A guide vane control system for air compressor

Abstract

The present invention discloses an air compressor guide vane control system, comprising: a DCS control system, a guide vane position feedback device, and a guide vane actuator composed of a double-acting pneumatic actuator and a guide vane connecting rod mechanism for driving the guide vane movement, and also comprising a throat difference feedback device and a guide vane limit mechanism, wherein the guide vane limit mechanism comprises: a limit block located directly in front of the driving end of the guide vane connecting rod mechanism of the guide vane actuator, and the limit block is controlled by a limit block moving mechanism; the guide vane position feedback device, the throat difference feedback device, the double-acting pneumatic actuator of the guide vane actuator, and the limit block moving mechanism of the guide vane limit mechanism are simultaneously connected to the DCS control system signal. The present invention has the advantages of effectively preventing the air compressor interlocking shutdown caused by the failure of the guide vane actuator and the failure of a single guide vane position feedback device, thereby ensuring the stable and safe operation of the air separation system.

Description

Technical Field

[0001] The invention relates to the technical field of air compressor guide vane control, and in particular to an air compressor guide vane control system. Background Art

[0002] The structure of the air compressor guide vane control system currently used includes: a DCS control system, a guide vane position feedback device for real-time monitoring of the guide vane position and feeding back to the DCS control system, and a guide vane actuator for driving the guide vane to move. The guide vane actuator includes a double-acting pneumatic actuator and a guide vane connecting rod mechanism. The guide vane connecting rod mechanism is used to connect the guide vane shafts of each guide vane together to ensure that the guide vane shafts can rotate synchronously at the same time. The piston rod of the double-acting pneumatic actuator is connected to the driving end of the guide vane connecting rod mechanism, and the guide vane connecting rod mechanism is actuated by pushing the driving end to move forward and backward; the guide vane position feedback device and the double-acting pneumatic actuator in the guide vane actuator are simultaneously connected to the DCS control system signal.

[0003] During operation, when it is necessary to adjust the opening of each guide vane of the air compressor, the DCS control system controls the piston rod of the double-acting pneumatic actuator in the guide vane actuator to extend forward or retract backward, driving the driving end of the guide vane linkage mechanism in the guide vane actuator to move forward or backward, thereby driving the guide vane linkage mechanism to move, driving all the guide vane shafts to rotate synchronously at the same time, and then driving all the guide vanes to rotate, so as to adjust the opening of each guide vane; in actual production, when the piston rod of the double-acting pneumatic actuator drives the driving end of the guide vane linkage mechanism to move forward, The guide vane linkage mechanism will drive each guide vane to rotate in the direction of gradually decreasing opening. When the piston rod of the double-acting pneumatic actuator drives the driving end of the guide vane linkage mechanism to move backward, the guide vane linkage mechanism will drive each guide vane to rotate in the direction of gradually increasing opening. In addition, during the operation of the air compressor, the DCS control system will collect the guide vane position signal fed back by the guide vane position feedback device in real time. When the DCS control system determines that the guide vane opening is less than the safety interlock value (the safety interlock value is generally 25°), the DCS control system will control the air compressor to shut down.

[0004] The above-mentioned air compressor guide vane control system has the following disadvantages: (1) When the guide vane actuator of the air compressor fails, the guide vane opening will suddenly decrease. When the DCS control system determines that the guide vane opening is less than 25°, the DCS control system will control the air compressor to shut down, causing fluctuations in the air supply volume of the air separation system, seriously affecting the safe operation of the air separation system; (2) When the guide vane position feedback device fails, it will send an erroneous guide vane position signal to the DCS control system. When the DCS control system determines that the guide vane opening is less than 25° based on the erroneous guide vane position signal, the DCS control system will control the air compressor to shut down, causing fluctuations in the air supply volume of the air separation system, seriously affecting the safe operation of the air separation system. Summary of the invention

[0005] The object of the present invention is to provide an air compressor guide vane control system with high operating stability and use safety.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: the guide vane control system of an air compressor comprises: a DCS control system, a guide vane position feedback device for real-time monitoring the guide vane position and feeding back to the DCS control system, and a guide vane actuator composed of a double-acting pneumatic actuator and a guide vane connecting rod mechanism for driving the guide vane movement, and also comprises a throat difference feedback device for real-time monitoring the throat difference of the air compressor inlet throat and feeding back to the DCS control system, and a guide vane limiting mechanism for limiting the guide vane position, wherein the guide vane limiting mechanism is a plurality of guide vane actuators, a plurality of guide vane actuators, and a plurality of guide vane actuators. The positioning mechanism includes: a limit stopper located directly in front of the driving end of the guide vane linkage mechanism of the guide vane actuator, the limit stopper is controlled by a limit stopper moving mechanism, and the limit stopper can move toward the driving end of the guide vane linkage mechanism under the drive of the limit stopper moving mechanism to block the driving end of the guide vane linkage mechanism from moving forward, or leave the driving end of the guide vane linkage mechanism; the guide vane position feedback device, the throat difference feedback device, the double-acting pneumatic actuator of the guide vane actuator and the limit stopper moving mechanism of the guide vane limit mechanism are simultaneously connected to the DCS control system signal.

[0007] Furthermore, the aforementioned air compressor guide vane control system, wherein: the limit block moving mechanism includes: a single-acting pneumatic actuator and a two-position three-way solenoid valve, the piston rod of the single-acting pneumatic actuator is connected to the limit block, and the air inlet of the single-acting pneumatic actuator is connected to the air outlet side of the two-position three-way solenoid valve.

[0008] Furthermore, in the aforementioned air compressor guide vane control system, the throat difference feedback device is a differential pressure transmitter installed at the air compressor inlet throat and connected to the DCS control system signal.

[0009] Through the implementation of the above technical scheme, the beneficial effects of the present invention are: (1) the guide vane position is indirectly limited by the limit block, which effectively prevents the guide vane opening from suddenly decreasing when the guide vane actuator of the air compressor fails, thereby not causing fluctuations in the air supply volume of the air separation system and shutdown of the air compressor, thereby ensuring the stable and safe operation of the air separation system, and having high operating stability and safety in use; (2) the guide vane position signal fed back by the guide vane position feedback device and the throat difference signal of the air compressor inlet throat fed back by the throat difference feedback device are used to determine whether the air compressor needs to be shut down in an interlocking manner, thereby avoiding the air compressor interlocking shutdown caused by a single guide vane position feedback device failure, thereby further ensuring the stable and safe operation of the air separation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 The present invention is a schematic diagram of the structural principle of an air compressor guide vane control system. DETAILED DESCRIPTION

[0011] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0012] like Figure 1 As shown, the guide vane control system of an air compressor comprises: a DCS control system 1, a guide vane position feedback device 2 for real-time monitoring the position of the guide vane 11 and feeding back to the DCS control system 1, and a guide vane actuator 3 composed of a double-acting pneumatic actuator 31 and a guide vane connecting rod mechanism 32 for driving the guide vane movement, and also comprises a throat difference feedback device 5 for real-time monitoring the throat difference of the inlet throat of the air compressor 4 and feeding back to the DCS control system 1, and a guide vane limiting mechanism 6 for limiting the position of the guide vane 11, the guide vane limiting mechanism 6 comprises: a limit stopper 61 located directly in front of the driving end 321 of the guide vane connecting rod mechanism 32 of the guide vane actuator 3, the limit stopper 61 is controlled by the limit stopper moving mechanism, and the limit stopper 61 can move toward the driving end 321 of the guide vane connecting rod mechanism 32 under the drive of the limit stopper moving mechanism to block The driving end 321 of the guide vane linkage mechanism 32 moves forward or leaves the driving end 321 of the release guide vane linkage mechanism 32; the guide vane position feedback device 2, the throat difference feedback device 5, the double-acting pneumatic actuator 31 of the guide vane actuator 3 and the limit stopper moving mechanism of the guide vane limit mechanism 6 are simultaneously connected to the DCS control system 1 by signal; in this embodiment, the limit stopper moving mechanism includes: a single-acting pneumatic actuator 62 and a two-position three-way solenoid valve 63, the piston rod of the single-acting pneumatic actuator 62 is connected to the limit stopper 61, and the air inlet of the single-acting pneumatic actuator 62 is connected to the air outlet side of the two-position three-way solenoid valve 63, and the above-mentioned limit stopper moving mechanism has a simple structure and is easy to install and maintain; in this embodiment, the throat difference feedback device 5 is a differential pressure transmitter installed at the inlet throat of the air compressor 4 and connected to the DCS control system 1 by signal;

[0013] The working principle of the present invention is as follows:

[0014] When the air compressor is in the start-up and shutdown state and the guide vane 11 opening needs to be adjusted significantly, the DCS control system 1 energizes the two-position three-way solenoid valve 63 to retract the piston rod of the single-acting pneumatic actuator 62, driving the limit block 61 to leave the driving end 321 of the guide vane linkage mechanism 32; then the DCS control system 1 controls the piston rod of the double-acting pneumatic actuator 31 in the guide vane actuator 3 to extend forward or retract backward, driving the driving end 321 of the guide vane linkage mechanism 32 in the guide vane actuator 3 to move forward or backward, and synchronously driving the guide vane linkage mechanism 32 to move, thereby driving all the guide vane shafts to rotate synchronously at the same time, and then driving all the guide vanes 11 to rotate, so as to adjust the opening of each guide vane 11. Adjustment is performed; after the guide vane opening is adjusted to the desired position, the DCS control system 1 de-energizes the two-position three-way solenoid valve 63, so that the piston rod of the single-acting pneumatic actuator 62 is extended, driving the limit stopper 61 to move the driving end 321 of the guide vane linkage mechanism 32 and blocking the driving end 321 of the guide vane linkage mechanism 32 from continuing to move forward. At this time, the driving end 321 of the guide vane linkage mechanism 32 is blocked by the limit stopper 61 and cannot move forward, thereby limiting the guide vane opening. In this way, when the guide vane actuator 3 of the air compressor fails, the guide vane opening will not suddenly decrease under the limiting action of the limit stopper 61, thereby not causing fluctuations in the air supply volume of the air separation system and shutdown of the air compressor, thereby ensuring stable and safe operation of the air separation system.

[0015] During the operation of the air compressor, the DCS control system 1 will collect the guide vane position signal fed back by the guide vane position feedback device 2 and the throat difference signal of the air compressor inlet throat fed back by the throat difference feedback device 5 in real time, and compare the collected real-time guide vane position signal with the real-time throat difference signal. When the guide vane opening is less than the safety interlock value, and the real-time throat difference fed back at this time does not match the real-time guide vane opening, the DCS control system 1 will not control the air compressor 4 to shut down. Only when the guide vane opening is less than the safety interlock value and the real-time throat difference fed back at this time matches the real-time guide vane opening, the DCS control system 1 will control the air compressor 4 to shut down, avoiding the chain shutdown of the air compressor caused by the failure of a single guide vane position feedback device 2, and further ensuring the stable and safe operation of the air separation system.

[0016] The advantages of the present invention are: (1) the guide vane position is indirectly limited by a limit block, which effectively prevents the guide vane opening from suddenly decreasing when a guide vane actuator of the air compressor fails, thereby preventing fluctuations in the air supply volume of the air separation system and shutdown of the air compressor, thereby ensuring stable and safe operation of the air separation system, and high operational stability and safety of use; (2) whether the air compressor needs to be shut down in an interlocking manner is determined by the guide vane position signal fed back by the guide vane position feedback device and the throat difference signal of the air compressor inlet throat fed back by the throat difference feedback device, thereby avoiding the air compressor interlocking shutdown caused by a single guide vane position feedback device failure, thereby further ensuring the stable and safe operation of the air separation system.

Claims

1. An air compressor guide vane control system, comprising: A DCS control system, a guide vane position feedback device for real-time monitoring of the guide vane position and feeding back to the DCS control system, and a guide vane actuator composed of a double-acting pneumatic actuator and a guide vane connecting rod mechanism for driving the guide vane movement, characterized in that: it also includes a throat difference feedback device for real-time monitoring of the throat difference of the air compressor inlet throat and feeding back to the DCS control system, and a guide vane limiting mechanism for limiting the guide vane position, the guide vane limiting mechanism comprising: a limit stopper located directly in front of the driving end of the guide vane connecting rod mechanism of the guide vane actuator, the limit stopper is controlled by a limit stopper moving mechanism, and the limit stopper can move the guide vane connecting rod mechanism under the drive of the limit stopper moving mechanism The driving end of the guide vane linkage mechanism moves to block the driving end of the guide vane linkage mechanism from moving forward, or leaves the driving end of the guide vane linkage mechanism; the guide vane position feedback device, the throat difference feedback device, the double-acting pneumatic actuator of the guide vane actuator mechanism, and the limit stopper moving mechanism of the guide vane limit mechanism are simultaneously connected to the DCS control system signal; the limit stopper moving mechanism includes: a single-acting pneumatic actuator and a two-position three-way solenoid valve, the piston rod of the single-acting pneumatic actuator is connected to the limit stopper, and the air inlet of the single-acting pneumatic actuator is connected to the air outlet side of the two-position three-way solenoid valve; the throat difference feedback device is a differential pressure transmitter installed at the inlet throat of the air compressor and connected to the DCS control system signal; When the air compressor is in the start-up or shutdown state and the guide vane opening needs to be adjusted significantly, the DCS control system energizes the two-position three-way solenoid valve to retract the piston rod of the single-acting pneumatic actuator, driving the limit block to leave the driving end of the guide vane linkage mechanism; then the DCS control system controls the piston rod of the double-acting pneumatic actuator in the guide vane actuator to extend forward or retract backward, driving the driving end of the guide vane linkage mechanism in the guide vane actuator to move forward or backward, and synchronously driving the guide vane linkage mechanism to move, thereby driving all the guide vane shafts to rotate synchronously at the same time, and then driving all the guide vanes to rotate, so as to Adjust the opening of each guide vane; after the guide vane opening is adjusted to the right position, the DCS control system de-energizes the two-position three-way solenoid valve, extends the piston rod of the single-acting pneumatic actuator, drives the limit block to move the driving end of the guide vane linkage mechanism and blocks the driving end of the guide vane linkage mechanism from continuing to move forward. At this time, the driving end of the guide vane linkage mechanism is blocked by the limit block and cannot move forward, thereby limiting the guide vane opening. In this way, when the guide vane actuator of the air compressor fails, the guide vane opening will not suddenly decrease under the limiting action of the limit block, thereby preventing fluctuations in the air supply volume of the air separation system and air compressor shutdown; During the operation of the air compressor, the DCS control system will collect the guide vane position signal fed back by the guide vane position feedback device and the throat difference signal of the air compressor inlet throat fed back by the throat difference feedback device in real time, and compare the collected real-time guide vane position signal with the real-time throat difference signal. When the guide vane opening is less than the safety interlock value, and the real-time throat difference fed back at this time does not match the real-time guide vane opening, the DCS control system will not control the air compressor to shut down. Only when the guide vane opening is less than the safety interlock value and the real-time throat difference fed back at this time matches the real-time guide vane opening, the DCS control system will control the air compressor to shut down, avoiding the chain shutdown of the air compressor caused by the failure of a single guide vane position feedback device.

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