JP2007120314A - Power-saving method of water circulating compressor using inverter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power-saving method of a water circulating compressor driven by a motor using an inverter capable of reducing the motive power that reduces in response to a delivery quantity to an area of a low delivery quantity by reducing a rotating speed which suddenly increases an electric current when a use side air use quantity reduces. <P>SOLUTION: The purpose can be attained by supplying a small quantity of lubricating water by controlling opening-closing of a solenoid valve 2 and a throttling quantity of a throttle valve 3 by reducing the rotating speed of the motor 5 by the inverter 1 when the air use quantity reduces. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power-saving method for a water-circulating compressor driven by a motor, and more particularly, to a water-circulating compressor using an inverter that controls the rotational speed using an inverter and controls supply lubricating water. The present invention relates to a power generation method.

There are various types of water circulation type compressors, for example, “Patent Document 1”, and the conventional structure corresponding to the present invention is shown in FIG. 4 as a general structure.
JP 2000-205132 (FIG. 1)

  As shown in the figure, the air (outside air) that has passed through the air cleaner 7 is supplied to the compressor body 4 via the air capacity adjustment valve 15. The compressor body 4 is supplied with lubricating water. The lubricating water is supplied from the water supply unit 9 and the water 11 separated and stored in the receiver tank 10 is passed through a cooler 12 and a filter 14 and is solenoid-operated. Supplied via 2A. The compressed air compressed by the compressor is separated into air and water in the receiver tank 10, the air is sent to the air use side 13, and the separated water is collected in the receiver tank 10.

  In the water circulation type compressor configured as described above, when the amount of air used on the air use side is reduced, the air volume adjustment valve 8 is adjusted to adjust the supply air amount, and the rotation speed of the compressor is reduced to supply air from the compressor. I was trying to control the amount. In this case, the supply lubricating water can also be controlled.

FIG. 2 is a diagram showing the relationship between the rotational speed and current in the conventional compressor described above, and FIG. 3 shows the relationship between the air discharge amount and power. In the figure, a dotted line (B) is a conventional case.
In FIG. 2, the current increases as the rotational speed decreases, but the current rapidly increases at a certain rotational speed (indicated by “a”). On the other hand, when the air discharge amount is reduced in FIG. 3, the power is reduced accordingly, but the power reduction hardly occurs from the discharge amount (b).
The above phenomenon occurs in all of the conventional water circulation type compressors that control the compressor body 4 by the air capacity adjusting valve 8, and has been regarded as a problem when reducing the amount of air used.

  The present invention has been invented to solve the above-mentioned problems. When the amount of air used is reduced, the rotational speed at which the current rapidly increases is significantly lower than that of the conventional one, and the power is reduced as the discharge amount decreases. It is an object of the present invention to provide a power-saving method for a water circulation compressor using an inverter that reduces the degree of reduction to a lower discharge amount than before and thereby saves power as a whole.

  In order to achieve the above object, the present invention provides a power saving method at the time of air dose reduction in a motor-driven water circulation compressor that does not include an air capacity adjustment valve. The motor rotation speed is changed by inverter control corresponding to the amount of air used, and the flow rate of lubricating water supplied to the compressor is controlled.

  The invention according to claim 2 is characterized in that the flow control of the lubricating water is performed by opening and closing two electromagnetic valves arranged in the flow path and controlling the throttle valve.

  According to the power saving method of the water circulation type compressor using the inverter according to the first aspect of the present invention, when the air consumption is reduced, the rotational speed of the motor by the inverter is adjusted and the lubrication supplied accordingly. The flow rate of water is controlled, and this can solve the above problems.

  According to the power saving method of the water circulation type compressor using the inverter according to claim 2 of the present invention, the flow rate of the supplied lubricating water can be controlled by opening / closing the electromagnetic valve corresponding to the amount of air used and the throttle valve. It is performed by control, and lubrication water corresponding to low rotation can be supplied.

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a power saving method of a water circulation compressor using an inverter of the present invention will be described in detail with reference to the drawings.
The compressor body 4 is driven by a motor 5, and the motor 5 is rotationally controlled by an inverter 1. The inverter 1 is connected to a control unit 6 that controls the inverter 1 based on the amount of air used. Further, outside air is introduced into the compressor body 4 via an air cleaner 7. The compressor of the present invention is not provided with the air capacity adjustment valve 8 (FIG. 4) in the prior art. In addition, lubricating water is supplied to the compressor body 4, and the lubricating water is supplied from the water supply unit 9 and the water 11 stored in the receiver tank 10 by the cooler 12 and the filter 14 by the electromagnetic valve 2. Some are introduced through. Moreover, the electromagnetic valve 2 consists of two, the 1st electromagnetic valve 2a and the 2nd electromagnetic valve 2b, and the throttle valve 3 is provided in the 2nd electromagnetic valve 2b.

  The compressor main body 4 into which the outside air is introduced and the lubricating water is introduced is driven by the motor 5, and the compressed air is introduced into the receiver tank 10 where the air and water are separated. The air is sent to the air use side 13 for use, and the separated water 11 is sent to the cooler 12 side for circulation as described above.

When the amount of air used in the water circulation compressor having the above structure is reduced, the control unit 6 that detects this reduces the inverter 1 to control the number of rotations of the motor 5, and the compressor body 4 is driven at a low speed. In this case, unless the amount of lubricating water introduced into the compressor body is controlled as in the prior art, the supply of lubricating water increases in the compressor body 4 and smooth rotation cannot be achieved, and current and power are not reduced.
Therefore, in the present invention, when the engine speed is low, the first solenoid valve 2a is closed and the second solenoid valve 2b is opened, and the throttle amount of the throttle valve 3 is adjusted so that an appropriate amount of small amount of water is supplied to the compressor body 1. To supply. As a result, the motor can be operated at a lower speed than that of the prior art, and the current and power can be reduced.

  2 and 3 are a rotation speed-current diagram and a discharge amount-power diagram in the water circulation compressor of the present invention. 2 and 3, the solid line (A) indicates the present invention, and the dotted line (B) indicates the prior art as described above.

  In FIG. 2, in the prior art, when the rotational speed becomes point a or less, the current increases sharply. There is no rapid increase in current.

  In the case of the prior art in FIG. 3, the voltage decreases in proportion to the discharge amount until the discharge amount becomes a low discharge amount indicated by the point b. However, as shown by the dotted line (B), the discharge is performed below the point b. Even if the amount is reduced, there is little decrease in power. On the other hand, in the case of the present invention, it is a power-saving method of a water circulation compressor using an inverter, and as shown by a solid line (A), the power can be reduced even if the discharge amount becomes b point or less, and the discharge amount is reduced. Only when the discharge amount becomes lower than b> b ′, the reduction in power becomes loose.

  As described above, in the present invention, when the amount of air used is reduced, the current and power can be reduced to a lower rotational speed and lower discharge amount than in the prior art, and it is possible to save power at the time of low speed.

  Although the present invention has been described with respect to the water circulation compressor shown in FIG. 1, the type is not limited to that shown in the drawings, and is applicable to all types of water circulation compressors that are driven by a motor. .

The typical block diagram of the water circulation type compressor to which this invention is applied. The diagram which shows the relationship between rotation speed and an electric current. The diagram which shows the relationship between discharge amount and motive power. The typical block diagram of the conventional general water circulation type compressor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inverter 2 Solenoid valve 2a 1st solenoid valve 2b 2nd solenoid valve 3 Throttle valve 4 Compressor body 5 Motor 6 Control part 7 Air cleaner 8 Air capacity adjustment valve 9 Water supply supply part 10 Receiver tank 11 Water 12 Cooler 13 Air use Side 14 filter

Claims (2)

  A power saving method at the time of air volume reduction of a motor-driven water circulation compressor not provided with an air capacity adjustment valve, wherein the method changes the motor rotation speed by inverter control corresponding to the air usage amount and the compressor A method for reducing the power consumption of a water circulation compressor using an inverter, characterized in that the flow rate of lubricating water supplied to the inverter is controlled.   The power saving of the water circulation type compressor using the inverter according to claim 1, wherein the flow rate of the lubricating water is controlled by opening and closing two solenoid valves arranged in the flow path and controlling the throttle valve. Method.

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