connected to the back pressure connection pipe, via which a low-pressure non-compressed working fluid flows;

a high-pressure connection pipe connected to the back pressure connection pipe, via which a high-pressure compressed working fluid flows;

a valve for opening/closing the low-pressure connection pipe; and

a valve for opening/closing the high-pressure connection pipe.

20. The system of claim 18, wherein the vane control unit includes a back pressure connection pipe via which a working fluid is introduced into the back pressure space;

a low-pressure connection pipe connected to the back pressure connection pipe, via which a low-pressure non-compressed working fluid flows;

a high-pressure connection pipe connected to the back pressure connection pipe, via which a high-pressure compressed working fluid flows;

a switch valve for regulating the flow of a working fluid being introduced into the back pressure space through the back pressure connection pipe.

21. The system of claim 1, wherein the capacity modulation compressor includes a plurality of rotary compression units, a suction pipe passing through a casing to let a working fluid intaken by a cylinder, and a suction valve installed on the suction pipe to open or close the suction pipe, such that a total compressing capacity of the compression units varies depending on whether the suction valve is open or closed.

22. The system of claim 1, wherein, during a startup of the capacity modulation compressor, a compressing capacity of the compression unit is lowered and a smaller load is applied to the electromotive driving unit.

14. An air conditioning system provided with a plurality of compressors, a condenser, a four-way valve, and a plurality of heat exchangers,

wherein at least one of the plurality of compressors is a capacity modulation compressor comprising:

an electromotive driving unit including a stator having a coil winding portion to which power is supplied, and rotor which has conductive bars, flux barriers, permanent magnets inserted in the flux barriers, rotates due to interactive electromagnetic forces, an induction torque generated between the conductive bars and the coil winding portion of the stator, an reluctance torque generated between flux barriers and the coil winding portion of the stator and a magnetic torque generated between the permanent magnetic and the coil winding portion of the stator, and has different load torques assigned in a startup operation and in a normal operation, and a capacitor electrically connected to the coil winding portion;

a compression unit with a variable compressing capacity in compression of a working fluid; and

a controller for controlling operation of a plurality of heat exchangers, and for controlling operation of a plurality of compressors and a compressing capacity of a capacity modulation compressor according to a change in a required cooling capacity for the plurality of heat exchangers, so as to modulate a total capacity of the plurality of compressors in multiple steps.

15. The system of claim 14, wherein the plurality of compressors includes one fixed capacity/fixed speed compressor and one capacity modulation compressor, and a combination of compressing capacities of the plurality of compressors is modulated linearly.

16. The system of claim 14, wherein the plurality of compressors includes two or more capacity modulation compressor s and a combination of compressing capacities of the plurality of compressors is modulated linearly.

17. The system of claim 14, wherein the plurality of compressors includes one inverter compressor and one capacity modulation compressor, and a combination of compressing capacities of the plurality of compressors is modulated linearly.

23. A method of controlling a capacity modulation compressor, comprising the steps of:

receiving an input data on a required cooling capacity for an indoor unit;

starting an electromotive driving unit of the capacity modulation compressor at a lower load regardless of the required cooling capacity for the indoor unit; and

operating the electromotive driving unit of the capacity modulation compressor at a synchronous speed, under a load corresponding to the required cooling capacity for the outdoor unit.

24. A method of controlling an air conditioning system, comprising the steps of:

receiving an on/off signal from each of a plurality of indoor units and receiving an input data on a required cooling capacity for each;

determining the operation mode and compressing capacity for each of the plurality of compressors including at least one capacity modulation compressor, in accordance with the input data on required cooling capacities for the plurality of indoor units,

starting an electromotive driving unit of the capacity modulation compressor at a lower load, regardless of the compressing capacity of the capacity modulation compressor having been determined on the basis of the input data on required cooling capacities for the plurality of indoor units; and

operating the electromotive driving unit of the capacity modulation compressor at a synchronous speed, under the compressing capacity having been determined on the basis of the required cooling capacity for the indoor unit.