WO2017130303A1

WO2017130303A1 - Gas compressor and gas compressor system

Info

Publication number: WO2017130303A1
Application number: PCT/JP2016/052224
Authority: WO
Inventors: 山本　健太郎; 正彦高野
Original assignee: 株式会社日立産機システム
Priority date: 2016-01-27
Filing date: 2016-01-27
Publication date: 2017-08-03
Also published as: JPWO2017130303A1; JP6595008B2

Abstract

To generate regenerative power by means of a gas compressor using gases discharged from the gas compressor and other apparatuses. Disclosed is a gas compressor having a compressor main body that generates a compressed gas by sucking a gas. The gas compressor has: a rotating electrical machine, which is an electric motor that drives the compressor main body by receiving power supply, and which is also a power generator that generates regenerative power by obtaining power from the compressor main body; an inverter that controls the rotation number of the rotating electrical machine by changing the frequency of the power supply; a converter that generates output power from the power thus generated; and a check valve that allows, on a discharge-side pipe of the compressor main body, circulation of compressed air from the compressor main body side to the compressor discharge side. When driving of the compressor main body is stopped, the compressor main body reversely rotates due to the fact that compressor air in the upstream of the check valve reversely flows, and the gas compressor generates power for generating the regenerative power.

Description

Gas compressor and gas compressor system

The present invention relates to a gas compressor and a gas compressor system, and relates to a gas compressor and a gas compressor system for regenerating energy.

It is said that the energy consumed by a gas compressor such as an air compressor out of the energy consumed by the entire factory etc. is equivalent to 20 to 25%, and the effect on energy saving of the gas compressor is great.

In recent years, as a matter of course, the performance of the gas compressor device itself has been improved, and in addition to energy saving from the drive control surface using an inverter for a gas (for example, air) compressor, exhaust heat generated during compression is recovered and heating is performed. Efforts are also being made to use it for hot water, use hot water, and preheat water for boilers.

Patent Document 1 discloses a configuration in which high-temperature compressed air discharged from a gas compressor main body and heat of lubricating oil that performs lubrication of the gas compressor main body and cooling of the compressed gas are heat-exchanged, and power is generated by a Rankine cycle. Is disclosed.

In addition, the electric motor (motor) used as a drive source which drives a gas compressor main body is a rotary electric machine which functions as a generator (generator) by making it reverse. Patent Document 2 discloses a positive displacement screw expander as a steam expander (expander) for expanding steam as means for reversing the electric motor. Patent Document 2 discloses a configuration in which expansion of steam supplied from a steam supply system such as a boiler is converted into rotational force by a screw expander, and this is used as a drive source for a generator.

JP 2011-12659 A Japanese Patent No. 5148117

By the way, in general, as the gas compressor, there are known a variable speed controller for controlling the motor at a variable speed by mounting an inverter and a constant speed controller for operating the motor at a constant speed. From the viewpoint of energy saving, in the capacity control of constant speed controllers, there are those that perform load / unload operation control that repeats load operation and no-load operation according to the amount of gas used by the user, etc., and also automatic stop control etc. is there. On the other hand, in the capacity control of the variable speed controller, energy can be saved by variable speed control using an inverter in addition to these.

In such control, during unloading operation or automatic stop, the compressed gas in the compressor internal piping system is discharged to the atmosphere to reduce the pressure, thereby reducing the load on the motor that is the driving source, thereby obtaining an energy saving effect. .

However, since the released compressed gas is discarded, if the discharged gas can be used effectively, this will lead to energy saving of the gas compressor.

In order to solve the above problems, for example, the configuration described in the claims is applied. That is, a gas compressor having a compressor main body that sucks gas and generates compressed gas, and is an electric motor that drives the compressor main body by receiving supply power, and obtains power from the compressor main body and regenerates electric power. A rotating electrical machine that is a generator for generating the power, an inverter that controls the rotational speed of the rotating electrical machine by changing the frequency of the supplied power, a converter that generates output power from the generated power, and a compressor body A check valve that permits the flow of compressed air from the compressor body side to the discharge side on the discharge side piping, and when the compressor body stops driving, the compressor air upstream from the check valve is It is a gas compressor that generates power for generating regenerative power by reversely rotating the main body of the compressor by reverse flow.

Another configuration is a gas compressor system including a plurality of gas compressors having a compressor body that sucks gas and generates compressed gas, and at least one gas compressor of the plurality of gas compressors A is an electric motor that receives supply power and drives the compressor body, and a rotating electrical machine that is a generator that generates regenerative power by obtaining power from the compressor body, and changes the frequency of the supply power to change the frequency Permits the flow of compressed air from the compressor body side to the discharge side on the inverter that controls the rotation speed of the rotating electrical machine, the converter that generates output power from the generated power, and the discharge side piping of the compressor body A check valve that communicates with a discharge pipe path from the discharge side of the compressor body to the upstream of the check valve, and an external intake pipe that takes in compressed air from one or more other gas compressors B And before At the time of standby of the compressor body, the compressor body reversely rotates by the compressor air taken in from the external intake pipe, and generates power for generating the regenerative power, and the gas compressor B is An electric motor that drives the compressor body, a check valve that permits the flow of compressed air from the compressor body side to the discharge side on the discharge side piping of the compressor body, and compressed air upstream from the check valve The gas compressor system has an air discharge pipe installed on the air discharge pipe, and the gas compressor system is disposed downstream from the air discharge valve of the gas compressor B and the gas compressor. A external intake pipe of A communicates, and is connected to be able to communicate with the plurality of gas compressors, and when the gas compression A is on standby and the gas compressor B is venting, the vent valve is Gas compressor system having a control device for opening It is.

According to one aspect of the present invention, a gas compressor that generates compressed gas can also be used as a device that generates regenerative energy using surplus gas, thereby improving the energy saving effect.

Further, according to one aspect of the present invention, in a gas compressor system including a plurality of gas compressors, regenerative energy can be generated by the other gas compressor using the discharged gas of one gas compressor. , Energy saving can be achieved in the entire system.
Other problems, configurations, and effects of the present invention will become apparent from the following description.

It is a schematic diagram which shows the structure of the air compressor by Example 1 to which this invention is applied. 3 is a timing chart illustrating the operation flow of the air compressor according to the first embodiment. It is a schematic diagram which shows the structure of the air compressor system by Example 2 to which this invention is applied. 6 is a flowchart illustrating a flow of processing of a number control unit according to the second embodiment.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 schematically shows a configuration of an oil supply type air compressor 100 according to an embodiment to which the present invention is applied. In this embodiment, an oil supply type air compressor that takes in air and discharges compressed air is illustrated, but the present invention is not limited to this, and the type and supply of gas to be compressed are within the scope of the present invention. It can also be applied to a liquid (water etc.) type compression device.

The air compressor 100 includes a compressor body 5 that compresses air taken in through the air filter 1 and the suction throttle valve 2 from the outside, a rotating electrical machine 6 that serves as a drive source and a power generation source of the compressor body, and discharge mixing. A temperature sensor that detects the temperature of the gas, an oil separator 9 that primarily separates compressed air and lubricating oil from the discharged mixed gas, an element 10 that further separates oil from the separated compressed air, and a secondary separation. A pressure regulating check valve 11 disposed on the compressed air discharge piping path, and a heat exchanger 13 for cooling the compressed air and the lubricating oil described later with cooling air from the fan 14 through the check valve 11; Unlike the discharge pipe, the control pipe system disposed on the downstream side of the oil separator 9 and the air discharge solenoid valve 17, the operation solenoid valve 18 and the regeneration valve respectively disposed on the three pipes branched from the air discharge pipe system. Solenoid valve 19 and regenerative An ejection valve 3 disposed downstream of the magnetic valve 19, an ejection element 4 disposed downstream of the ejection valve 3, and a recovery mechanism for returning the lubricating oil removed by the ejection element 4 to the compressor body 5 ( An oil receiver 40, a check valve 41), a control panel 27 for controlling the rotating electrical machine 6, the fan motor 15 and various electromagnetic valves, a fan inverter 16 for converting the frequency of electric power supplied to the fan motor 15, An external housing (package) 23 for storing these is provided as a main component.

Compressed air generated by the air compressor 100 is temporarily stored in an external tank (reservoir tank) 45 and then sent to a user device. In addition, you may make it send compressed air directly to a user side apparatus, without installing the external tank 45. FIG.

The compressor body 5 is a screw type compressor composed of one or a plurality of screw rotors. The compressor body 5 and the rotating electrical machine 6 are configured so that the rotor and the motor shaft are in the same axis (in a divided or integrated configuration). Being on the same axis can reduce opportunity loss and contribute to efficient compression and efficient power generation. The present invention can also be applied to other types of compressor bodies and other connection configurations.

The oil separator 9 has a lubricating oil passage 30 for returning the lubricating oil accumulated at the bottom thereof to the compressor body side. The lubricating oil path 30 is branched into two systems on the downstream side via the temperature control valve 12 in the middle. One is a reflux path that directly communicates with the compressor body 5, and the other is a path that is connected to the reflux path after passing through the heat exchanger 13. The temperature control valve 12 is a valve that switches the flow path of the lubricating oil with the lubricating oil temperature as a threshold. When the lubricating oil temperature is lower than the threshold, the path that directly recirculates to the compressor body 5 is opened, and vice versa. If it is higher than the threshold, the flow path is switched with the path connected to the heat exchanger 13 opened. For example, if the discharge air temperature is low immediately after startup or the like, and the drain generation limit temperature is low, lubricating oil is circulated through a path that does not flow into the heat exchanger 13 to increase the discharge temperature in order to prevent drain generation. . On the contrary, when it is higher than the drain generation limit temperature, it is switched to a path flowing into the heat exchanger 13 so that the discharge temperature does not rise any further. The lubricating oil that has circulated through one of the paths then returns to the compressor body 5 through the oil filter 20.

The heat exchanger 13 is a cooler that exchanges heat between the separated compressed air and the lubricating oil with the cooling air generated by the fan 14. The control unit 26 changes the rotation speed of the cooling fan by the fan inverter 16 and the fan motor 15 according to the detection value of the temperature sensor 25 that detects the temperature of the discharge air discharged from the compressor body 5. It has become.

The control piping system 31, which is connected to the downstream side of the element 10 that performs secondary separation of the lubricating oil and is different from the discharge piping system that leads to the user side, has a compressed air discharge path, a suction throttle valve 2, and the like. It functions as a path for supplying the drive control pressure of the ejection valve 3.

When the drive of the compressor body 5 is an unload operation, the discharge air solenoid valve 17 discharges the compressed air between the pressure check valve 11 and the compressor body 5 to reduce the pressure, and drives the rotating electrical machine 6. The power is reduced. More specifically, the control unit 26 “closes” the operation solenoid valve 18 and the regenerative solenoid valve 19 and “opens” the release solenoid valve 17 to perform external release.

The operation solenoid valve (suction throttle valve control device) 18 is “open” during the load operation, the suction throttle valve 2 is opened, and the outside air is sucked into the compressor body 5. The operation solenoid valve 18 is “closed” when the compressor main body 5 is automatically stopped, and the suction throttle valve 2 having a biasing force in the closing direction is closed by a spring or the like, so that the compressor main body 5 is closed. Prevent outside air from circulating. Opening and closing of the operation control valve 18 is controlled by the control unit 26.

The regenerative solenoid valve (valve element control device) 3 is “closed” in the load operation or unload operation, and as a result, the ejection valve 3 prohibits the communication between the ejection element 4 side and the intake path. . In the automatic stop operation, the regenerative solenoid valve 3 is “open”, and the ejection valve 3 permits communication between the ejection element 4 side and the intake path. The opening and closing of the regenerative solenoid valve 3 is controlled by the control unit 26.

The suction pipe path through which the air sucked through the suction throttle valve 2 flows into the compressor main body 5 is branched into two, one connected to the compressor main body 5 and the other for ejection (oil). It is connected to the element 4 and the oil recovery mechanism. The air flow to the other path is controlled by the regenerative solenoid valve 3 as described above. During regenerative operation using air discharge described later, the compressed air that flows backward from the suction side of the compressor body 5 is a mixed gas of air and lubricating oil, so an oil recovery mechanism is provided to provide an inside or outside of the lubricating oil housing. To prevent splashing.

The oil recovery mechanism includes an oil receiver 40 and a check valve 41. The ejection element 4 separates oil and air from the compressed air flowing backward from the compressor body 5 side during the regenerative operation, and the separated oil passes through an oil receiver 40 and a check valve 41 installed at the drop destination. Thus, the refrigerant is returned to the suction pipe path. During the regenerative operation, the suction pipe path side is at a high pressure, and the oil does not recirculate from the upstream side of the check valve 41. The system is allowed to recirculate lubricating oil.

The control unit 26 is a control function unit realized by the cooperation of an arithmetic device such as a CPU or MPU and a program, and outputs various control commands to the solenoid valve, the inverter 7, the converter 8, and the fan inverter 16. . Further, the control unit 26 includes a memory (not shown), and can store or set an air discharge pressure, various control threshold values, and the like that are externally input via an operation panel or a network (not shown).

The air compressor 100 has a pressure sensor 28 as a pressure detection device on the user side discharge piping path downstream from the pressure regulating valve 11. The pressure sensor 28 detects the compressed air pressure on the user side (equipment machine, reservoir tank, etc.). The control unit 26 outputs a control command to the inverter 7 according to the detection value of the pressure sensor 28, and executes inverter control operation, load operation, unload operation, and automatic stop operation.

Here, the inverter control operation is control for changing the output frequency value of the inverter based on the detection value of the pressure sensor 28 so that the discharge pressure on the user side maintains a predetermined set discharge pressure. For example, if the user-side discharge pressure is equal to or higher than the set pressure, the output frequency is reduced and the rotational speed of the compressor body 5 is reduced. Conversely, when the pressure falls below the set pressure, the output frequency is increased to increase the rotational speed of the compressor body 5.

In the unload operation, for example, when the air usage amount on the user side decreases and the user side pressure reaches a predetermined upper limit pressure higher than the set discharge pressure, the air release solenoid valve 17 is opened and the operation electromagnetic In this operation, the valve 18 is set to “closed”, the rotational speed of the rotating electrical machine 6 is further reduced, and the drive power of the compressor body 5 is saved. Examples of the degree of decrease in the rotational speed include, but are not limited to, a minimum rotational speed that can generate a pressure necessary for the lubricating oil to flow through the lubricating oil passage 30. In addition, although the suction throttle valve 2 is “closed”, the discharge side of the compressor body 5 can generate an environment whose pressure is higher than the atmospheric pressure by the air slightly sucked from the valve closing gap or the like.
Thereafter, when it is detected that the air usage amount on the user side has increased to a value close to the set discharge pressure, the air discharge electromagnetic valve 17 is closed and the compression on the upstream side of the pressure regulating check valve 11 is resumed. In addition to this, the rotation speed of the rotating electrical machine 6 is increased, and the user side is maintained at a set discharge pressure or higher with the upper limit pressure as a limit. In addition, when the user side pressure falls to a predetermined lower limit pressure lower than the set discharge pressure, it is preferable to switch to the load operation.

The load operation is an operation in which the rotary electric machine 6 is driven at a rating while the discharge valve 17 is kept “closed” and the operation solenoid valve 17 is kept “open” until the set discharge pressure is reached. The present invention is applicable even when the suction throttle valve 2 and the operation solenoid valve 16 are not included in the configuration.

The automatic stop operation is an operation in which the drive of the compressor body 5 is temporarily stopped when, for example, the user side air consumption decreases and the state where the user side pressure is equal to or higher than the set discharge pressure continues for a predetermined time. . For example, when the air usage on the user side decreases, the user side pressure becomes equal to or higher than the set discharge pressure, and eventually reaches the upper limit pressure, the control unit 26 performs the unload operation. Is temporarily stopped (the power supply to the rotating electrical machine 6 is stopped), and the passage of a predetermined time and the user-side pressure are set to a predetermined pressure (for example, a lower limit in unload operation). In some cases, it is more efficient in terms of energy saving when the driving is restarted when the pressure becomes lower than a return pressure lower than the pressure.

Therefore, in this embodiment, when the state of the set discharge pressure or more continues for a predetermined time, the power supply to the rotating electrical machine 6 is stopped to save power. The pressure reference for starting the automatic stop operation is not limited to the set discharge pressure, and may be an arbitrary pressure such as an upper limit pressure. Further, the duration of the predetermined pressure state is not limited to the start timing of the automatic stop operation, but the control unit 26 monitors and calculates the ratio of the unload operation and the load operation per unit time interval, and the ratio of the unload operation Various modes may be applied, for example, an automatic stop operation is performed when becomes large. Further, in the embodiment, an example in which the unload operation is executed before the automatic stop operation will be described, but the present invention can be applied even if the unload operation is not necessarily assumed as the automatic stop operation.

Next, the regenerative operation function will be described with reference to FIG.
As described above, during the automatic stop operation, the rotation of the compressor body 5 is temporarily stopped (power supply to the rotating electrical machine 6 is stopped), but on the downstream side from the pressure regulating check valve 11, the compressor body 5 is discharged to the discharge side. On the other hand, a back pressure is generated by backflow. At the time of unloading operation, the back pressure is eliminated by venting outside through the venting solenoid valve 17, but at the time of regenerative operation, the venting solenoid valve 17 is set to “closed” and downstream from the pressure regulating check valve 11. The compressed air is caused to flow backward to the compressor body 5. The screw rotor of the compressor body 5 functions as a generator by rotating in reverse by the compressed air flowing backward, and the rotating electric machine 6 also rotating in reverse. Electricity generated by the reverse rotation of the rotating electrical machine 6 can be used as regenerative power by the converter 8. As described above, the compressed air discharged from the suction side of the compressor body 5 to the suction piping path is then discharged to the outside of the piping system.

The regenerative power is used as power for the fan motor 15 that drives the cooling fan 14. Since the regenerative electric power is generated using the discharged air, this is equivalent to the fact that there is no compressed air generated by the compressor body 5 during an automatic stop operation or the like. Since there are few factors that increase the lubricating oil, the rotation speed of the cooling fan may be relatively low. For this reason, the generated power can be generated only during the time during which the discharged air is released, but sufficient power can be obtained when a cooling environment with a low load is sufficient.

In the present embodiment, an example in which power is used for a fan motor will be described. However, the present invention is not limited to this example. Is possible.

A flow of such a series of operations will be described.
The time t0 indicates a state in which the rotating electrical machine 6 is driven at a rating and the user-side pressure is set discharge pressure. At this time, the load factor of the rotary electric machine 6 is 100% (rated), the operation solenoid valve 18 is “open (that is, the suction throttle valve 2 is open)”, the air release solenoid valve 17 is “closed”, The electromagnetic valve 19 is in a “closed” state (in an inverter control operation), and a load operation is performed. In the drawing, the “rotation direction” is the rotation direction of the rotating electrical machine 6, and the rotation direction during compression is “forward rotation”.

At time t1, when the control unit 26 detects that the user-side discharge pressure has reached the upper limit value, it starts the unload operation. That is, a frequency reduction command (for example, the minimum rotation frequency) is output to the inverter 7 to reduce the load factor of the rotating electrical machine 6. Similarly, the control unit 26 “closes” the operation solenoid valve 18 and “opens” the air release solenoid valve 17 to restrict the intake of air and reduce the pressure in the piping system upstream from the pressure regulating check valve 11. . Thereby, the load factor of the rotary electric machine 6 further decreases. Thereafter, the user-side discharge pressure gradually decreases according to the user-side air consumption.

When detecting that the user-side discharge pressure has reached the lower limit value set to the same value as the set discharge pressure at time t2, the control unit 26 switches from the unload operation to the load operation. Note that the load operation at this time is a load operation performed by controlling the air discharge electromagnetic valve and the operation control valve while the load factor of the rotating electrical machine 6 is reduced.
The control unit 26 “opens” the operation solenoid valve 18 and “closes” the discharge solenoid valve 17, and boosts the piping system upstream from the pressure regulating check valve 11. That is, by using the rotation of the rotating electrical machine 6 at a low load factor, the pressure is increased by increasing the suction amount and limiting the air discharge amount.

At time t3, when the control unit 26 detects that the user-side discharge pressure has reached the upper limit value, it again sets the operation solenoid valve 18 to “closed” and the air release solenoid valve 17 to “open”. That is, the operation state is the same as the unload operation at time t1. When the control unit 26 detects again that the user-side discharge pressure has reached the lower limit value at time t4, the solenoid valve is controlled to increase the pressure again similarly to time t3. In this embodiment, the trigger for switching from the unload operation to the load operation is described as the upper limit pressure, but in addition to this, any pressure between the set discharge pressure and the upper limit pressure may be used as the trigger for switching. . This is because if the installation value of the upper limit pressure is relatively high, it may take a considerable amount of time to increase the pressure to the pressure during unload operation.

As described above, the air compressor 100 repeats the unload operation and the load operation based on the user-side discharge pressure, but the control unit 26 activates the timer simultaneously with the detection of the upper limit pressure, and then sets the lower limit pressure. When the elapse of a predetermined time or the like is detected before reaching, the execution of the automatic stop operation is started.

At time t5, when the control unit 26 detects a predetermined elapsed time, the operation solenoid valve 18 is “open” and the discharge solenoid valve 17 is “closed” to increase the user-side discharge pressure to the upper limit value. At this time, if necessary, the rotational speed of the rotating electrical machine 6 may be increased. That is, before the compressor main body 5 is stopped, the user side pressure is controlled to be high. The automatic stop function occurs when the user side air consumption is considerably low or absent for a predetermined elapsed time. For example, high-pressure compressed air filled in a reservoir tank or user equipment is cooled by natural heat dissipation or the like. Then, drainage may occur. In addition, there is also an advantage that when the user starts using again, a pressure higher than the set discharge pressure can be obtained immediately. Furthermore, since the inside of the piping system of the air compressor 100 becomes substantially atmospheric pressure due to the automatic stop operation, it takes time to obtain the pressure up to the set discharge pressure even if it is re-driven due to an increase in the amount of air used. It depends on the reason.

At time t <b> 6, when the control unit 26 increases the pressure again to the upper limit pressure, the control electromagnetic valve 18 is “closed”, but the air release electromagnetic valve 17 is kept “closed”. Then, after the operation solenoid valve 18 is “closed”, the regenerative solenoid valve 19 is “open”. As a result, compressed air flows backward from the piping system upstream from the pressure regulating check valve 11 to the discharge side of the compressor body 5, and power generation by the rotating electrical machine 6 is started. In addition, after the operation solenoid valve 18 is “closed” (several seconds), the regenerative solenoid valve 19 is “opened”, so that the backflow compressed air containing a relatively large amount of oil is introduced into the suction throttle valve 2 and upstream thereof. It is possible to reliably prevent distribution.
After the automatic stop operation, the load operation (by the inverter control operation) is resumed at a predetermined elapsed time or an arbitrary redrive start pressure.

In the present embodiment, the control mode in which the unload operation is performed has been described. However, even if there is no unload operation and the combination control mode includes only the inverter control operation and the automatic stop operation, The present invention can be applied if the electric machine 6 can be reversed. Further, in the present embodiment, the example in which the automatic stop operation increases the pressure to the upper limit value before the stop has been described, but it is also possible to configure so that the air is released without increasing the pressure.

As described above, according to the present embodiment, regenerative power can be obtained using air to be discharged (discarded). Further, since the compressor body itself is used for the compression means and the expansion means, and the rotating electric machine is used for the electric motor and the generator, the usability as a device is remarkably increased.
Further, in this embodiment, boosting before the automatic stop operation is performed from the viewpoint of preventing the occurrence of drain on the user side and usability at the time of resuming air use. However, further power can be obtained using this boosted pressure, and air compression is performed. Excellent effect on machine convenience and energy loss reduction.
In addition, the valve control on the suction piping path side associated with the regenerative operation prevents oil scattering in the external housing 23 or the surrounding external environment, and has both maintenance and environmental effects.

The first embodiment is an example in which regenerative electric power is generated by causing the compressed air in the air compressor 100 to flow backward to the compressor body 5, but the second embodiment uses the air discharged from another air compressor. This is a configuration example for generating electric power. Hereinafter, Example 2 will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the component similar to Example 1, and detailed description is abbreviate | omitted.

FIG. 3 schematically shows a configuration of an air compressor system 300 according to the second embodiment. The air compressor system 300 includes the air compressor 100 according to the first embodiment and the air compressor 200. The air compressor system 300 is a compressor system that enables control of a plurality of units according to the amount of air used, for example. Both units are driven, one is driven and the other is stopped (compressor) under the control of the number control unit 50 connected to each of the

control units

26A and 26B in a wired or wireless manner (including network connection such as the Internet). Various operations such as a stand-by state in which the main body 5 stops driving) or both stop are enabled.

The number control unit 50 is realized by the cooperation of an arithmetic device such as a CPU or MPU and a program. In the present embodiment, the number control unit 50 is installed outside the

air compressors

100 and 200, but may be configured to be mounted on the control panel 27 or the like of any of the air compressors.

The main difference between the air compressor 100 and the first embodiment is that the air discharged from the air compressor 200 is taken into the discharge pipe connected to the oil separator 9 from the compressed air main body 5. It is a point provided with intake piping (external intake piping) 22. The discharge air intake pipe 22 is provided with a three-way solenoid valve 60. When the air compressor 100 is in an unload operation or automatic stop operation (in a state where the regenerative operation cannot be performed), the air from the air compressor 200 is supplied. Inhalation air intake is prohibited, and distribution to a route on the outside emission side is permitted. When the three-way solenoid valve 60 is in a state in which the regenerative operation is possible, the flow on the external discharge side is prohibited and the intake of the discharge air from the air compressor 200 is permitted.

The air compressor 200 is an oil supply type screw compressor. Each configuration for generating compressed air is the same as that of the air compressor 100, but does not include elements (converter 8, regenerative solenoid valve 19, converter 8, oil recovery mechanism, etc.) that generate regenerative power. Here, the air compressor 200 is also provided with an element for generating line power, and the air discharged from each of the

air compressors

100 and 200 can be used by connecting the air discharge pipe and the intake pipe. It is also possible to make it possible to generate electricity with a machine.

In addition, the air compressor 200 is not limited to the air compressor 200 which is an oil supply type screw compressor, and may be other oil supply type or non-oil supply type compressors such as a vane, a scroll, a reciprocator, and the like.

The air discharge pipe system of the air compressor 200 is connected to the air discharge air intake pipe 22 of the air compressor 100. For example, when the air compressor 200 is driven and the air compressor 100 is stopped (standby), the compressor body 5 of the air compressor 100 is in a state in which it can be reversed. Therefore, the air compressor 200 discharges the air discharged during the unload operation and the automatic stop operation to the air compressor 100 side, and the air compressor 100 generates power. In the first embodiment, power generation can be performed only by the air discharge during the automatic operation, but the second embodiment has a specific effect that the air discharge during the unload operation can also be used.

In the second embodiment, the compressed air generated by the air compressor 100 is temporarily stored in the external tank 45A as in the first embodiment. The compressed air generated by the air compressor 200 may be temporarily stored in the external tank 45A or may be stored in another external tank 45B. Furthermore, you may make it supply compressed air directly to the apparatus by the side of a user, without using an external tank.

In such a configuration, the discharged air intake pipe 22 of the air compressor 100 may be connected to the

external tanks

45A and 45B and the user side device. By regenerating these surplus compressed air, more regenerative electric power can be obtained. In particular, the compressed air temporarily stored in the external tank 45B may release the stored air when, for example, the use of the day ends. For example, when the time until reuse becomes long, drainage may occur in the tank due to the temperature if the pressure remains high.

Fig. 4 shows the processing flow of the air compressor system. This process is executed by the number control unit 50 and the

control units

26A and 26B of the

air compressors

100 and 200.

In S101, the unit control unit 50 determines whether the air compressor 100 is stopped driving or is on standby, and whether the air compressor 200 is driving (including load operation and unload operation). If there is (S101: Yes), the process proceeds to S103, the three-way solenoid valve 50 is set to "open", and the air discharge pipe system of the air compressor 200 and the discharge of the air compressor 100 are discharged via the air discharge air intake pipe 22. Connect side piping. When the air compressor 100 is in driving operation (S101: No), the process proceeds to S108, and the three-way solenoid valve 60 is set to “closed” so that the air discharged from the air compressor 200 flows through the external air discharge pipe. .

In S105, the unit control unit instructs the control unit 26A to set the discharge solenoid valve 17 of the air compressor 100 to “close”, the operation solenoid valve 18 to “close”, and the regeneration solenoid valve 19 to “open”. . Thereafter, the air compressor 200 is discharged by an unload operation or an automatic stop operation, and the rotating electrical machine 6 of the air compressor 100 is reversed to generate power. The generated power is sent to the air compressor 200 via the converter 8.

In S107, the control unit 26B causes the electric power sent from the air compressor 100 to be sent to the fan motor inverter 16 and used as regenerative energy.

Thus, according to the second embodiment, electric power can be generated using the air discharged from another air compressor. In addition, in the case of regeneration with a single air compressor, power can be generated only with the air discharged during the automatic stop operation, but in the case of Example 2, the air discharged during the unload operation of the other air compressor is used. be able to.

In the second embodiment, the regenerative power is used as the power for the fan of the air compressor 200. However, it can be used for other purposes as well as the first embodiment.

As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to the said various Example, A combination and an omission are possible in the range which does not deviate from the meaning.
For example, in the second embodiment, the regenerative power generated by the air compressor 100 is used as the power for the fan of the air compressor 200, but the regenerative power is used as a (re) starting auxiliary power source for the air compressor 100. It is good also as the charge use.

Moreover, in Example 2, it is the structure which generate | occur | produces electricity only with the air compressor 100, However, The air compressor 200 is also provided with the same electric power generation mechanism, and each other ventilating piping system is connected to the other venting air intake piping. May be connected to each other, and the roles may be switched between the two depending on the driving situation. For example, from the aspect of ensuring the life of the equipment, in a control mode in which driving and stopping are alternately performed so that the driving time of a plurality of compressors is smoothed, the air discharged from both can be used for power generation.

Moreover, in Example 2, when using the excess compressed air of

external tank

45A, 45B and a user side apparatus for regeneration, it was made to take in via a ventilating air intake piping, but pressure regulation check valve 11 is changed. A bypass pipe and a valve body that permits and prohibits the circulation of the bypass pipe may be provided so that air discharged from an external tank or the like flows backward from the discharge side.

Further, in the second embodiment, the line power is obtained by the electric / electronic control by the number control unit 50 or the like. However, the air compressor main body 100 is not a spare system but a compressor system in which a plurality of units are driven and stopped in cooperation. It may be an air compressor, normally used only as a power generator, and may be used as an air compressor if necessary.

DESCRIPTION OF SYMBOLS 1 ... Suction filter, 2 ... Suction throttle valve, 3 ... Injection valve, 4 ... Element for injection, 5 ... Compressor body, 6 ... Rotary motor, 7 ... Inverter for rotary motor, 8 ... Power regeneration converter, 9 ... Oil separator, 10 ... element, 11 ... pressure regulating check valve, 12 ... temperature regulating valve, 13: heat exchanger (oil cooler / aftercooler), 14 ... cooling fan, 15 ... fan motor, 16 ... for fan motor Inverter, 17 ... Air release solenoid valve, 18 ... Operation solenoid valve, 19 ... Regenerative solenoid valve, 20 ... Oil filter, 21: Oil receiver and recovery path, 22 ... Air release air intake pipe, 23 ... External housing (package) ), 25 ... Temperature sensor, 26 / 26A / 26B ... Control unit, 27 ... Control panel, 28 ... Pressure sensor, 30 ... Lubricating oil path, 31 ... Control piping path, 41 ... Oil receiver, 42 ... Check valve, 45・ 45A ・ 45B… External Link (reservoir tank), 50 ... count control unit, 60 ... three-way solenoid valve 100-200 ... air compressor 300 ... air compressor system

Claims

A gas compressor having a compressor body that sucks gas and generates compressed gas,
A rotating electric machine that is a motor that receives supply power and drives the compressor body and that generates power from the compressor body and generates regenerative power;
An inverter that controls the rotational speed of the rotating electrical machine by changing the frequency of the supplied power;
A converter that generates output power from the generated power;
On the discharge side piping of the compressor body, it has a check valve that permits the flow of compressed air from the compressor body side to the discharge side,
A gas compressor that generates power for generating regenerative electric power when the compressor main body is reversely rotated by the backflow of compressor air upstream from the check valve when driving of the compressor main body is stopped.
The gas compressor according to claim 1,
A gas compressor in which the compressor body is a liquid supply type and has a gas-liquid separator downstream of the compressor body and upstream of the check valve.
The gas compressor according to claim 2,
A suction throttle valve that is installed on the intake path of the compressor body and permits and prohibits the flow of intake gas by opening and closing;
A suction throttle valve control device for controlling opening and closing of the suction throttle valve;
An ejection piping path that branches from the intake path downstream of the suction throttle valve and between the compressor bodies;
A valve body that permits and prohibits communication between the intake path and the ejection pipe path by opening and closing;
A valve body control device for controlling opening and closing of the valve body;
An oil element downstream of the ejection pipe path;
A gas compressor in which the suction throttle valve control device closes the suction throttle valve and the valve body control device opens the valve body when driving of the compressor body is stopped.
The gas compressor according to claim 3,
The gas compressor, wherein the suction throttle valve control device is an electromagnetic valve installed on a piping path connecting the gas-liquid separator and the suction throttle valve.
The gas compressor according to claim 3,
A gas compressor, wherein the valve body control device is an electromagnetic valve installed on a piping path connecting the gas-liquid separator and the valve body.
The gas compressor according to claim 3,
A gas compressor having an oil recovery mechanism for recovering the lubricating oil recovered by the oil element and returning it to the compressor body.
The gas compressor according to claim 1,
A pressure detection device for detecting a discharge side pressure downstream from the check valve;
Based on the detected pressure of the pressure detection device, having a control unit for controlling the inverter,
The gas compressor, wherein the control unit causes the inverter to stop driving the compressor body when the detected pressure reaches a predetermined pressure.
The gas compressor according to claim 7,
A gas compressor in which the control unit stops the compressor body after increasing the discharge side pressure to at least the predetermined pressure.
The gas compressor according to claim 8, wherein
A gas compressor in which the control unit re-drives the rotating electrical machine as an electric motor after a predetermined time has elapsed after the driving of the compressor main body is stopped or when the discharge side pressure detects a predetermined pressure.
The gas compressor according to claim 7,
An air discharge pipe for discharging compressed air upstream from the check valve, and an air discharge valve installed on the air discharge pipe,
When the detected value of the pressure detection device reaches a predetermined pressure, the control unit rotates the rotational speed of the rotating electrical machine at a rotational speed less than a rated value, and opens and closes the discharge valve to set a discharge side pressure within a predetermined pressure range. A gas compressor that performs an unloading operation that is maintained at a low level.
The gas compressor according to claim 10,
When the control unit detects the elapse of a predetermined time after the discharge valve is closed in the unload operation and before the detection value of the pressure detection device reaches the lower limit pressure of the predetermined pressure range, the inverter A gas compressor for stopping the drive of the compressor body.
The gas compressor according to claim 1,
Communicating with the discharge piping path from the discharge side of the compressor body to the upstream of the check valve, and an external intake piping for taking in compressed gas from the outside;
A valve body that permits and prohibits communication between the discharge pipe and the external intake pipe;
A gas compressor in which the control unit permits communication between the discharge pipe and an external intake pipe when driving of the compressor body is stopped.
A gas compressor according to claim 12,
Branching from the external intake pipe, and having an air discharge pipe communicating with the outside,
The valve body that permits and prohibits communication between the discharge pipe and the external intake pipe is either allowed only for communication between the discharge pipe and the external intake pipe, or is allowed only for communication between the external intake pipe and the exhaust pipe. Is a three-way valve that switches between
The gas compressor in which the control unit permits only the communication between the external intake pipe and the exhaust pipe for the three-way valve when the compression main body is driven.
A gas compressor according to claim 12,
A gas compressor in which the compressed gas taken in from the external intake pipe is supplied from another gas compressor.
A gas compressor according to claim 14,
The gas compressor whose compressed gas taken in from the said external taking-in piping is an air release gas by the unload operation or drive stop of another gas compressor.
13. The gas compressor according to claim 12, wherein the compressed gas taken in from the external intake pipe is an external tank that stores compressed air generated by the gas compressor.
A gas compressor system comprising a plurality of gas compressors having a compressor body that sucks gas and generates compressed gas,
At least one gas compressor A of the plurality of gas compressors is an electric motor that receives supply power and drives the compressor main body, and also serves as a generator that generates power from the compressor main body and generates regenerative power. Electric
An inverter that controls the rotational speed of the rotating electrical machine by changing the frequency of the supplied power;
A converter that generates output power from the generated power;
On the discharge side piping of the compressor body, a check valve that permits the flow of compressed air from the compressor body side to the discharge side;
Communicating with the discharge piping path from the discharge side of the compressor body to the upstream of the check valve, and having an external intake piping for taking in compressed air from one or more other gas compressors B,
During operation standby of the compressor body, the compressor body is reversely rotated by the compressor air taken in from the external intake pipe, and generates power to generate the regenerative power,
The gas compressor B is
An electric motor that drives the compressor body, and a check valve that permits the flow of compressed air from the compressor body side to the discharge side on the discharge side piping of the compressor body;
An exhaust pipe for releasing compressed air upstream from the check valve, and an air release valve installed on the exhaust pipe;
The gas compressor system comprises:
The external intake pipe of the gas compressor A communicates with the downstream from the air release valve of the gas compressor B,
A gas compressor having a control device that is communicably connected to the plurality of gas compressors, and that opens the gas release valve when the gas compression A is in operation standby and when the gas compressor B is discharged. system.