System and method for diaphragm compressor flow regulation and reduction of hydraulic oil gas content

Abstract

The application relates to a method and system for regulating the flow of a diaphragm compressor and reducing the gas content of hydraulic oil, and designs a system and method for regulating the flow of a diaphragm compressor and reducing the gas content of hydraulic oil, which controls the actual flow of the diaphragm compressor and the oil pressure in the cylinder of the diaphragm compressor in real time through a control unit, and then controls the opening of an electrical proportional valve in real time, so as to realize the regulation and control of the inlet pressure of a high-pressure gas cavity I of a flow regulator, and then control the volume of hydraulic oil flowing into an oil-side diaphragm cavity in an oil cavity III in the flow regulator of the compressor in the expansion and air suction stage, and make the hydraulic oil flowing into the oil-side diaphragm cavity of the diaphragm compressor flow into the oil cavity III again through the exhaust pressure of the high-pressure gas cavity set by the electrical proportional valve in the compression and exhaust stage, so as to complete the whole flow regulation process. Meanwhile, the device is ingeniously designed, and the non-return property of a one-way valve can realize the reduction of the gas content of the hydraulic oil while regulating the flow.

Description

Technical Field

[0001] This invention belongs to the field of diaphragm compressor technology, and specifically relates to a system and method for regulating the flow rate of a diaphragm compressor and reducing the gas content of hydraulic oil. Background Technology

[0002] Hydrogen refueling stations play a crucial role in hydrogen energy applications. They provide hydrogen efficiently and cleanly, support rapid refueling of hydrogen fuel cell vehicles, promote the widespread use of renewable energy, and contribute to environmental protection.

[0003] Diaphragm compressors offer highly efficient and stable hydrogen compression capabilities, operating under high pressure and preventing leaks. Their oil-free design ensures hydrogen purity, avoiding oil contamination and related safety risks. The diaphragm structure provides excellent sealing, reducing the risk of hydrogen leakage. Simultaneously, their compression process is highly efficient and energy-saving, adapting to the high permeability of hydrogen, and is widely used in hydrogen refueling stations, chemical and medical gas applications. Their simple structure, strong shock resistance, and ease of maintenance provide reliable support for the safe storage and transportation of high-purity gases. Therefore, diaphragm compressors, due to their high efficiency, safety, and durability, are widely used in hydrogen refueling stations to ensure a stable hydrogen supply.

[0004] However, hydrogen refueling stations operate under typical variable conditions. Under these conditions, the unloading of hydrogen from the long-tube trailer requires a two-stage diaphragm compressor. The pressure ratio of the first stage of this two-stage diaphragm compressor is only related to the structural parameters of the first and second stages. As the hydrogen pressure inside the trailer decreases, the pressure in the hydrogen storage tank at the refueling station increases, causing a significant change in the pressure ratio of the second stage. This results in an unreasonable pressure ratio distribution throughout the entire diaphragm compressor system, leading to energy waste and hindering the efficient and stable operation of the compressor. Although adjusting the flow rate of a particular stage of the diaphragm compressor can reallocate the pressure ratios of the first and second stages for stable compressor operation, the hydraulic oil inevitably comes into contact with air in the housing and intermediate body during its flow from the overflow valve to the intermediate body and then through the crankcase to the oil tank. This results in the presence of a certain amount of gas in the hydraulic oil. When the hydraulic oil contains gas, the bubbles expand or compress with changes in hydraulic oil pressure, and may even rupture, causing system pressure fluctuations or vibrations. This, in turn, exacerbates diaphragm wear and may even lead to cracks, ruptures, or fatigue damage. This can affect the stability and safety of the equipment.

[0005] To improve equipment stability and safety, the flow rate of diaphragm compressors is currently mainly controlled through variable speed regulation and bypass regulation, while dissolved gases in hydraulic oil are removed using heating degassing and vacuum degassing methods. However, variable speed regulation in diaphragm compressor flow control has a drawback: its adjustable range is narrow, typically with a minimum frequency of 30Hz, meaning flow regulation can only be performed between 60% and 100%. Simultaneously, insufficient lubrication of driven components during low-speed compressor operation can lead to increased wear and shorten compressor lifespan. Bypass regulation results in some compressed gas from the compressor not being fully utilized, instead flowing directly back to the inlet. This leads to inefficient use of compressor energy, reduced overall system efficiency, and increased overall energy consumption. Furthermore, the direct return of bypass gas to the compressor inlet during bypass regulation may cause an increase in inlet temperature, adversely affecting compressor performance. The disadvantage of heating degassing for removing dissolved gases from hydraulic oil is that diaphragm compressors operating in hydrogen refueling stations must strictly adhere to station safety requirements and cannot use high temperatures to heat the hydraulic oil in the oil chamber to remove dissolved gases. The disadvantages of vacuum degassing, which uses a vacuum pump, are that it requires the purchase of a high-performance vacuum pump, resulting in a high equipment investment, and regular maintenance, which increases operating costs. Furthermore, operating a vacuum system consumes a significant amount of energy, especially when processing large quantities of oil, further increasing operating costs.

[0006] Therefore, under the premise of reducing energy consumption, it is essential to design a system and method to ensure that the diaphragm compressor can maintain stable, efficient and safe operation under varying operating conditions at hydrogen refueling stations. Summary of the Invention

[0007] To address the shortcomings of the existing technology, the purpose of this invention is to provide a system and method for regulating the flow rate of a diaphragm compressor and reducing the gas content of hydraulic oil. This system enables stepless regulation of the diaphragm compressor flow rate and removes dissolved air bubbles from the hydraulic oil using a vacuum degassing method, thus ensuring the safe and stable operation of the diaphragm compressor.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] This invention provides a system for regulating the flow rate of a diaphragm compressor and reducing the gas content of hydraulic oil, comprising:

[0010] A flow regulator includes a double-acting piston assembly and a gas chamber housing and an oil chamber housing arranged from top to bottom. The double-acting piston assembly has two piston parts, which are respectively located in the gas chamber housing and the oil chamber housing. This allows the gas chamber housing to be divided from top to bottom into a high-pressure gas chamber I and a low-pressure gas chamber II, while the oil chamber housing is also divided from top to bottom into an oil chamber III and a chamber IV. The high-pressure gas chamber I is equipped with an exhaust valve and a first intake valve for adjusting the pressure of the high-pressure gas chamber I. Both the exhaust valve and the first intake valve are connected to the air delivery unit through an electro-proportional valve. The oil chamber III is connected to the oil-side diaphragm chamber of the diaphragm compressor through a pipeline with a control valve. The chamber IV is connected to an intake pipe and an exhaust pipe. Both the exhaust pipe and the intake pipe are equipped with a one-way valve, and the intake pipe is connected to the crankcase of the diaphragm compressor.

[0011] A flow sensor is used to measure the flow rate in the external exhaust pipe of a diaphragm compressor.

[0012] An oil pressure sensor, connected to the oil-side diaphragm chamber of the diaphragm compressor, is used to monitor the pressure in the oil-side diaphragm chamber of the diaphragm compressor during operation.

[0013] The control unit is connected to a flow sensor, an oil pressure sensor, and two electro-proportional valves. The control unit is used to adjust the opening degree of the two electro-proportional valves based on the detection results of the flow sensor and the oil pressure sensor.

[0014] Preferably, the low-pressure air chamber II is further provided with a second intake valve that communicates with the low-pressure air chamber II.

[0015] Preferably, before the flow regulator is connected to the diaphragm compressor, the height between the top surface of the piston portion in chamber IV and the oil chamber housing is 1 mm to 3 mm.

[0016] Preferably, the double-acting piston assembly includes a piston rod, a piston portion disposed in the gas chamber housing is a gas chamber piston, and a piston portion disposed in the oil chamber housing is an oil chamber piston. The piston rod vertically penetrates the gas chamber housing and the oil chamber housing respectively, and is connected to the gas chamber piston and the oil chamber piston respectively. The piston rod is sealed to the gas chamber housing and the oil chamber housing by a first sealing element, and the oil chamber piston is sealed to the oil chamber housing and the gas chamber piston is sealed to the gas chamber housing by a second sealing element.

[0017] Preferably, the piston rod is provided with scale lines.

[0018] Methods for regulating the flow rate of a diaphragm compressor and reducing the air content of the hydraulic oil include the following steps:

[0019] Before connecting the flow regulator to the diaphragm compressor system, gas and hydraulic oil need to be stored in the high-pressure gas chamber I, low-pressure gas chamber II, and oil chamber III of the flow regulator.

[0020] Then open the control valve to put the entire system into operation;

[0021] When the diaphragm compressor is in the expansion and intake state, the control unit obtains the flow rate to be regulated based on the flow rate measurement value and the flow rate set value. Then, the control unit processes and analyzes the obtained oil pressure measurement value to obtain the hydraulic oil pressure at the end of the intake of the diaphragm compressor under the working state. The control unit adjusts the intake pressure of the high-pressure air chamber I by adjusting the opening of the electro-proportional valve, and then adjusts the air pressure of the low-pressure air chamber II at the end of the intake. The piston located in the air chamber housing moves downward under the action of the high-pressure gas in the high-pressure air chamber I, thereby controlling the volume of hydraulic oil in the oil chamber III entering the oil side diaphragm chamber of the diaphragm compressor and increasing the volume of chamber IV, thus reducing the pressure. This achieves the regulation of the diaphragm compressor flow rate while allowing the gas in the crankcase to flow into the chamber IV with a sudden pressure drop through the one-way valve, thus evacuating the crankcase.

[0022] During the compression and discharge phase of the diaphragm compressor, the hydraulic oil pressure in the diaphragm compressor continuously increases, pushing the piston located in the oil chamber housing upward. This causes the gas pressure in high-pressure gas chamber I to continuously rise. When the gas pressure in high-pressure gas chamber I reaches the discharge pressure set by the electro-proportional valve, it is discharged through the discharge valve. At the same time, the hydraulic oil sent into the oil-side diaphragm chamber of the diaphragm compressor in oil chamber III flows back into oil chamber III in equal volume. The volume of chamber IV decreases, so that the gas pressure in chamber IV rises to a level greater than atmospheric pressure and is discharged.

[0023] Preferably, the algorithm for precise flow control of the diaphragm compressor in the control unit is as follows:

[0024] To obtain the relationship between the adjustable flow rate of the diaphragm compressor and the volume change of oil chamber III during the working cycle:

[0025] Δq v =Δv oil λ T λ p λ v-e n;

[0026] Where Δv oil λ is the volume of hydraulic oil entering the oil-side diaphragm chamber from oil chamber III at the end of the diaphragm compressor's suction cycle; n is the diaphragm compressor's rotational speed; λ T λ is the temperature coefficient. p λ is the pressure coefficient. v-e Δq is the expansion coefficient of the high-pressure gas inside the clearance volume. v The adjustable flow rate of the diaphragm compressor during the working cycle;

[0027] The relationship between the volume change of oil chamber III and the gas pressure in low-pressure gas chamber II is obtained:

[0028]

[0029] Where v o p1 is the design volume of low-pressure chamber II under the initial state, p0 is the gas pressure in low-pressure chamber II when the diaphragm compressor finishes suction, and m is the process index.

[0030] To obtain the relationship between the gas pressure in the low-pressure chamber II at the end of the suction cycle of the diaphragm compressor, the suction pressure in the high-pressure chamber I, and the hydraulic oil pressure at the end of the suction cycle:

[0031]

[0032] Where p in p is the intake pressure of high-pressure air chamber I. oil S is the pressure of the hydraulic oil in oil chamber III at the end of the intake phase. gas S is the area of ​​the upper surface of the gas chamber piston. oil Let be the area of ​​the lower surface of the piston in the oil chamber, m be the mass of the double-acting piston system, g be the acceleration due to gravity, and p1 be the pressure of the gas in the low-pressure chamber II at the end of the suction cycle of the diaphragm compressor.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] This invention utilizes the law of coordinated change in oil and gas pressure in diaphragm compressors and the unique oil replenishment and overflow mechanism of diaphragm compressors to design a system for regulating the flow rate of diaphragm compressors and reducing the gas content of hydraulic oil. The control unit measures and controls the actual flow rate of the diaphragm compressor's external exhaust pipe and the oil pressure inside the compressor cylinder in real time, thereby controlling the opening of the electro-proportional valve in real time. This regulates the intake pressure of the high-pressure chamber I of the flow regulator, thus controlling the volume of hydraulic oil flowing from the flow regulator's internal oil chamber III into the oil-side diaphragm chamber of the diaphragm compressor during the expansion and intake phases. During the compression and exhaust phases, the pre-set exhaust pressure of the high-pressure chamber via the electro-proportional valve causes the hydraulic oil entering the oil-side diaphragm chamber of the diaphragm compressor to flow back into oil chamber III, completing the entire flow regulation process. Simultaneously, the ingenious design of this device and the check valve's check function allow for the reduction of hydraulic oil gas content while regulating flow rate.

[0035] This invention features a simple structure and low manufacturing cost, exhibiting excellent performance and high operability during flow regulation. It not only provides excellent flow regulation but also functions to remove dissolved air bubbles from hydraulic oil through vacuuming, making it a reliable, multi-functional device. Flow regulation does not affect system stability or negatively impact compressor lifespan. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the flow regulator of the present invention.

[0037] Figure 2 This is a system diagram of a diaphragm compressor for flow regulation and reducing the gas content of hydraulic oil according to the present invention.

[0038] Figure Labels

[0039] 01. Air chamber housing; 02. Air chamber piston; 03. Piston rod; 04. First intake valve; 05. Exhaust valve; 06. Air chamber end cap; 07. Oil chamber housing; 08. Oil chamber end cap; 09. Oil chamber piston; 1. Diaphragm compressor gas-side diaphragm head; 2. Diaphragm compressor exhaust valve; 3. Diaphragm compressor intake valve; 4. Gas distribution plate; 5. Diaphragm; 6. Oil distribution plate; 7. Diaphragm compressor oil-side diaphragm head; 8. Diaphragm compressor gas-side diaphragm chamber; 9. Diaphragm compressor oil-side diaphragm chamber; 10. Electro-proportional valve; 11. Check valve; 12. Flow sensor; 13. Oil pressure sensor; 14. Control valve; 1A. Second seal; 1B. First seal. Detailed Implementation

[0040] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods.

[0041] The inventors discovered that the hydraulic oil pressure and the compressed gas pressure change synchronously during the operation of the diaphragm compressor. Specifically, the oil pressure decreases in sync with the gas pressure during expansion, and increases synchronously with the gas pressure during compression. Furthermore, the diaphragm compressor replenishes oil during the intake phase and overflows oil during the exhaust phase. Simultaneously, utilizing the unique geometry of the device and the check valve's non-return property, dissolved gases in the hydraulic oil are removed using a vacuum degassing method, making it a novel, multi-functional device.

[0042] In view of this, the present invention provides a system and method for regulating the flow rate of a diaphragm compressor and reducing the gas content of hydraulic oil, thereby achieving stepless regulation of the diaphragm compressor flow rate and removing dissolved air bubbles from the hydraulic oil using a vacuum degassing method, thus ensuring the safe and stable operation of the diaphragm compressor.

[0043] like Figures 1-2 As shown, the system for regulating the flow rate of a diaphragm compressor and reducing the gas content of hydraulic oil provided by the present invention includes:

[0044] The flow regulator includes a double-acting piston assembly and a gas chamber housing 01 and an oil chamber housing 07 arranged from top to bottom. The double-acting piston assembly has two piston parts, which are respectively located in the gas chamber housing 01 and the oil chamber housing 07. This allows the gas chamber housing 01 to be divided into a high-pressure gas chamber I and a low-pressure gas chamber II from top to bottom, while also dividing the oil chamber housing 07 into an oil chamber III and a chamber IV from top to bottom. The high-pressure gas chamber I is equipped with an exhaust valve 05 and a first intake valve 04 for adjusting the pressure of the high-pressure gas chamber I. Both the exhaust valve 05 and the first intake valve 04 are connected to the air delivery unit through an electro-proportional valve 10. The oil chamber III is connected to the oil-side diaphragm chamber 9 of the diaphragm compressor through a pipeline. A control valve 14 is provided on the pipeline. The chamber IV is connected to an intake pipe and an exhaust pipe. Both the exhaust pipe and the intake pipe are equipped with a one-way valve 11, and the intake pipe is connected to the crankcase of the diaphragm compressor.

[0045] Flow sensor 12 is used to measure the flow rate of the external exhaust pipe of the diaphragm compressor;

[0046] The oil pressure sensor 13 is connected to the oil-side diaphragm chamber 9 of the diaphragm compressor and is used to monitor the pressure of the oil-side diaphragm chamber 9 of the diaphragm compressor under working conditions.

[0047] The control unit is connected to the flow sensor 12, the oil pressure sensor 13, and two electro-proportional valves 10. The control unit is used to adjust the opening degree of the two electro-proportional valves 10 according to the detection results of the flow sensor 12 and the oil pressure sensor 13.

[0048] When the diaphragm compressor is in expansion and intake states, the control unit receives the flow rate and oil pressure signals of the diaphragm compressor during operation. Simultaneously, it obtains the required flow rate based on the set flow rate and measured flow rate. The control system then processes and analyzes the measured hydraulic oil pressure to obtain the hydraulic oil pressure at the end of the intake phase. The control unit adjusts the intake pressure of the high-pressure chamber I by regulating the opening of the electro-proportional valve 10, thereby regulating the pressure of the low-pressure chamber II at the end of the intake phase. The piston located within the chamber housing 01 moves downwards under the influence of the high-pressure gas in the high-pressure chamber I, controlling the volume of hydraulic oil entering the diaphragm chamber 9 of the diaphragm compressor from the oil chamber III. This increases the volume of chamber IV and reduces its pressure, thereby regulating the flow rate of the diaphragm compressor while simultaneously allowing gas from the crankcase to flow through the check valve 11 into the chamber IV, where the pressure drops sharply, thus evacuating the crankcase.

[0049] When the diaphragm compressor is in the compression and exhaust phase, the hydraulic oil pressure in the diaphragm compressor continuously increases, pushing the piston located in the oil chamber housing 07 to move upward, causing the gas pressure in the high-pressure gas chamber I to continuously rise. When the gas pressure in the high-pressure gas chamber I reaches the exhaust pressure set by the electro-proportional valve 10, it is discharged through the exhaust valve 05. The hydraulic oil sent into the oil side diaphragm chamber 9 of the diaphragm compressor in the oil chamber III flows back into the oil chamber III in equal volume. The volume of the chamber IV becomes smaller, so that the gas pressure in the chamber IV rises to a level greater than atmospheric pressure and is discharged.

[0050] By using a double-acting piston assembly to move downwards under the action of high-pressure gas in high-pressure chamber I, the volume of hydraulic oil in oil chamber III entering the diaphragm chamber 9 of the diaphragm compressor and the volume of chamber IV are controlled. This allows for the regulation of the diaphragm compressor flow rate while simultaneously allowing gas in the crankcase to flow into the chamber IV, where the pressure drops sharply, through check valve 11.

[0051] The diaphragm compressor has a diaphragm compressor gas-side diaphragm head 1, a diaphragm compressor exhaust valve 2, a diaphragm compressor intake valve 3, an air distribution plate 4, a diaphragm 5, an oil distribution plate 6, a diaphragm compressor oil-side diaphragm head 7, a diaphragm compressor gas-side diaphragm chamber 8, and a diaphragm compressor oil-side diaphragm chamber 9.

[0052] like Figure 1 As shown, a flow regulator specifically comprises a gas chamber housing 01, a gas chamber piston 02, a double-acting graduated piston rod 03, a first intake valve 04, an exhaust valve 05, a gas chamber end cap 06, an oil chamber housing 07, an oil chamber end cap 08, and an oil chamber piston 09. The gas chamber housing and the gas chamber end cap 06 together form the gas chamber housing 01, wherein the gas chamber housing and the upper end face of the gas chamber piston 02 form a high-pressure gas chamber I, and the gas chamber housing and the lower end face of the gas chamber piston 02 form a low-pressure gas chamber II. The oil chamber housing and the oil chamber end cap 08 together form the oil chamber housing 07, wherein the oil chamber housing and the lower end face of the oil chamber piston 09 form an oil chamber III, and the oil chamber housing and the upper end face of the gas chamber piston 02 form a chamber IV that can be used for vacuuming.

[0053] The double-acting piston assembly includes an oil chamber piston 09, an air chamber piston 02, and a piston rod 03. The oil chamber piston 09 and the oil chamber housing 07, as well as the air chamber piston 02 and the air chamber housing 01, are sealed by a second seal 1A. The piston rod 03 and the oil chamber end cap 08, as well as the piston rod 03 and the air chamber end cap 06, are sealed by a first seal 1B.

[0054] Specifically, the low-pressure air chamber II is also provided with a second suction valve that communicates with the low-pressure air chamber II. The purpose of providing a second suction valve that communicates with the low-pressure air chamber II is to store gas and hydraulic oil at a certain pressure in the high-pressure air chamber, low-pressure air chamber, and oil chamber III respectively before connecting the flow regulator to the diaphragm compressor system.

[0055] Specifically, before the flow regulator is connected to the diaphragm compressor, the height between the top surface of the piston in chamber IV and the oil chamber housing 07 is 1mm to 3mm. During the operation of the flow regulator, in order to rapidly increase the volume of chamber IV and make its internal pressure approximately close to a vacuum, the crankcase and intermediate body of the diaphragm compressor storing hydraulic oil are better evacuated. The dissolved gas in the hydraulic oil is released by vacuum degassing, thereby reducing the gas content of the hydraulic oil in the diaphragm compressor.

[0056] Specifically, the piston rod 03 is provided with scale lines. Based on the known thickness of the gas chamber wall in the flow regulator and the variation of the scale lines on the piston rod 03, the height of chamber IV is limited to 1mm to 3mm.

[0057] Methods for regulating the flow rate of a diaphragm compressor and reducing the air content of the hydraulic oil include the following steps:

[0058] Before the flow regulator is connected to the diaphragm compressor system, it stores gas and hydraulic oil in the high-pressure gas chamber I, low-pressure gas chamber II, and oil chamber III respectively; then it opens the control valve 14 to put the entire system into operation.

[0059] When the diaphragm compressor is in the expansion and intake state, the control unit obtains the flow rate to be regulated based on the flow rate measurement value and the flow rate set value. Then, the control unit processes and analyzes the obtained oil pressure measurement value to obtain the hydraulic oil pressure at the end of the intake of the diaphragm compressor under the working state. The control unit adjusts the intake pressure of the high-pressure air chamber I by adjusting the opening of the electric proportional valve 10, and then adjusts the air pressure of the low-pressure air chamber II at the end of the intake. The piston located in the air chamber housing 01 moves downward under the action of the high-pressure gas in the high-pressure air chamber I, thereby controlling the volume of hydraulic oil in the oil chamber III entering the diaphragm chamber 9 of the diaphragm compressor and increasing the volume of chamber IV, thus reducing the pressure. This achieves the regulation of the flow rate of the diaphragm compressor, while allowing the gas in the crankcase to flow into the chamber IV with a sudden pressure drop through the one-way valve 11, thus evacuating the crankcase.

[0060] When the diaphragm compressor is in the compression and exhaust stage, the hydraulic oil pressure in the diaphragm compressor continuously increases, pushing the piston located in the oil chamber housing 07 to move upward, causing the gas pressure in the high-pressure gas chamber I to continuously rise. When the gas pressure in the high-pressure gas chamber I reaches the exhaust pressure set by the electro-proportional valve 10, it is discharged through the exhaust valve 05. At the same time, the hydraulic oil sent into the oil side diaphragm chamber 9 of the diaphragm compressor in the oil chamber III flows back to the oil chamber III in equal volume, and the volume of the chamber IV becomes smaller, so that the gas pressure in the chamber IV rises to a level greater than atmospheric pressure and is discharged.

[0061] Specifically, the algorithm for precise flow control of the diaphragm compressor in this control unit is as follows:

[0062] The algorithm for precise flow control of the diaphragm compressor in this control unit is as follows:

[0063] To obtain the relationship between the adjustable flow rate of the diaphragm compressor and the volume change of oil chamber III during the working cycle:

[0064] Δq v =Δv oil λ T λ p λ v-e n;

[0065] Where Δv oil λ is the volume of hydraulic oil entering the oil-side diaphragm chamber from oil chamber III at the end of the diaphragm compressor's suction cycle; n is the diaphragm compressor's rotational speed; λ T λ is the temperature coefficient. p λ is the pressure coefficient. v-e Δq is the expansion coefficient of the high-pressure gas inside the clearance volume. v The adjustable flow rate of the diaphragm compressor during the working cycle;

[0066] The relationship between the volume change of oil chamber III and the gas pressure in low-pressure gas chamber II is obtained:

[0067]

[0068] Where v o p1 is the design volume of low-pressure chamber II under the initial state, p0 is the gas pressure in low-pressure chamber II when the diaphragm compressor finishes suction, and m is the process index.

[0069] To obtain the relationship between the gas pressure in the low-pressure chamber II at the end of the suction cycle of the diaphragm compressor, the suction pressure in the high-pressure chamber I, and the hydraulic oil pressure at the end of the suction cycle:

[0070]

[0071] Where p in p is the intake pressure of high-pressure air chamber I. oil S is the pressure of the hydraulic oil in oil chamber III at the end of the intake phase. gas S is the area of ​​the upper surface of the gas chamber piston. oil Let be the area of ​​the lower surface of the piston in the oil chamber, m be the mass of the double-acting piston system, g be the acceleration due to gravity, and p1 be the pressure of the gas in the low-pressure chamber II at the end of the suction cycle of the diaphragm compressor.

[0072] The control unit adjusts the opening of the electro-proportional valve 10 to increase the suction pressure p of the high-pressure air chamber I of the flow regulator. in The value calculated by the control unit is satisfied.

[0073] Specifically, hydraulic oil leakage is not considered in the gas intake and exhaust phases of the diaphragm compressor.

[0074] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A system for regulating the flow rate of a diaphragm compressor and reducing the gas content of hydraulic oil, characterized in that, include: The flow regulator includes a double-acting piston assembly and a gas chamber housing (01) and an oil chamber housing (07) arranged from top to bottom. The double-acting piston assembly has two piston parts, which are respectively disposed in the gas chamber housing (01) and the oil chamber housing (07). This allows the gas chamber housing (01) to be divided into a high-pressure gas chamber I and a low-pressure gas chamber II from top to bottom, while also dividing the oil chamber housing (07) into an oil chamber III and a chamber IV from top to bottom. The high-pressure gas chamber I is provided with a function for regulating... The high-pressure air chamber I has an exhaust valve (05) and a first intake valve (04). Both the exhaust valve (05) and the first intake valve (04) are connected to the air delivery unit through an electric proportional valve (10). The oil chamber III is connected to the oil side diaphragm chamber (9) of the diaphragm compressor through a pipeline. A control valve (14) is provided on the pipeline. The chamber IV is connected to an intake pipe and an exhaust pipe. Both the exhaust pipe and the intake pipe are provided with a one-way valve (11), and the intake pipe is connected to the crankcase of the diaphragm compressor. A flow sensor (12) is used to measure the flow rate of the external exhaust pipe of the diaphragm compressor; The oil pressure sensor (13) is connected to the oil side diaphragm chamber (9) of the diaphragm compressor and is used to monitor the pressure of the oil side diaphragm chamber (9) of the diaphragm compressor under working conditions; The control unit is connected to the flow sensor (12), the oil pressure sensor (13) and two electro-proportional valves (10). The control unit is used to adjust the opening degree of the two electro-proportional valves (10) according to the detection results of the flow sensor (12) and the oil pressure sensor (13).

2. The system for regulating the flow rate of a diaphragm compressor and reducing the gas content of hydraulic oil as described in claim 1, characterized in that, The low-pressure air chamber II is also equipped with a second intake valve that communicates with the low-pressure air chamber II.

3. The system for regulating the flow rate of a diaphragm compressor and reducing the gas content of hydraulic oil as described in claim 1, characterized in that, Before the flow regulator is connected to the diaphragm compressor, the height between the top surface of the piston in chamber IV and the oil chamber housing (07) is 1 mm to 3 mm.

4. The system for regulating the flow rate of a diaphragm compressor and reducing the gas content of hydraulic oil as described in claim 1, characterized in that, The double-acting piston assembly includes a piston rod (03), a piston portion located in the air chamber housing (01) is an air chamber piston (02), and a piston portion located in the oil chamber housing (07) is an oil chamber piston (09). The piston rod (03) passes vertically through the air chamber housing (01) and the oil chamber housing (07) respectively, and is connected to the air chamber piston (02) and the oil chamber piston (09) respectively. The piston rod (03) is sealed to the air chamber housing (01) and the piston rod (03) is sealed to the oil chamber housing (07) by a first sealing element (1B). The oil chamber piston (09) is sealed to the oil chamber housing (07) and the air chamber piston (02) is sealed to the air chamber housing (01) by a second sealing element (1A).

5. The system for regulating the flow rate of a diaphragm compressor and reducing the gas content of hydraulic oil as described in claim 4, characterized in that, The piston rod (03) is provided with scale lines.

6. The method for regulating the flow rate of a diaphragm compressor and reducing the gas content of hydraulic oil as described in claim 1, characterized in that, Includes the following steps: Before connecting the flow regulator to the diaphragm compressor system, gas and hydraulic oil need to be stored in the high-pressure gas chamber I, low-pressure gas chamber II, and oil chamber III of the flow regulator. Then open the control valve (14) to put the entire system into operation; When the diaphragm compressor is in the expansion and intake state, the control unit obtains the flow rate to be regulated according to the flow rate measurement value and the flow rate setting value. Then, the control unit processes and analyzes the obtained oil pressure measurement value to obtain the hydraulic oil pressure at the end of the intake of the diaphragm compressor in the working state. The control unit adjusts the intake pressure of the high pressure chamber I by adjusting the opening of the electric proportional valve (10), and then adjusts the air pressure of the low pressure chamber II at the end of the intake. The piston located in the chamber housing (01) moves downward under the action of the high pressure gas in the high pressure chamber I, thereby controlling the volume of the hydraulic oil in the oil chamber III entering the diaphragm chamber (9) of the diaphragm compressor and increasing the volume of the chamber IV and reducing the pressure, so as to achieve the regulation of the flow rate of the diaphragm compressor and at the same time make the gas in the crankcase flow into the chamber IV with a sudden pressure drop through the one-way valve (11) to evacuate the crankcase. When the diaphragm compressor is in the compression and exhaust stage, the hydraulic oil pressure in the diaphragm compressor continuously increases, pushing the piston located in the oil chamber housing (07) to move upward, causing the gas pressure in the high-pressure gas chamber I to continuously rise. When the gas pressure in the high-pressure gas chamber I reaches the exhaust pressure set by the electric proportional valve (10), it is discharged through the exhaust valve (05). At the same time, the hydraulic oil sent into the oil side diaphragm chamber (9) of the diaphragm compressor by the oil chamber III flows back to the oil chamber III. The volume of the chamber IV becomes smaller, so that the gas pressure in the chamber IV rises to a level greater than atmospheric pressure and is discharged.

7. The method for regulating the flow rate of a diaphragm compressor and reducing the gas content of hydraulic oil as described in claim 6, characterized in that, The algorithm for precise flow control of the diaphragm compressor in this control unit is as follows: To obtain the relationship between the adjustable flow rate of the diaphragm compressor and the volume change of oil chamber III during the working cycle: Δq v =Δv oil l T l p l v-e n; Where Δv oil n is the volume of hydraulic oil entering the oil-side diaphragm chamber from oil chamber III at the end of the diaphragm compressor's suction cycle; n is the rotational speed of the diaphragm compressor. λ T λ is the temperature coefficient. p λ is the pressure coefficient. v-e Δq is the expansion coefficient of the high-pressure gas inside the clearance volume. v The adjustable flow rate of the diaphragm compressor during the working cycle; The relationship between the volume change of oil chamber III and the gas pressure in low-pressure gas chamber II is obtained: Where v o p1 is the design volume of low-pressure chamber II under the initial state, p0 is the gas pressure in low-pressure chamber II when the diaphragm compressor finishes suction, and m is the process index. To obtain the relationship between the gas pressure in the low-pressure chamber II at the end of the suction cycle of the diaphragm compressor, the suction pressure in the high-pressure chamber I, and the hydraulic oil pressure at the end of the suction cycle: Where p in p is the intake pressure of high-pressure air chamber I. oil S is the pressure of the hydraulic oil in oil chamber III at the end of the intake phase. gas S is the area of ​​the upper surface of the gas chamber piston. oil Let be the area of ​​the lower surface of the piston in the oil chamber, m be the mass of the double-acting piston system, g be the acceleration due to gravity, and p1 be the pressure of the gas in the low-pressure chamber II at the end of the suction cycle of the diaphragm compressor.

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