A multi-mode operation method of screw and reciprocating compressor cooperation

Abstract

A multi-mode operation method for the coordinated operation of screw compressors and reciprocating compressors relates to the field of compressor unit control technology. The multi-mode operation includes screw compressor standalone operation mode, reciprocating compressor standalone operation mode, screw compressor and reciprocating compressor coordinated operation mode, screw compressor and reciprocating compressor coordinated gas supply operation mode, and over-condition operation mode. The unit is equipped with a wireless remote transmission module, and the host computer is connected to a cloud-based management platform, supporting real-time access from multiple terminals to achieve remote monitoring and control. Based on real-time perception and big data analysis of multi-source operating parameters, this invention innovatively constructs a full-process intelligent control architecture of "operating condition monitoring - mode matching - precise control - remote coordination", realizing intelligent switching between multiple modes such as screw compressor standalone operation, reciprocating compressor standalone operation, screw compressor and reciprocating compressor coordinated operation, screw compressor and reciprocating compressor coordinated gas supply operation, and over-condition operation.

Description

Technical Field

[0001] This invention relates to the field of compressor unit control technology, specifically to a multi-mode operation method for the coordinated operation of a screw compressor and a reciprocating compressor. Background Technology

[0002] Screw compressors are characterized by their simple structure, stable operation, and continuous discharge, making them suitable for low-to-medium pressure, low-flow operation scenarios. Reciprocating compressors, on the other hand, offer advantages such as a wide pressure range and high compression ratio, making them more suitable for high-pressure, high-flow operating conditions. In industrial settings such as coal mines and oil and gas field extraction, where there are extremely large pressure differences between the inlet and outlet, and large-volume gas lift and transportation operations, a single type of compressor often cannot handle all these conditions, leading to energy waste or low operating efficiency.

[0003] In existing technologies, screw compressors and reciprocating compressors are mostly operated and controlled independently, lacking an effective coordination mechanism. They cannot achieve automatic switching and linkage control according to changes in operating conditions. At the same time, remote control capabilities are insufficient, requiring on-site operation by staff, which not only increases labor costs but also makes it impossible to respond to changes in operating conditions and equipment failures in a timely manner, seriously affecting production continuity and operational safety. Summary of the Invention

[0004] To address the shortcomings of the existing technologies, the present invention aims to provide a multi-mode operation method for the coordinated operation of screw compressors and reciprocating compressors, which can solve the technical problems of delayed response, weak dynamic adaptability to operating conditions, and lack of remote closed-loop control system in the existing technologies.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A multi-mode operation method for the coordinated operation of a screw compressor and a reciprocating compressor, wherein the multi-mode includes a screw compressor operating mode alone, a reciprocating compressor operating mode alone, a screw compressor and reciprocating compressor operating mode in coordination, a screw compressor and reciprocating compressor operating mode with coordinated gas supply, and an over-condition operating mode; the unit is equipped with a wireless remote transmission module, and the host computer is connected to a cloud-based management and control platform, supporting real-time access from multiple terminals to achieve remote monitoring and control.

[0006] When the intake pressure is 0-50 psig, the exhaust pressure is ≤400 psig, and the flow rate is ≤5 MMSCFD, the screw compressor operates alone; when the intake pressure is 50-600 psig, the exhaust pressure is 400-1200 psig, and the flow rate is ≤7 MMSCFD, the reciprocating compressor operates alone; when the intake pressure is 0-50 psig, the exhaust pressure is 400-1200 psig, and the flow rate is ≤5 MMSCFD, the screw compressor and reciprocating compressor operate in tandem; when the intake pressure is 0-50 psig, the exhaust pressure is 400-1200 psig, and the flow rate is 5-7 MMSCFD, the screw compressor and reciprocating compressor operate in tandem with supplemental air; when the intake pressure is 600-1200 psig and the exhaust pressure is 600-1200 psig, the over-condition operation mode is used.

[0007] Preferably, in the independent operation mode of the screw compressor, the process gas passes through the screw compressor intake pipeline, and the first intake pressure transmitter of the screw compressor unit monitors the intake pressure. When the intake pressure is 0-50 psig, the system controls the first intake automatic switch valve / first exhaust automatic switch valve to open and the first bypass automatic switch valve to close, and the screw compressor starts operating.

[0008] Since the screw compressor discharge pressure is ≤400 psig, the system monitors the first discharge pressure transmitter of the screw compressor unit. If the pressure is ≤400 psig, the system also monitors the second discharge pressure transmitter of the reciprocating compressor unit. If the pressure is ≤400 psig, the interlocking mechanism is triggered. The system controls the second intake automatic switch valve and the second discharge automatic switch valve to automatically close, and the second bypass automatic switch valve to automatically open. The second flow transmitter monitors the discharge flow rate as ≤5MMSCFD. Since there is no higher flow rate requirement input from the system, the make-up air automatic control valve automatically closes.

[0009] Preferably, in the reciprocating compressor's stand-alone operation mode, the process gas is monitored by the first inlet pressure transmitter of the screw compressor unit. When the inlet pressure is 50-600 psig, the system controls the first inlet automatic switching valve / first exhaust automatic switching valve to close and the first bypass automatic switching valve to open, and the screw compressor does not run.

[0010] The process gas enters the intake pipeline of the reciprocating compressor unit through the first bypass automatic switching valve of the screw compressor unit. The system monitors the pressure of the second intake pressure transmitter of the reciprocating compressor unit (50-600 psig) and the pressure of the second discharge pressure transmitter of the reciprocating compressor unit (400-1200 psig), triggering the interlock mechanism. The system controls the second intake automatic switching valve and the second discharge automatic switching valve to open automatically, and the second bypass automatic switching valve to close automatically. The second flow transmitter monitors the discharge flow. The system automatically opens or closes the make-up gas control valve according to whether there is a higher flow requirement for the gas from the upstream pipeline.

[0011] Preferably, in the coordinated operation mode of the screw compressor and the reciprocating compressor, the process gas enters through the screw compressor intake pipeline, and the first intake pressure transmitter of the screw compressor unit monitors the intake pressure. When the intake pressure is 0-50 psig, the system controls the first intake automatic switch valve and the first exhaust automatic switch valve to open, and the first bypass automatic switch valve to close, and the screw compressor starts.

[0012] Since the screw compressor discharge pressure is ≤400 psig, the system monitors the first discharge pressure transmitter of the screw compressor unit. If the pressure is ≤400 psig, the system monitors the second discharge pressure transmitter of the reciprocating compressor unit. If the pressure is between 400-1200 psig, the system controls the second bypass automatic switch valve to automatically close, and the second intake automatic switch valve and the second discharge automatic switch valve to automatically open. If the second flow transmitter of the reciprocating compressor unit monitors the discharge flow rate as ≤5MMSCFD, and the system has no higher flow rate input requirement, the make-up air automatic control valve will automatically close.

[0013] Preferably, in the coordinated operation mode of the screw compressor and reciprocating compressor, the process gas enters through the screw compressor intake pipeline. The first intake pressure transmitter of the screw compressor unit monitors the intake pressure. When the intake pressure is 0-50 psig, the system controls the first intake automatic switch valve and the first exhaust automatic switch valve to open, and the first bypass automatic switch valve to close, thus starting the screw compressor.

[0014] Since the screw compressor discharge pressure is ≤400 psig, the system monitors the first discharge pressure transmitter of the screw compressor unit. If the pressure is ≤400 psig, the system monitors the second discharge pressure transmitter of the reciprocating compressor unit. If the pressure is between 400-1200 psig, the system controls the second bypass automatic switch valve to automatically close, and the second intake automatic switch valve and the second discharge automatic switch valve to automatically open. If the second flow transmitter of the reciprocating compressor unit monitors the discharge flow rate as ≤5MMSCFD, and the system has a higher flow rate input, the automatic gas supply control valve will automatically open to supply gas.

[0015] Preferably, in the over-condition operation mode, the process gas enters through the screw compressor intake pipeline. The first intake pressure transmitter of the screw compressor unit monitors the intake pressure. When the intake pressure is 600-1200 psig, the system controls the first intake automatic switching valve, the first exhaust automatic switching valve, the second intake automatic switching valve, the second exhaust automatic switching valve, the first reflux automatic regulating valve, the make-up gas automatic control valve, and the second reflux automatic regulating valve to close, while the first bypass automatic switching valve and the second bypass automatic switching valve open. The high-pressure gas is discharged through the screw compressor unit inlet pipeline, the first bypass automatic switching valve, the reciprocating compressor unit inlet pipeline, the second bypass automatic switching valve, and the reciprocating compressor unit outlet pipeline.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Based on real-time perception and big data analysis of multi-source operating parameters, this invention innovatively constructs a full-process intelligent control architecture of "operating condition monitoring - mode matching - precise control - remote collaboration", realizing intelligent switching of multiple modes such as screw compressor running alone, reciprocating compressor running alone, screw compressor and reciprocating compressor running in coordination, screw compressor and reciprocating compressor running in coordination with gas supply, and over-operating condition operation.

[0017] 2. This invention is equipped with a wireless remote transmission module, which connects to a host computer to build a cloud management platform with functions such as remote monitoring, fault early warning, parameter distribution, and historical data tracing. It supports real-time access from multiple terminals and collaborative scheduling of clustered devices, completely breaking the geographical limitations and collaborative barriers of traditional control modes. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a diagram showing the configuration of the generator set according to the present invention; Figure 2 This is a PFD diagram illustrating the stand-alone operation mode of the screw compressor of the present invention; Figure 3 This is a PFD diagram illustrating the stand-alone operation mode of the reciprocating compressor of the present invention; Figure 4 This is a PFD diagram illustrating the coordinated operation mode of the screw compressor and reciprocating compressor of the present invention; Figure 5 This is a PFD diagram illustrating the coordinated gas supply operation mode of the screw compressor and reciprocating compressor of the present invention; Figure 6 This is a PFD diagram illustrating the super-condition operation mode of the present invention.

[0020] Explanation of reference numerals in the attached figures: 1-Screw compressor, 101-First drive motor, 102-First frequency converter, 103-First control cabinet, 104-Screw compressor slide valve position sensor, 105-First automatic intake valve, 106-First automatic exhaust valve, 107-First automatic bypass valve, 108-First automatic reflux regulating valve, 109-First intake pressure transmitter, 110-First exhaust pressure transmitter, 111-First flow transmitter, 2-Reciprocating compressor, 201-Second drive motor, 202-Second frequency converter, 203-Second control cabinet, 204-Automatic air replenishment control valve, 205-Second automatic intake valve, 206-Second automatic exhaust valve, 207-Second automatic bypass valve, 208-Second automatic reflux regulating valve, 209-Second intake pressure transmitter, 210-Second exhaust pressure transmitter, 211-Second flow transmitter, 3-Host computer. Detailed Implementation

[0021] The invention will now be described in detail with reference to the accompanying drawings, by way of example. Obviously, the described embodiments are only some embodiments of the invention, and not all embodiments. Example

[0022] like Figure 1 As shown, the screw compressor can handle inlet pressures of 0-50 psig, exhaust pressures of ≤400 psig, and a maximum flow rate of 5 MMSCFD; the reciprocating compressor can handle inlet pressures of 50-600 psig, exhaust pressures of 400-1200 psig, and a maximum flow rate of 7 MMSCFD. To adapt to varying and wide-ranging operating conditions, a combined operation of the screw compressor and reciprocating compressor is adopted. This invention provides a multi-mode operation method for the coordinated use of a screw compressor and a reciprocating compressor. The multi-mode includes a screw compressor operating mode alone, a reciprocating compressor operating mode alone, a screw compressor and reciprocating compressor operating mode together, a screw compressor and reciprocating compressor operating mode with combined supplementary air supply, and an over-condition operating mode. The unit is equipped with a wireless remote transmission module, and the host computer 3 connects to the cloud management platform, supporting real-time access from multiple terminals to achieve remote monitoring and control.

[0023] 1. For example Figure 2 As shown, in the screw compressor's stand-alone operation mode, the inlet pressure is 0-50 psig, the outlet pressure is ≤400 psig, and the flow rate is ≤5 MMSCFD. The process gas enters through the screw compressor's inlet pipeline. The first inlet pressure transmitter 109 of the screw compressor unit monitors the inlet pressure. When the inlet pressure is 0-50 psig, the system controls the first inlet automatic switching valve 105 / first outlet automatic switching valve 106 to open and the first bypass automatic switching valve 107 to close, and the screw compressor 1 starts operating.

[0024] Since the discharge pressure of screw compressor 1 is ≤400 psig, the system monitors the first discharge pressure transmitter 110 of the screw compressor unit, which has a pressure ≤400 psig. At the same time, the system monitors the second discharge pressure transmitter 210 of the reciprocating compressor unit, which has a pressure ≤400 psig. This triggers the interlock mechanism, causing the system to automatically close the second intake automatic switch valve 205 and the second discharge automatic switch valve 206, and automatically open the second bypass automatic switch valve 207. The second flow transmitter 211 monitors the discharge flow rate as ≤5MMSCFD. Since the system has no higher flow rate input requirement, the make-up air automatic control valve 204 automatically closes.

[0025] Automatic control based on intake pressure Based on the pressure regulation monitored by the first intake pressure transmitter 109, unloading occurs when the intake pressure is below -2 psig. If the frequency of the first drive motor 101 is higher than 30 Hz, the first frequency converter 102 controls the frequency of the first drive motor 101 to automatically decrease; if the frequency decreases to 30 Hz but unloading is still required, the slide valve is controlled to unload, and its position is monitored by the screw compressor slide valve position sensor 104. If the slide valve is lowered to its minimum position and unloading is still required, the first return flow automatic regulating valve 108 is opened slowly and sequentially for adjustment.

[0026] When the first intake pressure transmitter 109 detects a pressure higher than 52 psig, loading is initiated. First, the first automatic backflow regulating valve 108 is closed slowly and sequentially. After closure, the slide valve is automatically controlled to load, with its position monitored by the screw compressor slide valve position sensor 104. When the slide valve reaches the 100% loading position and further loading is required, the first frequency converter 102 controls the first drive motor 101 to increase its frequency from 30 Hz. At this time, the PLC displays the full-load position of the slide valve.

[0027] Automatic control based on exhaust flow input value The user inputs the target flow rate into the human-machine interface system of the first control cabinet 103 or the host computer 3, and the unit automatically adjusts. The control system maintains a stable outlet target flow rate by automatically adjusting the flow rate through the following three methods: the first frequency converter 102 adjusts the motor speed (100%-50% flow range), the slide valve (50%-10% flow range), and the first automatic backflow regulating valve 108 (10%-0% flow range).

[0028] If the user inputs a target flow rate, and this target flow rate is greater than the actual flow rate read by the first flow transmitter 111, a loading procedure is executed until the actual flow rate read by the first flow transmitter 111 reaches the user-input target flow rate. If the target flow rate is less than the actual flow rate read by the first flow transmitter 111, a unloading procedure is executed until the actual flow rate read by the first flow transmitter 111 reaches the user-input target flow rate. The automatic adjustment must not deviate from the pressure range specified in the automatic pressure control mechanism. If it does, the inlet pressure will be maintained first, followed by flow rate adjustment.

[0029] At this time, screw compressor 1 operates alone, while reciprocating compressor 2 does not operate.

[0030] 2. For example Figure 3 As shown, in the reciprocating compressor's stand-alone operation mode, the inlet pressure is 50-600 psig, the outlet pressure is 400-1200 psig, and the flow rate is ≤7 MMSCFD. The process gas is monitored by the first inlet pressure transmitter 109 of the screw compressor unit. When the inlet pressure is 50-600 psig, the system controls the first inlet automatic switching valve 105 / first outlet automatic switching valve 106 to close and the first bypass automatic switching valve 107 to open, and the screw compressor 1 does not run.

[0031] The process gas enters the intake pipeline of the reciprocating compressor unit via the first bypass automatic switching valve 107 of the screw compressor unit. The system monitors the pressure of the second intake pressure transmitter 209 of the reciprocating compressor unit (50-600 psig) and the pressure of the second discharge pressure transmitter 210 of the reciprocating compressor unit (400-1200 psig), triggering the interlock mechanism. The system controls the second intake automatic switching valve 205 and the second discharge automatic switching valve 206 to open automatically, and the second bypass automatic switching valve 207 to close automatically. The second flow transmitter 211 monitors the discharge flow. The system automatically opens or closes the make-up gas control valve 204 based on whether there is a higher flow requirement for the gas from the upstream pipeline.

[0032] Automatic control based on intake pressure Based on the pressure regulation monitored by the second intake pressure transmitter 209, unloading occurs when the intake pressure is below 48 psig. If the frequency of the second drive motor 201 is higher than 30 Hz, the second frequency converter 202 controls the frequency of the second drive motor 201 to automatically decrease; if the frequency decreases to 30 Hz and unloading is still required, the second return flow automatic regulating valve 208 is slowly opened sequentially for adjustment.

[0033] When the second intake pressure transmitter 209 detects a pressure higher than 602 psig, loading is initiated. First, the second automatic reflux regulating valve 208 is closed slowly and sequentially. After closure, the second frequency converter 202 automatically controls the second drive motor 201 to start increasing its frequency from 30 Hz.

[0034] Automatic control based on exhaust flow input value The user inputs the target flow rate into the human-machine interface system of the second control cabinet 203 or the host computer 3, and the unit automatically adjusts. The control system maintains a stable outlet target flow rate by automatically adjusting the flow rate through the following three methods: the second frequency converter 202 adjusts the motor speed (100%-50% flow range) and the second backflow automatic regulating valve 208 (50%-0% flow range).

[0035] If the user inputs a target flow rate, and this target flow rate is greater than the actual flow rate read by the second flow transmitter 211, a loading procedure is executed until the actual flow rate read by the second flow transmitter 211 reaches the user-input target flow rate. If the target flow rate is less than the actual flow rate read by the second flow transmitter 211, a unloading procedure is executed until the actual flow rate read by the second flow transmitter 211 reaches the user-input target flow rate. The automatic adjustment must not deviate from the pressure range specified in the automatic pressure control protocol. If it does, the inlet pressure will be maintained first, followed by flow rate adjustment.

[0036] At this time, reciprocating compressor 2 operates alone, while screw compressor 1 does not operate.

[0037] 3. For example Figure 4 As shown, in the coordinated operation mode of the screw compressor and reciprocating compressor, the inlet pressure is 0-50 psig, the outlet pressure is 400-1200 psig, and the flow rate is ≤5 MMSCFD. The process gas enters through the screw compressor inlet pipeline. The first inlet pressure transmitter 109 of the screw compressor unit monitors the inlet pressure. When the inlet pressure is 0-50 psig, the system controls the first inlet automatic switching valve 105 and the first outlet automatic switching valve 106 to open, and the first bypass automatic switching valve 107 to close, and the screw compressor 1 starts.

[0038] Since the discharge pressure of screw compressor 1 is ≤400 psig, the system monitors the first discharge pressure transmitter 110 of the screw compressor unit to ensure the pressure is ≤400 psig. At the same time, the system monitors the second discharge pressure transmitter 210 of the reciprocating compressor unit. If the pressure is between 400-1200 psig, the system controls the second bypass automatic switching valve 207 to automatically close, and the second intake automatic switching valve 205 and the second discharge automatic switching valve 206 to automatically open. The second flow transmitter 211 of the reciprocating compressor unit monitors the discharge flow rate to be ≤5MMSCFD. Since the system has no higher flow rate requirement, the make-up air automatic control valve 204 automatically closes.

[0039] Automatic control based on screw compressor intake pressure Based on the pressure regulation monitored by the first intake pressure transmitter 109, unloading is initiated when the intake pressure drops below -2 psig. Reciprocating compressor 2 is automatically unloaded first, following the unloading sequence in the reciprocating compressor standalone operation mode. If the intake pressure remains below -2 psig after reciprocating compressor 2 has finished unloading, the unloading sequence in the screw compressor standalone operation mode is then repeated. If the intake pressure remains below -2 psig after both units have finished unloading, this condition exceeds the unit's performance range, and a shutdown procedure is executed.

[0040] When the first inlet pressure transmitter 109 detects a pressure higher than 52 psig, loading begins. Screw compressor 1 is loaded automatically first, following the loading sequence in the screw compressor standalone operation mode. If the inlet pressure remains higher than 52 psig after screw compressor 1 has finished loading, the loading sequence in the reciprocating compressor standalone operation mode is then repeated. If the inlet pressure remains higher than 52 psig after both units have finished loading, this condition exceeds the unit's performance range, and a shutdown procedure is executed.

[0041] Automatic control based on exhaust flow input value The user inputs a target flow rate in the human-machine interface system of the host computer 3, and the control system automatically adjusts according to the target flow rate. If the input target flow rate is greater than the actual flow rate read by the second flow transmitter 211, the loading program is executed until the actual flow rate read by the second flow transmitter 211 reaches the user-input target flow rate. During loading, screw compressor 1 is loaded automatically first, following the loading order in the screw compressor standalone operation mode. If, after screw compressor 1 has finished loading, the input target flow rate is still greater than the actual flow rate read by the second flow transmitter 211, the loading order in the reciprocating compressor standalone operation mode is then followed sequentially. If both units have finished loading, and the input target flow rate is still greater than the actual flow rate read by the second flow transmitter 211, the maximum operating condition of both units is maintained.

[0042] If the input target flow rate is less than the actual flow rate read by the second flow transmitter 211, a load reduction procedure will be executed until the actual flow rate read by the second flow transmitter 211 reaches the user-input target flow rate. During load reduction, the reciprocating compressor 2 will be automatically unloaded first, following the unloading sequence in the reciprocating compressor standalone operation mode. If, after the reciprocating compressor 2 has finished unloading, the input target flow rate is still less than the actual flow rate read by the second flow transmitter 211, the unloading sequence in the screw compressor standalone operation mode will be followed, and the unloading will proceed sequentially. If both units have finished unloading, and the input target flow rate is still less than the actual flow rate read by the second flow transmitter 211, the operating state of both units under minimum operating conditions will be maintained. The above automatic adjustments must not deviate from the pressure range in the above automatic pressure control. If they deviate, the inlet pressure will be maintained first, and then flow rate adjustment will be performed.

[0043] At this time, screw compressor 1 is running and reciprocating compressor 2 is running, working together.

[0044] 4. For example Figure 5 As shown, in the coordinated operation mode of the screw compressor and reciprocating compressor with supplemental gas, the inlet pressure is 0-50 psig, the outlet pressure is 400-1200 psig, and the flow rate is 5-7 MMSCFD. The process gas enters through the screw compressor inlet pipeline. The first inlet pressure transmitter 109 of the screw compressor unit monitors the inlet pressure. When the inlet pressure is 0-50 psig, the system controls the first inlet automatic switching valve 105 and the first outlet automatic switching valve 106 to open, and the first bypass automatic switching valve 107 to close, and the screw compressor 1 starts.

[0045] Since the discharge pressure of screw compressor 1 is ≤400 psig, the system monitors the first discharge pressure transmitter 110 of the screw compressor unit to ensure the pressure is ≤400 psig. At the same time, the system monitors the second discharge pressure transmitter 210 of the reciprocating compressor unit. If the pressure is between 400-1200 psig, the system controls the second bypass automatic switching valve 207 to automatically close, and the second intake automatic switching valve 205 and the second discharge automatic switching valve 206 to automatically open. The second flow transmitter 211 of the reciprocating compressor unit monitors the discharge flow rate to be ≤5MMSCFD. If the system has a higher flow rate requirement, the automatic gas supply control valve 204 will automatically open to supply gas.

[0046] Automatic control based on screw compressor intake pressure Based on the pressure regulation monitored by the first intake pressure transmitter 109, unloading is initiated when the intake pressure drops below -2 psig. Reciprocating compressor 2 is automatically unloaded first, following the unloading sequence in the reciprocating compressor standalone operation mode. If the intake pressure remains below -2 psig after reciprocating compressor 2 has finished unloading, the unloading sequence in the screw compressor standalone operation mode is then repeated. If the intake pressure remains below -2 psig after both units have finished unloading, this condition exceeds the unit's performance range, and a shutdown procedure is executed.

[0047] When the first inlet pressure transmitter 109 detects a pressure higher than 52 psig, loading begins. Screw compressor 1 is loaded automatically first, following the loading sequence in the screw compressor standalone operation mode. If the inlet pressure remains higher than 52 psig after screw compressor 1 has finished loading, the loading sequence in the reciprocating compressor standalone operation mode is then repeated. If the inlet pressure remains higher than 52 psig after both units have finished loading, this condition exceeds the unit's performance range, and a shutdown procedure is executed.

[0048] Automatic control based on exhaust flow input value The user inputs the target flow rate in the human-machine interface system of the host computer 3, and the control system automatically adjusts according to the target flow rate. If the input target flow rate is greater than the actual flow rate read by the second flow transmitter 211, the loading program is executed until the actual flow rate read by the second flow transmitter 211 reaches the user's input target flow rate. During loading, screw compressor 1 is loaded automatically first, and then loaded sequentially according to the loading order in the screw compressor's standalone operation mode. If the input target flow rate is still greater than the actual flow rate read by the second flow transmitter 211 after screw compressor 1 has finished loading, the loading order in the reciprocating compressor's standalone operation mode is then followed sequentially. If both units have finished loading, and the input target flow rate is still greater than the actual flow rate read by the second flow transmitter 211, and the input target flow rate is ≤5MMSCFD (the maximum flow rate of the screw compressor), then the maximum operating condition of both units is maintained. If the input target flow rate is greater than 5MMSCFD (the maximum flow rate of the screw compressor), then the reciprocating compressor's automatic gas supply control valve 204 is opened slowly and automatically to supply gas. If the reciprocating compressor gas replenishment automatic control valve 204 is fully open, and the input target flow rate is still greater than the actual flow rate read by the second flow transmitter 211, then the maximum operating condition of both units will be maintained.

[0049] If the input target flow rate is less than the actual flow rate read by the second flow transmitter 211, a load reduction procedure will be executed until the actual flow rate read by the second flow transmitter 211 reaches the user-input target flow rate. If the input target flow rate is greater than 5MMSCFD (the maximum flow rate of the screw compressor), during load reduction, the reciprocating compressor's automatic gas supply control valve 204 will be closed sequentially and slowly to reduce gas supply. If the input target flow rate is less than 5MMSCFD (the maximum flow rate of the screw compressor), the reciprocating compressor's automatic gas supply control valve 204 will be ensured to be completely closed, and the reciprocating compressor 2 will be automatically unloaded first, following the unloading sequence in the reciprocating compressor's stand-alone operation mode. If, after the reciprocating compressor 2 has been unloaded, the input target flow rate is still less than the actual flow rate read by the second flow transmitter 211, the unloading sequence in the screw compressor's stand-alone operation mode will be followed again. If both units have been unloaded and the input target flow rate is still less than the actual flow rate read by the second flow transmitter 211, the operating state of both units under minimum operating conditions will be maintained. The above automatic adjustments must not deviate from the pressure range specified in the automatic pressure control. If they do deviate, the inlet pressure will be prioritized before flow rate adjustment.

[0050] At this time, screw compressor 1 is running and reciprocating compressor 2 is running (inlet gas supply), working together.

[0051] 5. For example Figure 6 As shown, in the over-condition operation mode, the intake pressure is 600-1200 psig and the exhaust pressure is 600-1200 psig. The process gas enters through the screw compressor intake pipeline. The first intake pressure transmitter 109 of the screw compressor unit monitors the intake pressure. When the intake pressure is 600-1200 psig, the system controls the first intake automatic switching valve 105, the first exhaust automatic switching valve 106, the second intake automatic switching valve 205, the second exhaust automatic switching valve 206, the first reflux automatic regulating valve 108, the make-up gas automatic control valve 204, and the second reflux automatic regulating valve 208 to close, while the first bypass automatic switching valve 107 and the second bypass automatic switching valve 207 open. The high-pressure gas is discharged through the screw compressor unit inlet pipeline, the first bypass automatic switching valve 107, the reciprocating compressor unit inlet pipeline, the second bypass automatic switching valve 207, and the reciprocating compressor unit outlet pipeline.

[0052] At this time, neither screw compressor 1 nor reciprocating compressor 2 is running.

[0053] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and application concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A multi-mode operation method for the coordinated operation of a screw compressor and a reciprocating compressor, characterized in that: The multi-mode includes screw compressor stand-alone operation mode, reciprocating compressor stand-alone operation mode, screw compressor and reciprocating compressor co-operation mode, screw compressor and reciprocating compressor co-operation mode with gas replenishment and operation mode and over-condition operation mode; the unit is equipped with a wireless remote transmission module, and the host computer (3) is connected to the cloud management platform, which supports real-time access of multiple terminals to realize remote monitoring and control; When the intake pressure is 0-50 psig, the exhaust pressure is ≤400 psig, and the flow rate is ≤5 MMSCFD, the screw compressor operates in stand-alone mode. When the intake pressure is 50-600 psig, the exhaust pressure is 400-1200 psig, and the flow rate is ≤7 MMSCFD, the reciprocating compressor operates alone. When the intake pressure is 0-50 psig, the exhaust pressure is 400-1200 psig, and the flow rate is ≤5 MMSCFD, the screw compressor and reciprocating compressor operate in a coordinated mode. When the intake pressure is 0-50 psig, the exhaust pressure is 400-1200 psig, and the flow rate is 5-7 MMSCFD, the screw compressor and reciprocating compressor are used in a coordinated supplemental air operation mode. When the intake pressure is 600-1200 psig and the exhaust pressure is 600-1200 psig, the over-condition operation mode is adopted.

2. The multi-mode operation method for the coordinated operation of a screw compressor and a reciprocating compressor as described in claim 1, characterized in that: In the independent operation mode of the screw compressor, the process gas enters through the screw compressor intake pipeline. The first intake pressure transmitter (109) of the screw compressor unit monitors the intake pressure. When the intake pressure is 0-50 psig, the system controls the first intake automatic switch valve (105) / the first exhaust automatic switch valve (106) to open and the first bypass automatic switch valve (107) to close, and the screw compressor (1) runs. Since the discharge pressure of the screw compressor (1) is ≤400 psig, the system monitors the first discharge pressure transmitter (110) of the screw compressor unit, which has a pressure ≤400 psig. At the same time, the system monitors the second discharge pressure transmitter (210) of the reciprocating compressor unit, which has a pressure ≤400 psig. This triggers the interlock mechanism, and the system controls the second intake automatic switch valve (205) and the second discharge automatic switch valve (206) to close automatically. The second bypass automatic switch valve (207) opens automatically. The second flow transmitter (211) monitors the discharge flow rate as ≤5MMSCFD. Since the system has no higher flow rate input, the make-up air automatic control valve (204) closes automatically.

3. The multi-mode operation method for the coordinated operation of a screw compressor and a reciprocating compressor as described in claim 1, characterized in that: In the stand-alone operation mode of the reciprocating compressor, the process gas is monitored by the first inlet pressure transmitter (109) of the screw compressor unit. When the inlet pressure is 50-600 psig, the system controls the first inlet automatic switch valve (105) / the first exhaust automatic switch valve (106) to close and the first bypass automatic switch valve (107) to open, and the screw compressor (1) does not run. The process gas enters the intake pipeline of the reciprocating compressor unit through the first bypass automatic switching valve (107) of the screw compressor unit. The system monitors the pressure of the second intake pressure transmitter (209) of the reciprocating compressor unit (50-600 psig) and the pressure of the second exhaust pressure transmitter (210) of the reciprocating compressor unit (400-1200 psig), triggering the interlock mechanism. The system controls the second intake automatic switching valve (205) and the second exhaust automatic switching valve (206) to open automatically, and the second bypass automatic switching valve (207) to close automatically. The second flow transmitter (211) monitors the exhaust flow. The system automatically opens or closes the gas replenishment automatic control valve (204) according to whether there is a higher flow requirement for the gas from the front-end pipeline.

4. The multi-mode operation method for the coordinated operation of a screw compressor and a reciprocating compressor as described in claim 1, characterized in that: In the coordinated operation mode of the screw compressor and reciprocating compressor, the process gas enters through the screw compressor intake pipeline. The first intake pressure transmitter (109) of the screw compressor unit monitors the intake pressure. When the intake pressure is 0-50 psig, the system controls the first intake automatic switch valve (105) and the first exhaust automatic switch valve (106) to open, and the first bypass automatic switch valve (107) to close, and the screw compressor (1) starts. Since the discharge pressure of the screw compressor (1) is ≤400 psig, the system monitors the first discharge pressure transmitter (110) of the screw compressor unit to ensure that the pressure is ≤400 psig. At the same time, the system monitors the second discharge pressure transmitter (210) of the reciprocating compressor unit. If the pressure is between 400-1200 psig, the system controls the second bypass automatic switch valve (207) to automatically close, and the second intake automatic switch valve (205) and the second discharge automatic switch valve (206) to automatically open. The second flow transmitter (211) of the reciprocating compressor unit monitors the discharge flow rate to be ≤5MMSCFD. Since the system has no higher flow rate input, the automatic air replenishment control valve (204) automatically closes.

5. The multi-mode operation method for the coordinated operation of a screw compressor and a reciprocating compressor as described in claim 1, characterized in that: In the coordinated operation mode of the screw compressor and reciprocating compressor, the process gas enters through the screw compressor intake pipeline. The first intake pressure transmitter (109) of the screw compressor unit monitors the intake pressure. When the intake pressure is 0-50 psig, the system controls the first intake automatic switch valve (105) and the first exhaust automatic switch valve (106) to open, and the first bypass automatic switch valve (107) to close, and the screw compressor (1) starts. Since the discharge pressure of the screw compressor (1) is ≤400 psig, the system monitors the first discharge pressure transmitter (110) of the screw compressor unit to ensure that the pressure is ≤400 psig. At the same time, the system monitors the second discharge pressure transmitter (210) of the reciprocating compressor unit. If the pressure is between 400-1200 psig, the system controls the second bypass automatic switch valve (207) to automatically close, and the second intake automatic switch valve (205) and the second discharge automatic switch valve (206) to automatically open. The second flow transmitter (211) of the reciprocating compressor unit monitors the discharge flow rate to be ≤5MMSCFD. If the system has a higher flow rate input, the automatic gas supply control valve (204) will automatically open to supply gas.

6. The multi-mode operation method for the coordinated operation of a screw compressor and a reciprocating compressor as described in claim 1, characterized in that: In the over-condition operation mode, the process gas enters through the screw compressor intake pipeline. The first intake pressure transmitter (109) of the screw compressor unit monitors the intake pressure. When the intake pressure is 600-1200 psig, the system controls the first intake automatic switch valve (105), the first exhaust automatic switch valve (106), the second intake automatic switch valve (205), the second exhaust automatic switch valve (206), the first reflux automatic regulating valve (108), the make-up gas automatic control valve (204), and the second reflux automatic regulating valve (208) to close, and the first bypass automatic switch valve (107) and the second bypass automatic switch valve (207) to open. The high-pressure gas is discharged through the screw compressor unit inlet pipeline, the first bypass automatic switch valve (107), the reciprocating compressor unit inlet pipeline, the second bypass automatic switch valve (207), and the reciprocating compressor unit outlet pipeline.

Images