JPH04241704A - Rotary fluid machine - Google Patents

Abstract

PURPOSE:To simplify a structure, to decrease a power transmission loss, and to reduce a space required for installation of a rotary fluid machine equipped with a blower or compressor, a turbine, and a motor. CONSTITUTION:An impeller 2 for a blower or compressor and a moving blade 10 for a turbine are directly attached to both ends of the shaft of a motor 26, which is able to operate as a generator as well respectively. In addition, the power source circuit of the motor 26 is provided with both a frequency converter 7, which changes the frequency of the alternating current from a commercial power supply 8 in order to supply the power to the motor 26, and a regenerative generating circuit 15 which converts the frequency of the alternating current, which is generated when the motor 26 operates as a generator, into another frequency.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary fluid machine comprising an improved blower or compressor and a turbine.

0002

2. Description of the Related Art FIG. 3 shows a conventional ultra-high speed motor directly connected blower. A blower impeller 2 is directly connected to the shaft of an ultra-high-speed electric motor 5, and the impeller 2 driven by the electric motor 5 converts air drawn from the blower's intake air pipe 1 into discharge air through the blower casing 3. It is designed to be discharged from piping 4. Reference numeral 7 denotes a frequency converter that converts the alternating current sent from the commercial power source 8 into an alternating current input having a frequency corresponding to the rotational speed of the electric motor 5 and supplies the converted alternating current to the electric motor 5.

FIG. 4 shows a conventional ultrahigh-speed motor-coupled turbine. A turbine rotor blade (impeller) 10 is directly connected to the shaft of an ultra-high-speed generator 13, and the turbine's intake steam piping 9
The generator 13 is driven by the steam supplied from the generator 13 to generate an AC output 14 of a frequency corresponding to the rotation speed of the generator 13, and this is converted into an AC output of a specific frequency, for example, 50Hz or 60Hz by the regenerative power generation circuit 15. I try to do that. 11 is a casing of the turbine, and 12 is a discharge steam pipe of the turbine.

FIG. 5 shows a conventional gas turbine generator. The air sucked into the compressor 2 from the intake air pipe 1 is pressurized and sent to the combustor 18, where it is mixed with fuel 17 and combusted to become combustion gas, which passes through the pipe 19 and is sent to the turbine 10. Sent. The turbine 10 generates rotational force to rotate the compressor 2 and the reduction gear 23. The reduction gear rotates the turbine 10 at 3000 rpm or 3600 r.
pm to drive the generator 24. The generator thus generates an alternating current 16 with a frequency of 50 Hz or 60 Hz. The required rotational force of compressor 2 at startup is external power supply 8.
, the turning device 25 is rotated. 22 is a shaft coupling, 20 is a connecting shaft, and 21 is a turbine exhaust gas pipe.

[0005]

[Problems to be Solved by the Invention] Conventionally, a blower or compressor is often used with an electric motor, and a turbine is often used with a generator. , electric motors (or generators) each have a rotor,
Bearings and shaft couplings are required, resulting in a complex structure and large power transmission loss. Furthermore, centering of the shaft coupling and checking of the tooth surface of the gear are also required, which is complicated. The problem is that the overall installation space is larger compared to the blower and turbine itself.

[0006] The present invention aims to eliminate the above-mentioned disadvantages of conventional rotating machines.

[0007]

[Means for Solving the Problems] 1 The rotary fluid machine of the present invention has an impeller of a blower or compressor and a rotor blade of a turbine directly attached to each of both shaft ends of an electric motor that can also be operated as a generator. , and the power supply circuit of the motor includes a frequency conversion circuit that converts the frequency of the commercial power supply to AC of any frequency and supplies the motor with controllable rotation speed, and a frequency conversion circuit that converts the frequency of the commercial power supply to AC of any frequency and supplies the rotation speed to the motor so that the rotation speed can be controlled. The regenerative power generation circuit is configured to have a regenerative power generation circuit capable of converting the generated alternating current frequency into alternating current having another frequency and outputting the converted alternating current.

[0008] Furthermore, the present invention provides the rotary fluid machine of the above 1, which has a flow path for guiding the fluid pressurized by the blower or compressor to the turbine via a temperature raising device such as a combustor or a heat exchanger. It is configured as follows.

[0009]

[Operation] In the first aspect of the present invention, the blower or compressor and the turbine are directly connected to the shaft of an electric motor which can also be operated as a generator. When the power required by the blower or compressor exceeds the power generated by the turbine, the electric motor is driven by alternating current supplied by the frequency conversion circuit to compensate for the power shortage. In addition, when the required power of the blower or compressor is less than the power generated by the turbine, the electric motor becomes a generator and generates power, and the generated alternating current is converted to another predetermined frequency by the regenerative power generation circuit. is output.

Furthermore, as mentioned above, the blower or compressor and turbine are directly connected to the shaft of the electric motor, eliminating the need for a conventionally required power transmission mechanism such as a shaft coupling, resulting in a simple structure and a simple structure for power transmission. There is no loss, there is no need to center shaft couplings, etc., and the installation space is small.

In the second aspect of the present invention, the fluid whose pressure has been increased by the blower or compressor is passed through a temperature raising device such as a combustor or a heat exchanger to increase the volume of the fluid and increase the turbine output by increasing the pressure of the fluid by the blower or compressor. It can be more than the compressor input.

0012

Embodiment A first embodiment of the present invention will be explained with reference to FIG. A blower or compressor (hereinafter abbreviated as a blower) is installed at each of both shaft ends of an ultra-high speed variable speed electric motor 26 which takes the form of an inverter panel and is driven by AC being supplied from a frequency converter 7 connected to a commercial power source 8. An impeller 2 and a rotor blade 10 of a radial turbine are directly attached, and a frequency converter 7 is connected to a regenerative power generation circuit 15.

The frequency conversion device 7 is configured to receive alternating current from a commercial power source 8, convert the frequency appropriately and supply the alternating current to the electric motor 26, thereby controlling the rotational speed of the electric motor 26. The power generation circuit 15 includes an electric motor 26
When it operates as a generator, it receives alternating current at a frequency that is generated depending on its rotational speed, and converts this into alternating current at another frequency.
6. For example, it is configured to convert into alternating current at a frequency of 50 Hz or 60 Hz of a commercial power source and output it. The radial turbine is also supplied with steam generated from a heat source such as surplus heat from a plant (not shown).

In FIG. 1, 1 is a blower suction pipe, 3 is a blower casing, 4 is a blower discharge pipe, 9 is a radial turbine suction steam pipe, 11 is a radial turbine casing, and 12 is a radial turbine discharge steam. 27 indicates an alternating current flowing from the frequency converter 7 to the electric motor 26 or vice versa.

In this embodiment configured as described above, air sucked in from the suction pipe 1 of the blower is compressed by the impeller 2 of the blower and then discharged from the discharge pipe 4. Steam generated by surplus heat of the plant and the like and sucked in from the intake steam pipe 9 of the radial turbine is discharged from the discharge steam pipe 12 after doing work in the radial turbine.

When the power required for the blower exceeds the power generated by the turbine, the power is obtained from the commercial power source 8 and the electric motor 2
6 covers the insufficient power, and when the required power of the blower is less than the generated power of the turbine, the electric motor 26 becomes a generator and generates alternating current at a frequency according to changes in its rotational speed, and the regenerative power generation circuit 15 converts this into AC 16 of 50 Hz or 60 Hz, which is the frequency of a commercial power supply, or another frequency, and can extract electric power.

Furthermore, in this embodiment, the impeller 2 of the blower and the rotor blades 10 of the radial turbine are directly connected to the shaft of the electric motor 26, eliminating the need for power transmission mechanisms such as shaft couplings that were conventionally required. The structure is extremely simple, there is no power transmission loss, there is no need to center joints, etc., and the installation space can be reduced.

Although the first embodiment uses a radial turbine to drive the blower, other types of turbines may be used.

A second embodiment of the present invention will be explained with reference to FIG. This embodiment is obtained by adding the following parts to the first embodiment. That is, the blower discharge pipe 4
was branched and connected to the combustor 18, the fuel pipe 17 was connected to the combustor 18, and the combustion gas pipe 19 of the combustor 18 was connected to the casing 11 of the radial turbine.

In this embodiment, part or all of the air discharged from the discharge pipe 4 of the blower is transferred to the fuel pipe 17 in the combustor 18.
The heated combustion gas is mixed and combusted with the fuel from the combustion gas pipe 19, is guided to the radial turbine, is sucked into the turbine, and is used to drive the blower and generate electricity as in the first embodiment. I do.

In this manner, in this embodiment, the air pressurized by the blower is further heated to increase its volume, and the output of the turbine can be increased beyond the input of the blower.

[0022] In the second embodiment, the air pressurized by the blower is heated by the combustor, but it may also be exchanged with a waste heat source of the plant such as exhaust gas.

[0023]

[Effects of the Invention] The rotary fluid machine of the present invention according to claim 1 is constructed as described above, and since the conventional power transmission mechanism is eliminated, power loss is eliminated and power transmission efficiency is improved. , the moment of inertia is reduced, the drive system mechanism is simplified, harmful vibrations are reduced, shaft coupling centering is no longer required, and installation space is reduced.
The amount of lubricating oil decreases. Furthermore, since the electric motor and generator are the same, smooth switching can be performed, and with only one rotor, the structure can be made simple, small and lightweight.

[0024] Furthermore, the rotary fluid machine of the present invention according to claim 2, in addition to the present invention according to claim 1, is characterized in that the fluid pressurized by the blower or compressor is guided to the upper turbine where the temperature is further raised. , the turbine output can be made larger than the blower or compressor input.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of a first embodiment of the present invention.

FIG. 2 is a schematic explanatory diagram of a second embodiment of the present invention.

FIG. 3 is a schematic explanatory diagram of a conventional ultra-high-speed electric motor direct-coupled blower.

FIG. 4 is a schematic explanatory diagram of a conventional ultrahigh-speed generator direct-coupled turbine.

FIG. 5 is a schematic explanatory diagram of a conventional gas turbine generator.

[Explanation of symbols]

1 Blower intake air piping 2 Blower impeller 3 Blower casing 4 Blower discharge air piping 7 Frequency converter 8 Commercial power supply 9 Turbine intake steam piping 10 Radial turbine rotor blades 11 Radial turbine casing 12 Turbine discharge steam Piping 15 Regenerative power generation circuit 16 AC output 17 Fuel piping 18 Combustor 19 Combustion gas piping

Claims (2)

[Claims] Claim 1: The impeller of a blower or compressor and the rotor blades of a turbine are directly attached to each of the shaft ends of an electric motor that can also be operated as a generator, and the power supply circuit of the electric motor is connected to the frequency of the commercial power source. A frequency conversion circuit that converts AC of any frequency into AC of any frequency and supplies it to the motor so that the rotation speed can be controlled.When the motor operates as a generator, the AC of a frequency generated according to the rotation speed is converted to AC of other frequencies. A rotary fluid machine characterized by having a regenerative power generation circuit capable of converting and outputting. 2. The rotary fluid machine according to claim 1, further comprising a flow path for guiding the fluid pressurized by the blower or the compressor to the turbine via a temperature raising device.