Hydraulic system and wind turbine generator provided therewith

• US 20100104439A1
• Filed: 10/28/2009
• Published: 04/29/2010
• Est. Priority Date: 10/29/2008
• Status: Active Grant

• Current Assignee: Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: Yuge, Atsushi, Hayashi, Toshikazu, Nomaguchi, Hiroyuki
• Granted Patent: US 9,169,829 B2
• Time in Patent Office: Days
• US Class Current: 416/147
• CPC Class Codes: F03D 7/02 the wind motors having rotation axis substantially parallel to the air flow entering the rotor
• CPC Class Codes: F03D 9/00 Adaptations of wind motors for special use; Combinations of wind motors with apparatus driven thereby; Wind motors specially adapted for installation in particular locations hybrid wind-photovoltaic energy systems for the generation of electric power H02S10/12
• CPC Class Codes: F03D 9/10 Combinations of wind motors with apparatus storing energy
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier

Abstract

There is provided a hydraulic pump startup control device in a hydraulic system, which avoids an overloaded state at startup to enable low-temperature, fast startup and maintaining of the temperature with low-cost means in order to improve low-temperature startability. A bypass path 19 is placed in parallel with a hydraulic main line from a hydraulic tank, and the downstream of the bypass path is made merged with the hydraulic main line. A bypass valve 3 that opens or closes the bypass path is provided in the bypass path, and a pressure sensor is provided in the inlet of a hydraulic unit in the hydraulic main line. Further, a control device 10 to which a pressure detection value in the hydraulic main line is input from the pressure sensor to open the bypass valve based on the pressure detection value upon startup of the hydraulic unit. The control device repeats on-off control to circulate oil in the bypass path while keeping the pump discharge pressure and the flow rate to open the bypass path at startup so that the actuation power of the hydraulic unit will become the maximum in order to rise the hydraulic temperature of the hydraulic main line.

Claims

1. A hydraulic system adapted to feed oil from a hydraulic tank into a hydraulic unit through a hydraulic main line by means of a hydraulic pump placed in the hydraulic main line in order to actuate the hydraulic unit with the oil, the hydraulic system comprising:

a bypass path branching off from a discharge side of the hydraulic pump in the hydraulic main line to the hydraulic tank and flow rate control means provided in the bypass path to control the flow rate of the bypass path;

a pressure sensor provided in an inlet of the hydraulic unit in the hydraulic main line; and

a control device to which a pressure detection value is input from the pressure sensor to control the flow rate control means based on the pressure detection value, wherein oil is circulated in the bypass path while keeping pump discharge pressure and the flow rate equal to or smaller than given specified values.

2. The hydraulic system according to claim 1, wherein the flow rate control means is a bypass valve that opens or closes the bypass path.

3. The hydraulic system according to claim 1, wherein the flow rate control means is a variable flow valve that controls the oil flow rate of the bypass path.

4. The hydraulic system according to claim 1, further comprising

a temperature sensor for detecting a temperature of the oil and inputting a temperature detection value to the control device, wherein

when the temperature detection value is lower than a predetermined temperature, the control device circulates the oil in the bypass path while controlling the flow rate control means, and

when the temperature detection value reaches the predetermined temperature, the control device performs control to stop oil circulation in the bypass path.

5. A wind turbine generator provided with the hydraulic system according to claim 1.