DK181667B1

DK181667B1 - A diaphragm compressor arrangement and use thereof

Info

Publication number: DK181667B1
Application number: DKPA202270645A
Authority: DK
Inventors: Haastrup Merrild Christian
Original assignee: Cavendish Hydrogen As
Priority date: 2022-12-22
Filing date: 2022-12-22
Publication date: 2024-09-16
Also published as: WO2024132077A1; DK202270645A1

Abstract

Disclosed is a diaphragm compressor arrangement (1) comprising a first diaphragm compressor (2) including a first diaphragm (3) arranged between a first hydraulic fluid chamber (4) and a first gas chamber (5) and it comprises a second diaphragm compressor (6) including a second diaphragm (7) arranged between a second hydraulic fluid chamber (8) and a second gas chamber (9). The diaphragm compressor arrangement (1) further includes a drive arrangement (10) comprising a first cylinder (11) and a second cylinder (12), wherein each of the first and second cylinders (11, 12) comprises a piston (13) and a first piston chamber (14), wherein a piston rod (26) is extending from the piston (13), through the first piston chamber (14), and out through a piston rod hole (15) in an piston rod end (16) of the first piston chamber (14) and wherein each of the first and second cylinders (11, 12) comprises a second piston chamber (17) formed on an opposite side of the piston (13) in relation to the first piston chamber (14). The drive arrangement (10) comprises drive means (18) connected to the piston rod (26) of the first and second cylinders (11, 12), and wherein the drive means (18) are arranged to reciprocate the pistons (13) in the first cylinder (11) and the second cylinder (12) synchronously. Furthermore, the first piston chamber (14) of the first cylinder (11) and the second cylinder (12) is in fluid communication with the first hydraulic fluid chamber (4) and wherein the second piston chamber (17) of the first cylinder (11) and the second cylinder (12) is in fluid communication with the second hydraulic fluid chamber (8).

Description

A DIAPHRAGM COMPRESSOR ARRANGEMENT AND USE THEREOF

Field of the invention

[0001] The invention relates to a diaphragm compressor arrangement comprising a first diaphragm compressor including a first diaphragm arranged between a first

S$ hydraulic fluid chamber and a first gas chamber and a second diaphragm compressor including a second diaphragm arranged between a second hydraulic fluid chamber and a second gas chamber. The invention further relates to use of a diaphragm compressor arrangement.

Background of the invention

[0002] A diaphragm compressor is a variant of the classic reciprocating compressor where the compression of gas occurs by means of a flexible diaphragm (also called a membrane), instead of an intake element. The back and forth moving diaphragm is typically driven by a rod and a crankshaft mechanism so that only the diaphragm and the compressor box come in touch with pumped gas. For this reason this construction is the particularly suited for pumping e.g. explosive gases. However, the traditional diaphragm compressor has some drawbacks in relation to vibrations and difficulties in up-scaling. 10003] Diaphragm compressors are therefore known in many different forms and e.g. from French patent application no. FR925749A it is known to form a double-acting two-stage diaphragm compressor and from Chinese utility model No. CN101408 168 A. it is known to form a double-acting two stage diaphragm compressor with two cylinders each having oil cavities with different size to each drive two diaphragm compressors having different size corresponding to the different oil cavities to create a low-pressure stage and a high pressure stage. However, such a two-stage diaphragm compressor design is complex and space consuming.

[0004] An object of the invention is therefore to provide for an advantageous diaphragm compressor arrangement.

DK 181667 B1 2

Summary of the invention

[0005] The invention relates to a diaphragm compressor arrangement comprising a first diaphragm compressor including a first diaphragm arranged between a first hydraulic fluid chamber and a first gas chamber, and it comprises a second diaphragm compressor including a second diaphragm arranged between a second hydraulic fluid chamber and a second gas chamber. The diaphragm compressor arrangement also includes a drive arrangement comprising a first cylinder and a second cylinder, wherein each of the first and second cylinders comprises a piston and a first piston chamber, wherein a piston rod 1s extending from the piston, through the first piston chamber, and out through a piston rod hole in an piston rod end of the first piston chamber and wherein each of the first and second cylinders comprises a second piston chamber formed on an opposite side of the piston in relation to the first piston chamber. The drive means are connected to the piston rod of the first and second cylinders and the drive means are arranged to reciprocate the pistons in the first cylinder and the second cylinder synchronously. The first piston chamber of the first cylinder and the second cylinder is in fluid communication with the first hydraulic fluid chamber, and the second piston chamber of the first cylinder and the second cylinder is in fluid communication with the second hydraulic fluid chamber,

[0006] Driving the diaphragm compressor arrangement by means of two cylinders connected to the same drive means is advantageous in that the two cylinders enable a more balanced and uniform load on the drive means hereby reducing stress, wear, and vibrations. Furthermore, connecting a first piston chamber of each of the two cylinders to a first diaphragm compressor and connecting the second piston chambers of each of the two cylinders to a second diaphragm compressor ts advantageous in that thereby both the backwards and the forwards motion of the piston in the cylinders can be used for driving a diapbragm compressor while still using only two diaphragm compressors thereby reducing cost, complexity and enabling a more compact design.

[0007] In this context the term “drive means” refers to any kind of drive suited for reciprocating the pistons in two cylinders synchronously. Le. the term includes any

DK 181667 B1 3 kind of motor driven crankshaft, motor driven camshaft and spring arrangement, any kind of rotating disk or arm arrangement or other.

[0008] In an aspect of the invention, the first and second cylinders comprise a guide rod extending from the piston, through the second piston chamber and out through a

S guide rod hole in a guide rod end of the second piston chamber.

[0009] Providing both cylinders with a guide extending from the piston and out of the cylinder in the opposite direction of the piston rod is advantageous in that this provide better and more linear guidance of the piston in the cylinder hereby enabling a better seal between the piston and the cylinder and thereby reducing pressure loss and leakage across the piston. Furthermore, the piston typically comprises sealing means — e.g. in the form of gaskets, O-rings and/or other — and by supporting the piston in both ends of the cylinder the piston is better supported and the life of the seal is thereby prolonged.

[0010] In an aspect of the invention, a piston rod diameter of the piston rod is 1S substantially equal to a guide rod diameter of the guide rod.

[0011] Forming the piston rod with the same diameter as the guide rod throughout the extend of the rods in the cylinders ensures that the cylinder volume hereby is substantially identical on both sides of the piston — i.e. in both stoke directions - and in that the effective piston area hereby is substantially identical on both sides of the piston. This is advantagecus in that both cylinders hereby deliver the same fluid amount at the same pressure no matter the stroke direction and this enables that the diaphragm compressors and any tubing or other between the cylinders and the diaphragm compressor can be formed identical. This is advantageous in that this reduces the number of unique parts thereby reducing assembly cost, handling cost, maintenance cost and it reduces assembly time. Furthermore, the identical cylinder volumes on both sides of the piston ensures a more uniform and balanced operation of the diaphragm compressor arrangement.

In an aspect of the invention, the first piston chamber of the first cylinder and the second cylinder is in fluid communication with the first hydraulic fluid chamber through a first tubing and the second piston chamber of the first cylinder and the second cylinder is in fluid communication with the second hydraulic fluid chamber through a second tubing,

[0012] Enabling fluid communication between the cylinders and the diaphragm compressors through dedicated tubing is advantageous in that this enables simple means for forming the relative complex fluid communication.

[0013] In an aspect of the invention, the first cylinder and the second cylinder are parallel,

[0014] Arranging the first cylinder and the second cylinder to be parallel is advantageous in that this generates a more balanced operation in which the synchronized operation of the pistons in the two cylinders will counteract each other and generate less stress and vibrations.

[0015] In an aspect of the invention, the first cylinder and the second cylinder are arranged on opposite sides of the drive means. 13 0016] Arranging the cylinders on opposite sides of the drive means is advantageous in that the load of the two cylinders hereby will act in opposite directions on the drive means and thereby generate a more balanced load which will prolong the life of the drive means — particularly of any bearings guiding the rotary motion of the drive means. Furthermore a more compact design of the diaphragm compressor arrangement is enabled by arranging the cylinders on opposite sides of the drive means.

[0017] In an aspect of the invention, the diaphragm compressor arrangement is a high-pressure diaphragm compressor arrangement arranged for pressurising a gas in the first gas chamber and the second gas chamber to a pressure between 10 and 300

MPa, preferably between 20 and 200 MPa, and most preferred between 30 and 130

MPa.

[0018] If the pressure is too low the capacity of the diaphragm compressor arrangement 1s too low and if the pressure is too high the risk of leakage or damage increases. Thus, the present pressure ranges present an advantageous relationship between efficiently and function. Furthermore, it should be noted that the present invention is particularly advantageous in relation to high-pressure diaphragm

COMPressor arrangement operating in the present pressure ranges in that one chamber of two cylinders connected to a single diaphragm compressor is particularly suited for 5 generating a high pressure.

[0019] In an aspect of the invention, the drive means are arranged to reciprocate the pistons in the first cylinder and the second cylinder at least 300 times per minute.

[0020] If the drive means are too slow the capacity of the diaphragm compressor arrangement is too low, and it is therefore advantageous that the drive means reciprocate the pistons in the cylinders at least 300 times per minute. [00217 In an aspect of the invention, the first diaphragm compressor is substantially identical to the second diaphragm compressor. [00221 Forming the diaphragm compressors so that they are substantially identical is advantageous in that this reduces the complexity of the diaphragm compressor arrangement, and it reduces the number of unique needed to build and maintain the diaphragm compressor arrangement.

[0023] In an aspect of the invention, the volume of the first hydraulic fluid chamber substantially corresponds to a total cylinder volume of the first piston chambers of the first cylinder and the second cylinder, and the volume of the second hydraulic fluid chamber substantially corresponds to a total cylinder volume of the second piston chambers of the first cylinder and the second cylinder.

[0024] Forming the hydraulic fluid chambers so that their volumes substantially correspond to the volumes of the piston chambers to which they are in fluid communication with is advantageous in that the full capacity of the diaphragm compressors can hereby be utilized even if the volumes of the piston chambers are not the same.

[90025] It should be noted that “substantially correspond” in this embodiment refers to that the total cylinder volume of the piston chambers typically is a few percent larger than the volume of the corresponding hydraulic fluid chamber to compensate for any elastic compression of the hydraulic fluid.

[0026] The invention further relates to use of a diaphragm compressor arrangement according to any of the previously discussed diaphragm compressor arrangements in

S ahydrogen fuelling station. [00271 Using the diaphragm compressor arrangement according to the present invention in a hydrogen fuelling station is particularly advantageous in that in hydrogen fuelling stations compactness 1s important due to the limited space and high efficiency is advantageous in that in that this will speed up the fuelling process.

The drawings

[0028] For a more complete understanding of this disclosure, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts. The figures all illustrate exemplary embodiments of the invention: 13 Figure 1 illustrates a simplified representation of a diaphragm compressor arrangement comprising diaphragm compressors of different size, and

Figure 2 illustrates a simplified representation of a diaphragm compressor arrangement cylinder comprising guide rods.

Detailed description

[0029] Figure 1 illustrates a simplified representation of a diaphragm compressor arrangement comprising diaphragm compressors of different size. [00307 To this embodiment the diaphragm compressor arrangement I comprises a first diaphragm compressor 2 including a first diaphragm 3 arranged between a first hydraulic fluid chamber 4 and a first gas chamber 5, and a second diaphragm compressor 6 including a second diaphragm 7 arranged between a second hydraulic fluid chamber 8 and a second gas chamber 9. Le. in this embodiment the compressors

DK 181667 B1 7 2, 6 are arranged to compress a gas in the gas chambers 5, 9 when the diaphragms 3, 7 are pushed towards the gas chambers 5, 9 by a hydraulic fluid entering and expanding the hydraulic fluid chambers 4, 8. Once the gas in the gas chambers 5, 9 have been compressed it leaves the diaphragm compressors 2, 6 through an exit port 24 and when the hydraulic fluid is sucked out of the hydraulic fluid chambers 4, §, the exit ports 24 closes and gas to be compressed is drawn into the gas chambers 5, 9 through inlet ports 25. To ensure that gas only can travel in the correct direction through the inlet ports 25 and the exit ports 24 the ports 24, 25 are provided with check valves (not shown).

[0031] Inthis embodiment the gas compressed by the diaphragm compressors 2, 6 is hydrogen but in another embodiment the gas could be methane, oxygen or another gås.

[0032] In this embodiment the diaphragm compressor arrangement 1 also comprises a drive arrangement 10 comprising a first cylinder 11 and a second cylinder 12, wherein the first cylinder 11 and the second cylinder 12 in this 18 embodiment are substantially identical. The cylinders 11, 12 are arranged for displacing the hydraulic fluid to and from the hydraulic fluid chambers 4, 8 and thereby drive the compression process in the diaphragm compressors 2, 6. In this embodiment each of the cylinders 11, 12 comprises a piston 13 arranged to travel back and forth in the cylinders 11, 12 to thereby alter the volume of a first piston chamber 14 and a second piston chamber 17 formed on opposite sides of the piston 13 inside the cylinders 11, 12. In this embodiment the travel of the piston 13 is enabled by a piston rod 26 connected to the piston 13 and the piston rod 26 is extending from the piston 13, through the first piston chamber 14, and out through a piston rod hole 15 formed in an piston rod end 16 of the first piston chamber 14. [00331 In this embodiment the piston rods 26 from both cylinders 11, 12 are connected to the same drive means 18 of the drive arrangement 10 by means of connection arms 27. In this embodiment the drive means 18 comprises a crankshaft 28 being rotated by a motor (not shown) — in this case an electrical motor- but in another embodiment the drive means 18 could also or instead comprise other means for generating the reciprocating motion of the pistons 13 in the cylinders 11, 12 —

DK 181667 B1 8 such as a cam or camshaft and spring arrangement or similar known to the skilled person.

[0034] In this embodiment the connection arms 27 are connected to opposite sides of the crankshaft 28 — i.e. 180° displaced — so that when the crankshaft 28 rotates it

S will reciprocate the pistons 13 in the first cylinder 11 and second cylinder 12 synchronously and so that the pistons 13 at all times travel in opposite directions — i.e. either against each other or away from each other — whereby they subject the bearings 29 of the crankshaft 28 to a more balanced and uniform load throughout the full rotation of the crankshaft 28 — e.g. prolonging the life of the bearings 29 — and so — that the motion of the pistons 13 cancels each other out to thereby reduce vibrations generated by the drive arrangement 10.

[9035] In this embodiment the drive arrangement 10 is formed in a drive arrangement housing 30 formed separate from the two diaphragm compressors 2, 6 and in this embodiment the first piston chamber 14 of the first and second cylinders 18 11, 12 are in fluid communication with the first hydraulic fluid chamber 4 through a first tubing 22 and the second piston chamber 17 of the first cylinder 11 and the second cylinder 12 are in fluid communication with the second hydraulic thud chamber 8 through a second tubing 23. In this embodiment the tubing 22, 23 comprises fittings, manifolds, and pipes but in another embodiment the tubing 22, 23 could also or instead comprise valves, filters, pressure gauges and other. [00361 Typically the cylinders 11, 12 and the diaphragm compressors are formed in the same block or housing and the fluid communication between the piston chambers 14, 17 and the hydraulic fluid chambers 4, 8 are established by means of conduits formed internally in the block or housing — e.g, by drilling or casting channels in the — block or housing. However, given the more complex system with merging fluid channels in the present invention it is advantageous to connect the cylinders 11, 12 to the diaphragm compressors 2, 6 through dedicated tubing 22, 23 in this embodiment.

Furthermore, this enables that the diaphragm compressors 2, 6 and the drive arrangement 10 may be manufactured, stored and handled in separate processes thereby reducing cost and increasing flexibility. However, in another embodiment

DK 181667 B1 9 the fluid communication between the piston chambers 14, 17 and the hydraulic fluid chambers 4, 8 would be established by means of conduits formed internally in the block or housing to avoid tubing 22, 23 — e.g., due to problems in forming the tubing 22, 23 leak tight due to the high hydraulic fluid pressure.

S [0037] Inthis embodiment the first cylinder 11 and the second cylinder 12 are arranged to be parallel and coaxial on opposite sides of the drive means 18.

However, in another embodiment the cylinders 11, 12 could be arranged parallel on the same side of the drive means 18 with the centre axis displaced, the cylinders 11, 12 could be arranged parallel with the centre axis displaced on opposite sides of the drive means 18, the cylinders 11, 12 could be arranged slanting on the same side or on opposite sides of the drive means 18 with the centre axis crossed and/or in another embodiment the drive arrangement 10 could comprise more than two cylinders 11, 12 — such as three, four, six or even more.

[0038] In this embodiment the total cylinder volume of the first piston chambers 14 18 of the cylinders 11, 12 is different from the total cylinder volume of the second piston chambers 17 of the cylinders 11, 12 because in this embodiment the piston rod 26 in the first piston chambers 14 reduces the total cylinder volume of the first piston chambers 14 in relation to the total cylinder volume of the second piston chambers 17 and for the same reason the effective surface of the piston 13 is bigger in the second piston chamber 17 than in the first piston chamber 14. For this reason the hydraulic fluid volume delivered to the first hydraulic fluid chamber 4 is smaller than the hydraulic fluid volume delivered to the second hydraulic fluid chamber 8 per full back and forth movement of the pistons 13 and the given the difference in effective surface of the pistons 13 in the two piston chambers 14, 17, the pressure is also — different. Thus, in this embodiment the first diaphragm compressor 2 1s smaller than the second diaphragm compressor 6 in that the volume of the first hydraulic fluid chamber 4 corresponds to the total cylinder volume of both first piston chambers 14 and the volume of the second hydraulic fluid chamber 8 corresponds to the total cylinder volume of both second piston chambers.

DK 181667 B1

[0039] In this embodiment the hydraulic fluid is a liguad in the form of hydraulic oil but in another embodiment the hydraulic fluid could be canola oil, glycol, paraffin oil or another liquid suited for use as a hydraulic fluid in a diaphragm compressor arrangement 1,

S [00401 In this embodiment the diaphragms 3, 7 in the diaphragm compressors 2, 6 are illustrated by a single line. However, in most actual embodiments the diaphragms 3, 7 would be formed by more than one layer such as two, three, four or even more layers.

[0041] Figure 2 illustrates a simplified representation of a diaphragm compressor 10 arrangement 1 cylinder comprising guide rods 19.

[0042] Io this embodiment the first and second cylinders 11, 12 comprise a guide rod 19 connected to the piston 13 and extending from the piston 13, through the second piston chamber 17, and out through a guide rod hole 20 in a guide rod end 21 of the second piston chamber 17, wherein the guide rod end 21 is arranged in the opposite end ofthe cylinders 11, 12 in relation to the piston rod end 16. And in this embodiment the piston rod diameter PD of the piston rod 26 is substantially equal to the guide rod diameter GD of the guide rod 19 throughout the extend of the rods 19, 26 inside the cylinders 11, 12 so that the total cylinder volume of the first piston chambers 14 of the cylinders 11, 12 is substantially identical to the total cylinder volume of the second piston chambers 17 of the cylinders 11, 12. However, in another embodiment the piston rod diameter PD could be different from the guide rod diameter GD — e.g, if different volumes and pressures was desired. The holes 15, 20 in the ends of the cylinders 11, 12 are obviously provided with sealing means (not shown) to ensure that the pressurized hydraulic fluid does not escape the cylinders 11, 12 through the holes 28 15,20.

[0043] Forming the cylinders 11, 12 with a guide rod 19 is advantageous in that the piston 13 hereby is suspended in both ends of the cylinders 11, 13 whereby the piston 13 is less affected by the torque the piston rod 6 18 subject to by the drive means 18 — particularly rotating drive means 18 - and the risk of leakage across the piston 13 from

DK 181667 B1 11 one chamber 14, 17 to the other is reduced. Furthermore, by forming the guide rod 19 effectively identical to the piston rod 6, the total cylinder volume of the first piston chambers 14 are substantially identical to the total cylinder volume of the second piston chambers 17, whereby the first diaphragm compressor 2 can be identical to the second diaphragm compressor 6 - as in this embodiment. This is advantageous in that the tubing 22, 23 hereby also can be formed identical and this mirrored setup means that the diaphragm compressor arrangement 1 can be built by means of fewer unique paris — hereby reducing manufacturing costs — and the diaphragm compressor arrangement I is hereby easier to build, handle, maintain etc. Furthermore this setup also means that the output of the diaphragm compressors 2, 6 is substantially identical in volume and pressure and the output of both diaphragm compressors 2, 6 can hereby be guided to the same compressed gas storage vessel thereby further reducing complexity and cost.

[0044] In this embodiment the diaphragm compressor arrangement 1 is a single stage high-pressure diaphragm compressor arrangement 1 arranged for raising the pressure of the gas in the gas chambers 5, 9 from a pressure around 40 MPa to a pressure around 90 MPa. However, in another embodiment the starting pressure of the gas could be lower — such as 30 MPa, 15 MPa, 5 MPa or even lower — or the starting pressure of the gas could be higher — such as 50 MPa, 60 MPa, 80 MPa or even higher. And/or in another embodiment the pressure could be raised less - such as to 80 MPa, 70 MPa, 50 MPa or even less — or the pressure could be raised more - such as to 100 MPa, 130 MPa, 160 MPa or even more.

[0045] In this embodiment the drive means 18 are arranged to reciprocate the pistons 13 in the first cylinder 11 and the second cylinder 12 at least 300 times per minute to ensure a high capacity of the diaphragm compressor arrangement i. However, in another embodiment ihe drive means 18 could be arranged to reciprocate the pistons less — such as at least 250, 150, 50 times per minute or even less — or the drive means 18 could be arranged to reciprocate the pistons more — such as at least 400, 600, 1,000 times per minute or even more — e.g. depending on the specific capacity of the diaphragm compressor arrangement I, the specific gas or hydraulic fluid, the specific

DK 181667 B1 12 use or other or the drive means 18 could be controlled to reciprocate the pistons 13 in the first cylinder 11 and the second cylinder 12 a variable times per minute e.g. in dependency with a specific desired variable output of the diaphragm compressor arrangement 1, in dependency of one or more operation parameters such as — temperature of hydraulic, fluid, gas or other, time to maintenance, noise level or other.

[0046] In this embodiment the diaphragm compressor arrangement 1 is used for compressing hydrogen in a hydrogen fuelling station (not shown). Le in this embodiment the diaphragm compressor arrangement 1 is used for raising the pressure of hydrogen being delivered to a hydrogen fuelling station before it is stored in a storage vessel (not shown) However, in another embodiment the diaphragm compressor arrangement 1 could be used for raising the pressure of hydrogen during a fuelling process, for maintain the pressure in a storage vessel or in another process in a hydrogen fuelling station. However, in another embodiment the diaphragm compressor arrangement | according to the present invention could is used for 18 compressing another type of gas and/or be used in relation to other processes — such as in a gas manufacturing or storing process, in an industrial facility or other.

[0047] The invention has been exemplified above with reference to specific examples of diaphragm compressor 2, 6, cylinders 11, 12, drive means 18 and other.

However, it should be understood that the invention is not limited to the particular examples described above but may be designed and altered in a multitude of varieties within the scope of the invention as specified in the claims.

List

I. Diaphragm compressor arrangement 2. First diaphragm compressor 3. First diaphragm 4. First hydraulic fluid chamber 5. First gas chamber 6. Second diaphragm compressor 7. Second diaphragm

DK 181667 B1 13 8. Second hydraulic fluid chamber 9. Second gas chamber 10. Drive arrangement 11. First cylinder 12. Second cylinder 13. Piston 14. First piston chamber 15. Piston rod hole 16. Piston rod end 17. Second piston chamber 18. Drive means 19. Guide rod 20. Guide rod hole 21. Guide rod end 22. First tubing 23. Second tubing 24. Exit port 25. Inlet port 26. Piston rod 27. Connection arm 28. Crankshaft 29. Bearing 30. Drive arrangement housing

PD. piston rod diameter

CD. guide rod diameter

Claims

DK 181667 B1 14 PATENT CLAIM

1. Diaphragm compressor arrangement (1) comprising a first diaphragm compressor (2) including a first diaphragm (3) which is placed between a first hydraulic fluid chamber (4) and a first gas chamber (5), a second diaphragm compressor (6), that includes a second membrane (7) which is placed between a second hydraulic fluid chamber (8) and a second gas chamber (9), a drive arrangement (10) comprising a first cylinder (11) and a second cylinder (12), wherein each of the first and second cylinders (11, 12) includes a piston (13) and a first piston chamber (14), with a piston rod (26) extending from the piston (13), through the first piston chamber (14) and out through a piston rod hole (15) in a piston rod end (16) of the first piston chamber (14) and wherein each of the first and second cylinders (11, 12) includes a second piston chamber (17) formed on an opposite side of the piston (13) in relation to the first piston chamber (14), where the drive arrangement (10) comprises drive means (18) connected to the piston rod (26) of the first and second cylinders (11, 12), and where the drive means ( 18) is arranged to move the pistons (13) in the first cylinder (11) and the second cylinder (12) back and forth synchronously, where the first piston chamber (14) of the first cylinder (11) and the second cylinder (12) is in fluid communication with the first hydraulic fluid chamber (4), and where the second piston chamber (17) of the first cylinder (11) and the second cylinder (12) is in fluid communication with the second hydraulic fluid chamber (8), characterized in that the first and second cylinder (11, 12) comprises a guide rod (19) extending from the piston (13), through the second piston chamber (17) and out through a guide rod hole (20) in a guide rod end (21) of the second piston chamber (17) .

2. Diaphragm compressor arrangement (1) according to claim 1, wherein a piston rod diameter (PD) of the piston rod (26) is substantially equal to a guide rod diameter (GD) of the guide rod (19).

DK 181667 B1 15

3. Diaphragm compressor arrangement (1) according to any one of the preceding claims, wherein the first piston chamber (14) of the first cylinder (11) and the second cylinder (12) is in fluid communication with the first hydraulic fluid chamber (4) through a first piping ( 22), and the second piston chamber (17) of the first cylinder (11) and the second cylinder (12) is in fluid communication with the second hydraulic fluid chamber (8) through a second conduit (23).

A diaphragm compressor arrangement (1) according to any one of the preceding claims, wherein the first cylinder (11) and the second cylinder (12) are parallel.

5. Diaphragm compressor arrangement (1) according to any one of the preceding claims, wherein the first cylinder (11) and the second cylinder (12) are arranged on opposite sides of the drive means (18).

6. Diaphragm compressor arrangement (1) according to any one of the preceding claims, wherein the diaphragm compressor arrangement (1) is a high-pressure diaphragm compressor arrangement (1) that is designed to pressurize a gas in the first gas chamber (5) and the second gas chamber (9) to a pressure between 10 and 300 MPa, preferably between 20 and 200 MPa and most preferably between 30 and 130 MPa.

7. Diaphragm compressor arrangement (1) according to any one of the preceding claims, wherein the drive means (18) are arranged to move the pistons (13) back and forth in the first cylinder (11) and the second cylinder (12) at least 300 times per minute.

Diaphragm compressor arrangement (1) according to any one of the preceding claims, wherein the first diaphragm compressor (2) is substantially identical to the second diaphragm compressor (6).

9. Diaphragm compressor arrangement (1) according to any one of the preceding claims, wherein the volume of the first hydraulic fluid chamber (4) essentially corresponds to a combined cylinder volume of the first piston chambers (14) of the first cylinder (11) and the second cylinder (12) ), and where the volume of the second hydraulic fluid chamber (8) essentially corresponds to a combined cylinder volume of the secondary piston chambers (14) of the first cylinder (11) and the second cylinder (12).

10. Use of a diaphragm compressor arrangement (1) according to any one of the preceding claims in a hydrogen filling station.