Methods and systems are provided for mitigating noise generated by a compressor operating at low flow rates. A swirl device with two concentric flow passages upstream of the compressor directs intake air flow to the compressor through two different flow paths, depending on air flow rates. Angled swirl vanes at an outlet of the swirl device pre-whirl the air flowing to the compressor to reduce noise generation at low air flow rates.

A turbomachinery assembly has a fluid inlet positioned to facilitate the passage of a fluid. The turbomachinery inlet may need a device which can produce inlet swirl or no swirl based on the operation conditions. In this invention, an inlet swirl device is designed to produce the inlet swirl with only one asymmetric automatic valve. No actuator is needed to control the valve. The valve opening is automatic adjusted based on the inlet flow rate. An inlet vane ring assembly is disposed adjacent the inlet and includes a plurality of vanes in the circumferential direction. The vane ring is not movable, but can produce different magnitudes of swirl.

An assembly can include a compressor housing, an adjustable wall disposed within the compressor housing that defines an air inlet to an inducer portion of a compressor wheel, and an adjustment mechanism to adjust the wall and thereby adjust at least a diameter of the air inlet. Various other examples of devices, assemblies, systems, methods, etc., are also disclosed.

A centrifugal compressor for a turbocharger includes an inlet-adjustment mechanism in an air inlet for the compressor, operable to move between an open position and a closed position in the air inlet. The inlet-adjustment mechanism includes an axially elongated ring. In the open position, the radially outer surface of the ring is spaced from a tapering inner surface of the air inlet so that air can flow in an annular passage between the tapering surface and the ring. In the closed position, the ring abuts the tapering surface to close off the annular passage, whereby the effective inlet diameter is then defined by the inner diameter of the ring at its trailing edge. Movement of the inlet-adjustment mechanism from the open position to the closed position is effective to shift the compressor's surge line to lower flow rates.

A centrifugal compressor includes: a housing including an intake flow path; a compressor impeller arranged in the intake flow path; a movable portion arranged upstream of the compressor impeller in a flow of an intake air; and a groove formed in an area other than a surface located on a downstream side in the flow of the intake air in the movable portion.

A blower for an HVAC system, the blower includes a housing with an intake and an outlet, a fan or blower wheel disposed within the housing and configured to draw air into the housing via the intake and to exhaust air from the housing through the outlet, and an adjustable cutoff plate configured to be moved between at least a first position defining a first cutoff angle and a second position defining a second cutoff angle.

A dryer assembly for a vehicle wash system for emitting high velocity air onto a vehicle exterior includes a housing having an air inlet and an outlet. The air inlet is in communication with a motor assembly having an operating and a non-operating mode. The assembly also includes a gate mechanism in communication with the air inlet. The gate mechanism includes a plurality of pedals that are each pivotable between a first position and a second position. The gate mechanism is in communication with a controller, which directs movement of the plurality of pedals from the first position where the plurality of pedals surround the inlet opening such that air can flow into the housing and the second position where each of the plurality of pedals covers a portion of the inlet opening such that in their entirety the plurality of pedals obstruct the inlet opening to prevent air for flowing into the housing.

A centrifugal refrigerant compressor system includes an impeller connected to a shaft. A diffuser is arranged on a downstream side of the impeller and is configured to regulate refrigerant flow exiting the impeller. A magnetic bearing supports the shaft. A sensing element is configured to produce an output relating to a shaft condition. A controller is configured to receive the output and determine an undesired impeller operating condition based upon the shaft condition. The controller is configured to command the diffuser to a desired state in response to the undesired impeller operating condition.

A centrifugal compressor includes a volute base block, a volute cover plate, an impeller, a diffuser-adjusting assembly, a radial constraint assembly, an axial constraint assembly and a driving assembly. A diffuser and a connected volute are formed between the cover plate and the base block. The impeller discharges gas to the centrifugal compressor through the diffuser and the volute. The diffuser adjustment assembly includes a driving ring, a driving rod, a pin and a diffuser ring. The radial constraint assembly is disposed on an inner circumference surface of the driving ring. The axial constraint assembly on an outer circumference surface of the driving ring is located between the top and bottom portions. The drive assembly is to rotate the driving ring. When the driving ring rotates, the pin slides along the pin track, and the driving rod displaces the diffuser ring to adjust a flow-path width of the diffuser.

A centrifugal fan and a dryer, where the centrifugal fan includes a shell, a driving mechanism, an impeller and a volute tongue arranged in the shell, the driving mechanism is connected with the tongue and can drive the tongue to rotate between a first limit position and a second limit position, the tongue includes a first volute tongue part and a second volute tongue part; when the tongue is located at the first limit position and the impeller rotates forwards, the first tongue part abuts against the inner wall of one side of the shell in a sealed mode, the second tongue part can cut the air blown by the impeller, and when the tongue is located at the second limit position and the impeller rotates reversely, the first tongue part can cut air blown by the impeller.