compressor

Abstract

To suppress a decrease in the operating rate of a compressor when a test run of a predetermined compressor unit is performed. [Solution] The compressor includes a plurality of compressor units, each having a compressor body that compresses gas and a motor that drives the compressor body, piping that connects the plurality of compressor units, and a control device that controls the plurality of compressor units. The control device stops operation of a compressor unit that satisfies an abnormal stop condition among the plurality of compressor units, and performs a test run of the compressor unit that satisfies the abnormal stop condition while continuing the number-controlled operation of the other compressor units.

Description

Technical Field

[0001] The present invention relates to a compressor.

Background Art

[0002] Compressors are known that generate compressed gas used as a power source for pneumatic actuators of machine tools such as presses in a manufacturing line, and compressed gas used in pneumatic tools such as air blow guns and air drills. Patent Document 1 describes that a plurality of compressor units (compression modules) are connected in parallel, and while the operation of the system continues, only the compressor unit to be maintained can be put into a stopped state and the compressor unit can be maintained.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technology described in Patent Document 1, when maintaining a compressor unit stopped due to abnormal detection or the like, the operation of other compressor units can be continued during maintenance. However, Patent Document 1 does not disclose any control of the compressor unit when performing a test operation to confirm whether the compressor unit stopped due to abnormal detection or the like operates normally.

[0005] Generally, in a compressor system with multiple compressor units powered by the same power source, if a compressor unit fails, the operation of the faulty unit is stopped. After inspection and replacement, the compressor unit is test-run and then put back into normal operation. At this time, since all compressor units receive power from the same power source, even if the operation of the compressor unit is stopped, its components remain energized. Performing component replacement while the components are energized could endanger the safety of the workers, so in many cases, the entire compressor is stopped before replacing the faulty part.

[0006] However, depending on the type of malfunction, it may not be necessary to replace parts or perform a physical inspection. Even in this case, if the entire compressor needs to be shut down, there is room for improvement in terms of increasing the compressor's operating efficiency. [Means for solving the problem]

[0007] A compressor according to one aspect of the present invention comprises a plurality of compressor units, each having a compressor body for compressing a gas and a motor for driving the compressor body, piping connecting the plurality of compressor units, and a control device for controlling the plurality of compressor units. An operation panel or external information terminal for inputting commands to the control device, and a housing that houses a plurality of the compressor units, the control device, and the piping, and has the operation panel on its surface, This includes: The control device stops the operation of the compressor unit that has met the abnormal stop condition among the plurality of compressor units, and while continuing the number control operation of the other compressor units, it performs a trial run of the compressor unit that has met the abnormal stop condition. The process involves restarting the compressor unit that has been stopped after the trial run is completed, and returning to the unit-controlled operation. The trial run is an operation that limits the operating time or rotational speed. The process of restarting the compressor unit that has been stopped after the trial run is performed after the control device receives a command from the operation panel or the external information terminal indicating that there is no abnormality. cormorant. [Effects of the Invention]

[0008] According to the present invention, if a predetermined compressor unit among multiple compressor units stops due to meeting abnormal stop conditions, a trial run of that predetermined compressor unit can be performed without interfering with the operation of the other compressor units under control. Since the trial run of the predetermined compressor unit does not interfere with the operation of the other compressor units under control, the operating rate of the compressors can be improved. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a diagram showing the configuration of a compressor according to the first embodiment. [Figure 2] Figure 2 is a schematic cross-sectional view of the compressor unit. [Figure 3] Figure 3 is a diagram illustrating how to operate the compressor. [Figure 4] Figure 4 is a flowchart illustrating an example of the number of units controlled by the control device. [Figure 5] Figure 5 is a flowchart illustrating the control process for stopping the compression module when a stop condition is met during unit control. [Figure 6] Figure 6 is a flowchart illustrating the control process for commissioning the compression module and returning to unit control during unit control. [Figure 7] Figure 7 is a flowchart showing the control process when a trial run mode is set using a control device according to a modified example of the first embodiment. [Figure 8] Figure 8 shows the configuration of a compressor according to the second embodiment. [Figure 9] Figure 9 shows a target rotational speed table used for motor speed control by a control device according to a modified example of the second embodiment. [Figure 10] Figure 10 is a diagram showing the configuration of a compressor according to the third embodiment. [Figure 11] Figure 11 is a flowchart showing the control process when the trial run mode is set by the control device according to the third embodiment. [Figure 12] Figure 12 shows the relationship between the stop flag stored in the control device according to Modification Example 1 and whether or not the trial run process can be executed. [Modes for carrying out the invention]

[0010] A compressor according to an embodiment of the present invention will be described with reference to the drawings.

[0011] <First Embodiment> Figure 1 is a diagram showing the configuration of a compressor 10 according to the first embodiment of the present invention. As shown in Figure 1, the compressor 10 according to the first embodiment of the present invention comprises three compression modules 101A, 101B, and 101C that generate compressed gas such as compressed air, a main discharge pipe 105 to which the compressed gas discharged from the three compression modules 101A, 101B, and 101C is supplied, a second aftercooler 142 provided in the main discharge pipe 105, a third aftercooler 143 provided downstream of the second aftercooler 142 in the main discharge pipe 105, a dryer 144 provided downstream of the third aftercooler 143 in the main discharge pipe 105, a pressure sensor 131 provided downstream of the dryer 144 in the main discharge pipe 105, a control device (control board) 180 that controls the number of the three compression modules 101A, 101B, and 101C, and a package housing 11 that houses most of these components.

[0012] Multiple compression modules 101A, 101B, 101C, a control device 180, and other electrical components housed within the package enclosure 11 are all supplied with power from the same power source (not shown) outside the package enclosure 11. The power supply path from the power source branches out within the package enclosure 11 and connects to the multiple compression modules 101A, 101B, 101C, the control device 180, and other electrical components.

[0013] Since the three compression modules 101A, 101B, and 101C have the same configuration, they are collectively referred to as the compression module 101. The compression module 101 includes a compressor unit 100 having a compressor body 110 and a motor 120, an electromagnetic switch 140 for switching the supply and cutoff of power to the motor 120, a filter 150 connected to the suction port of the compressor body 110 for capturing foreign matter, a module pipe 104 to which the compressed gas discharged from the compressor body 110 is supplied, a check valve 151 provided in the module pipe 104, and a first aftercooler 141 provided on the downstream side of the check valve 151 in the module pipe 104. The check valve 151 allows the flow of gas from the compressor body 110 toward the first aftercooler 141 and prohibits the flow of gas from the first aftercooler 141 toward the compressor body 110. Therefore, the check valve 151 prevents the compressed gas from flowing backward from the main discharge pipe 105 side into the compressor body 110 when the compression module 101 stops. The module pipes 104 of the three compression modules 101 are connected to the same main discharge pipe 105.

[0014] An electromagnetic switch 140, a dryer 144, an operation panel 170, a communication device 190, a pressure sensor 131, a temperature sensor 132, and an ambient temperature sensor 133 are connected to the control device 180. The pressure sensor 131 detects the discharge pressure of the compressor 10 and outputs the detection result to the control device 180. The temperature sensor 132 detects the temperature of the compressor body 110 and outputs the detection result to the control device 180. The ambient temperature sensor 133 detects the temperature around the compressor 10 and outputs the detection result to the control device 180.

[0015] The control device 180 is composed of a computer including a processor 181 such as a CPU (Central Processing Unit), MPU (Micro Processing Unit), DSP (Digital Signal Processor), a non-volatile memory 182 such as a ROM (Read Only Memory), flash memory, and a hard disk drive which is a magnetic storage device, a volatile memory 183 called a so-called RAM (Random Access Memory), an input interface, an output interface, and other peripheral circuits. Note that the control device 180 may be composed of one computer or a plurality of computers.

[0016] The non-volatile memory 182 stores information such as programs and data necessary for executing various processes, including a control program for realizing the number control and the like. That is, the non-volatile memory 182 is a storage medium (storage device) capable of reading a program for realizing the functions of the present embodiment. The processor 181 is a processing device that develops the program stored in the non-volatile memory 182 in the volatile memory 183 and executes calculations, and performs predetermined arithmetic processing on the data taken in from the input interface, the non-volatile memory 182, and the volatile memory 183 according to the program.

[0017] The input interface converts the signals input from the operation panel 170, the communication device 190, the pressure sensor 131, the temperature sensor 132, the ambient temperature sensor 133, the electromagnetic switch 140, etc. into data that can be calculated by the processor 181. Further, the output interface generates an output signal according to the calculation result of the processor 181, and outputs the signal to the electromagnetic switch 140, the dryer 144, the communication device 190, etc.

[0018] The control device 180 controls the first electromagnetic switch 140A to operate the first compressor unit 100A at a constant speed or to stop it. The control device 180 controls the second electromagnetic switch 140B to operate the second compressor unit 100B at a constant speed or to stop it. The control device 180 controls the third electromagnetic switch 140C to operate the third compressor unit 100C at a constant speed or to stop it. The electromagnetic switch 140 has an electromagnetic contactor and a thermal relay. The thermal relay detects an overcurrent flowing to the motor 120 and activates its contacts to stop the motor 120. This prevents the motor 120 from burning out. The overcurrent detection signal from the thermal relay is output to the control device 180. The control device 180 detects the overcurrent in the motor 120 based on the detection signal from the thermal relay.

[0019] The compressed gas discharged from the compressor unit 100 passes through the check valve 151 and is supplied to the first aftercooler 141. The compressed gas cooled in the first aftercooler 141 is supplied to the main discharge pipe 105 via the module piping 104. In other words, the compressed gas discharged from the first to third compressor units 100A to 100C merge in the main discharge pipe 105 and is supplied to the second aftercooler 142, where it is cooled. The compressed gas cooled in the second aftercooler 142 is supplied to the third aftercooler 143, where it is cooled. The compressed gas cooled in the third aftercooler 143 is supplied to the dryer 144. The dryer 144 dehumidifies the compressed gas by heat exchange with cooling air. In other words, the dryer 144 is a heat exchanger that removes condensate from the compressed gas. The compressed gas dehumidified in the dryer 144 is led from the device outlet to an external tank (not shown). Although not shown in the diagram, the tank is connected to pneumatic equipment via output piping, and compressed gas is supplied to the pneumatic equipment by opening and closing a valve device provided in the output piping. Pneumatic equipment includes, for example, pneumatic actuators used in machine tools, and air tools such as air blow guns and air drills.

[0020] Referring to Figure 2, the configuration of the compressor unit 100 will be described. Figure 2 is a schematic cross-sectional view of the compressor unit 100. As shown in Figure 2, the compressor unit 100 includes a compressor body 110 for compressing a gas such as air, a motor 120 for driving the compressor body 110, and a cooling fan 130 for generating cooling air. The compressor body 110 in this embodiment compresses the gas using a compression method called the scroll method. The compressor body 110 has a fixed scroll 111 and an orbiting scroll 112 arranged opposite each other, and a compression chamber 113 is formed between the fixed scroll 111 and the orbiting scroll 112, and the air in the compression chamber 113 is compressed by orbiting motion.

[0021] The fixed scroll 111 includes a disc-shaped end plate 111a, a spiral-shaped wrap portion 111b that protrudes from the end plate 111a toward the motor 120, and a plurality of cooling fins 111c that protrude from the end plate 111a toward the opposite side from the motor 120.

[0022] The orbiting scroll 112 includes a disc-shaped end plate 112a, a spiral-shaped wrap portion 112b that protrudes from the end plate 112a toward the fixed scroll 111, and a plurality of cooling fins 112c that protrude from the end plate 112a toward the motor 120.

[0023] The tip surface of the lap portion 111b of the fixed scroll 111 is provided with a tip seal 111d, which is a sealing member that seals the space between the tip surface of the lap portion 111b and the end plate 112a of the orbiting scroll 112. The tip surface of the lap portion 112b of the orbiting scroll 112 is provided with a tip seal 112d, which is a sealing member that seals the space between the tip surface of the lap portion 112b and the end plate 111a of the fixed scroll 111.

[0024] The compression chamber 113 is formed between the overlapping portion 111b of the fixed scroll 111 and the overlapping portion 112b of the orbiting scroll 112, and is airtightly held in place by tip seals 111d and 112d. As the orbiting scroll 112 orbits in the forward direction, the compression chamber 113 moves from the radially outer to the radially inner side of the overlapping portions 111b and 112b, and is continuously contracted between the overlapping portions 111b and 112b. As a result, the gas supplied to the compression chamber 113 from the outside is compressed, and the compressed gas is discharged from the discharge port in the center of the overlap into the module piping 104 (see Figure 1).

[0025] The motor 120 comprises a stator 121 with stator coils mounted on a stator core, a rotor 122 positioned with an air gap between it and the stator 121, and a shaft 123 fixed to the rotor 122. The stator 121 and rotor 122 are housed within a motor housing, and the shaft 123 is rotatably supported by bearings 124A and 124B provided in the motor housing. AC power supplied from a power source (not shown) is supplied to the stator coils via an electromagnetic switch 140, forming a rotating magnetic field, which causes the rotor 122 to rotate together with the shaft 123.

[0026] In this embodiment, the motor 120 is an axial gap type motor that drives the compressor body 110 coaxially, but the type of motor 120 is not limited to this. The motor 120 may also be a radial gap type such as an inner rotor type or an outer rotor type, or a linear type.

[0027] The power of the motor 120 is transmitted to the orbiting scroll 112 and the cooling fan 130 via the shaft 123. As the motor 120 rotates, the orbiting scroll 112 rotates and compresses the gas, and as the cooling fan 130 rotates, cooling air is generated. The cooling air flows toward the motor 120 and the compressor body 110, cooling the motor 120 and the compressor body 110. In addition, a member (such as a duct) that guides the cooling air generated by the cooling fan 130 may be provided so that it flows toward the cooling fins 111c of the fixed scroll 111 and the cooling fins 112c of the orbiting scroll 112.

[0028] A temperature sensor 132 for detecting the temperature of the compressor body 110 is attached to the cooling fin 111c of the fixed scroll 111.

[0029] Referring to Figure 3, the operation method of the compressor 10 will be explained. As shown in Figure 3, an operation panel 170 is mounted on the front side of the package housing 11 of the compressor 10. The operation panel 170 has multiple display units 171a, 171b for informing the user of the status of the compressor 10. Display unit 171a is a digital display such as a liquid crystal display and displays the discharge pressure of the compressor 10 detected by the pressure sensor 131, the operating time of the compressor 10, etc. Display unit 171a may also be a 7-segment display having multiple 7-segment LEDs (light-emitting diodes). Multiple display units 171b are composed of LEDs, etc. The display units 171b light up or flash in predetermined colors to inform the user of the operating status of the compressor 10, the selected control mode, whether or not there is a malfunction in the compressor 10, etc.

[0030] The control panel 170 has a plurality of operation switches 172a to 172d that are operated by the user. The plurality of operation switches 172a to 172d include an operation switch 172a for instructing the start of operation, a stop switch 172b for instructing the stop of operation, a menu switch 172c for instructing the change of settings, and a display switching switch 172d for switching the display content of the display unit 171a.

[0031] The user can start, stop, change settings, and switch the display content of the display unit 171a of the compressor 10 by operating the operation switches 172a to 172d on the control panel 170. In this embodiment, the compressor 10 can be operated using an information terminal 90 that communicates wirelessly with the compressor 10. The information terminal 90 is a variety of portable devices that the user can carry, such as a smartphone, tablet, or wearable device.

[0032] The information terminal 90 has a compressor application installed for monitoring the operating status of the compressor 10 and for remotely operating the compressor 10. The compressor 10 and the information terminal 90 exchange information with each other via wireless communication. The communication device 190 of the compressor 10 (see Figure 1) has a communication interface that includes a communication antenna with a predetermined frequency band as its sensitive band.

[0033] Various methods can be used for communication between the compressor 10 and the information terminal 90. For example, the compressor 10 and the information terminal 90 may exchange information via a wide-area network communication line 8. The communication line 8 may be the Internet, a mobile phone network such as 4G or 5G, a LAN (Local Area Network), or a WAN (Wide Area Network). Alternatively, Bluetooth® can be used as a short-range wireless communication method that allows the compressor 10 and the information terminal 90 to exchange information directly without using the communication line 8. The short-range wireless communication method is not limited to Bluetooth; other communication methods such as Wi-Fi® and ZigBee® can also be used.

[0034] The information terminal 90 can control the operation of the compressor 10 by launching the installed compressor application and performing predetermined operations on the information terminal 90's touch panel 93. The information terminal 90 displays the same content as the display units 171a and 171b of the operation panel 170 in the status display area 91 of the touch panel 93, which functions as both a display and input unit. In addition, the information terminal 90 displays the same operation switches 92a, stop switch 92b, menu switch 92c, and display switching switch 92d as the operation switches 172a to 172d of the operation panel 170 in the operation area 92 of the touch panel 93. The user of the information terminal 90 can start or stop the operation of the compressor 10, change settings, or switch the display content of the touch panel 93 by touching the operation switches 92a to 92d.

[0035] The information terminal 90 may be a dedicated information terminal that only operates and monitors the compressor 10. In this case, the operation panel 170, which is detachable from the package housing 11, can also be used as the information terminal 90. The operation method using the operation panel 170 and the operation method using the information terminal 90 are the same. Therefore, in the following, the control contents of the control device 180 based on the operation of the operation panel 170 will be described as a representative example, and the control contents of the control device 180 based on the operation of the information terminal 90 will not be described.

[0036] The control of the number of units performed by the control device 180 will be explained with reference to Figures 1 and 4. The control device 180 shown in Figure 1 has the function of storing the pressure detected by the pressure sensor 131, the function of measuring and storing the cumulative operating time of each compressor unit 100, and the function of starting and stopping the motor 120. The pressure sensor 131 is installed in the main discharge pipe 105 connected to a tank (not shown). In other words, the pressure detected by the pressure sensor 131 is approximately the same as the pressure inside the tank.

[0037] The control device 180 outputs operation commands to the electromagnetic switches 140A to 140C, and by operating the electromagnetic switches 140A to 140C, it rotates the motors 120 of the compressor units 100A to 100C at a constant speed. The control device 180 can operate the compression modules 101A to 101C individually by outputting operation commands to each of the electromagnetic switches 140A to 140C individually. For example, the control device 180 can select and operate one of the compression modules 101A to 101C, select and operate two of the compression modules 101A to 101C, or select and operate all of the compression modules 101A to 101C.

[0038] In unit control, the control device 180 controls the number of operating compression modules 101 so that the pressure detected by the pressure sensor 131 is maintained within the pressure range from the lower limit pressure Pmin to the upper limit pressure Pmax. The upper limit pressure Pmax and lower limit pressure Pmin are stored in advance in the non-volatile memory 182. The upper limit pressure Pmax and lower limit pressure Pmin stored in the non-volatile memory 182 can be changed by operating the operation panel 170.

[0039] Figure 4 is a flowchart showing an example of the number of units controlled by the control device 180. The process shown in the flowchart in Figure 4 is started when the operation switch 172a is operated, and after initial setup, it is repeatedly executed at a predetermined sampling period Ts (for example, 200 ms).

[0040] In step S10, the control device 180 acquires the pressure P(t) detected by the pressure sensor 131 and proceeds to step S15. In step S15, the control device 180 determines whether the pressure P(t) acquired in step S10 is less than the lower limit pressure Pmin. If it is determined in step S15 that the pressure P(t) is less than the lower limit pressure Pmin, the process proceeds to step S20. In step S20, the control device 180 starts up all compression modules 101A to 101C and terminates the process shown in the flowchart of Figure 4 for this calculation cycle. That is, it proceeds to step S10 of the next calculation cycle, which is executed after the sampling period Ts has elapsed.

[0041] In step S15, if it is determined that the pressure P(t) is greater than or equal to the lower limit pressure Pmin, the process proceeds to step S25. In step S25, the control device 180 determines whether the pressure P(t) obtained in step S10 is greater than or equal to the upper limit pressure Pmax. In step S25, if it is determined that the pressure P(t) is greater than or equal to the upper limit pressure Pmax, the process proceeds to step S30. In step S30, the control device 180 stops all compression modules 101A to 101C and terminates the process shown in the flowchart of Figure 4 for this calculation cycle. That is, the process proceeds to step S10 of the next calculation cycle, which is executed after the sampling period Ts has elapsed.

[0042] In step S25, if it is determined that the pressure P(t) is less than the upper limit pressure Pmax, the process proceeds to step S35. In step S35, the control device 180 uses the pressure P(t-1) obtained in step S10 of the previous calculation cycle and the pressure P(t) obtained in step S10 of the current calculation cycle to calculate the pressure change rate K using the following equation (1). K = (P(t) - P(t-1)) / Ts …(1) The pressure change rate K is the rate of change over time of the discharge pressure of the compressor 10.

[0043] Once the calculation of the pressure change rate K (step S35) is completed, the process proceeds to step S40. In step S40, the control device 180 determines whether the pressure change rate K calculated in step S35 is a negative value. If it is determined in step S40 that the pressure change rate K is a negative value, i.e., the discharge pressure is decreasing, the process proceeds to step S50. If it is determined in step S40 that the pressure change rate K is not a negative value, the process proceeds to step S45.

[0044] In step S50, the control device 180 calculates the predicted time Td until the lower limit pressure Pmin is reached from the present moment by dividing the difference between the lower limit pressure Pmin and the current pressure P(t) obtained in step S10 by the pressure change rate K calculated in step S35, as shown in equation (2) below. Td = (Pmin - P(t)) / K …(2) Once the calculation of the predicted time Td (step S50) is complete, the process proceeds to step S60.

[0045] In step S60, the control device 180 determines whether the predicted time Td is less than a predetermined first time threshold Td1 (for example, 2 seconds). The first time threshold Td0 is stored in the non-volatile memory 182. If, in step S60, it is determined that the predicted time Td is less than the first time threshold Td0, the process proceeds to step S70. If, in step S60, it is determined that the predicted time Td is greater than or equal to the first time threshold Td0, the process shown in the flowchart of Figure 4 for this calculation cycle is terminated.

[0046] In step S70, the control device 180 decides to increase the number of operating compression modules 101 by one and proceeds to step S80. In step S80, the control device 180 prioritizes starting the compression module 101 with the shortest cumulative operating time that is currently stopped, and terminates the process shown in the flowchart of Figure 4 for this calculation cycle.

[0047] In step S45, the control device 180 determines whether the pressure change rate K calculated in step S35 is a positive value. If it is determined in step S45 that the pressure change rate K is a positive value, that is, the discharge pressure is increasing, the process proceeds to step S55. If it is determined in step S45 that the pressure change rate K is not a positive value, that is, the pressure change rate K is 0 and there is no pressure change, the process shown in the flowchart of Figure 4 for this calculation cycle is terminated.

[0048] In step S55, the control device 180 calculates the predicted time Tu from the present until the upper limit pressure Pmax is reached by dividing the difference between the upper limit pressure Pmax and the current pressure P(t) obtained in step S10 by the pressure change rate K calculated in step S35, as shown in equation (3) below. Tu = (Pmax - P(t)) / K …(3) Once the calculation of the predicted time Tu (step S55) is complete, the process proceeds to step S65.

[0049] In step S65, the control device 180 determines whether the predicted time Tu is less than a predetermined second time threshold Tu0 (for example, 5 seconds). The second time threshold Tu0 is stored in the non-volatile memory 182. If, in step S65, it is determined that the predicted time Tu is less than the second time threshold Tu0, the process proceeds to step S75. If, in step S65, it is determined that the predicted time Tu is greater than or equal to the second time threshold Tu0, the process shown in the flowchart of Figure 4 for this calculation cycle is terminated.

[0050] In step S75, the control device 180 decides to reduce the number of operating compression modules 101 by one and proceeds to step S85. In step S85, the control device 180 prioritizes stopping the compression module 101 with the longest cumulative operating time and terminates the process shown in the flowchart of Figure 4 for this calculation cycle.

[0051] As described above, the control device 180 according to this embodiment controls the number of operating compression modules 101 based on the pressure P(t) which changes according to the amount of air used. The control device 180 can reduce unnecessary power consumption by reducing the number of operating compression modules 101 before the upper limit pressure Pmax is exceeded. In addition, the control device 180 can appropriately supply the required amount of air to the pneumatic equipment by increasing the number of operating compression modules 101 before the lower limit pressure Pmin is exceeded. The control device 180 prioritizes starting compression modules 101 with short cumulative operating times and prioritizes stopping compression modules 101 with long cumulative operating times. As a result, the cumulative operating time of each compression module 101 can be averaged. Consequently, by performing maintenance on each compression module 101 in parallel at the same time, the amount of time the compressor 10 is not operating can be minimized.

[0052] Note that the processing flow for the number of units control is not limited to the example shown in Figure 4. The number of units control is any control that can generate the desired pressure using multiple compression modules 101, and various forms of processing flow can be adopted. For example, the control device 180 may perform a number of units control that repeatedly performs the following processes: simultaneously starting up multiple compression modules 101 subject to number of units control when the pressure P(t) detected by the pressure sensor 131 falls below the lower limit pressure Pmin, and simultaneously stopping multiple compression modules 101 subject to number of units control when the pressure P(t) detected by the pressure sensor 131 becomes equal to or greater than the upper limit pressure Pmax.

[0053] The control device 180 individually determines whether there is a malfunction in any of the multiple compression modules 101. If the control device 180 determines that there is a malfunction in a compression module 101, it sets a stop flag on the compression module 101 that has been determined to be malfunctioning. While continuing to control the number of units for the compression modules 101 that do not have a stop flag set, the control device 180 performs an exclusion process to stop the compression modules 101 that have a stop flag set and exclude them from the number of units control. In this way, by stopping the compression modules 101 that the control device 180 has determined to be malfunctioning and excluding them from the number of units control, further wear and tear on the compression modules 101 (deterioration of chip seals 111d, 112d, damage to check valves 151, etc.) can be prevented. Note that in the exclusion process, the control device 180 may stop the compression modules 101 that have a stop flag set and then exclude them from the number of units control, or it may exclude the compression modules 101 that have a stop flag set from the number of units control and then stop them.

[0054] Furthermore, the control device 180 displays information about the compression module 101 for which the stop flag is set on the display units 171a and 171b. A compression module 101 for which the stop flag is set, that is, a compression module 101 that has stopped due to the setting of the stop flag, cannot return to the unit control until the stop flag is removed.

[0055] The user can learn, through the display modes of the display units 171a and 171b, that the compression module 101 has stopped due to the detection of an abnormality, etc., and the reason for the stop (for example, the nature of the abnormality). Abnormalities detected by the control device 180 according to this embodiment include temperature abnormalities and current abnormalities. In addition, the control device 180 according to this embodiment sets a stop flag not only when an abnormality is detected, but also when the cumulative operating time of the compression module 101 reaches the maintenance time. The conditions for stopping the compression module 101 during the execution of unit control (hereinafter also referred to as stop conditions) will be described in detail below.

[0056] The control device 180 determines whether the following first to third stop conditions are met. If any of the first to third stop conditions are met, the control device 180 sets a stop flag and stops the compression module 101 for which the stop flag has been set. (First stop condition) The temperature difference ΔT, which is the difference between the temperature T1 of the compressor body 110 and the ambient temperature T2 of the compressor 10, is greater than or equal to the temperature threshold T0. In other words, a temperature anomaly has occurred. (Second stop condition) Overcurrent has been detected by the thermal relay. In other words, a current anomaly has occurred. (Third stop condition) Cumulative operating time has reached the maintenance time. As mentioned above, the multiple stop conditions (first to third stop conditions) include stop conditions (first and second stop conditions) that are met when there is an abnormality in the compressor unit 100.

[0057] The process by which the control device 180 determines whether the first stop condition is met is equivalent to the process of determining whether there is a temperature anomaly. When the tip seals 111d and 112d deteriorate over time, compressed gas leaks from the compression chamber 113 through the tip seals 111d and 112d, and is then drawn back into the compression chamber 113 and compressed again, causing the temperature of the compressed gas to rise above normal. In other words, when the tip seals 111d and 112d deteriorate and seal leakage occurs, the control device 180 detects a temperature anomaly.

[0058] In this embodiment, we describe an example in which a temperature anomaly is determined based on the difference between the temperature of the compressor body 110 and the ambient temperature of the compressor 10. However, it is also possible to determine whether a temperature anomaly has occurred based solely on the temperature of the compressor body 110. However, the temperature of the compressor body 110 is affected by the environment in which the compressor 10 is installed. For example, if the temperature of the room in which the compressor 10 is installed is high, the temperature of the compressor body 110 will be higher than when the room temperature is low. Therefore, as in this embodiment, by determining whether a temperature anomaly has occurred based on the difference between the ambient temperature (room temperature) of the compressor 10 and the temperature of the compressor body 110, it is possible to detect temperature anomalies with high accuracy.

[0059] Furthermore, although this embodiment describes an example in which the temperature sensor 132 is installed on the cooling fin 111c, the temperature sensor 132 may be installed in a location other than the cooling fin 111c as long as it can detect the temperature of a part that has a certain relationship with the temperature inside the compression chamber 113.

[0060] The process by which the control device 180 determines whether the second stop condition is met is equivalent to the process of determining whether there is a current abnormality. As described above, when the tip seals 111d and 112d deteriorate over time, compressed gas may leak from the compression chamber 113 through the tip seals 111d and 112d and be drawn back into the compression chamber 113 and compressed again. When compressed gas flows from the high-pressure side compression chamber 113 to the low-pressure side compression chamber 113, the force required to drive the compressor body 110 increases. In this case, the motor drive current rises above normal. In other words, when the tip seals 111d and 112d deteriorate and seal leakage occurs, the control device 180 detects a current abnormality.

[0061] Furthermore, if the overlapping sections 111b and 112b deform due to aging or other reasons, the overlapping section 111b of the fixed scroll 111 and the overlapping section 112b of the orbiting scroll 112 may come into contact. When the overlapping sections come into contact, the force required to drive the compressor body 110 increases. In this case, the motor drive current rises above normal levels. In other words, if the overlapping sections 111b and 112b deteriorate and contact occurs between them, the control device 180 detects a current anomaly.

[0062] Furthermore, if bearings 124A and 124B deteriorate over time, the force required to drive the compressor body 110 increases, causing the motor drive current to rise above normal levels. In other words, when bearings 124A and 124B deteriorate, the control device 180 detects an abnormal current.

[0063] In this embodiment, an example is described in which a current abnormality is detected based on the operation of a thermal relay provided in the electromagnetic switch 140. However, the current in the power line connecting the electromagnetic switch 140 and the motor 120 may be detected by a current sensor, and a current abnormality may be detected based on the detection result. However, if a current sensor is provided, the cost of the compressor 10 will increase accordingly. For this reason, by configuring the system to detect current abnormalities based on the operation of the thermal relay in the electromagnetic switch 140, as in this embodiment, the cost of the compressor 10 can be reduced.

[0064] If the first stop condition is met, the control device 180 sets the temperature abnormality stop flag Ft(j) as the stop flag (Ft(j)=1). If the second stop condition is met, the control device 180 sets the current abnormality stop flag Fi(j) as the stop flag (Fi(j)=1). If the third stop condition is met, the control device 180 sets the maintenance stop flag Fm(j) as the stop flag (Fm(j)=1). Note that j is a number from 1 to 3 used to identify the first to third compression modules 101A to 101C. For example, j=1 for the stop flag associated with the first compression module 101A, j=2 for the stop flag associated with the second compression module 101B, and j=3 for the stop flag set for the third compression module 101C.

[0065] The control device 180 calculates the difference (hereinafter referred to as the temperature difference) ΔT(j) between the temperature T1(j) of the compressor body 110 detected by the temperature sensor 132 and the ambient temperature T2 of the surrounding area of ​​the compressor 10 detected by the ambient temperature sensor 133 (ΔT(j) = T1(j) - T2). The control device 180 calculates the temperature difference ΔT(j) for each compression module 101. In other words, the control device 180 calculates the difference between the temperature T1(1) detected by the first temperature sensor 132A and the temperature T2 detected by the ambient temperature sensor 133 as the temperature difference ΔT(1) of the first compression module 101A. Similarly, the control device 180 calculates the difference between the temperature T1(2) detected by the second temperature sensor 132B and the temperature T2 detected by the ambient temperature sensor 133 as the temperature difference ΔT(2) of the second compression module 101B. Furthermore, the control device 180 calculates the difference between the temperature T1(3) detected by the third temperature sensor 132C and the temperature T2 detected by the ambient temperature sensor 133 as the temperature difference ΔT(3) of the third compression module 101C.

[0066] The control device 180 determines whether the temperature difference ΔT(j) of each compression module 101 is greater than or equal to the temperature threshold T0. The temperature threshold T0 is stored in advance in the non-volatile memory 182. If the temperature difference ΔT(j) is less than the temperature threshold T0, the control device 180 determines that the first stop condition is not met and maintains the temperature abnormality stop flag Ft(j) in an unset state (Ft(j)=0). If the temperature difference ΔT is greater than or equal to the temperature threshold T0, the control device 180 determines that the first stop condition is met and sets the temperature abnormality stop flag Ft(j) (Ft(j)=1). The temperature abnormality stop flag Ft(j) is a stop flag that indicates that a temperature abnormality has been detected in the compressor unit 100 of the compression module 101, and is set in association with the compression module 101 for which the first stop condition has been determined to be met.

[0067] The control device 180 determines whether or not an overcurrent has been detected by the thermal relay of the electromagnetic switch 140, based on the overcurrent detection signal from the thermal relay of the electromagnetic switch 140. If the thermal relay has not detected an overcurrent, the control device 180 determines that the second stop condition has not been met and maintains the current abnormal stop flag Fi(j) in an unset state (Fi(j)=0). If the thermal relay has detected an overcurrent, the control device 180 determines that the second stop condition has been met and sets the current abnormal stop flag Fi(j) (Fi(j)=1). The current abnormal stop flag Fi(j) is a stop flag that indicates that an overcurrent has been detected in the compressor unit 100 of the compression module 101, and is set in association with the compression module 101 for which the second stop condition has been determined to be met.

[0068] The control device 180 determines whether the cumulative operating time to has reached the maintenance time to0. The maintenance time to0 is stored in the non-volatile memory 182 beforehand. If the cumulative operating time to is less than the maintenance time to0, the control device 180 determines that the third stop condition has not been met and maintains the maintenance stop flag Fm(j) in an unset state (Fm(j)=0). If the cumulative operating time to is equal to or greater than the maintenance time to0, the control device 180 determines that the third stop condition has been met and sets the maintenance stop flag Fm(j) (Fm(j)=1). The maintenance stop flag Fm(j) is a stop flag that indicates that the maintenance time has been reached and is set in association with the compression module 101 for which the third stop condition has been determined to be met.

[0069] As described above, a compression module 101 with a stop flag set will not be included in the unit control unless the stop flag is removed. The control device 180 performs a test run of the stopped compression module 101 based on the operation command from the operation panel 170. If the user confirms that there are no abnormalities during the test run, the user performs an operation to remove the stop flag. This removes the stop flag and allows the compression module 101 that underwent the test run to be returned to the unit control.

[0070] In this embodiment, the control device 180 continues to control the number of compression modules 101 for which the stop flag is not set, while restarting the compression modules 101 for which the stop flag is set and performing a trial run process for a predetermined time. In other words, the control device 180 continues to control the number of compression modules 101 that are subject to the number control, while starting up compression modules 101 that are not subject to the number control. For example, the control device 180 continues to control the number of compression modules 101 for which it has determined there is no temperature abnormality, while restarting the compression modules 101 for which it has determined there is a temperature abnormality.

[0071] Furthermore, the control device 180 prevents the release of the stop flag setting if the trial run process has not been completed after the exclusion process has been executed, and allows the release of the stop flag setting if the trial run process has been completed after the exclusion process has been executed.

[0072] The following will explain in detail the control process for stopping the compression module 101 when a stop condition is met during unit count control, with reference to Figure 5. As described above, when the operation switch 172a is operated, the unit count control of the control device 180 is executed (step S1 in Figure 5, flowchart in Figure 4). As shown in Figure 5, during the execution of unit count control (step S1), the control device 180 repeatedly executes the processes of steps S105 to S190 at a predetermined sampling period.

[0073] In step S105, the control device 180 executes a process to determine whether the first to third stop conditions have been met. If the control device 180 determines that the stop conditions have been met, it sets a stop flag associated with the compression module 101 for which the stop conditions have been met. For example, if the control device 180 determines that the first stop condition has been met for the first compression module 101A, it switches the temperature abnormal stop flag Ft(1) of the first compression module 101A from the unset state (off) to the set state (on) (Ft(1)=0→Ft(1)=1). Also, for example, if the control device 180 determines that the second stop condition has been met for the second compression module 101B, it switches the current abnormal stop flag Fi(2) of the second compression module 101B from the unset state (off) to the set state (on) (Fi(2)=0→Fi(2)=1). Furthermore, for example, if the control device 180 determines that the third stop condition has been met for the third compression module 101C, it switches the maintenance stop flag Fm(3) of the third compression module 101C from the unset state (off) to the set state (on) (Fm(3)=0 → Fm(3)=1).

[0074] Once the stop determination process (step S105) is completed, the process proceeds to step S110. In step S110, the control device 180 determines whether a stop flag has been set in at least one of the multiple compression modules 101. If it is determined in step S110 that the stop flag has not been set in any of the multiple compression modules 101, the process proceeds to step S190. If it is determined in step S110 that a stop flag has been set in at least one of the multiple compression modules 101, the process proceeds to step S115.

[0075] In step S115, the control device 180 performs a stop process to stop the compression module 101 for which the stop flag has been set, and then proceeds to step S120.

[0076] In step S120, the control device 180 performs an exclusion process to exclude the compression module 101 for which the stop flag is set from the unit control, and proceeds to step S190.

[0077] In step S190, the control device 180 determines whether or not the stop switch 172b has been operated. If it is determined in step S190 that the stop switch 172b has not been operated, the process returns to step S105. If it is determined in step S190 that the stop switch 172b has been operated, the process proceeds to step S195. In step S195, the control device 180 stops all compression modules 101 and terminates the process shown in the flowchart of Figure 5.

[0078] The following will explain in detail the control of the commissioning of the compression module 101 and the return to commissioning during unit control, with reference to Figure 6. When the operation to start commissioning is performed on the operation panel 170, the control device 180 sets the commissioning mode. The process shown in Figure 6 is executed when the commissioning mode is set. As shown in Figure 6, when the commissioning mode is set, in step S130, the control device 180 displays a selection operation screen on the display unit 171a prompting the user to select a compression module 101 to be commissioned. The selection operation screen is, for example, a screen that displays the number of the compression module 101 to be commissioned (for example, 1 to 3). Each time the display switching switch 172d is operated, the number of the compression module 101 on the display unit 171a is switched. When the menu switch 172c is operated while the number representing the compression module 101 to be commissioned is displayed, the control device 180 selects the compression module 101 corresponding to the number displayed on the commissioning unit selection screen as the compression module 101 to be commissioned. Furthermore, it is not possible to perform a test run on the compression module 101 while it is not stopped.

[0079] In step S130, if the compression module 101 to be test-run is selected, the process proceeds to step S135. In step S135, the control device 180 supplies power to the motor 120 of the compression module 101 selected in step S130 using the electromagnetic switch 140, thereby executing a test run process that operates the motor 120 at a constant speed for a predetermined time tp. The predetermined time tp should be any time sufficient to check for abnormalities in the compression module 101, and is typically set to a value of a few seconds to a few minutes. In the initial setup, it is preferable to set the predetermined time tp to a few seconds and allow it to be changed using the operation panel 170. By limiting the test run time to a few seconds, further wear (deterioration) of the compression module 101 can be suppressed. Furthermore, by allowing the predetermined time tp to be changed using the operation panel 170, the accuracy of checking for abnormalities can be improved by changing the predetermined time tp to a longer time than the initial setting as needed.

[0080] In step S135, the control device 180 may stop the operating compression modules 101 for a predetermined time tp by controlling the number of units in order to suppress changes in the flow rate of the gas discharged from the compressor 10. For example, when two compression modules, the first compression module 101A and the second compression module 101B, are in operation, and a trial run of the third compression module 101C, for which a stop flag has been set, the control device 180 may start the third compression module 101C and stop the operation of either the first compression module 101A or the second compression module 101B.

[0081] Once the trial run process (step S135) is complete, the process proceeds to step S140. In step S140, the control device 180 displays the flag release selection screen on the display unit 171a. The flag release selection screen prompts the user to select, for example, whether or not to release the stop flag. Each time the display switching switch 172d is operated, the display of "y" and "n" as the selection option on the flag release selection screen switches.

[0082] In step S140, the control device 180 determines whether or not an operation to release the stop flag has been performed. In step S140, if the menu switch 172c is operated while "y" is displayed on the display unit 171a, the control device 180 determines that an operation to release the stop flag has been performed and proceeds to step S145. In step S140, if the menu switch 172c is operated while "n" is displayed on the display unit 171a, the control device 180 terminates the trial run mode without releasing the stop flag of the compression module 101 that has been trial run. Note that the method of releasing the stop flag is not limited to this.

[0083] In step S145, the control device 180 releases the stop flag setting for the compression module 101 that underwent trial operation and proceeds to step S150. In step S150, the control device 180 includes the compression module 101 whose stop flag was released in step S145 as a target for unit control and ends the trial operation mode. While the compression module 101 with the stop flag set is undergoing trial operation, the compression modules 101 without the stop flag set continue to operate under unit control. In other words, in step S150, the compression module 101 whose stop flag was released returns to unit control operation.

[0084] According to the above-described embodiment, the following effects are achieved.

[0085] (1) The compressor 10 comprises a compressor unit 100 having a compressor body 110 for compressing gas and a motor 120 for driving the compressor body 110, and a control device 180 for controlling the number of compressor units 100. The multiple compressor units 100 are connected to the same piping (main discharge piping 105). The control device 180 starts up compressor units 100 that are not subject to the number control while continuing to control the number of compressor units 100 that are subject to the number control.

[0086] With this configuration, if a predetermined compressor unit 100 (for example, the third compressor unit 100C) stops due to abnormality detection or the like, the predetermined compressor unit (for example, the third compressor unit 100C) can be started and test-driven without interfering with the multi-unit control operation by the other compressor units (for example, the first and second compressor units 100A and 100B). After confirming that it is functioning correctly, it can be incorporated into the multi-unit control operation. Since the test-driven operation of the predetermined compressor unit 100 does not interfere with the multi-unit control operation of the other compressor units 100, the operating rate of the compressor 10 can be improved.

[0087] (2) The control device 180 determines whether or not there is an abnormality in any of the compressor units 100. The control device 180 stops any compressor units 100 that it determines to have an abnormality and excludes them from the unit count control, while continuing the unit count control for any compressor units 100 that it determines to have no abnormality, and restarts any compressor units 100 that it determines to have an abnormality.

[0088] This configuration allows for the restart and trial operation of a compressor unit 100 that has been determined to be abnormal, without interfering with the unit control operation of a compressor unit 100 that has been determined to be normal. After confirming that it is functioning correctly, it can then be incorporated into the unit control operation. Therefore, a compressor unit 100 that has been determined to be abnormal due to a false detection can be quickly returned to unit control. For example, when the door to the room in which the compressor 10 is installed is opened and outside air flows into the room, the ambient temperature T2 may drop rapidly. In this case, the rate of decrease in the temperature T1(j) of the compressor body 110 is smaller than the rate of decrease in the ambient temperature T2. That is, the absolute value of the rate of change of the temperature T1(j) of the compressor body 110 is smaller than the absolute value of the rate of change of the ambient temperature T2. As a result, the temperature difference ΔT may exceed the temperature threshold T0, and a temperature abnormality may be detected.

[0089] Thus, even if there is no leakage in the tip seals 111d and 112d of the compressor body 110, a temperature anomaly may be falsely detected. If the entire compressor 10 is stopped in such a case, the operating rate of the compressor 10 will decrease. Therefore, the user performs a test run to determine whether the temperature anomaly is a false detection. The user determines whether the temperature anomaly is a false detection by measuring the temperature of the compressor body 110 with a temporary thermometer or by displaying the detected value of the permanent temperature sensor 132 on the display unit 171a.

[0090] If the user determines that the temperature anomaly was a false detection, they can deactivate the stop flag (temperature anomaly stop flag) by performing a deactivation operation. This allows the compressor unit 100 that was stopped due to the false detection to quickly return to unit control. Furthermore, while a series of processes such as stopping a specific compressor unit 100 due to a false detection, performing a trial run on that compressor unit 100, and returning that compressor unit 100 to unit control are being executed, the other compressor units 100 continue to operate under unit control. Therefore, the decrease in the operating rate of the compressor 10 can be minimized. In other words, according to this embodiment, the decrease in the operating rate of the compressor 10 can be suppressed compared to the case where the entire compressor 10 is stopped before the trial run.

[0091] (3) The current abnormality may be caused by compressed gas leakage due to deterioration of the tip seals 111d and 112d of the compressor body 110, contact between overlapping sections due to deformation of the overlapping sections 111b and 112b, and deterioration of the bearings 124A and 124B. Therefore, the user will perform a test run to confirm the cause of the current abnormality. The user will listen for any abnormal noises caused by contact between overlapping sections or abnormal noises from the bearings 124A and 124B. The user will also measure the temperature of the compressor body 110 with a temporary thermometer or have the detection value of the permanent temperature sensor 132 displayed on the display unit 171a. Based on the sound during the test run of the compressor unit 100 and the temperature of the compressor body 110, the user will be able to identify the cause of the current abnormality. After that, the user will stop the compressor 10 and perform maintenance work to eliminate the cause of the current abnormality. Thus, in this embodiment, while a trial run is being performed to identify the cause of a current abnormality in a predetermined compressor unit 100, the control of the number of other compressor units 100 can be continued, thereby improving the operating rate of the compressor 10.

[0092] (4) If the control device 180 determines that there is an abnormality in the compressor unit 100, it sets a stop flag on the compressor unit 100 that has been determined to be abnormal. The control device 180 continues to control the number of compressor units 100 for which the stop flag has not been set, and executes an exclusion process to stop the compressor unit 100 for which the stop flag has been set and exclude it from the target of the number of compressor units. The control device 180 continues to control the number of compressor units 100 for which the stop flag has not been set, and executes a trial run process to restart the compressor unit 100 for which the stop flag has been set. If the trial run process has not been completed after the exclusion process has been executed, it is not possible to remove the stop flag setting. If the trial run process has been completed after the exclusion process has been executed, it is possible to remove the stop flag setting.

[0093] If it were possible to release the stop flag setting without completing the commissioning process of the specified compressor unit 100, the following problems could arise. In fact, if a temperature anomaly occurs due to leakage in the tip seals 111d and 112d and the compressor unit 100 stops, there is a risk that the user may mistakenly release the stop flag setting. In this case, it may lead to further deterioration of the tip seals 111d and 112d. In contrast, in this embodiment, the stop flag setting cannot be released unless the commissioning process is completed. Therefore, the above problems do not occur. In other words, the user can perform a commissioning process to determine whether the temperature anomaly is a false detection or not, and if the temperature anomaly is not a false detection, the user can stop the compressor 10 and take appropriate measures such as replacing the tip seals 111d and 112d of the compressor unit 100.

[0094] (5) When the control device 180 is performing number control on the compressor units 100 that are subject to number control, if the stop flag setting of a compressor unit 100 that is not subject to number control is released, the control device 180 continues number control and includes the compressor unit 100 whose stop flag setting has been released as a target of number control. With this configuration, the compressor unit 100 that has undergone trial operation can be returned to number control without stopping the compressor 10. For this reason, according to this embodiment, the operating rate of the compressor 10 can be improved compared to the case in which the compressor 10 is stopped when returning the compressor unit 100 to number control.

[0095] (6) The compressor 10 is equipped with an electromagnetic switch 140 that switches between supplying and cutting off power to the motor 120. The control device 180 supplies power to the motor 120 via the electromagnetic switch 140, thereby stopping the compressor unit 100 that is not subject to the unit control at a constant speed for a predetermined time tp. With this configuration, the operating time of the trial run is limited to a predetermined time tp. In other words, it is prevented that the trial run will be performed continuously beyond the predetermined time tp. Therefore, it is possible to prevent damage to the compression module 101 due to the trial run being performed for a long period of time.

[0096] <Modified form of the first embodiment> In the first embodiment, an example was described in which there are three compressor units 100, and one compressor unit 100 is not subject to unit count control, and a trial run is performed on that compressor unit 100, and after the stop flag is released, the unit count control is returned. However, the present invention is not limited to this. For example, the present invention may be applied to a compressor 10 equipped with four or more compressor units 100, and to a compressor 10 equipped with only two compressor units 100. However, in the case of a compressor 10 equipped with only two compressor units 100, when one of the two compressor units 100 is stopped due to the stop flag, only one compressor unit 100 remains that is normally operational. In this case, the remaining compressor unit 100 is not additionally started by the processing in steps S70 and S80 in Figure 4, but the flow of the unit count control processing shown in Figure 4 is the same. In other words, in a compressor 100 equipped with two or more compressor units 100, the control device 180 performs the number control shown in Figure 4, regardless of the number of compressor units 100 that are stopped.

[0097] Furthermore, if there are multiple compressor units 100 that are not subject to the unit count control, a test run may be performed on the compressor units 100 that are not subject to the unit count control, and after the stop flag is released, the unit count control may be restored. In the case of multiple compressor units 100 that are not subject to the unit count control, it is preferable to perform a test run on each unit one by one. If multiple compressor units 100 are test-run simultaneously, it may be difficult to check for any abnormalities.

[0098] Figure 7 is similar to Figure 6 and is a flowchart showing the control content when the trial operation mode is set by the control device 180 according to a modified example of the first embodiment. In the flowchart of Figure 7, the process of step S160 is added after the process of step S150 in the flowchart of Figure 6. As shown in Figure 7, in step S150, once the process of including the compression module 101 with the stop flag released as a target for number control is completed, the process proceeds to step S160.

[0099] In step S160, the control device 180 determines whether the termination conditions for the trial run mode have been met. If there is a stop flag set on any of the multiple compression modules 101, the control device 180 determines that the termination conditions for the trial run mode have not been met and returns to step S130. If there is no stop flag set on any of the multiple compression modules 101, the control device 180 determines that the termination conditions for the trial run mode have been met and terminates the process shown in the flowchart of Figure 7. In step S130, the control device 180 selects only one compression module 101 with a stop flag set and proceeds to step S135.

[0100] Thus, in this modified configuration, if there are multiple compressor units 100 that are not subject to the unit count control, the control device 180 drives each of the multiple compressor units 100 that are not subject to the unit count control one by one. Therefore, if there are multiple compressor units 100 with a stop flag set, the user selects which compressor units 100 to test run one by one and performs the test run on each unit individually. This allows, for example, the presence or absence of abnormalities in the compressor units 100 to be appropriately confirmed based on the sound of the compressor unit 100 during the test run.

[0101] <Second Embodiment> The compressor 20 according to the second embodiment of the present invention will be described with reference to Figures 8 and 9. Components identical or equivalent to those described in the first embodiment will be given the same reference numerals, and the differences will be primarily explained. Figure 8 is similar to Figure 1 and shows the configuration of the compressor 20 according to the second embodiment.

[0102] In the first embodiment, the compressor 10 was configured such that the motor 120 rotated at a constant speed by an electromagnetic switch 140 (see Figure 1). In contrast, the compressor 20 according to the second embodiment is configured such that the rotational speed of the motor 120 is controlled by an inverter 240, as shown in Figure 8. The compressor 20 according to the second embodiment will be described in detail below.

[0103] The compressor 20 according to the second embodiment has substantially the same configuration as that of the first embodiment, but instead of the electromagnetic switch 140 described in the first embodiment, an inverter 240 is provided to supply power from the power source to the motor 120. Note that the inverter 240A of the first compression module 101A, the inverter 240B of the second compression module 101B, and the inverter 240C of the third compression module 101C have the same configuration.

[0104] The control device 280 controls the rotational speed of the motor 120 using the inverter 240 so that the discharge pressure (i.e., the pressure detected by the pressure sensor 131), which changes according to the amount of compressed gas used, becomes a predetermined target pressure value. In this embodiment, the control device 280 controls the rotational speed of the motor 120 by converting the current frequency of the commercial power supply (e.g., 60Hz) to a target current frequency based on the detection result of the pressure sensor 131 and supplying it to the motor 120.

[0105] The inverter 240 includes a plurality of switching elements, a voltage sensor 235, and a current sensor 236. The inverter 240 has a well-known configuration comprising a converter circuit, an inverter circuit, and a smoothing capacitor. The inverter circuit converts the DC current supplied from the converter circuit into AC current using switching elements. The voltage sensor 235 detects the DC voltage between a pair of power lines (DC buses) connecting the converter circuit and the inverter circuit, and outputs a voltage signal representing the detection result to the control device 280. The current sensor 236 is provided on a conductive member connecting the inverter circuit and the armature windings of each phase of the motor (three-phase AC motor) 120, and detects the current supplied to the motor 120, and outputs a current signal representing the detection result to the control device 280.

[0106] In the first embodiment, the compressor unit 100 was operated at a constant speed, and the discharge flow rate was kept constant regardless of the amount of compressed gas used. In contrast, in the second embodiment, the compressor can be operated in a capacity control manner, where the motor rotation speed is controlled by the inverter 240 according to the amount of compressed gas used to adjust the discharge flow rate (output), or in a fixed control manner, where the discharge flow rate (output) is kept constant regardless of the amount of compressed gas used. For example, in multi-unit control operation, when the amount of gas used does not fluctuate much, the discharge pressure (tank pressure) may be kept near the lower limit pressure by controlling the rotation speed of the motor 120 without starting or stopping the compressor unit 100. This makes it possible to avoid operation in the high-pressure range and thus reduce power consumption.

[0107] The control device 280 determines whether the following first to fifth stop conditions are met. If any of the first to fifth stop conditions are met, the control device 280 sets a stop flag and stops the compression module 101 for which the stop flag has been set. (First stop condition) The temperature difference ΔT, which is the difference between the temperature T1 of the compressor body 110 and the ambient temperature T2 of the compressor 20, is greater than or equal to the temperature threshold T0. In other words, a temperature anomaly has occurred. (Second stop condition) The current I detected by the current sensor 236 is greater than or equal to the current threshold I0. In other words, a current abnormality has occurred. (Third stop condition) Cumulative operating time has reached the maintenance time. (Fourth stop condition) The voltage V detected by the voltage sensor 235 is above the high voltage threshold VH. In other words, a high voltage anomaly has occurred. (Fifth stop condition) The voltage V detected by the voltage sensor 235 is less than the low voltage threshold VL. In other words, a low voltage anomaly has occurred.

[0108] The first and third stop conditions in the second embodiment are the same as those in the first embodiment, so their explanation is omitted. The second stop condition in the second embodiment is the same in that it is triggered by the occurrence of a current abnormality, but in the second embodiment, overcurrent is detected based on the current I detected by the current sensor 236 of the inverter 240. The causes of temperature abnormalities and current abnormalities are the same as in the first embodiment, so their explanation is omitted.

[0109] The process by which the control device 280 determines whether the fourth stop condition is met is equivalent to the process of determining whether there is a high voltage anomaly. When the check valve 151 of a predetermined compression module 101 deteriorates over time, compressed gas may flow back into the compressor body 110 of the predetermined compression module 101 from the main discharge piping 105 side. When the predetermined compression module 101 is stopped, if compressed gas flows back into the compressor body 110 of that compression module 101, the compressor body 110 rotates, and the motor 120 rotates. As a result, the motor 120 generates electricity, and the voltage V detected by the voltage sensor 235 rises above normal levels. In other words, when the check valve 151 deteriorates and backflow into the compressor body 110 occurs, the control device 280 detects a high voltage anomaly.

[0110] The process by which the control device 280 determines whether the fifth stop condition is met is equivalent to the process of determining whether there is a low voltage anomaly. When the check valve 151 of a predetermined compression module 101 deteriorates over time and compressed gas leaks, a step loss may occur when driving the compressor unit 100. As a result, the voltage V detected by the voltage sensor 235 decreases compared to normal. In other words, when the check valve 151 deteriorates and the compressor unit 100 loses step, the control device 280 detects a low voltage anomaly.

[0111] If the first stop condition is met, the control device 280 sets the temperature abnormal stop flag Ft(j) as the stop flag (Ft(j)=1). If the second stop condition is met, the control device 280 sets the current abnormal stop flag Fi(j) as the stop flag (Fi(j)=1). If the third stop condition is met, the control device 280 sets the maintenance stop flag Fm(j) as the stop flag (Fm(j)=1). If the fourth stop condition is met, the control device 280 sets the high voltage abnormal stop flag Fvh(j) as the stop flag (vh(j)=1). If the fifth stop condition is met, the control device 280 sets the low voltage abnormal stop flag Fvl(j) as the stop flag (Fvl(j)=1).

[0112] The control device 280 determines whether the current I(j) detected by the current sensor 236 is greater than or equal to the current threshold I0. The current threshold I0 is stored in advance in the non-volatile memory 182. If the current I(j) is less than the current threshold I0, the control device 280 determines that the second stop condition is not met and maintains the current abnormal stop flag Fi(j) in an unset state (Fi(j)=0). If the current I(j) is greater than or equal to the current threshold I0, the control device 280 determines that the second stop condition is met and sets the current abnormal stop flag Fi(j) (Fi(j)=1). The current abnormal stop flag Fi(j) is a stop flag that indicates that a current abnormality has been detected in the compressor unit 100 of the compression module 101, and is set in association with the compression module 101 for which the second stop condition has been determined to be met.

[0113] The control device 280 determines whether the voltage V(j) detected by the voltage sensor 235 is equal to or greater than the high voltage threshold VH. The high voltage threshold VH is stored in advance in the non-volatile memory 182. If the voltage V(j) is less than the high voltage threshold VH, the control device 280 determines that the fourth stop condition is not met and maintains the high voltage abnormal stop flag Fvh(j) in an unset state (Fvh(j)=0). If the voltage V(j) is equal to or greater than the high voltage threshold VH, the control device 280 determines that the fourth stop condition is met and sets the high voltage abnormal stop flag Fvh(j) (Fvh(j)=1). The high voltage abnormal stop flag Fvh(j) is a stop flag that indicates that a high voltage abnormality has been detected in the compressor unit 100 of the compression module 101, and is set in association with the compression module 101 for which the fourth stop condition has been determined to be met.

[0114] The control device 280 determines whether the voltage V(j) detected by the voltage sensor 235 is less than the low voltage threshold VL. The low voltage threshold VL is a threshold lower than the high voltage threshold VH and is stored in advance in the non-volatile memory 182. If the voltage V(j) is greater than or equal to the low voltage threshold VL, the control device 280 determines that the fifth stop condition is not met and maintains the low voltage abnormal stop flag Fvl(j) in an unset state (Fvl(j)=0). If the voltage V(j) is less than the low voltage threshold VL, the control device 280 determines that the fourth stop condition is met and sets the low voltage abnormal stop flag Fvl(j) (Fvl(j)=1). The low voltage abnormal stop flag Fvl(j) is a stop flag that indicates that a low voltage abnormality has been detected in the compressor unit 100 of the compression module 101, and is set in association with the compression module 101 for which the fifth stop condition has been determined to be met.

[0115] The control device 280 according to this second embodiment performs the same processing as shown in Figures 5 and 6 described in the first embodiment. In this second embodiment, in step S105 shown in Figure 5, the control device 280 performs a process to determine whether the first to fifth stop conditions have been met. If the control device 280 determines that the stop conditions have been met, it sets a stop flag in association with the compression module 101 for which the stop conditions have been met.

[0116] In step S135 shown in Figure 6, the control device 280 performs a trial run process in which the compression module 101 selected in step S130 is operated for a predetermined time tp. In this second embodiment, the control device 280 rotates the motor 120 at a minimum speed Ntmin during the trial run process. The minimum speed Ntmin is the lowest value within the speed control range of the motor 120. The minimum speed Ntmin can also be said to be the lowest speed at which the compressor unit 100 can be rotated stably.

[0117] Thus, the control device 280 according to the second embodiment operates the motor 120 of the compressor unit 100 that is not subject to unit control at the lowest speed for a predetermined time and then stops it. If the overlapping parts 111b and 112b come into contact and an abnormal current in the compressor unit 100 is detected, causing the compressor unit 100 to stop, then performing a test run at the highest speed within the speed control range of the motor 120 may damage the overlapping parts 111b and 112b. In contrast, in this second embodiment, since the motor 120 is operated at the lowest speed, damage to the compression module 101 can be prevented. In other words, according to this second embodiment, it is possible to determine whether the motor 120 is functioning normally by test running it while preventing damage to the compression module 101.

[0118] <Modified form of the second embodiment> The control device 280 may gradually increase the rotational speed of the motor 120 of the compressor unit 100 that is not subject to the unit count control from the minimum speed Ntmin to a predetermined speed (for example, the maximum speed Ntmax) as time progresses. The non-volatile memory 182 stores a target rotational speed table (see Figure 9), which is a data table that defines the relationship between the elapsed time te of the trial run and the target rotational speed Nt. As shown in Figure 9, from the elapsed time te of the trial run from 0 to te1, the target rotational speed Nt is the minimum speed Ntmin. After the elapsed time te of the trial run exceeds te1, the longer the elapsed time te of the trial run becomes, the greater the target rotational speed Nt becomes, and when the elapsed time te reaches te2, the target rotational speed Nt becomes the maximum speed Ntmax. After the elapsed time te exceeds te2, the target rotational speed Nt is maintained at the maximum speed Ntmax, and when the elapsed time te reaches a predetermined time tp, the target rotational speed Nt becomes 0.

[0119] When the control device 280 starts the trial run process (step S135 in Figure 6), it begins measuring the elapsed time te during the trial run. The control device 280 calculates the target rotational speed Nt according to the elapsed time te by referring to the target rotational speed table shown in Figure 9. The control device 280 outputs a control signal to the inverter 240 to rotate the motor 120 at the target rotational speed Nt.

[0120] As a result, the rotational speed of the motor 120 gradually increases over time. With this modified example, it is possible to check for any specific abnormalities corresponding to the rotational speed.

[0121] For example, if the tip seals 111d and 112d are deteriorated, even if the motor 120 is rotating at a low speed, the high-temperature compressed gas will leak through the tip seals 111d and 112d and be further compressed, causing the temperature of the compressor body 110 to rise. Furthermore, when a test run is performed at a low speed, the rotation speed of the cooling fan 130 is also low, so the temperature of the compressor body 110 is likely to rise. Therefore, by measuring the temperature of the compressor body 110, the user can check whether or not the tip seals 111d and 112d are deteriorated when a test run is performed at a low speed.

[0122] Furthermore, increasing the rotational speed of the motor 120 increases the amount of deformation of the overlapping sections 111b and 112b due to centrifugal force. Therefore, the user can check whether or not the overlapping sections 111b and 112b are making contact by listening to the sound generated from the compressor unit 100 or by measuring the motor drive current while the rotational speed of the motor 120 is gradually increasing.

[0123] Thus, in this modified example, it is possible to check for the presence or absence of specific abnormalities depending on the rotation speed, making it easy to identify the cause of the abnormality.

[0124] <Third Embodiment> A compressor 30 according to the third embodiment of the present invention will be described with reference to Figures 10 and 11. Components identical or equivalent to those described in the second embodiment will be given the same reference numerals, and the differences will be primarily explained. Figure 10 is similar to Figure 8 and shows the configuration of the compressor 30 according to the third embodiment of the present invention.

[0125] As shown in Figure 10, the compressor 30 is equipped with a microphone 337 as a sound acquisition device that acquires sound generated from the compressor unit 100. A microphone 337 is provided for each compression module 101, and it converts the acquired sound into an electrical signal (hereinafter referred to as sound data) and outputs it to the control device 380 via a signal line (not shown). Based on the sound generated from the compressor unit 100 on which the trial run process has been performed, the control device 380 determines whether or not there is an abnormality in the compressor unit 100 on which the trial run process has been performed, and outputs the determination result.

[0126] Figure 11 is similar to Figure 6 and is a flowchart showing the control content when the trial operation mode is set by the control device 380 according to the third embodiment. In the flowchart of Figure 11, steps S335, S336, and S337 are executed instead of step S135 in the flowchart of Figure 6.

[0127] As shown in Figure 11, in step S130, when the control device 380 according to the third embodiment selects the compression module 101 to be test-driven, the process proceeds to step S335. In step S335, the control device 380 performs a test-driven operation, running the motor 120 of the compression module 101 selected in step S130 for a predetermined time tp. Furthermore, during the test-driven operation, the control device 380 acquires sound data from the microphone 337 and stores it in the non-volatile memory 182.

[0128] Once the trial run process (step S335) is completed, the process proceeds to step S336. In step S336, the control device 380 diagnoses whether or not there is an abnormality in the compressor unit 100 that has undergone the trial run process. In this automatic diagnostic process (step S336), the control device 380 compares the sound data acquired in step S335 and stored in the non-volatile memory 182 with reference sound data that has been previously stored in the non-volatile memory 182. The reference sound data is, for example, sound data measured at the time of shipment of the compressor 30. Based on the comparison result between the acquired sound data and the reference sound data, the control device 380 determines whether or not there is an abnormality in the compressor unit 100. For example, if the difference between the frequency of the acquired sound data and the frequency of the reference sound data is within a predetermined allowable range, the control device 380 determines that there is no abnormality in the compressor unit 100. If the difference between the frequency of the acquired sound data and the frequency of the reference sound data is outside the predetermined allowable range, the control device 380 determines that there is an abnormality in the compressor unit 100. Furthermore, the control device 380 may determine that there is no abnormality in the compressor unit 100 if the difference (amplitude difference) between the maximum amplitude (magnitude) of the acquired sound data and the maximum amplitude (magnitude) of the reference sound data is within a predetermined allowable range, and may determine that there is an abnormality in the compressor unit 100 if the amplitude difference is outside the predetermined allowable range.

[0129] Once the automatic diagnostic process (step S336) is completed, the process proceeds to step S337. In step S337, the control device 380 displays the result of the determination in step S337 (diagnosis result) on the display unit 171a and proceeds to step S140. Note that the diagnostic result output process (step S337) can also be performed by outputting the diagnostic result using a sound output device such as a speaker, instead of outputting the diagnostic result using the display unit 171a.

[0130] According to this third embodiment, when performing the trial run process, it is possible to automatically diagnose whether or not there is an abnormality in the compressor unit 100. Therefore, the user can easily determine whether or not it is OK to release the stop flag.

[0131] <Modified form of the third embodiment> In the third embodiment, an example was described in which the device determines whether or not there is an abnormality in the compressor unit 100 that has undergone a trial run based on the sound generated from the compressor unit 100 that has undergone a trial run and acquired by the microphone 337, but the present invention is not limited thereto. The control device 380 may also determine whether or not there is an abnormality in the compressor unit 100 that has undergone a trial run based on the current supplied to the motor 120 of the compressor unit 100 that has undergone a trial run, that is, the current detected by the current sensor 236. Alternatively, the control device 380 may also determine whether or not there is an abnormality in the compressor unit 100 that has undergone a trial run based on the temperature of the compressor body 110 of the compressor unit 100 that has undergone a trial run, that is, the temperature detected by the temperature sensor 132.

[0132] In other words, the control device 380 only needs to be configured to determine whether or not there is an abnormality in the compressor unit 100 during the trial run process, based on at least one of the sound generated from the compressor unit 100 during the trial run process, the current supplied to the motor 120, and the temperature of the compressor body 110, and to output the result of that determination. With this configuration, it is possible to automatically diagnose whether or not there is an abnormality in the compressor unit 100 when the trial run process is performed. Therefore, the user can easily determine whether or not it is OK to release the stop flag.

[0133] Furthermore, if an automatic diagnosis of the compressor unit 100 after the trial run process has been performed determines that there is no abnormality in the compressor unit 100, the control device 380 may automatically release the stop flag. In this case, since there is no need for the user to release the stop flag, the time from trial run to return to unit control can be shortened.

[0134] The following modifications are also within the scope of the present invention, and it is possible to combine the configurations shown in the modifications with the configurations described in the embodiments described above, or to combine the configurations described in the different embodiments described above, or to combine the configurations described in the following different modifications.

[0135] <Example 1> The first and fifth stop conditions may be met due to false detection of temperature anomalies and low voltage anomalies. False detection of temperature anomalies occurs, for example, when the temperature difference ΔT exceeds the temperature threshold T0 due to the opening and closing of doors in the rooms where compressors 10, 20, and 30 are installed, or the operation of an air conditioner. False detection of low voltage anomalies occurs, for example, when motor 120 is subjected to control involving large speed changes, and the rotation of the rotor 122 cannot properly follow the rotational magnetic field generated by the current supplied from the inverter 240 to the stator 121, causing it to lose synchronism and the motor drive voltage V falls below the low voltage threshold VL. In contrast, the second, third, and fourth stop conditions will not be met due to false detection. Therefore, control devices 180, 280, and 380 may decide whether or not to execute the trial run process according to the stop flag.

[0136] In this modified example, the control devices 180, 280, and 380 set a stop flag corresponding to any of the predetermined stop conditions when one of several stop conditions is met, and determine whether or not to execute the trial run process based on the set stop flag.

[0137] The following describes an example of a modification of the second embodiment. As shown in Figure 12, the non-volatile memory 182 of the control device 280 stores the relationship between the stop flag and whether or not the trial run process can be executed. As shown in Figure 12, when the temperature abnormality stop flag or the low voltage abnormality flag is set, the control device 280 determines that the trial run process can be executed and displays this fact on the display unit 171a. When the temperature abnormality stop flag or the low voltage abnormality flag is set, and the operation to start the trial run is performed on the operation panel 170, the control device 280 sets the trial run mode and executes the process shown in the flowchart of Figure 6.

[0138] On the other hand, if the high-voltage abnormal stop flag is set, the control device 280 determines that it is impossible to perform the trial run process and displays this fact on the display unit 171a. For example, the control device 280 displays a message such as "A high-voltage abnormality has occurred. Please replace the check valve 151," or an error code corresponding to that message, on the display unit 171a. If the operation to start a trial run is performed on the operation panel 170 while the high-voltage abnormal stop flag is set, the control device 280 displays on the display unit 171a that it is impossible to perform the trial run process and does not set the trial run mode.

[0139] This prevents a test run from being performed on the compression module 101 in which a high-voltage anomaly has been detected before the check valve 151 is replaced. The user stops the entire compressor 20, including the compression module 101 in which no anomalies have been detected, replaces the check valve 151 of the compression module 101 in which an anomaly has been detected, and then performs a reset operation using the control panel 170. As a result, the control device 280 clears the high-voltage anomaly stop flag for the compression module 101. The control device 280 also clears the high-voltage anomaly stop flag when the power to the compressor 10 is turned off.

[0140] Similarly, if the current abnormality stop flag is set, the control device 280 determines that the trial run process cannot be performed and displays this fact on the display unit 171a. For example, the control device 280 displays a message such as "A current abnormality has occurred. Repair or replace the compressor unit," or an error code corresponding to that message, on the display unit 171a. If the operation to start a trial run is performed on the operation panel 170 while the current abnormality stop flag is set, the control device 280 displays on the display unit 171a that the trial run process cannot be performed and does not set the trial run mode.

[0141] This prevents a test run from being performed on the compression module 101 in which a current anomaly has been detected before the compressor unit 100 has been repaired or replaced. The user stops the entire compressor 20, including the compression module 101 in which no anomalies have been detected, repairs or replaces the compressor unit 100 of the compression module 101 in which an anomaly has been detected, and then performs a reset operation using the control panel 170. As a result, the control device 280 clears the current anomaly stop flag for the compression module 101. The control device 280 also clears the current anomaly stop flag when the power to the compressor 10 is turned off.

[0142] Thus, according to this modified configuration, the control device 280 determines whether or not to perform a trial run based on the type of stop flag. Therefore, if a predetermined stop flag (for example, a high-voltage abnormality stop flag or a current abnormality flag) is set, the trial run is prohibited, thus preventing damage to the compression module 101 due to the trial run.

[0143] <Modification 2> In step S135 of Figure 6, an example was described in which the control devices 180 and 280 rotate the motor 120 of the compression module 101 for a predetermined time tp and then automatically stop the motor 120, but the present invention is not limited to this. The control device 180 may terminate the trial run process (step S135 in Figure 6) in response to user operation.

[0144] For example, in step S135 of Figure 6, when the motor 120 of the compression module 101 is rotating, if the stop switch 172b on the operation panel 170 is operated, the control device 180 stops the motor 120 before a predetermined time tp has elapsed. With this configuration, a trial run can be performed that is in line with the state of the compressor unit 100.

[0145] <Variation 3> In the above embodiment, a configuration was described in which the shaft 123 of the motor 120 is directly attached to the orbiting scroll 112 and the power of the motor 120 is directly transmitted to the orbiting scroll 112. However, the present invention is not limited to this. A pulley may be provided on both the shaft of the motor 120 and the shaft of the orbiting scroll 112, and a belt that transmits the power generated by the motor 120 to the orbiting scroll 112 may be attached to the pulley of the motor 120 and the pulley of the orbiting scroll 112. In this configuration, if the belt wears or stretches due to aging, the force required to drive the compressor body 110 increases, and the motor drive current rises above normal. In other words, if the belt deteriorates, the control device 180 will detect a current abnormality.

[0146] <Modification 4> The stop conditions are not limited to those described in the above embodiments. For example, in the second embodiment, the control device 280 may set a stop flag when an abnormality is detected in the inverter 240, indicating that the stop conditions have been met.

[0147] <Modification 5> In the first embodiment, an example of an abnormality detected by the control device 180 was described as one caused by the aging deterioration of the tip seals 111d, 112d, bearings 124A, 124B, and lapping sections 111b, 112b, but the present invention is not limited to this. For example, the magnets used in the motor 120 gradually demagnetize due to aging deterioration. For this reason, the control device 180 may be configured to detect current abnormalities caused by the aging deterioration of the magnets.

[0148] <Variation 6> In the above embodiments, examples were described in which compressors 10, 20, and 30 have scroll-type compressor units 100, but the present invention is not limited thereto. Compressors 10, 20, and 30 may consist of multiple well-known screw-type, reciprocating (piston-type), and turbo-type compressor units. The present invention may also be applied to compressors that consist of multiple compressor units of different types. For example, the present invention may be applied to a compressor that includes a control device for controlling the number of operating compressor units, totaling four units: two scroll-type compressor units and two reciprocating compressor units.

[0149] The embodiments described above are merely examples to aid in understanding the concept of the present invention and are not intended to limit the scope of the invention. The embodiments may include additions, deletions, or substitutions of various components without departing from the spirit of the invention.

[0150] The various functional units described in each of the above embodiments may be implemented using circuits. The circuits may be dedicated circuits for implementing specific functions, or they may be general-purpose circuits such as processors.

[0151] At least a portion of the processing in each of the above embodiments can also be implemented using a general-purpose computer as the basic hardware. The program that implements the above processing may be provided stored on a computer-readable recording medium. The program is stored on the recording medium as an installable file or an executable file. The recording medium may be a magnetic disk, an optical disk (CD-ROM, CD-R, DVD, etc.), a magneto-optical disk (MO, etc.), or a semiconductor memory. Any recording medium that can store a program and is readable by a computer may be used. Alternatively, the program that implements the above processing may be stored on a computer (server) connected to a network such as the Internet, and downloaded to a computer (client) via the network. [Explanation of Symbols]

[0152] 10, 20, 30… Compressor, 100… Compressor unit, 101… Compression module, 105… Main discharge piping (piping), 110… Compressor body, 111b, 112b… Lapping section, 111d, 112d… Tip seal (sealing member), 120… Motor, 124A, 124B… Bearing, 131… Pressure sensor, 132… Temperature sensor, 133… Ambient temperature sensor, 140… Electromagnetic switch, 151… Check valve, 170… Operation panel, 171a, 171b… Display unit, 1 72a...Operation switch (operation switch), 172b...Stop switch (operation switch), 172c...Menu switch (operation switch), 172d...Display switching switch (operation switch), 180...Control device, 181...Processor, 182...Non-volatile memory, 183...Volatile memory, 190...Communication device, 235...Voltage sensor, 236...Current sensor, 240...Inverter, 280...Control device, 337...Microphone (sound acquisition device), 380...Control device

Claims

1. The system comprises multiple compressor units, each having a compressor body for compressing a gas and a motor for driving the compressor body. Piping for connecting multiple compressor units, A control device for controlling multiple compressor units, An operation panel or external information terminal for inputting commands to the control device, A compressor comprising a housing that houses a plurality of the compressor units, the control device, and the piping, and has the operation panel on its surface, The control device is Of the multiple compressor units, the compressor unit that has met the abnormal stop conditions is stopped from operating. While continuing the number-control operation of the other compressor units, a test run is performed on the compressor unit that has met the abnormal stop conditions, and after the test run is completed, the stopped compressor unit is restarted and the number-control operation is resumed. The aforementioned trial run is an operation that limits the operating time or rotational speed. The process of restarting the compressor unit, which has been stopped after the aforementioned trial run, is performed by the control device after a command indicating that there is no abnormality has been input from the operation panel or the external information terminal.

2. The system comprises multiple compressor units, each having a compressor body for compressing a gas and a motor for driving the compressor body. Piping for connecting multiple compressor units, A control device for controlling multiple compressor units, An operation panel or external information terminal for inputting commands to the control device, A compressor comprising a housing that houses a plurality of the compressor units, the control device, and the piping, and has the operation panel on its surface, The control device is Of the multiple compressor units, the compressor unit that has met the abnormal stop conditions is stopped from operating. While continuing the number-control operation of the other compressor units, a test run is performed on the compressor unit that has met the abnormal stop conditions, and after the test run is completed, the stopped compressor unit is restarted and the number-control operation is resumed. The aforementioned trial run involves gradually increasing the rotational speed. The process of restarting the compressor unit, which has been stopped after the aforementioned trial run, is performed by the control device after a command indicating that there is no abnormality has been input from the operation panel or the external information terminal.

3. In the compressor according to Claim 1, The aforementioned trial run is a compressor operation that limits both the operating time and the rotational speed.

4. In the compressor according to Claim 1, The aforementioned trial run is a compressor operation in which the operating time is limited and the rotational speed is gradually increased.

5. In the compressor according to claim 1 or claim 2, The aforementioned trial run is initiated after the control device receives a command from the operation panel or the external information terminal.

6. In the compressor according to claim 1 or claim 2, The control device is A compressor in which, if the aforementioned trial run has not been completed, the compressor unit that has met the aforementioned abnormal stop conditions cannot be returned to the aforementioned unit control operation.

7. In the compressor according to claim 1 or claim 2, The control device is A compressor that determines whether or not the aforementioned abnormal shutdown conditions have been met based on one of the following: current, voltage, temperature, or cumulative operating time.

8. In the compressor according to claim 1 or claim 2, The control device is A compressor in which, if there are two or more compressor units that satisfy the aforementioned abnormal stop conditions, the aforementioned test run is performed on each unit individually.

9. In the compressor according to claim 1 or claim 4, The control device is a compressor that sets the operating time for the trial run based on trial run time information input from the operation panel or the external information terminal.

10. In the compressor according to claim 8, The control device determines which compressor unit will perform a trial run based on a selection command input from the operation panel or the external information terminal.

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