Diaphragm adjusting device of diaphragm compressor under negative pressure air intake

Abstract

The utility model discloses a diaphragm adjusting device of a diaphragm compressor under negative pressure air intake. The diaphragm adjusting device comprises a motion driving assembly, a magnetic adjusting unit, a position detection module, an adjusting module, a power supply module and a change-over switch, the magnetic force adjusting unit comprises a first magnetic force assembly and a second magnetic force assembly which are respectively connected with the first branch circuit and the second branch circuit of the power supply module through the adjusting module and are used for applying directional adsorption force to the diaphragm; the position detection module comprises a first detection unit and a second detection unit which are fixed to the surface of the fixing support and the surface of the motion driving assembly respectively, and the distance between the first detection unit and the second detection unit is changed along with reciprocating motion of the motion driving assembly so as to control on-off of the first branch and the second branch. The change-over switch is controlled by the magnetic force adjusting unit and used for switching the power supply state of the first branch circuit and the power supply state of the second branch circuit, so that the first magnetic force assembly is powered on to assist the diaphragm in resetting when the motion driving assembly reaches the first position.

Description

Technical Field

[0001] This utility model relates to the field of compressor technology, specifically to a diaphragm adjustment device for a diaphragm compressor with negative pressure intake. Background Technology

[0002] A diaphragm compressor is a positive displacement compressor. Unlike traditional reciprocating piston compressors that compress gas directly through a piston, a diaphragm compressor compresses gas by having a piston push hydraulic oil, which in turn drives a diaphragm to reciprocate. Because the diaphragm divides the compression chamber into a gas chamber and an oil chamber, the gas does not come into direct contact with the oil. Therefore, it has advantages such as high purity and good sealing. In addition, it has advantages such as low vibration, low noise, small clearance volume, and stable operation, so it is widely used in hydrogen refueling stations.

[0003] The structure of existing diaphragm compressors is as follows: Figure 1 As shown, the assembly includes a diaphragm head assembly 01 (including a gas-side diaphragm head 01A and an oil-side diaphragm head 01B), a piston assembly 02, a crosshead assembly 03, a chassis assembly 04 (including a central body 04A and a crankcase 04B), a crankshaft connecting rod assembly 05, and a plunger pump assembly 06. First, the gas-side and oil-side diaphragm heads are connected to form the diaphragm head assembly 01 using studs. A metal diaphragm is placed between the gas-side and oil-side diaphragm heads and pressed tightly by the preload of the studs. The central body and crankcase are connected to the chassis assembly 04 using studs. Then, the diaphragm head assembly 01 and chassis assembly 04 are connected by threads. The crosshead assembly 03 is connected to the piston assembly 02 and the crankshaft connecting rod assembly 05 by threads. The crankshaft connecting rod assembly 05 is placed inside the crankcase. The crosshead assembly 03 is placed inside the central body slideway. The plunger pump assembly 06 is attached to the non-flywheel side of the crankshaft, drawing hydraulic oil from the crankcase and replenishing the oil-side diaphragm chamber. The motor drives the crank-connecting rod mechanism, which in turn drives the piston to reciprocate. When the piston reaches the top dead center, it pushes the hydraulic oil, further driving the diaphragm to deform upwards. The diaphragm eventually deforms and fits against the wall of the gas chamber, achieving compression and exhaust of the gas inside the chamber. When the piston moves downwards, the oil pressure decreases until it falls below the intake pressure. The intake pressure inside the gas chamber then drives the diaphragm to deform back into the oil chamber until the piston reaches the bottom dead center position.

[0004] During negative pressure intake, the diaphragm is subjected to both negative and normal hydraulic pressure (since the hydraulic oil is unsealed and constantly connected to the outside, it can only drop to atmospheric pressure at its lowest). At the end of intake, the diaphragm cannot return to its equilibrium position and, under the combined effect of its own rebound force and the pressure difference between the two sides, deflects towards the air side. Furthermore, during the process of the diaphragm adhering to the air side, due to the diaphragm's own characteristics and the multiple influences of the air distribution plate's intake and exhaust ports, the diaphragm cannot completely adhere. These factors indirectly lead to a reduction in the air chamber volume, resulting in a significant decrease in volumetric efficiency. (Xue Jiang) [1]Adjusting the oil chamber pressure by replenishing oil allows the diaphragm to spring back to its original position. However, lowering the oil pressure below atmospheric pressure causes a large number of air bubbles to precipitate in the hydraulic oil within the chamber. If these bubbles are not removed in time, diaphragm cavitation may occur. This invention designs a diaphragm adjustment device for a diaphragm compressor under negative pressure intake. By using the attraction force of an electromagnet to adjust the diaphragm position, the fit is improved, thereby increasing the air chamber volume and the intake volume, solving the problem of low actual volumetric efficiency under negative pressure intake.

[0005] Compared to atmospheric pressure intake, the efficiency of a diaphragm compressor drops sharply under negative pressure intake due to the difficulty in diaphragm separation and repositioning. The aforementioned diaphragm compressor lacks a corresponding device to improve its volumetric efficiency under negative pressure intake conditions, and adjusting the oil supply cannot eliminate the negative impact of diaphragm separation. Utility Model Content

[0006] The purpose of this invention is to provide a diaphragm adjustment device for a diaphragm compressor under negative pressure intake, in order to solve the technical problems existing in the background art.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A diaphragm adjustment device for a negative pressure intake diaphragm compressor includes:

[0009] Motion drive components, magnetic adjustment unit, position detection module, adjustment module, power supply module, and switch;

[0010] The magnetic adjustment unit includes a first magnetic component and a second magnetic component, which are respectively connected to the first branch and the second branch of the power supply module through the adjustment module, and are used to apply directional adsorption force to the diaphragm.

[0011] The position detection module includes a first detection unit and a second detection unit, which are respectively fixed to the fixed bracket and the surface of the motion drive component, and change the spacing with the reciprocating motion of the motion drive component to control the on / off state of the first branch and the second branch.

[0012] The switching switch is controlled by the magnetic adjustment unit and is used to switch the power supply status of the first branch and the second branch, so that the first magnetic component is energized when the motion drive component reaches the first position to assist the diaphragm in resetting, and the second magnetic component is energized when the motion drive component reaches the second position to eliminate local bulging during diaphragm adhesion.

[0013] In some embodiments, the motion drive assembly includes a crosshead assembly and a piston assembly, the crosshead assembly being rigidly connected to the piston assembly, and the piston assembly driving the crosshead assembly to reciprocate via a crankshaft connecting rod mechanism.

[0014] In some embodiments, the first magnetic component is an electromagnet disposed in the center of the valve plate, and the second magnetic component is an electromagnet disposed in the poorly fitting area inside the valve plate; the electromagnet is connected in series with the first branch of the power supply module through a sliding rheostat, and the electromagnet is connected in series with the second branch of the power supply module through a sliding rheostat.

[0015] In some embodiments, the position detection module includes:

[0016] First detection unit: a capacitor assembly consisting of a left plate fixed to the inner wall of the middle body and a right plate fixed to the surface of the crosshead assembly;

[0017] The second detection unit is a capacitor assembly consisting of a right side plate fixed to the inner wall of the middle body and a left side plate fixed to the surface of the crosshead assembly.

[0018] When the crosshead assembly moves to the top dead center, the capacitor assembly activates the first branch; when it moves to the bottom dead center, the capacitor assembly activates the second branch.

[0019] In some embodiments, the adjustment module includes:

[0020] First adjustment unit: sliding rheostat, used to adjust the adsorption force of the first magnetic component according to the difference between the intake pressure and the oil pressure and the diaphragm area;

[0021] The second adjustment unit is a sliding rheostat, used to dynamically adjust the attraction force of the second magnetic component to eliminate local bulges.

[0022] In some embodiments, the switching switch is a ferromagnetic switch, and its contact switching is controlled by an electromagnet connected in series with the capacitor assembly; when the first branch is closed, the electromagnet attracts the ferromagnetic switch to contact I; when the second branch is closed, the electromagnet attracts the ferromagnetic switch to contact II.

[0023] In some embodiments, the diaphragm is made of metal and its magnetic permeability is coordinated with the magnetic field direction of the first magnetic component and the second magnetic component; the gas distribution plate is provided with intake and exhaust holes, and the oil distribution plate contacts the oil side surface of the diaphragm to adjust the oil chamber pressure.

[0024] In some embodiments, the fixed bracket is a middle body, which is fixed to the body assembly by studs, and the distance between the left and right plates of the capacitor assembly changes periodically with the reciprocating motion of the crosshead assembly.

[0025] The beneficial effects that the negative pressure intake diaphragm compressor diaphragm adjustment device disclosed in this application may bring include, but are not limited to:

[0026] (1) When the negative pressure intake of the diaphragm compressor ends, the diaphragm cannot return to the equilibrium position, resulting in a decrease in the intake volume. This invention assists the diaphragm to rebound through electromagnetic adsorption, thereby increasing the volume of the air chamber, improving the intake volume, and thus improving the volumetric efficiency of the compressor. This invention avoids the problem of negative pressure cavitation caused by directly adjusting the oil pressure in the oil chamber, which leads to the precipitation of air bubbles.

[0027] (2) When the diaphragm of the diaphragm compressor is attached to the gas side, due to the characteristics of the diaphragm itself and the influence of the suction and exhaust holes of the gas distribution plate, the diaphragm will have local bulges. An electromagnet is installed at the position of the gas distribution plate corresponding to the bulge to eliminate this adverse effect, which also increases the gas chamber volume and is conducive to improving volumetric efficiency.

[0028] (3) The action time of the electromagnet of this utility model is directly determined by the movement of the crosshead, so the adjustment is precise. Even under harsh working conditions, it has good follow-up performance and is suitable for different working conditions. The magnitude of the adsorption force can be adjusted to cope with different negative pressure scenarios. Attached Figure Description

[0029] Figure 1 : Schematic diagram of the overall structure of an existing diaphragm compressor.

[0030] Figure 2 Diagram of the diaphragm adjustment device.

[0031] Figure 3 : Capacitor control circuit diagram. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0033] Conversely, this application covers any substitutions, modifications, equivalent methods, and schemes made within the spirit and scope of this application as defined in the claims. Furthermore, to provide the public with a better understanding of this application, certain specific details are described in detail below. However, this application can be fully understood by those skilled in the art even without these detailed descriptions.

[0034] like Figure 1-3 As shown, an electromagnet is used to adjust the position of a diaphragm. This structure can squeeze out the air pocket in the middle of the diaphragm and adjust the position of the diaphragm, thereby increasing the air intake volume and thus improving the volumetric efficiency.

[0035] like Figure 2To achieve the above objectives, this utility model provides the following technical solution: a diaphragm compressor diaphragm adjustment device, comprising a piston assembly 02, a crosshead assembly 03, a gas distribution plate 07, electromagnets 08A and 08B, a diaphragm 09, an electromagnet 10, an oil distribution plate 11, a capacitor assembly 12 (including capacitors 12A (left side plate 12AA, right side plate 12AB) and 12B (left side plate 12BA, right side plate 12BB)), a power supply U1, a power supply U2, a sliding rheostat R1, a sliding rheostat R2, a capacitor assembly 13 (including capacitors 13A (left side plate 13AA, right side plate 13AB) and 13B (left side plate 13BA, right side plate 13BB)), an electromagnet 14, an electromagnet 15, and a switch S.

[0036] Electromagnets 08A and 08B are both located inside the gas distribution plate 07, corresponding to areas where the diaphragm adhesion is poor, and are connected in series. Electromagnet 10 is located in the center of the oil distribution plate 11 and is connected in parallel with 08A and 08B. The diaphragm 09 is a metal diaphragm. The switch S is made of ferromagnetic material. The two left-side plates 12AA and 12BA of the capacitor assembly 12 are fixed inside the middle body 04A, near the upper stop position of the crosshead 03, and the two right-side plates 12AB and 12BB are fixed on the left side of the crosshead and insulated from the crosshead. The two right-side plates 13AB and 13BB of capacitor assembly 13 are fixed inside the middle body 04A and close to the lower stop position of crosshead 03. The two left-side plates 13AA and 13BA are fixed on the right side of crosshead and insulated from crosshead. The two capacitor assemblies are alternately energized as crosshead moves, controlling electromagnets 14 and 15 to attract switches S to control the two branches of U1 circuit. The power supplies U1 and U2 are used to supply power to the electromagnet circuit. The sliding rheostats are connected in series with 08A, 08B and 10 to control the magnitude of the electromagnetic force.

[0037] like Figure 3When piston assembly 02 moves to top dead center, 12AB and 12BB also move to top dead center along with crosshead 03. The distance between the four capacitor plates of capacitor element 12 is controlled so that when two capacitor plates 12AB and 12BB are close to the top dead center position, they form an AC current path with 12AA and 12BA respectively. Electromagnet 14 will be energized, and the attraction switch S will be switched to contact I. At this time, electromagnet 10 is energized, and a force pointing towards the oil side is applied to the diaphragm. The magnitude of this force can be controlled by sliding rheostat R1. Ignoring the diaphragm's own rebound force (too small), the magnitude of the force is taken as (normal pressure, i.e., minimum oil pressure - intake pressure) × diaphragm area. Switch S remains connected to contact I until the piston reaches the bottom dead center. Capacitors 13AA and 13BA move with the crosshead to form an AC path with 13AB and 13BB. Electromagnet 15 is energized, attracting switch S to contact II and disconnecting it from contact I. Electromagnet 10 is de-energized. At this time, electromagnets 08A and 08B are energized, applying a force towards the gas side to the diaphragm. Ideally, the diaphragm and the gas side will be completely in contact. Adjustment is made by sliding rheostat R2 to eliminate bulges caused by poor contact and to avoid excessive force impacting the gas distribution plate 07 on the gas side.

[0038] Electromagnets 10, 08A, and 08B work alternately with the piston movement. At the end of the intake process, they assist the diaphragm to return to the middle position and eliminate air pockets caused by poor adhesion when the diaphragm is in contact with the air side. Both improvements increase the volume of the air chamber, increase the intake volume, and thus improve the volumetric efficiency.

[0039] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A negative pressure inlet diaphragm compressor membrane adjustment device, characterized by, The device comprises a motion driving assembly, a magnetic force adjusting unit, a position detecting module, an adjusting module, a power supply module and a switching switch. The magnetic force adjusting unit comprises a first magnetic force assembly and a second magnetic force assembly, which are connected to the first branch and the second branch of the power supply module through the adjusting module, respectively, for applying directional adsorption force to the diaphragm. The position detecting module comprises a first detecting unit and a second detecting unit, which are fixed to the fixed support and the surface of the motion driving assembly, respectively, and change the distance with the reciprocating motion of the motion driving assembly to control the on-off of the first branch and the second branch. The switching switch is controlled by the magnetic force adjusting unit to switch the power supply state of the first branch and the second branch, so that the first magnetic force assembly is powered on to assist the diaphragm to reset when the motion driving assembly reaches the first position, and the second magnetic force assembly is powered on to eliminate the local bulge of the diaphragm when it is attached.

2. The diaphragm adjusting device of the negative pressure intake lower diaphragm compressor according to claim 1, wherein the motion driving assembly comprises a crosshead assembly and a piston assembly, the crosshead assembly is rigidly connected to the piston assembly, and the piston assembly drives the crosshead assembly to make reciprocating motion through a crankshaft connecting rod mechanism.

3. The diaphragm adjusting device of the negative pressure intake lower diaphragm compressor according to claim 1, wherein the first magnetic force assembly is an electromagnet arranged at the center of the oil distribution plate, the second magnetic force assembly is an electromagnet arranged at the area of poor adhesion inside the gas distribution plate, the electromagnet is connected in series with the first branch of the power supply module through a sliding rheostat R1, and the electromagnet is connected in series with the second branch of the power supply module through a sliding rheostat R2.

4. The diaphragm adjusting device of the negative pressure intake lower diaphragm compressor according to claim 1, wherein the position detecting module comprises: a first detecting unit: a capacitor assembly composed of a left side piece fixed to the inner wall of the middle body and a right side piece fixed to the surface of the crosshead assembly; a second detecting unit: a capacitor assembly composed of a right side piece fixed to the inner wall of the middle body and a left side piece fixed to the surface of the crosshead assembly; When the crosshead assembly moves to the top dead center, the capacitor assembly turns on the first branch; when it moves to the bottom dead center, the capacitor assembly turns on the second branch.

5. The diaphragm adjusting device of the negative pressure intake lower diaphragm compressor according to claim 1, wherein the adjusting module comprises: a first adjusting unit: a sliding rheostat R1, which is used to adjust the adsorption force of the first magnetic force assembly according to the difference between the intake pressure and the oil pressure and the area of the diaphragm; a second adjusting unit: a sliding rheostat R2, which is used to dynamically adjust the adsorption force of the second magnetic force assembly to eliminate the local bulge.

6. The diaphragm adjusting device of the negative pressure intake lower diaphragm compressor according to claim 4, wherein ​ ​ ​ ​ ​ The switch is a ferromagnetic switch S, and the contact switching is controlled by the electromagnetic attraction of an electromagnet connected in series with the capacitor assembly; when the first branch is turned on, the electromagnet attracts the ferromagnetic switch S to contact I; when the second branch is turned on, the electromagnet attracts the ferromagnetic switch S to contact II.

7. The negative pressure intake lower diaphragm compressor membrane adjusting device according to claim 3, wherein: The membrane is made of metal, and the magnetic permeability thereof is coordinated with the magnetic field direction of the first magnetic force assembly and the second magnetic force assembly; the gas distribution disc is provided with suction and exhaust holes, and the oil distribution disc is in contact with the oil side surface of the membrane to adjust the oil cavity pressure.

8. The negative pressure intake lower diaphragm compressor membrane adjusting device according to claim 6, wherein: The fixed support is a middle body, the middle body is fixed with the machine body assembly through a stud, and the left side piece and the right side piece of the capacitor assembly periodically change in distance with the reciprocating motion of the cross head assembly.

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