A method and system are provided for cooling a heat-exchanger in a wind turbine that has an electric generator with a cooling air flow directed therethrough. Effluent cooling air flow from the electric generator is directed into an air ejector pump and acts as motive air through the air ejector pump. Cold air is drawn into the air ejector pump by the vacuum generated by the motive air moving through the air ejector pump. The heat exchanger is disposed in-line with the cold air flow so that the cold air is drawn through the heat-exchanger, removes heat from the fluid circulated through the heat-exchanger, and becomes heated air that is combined with the motive air and discharged from the nacelle.

The present invention relates to a wind turbine cooling system configured to cool components of a wind turbine, the wind turbine having a nacelle, comprising a cooling medium configured to be circulated in a cooling circuit, the cooling circuit is fluidly connecting the components and a cooling device, the cooling device is arranged on an exterior face of the nacelle and is exposed to ambient conditions, such as wind flow and ambient air temperature outside the nacelle, the cooling medium is cooled in the cooling device by wind flow passing through the cooling device, the cooling medium is circulated from the cooling device to the components, wherein a first temperature altering section is fluidly connected with the cooling circuit upstream of the cooling device, the first temperature altering section being configured to heat the cooling medium before entering into the cooling device, and a second temperature altering section is fluidly connected with the cooling circuit downstream of the cooling device, the second temperature altering section being configured to cool the cooling medium after it has left the cooling device.

A slip ring system of an electrically excited dynamoelectric machine can be designed to be closed or open and includes a carrier segment configured to include a brush holder which includes a brush pocket for receiving a brush. The brush holder includes means for cooling the brush in the brush holder and/or for cooling the brush holder and has a surface-enlarging structure so as to enable a cooling air flow to be guided within the slip ring system and thereby cool the brush holder and/or brush pocket.

A generator, which may be used in a wind turbine, has a first stationary component carrying a first winding configuration and a second rotating component carrying a second winding configuration. The second rotating component includes a body portion and a plurality of teeth spaced around and extending radially from the body portion. The second winding configuration is arranged in slots defined between adjacent teeth. A housing is arranged around and rotates with the body portion. A heat exchange circuit is arranged on the second rotating component and includes a coolant channel defined in the teeth; a pump; and a heat exchanger arranged on the housing so as to rotate with the housing, the heat exchanger transverse to a rotational direction of the housing.

An axial flow impeller includes a hub and a blade at the hub. A blade edge of the blade includes a blade root edge, a front blade edge, a blade top edge, and a rear blade edge connected sequentially. The blade includes a divider strip arranged between the front blade edge and the rear blade edge and connecting the blade root edge and the blade top edge. At a same circumference, a ratio between a circumferential span from the divider to the front blade edge and a circumferential span from the front blade edge to the rear blade edge is equal to or greater than 0.2 and equal to or smaller than 0.4, a thickness of the divider strip is greater than thicknesses of other portions of the blade, and a thickness of the rear blade edge is smaller than a thickness of the front blade edge.

A wind turbine, including a main gear box, which is lubricated and/or cooled by oil, and a thermosiphon cooling system for cooling the oil is provided. The thermosiphon cooling system solves the main challenges facing the oil cooling systems in wind turbines. The high efficiency of the evaporation heat transfer mechanism gives the capacity to transfer the required heat load in relatively smaller size system. In this way, installation space is reduced. The thermosiphon cooling system has no service requirements over the lifetime of the wind turbine since the thermosiphon cooling system has no moving parts. Costs are saved since the simplicity of the thermosiphon cooling system adds a big value to the system business case.

The present invention discloses a novel apparatus and methods for providing a flow of cooling air to one or more turbine nozzles or turbine blade outer air seals. The flow of cooling air is provided by an external source and regulated in order to improve turbine nozzle and air seal cooling efficiency and component life.

A ceiling fan includes a fan body, a sensing unit and a control unit. The fan body includes a base seat, a plurality of fan blades mounted to the base seat, and a motor mounted to the base seat for driving rotation of the fan blades about the base seat. The sensing unit includes an outer casing, a room temperature sensor, and a body temperature sensor. The control unit is mounted to the fan body, in communication with the room temperature sensor, the body temperature sensor and the motor, and operable to adjust a rotational speed of the fan blades by controlling the motor according to a room temperature and a body temperature respectively sensed by the room temperature sensor and the body temperature sensor.

A wave power generation system includes: a hydraulic pump device configured to operate by force of a wave to discharge an operating liquid to a main passage; a hydraulic motor device configured to be rotated by the operating liquid flowing through the main passage; a power generator configured to be driven by the hydraulic motor to generate electric power; and a heat exchanger device configured to perform heat exchange of the operating liquid. The heat exchanger device includes a heat exchange motor device connected to the main passage through a sub passage and configured to be operated by the operating liquid introduced through the sub passage, a refrigerant pump device driven by the heat exchange motor device and configured to suck and discharge a refrigerant liquid, and a heat exchanger to which the refrigerant liquid discharged from the heat exchange pump device and the operating liquid are introduced.

A linear compressor includes a cylinder, a frame, and a discharge unit. The frame includes a discharge frame surface coupled to the discharge unit and a gas hole recessed from the discharge frame surface. The discharge unit includes a bearing refrigerant passage extending toward the gas hole so that a portion of the refrigerant flowing into the discharge space flows into the gas hole.