# US 2013/0156544 A1 · Compressor Surge Detection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0156544 A1 - Document ID: US20130156544A1 - Status: Published application - Kind: A1 - Application number: 13/819,505 - Filed: 2012-06-06 - Published: 2013-06-20 - Earliest claimed: 2011-06-30 - Assignees: Carrier Corporation - Inventors: Vishnu M. Sishtla - Web page: https://patentgrep.com/patent/US20130156544A1 ## CPC - F04D 29/00: Details, component parts, or accessories (machine elements in general F16) - F04D 29/052: Axially shiftable rotors (F04D29/051 takes precedence {; control by creating a by-pass F04D27/0246}) - F04D 27/001: {Testing thereof; Determination or simulation of flow characteristics; Stall or surge detection, e.g. condition monitoring} - F04D 27/0261: {by varying driving speed} - F04D 29/058: magnetic; electromagnetic - Y02B 30/70: Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A compressor (22) has a housing assembly (50) with a suction port (24) and a discharge port (26). A shaft (70) is mounted for rotation about an axis (500) and an impeller (44) is mounted to the shaft to be driven in at least a first condition so as to draw fluid in through the suction port and discharge the fluid from the discharge port. A magnetic bearing system (66, 67, 68) supports the shaft. A controller (84) is coupled to a sensor (80, 82) and configured to detect at least one of surge and pre-surge rotating stall and, responsive to said detection, take action to prevent or counter surge. ## Claims ### Claim 1 A compressor (22) comprising: a housing assembly (50) having a suction port (24) and a discharge port (26); a shaft (70) mounted for rotation about an axis (500); an impeller (44) mounted to the shaft to be driven in at least a first condition so as to draw fluid in through the suction port and discharge said fluid out from the discharge port; a magnetic bearing system (66, 67, 68) supporting the shaft; a sensor (80, 82); and a controller (84) coupled to the sensor and configured to detect at least one of surge and pre-surge rotating stall and, responsive to said detection, take action to prevent or counter surge, wherein: the action comprises adjusting the clearance between the impeller and a shroud. ### Claim 2 (depends on 1) The compressor of claim 1 wherein: the housing comprises a motor compartment (60); an electric motor (42) has a stator (62) within the motor compartment and a rotor (64) within the stator. ### Claim 3 (depends on 1) The compressor of claim 1 wherein the magnetic bearing system comprises: a first radial bearing (66); a second radial bearing (67); and a thrust bearing (68). ### Claim 4 (depends on 3) The compressor of claim 3 wherein: the thrust bearing is a thrust/counterthrust bearing. ### Claim 5 (depends on 3) The compressor of claim 3 further comprising: a counterthrust bearing axially spaced apart from the thrust bearing. ### Claim 6 (depends on 1) The compressor of claim 1 wherein: the sensor comprises: a radial position sensor (82); and an axial position sensor (80); and the controller is programmed to: detect and limit synchronous vibration. ### Claim 7 (depends on 6) The compressor of claim 6 wherein: the controller is programmed to detect said rotating stall via detecting vibration and, responsive to the detected rotating stall take action distinct from the control of synchronous vibration. ### Claim 8 (depends on 1) The compressor of claim 1 wherein: the controller is programmed to detect said rotating stall by a detecting vibration. ### Claim 9 (depends on 8) The compressor of claim 8 wherein: the controller is programmed to detect said vibration from one or more bearing position sensors. ### Claim 10 (depends on 8) The compressor of claim 8 wherein: the controller is programmed to detect said vibration in a frequency range of 3-10 Hz. ### Claim 11 (depends on 1) The compressor of claim 1 wherein the controller is programmed to detect said rotating stall by: determining the presence of a vibration exceeding a threshold magnitude within a frequency range. ### Claim 12 (depends on 1) The compressor of claim 1 wherein the controller is programmed to take said action to prevent onset of surge by at least one of: increasing the compressor speed; and opening a hot gas bypass valve (42). ### Claim 13 (depends on 1) The compressor of claim 1 wherein: the impeller is a single impeller mounted to the rotor by the shaft for direct coaxial rotation with the rotor. ### Claim 14 (depends on 1) A vapor compression system comprising: the compressor of claim 1; a first heat exchanger (28) coupled to the discharge port to receive refrigerant driven in a downstream direction in the first operational condition of the compressor; an expansion device (32) downstream of the first heat exchanger; and a second heat exchanger (30) downstream of the expansion device and coupled to the suction port to return refrigerant in the first operating condition. ### Claim 15 (depends on 14) The system of claim 14 wherein: a hot gas bypass valve is positioned to bypass the first heat exchanger and convey refrigerant from the compressor to the second heat exchanger. ### Claim 16 (depends on 1) A method for operating the compressor of claim 1 comprising: driving the motor to draw the fluid in through the suction port and discharge the fluid from the discharge port; detecting the rotating stall; and responsive to the detected rotating stall, taking said action to prevent onset of surge. ### Claim 17 (canceled) ### Claim 18 (depends on 16) The method of claim 16 wherein: the clearance is adjusted while it exceeds a minimum value; and when the clearance does not exceed the minimum value, the action comprises opening a hot gas bypass valve. ### Claim 19 (depends on 18) The method of claim 18 wherein: the sensor comprises: a radial position sensor (82); and an axial position sensor (80); and the controller is programmed to: detect and limit synchronous vibration responsive to sensed output of the radial position sensor. ### Claim 20 (depends on 1) The compressor of claim 1 wherein: the controller is programmed to detect and limit said synchronous vibration responsive to input from said radial position sensor. ### Claim 21 (depends on 1) The compressor of claim 1 wherein: the sensor is a radial position sensor and the controller is configured to detect said at least one of surge and pre-surge rotating stall responsive to input from the radial position sensor.