JPS5812597A - Control of rotating speed of generator with drive force from water wheel - Google Patents

Abstract

PURPOSE:To enable to constantly control the rotating speed of a generator with a simple structure by driving a hydraulic pump by a water wheel and controlling exhaust oil from the pump to supply it to a hydraulic motor for driving the generator. CONSTITUTION:A water wheel 2 is driven by the water stream of a conduit 1, and a volume type hydraulic pump 6 is driven by the wheel 2 so that the exhaust amount increases or decreases proportionally to the rotating speed. On the other hand, a pressure compensating flow rate control valve 9 supplies substantially constant flow rate oil irrespective of the pressure at the valve to a volume type hydraulic motor 7. Since the motor 7 rotates at the speed proportional to the flow rate of the supplied oil, the rotating speed of the generator 11 does not vary even if the load of the generator 11 is varied.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for controlling the rotational speed of a small generator powered by a water turbine without a rotational speed IllIII@ to a constant value.

For example, in a water supply system that has a type of water supply system that circulates and stores water on the roof of a building, etc., when there is excess water used, a water wheel is installed in the return system to recover potential energy and generate hydroelectric power. In some cases, electric equipment such as advertising towers in buildings is electrically driven.

In such a case, if pressurized water is supplied from the discharge port of a known centrifugal pump using potential energy, the impeller will be rotated by the pressurized water and torque will be generated on the shaft. If this torque drives a generator, the centrifugal pump can be used as a water wheel to generate electricity.

However, the return system described above does not always have a constant flow rate or pressure, and there is no mechanism in the centrifugal pump to control the rotation speed to a constant level in response to fluctuations in pressure or generator shaft torque. Therefore, the rotational speed of the centrifugal pump's impeller changes due to changes in the pressure of the drainage system or the shaft torque of the generator, so the rotational speed of the generator driven by the water turbine also changes. Become.

Such variations in the rotational speed of the generator are a problem, and it is essential to set the rotational speed within a certain range and keep it more or less constant. Generally, when the generator load fluctuates, the rotation speed of the generator II changes, but conventionally, the rotation speed of the generator was detected and the amount of water supplied to the centrifugal pump was adjusted so that the rotation speed remained at a constant value. Methods have been proposed to automatically control the flow rate using a flow rate control device, but the control mechanism is complex and the equipment costs are high. Considering that it is used in an energy recovery system for so-called energy saving, it is inappropriate to use such expensive equipment.

It is an object of the present invention to provide a method and device that can control the rotational speed of a power generator to a constant value.

The present invention will be described in detail below with reference to the drawings.

In FIG. 1, a pipe line 1 is connected in parallel with a control valve V provided in a main return pipe M, and a water turbine 2 (
This water turbine uses a centrifugal pump, and high-pressure water is supplied from the discharge port of the centrifugal pump, and the impeller is rotated by the water pressure to operate as a water turbine). A wheel 4 is connected to the flywheel 4, to which a positive displacement hydraulic pump 6 is connected via a coupling 5. This positive displacement hydraulic pump 6 is therefore drivingly connected to the water wheel 2 .

Therefore, a mold device may be provided in the middle as appropriate.

This positive displacement hydraulic pump 6 sucks oil from the tank T to drive a positive displacement hydraulic motor 7, and returns oil to a cooler 8.
It constitutes a hydraulic circuit that flows through the tank T. A pressure-compensated flow control valve 9 is provided between the positive-displacement hydraulic pump 6 and the positive-displacement hydraulic motor 7, and a pipe line between the pressure-compensated flow control valve 9 and the positive-displacement hydraulic pump 6 is Bypass line B is branched, and bypass line B is connected to cooler 8 with a safety valve 10 interposed therebetween. Further, a power generator 1111 is connected to the positive displacement hydraulic motor 7,
The generator 11 is operated by driving the contribution type hydraulic motor 7. This generator supplies power to, for example, lighting equipment (not shown), and in the above embodiment, the water flow in the conduit 1 drives the water turbine 2.
The positive displacement hydraulic pump 6 is driven by this, and its discharge amount increases or decreases in proportion to the rotational speed. However, the pressure compensated flow control valve 9 supplies a substantially constant flow of oil to the positive displacement hydraulic motor 7 regardless of the pressures before and after the valve. and,
Since the positive displacement hydraulic motor 7 has a rotational speed proportional to the supplied flow rate, its rotational speed does not change even if the load on the generator 11 changes.

That is, even if the water pressure supplied to the water turbine 2 fluctuates and the discharge pressure of the positive displacement hydraulic pump 6 fluctuates, the flow control valve 9 with pressure compensation
supplies a constant flow of oil to the positive displacement motor 7, so the rotational speed of the generator driven by the positive displacement hydraulic motor 7 maintains a substantially constant speed.

In the above case, the oil between the pressure-compensated flow control valve 9 and the hydraulic pump 6 may be at high pressure, but since there is a bypass pipe and safety valve 10, the pressure of the pipe is higher than the design value. protected from pressure.

FIG. 2 shows another embodiment. In this embodiment, another hydraulic motor 1a is provided in series with the hydraulic motor 7 that drives the generator, and the advertising billboard 12 is mechanically driven by this hydraulic motor 7a. This is how it was done.

In this embodiment as well, the rotational speeds of the hydraulic motors 7 and 7a are kept constant, so that the power supply from the power generator 111 and the driving of the billboard 12 are stable.

As described below, according to the present invention, pressure oil from a hydraulic pump driven by a water wheel is supplied to a hydraulic motor via a pressure compensated control valve. The rotational speed of the generator becomes stable, and the supply to the water turbine becomes stable.

[Brief explanation of the drawing]

Claims (2)

[Claims] (1) In a rotational speed control method for controlling the rotational speed of a small-output hydroelectric generator driven by a waterwheel without a rotational speed control device to a constant value, a hydraulic pump is driven by the waterwheel,
The oil discharged from the hydraulic pump is supplied to the hydraulic motor, the pressure oil supplied to the hydraulic motor is controlled by a flow control valve with pressure compensation, and the rotational speed of the hydraulic motor is controlled within a certain range using the controlled pressure oil. 1. A method for controlling the rotational speed of a generator using a driving force from a water wheel, the method comprising controlling the rotational speed of a generator using a driving force from a water wheel, and driving the generator using the hydraulic motor. (2) In a rotational speed control device that controls the rotational speed of a small-output hydroelectric generator driven from a waterwheel without a rotational speed control device to a constant value, a hydraulic pump driven by the waterwheel;
It consists of a hydraulic motor that receives oil discharged from the hydraulic pump, a flow control valve with pressure compensation installed in the oil passage between the hydraulic pump and the hydraulic motor, and a generator connected to the hydraulic motor. A generator rotation speed control device using driving force from a water turbine.