Claims
- 1. An air-conditioning system with a refrigerant medium circulating in a refrigerant loop, said system comprising:
a variable-stroke compressor comprising a high-pressure outlet chamber, a drive chamber and an intake suction chamber; a first valve regulating a first flow of refrigerant medium from the high-pressure outlet chamber to the drive chamber; a second valve regulating a second flow of refrigerant medium from the drive chamber to the intake suction chamber; and a control unit; wherein the variable stroke of the compressor is controlled by at least one of said first flow and said second flow, and wherein said first and second valves are operable independently of each other under the control of the control unit.
- 2. The air-conditioning system of claim 1, wherein the control device is operable to set a constant pressure at a location in the refrigerant loop by means of said first and second valves, said location being one of the high-pressure outlet chamber and the intake suction chamber.
- 3. The air-conditioning system of claim 1, wherein said first valve is opened at regular intervals to ensure a sufficient supply of lubricant in said compressor, said lubricant being contained in the refrigerant medium.
- 4. The air-conditioning system of claim 1, wherein pressure levels are stabilized and regulation properties are improved by opening said first valve and said second valve simultaneously.
- 5. The air-conditioning system of claim 1, wherein an increase in performance of the air-conditioning system is achievable by keeping one of said first and second valves closed and keeping the other of said first and second valves open.
- 6. The air-conditioning system of claim 1, further comprising an evaporator connected to said compressor in said refrigerant loop, wherein said circulation of refrigerant medium through said refrigerant loop can be minimized by simultaneously opening said first and second valves, whereby said evaporator is prevented from freezing over when no cooling power is drawn from the air-conditioning system.
- 7. The air-conditioning system of claim 1, wherein the variable-stroke compressor comprises a wobble-plate with a variable tilt angle, and wherein an effective high-pressure limitation is achieved in the outlet pressure chamber through improvements in pressure regulation and in a dynamic response of said tilt angle, so that as a result the air-conditioning system can be operated at pressure levels near a permissible high-pressure limit.
- 8. The air-conditioning system of claim 1, wherein the system is selectively operable in a heat-pump mode and a refrigeration mode and wherein the outlet chamber pressure or the intake suction pressure is used as control variable depending on whether the system is used as a heat pump or as a refrigeration system.
- 9. The air-conditioning system of claim 1, wherein a target value for a pressure to be set and maintained by the control unit through said first and second valves can be adjusted within a wide range, so that appropriate pressure levels can be set for operating the system in a refrigeration mode as well as a heat pump mode.
- 10. The air-conditioning system of claim 1, wherein a cycle time of said first and second valves can be increased when the air-conditioning system is in a stationary operating mode in order to increase the useful operating life of said first and second valves.
- 11. The air-conditioning system of claim 1, wherein a cyclic actuation of the valves can be suspended when the compressor is turned off.
Priority Claims (1)
Number |
Date |
Country |
Kind |
100 58 002.5 |
Nov 2000 |
DE |
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of International Patent Application Serial No. PCT/DE01/03778, filed Sep. 26, 2001, which is hereby incorporated by reference in its entirety.
Continuations (1)
|
Number |
Date |
Country |
Parent |
PCT/DE02/03778 |
Sep 2001 |
US |
Child |
10446639 |
May 2003 |
US |