阅读说明：本技术 流体机械系统和流体机械 (Fluid machine system and fluid machine ) 是由 中岛崇 伊与泉彰 于 2019-07-25 设计创作，主要内容包括：本发明提供一种流体机械系统,其具有：对流体进行压送的流体机械；与所述流体机械连接的配管；与所述配管连接的终端负载；和检测所述配管的终端压力的终端压力传感器,其中,所述终端压力传感器与所述流体机械以可通信的方式连接,所述流体机械进行：基于所述终端压力的输入值进行运转的终端压力传感器控制运转；和在规定的设定压力加上基于所述配管的容量和该配管的压损值的差而得到的压力下的终端压力预测控制运转,来自所述终端压力传感器的输入中断或停止时,从终端压力传感器控制运转切换为终端压力预测控制运转。(The present invention provides a fluid machine system, comprising: a fluid machine for pressure-feeding a fluid; a pipe mechanically connected to the fluid; a terminal load connected to the pipe; and a terminal pressure sensor that detects a terminal pressure of the pipe, wherein the terminal pressure sensor is communicably connected to the fluid machine, and the fluid machine performs: a terminal pressure sensor control operation that operates based on the input value of the terminal pressure; and a terminal pressure prediction control operation under a pressure obtained by adding a difference between the capacity of the pipe and a pressure loss value of the pipe to a predetermined set pressure, wherein when the input from the terminal pressure sensor is interrupted or stopped, the terminal pressure sensor control operation is switched to the terminal pressure prediction control operation.)

1. A fluid mechanical system, having: a fluid machine for pressure-feeding a fluid; a pipe mechanically connected to the fluid; a terminal load connected to the pipe; and a terminal pressure sensor that detects a terminal pressure of the pipe, the fluid machine system being characterized in that:

the terminal pressure sensor is communicatively coupled to the fluid machine,

the fluid machine performs:

a terminal pressure sensor control operation that operates based on an input value from the terminal pressure; and

a terminal pressure prediction control operation under a pressure obtained by adding a difference between the capacity of the pipe and the pressure loss value of the pipe to a predetermined set pressure,

when the input from the terminal pressure sensor is interrupted or stopped, the terminal pressure sensor control operation is switched to the terminal pressure prediction control operation.

2. The fluid mechanical system of claim 1, wherein:

the fluid machine performs a pressure-increasing operation to a pressure higher than the terminal pressure and the predetermined set pressure before switching from the terminal pressure sensor control operation to the terminal pressure prediction control operation.

3. The fluid mechanical system of claim 1, wherein:

and a step of determining that the input from the terminal pressure sensor has been interrupted or stopped, when at least one of a case where the signal is not received from the terminal pressure sensor for a predetermined time and a case where the number of times the signal is not received in a predetermined time interval exceeds a predetermined number of times.

4. The fluid mechanical system of claim 1, wherein:

the fluid machine is a compressor or a pump.

5. A fluid mechanical system, having: a fluid machine for pressure-feeding a fluid; a pipe mechanically connected to the fluid; a terminal load connected to the pipe; and a terminal pressure sensor that detects a terminal pressure of the pipe, the fluid machine system being characterized in that:

the terminal pressure sensor is communicatively coupled to the fluid machine,

the fluid machine performs:

a terminal pressure sensor control operation that operates based on an input value from the terminal pressure; and

any one of P control, PI control and PID control according to a predetermined set pressure,

when the input from the terminal pressure sensor is interrupted or stopped, the terminal pressure sensor control operation is switched to any one of P control, PI control, and PID control.

6. The fluid mechanical system of claim 5, wherein:

the fluid machine performs a pressure raising operation to a pressure higher than the terminal pressure and the predetermined set pressure before switching from the terminal pressure sensor control operation to any one of P control, PI control, and PID control.

7. The fluid mechanical system of claim 5, wherein:

and a step of determining that the input from the terminal pressure sensor has been interrupted or stopped, when at least one of a case where the signal is not received from the terminal pressure sensor for a predetermined time and a case where the number of times the signal is not received in a predetermined time interval exceeds a predetermined number of times.

8. The fluid mechanical system of claim 5, wherein:

the fluid machine is a compressor or a pump.

9. A fluid machine, comprising: a fluid machine main body for pressure-feeding a fluid; and a control device that receives, by wire or wirelessly, a pressure value from a terminal pressure sensor that is disposed in a pipe through which a fluid that is pressure-fed to the outside of the fluid machine flows, the terminal pressure sensor detecting a terminal pressure of the pipe, the fluid machine being characterized in that:

the control device performs:

a terminal pressure sensor control operation that operates based on an input value from the terminal pressure; and

any one of the control operations is performed based on a predetermined set pressure preset in the control device or a known value stored in the control device and a calculated pressure obtained by a predetermined calculation,

when the input from the terminal pressure sensor is interrupted or stopped, the terminal pressure sensor control operation is switched to the one of the control operations.

10. The fluid machine according to claim 9, wherein:

the control operation based on a predetermined set pressure set in advance in the control device includes any one of operation control of P control, PI control, and PID control.

11. The fluid machine according to claim 9, wherein:

the operation based on the known value stored in the control device and the calculated pressure obtained by the predetermined calculation is a terminal pressure prediction control operation under a pressure obtained by adding a difference between the capacity of the pipe and the pressure loss value of the pipe to the predetermined pressure.

12. The fluid machine according to claim 9, wherein:

the control device performs a boosting operation up to a pressure higher than the terminal pressure, the predetermined set pressure, and the calculated pressure before switching from the terminal pressure sensor control operation to the one of the control operations.

13. The fluid machine according to claim 9, wherein:

and determining that the input from the terminal pressure sensor has been interrupted or stopped when at least one of a case where no signal has been received from the terminal pressure sensor for a predetermined time and a case where the number of times no signal has been received in a predetermined time interval exceeds a certain number of times.

14. The fluid machine according to claim 9, wherein:

the fluid machine is a compressor or a pump.

Technical Field

The present invention relates to a fluid machine system and a fluid machine, and more particularly to a fluid machine system and a fluid machine that perform operation control based on a pressure value in an external piping path.

Background

Various fluid machines such as compressors and pump devices are known as the fluid machine. For example, in the case of a compressor for compressing various gases such as air, the discharged compressed gas is stored in a storage tank and supplied from the storage tank to each terminal (load) via a utility pipe or the like. The pressure of the compressed gas is subjected to pressure loss due to the specification of the compressed gas at each terminal and expansion of the plant piping and the like.

As a technique for obtaining a desired pressure at each terminal in response to such pressure loss or the like, a technique for controlling the driving of a gas compressor based on the input of a pressure sensor value disposed in the middle of a facility pipe or the like is known, and a technique for controlling the driving by predicting the pressure at each terminal from the fluctuation of the discharge pressure without providing a pressure sensor in the middle of a facility pipe or the like is disclosed in patent documents 1 to 4.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 4425768

Patent document 2: japanese patent No. 4756081

Patent document 3: japanese patent No. 4786443

Patent document 4: japanese patent No. 5091787

Disclosure of Invention

Technical problem to be solved by the invention

Here, a configuration is considered in which the drive control of the fluid machine is performed based on an input from a terminal pressure sensor disposed in the middle of the facility pipe. The pressure sensor and the fluid machine can be connected in wired or wireless communication. In some cases, input of a terminal pressure value in a fluid machine is interrupted due to a communication failure such as disconnection if the fluid machine is wired or due to a wireless communication failure. In particular, in the case of wireless communication, the wireless communication system is likely to be affected by the environment (high temperature, high humidity, and the like) on the communication line, and is likely to be interrupted. The stop or interruption of communication has an influence on the driving of the fluid machine, and there is a fear that a desired terminal pressure cannot be secured.

Means for solving the problems

For such a problem, for example, the following structure is applied. Namely, a fluid machine system having: a fluid machine for pressure-feeding a fluid; a pipe mechanically connected to the fluid; a terminal load connected to the pipe; and a terminal pressure sensor that detects a terminal pressure of the pipe, in the fluid machine system, the terminal pressure sensor is communicably connected to the fluid machine, and the fluid machine performs: a terminal pressure sensor control operation that operates based on the input value of the terminal pressure; and a terminal pressure prediction control operation under a pressure obtained by adding a difference between the capacity of the pipe and a pressure loss value of the pipe to a predetermined set pressure, wherein when the input from the terminal pressure sensor is interrupted or stopped, the terminal pressure sensor control operation is switched to the terminal pressure prediction control operation.

In another aspect, a fluid machine system includes: a fluid machine for pressure-feeding a fluid; a pipe mechanically connected to the fluid; a terminal load connected to the pipe; and a terminal pressure sensor that detects a terminal pressure of the pipe, in the fluid machine system, the terminal pressure sensor is communicably connected to the fluid machine, and the fluid machine performs: a terminal pressure sensor control operation that operates based on the input value of the terminal pressure; and any one of operation control of P control, PI control, and PID control corresponding to a predetermined set pressure, wherein when the input from the terminal pressure sensor is interrupted or stopped, the operation is switched from the terminal pressure sensor control to any one of P control, PI control, and PID control.

Effects of the invention

According to the present invention, even if a communication failure occurs from the terminal pressure sensor, compressed gas at an appropriate terminal pressure can be supplied.

Other problems, structures, and effects of the present invention will be apparent from the following description.

Drawings

Fig. 1 is a schematic diagram showing the structure of an air compressor system to which embodiment 1 of the present invention is applied.

Fig. 2 is a schematic diagram showing the structure of the constant speed compressor of embodiment 1.

Fig. 3 is a schematic diagram showing the structure of the variable speed compressor of embodiment 1.

Fig. 4 is a flowchart of the terminal pressure sensor control and the terminal pressure prediction control in embodiment 1.

Fig. 5 is a flowchart of communication failure determination control in embodiment 1.

Fig. 6 is a flowchart of forced boosting control in embodiment 1.

Fig. 7 is a flowchart of the terminal pressure prediction control in embodiment 1.

Fig. 8 is a flowchart of a modified example of performing the terminal pressure sensor control and the terminal pressure prediction control.

Fig. 9 is a flowchart of the terminal pressure sensor control and the P/PI/PID control according to embodiment 2 to which the present invention is applied.

Detailed Description

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

Example 1

Fig. 1 schematically shows the structure of an air compressor system to which embodiment 1 of the present invention is applied. An air compressor system comprising: a compressor 3 having a compressor main body 1 and a pressure sensor P4 disposed on a discharge line; an air tank 4; an air filter 5; terminal piping branched to each terminal device (loads 7, 9, 11); and terminal pressure sensors 6, 8, 10 disposed in the respective terminal pipes.

The compressed air discharged (pressure-fed) from the compressor 3 is sent to an air tank 4 provided on the downstream side of the compressor 3, and the air tank 4 stores the compressed air. The compressed air stored in the air tank 4 is supplied to the loads 7, 9, and 11, which are the terminal devices requiring compressed air, through the air filter 5 provided on the downstream side of the air tank 4. The terminal pressure sensors 6, 8, and 10 disposed in the terminal pipes connected to the loads 7, 9, and 11 transmit the detected pressures to the compressor 3 at predetermined time intervals.

The structure of the compressor 3 is schematically shown in fig. 2. The compressor 3 includes a compressor main body 1, a control device 13, a suction throttle valve 14, a suction filter 15, a part of a discharge air system 16 including a check valve 17 and a pressure sensor 2, a pipe 19, and a control valve 20, and is provided as a so-called hermetic compressor in which these are housed in a casing.

The compressor body 1 receives a driving force from a driving source (for example, an electric motor, an internal combustion engine, or the like), sucks air from a suction side through a suction filter 15, and discharges compressed air to a discharge air system 16. A check valve 17 is disposed in the exhaust air system 16, and a pressure sensor 2 is disposed downstream thereof. The pressure sensor 2 transmits the detected pressure value to the control device 13, and the control device 13 performs various operation controls. A control valve 20, which is configured by an electromagnetic valve or the like, is disposed in a pipe 19 branched from the exhaust air system 16. The control valve 20 opens and closes the valve in response to a command from the control device 13, and allows and restricts the flow of compressed air through the pipe 19.

The suction throttle valve 14 is disposed downstream of the pipe 19. The intake throttle valve 14 is constituted by a piston that performs an opening and closing operation of an intake path by a control pressure generated by compressed air. For example, when the consumption amount of compressed air is reduced, the no-load operation is performed in which the intake throttle valve 14 is closed to restrict the inflow of atmospheric air into the compressor main body 1, thereby reducing the power consumption.

The control device 13 is configured to realize a control function unit (a part or all of which may be a control structure configured by an analog circuit) by cooperation of a CPU and a program, for example. The control device performs operation control based on a predetermined set pressure. In the present embodiment, the set pressure is a value set by a user operation or an external input designation, for example. The control device 13 monitors the pressure values from the terminal pressure sensors 6, 8, and 10, and controls the operation based on the pressure values. That is, by setting a terminal pressure value required on the terminal side as a set pressure, the control device 13 monitors the pressure values from the terminal pressure sensors 6, 8, and 10 and the set pressure (required terminal pressure), and can supply compressed air at the required terminal pressure.

The compressor 3 is configured as a constant speed machine, but the present invention can also be applied to a transmission. Fig. 3 schematically shows the structure of the compressor 33 in the case of a transmission. The compressor 33 includes: a compressor main body 22; a motor 23 for driving the compressor main body 22; an inverter 24 for controlling the rotational speed of the motor 23 in a variable speed manner; a control device 25 for controlling the inverter 24; a suction throttle valve 26 provided on the suction side of the compressor main body 22; an intake filter 27 disposed upstream of the intake throttle valve 26 for removing dust and the like in the atmosphere; and a discharge air system 28 connected to the discharge side of the compressor main body 22 and supplying compressed air discharged from the compressor main body 22 to a supply target.

A check valve 29 is disposed in the discharge air system 28, and a pressure sensor 30 is disposed downstream of the check valve 29 as a device for detecting the discharge pressure of the compressor main body 22. Further, a pipe 31 for introducing a part of the compressed air discharged from the compressor main body 22 as air for operation of the intake throttle valve 26 is connected to the upstream side of the check valve 29 of the discharge air system 28, and a control valve 32 which can be switched to an on/off state in response to a control signal from the control device 25 is provided in the pipe 31. For example, when the control valve 32 is switched from the cut-off state to the connected state, the suction throttle valve 26 is driven to cut off the suction of the compressor main body 22, and the compressor main body 22 is switched from the load operation to the no-load operation.

The configuration of the control device 25 for monitoring the values of the terminal pressure sensor 6 and the like and controlling the operation is the same as that of the compressor 3 shown in fig. 2.

Next, a description will be given of a control in which the control device 13 automatically switches to the terminal pressure predicting operation when the input from the terminal pressure sensors 6, 8, and 10 is interrupted or stopped, which is one of the features of the present embodiment.

For example, if a phenomenon occurs in which the compressor system is installed in a factory building, such as a power failure or a failure of the terminal pressure sensor in a communication path between all or a part of the terminal pressure sensors 6, 8, and 10 and the compressor 3, or a disconnection of a communication line in a wired state, which causes communication to be blocked, the compressor 3 cannot know an actual measured value of the terminal pressure. In the case of wireless communication, the cause of communication inhibition may be, for example, transmission of a large vehicle such as a truck or a shield such as a reinforcing bar across a communication line, or radiation of a large amount of heat from a high-temperature body such as an electric furnace.

In such a case, the control device 13 and the like switch from the operation based on the measured pressure of the terminal pressure sensor 6 and the like to the control of the terminal pressure prediction operation disclosed in patent document 1 and the like. This makes it possible to continuously supply compressed air having an appropriate final pressure.

In addition, the cause of the obstructed communication may be temporary. Then, in the present embodiment, the terminal pressure prediction control is switched to after a predetermined time has elapsed since the communication from the terminal pressure sensor 6 or the like was interrupted. Alternatively, the control may be switched based on the number of communication interruptions in a predetermined time or the cumulative interruption time.

The flow of control performed by the compressor 3 and the like in the above configuration will be described.

Fig. 4 shows a flowchart of the terminal pressure prediction control performed after the pressure is increased to the upper limit pressure when the communication between the compressor 3 and the terminal pressure sensor 6 is interrupted or interrupted. The following processing is performed by the control devices 13 and 25.

In the process 34, the terminal pressure sensor value is controlled to a target value with respect to the discharge pressure of the compressor unit during operation.

In the process 35, the control device 13 or the like manages whether or not there is an input from the terminal pressure sensor 6 or the like under a predetermined condition. Then, in the process 36, if there is an input satisfying the condition, the process returns to the process 34 (NO), and if there is NO input satisfying the condition, the process proceeds to a process 37 (YES) in view of the occurrence of a communication failure. The "communication determination process" will be described later.

In the processing 37, "forced pressure increase control" is executed in which the load operation is performed until the pressure is increased until the pressure sensor value of the compressor unit becomes the upper limit pressure so that the air pressure at the end is not decreased. The upper limit pressure is a pressure higher than the pressure value in the terminal pressure sensor control, and is, for example, a pressure lower than the safety pressure of the compressor 3 or the like and higher than the detection pressure of the terminal pressure sensor 6 or the like.

In the process 38, the maximum pressure loss, the total pipe capacity, and the current predicted pressure loss required for the terminal pressure prediction control are calculated.

In the process 39, the terminal pressure prediction control is performed based on the calculation result of the process 38.

In the processes 40 and 41, it is checked whether or not the value of the terminal pressure sensor is normally acquired, in the same manner as in the processes 35 and 36, and when the value is normally acquired, the process proceeds to the process 34, and the terminal pressure sensor control is restarted. If the normal acquisition is not performed, the process proceeds to step 38, and the terminal pressure prediction control is continued.

Next, fig. 5 is a flowchart showing a flow of "communication determination processing" in the processing 35 of fig. 4.

In the processes 55 to 59, when the value of the terminal pressure sensor cannot be received for a certain time or longer, the value of the terminal pressure sensor cannot be intermittently received, or the obtained value of the terminal pressure sensor is abnormal, it is regarded that a communication failure has occurred, and when the value of the terminal pressure sensor is received within a certain time, the value of the terminal pressure sensor is not intermittently received, and the obtained value of the terminal pressure sensor is not abnormal, it is regarded that the value of the terminal pressure sensor has been normally obtained, and the terminal pressure sensor communication determination process is ended.

In this way, in consideration of conditions such as the input time and the number of times of non-reception, when the factor that inhibits communication occurring on the communication line is a very short time and temporary, it is preferable to continue the terminal pressure sensor control in terms of maintenance of the equipment and continuity of operation of the system.

Fig. 6 shows a flowchart of "forced boosting control" in which the processing 37 of fig. 4 is performed.

In process 60, the discharge pressure of the compressor unit is compared with the upper limit pressure, and the forced pressure-increasing control is ended when the discharge pressure of the unit exceeds the upper limit pressure. The discharge pressure of the unit is transferred to process 61 below the upper pressure limit. In steps 61 and 62, when the compressor unit is in a stopped or no-load state, the operation is forcibly switched to the load operation, and the process proceeds to step 60. When the load operation is already performed, the load operation is continued, and the process proceeds to step 60.

This is because the terminal pressure is unknown due to a communication failure, and therefore, the terminal pressure required is not reduced from the predetermined pressure by forcibly raising the terminal pressure to the upper limit pressure. For example, when a communication failure occurs, the amount of air used in each load 7 or the like may increase compared to before. In this case, the required terminal-side pressure can be sufficiently ensured. Further, it is considered that the present invention also contributes to securing the calculation time and the like of the control devices 13 and 25 and the like required for the terminal pressure prediction control described below.

Fig. 7 shows a flowchart for performing the "terminal pressure prediction control" of fig. 4.

In the processes 63 and 64, if the calculation of the maximum pressure loss required for the terminal pressure prediction control is completed, the process proceeds to a process 65, and if the calculation of the maximum pressure loss required for the terminal pressure prediction control is not completed, the maximum pressure loss required for the terminal pressure prediction control is calculated from the trend data, and the process proceeds to a process 65. In the processes 65 to 67, if the calculation of the total pipe capacity required for the terminal pressure prediction control of the constant speed machine or the constant speed machine is not completed, the routine proceeds to a process 68, and if the calculation of the total pipe capacity required for the terminal pressure prediction control of the constant speed machine is not completed in the case of the constant speed machine, the routine calculates the total pipe capacity required for the terminal pressure prediction control of the constant speed machine from the trend data, and proceeds to a process 68. In the process 68, the pressure loss required for the terminal pressure prediction control is calculated, and the calculation for the terminal pressure prediction control is ended.

[ modified examples ]

In the above-described processing shown in fig. 4, an example of starting the "terminal pressure prediction control" after the input from the terminal pressure sensor 6 or the like is interrupted/stopped (communication failure occurs) has been described, but control switching may not be performed immediately because it requires activation of various programs or the like.

As a modification, a configuration may be adopted in which the "terminal pressure prediction control" and the "terminal pressure sensor control" are executed in parallel, and the "terminal pressure prediction control" can be immediately executed upon occurrence of a communication failure (a "background operation of the terminal pressure prediction operation").

Fig. 8 shows a flowchart of a modification in which the calculation necessary for the terminal pressure prediction control is performed simultaneously with the terminal pressure sensor control, and the terminal pressure prediction control is performed when the communication between the compressor unit and the terminal pressure sensor is not possible.

In process 50, the terminal pressure sensor value is controlled to the target for the discharge pressure of the compressor unit during operation. In the processing 51, the maximum pressure loss, the total pipe capacity, and the current predicted pressure loss required for the terminal pressure prediction control are calculated. In the processes 52 to 54, it is checked whether or not the value of the terminal pressure sensor is normally acquired, and if the value is normally acquired, the process proceeds to the process 50, and the terminal pressure sensor control is continued. If the normal acquisition is not performed, it is determined that there is a communication failure, and the process proceeds to the process 54 to perform the terminal pressure prediction control. Then, the process proceeds to a process 51, a calculation necessary for the terminal pressure prediction control is performed to check whether or not the value of the terminal pressure sensor is normally acquired, and if the value is normally acquired, the process proceeds to a process 50, and the terminal pressure sensor control is restarted. If the normal acquisition is not performed, the process proceeds to step 54, and the terminal pressure prediction control is continued.

As described above, according to embodiment 1 and the modification, even if a communication failure occurs in the terminal pressure sensor 6 or the like, the continuous operation in which the decrease in the terminal pressure is suppressed can be performed.

In the above example, in the determination of the communication failure, stable control that does not respond immediately to the occurrence of an instantaneous or temporary communication failure factor can be performed by using the reception interval from the terminal pressure sensor 6 or the like, the number of times of non-reception in a predetermined time interval, or the like as a condition for the occurrence of the failure.

In the above example, since the forced boosting operation is performed up to the upper limit pressure when the communication failure occurs, a constant pressure guarantee can be performed for the terminal pressure from the occurrence of the failure to the control switching and the operation recovery thereof.

In the above example, during execution of the "terminal pressure prediction control" after occurrence of the communication failure, the communication state of the terminal pressure sensor 6 and the like is continuously checked, and when the communication state is restored, the communication state is switched to the "terminal pressure sensor control", so that the reliability of the compressor system having the backup control based on the operation control based on the measured pressure is improved.

Example 2

In embodiment 1 and the like, the configuration is switched to the "terminal pressure prediction operation control" when communication with the terminal pressure sensor 6 and the like is failed, and embodiment 2 is a configuration example in which the switching is changed to the "P/PI/PID control".

Fig. 9 shows a flowchart of P/PI/PID control performed with a specific pressure value as a target when communication between the compressor 33 and the terminal pressure sensor 6 or the like is not possible in embodiment 2. In the present embodiment, any of P control, PI control, and PID control can be applied.

In process 46, the terminal pressure sensor value is controlled to the target for the discharge pressure of the compressor unit during operation. In steps 47 to 49, it is checked whether or not the value of the terminal pressure sensor is normally acquired, and if the value is normally acquired, the process proceeds to step 46, and the terminal pressure sensor control is continued. If the communication failure is not normally acquired, it is determined that there is a communication failure, and the process proceeds to process 49, where P/PI/PID control is performed so that the pressure sensor value of the compressor unit becomes one of a fixed value input in advance, a target terminal pressure value immediately before the communication failure (before the communication failure), or a value obtained by adding a correction value to the target terminal pressure immediately before the communication failure.

Then, the process proceeds to processes 47 to 49, and it is checked whether or not the value of the terminal pressure sensor is normally acquired, and if the value is normally acquired, the process proceeds to process 46, and the value of the terminal pressure sensor is controlled to the target. If the normal acquisition is not performed, it is determined that there is a communication failure, and the process proceeds to process 49 to continue the P/PI/PID control.

According to embodiment 2, the compressor system can be continuously operated based on a specific set pressure in response to a communication failure of the terminal pressure sensor 6 or the like.

In addition, the process 37 of embodiment 1, the "forced boosting operation" may be executed when the "terminal pressure sensor control" is switched to the "P/PI/PID control". In addition, similarly to the modification of embodiment 1, the "P/PI/PID control" may be operated as the background control of the "terminal pressure sensor control", and the control may be switched immediately when a communication failure occurs.

The embodiments for carrying out the present invention have been described above, but the present invention is not limited to the above-described various embodiments, and various changes and substitutions can be made without departing from the spirit and scope of the present invention. For example, the terminal pressure sensor 6 and the like are not limited to being disposed upstream near each load, and may be based on an intermediate terminal pressure such as upstream of the branch pipe.

The control may be performed when all of the plurality of terminal pressure sensors disposed in the pipe have a communication failure, or may be performed when some of the plurality of terminal pressure sensors have a communication failure.

In addition, although the above example has exemplified a compressor, the present invention can also be applied to a pump device or the like that pumps a fluid. As for the form of the compressor, various compressors such as a turbine type and a displacement type can be applied. The compressor may be a compressor that compresses other gas without being limited to air.

Description of the reference numerals

1. 22 … …, an air tank … … 4, an air filter … … 5,

6. 8, 10 … … terminal pressure sensors, 7, 9, 11 … … loads, 13 … … control devices, 14, 26 … … suction throttle valves, 15, 27 … … suction filters, 16, 28 … … exhaust air systems, 17, 29 … … check valves, 18, 30 … … pressure sensors, 19 … … piping, 20 … … control valves, 23 … … motors, 24 … … inverters, 31 … … piping, 32 … … control valves, 33 … … compressors.