Shutdown control device and method for diaphragm compressor

Abstract

The invention discloses a shutdown control device and method for a diaphragm compressor, the shutdown control device is used for controlling a piston not to be located at a piston bottom dead center when the diaphragm compressor is shut down, the shutdown control device comprises a rotating speed measuring assembly and a target area monitoring assembly, and the rotating speed measuring assembly is arranged on a flywheel or on the outer side of the edge of the flywheel; the target area monitoring assembly is arranged on the edge and the outer side of the edge of the flywheel and used for monitoring whether the flywheel enables a piston to stop at a piston bottom dead center or not; when the diaphragm compressor is stopped, the piston is not located at the piston lower dead center, the situation that the symmetric diaphragm compressor is started at the piston lower dead center position is avoided, and manual starting of the diaphragm compressor is avoided.

Description

Technical Field

[0001] This invention relates to the field of compressor shutdown control, and specifically to a shutdown control device and method for a diaphragm compressor. Background Technology

[0002] A diaphragm compressor is a specialized gas compression device that allows only minute leaks or no leaks at all. Based on the distribution of the cylinder centerline, diaphragm compressors are classified into vertical compressors, horizontal compressors, and angled compressors. Diaphragm compressors typically use an electric motor as the prime mover. The motor is equipped with a flexible belt to transmit power, which drives the compressor's pulley or flywheel to rotate, thus rotating the compressor's crankshaft. Similar to other reciprocating compressors, the crankshaft of a diaphragm compressor provides reciprocating motion via a connecting rod mounted on an eccentric shaft (crank). The other end of the connecting rod is connected to a crosshead via a crosshead pin, and the crosshead moves within an intermediate cylinder. A hydraulic piston rod is mounted on the crosshead, and the piston on the piston rod moves within a hydraulic cylinder, sealed with piston rings. The piston causes a fixed volume of hydraulic oil to pulsate back and forth relative to the diaphragm assembly. When the piston moves to its highest position, the distance between the piston and the crankshaft center is the greatest, called top dead center (TDC); when the piston moves downwards from TDC to its lowest position, the distance between the piston and the crankshaft center is the shortest, called bottom dead center (BDC).

[0003] Symmetrical balanced diaphragm compressors are common in diaphragm compressors. These horizontal compressors are characterized by low vibration, light weight, and wide application range. Under the action of reciprocating inertial forces, they achieve dynamic balance, thus reducing vibration. Because the moving parts are in a balanced state, they can rotate at high speeds, and the compressor itself can be miniaturized and made lighter. However, in actual operation, when the piston is at bottom dead center, the motor cannot drive the crankshaft. The flywheel or pulley must be manually cranked to bypass the bottom dead center before the motor can start and drive the crankshaft, which is very inconvenient in actual operation.

[0004] Therefore, in order to avoid the situation where a symmetrical diaphragm compressor needs to be manually started at the bottom dead center of the piston, a shutdown control method for the diaphragm compressor needs to be proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a shutdown control method for a diaphragm compressor to avoid the situation where a symmetrical diaphragm compressor stops at the bottom dead center of the piston and requires manual restart.

[0006] To achieve the above objectives, the present invention proposes a shutdown control device for a diaphragm compressor, used to control the piston from being at the bottom dead center when the diaphragm compressor stops. The device includes a speed measuring component and a target area monitoring component. The speed measuring component is disposed on the flywheel or on the outer edge of the flywheel and is used to measure the speed of the flywheel. The target area monitoring component is disposed on the edge of the flywheel and on the outer edge of the edge and is used to monitor whether the flywheel causes the piston to stop at the bottom dead center.

[0007] Preferably, the speed measurement component includes a speed sensor and a speed measuring gear. The speed sensor is disposed on the outer edge of the flywheel, and the speed measuring gear is disposed on the flywheel. The speed sensor and the speed measuring gear cooperate to measure the speed of the flywheel.

[0008] Preferably, the speed measuring teeth are arranged around the edge of the flywheel.

[0009] Preferably, the target area monitoring component includes an optical sensor and a cursor area. The cursor area is disposed on the flywheel, and the optical sensor is disposed outside the flywheel. The target area monitoring component is positioned to correspond to the bottom dead center of the piston. When the cursor area reaches the monitoring range of the optical sensor, it indicates that the rotation of the flywheel has caused the piston to move to the bottom dead center region of the piston.

[0010] Preferably, the cursor area is located on the edge of the flywheel; the optical sensor is fixed to the chassis of the diaphragm compressor by a bracket.

[0011] A second aspect of the present invention provides a shutdown control method for a diaphragm compressor, wherein the shutdown control device for the diaphragm compressor includes the following steps:

[0012] S1. When the unit starts to shut down, the speed measurement component measures whether the speed of the flywheel is less than A r / min;

[0013] S2. When the flywheel speed is less than A r / min, the optical sensor starts to operate and monitors whether the cursor area is within the monitoring range of the optical sensor.

[0014] S3. When the optical sensor detects that the cursor area is within the monitoring range, control the motor to jog for B seconds to make the cursor area cross the monitoring range of the optical sensor.

[0015] S4. The speed measurement component continuously monitors the speed of the flywheel, and the optical sensor continuously monitors whether the cursor area is within the monitoring range of the optical sensor until the speed of the flywheel becomes 0 r / min.

[0016] Preferably, in step S4, after the motor is jogged, the optical sensor continues to monitor whether the cursor area is within the monitoring range of the optical sensor. If the optical sensor does not detect the cursor area when the speed drops to 0 r / min, it means that the piston has not stopped at the bottom dead center of the piston. If the optical sensor detects a signal when the speed drops to 0 r / min, then steps S3-S4 are repeated until the speed of the flywheel 7 becomes 0 r / min and the optical sensor 9 does not detect a signal.

[0017] Preferably, A is set according to actual operation, and B is set according to motor performance and unit operation.

[0018] Preferably, A r / min is 3 r / min and B seconds is 2 to 3 seconds.

[0019] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0020] This solution discloses a shutdown control device and method for a diaphragm compressor. The shutdown control device includes a speed measuring component and a target area monitoring component. The speed measuring component is disposed on the flywheel or on the outer edge of the flywheel and is used to measure the speed of the flywheel. The target area monitoring component is disposed on the edge of the flywheel and on the outer edge of the edge and is used to monitor whether the flywheel stops the piston at the bottom dead center. This device can control the piston to not be at the bottom dead center when the diaphragm compressor stops, avoiding the starting of a symmetrical diaphragm compressor at the bottom dead center position and avoiding manual starting of the diaphragm compressor.

[0021] This solution has a simple structure, can be effectively applied in practice, reduces difficulties in actual operation, and improves actual work efficiency.

[0022] The apparatus and method described in this solution can also be extended to diaphragm compressors with other structural types that are difficult to start at the bottom dead center, thus having a wide range of applications. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the shutdown control device for the diaphragm compressor of the present invention;

[0024] Figure 2 This is a flowchart of the shutdown control method for the diaphragm compressor of the present invention. Detailed Implementation

[0025] The technical solutions, structural features, achieved objectives, and effects of the present invention will be described in detail below with reference to the accompanying drawings in the embodiments of the present invention.

[0026] It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions. They are only used to facilitate and clarify the purpose of illustrating the embodiments of the present invention, and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationship, or adjustments to the size should still fall within the scope of the technical content disclosed in the present invention, provided that they do not affect the effects and objectives that the present invention can produce.

[0027] It should be noted that, in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only the expressly listed elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0028] This embodiment discloses a shutdown control device for a diaphragm compressor, which controls the flywheel of the diaphragm compressor to not be at the bottom dead center position when the compressor is stopped, so as to avoid the need to manually rotate the flywheel around the bottom dead center when it is used next time.

[0029] Figure 1 This diagram illustrates the structure of a symmetrical diaphragm compressor. It includes two sets of pistons 1, piston rods 2, crossheads 3, connecting rods 4, cranks 5, crankshafts 6, and bearing seats 11 connected sequentially. The bearing seats 11 are mounted on the crankshafts 6. The two sets of components are symmetrically arranged and connected by two cranks 5. The diaphragm compressor also includes a flywheel 7 and a motor (not shown). The flywheel 7 is connected to the crankshaft 6 of one set of components. The motor drives the flywheel 7 to rotate, which in turn drives the crankshaft 6 to rotate. The rotation of the crankshaft 6 drives the cranks 5 connected to it and the cranks 5 on the other set of components to rotate, causing the two connecting rods 4 to reciprocate. Ultimately, this causes the piston 1 to move within a hydraulic cylinder. The piston 1 causes a fixed volume of hydraulic oil to pulsate relative to the diaphragm assembly. When the piston 1 moves to its uppermost position, the distance between the piston 1 and the center of the crankshaft 6 is the greatest; this is the top dead center (TDC). When the piston 1 moves downwards from TDC to its lowermost position, the distance between the piston 1 and the center of the crankshaft 6 is the closest; this is the bottom dead center (BDC). In actual operation, when the motor stops and piston 1 stops at the bottom dead center, the motor cannot drive flywheel 7 and crankshaft 6 when it restarts. The flywheel 7 needs to be manually cranked to bypass the bottom dead center before the motor can be started. The above describes the structure of a symmetrical diaphragm compressor. Similar problems exist in other diaphragm compressors with a bottom dead center.

[0030] To solve the above problems, the shutdown control device for the diaphragm compressor disclosed in this embodiment includes: a speed measuring component, which is disposed on the flywheel 7 or on the outer edge of the flywheel 7, for measuring the speed of the flywheel 7; and a target area monitoring component, which is disposed on the edge of the flywheel 7 and on the outer edge of the edge, for monitoring whether the flywheel 7 stops the piston at the bottom dead center of the piston.

[0031] The rotational speed measurement assembly includes a rotational speed sensor 8 and a speed measuring gear 12. The rotational speed sensor 8 is disposed on the outer edge of the flywheel 7, and the speed measuring gear 12 is disposed on the flywheel 7, for example, it can be disposed around the edge of the flywheel 7. As the flywheel 7 rotates, the rotational speed sensor 8 and the speed measuring gear 12 cooperate to measure the rotational speed of the flywheel 7. In other embodiments, other methods can also be used to measure the rotational speed of the flywheel 7.

[0032] The target area monitoring component includes an optical sensor 9 and a cursor area 10. The cursor area 10 is disposed on the flywheel 7, typically on its edge. The optical sensor 9 is disposed outside the flywheel 7. The target area monitoring component is positioned corresponding to the piston's bottom dead center. When the cursor area 10 reaches the monitoring range of the optical sensor 9, it indicates that the rotation of the flywheel 7 has caused the piston 1 to move to the piston's bottom dead center region. In this embodiment, the optical sensor 9 is fixed to the chassis of the diaphragm compressor by a bracket.

[0033] Different devices have different piston bottom dead center positions, which need to be determined through actual operation.

[0034] Based on the above-mentioned diaphragm compressor shutdown control device, this embodiment also discloses a diaphragm compressor shutdown control method, such as... Figure 2 As shown, it includes the following steps:

[0035] S1. When the unit starts to shut down, the speed measurement component measures whether the speed of the flywheel 7 is less than A r / min;

[0036] The rotational speed of A r / min indicates that the flywheel 7 will stop rotating. The value of A is determined according to the actual operating conditions, and A r / min is generally set to 3 r / min.

[0037] S2. When the rotational speed of flywheel 7 is less than A r / min, optical sensor 9 starts to run and monitors whether cursor area 10 is within the monitoring range of optical sensor 9. When optical sensor 9 detects a signal, it means that cursor area 10 is within the monitoring range of optical sensor 9.

[0038] S3. When the optical sensor 9 detects that the cursor area 10 is within the monitoring range, the motor is controlled to jog for B seconds to make the cursor area 10 cross the monitoring range of the optical sensor 9, that is, to prevent the piston from stopping at the bottom dead center position.

[0039] The value of B is determined based on the motor performance, unit operation, etc. in actual operation. In this embodiment, B seconds is set to 2 to 3 seconds.

[0040] S4. The speed measurement component continuously monitors the speed of the flywheel 7, and the optical sensor 9 continuously monitors whether the cursor area 10 is within the monitoring range of the optical sensor 9 until the speed of the flywheel 7 becomes 0 r / min.

[0041] Specifically, after the motor is jogged, the speed of the flywheel 7 generally does not exceed A r / min. At this time, the optical sensor 9 continues to monitor whether the cursor area 10 is within the monitoring range of the optical sensor 9. If the speed drops to 0 r / min and the optical sensor 9 does not detect a signal, it means that the piston has not stopped at the bottom dead center of the piston. If the speed drops to 0 r / min and the optical sensor 9 detects a signal, it means that the piston has stopped at the bottom dead center of the piston. Then, repeat steps S3-S4, that is, control the motor to jog again for B seconds, and the speed measurement component continues to monitor the speed of the flywheel 7, and the optical sensor 9 continues to monitor whether the cursor area 10 is within the monitoring range of the optical sensor 9, until the speed of the flywheel 7 becomes 0 r / min and the optical sensor 9 does not detect a signal.

[0042] It should be noted that when implementing this method, the specific location and angle of the flywheel 7 corresponding to the bottom dead center of the piston need to be measured during actual operation, and the cursor area 10 and optical sensor 9 need to be set according to the measurement results.

[0043] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A shutdown control device for a diaphragm compressor, used to control the piston from being at bottom dead center when the diaphragm compressor stops, characterized in that, It includes a speed measurement component and a target area monitoring component. The speed measurement component is set on the flywheel or on the outer edge of the flywheel and is used to measure the speed of the flywheel. The target area monitoring component is set on the edge of the flywheel and on the outer edge of the edge and is used to monitor whether the flywheel stops the piston at the bottom dead center of the piston.

2. The shutdown control device for a diaphragm compressor as described in claim 1, characterized in that, The rotational speed measurement component includes a rotational speed sensor and a speed measuring gear. The rotational speed sensor is located on the outer edge of the flywheel, and the speed measuring gear is located on the flywheel. The rotational speed sensor and the speed measuring gear work together to measure the rotational speed of the flywheel.

3. The shutdown control device for a diaphragm compressor as described in claim 2, characterized in that, The speed measuring teeth are arranged around the edge of the flywheel.

4. The shutdown control device for a diaphragm compressor as described in claim 1, characterized in that, The target area monitoring component includes an optical sensor and a cursor area. The cursor area is set on the flywheel, and the optical sensor is set outside the flywheel. The target area monitoring component is positioned to correspond to the bottom dead center of the piston. When the cursor area reaches the monitoring range of the optical sensor, it indicates that the rotation of the flywheel has caused the piston to move to the bottom dead center region.

5. The shutdown control device for a diaphragm compressor as described in claim 4, characterized in that, The cursor area is set on the edge of the flywheel; the optical sensor is fixed to the chassis of the diaphragm compressor by a bracket.

6. A shutdown control method for a diaphragm compressor, employing the shutdown control device for a diaphragm compressor as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1. When the unit starts to shut down, the speed measurement component measures whether the speed of the flywheel is less than Ar / min; S2. When the flywheel speed is less than Ar / min, the optical sensor starts to operate and monitors whether the cursor area is within the monitoring range of the optical sensor. S3. When the optical sensor detects that the cursor area is within the monitoring range, control the motor to jog for B seconds to make the cursor area cross the monitoring range of the optical sensor. S4. The speed measurement component continuously monitors the speed of the flywheel, and the optical sensor continuously monitors whether the cursor area is within the monitoring range of the optical sensor until the speed of the flywheel becomes 0 r / min.

7. The shutdown control method for a diaphragm compressor as described in claim 6, characterized in that, In step S4, after the motor is jogged, the optical sensor continues to monitor whether the cursor area is within the monitoring range of the optical sensor. If the optical sensor does not detect the cursor area when the speed drops to 0 r / min, it means that the piston has not stopped at the bottom dead center of the piston. If the optical sensor detects a signal when the speed drops to 0 r / min, then steps S3-S4 are repeated until the speed of flywheel 7 becomes 0 r / min and the optical sensor 9 does not detect a signal.

8. The shutdown control method for a diaphragm compressor as described in claim 6, characterized in that, A is set according to actual operation, and B is set according to motor performance and unit operation.

9. The shutdown control method for a diaphragm compressor as described in claim 8, characterized in that, Ar / min is 3r / min, B seconds is 2 to 3 seconds.

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