A method of operating a heat exchanger system in which a compressor, which is drivable by a motor, is fluidly interposed between an evaporator and a condenser following receipt of a shutdown command is provided. The method includes positioning inlet guide vanes (IGVs) of the compressor in a first position in the event of at least one of a first precondition being in effect and the first and a second precondition both not being in effect. The method further includes positioning the IGVs in a second position in an event the first precondition is not in effect but the second precondition is in effect, ramping a speed of the compressor down until a third precondition takes effect, removing power from the motor and positioning the IGVs in the first position once power is removed from the motor.

The present embodiments disclose a mechanical shaft lock for use in electric submersible pumps. The mechanical shaft lock can include one or more shear pins. When an end of the shear pin, e.g., shear pin head, lines up with one or more shearing slots on the MSL or pump shaft, the shear pin engages and stops the rotation of the pump shaft and motor attached to the pump. The shaft lock can be engaged for installing an ESP, disengaged for production after installing by breaking the shear pin upon start-up, and re-engaged for removing the ESP from the wellbore. In some embodiments, the MSL may be configured to be disengaged and re-engaged to deal with well kicks.

A gas turbine engine includes a fan and a first drive shaft connected to the fan. A fan drive gear box connects the first drive shaft to a second drive shaft and is configured to allow the first drive shaft to rotate at a different speed than the second drive shaft. The gas turbine engine also includes a sprag clutch disposed circumferentially around the first shaft and connected to the first drive shaft. The sprag clutch is configured to allow rotation of the first drive shaft and the fan in a first direction while prohibiting rotation of the fan and the first drive shaft in a second direction.

A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a fan and a braking system. The braking system is configured to selectively engage the fan during ground windmilling to apply a first level of braking to slow rotation of the fan. Further, when the rotation of the fan sufficiently slows, the braking system is further configured to apply a second level of braking more restrictive than the first level of braking.

In one aspect, a fan array fault response control system is provided for a cooling tower. The fan array fault response control system includes a fan interface configured to be in communication with a plurality of fans of the cooling tower and a processor operably coupled to the fan interface. The processor is configured to detect at least one non-operational fan of the plurality of fans. The processor configured to effect, in response to detecting the at least one non-operational fan, a reduced fan speed of at least one operational fan of the plurality of fans.

A method of operating a heat exchanger system in which a compressor, which is drivable by a motor, is fluidly interposed between an evaporator and a condenser following receipt of a shutdown command is provided. The method includes positioning inlet guide vanes (IGVs) of the compressor in a first position in the event of at least one of a first precondition being in effect and the first and a second precondition both not being in effect. The method further includes positioning the IGVs in a second position in an event the first precondition is not in effect but the second precondition is in effect, ramping a speed of the compressor down until a third precondition takes effect, removing power from the motor and positioning the IGVs in the first position once power is removed from the motor.

A shaft in an electrical submersible pumping system is prevented from rotation in a backspin direction, which is in a direction opposite from its typical forward rotation during normal operation. Backspin rotation is prevented with a device that includes teeth coupled to the shaft and a stationary pawl disposed in a rotational path of the teeth. Each tooth has a forward surface that contacts the pawl during forward rotation of the shaft, the forward surfaces are each configured with a profile to slide along and past the pawl without impeding shaft rotation. Rotation in the backspin direction engages the pawl with rearward surfaces of the teeth, which are configured to impede shaft rotation when engaged. Fluid being handled by the pumping system flows through a passage in the device and absorbs friction generated thermal energy from the device.

A shaft in an electrical submersible pumping system is prevented from rotation in a backspin direction, which is in a direction opposite from its typical forward rotation during normal operation. Backspin rotation is prevented with a device that includes teeth coupled to the shaft and a stationary pawl disposed in a rotational path of the teeth. Each tooth has a forward surface that contacts the pawl during forward rotation of the shaft, the forward surfaces are each configured with a profile to slide along and past the pawl without impeding shaft rotation. Rotation in the backspin direction engages the pawl with rearward surfaces of the teeth, which are configured to impede shaft rotation when engaged. Fluid being handled by the pumping system flows through a passage in the device and absorbs friction generated thermal energy from the device.

An electrical submersible well pump assembly (ESP) has a spring brake having helical turns mounted between the shaft and one of the housings. The spring brake allows free rotation of the shaft in a driving direction and stops the shaft from rotating in a reverse direction. The spring brake may have one end be affixed to the housing to rotate in unison in both directions. Alternately, the spring brake may have one end affixed to the shaft for rotation with the shaft. Further, the spring brake could be free of being connected to either the shaft or the housing. A shear member may be mounted between the shaft and the housing to prevent any rotation of the shaft during run-in.

A gas turbine engine with a geared turbofan arrangement with a gearbox in a drive train driven by a turbine, a driving side of the gearbox being driveably connected with a propulsive fan, with at least one torque transmission device positioned in the drive train, the torque transmission device having an asymmetric torque transmission characteristic, so that torque is transmittable by the torque transmission device under a nominal rotational direction and no torque is transmittable by the torque transmission device in a non-nominal rotational direction.