Compression system

Abstract

This compression system provides a mechanism that can continue supplying compressed gas to customers even if the control system for controlling the number of units malfunctions. [Solution] The system comprises a communication line and a plurality of compressors interconnected by the communication line and supplying compressed gas to a customer at a predetermined supply pressure. The plurality of compressors consist of a control entity and a control object, and under normal circumstances, they share operational information via the communication line, so that if the control entity malfunctions, the control object continues to supply the compressed gas.

Description

Technical Field

[0001] The present invention relates to a compression system.

Background Art

[0002] Patent Document 1 below discloses a group control air compression system capable of group controlling a plurality of air compressors without providing a dedicated group control device. This group control air compression system interconnects a plurality of air compressors communicably using a communication line, and each air compressor is provided with a switching function to a master unit mode or a slave unit mode, so that any one of the plurality of air compressors functions as a master unit and the rest function as slave units.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a compression system including a plurality of compressors, it is desired to perform number control to switch the number of compressors (operating number) to be operated according to the required amount of compressed gas. However, in the conventional number control, when an abnormality occurs in the master unit which is the control main body of the number control, the slave units which are the control objects cut off the supply of compressed gas to the demand destination. That is, the conventional number control has a problem that when an abnormality occurs in the master unit, the supply of compressed gas to the demand destination stops.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a compression system capable of continuing the supply of compressed gas to the demand destination even when the control main body of the number control becomes abnormal.

Means for Solving the Problems

[0006] To achieve the above objective, the present invention provides a first solution relating to a compression system, comprising a communication line and a plurality of compressors interconnected by the communication line and supplying compressed gas to a customer at a predetermined supply pressure. The plurality of compressors consist of a control entity and a control object for number control, and under normal circumstances, they share operational information via the communication line, so that if the control entity becomes abnormal, the control object continues to supply the compressed gas.

[0007] In the present invention, as a second solution relating to the compression system, in the first solution described above, the control object, upon detecting an abnormality in the control entity via the communication line, cancels the unit control and continues supplying the compressed gas by performing autonomous operation.

[0008] In the present invention, as a third solution relating to the compression system, in the first solution described above, the control object, upon detecting an abnormality in the control entity via the communication line, continues to supply the compressed gas by performing a simulated multi-unit control operation using individually set target pressures.

[0009] In the present invention, as a fourth solution relating to the compression system, in the second or third solution described above, a plurality of compressors are equipped with individual pressure sensors for detecting the pressure of the compressed gas, and if an abnormality occurs in one of its own individual pressure sensors, it acquires the detected values ​​of other individual pressure sensors via the communication line to perform autonomous operation or operation by the number of units controlled.

[0010] In the present invention, as a fifth solution relating to the compression system, a means is adopted in which, in any of the first to fourth solutions described above, the multiple compressors share specification information via the communication line.

[0011] In the present invention, as a sixth solution relating to the compression system, the present invention adopts a means in which, in any of the first to fifth solutions described above, a collection tank T is provided which is connected to a plurality of compressors via a collection pipe H, the collection tank T is equipped with one or more main pressure sensors for detecting the supply pressure, and the plurality of compressors are equipped with one or more individual pressure sensors for detecting the pressure of the compressed gas sent to the collection pipe.

[0012] In the present invention, as a seventh solution relating to the compression system, the main pressure sensor is configured to transmit the supply pressure to a plurality of compressors via the communication line, in accordance with the sixth solution described above.

[0013] In the present invention, as an eighth solution relating to the compression system, a means is adopted in which any of the first to seventh solutions described above is equipped with a data acquisition device that performs mote monitoring by acquiring the operation information via the communication line. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a compression system that can continue supplying compressed gas to customers even if the control unit for the number of units malfunctions. [Brief explanation of the drawing]

[0015] [Figure 1] This is a block diagram showing the configuration of a compression system related to a batch of blocks. [Figure 2] This is a schematic diagram illustrating serial communication between multiple control units in one embodiment of the present invention. [Figure 3] This is a schematic diagram showing the control information of multiple control units in one embodiment of the present invention. [Figure 4] This is a flowchart showing the operation of a compressor according to one embodiment of the present invention. [Figure 5] This is a schematic diagram showing the abnormal control pressure in one embodiment of the present invention. [Figure 6]It is a flowchart showing the switching operation of an individual sensor in one embodiment of the present invention. [Figure 7] It is a schematic diagram showing the switching operation of an individual sensor in one embodiment of the present invention. [Figure 8] It is a first block diagram showing the configuration of a compression system according to a modified example of one embodiment of the present invention. [Figure 9] It is a second block diagram showing the configuration of a compression system according to a modified example of one embodiment of the present invention.

Mode for Carrying Out the Invention

[0016] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the compression system A according to the present embodiment includes a plurality (n units) of compressors C1 to Cn, a plurality (n - 1 pieces) of communication lines L1 to Ln - 1, a manifold pipe H, and a manifold tank T. The plurality (n units) of compressors C1 to Cn are machines that compress gas such as air to generate compressed gas, and each includes a main body part, a control part, and a pressure sensor.

[0017] Here, "n" in the present embodiment is a value indicating the equipment numbers of the n compressors C1 to Cn, and is a natural number of 5 or more. Compressor C1 is the first unit with the equipment number "1". Compressor C2 is the second unit with the equipment number "2". Compressor C3 is the third unit with the equipment number "3". Compressor C4 is the fourth unit with the equipment number "4". (Omitted) Compressor Cn is the nth unit with the equipment number "n".

[0018] That is, the first compressor C1 includes a main body part 1a, a control part 1b, and a pressure sensor 1c, the second compressor C2 includes a main body part 2a, a control part 2b, and a pressure sensor 2c, and the third compressor C3 includes a main body part 3a, a control part 3b, and a pressure sensor 3c. Also, the fourth compressor C4 includes a main body part 4a, a control part 4b, and a pressure sensor 4c, (omitted), and the nth compressor Cn includes a main body part na, a control part nb, and a pressure sensor nc.

[0019] Multiple (n) main body sections 1a, 2a, 3a, 4a, ..., na are functional sections that compress gases such as air taken in from the outside, and each generates compressed gas and sends it to the manifold piping H. That is, the first main body section 1a generates compressed gas and sends it to the manifold piping H, the second main body section 2a generates compressed gas and sends it to the manifold piping H, and the third main body section 3a generates compressed gas and sends it to the manifold piping H. Furthermore, the fourth main body section 4a generates compressed gas and sends it to the manifold piping H, (omitted), and the nth main body section na generates compressed gas and sends it to the manifold piping H.

[0020] Multiple (n) control units 1b, 2b, 3b, 4b, ..., nb are functional units that control the main units 1a, 2a, 3a, 4a, ..., na mentioned above, and control each main unit 1a, 2a, 3a, 4a, ..., na based on the equipment data (equipment information) of each unit.

[0021] In other words, the first control unit 1b is a functional unit that controls the first main unit 1a, and controls the first main unit 1a based on its own equipment data (Unit 1 data). The second control unit 2b is a functional unit that controls the second main unit 2a, and controls the second main unit 2a based on its own equipment data (Unit 2 data).

[0022] Furthermore, the third control unit 3b is a functional unit that controls the third main unit 3a, and controls the third main unit 3a based on its own equipment data (unit 3 data) as well as equipment data of units 1, 2, 4 to n (unit 1, 2, 4 to n data) acquired via communication lines L1 to Ln-1. The fourth control unit 4b is a functional unit that controls the fourth main unit 4a, and controls the fourth main unit 4a based on its own equipment data (unit 4 data) as well as equipment data of units 1 to 3, 5 to n (unit 1 to 3, 5 to n data) acquired via communication lines L1 to Ln-1. (omitted)

[0023] Furthermore, the nth control unit nb is a functional unit that controls the nth main unit na, and controls the nth main unit na based on its own equipment data (unit n data) as well as equipment data from units 1 to n-1 (unit 1 to n-1 data) acquired via communication lines L1 to Ln-1.

[0024] These n control units 1b, 2b, 3b, 4b, ..., nb are, for example, microcontrollers with external communication capabilities. That is, the n control units 1b, 2b, 3b, 4b, ..., nb each include at least a CPU, a memory, and a communication unit. The memory in the n control units 1b, 2b, 3b, 4b, ..., nb is provided with a shared memory for storing the equipment data of each unit.

[0025] These control units 1b, 2b, 3b, 4b, ..., nb each perform wired communication using communication lines L1 to Ln-1 by executing control programs pre-stored in memory, and control their respective main units 1a, 2a, 3a, 4a, ..., na based on the equipment data of each unit obtained through this wired communication.

[0026] More specifically, the n control units 1b, 2b, 3b, 4b, ..., nb acquire at least the following as equipment data for each unit: operation data (operation information) indicating the operating status of compressors other than the compressor corresponding to itself, and specification data (specification information) indicating the specifications of compressors other than the compressor corresponding to itself. The n control units 1b, 2b, 3b, 4b, ..., nb use this operation data (operation information) and specification data (specification information) to perform unit control in addition to normal control of each main unit 1a, 2a, 3a, 4a, ..., na.

[0027] In other words, the n control units 1b, 2b, 3b, 4b, ..., nb primarily perform the normal control of their respective main units 1a, 2a, 3a, 4a, ..., n, which is the function of generating compressed gas. In addition to this normal control, they also perform a secondary function of adjusting the number of operating units of the n compressors C1 to Cn. The aforementioned operation data (operation information) and specification data (specification information) are control information that is used not only for normal control but also for the number control of the n control units 1b, 2b, 3b, 4b, ..., nb.

[0028] Multiple (n) pressure sensors 1c, 2c, 3c, 4c, ..., nc are individual pressure sensors that detect the pressure of the compressed gas sent from each main unit 1a, 2a, 3a, 4a, ..., na to the collective piping H as the individual pressure of each compressor C1 to Cn. Each pressure sensor 1c, 2c, 3c, 4c, ..., nc (individual pressure sensor) outputs its individual pressure detection value (individual detection value) to its respective control unit 1b, 2b, 3b, 4b, ..., nb.

[0029] Specifically, the first pressure sensor 1c outputs a first individual detection value related to the first main body 1a to the first control unit 1b. The second pressure sensor 2c outputs a second individual detection value related to the second main body 2a to the second control unit 2b. The third pressure sensor 3c outputs a third individual detection value related to the third main body 3a to the third control unit 3b.

[0030] Furthermore, the fourth pressure sensor 4c outputs a fourth individual detection value relating to the fourth main body 4a to the fourth control unit 4b. (omitted) The nth pressure sensor nc outputs a nth individual detection value relating to the nth main body na to the nth control unit nb.

[0031] Multiple (n-1) communication lines L1 to Ln-1 are wires that allow communication between the control units of two compressors corresponding to adjacent equipment numbers. The n-1 communication lines L1 to Ln-1 are, for example, serial communication lines compliant with RS-485.

[0032] In other words, the first communication line L1 connects the first compressor C1, which is unit 1 (equipment number 1), and the second compressor C2, which is unit 2 (equipment number 2), in a manner that allows for communication. The second communication line L2 connects the second compressor C2, which is unit 2 (equipment number 2), and the third compressor C3, which is unit 3 (equipment number 3), in a manner that allows for communication.

[0033] The third communication line L3 connects the third compressor C3, which is unit 3 (equipment number 3), and the fourth compressor C4, which is unit 4 (equipment number 4), in a manner that allows for communication. The fourth communication line L4 connects the fourth compressor C4, which is unit 4 (equipment number 4), and the fifth compressor C5 (not shown), which is unit 5 (equipment number 5). (omitted) The Ln-1 communication line Ln-1 connects the n-1 compressor Cn-1 (not shown), which is unit n-1 (equipment number n-1), in a manner that allows for communication.

[0034] These n-1 communication lines L1 to Ln-1 each connect the control units of two compressors corresponding to adjacent equipment numbers using a multidrop method. In other words, the n-1 communication lines L1 to Ln-1 are communication lines that interconnect the n control units 1b, 2b, 3b, 4b, ..., nb as a whole, allowing for flexible communication.

[0035] The n control units 1b, 2b, 3b, 4b, ..., nb perform serial communication using n-1 communication lines L1 to Ln-1. However, the serial communication performed by the n control units 1b, 2b, 3b, 4b, ..., nb is not limited to wired communication using n-1 communication lines L1 to Ln-1. In other words, the serial communication in the n control units 1b, 2b, 3b, 4b, ..., nb may be wireless communication using radio waves or the like.

[0036] Here, we will describe serial communication performed by n control units 1b, 2b, 3b, 4b, ..., nb using n-1 communication lines L1 to Ln-1. This serial communication conforms to RS-485 at the physical layer of the OSI reference model, but employs TDMA (Time Division Multiple Access) and the token bucket method as communication methods for the layers above the physical layer.

[0037] In other words, each control unit 1b, 2b, 3b, 4b, ..., nb shares the respective communication lines L1 to Ln-1 by dividing the communication time into time slots (unit time). Furthermore, each control unit 1b, 2b, 3b, 4b, ..., nb pre-limits the amount of data that can be transmitted in a single time slot (unit time).

[0038] n control units 1b, 2b, 3b, 4b, ..., nb broadcast their own equipment data to other units at time slots set at regular time intervals. That is, the first control unit 1b broadcasts the equipment data (unit 1 data) of the first compressor C1 (unit 1) to the other control units 2b, 3b, 4b, ..., nb. The second control unit 2b broadcasts the equipment data (unit 2 data) of the second compressor C2 (unit 2) to the other control units 1b, 3b, 4b, ..., nb.

[0039] Furthermore, the third control unit 3b broadcasts the equipment data (unit 3 data) of the third compressor C3 (unit 3) to the other control units 1b, 2b, 4b, ..., nb. The fourth control unit 4b broadcasts the equipment data (unit 4 data) of the fourth compressor C4 (unit 4) to the other control units 1b, 2b, 3b, ..., nb. (omitted) The nth control unit nb broadcasts the equipment data (unit n data) of the nth compressor Cn (unit n) to the other control units 1b, 2b, 3b, 4b, ..., n-1b.

[0040] Although not shown in Figure 1, the compression system A according to this embodiment includes a control device that provides control commands to n control units 1b, 2b, 3b, 4b, ..., nb. This control device is connected to the first control unit 1b in the first compressor C1 (unit 1) by control lines (management control lines) similar to the n-1 communication lines L1 to Ln-1 described above.

[0041] This management device is the management station for wired communication (serial communication) in compression system A, and broadcasts management station data (management information) such as control commands and setting data (setting information) for n control units 1b, 2b, 3b, 4b, ..., nb to n control units 1b, 2b, 3b, 4b, ..., nb via the management control line and n-1 communication lines L1 to Ln-1.

[0042] Figure 2 is a schematic diagram of serial communication between n control units 1b, 2b, 3b, 4b, ..., nb and a management device (management station). As shown in Figure 2, the n control units 1b, 2b, 3b, 4b, ..., nb and the management device (management station) broadcast their own device data (device information), management station data (management information), and configuration data (configuration information) for each time slot (time slot 0, 1, 2, 3, ...) set at intervals of, for example, 100ms.

[0043] Through the broadcast transmission of data for units 1 through n of the n compressors C1 through Cn (units 1 through n) and the control unit (control station), as well as control station data and configuration data, each of the control units 1b, 2b, 3b, 4b, ..., nb stores its own equipment data, as well as data for other equipment, control station data, and configuration data, in addition to the equipment data itself, as shown in Figure 4.

[0044] In other words, n control units 1b, 2b, 3b, 4b, ..., nb, that is, n compressors C1 to Cn (units 1 to n), normally share equipment data (equipment information) between the n compressors C1 to Cn (units 1 to n) through serial communication via n-1 communication lines L1 to Ln-1.

[0045] The manifold piping H is a pipe that connects the discharge ports of the n main units 1a, 2a, 3a, 4a, ..., na to the inlet of the manifold tank T. In other words, the compressed gas discharged from the discharge ports of the n main units 1a, 2a, 3a, 4a, ..., na flows into the manifold tank T via the manifold piping H.

[0046] The collective tank T has an inlet connected to the collective piping H and an outlet connected to the compressed gas demand site. This collective tank T has a predetermined internal volume and temporarily stores the compressed gas from n compressors C1 to Cn that flow in via the collective piping H. This collective tank T also supplies the compressed gas flowing in from the n compressors C1 to Cn to the demand site according to the required flow rate.

[0047] Furthermore, the manifold tank T is equipped with a main pressure sensor P. The main pressure sensor P is a detector that detects the pressure of the compressed gas (main pressure) in the manifold tank T. This main pressure sensor P outputs the detected value of the main pressure (main detected value) to the first control unit 1b in the first compressor C1 (unit 1).

[0048] Here, the first compressor C1 (unit 1) is the compressor that initially functions as the master unit in the control of the number of n compressors C1 to Cn. The n-1 compressors C2 to Cn (units 2 to n), other than the first compressor C1 (unit 1), initially function as slave units in the control of the number of n compressors C1 to Cn.

[0049] The master unit is the control entity for the number of units, and the slave units are the control objects for the number of units. In other words, in the initial stages of operation, the compression system A according to this embodiment has the first compressor C1 (unit 1) functioning as the master unit (control entity) and instructing the n-1 compressors C2~Cn (units 2~n) that function as slave units (control objects) to start or stop. The n-1 compressors C2~Cn (units 2~n) start or stop based on the number of units control commands received from the first compressor C1 (unit 1) via n-1 communication lines L1~Ln-1.

[0050] Next, the characteristic operation of the compression system A according to this embodiment, that is, the method for controlling the number of n compressors C1 to Cn, will be explained with reference to Figures 4 to 8.

[0051] First, in this compression system A, the equipment data (1-n unit data) of each compressor C1-Cn (units 1-n) is stored in their respective shared memory (1-n unit shared memory) via broadcast transmission by n control units 1b, 2b, 3b, 4b, ..., nb. Then, the 1-n unit data in the 1-n unit shared memory is updated each time new equipment data is received.

[0052] In this compression system A, the first compressor C1 (unit 1) functions as the master unit (control entity), thereby controlling the number of second to n compressors C2 to Cn (units 2 to n), which are the slave units (control objects). In other words, the first compressor C1 (unit 1) controls the number of second to n compressors C2 to Cn (units 2 to n) based on the main detection value input from the main pressure sensor P.

[0053] The primary detection value of the main pressure sensor P is the pressure of the compressed gas in the collection tank T (main pressure), and it fluctuates according to the amount of compressed gas demanded at the customer. In other words, the primary detection value of the main pressure sensor P decreases as the demand increases. The first compressor C1 (unit 1) controls the number of compressors C2 to Cn (units 2 to n) to start / stop in accordance with the primary detection value of the main pressure sensor P.

[0054] Here, the first compressor C1 (unit 1) can recognize the operating status of each compressor C1 to Cn (units 1 to n) based on the operation data (operation information) included in the previously acquired data for units 1 to n. In addition, the first compressor C1 (unit 1) can recognize the basic performance of each compressor C1 to Cn (units 1 to n) based on the specification data (specification information) also included in the data for units 1 to n.

[0055] The first compressor C1 (unit 1), in controlling the number of compressors C2 to Cn (units 2 to n), appropriately selects which compressors to operate and which to stop operating by referring to the equipment data (unit 1 to n data) of each compressor C1 to Cn (units 1 to n) which are updated sequentially over time.

[0056] n-1 compressors C2-Cn (units 2-n), which function as slave units (control objects), determine whether the first compressor C1 (unit 1), which functions as the master unit, is abnormal or not based on the reception status of the equipment data or the content of the equipment data (step S1). If the determination in step S1 is "No", that is, if the first compressor C1 (unit 1) is normal, the n-1 compressors C2-Cn (units 2-n) perform normal serial communication processing, i.e., broadcast communication of equipment data, and control their own operation according to the master unit's commands (step S2).

[0057] On the other hand, if the judgment in step S1 is "Yes," that is, if the first compressor C1 (unit 1) is abnormal, the n-1 compressors C2-Cn (units 2-n) will cancel the unit control operation and switch to individual operation (step S3). In other words, the n-1 compressors C2-Cn (units 2-n) will switch their operating mode from unit control mode to independent operation mode and will continue to operate in a manner that maintains the state before the abnormality detection of the master unit by using the individual detection values ​​of their respective pressure sensors 2c, 3c, 4c, ..., nc.

[0058] Here, the abnormalities in the master unit (unit 1) detected by the slave units (units 2 to n) include cases where there are no abnormalities in the master unit's (unit 1) basic functions (compressed gas generation function), but an abnormality occurs in serial communication using n-1 communication lines L1 to Ln-1. In such cases, the master unit (unit 1) can supply compressed gas to the customer.

[0059] In other words, if the master unit (unit 1) is unable to properly receive device data from the slave units (units 2 to n), it switches its operating mode from the unit control mode to the independent operation mode, just like the slave units (units 2 to n), and continues independent operation using the individual detection values ​​of the first pressure sensor 1c.

[0060] Thus, in the method for controlling the number of n compressors C1 to Cn according to this embodiment, if an abnormality occurs in serial communication using n-1 communication lines L1 to LL-1, the autonomous operation of compressors 1 to n (compressors C1 to n) continues based on the individual detection values ​​of each pressure sensor 1c, 2c, 3c, 4c, ..., nc.

[0061] Furthermore, by using individually set abnormal control pressures PE (target pressure) instead of the individual detection values ​​of each pressure sensor 1c, 2c, 3c, 4c, ..., nc, a simulated multi-unit control is implemented using units 1 to n (compressors C1 to Cn, from the 1st to the nth). Figure 5 is a schematic diagram showing the above abnormal control pressures PE (target pressure). In Figure 5, for convenience, eight abnormal control pressures PE1 to PE8 for eight compressors (units 1 to 8) are shown.

[0062] In Figure 5, as an example, eight abnormal control pressures PE1 to PE8 are shown, where the lower the equipment number, the higher the target pressure PE, and conversely, the higher the equipment number, the lower the target pressure PE. However, the eight abnormal control pressures PE1 to PE8 for the eight compressors (units 1 to 8) are the upper limit pressure P H and lower pressure P L These are the individual pressure values ​​between them.

[0063] For example, the abnormal control pressures PE1 to PE8 (target pressures) are set as follows. The first setting method is to divide the supply pressure equally among the number of compressors (8 units). For example, if the total number of units is N, the upper limit pressure is PH, and the lower limit pressure is PL, the abnormal control pressure PEi of unit i (i = a natural number between 1 and 8) is given by the following equation (1).

[0064]

number

[0065] In this first setting method, the abnormal control pressures PE1 to PE8 (target pressures) may be those provided in advance from the master unit (unit 1) to each slave unit (units 2 to 8) before the abnormality occurs, or they may be those that each slave unit (units 2 to 8) calculates autonomously.

[0066] The second setting method is based on equal distribution, but with different weightings assigned to each unit (units 1 to 8). Units 1 to 8 (compressors C1 to C8, units 1 to 8) have their pressure thresholds (control thresholds) stored in advance, similar to the first setting method, and also autonomously calculate their own target pressure PE.

[0067] In the second setting method, the abnormal control pressure PEi (target pressure) is given by the following equation (2). Note that the abnormal control pressure PEi (target pressure) in the second setting method may be provided in advance from the master unit (unit 1) to each slave unit (units 2 to 8) before the abnormality occurs, or it may be calculated autonomously by each slave unit (units 2 to 8).

[0068]

number

[0069] Furthermore, the third setting method is one in which the master station (unit 1) determines the abnormal control pressure PEi (target pressure) based on a pre-set rule (abnormal control pressure setting rule). In addition to the abnormal control pressure setting rule, the master station (unit 1) sets (determines) the abnormal control pressure PEi (target pressure) based on the model and supply pressure of each unit (units 1 to 8).

[0070] Then, the master station (unit 1) broadcasts the abnormal control pressure PEi (target pressure) to each slave unit (units 2-8) before the abnormality occurs. In the third setting method, the master station (unit 1) needs to know the model of each unit (units 1-8), i.e., the compressed gas generation capacity. The master station (unit 1) sets (determines) the abnormal control pressure PEi (target pressure) by referring to specification data (specification information) that has been acquired in advance as part of the equipment data (equipment information).

[0071] In this type of compression system A, multiple (n) compressors C1 to Cn consist of a first compressor C1 (unit 1) that functions as a master unit (control entity) for unit control and n-1 compressors C2 to Cn (units 2 to n) that function as slave units (control entities) for unit control. Under normal circumstances, they share operational data (operational information) via n-1 communication lines L1 to Ln-1 (communication lines), so that even if the first compressor C1 (unit 1) that functions as the master unit (control entity) malfunctions, the n-1 compressors C2 to Cn (units 2 to n) that function as slave units (control entities) continue to supply compressed gas to the customer.

[0072] According to this embodiment, even if the first compressor C1 (unit 1), which functions as the master unit (control entity) for unit control, malfunctions, it is possible to provide a compression system A that can continue supplying compressed gas to the customer by at least n-1 compressors C2 to Cn (units 2 to n), which function as slave units (control entities).

[0073] Furthermore, in the compression system A according to this embodiment, if the first compressor C1 (unit 1), which functions as the master unit (control body), malfunctions, the n-1 compressors C2 to Cn (units 2 to n), which function as slave units (control bodies), will operate autonomously using the individual detection values ​​of their respective pressure sensors 2c, 3c, 4c, ..., nc. Therefore, according to this embodiment, it is possible to provide a compression system A that can continue supplying compressed gas to customers even if the first compressor C1 (unit 1), which functions as the master unit (control body), malfunctions.

[0074] Furthermore, in the compression system A according to this embodiment, if the first compressor C1 (unit 1), which functions as the master unit (control entity), malfunctions, the n-1 compressors C2 to Cn (units 2 to n), which function as slave units (control entities), perform simulated multi-unit control operation by using individually set abnormality control pressures PE (target pressures). Therefore, according to this embodiment, it is possible to provide a compression system A that can continue supplying compressed gas to customers even if the first compressor C1 (unit 1), which functions as the master unit (control entity), malfunctions.

[0075] Furthermore, each of the multiple (n) compressors C1 to Cn is equipped with individual pressure sensors 1c, 2c, 3c, 4c, ..., nc. If an abnormality occurs in one of its individual pressure sensors, it acquires the detection values ​​from other individual pressure sensors via n-1 communication lines L1 to Ln-1 (communication lines) to perform autonomous operation or simulated multi-unit control operation. This also makes it possible to provide a compression system A that can continue supplying compressed gas to customers even if the first compressor C1 (unit 1), which functions as the master unit (control entity), malfunctions.

[0076] Furthermore, in this compression system A, multiple (n) compressors C1 to Cn share specification data (specification information) for each compressor C1 to Cn via n-1 communication lines L1 to Ln-1 (communication lines). In other words, in this compression system A, it is not necessary to pre-input the specification data (specification information) of the n-1 compressors C2 to Cn (2 to n units) that function as slave units (control units) into the first compressor C1 (unit 1), which functions as the master unit (control entity).

[0077] According to this embodiment, the initial setup of the number of units controlled by the first compressor C1 (Unit 1), which functions as the master unit (control entity), is easy. Therefore, according to this embodiment, efficient number of units can be achieved by the first compressor C1 (Unit 1), which functions as the master unit (control entity).

[0078] The present invention is not limited to the embodiments described above, and for example, the following modifications are possible. (1) In the above embodiment, when the master unit (control entity) in the unit control system is abnormal, the slave unit (control object) in the unit control system performs autonomous operation or simulated unit control operation, but the present invention is not limited thereto.

[0079] For example, if the master unit (control entity) in a unit control system malfunctions, one of the slave units (control objects) can take over as the master unit (control entity) to continue normal unit control operation. In other words, the second to n compressors C2 to Cn (units 2 to n) that function as slave units (control objects) share the equipment data (equipment information) of the first compressor C1 (unit 1) that functions as the master unit (control entity), and can therefore take over as the master unit (control entity) for unit control from the first compressor C1 (unit 1).

[0080] In this case, the slave unit (control object) that becomes the master unit (control entity) in place of the first compressor C1 (unit 1) is selected based on a pre-set switching rule. For example, among the second to n compressors C2 to Cn (units 2 to n), the one with the smallest equipment number, i.e., the second compressor C2 (unit 2), becomes the master unit (control entity).

[0081] Furthermore, it is possible that the second compressor C2 (Unit 2), which has become the master unit (control entity) for the number of compressors in place of the first compressor C1 (Unit 1), may malfunction. In this case, one of the third to n compressors C3 to Cn (Units 3 to n) will become the next master unit (control entity). For example, the third compressor C1 (Unit 3), which has the smallest equipment number, will become the next master unit (control entity), thereby continuing normal number of compressor control.

[0082] (2) As is well known, various types of compressors are in use, such as rotary and reciprocating types. The present invention is not limited to the type of compressor, and can be applied to control multiple compressors.

[0083] (3) In the independent operation or simulated multi-unit control operation of the eight compressors (Nos. 1 to 8), a failure may occur in the pressure sensor (individual pressure sensor) that is individually equipped in each compressor (Nos. 1 to 8). In this case, compression system A will operate in response to the failure of the individual pressure sensor as shown in the flowchart of Figure 6.

[0084] Each control unit in the eight compressors (Nos. 1 to 8) sets, for example, the individual pressure sensor provided in its own compressor as a setting sensor (initial sensor) when the compression system A is in operation (step S1a). Then, each control unit determines whether or not there is an abnormality in the setting sensor (step S2a).

[0085] If the determination in step S2a is "Yes," that is, if an abnormality is detected in the setting sensor, each control unit switches the setting sensor to an individual pressure sensor provided in another compressor (step S3a). On the other hand, if the determination in step S2a is "No," that is, if no abnormality is detected in the setting sensor, each control unit continues to transmit the individual pressure to the other compressor (step S4a).

[0086] Here, each control unit switches the set sensor according to a pre-set sensor setting rule. Each control unit sets the individual pressure sensor of the other compressor with the smallest equipment number as the set sensor, for example. As shown in Figure 7, when the control unit of unit 1 malfunctions, it sets the individual pressure sensor of unit 1 as the set sensor.

[0087] (4) In the above embodiment, the case in which the collective tank T is equipped with one main pressure sensor P and each of the n compressors C1 to Cn is equipped with one pressure sensor 1c, 2c, 3c, 4c, ..., nc (individual pressure sensor), has been described, but the present invention is not limited thereto. That is, redundancy may be provided by equipping the collective tank T and the compressors C1 to Cn with one or more pressure sensors (main pressure sensor and individual pressure sensors).

[0088] Figure 8 shows an example configuration of a compression system A1 with redundant pressure sensors. In this compression system A1, the collective tank T is equipped with two main pressure sensors Pa and Pb, and each of the n compressors C1 to Cn is equipped with one pressure sensor 1c, 2c, 3c, 4c, ..., nc. The two main pressure sensors Pa and Pb are connected to the n compressors C1 to Cn via two communication lines La and Lb, allowing for serial communication.

[0089] In such a compression system A1, if one of the two main pressure sensors Pa and Pb fails, the n compressors C1 to Cn can acquire the main detection value detected by the other sensor. Therefore, with this compression system A1, even if one of the two main pressure sensors Pa and Pb fails, it is possible to continue supplying compressed gas to the customer.

[0090] (5) In the above embodiment, a case in which a collection tank T and n compressors C1 to Cn are connected via serial communication has been described, but the present invention is not limited thereto. For example, as shown in Figure 9, a compression system A2 may be adopted in which a data acquisition device D is added to the above-described compression system A1.

[0091] In other words, in this compression system A2, a data acquisition device D is connected to the compressor Cn via a communication line Ln in a manner that allows for serial communication. In such a compression system A2, the data acquisition device D remotely monitors the compression system A2 by acquiring various information shared by the collective tank T and the n compressors C1 to Cn via the communication line Ln. With this modified configuration, it is possible to easily grasp the operating status of the compression system A2. [Explanation of Symbols]

[0092] A, A1, A2 Compression System C1~Cn Compressor, D Data Acquisition Device H Collective piping L1~Ln-1 communication lines P, Pa, Pb main pressure sensor T collection タンク 1a, 2a, 3a, 4a, ..., na (Main Body) 1b, 2b, 3b, 4b, ..., nb Control Department 1c, 2c, 3c, 4c, ..., nc pressure force センサ (individual pressure force センサ)

Claims

1. Communication lines and The system comprises multiple compressors interconnected by the communication line and supplying compressed gas to customers at a predetermined supply pressure, A compression system characterized in that a plurality of compressors consist of a control entity and a control object for number control, and under normal circumstances, they share operational information via the communication line, so that if the control entity malfunctions, the control object continues to supply the compressed gas.

2. The compression system according to claim 1, characterized in that when the controlled object detects an abnormality in the control entity via the communication line, it cancels the unit control and continues to supply the compressed gas by performing autonomous operation.

3. The compression system according to claim 1, characterized in that when the controlled object detects an abnormality in the control entity via the communication line, it continues to supply the compressed gas by performing simulated multi-unit control operation using individually set target pressures.

4. The compression system according to claim 2 or 3, wherein each of the multiple compressors is equipped with an individual pressure sensor for detecting the pressure of the compressed gas, and when an abnormality occurs in one of the individual pressure sensors, it is characterized in that it performs autonomous operation or operation by number of units control by obtaining the detected values ​​of other individual pressure sensors via the communication line.

5. The compression system according to claim 1 or 2, characterized in that the multiple compressors share specification information via the communication line.

6. The system includes a collection tank T connected to multiple compressors via a collection pipe H, The collection tank T is equipped with one or more main pressure sensors for detecting the supply pressure, The compression system according to claim 1 or 2, characterized in that the plurality of compressors are equipped with one or more individual pressure sensors for detecting the pressure of the compressed gas sent to the collective piping.

7. The compression system according to claim 6, characterized in that the main pressure sensor transmits the supply pressure to a plurality of compressors via the communication line.

8. The compression system according to claim 1 or 2, further comprising a data acquisition device that performs mote monitoring by acquiring the aforementioned operation information via the communication line.

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