COMPRESSOR ARRANGEMENT FOR COMPRESSING A GAS

Description

[0001] The present invention relates to a compressor arrangement for compressing a gas according to the features of claim 1.

[0002] Compressor systems for compressing a gas, such as hydrogen after electrolysis, are known in the art. Particularly when compressing explosive gas mixtures, there are stringent requirements for explosion protection. To reduce the risk of explosion to the required level, the compressors are generally operated outside of enclosed spaces, allowing any escaping gas to mix directly with the ambient air. To prevent ignition sources, the compressor motors must be encapsulated and often feature thermal winding protection to prevent excessively high temperatures. Such measures are often costly and preclude the use of the compressor system in enclosed spaces.

[0003] Document BE 900218 discloses a compressor for refrigerant which is driven by a liquid.

[0004] Based on the prior art, the object of the present invention is therefore to demonstrate an improved compressor arrangement for compressing a gas, which can be operated in enclosed spaces while complying with explosion protection requirements and can also be manufactured cost-effectively.

[0005] This problem is solved by a compressor arrangement for compressing a gas according to the features of claim 1.

[0006] Advantageous embodiments of the invention are the subject of the dependent claims.

[0007] The compressor arrangement according to the invention for compressing a gas comprises a housing, a hydraulically driven compressor, and a liquid pump. The hydraulically driven compressor and the liquid pump are arranged inside the housing. The housing has a gas inlet and a gas outlet connected to the hydraulically driven compressor. The gas to be compressed is introduced into the hydraulically driven compressor via the gas inlet, compressed therein, and discharged from the housing through the gas outlet for further use or storage.

[0008] The essential feature of the invention is that the housing is at least partially filled with a liquid, so that the hydraulically driven compressor can be driven by a flow of the liquid generated by the liquid pump. The liquid in the housing is drawn in by the liquid pump and then fed into the hydraulically driven compressor at a defined pressure and flow velocity, where the compressor is driven by the flowing liquid. The liquid is then returned to the housing. Thus, a closed circuit is formed.

[0009] The compressor arrangement according to the invention has several advantages. Due to the arrangement of the compressor and the pump within a liquid-filled housing, no additional explosion protection measures are required to meet explosion protection requirements. In particular, the compressor arrangement complies with the ATEX directives of the European Union. The compressor arrangement has a self-contained, modular design. This saves costs and allows the compressor arrangement to be operated in enclosed spaces.

[0010] Furthermore, the hydraulically driven compressor and the liquid pump are cooled by the liquid contained in the housing. This feature also makes the compressor arrangement more cost-effective compared to prior art solutions.

[0011] The compressor arrangement is therefore particularly suitable for decentralized energy supply and home use.

[0012] Preferably, a gas space is formed between the liquid and an upper housing wall. Any gas leaks escaping from the hydraulically driven compressor can be collected in the gas space and discharged as needed.

[0013] The housing preferably features a chimney connection. This is located, in particular, on the upper wall of the housing. Gas contained in the gas chamber can be vented via the chimney connection. Especially when compressing flammable gases, such as hydrogen, leakage gases can be safely and controllably vented from the compressor assembly via the chimney connection. Compared to compressor arrangements known in the prior art, only one connection is required for all relief lines.

[0014] A distance of 1 to 15 cm, and particularly preferably 5 to 10 cm, is preferably formed between the surface of the liquid and the upper housing wall. This has proven advantageous for the previously described functions of the gas space within the scope of the invention.

[0015] In an advantageous embodiment, the housing has an internal volume of 0.05 to 0.5 m³, preferably an internal volume of 0.1 to 0.4 m³, and particularly preferably an internal volume of 0.15 to 0.3 m³. The compact design makes it possible to compress gases, and especially hydrogen, in small quantities. This is advantageous, for example, for the post-compression of small quantities of hydrogen produced by electrolysis.

[0016] Preferably, the compressor assembly or housing can be integrated or arranged in standard 19-inch rack systems. This means the compressor assembly requires little floor space and allows for space-saving integration into existing systems or installations.

[0017] In particular, the liquid pump and the hydraulically driven compressor are completely immersed in the liquid. This ensures that the heat generated during operation of the liquid pump and the hydraulically driven compressor is optimally transferred to the liquid. Furthermore, it guarantees that the liquid pump draws in only the liquid contained within the housing.

[0018] The hydraulically driven compressor is preferably a piston compressor. Piston compressors are simple and robust compressors that require little maintenance and are inexpensive to manufacture.

[0019] The liquid pump is electrically hermetically sealed, preventing the liquid from coming into direct contact with the pump's electronics. A submersible pump is particularly preferred. Submersible pumps are cost-effective, compact, require little maintenance, and are electrically hermetically sealed, especially around their electrical connection. Therefore, submersible pumps are especially well-suited for use in the compressor arrangement described here.

[0020] The liquid pump preferably has an electric drive that can be connected to a standard 230V socket. Therefore, a costly and ATEX-compliant drive is not required.

[0021] The fluid used is primarily water. The water may also contain an additive, such as an antifreeze or rust inhibitor. Water has a high heat capacity and can therefore readily absorb the heat generated by the hydraulically driven compressor and the fluid pump. Furthermore, it is inexpensive, non-flammable, and environmentally friendly. Alternatively, oil can also be used as the fluid.

[0022] The gas to be compressed is preferably hydrogen, the compression of which has become increasingly important in the context of the energy transition.

[0023] A pressure gauge is preferably connected to the gas supply, with which the pre-pressure of the gas to be compressed can be monitored.

[0024] The gas supply can include a shut-off valve, which is preferably located between the pressure gauge and the hydraulically driven compressor. The gas supply can be closed via the shut-off valve if necessary.

[0025] The gas discharge system can also include a pressure gauge and a shut-off valve. The valve is preferably arranged between the pressure gauge and the hydraulically driven compressor.

[0026] In a particularly advantageous embodiment, the gas vent can also include a pressure relief valve. This pressure relief valve can be manually operated and is primarily used for maintenance purposes.

[0027] The liquid pump preferably generates a liquid pressure of 5 to 15 bar, particularly preferably 10 bar. This pressure has proven to be particularly advantageous for driving the hydraulically driven compressor within the scope of the invention.

[0028] Preferably, the liquid pump generates a flow rate of 10 to 30 L / min, particularly 20 L / min. This flow rate has also proven to be optimal in conjunction with the operation of the hydraulically driven compressor.

[0029] The hydraulically driven compressor preferably generates a gas pressure of 250 to 1500 bar, particularly 250 to 350 bar, and most preferably 300 bar. This is a preferred pressure for the further use or storage of the gases, especially hydrogen.

[0030] The hydraulically driven compressor continues to preferably generate a standard volume flow rate of 10 to 40 NL / min.

[0031] The housing can have cooling fins on at least one side. These fins passively cool the fluid inside the housing, preventing the compressor assembly from overheating. Alternatively or additionally, the housing can have an inlet and outlet connected to an additional heat exchanger. This allows the fluid to be fed into the heat exchanger, cooled there, and then returned to the housing.

[0032] The compressor arrangement is explained in more detail below with reference to a purely schematic figure. This serves to facilitate understanding of the invention.

[0033] The Figure 1Figure 1 schematically shows a compressor arrangement 1 for compressing a gas. The compressor arrangement 1 comprises a housing 2, a hydraulically driven compressor 3, and a liquid pump 4. The hydraulically driven compressor 3 and the liquid pump 4 are located inside the housing 2. The housing 2 has a gas inlet 5 and a gas outlet 6 connected to the hydraulically driven compressor 3. The hydraulically driven compressor 3 is supplied with a gas to be compressed, in this example hydrogen, via the gas inlet 5. After the gas has been compressed in the hydraulically driven compressor 3, the compressed gas is discharged from the housing 2 via the gas outlet 6 for further use or storage. The housing 2 has a gas inlet opening 22 and a gas outlet opening 23.The gas inlet 5 and the gas outlet 6 are each shown with dashed lines. The arrows indicate the direction of gas flow.

[0034] According to the invention, the housing 2 is partially filled with a liquid 7. The hydraulically driven compressor 3 can be driven by a flow of the liquid 7 generated by the liquid pump 4. For this purpose, the liquid 7 is drawn directly from the housing 2 by the liquid pump 4 and conveyed to the hydraulically driven compressor 3 via a hydraulic line 8 connecting the liquid pump 4 to the compressor 3. The hydraulically driven compressor 3, which in this embodiment is a piston compressor, is driven by the flowing liquid 7, thus compressing the gas. Subsequently, the liquid 7 is returned to the housing 2. The flow of the liquid 7 is shown in solid lines. The arrows indicate the direction of flow of the liquid 7.

[0035] Compressor assembly 1 meets the requirements of the ATEX directives because there is no separate ignition source. Therefore, no further explosion protection measures are necessary. Furthermore, the arrangement of the liquid pump 4 and the hydraulically driven compressor 3 within the liquid 7 ensures that they are cooled directly by the liquid 7. The temperature of the liquid 7 itself can be controlled by passive cooling with cooling fins arranged on the housing 2 and / or by active cooling using a separate heat exchanger. In the latter case, the housing 2 can have an inlet and outlet opening so that the liquid 7 can be fed to the heat exchanger and then returned to the housing 2. Compared to other solutions known in the prior art, such a cooling system is very cost-effective.

[0036] A gas space 10 is formed between the liquid 7 and an upper housing wall 9 of the housing 2. Any leakage gas escaping from the hydraulically driven compressor 3 can be collected in the gas space 10 and discharged via a chimney connection 11, which is arranged on the upper housing wall 9. Leakage gases generated within the compressor assembly 1 can thus be controlled and discharged at any time.

[0037] A distance A of between 5 and 10 cm is formed between the surface 12 of the liquid 7 and the upper housing wall 9.

[0038] The housing 2 has an internal volume of 0.1 to 0.3 m³. Due to its compact design, the compressor assembly 1 is configured and designed to be installed in a standard 19-inch rack system. The compressor assembly 1 can therefore be integrated into existing systems or installations in a very space-saving manner.

[0039] The liquid pump 4 and the hydraulically driven compressor 3 are completely immersed in the liquid 7. This ensures that the liquid pump 4 can draw in sufficient liquid 7 at all times and that the heat generated by the liquid pump 4 and the hydraulically driven compressor 3 is completely and uniformly dissipated to the liquid 7.

[0040] The liquid pump 4 is a submersible pump. Submersible pumps are cost-effective, small, require little maintenance, and are electrically hermetically sealed. They therefore offer optimal conditions for operation in the compressor arrangement 1 according to the invention.

[0041] The liquid pump 4 has an electric drive which can be connected to a standard 230V socket via a cable 13. The housing 2 has a cable gland 14 through which the cable 13 of the pump 4 can be routed.

[0042] The housing 2 has a drain opening 15 which can be used to drain the liquid 7 contained in the housing.

[0043] A pressure gauge 16 is connected to the gas supply 5, which can be used to check the pre-pressure of the gas to be compressed.

[0044] The gas supply system also includes a shut-off valve 17, which is located between the pressure gauge 16 and the hydraulic compressor 3 at the gas supply 5. The gas supply 5 can be closed via the shut-off valve 17 if necessary.

[0045] The gas discharge 6 also includes a pressure gauge 18 and a shut-off valve 19. The shut-off valve 19 is arranged between the pressure gauge 18 and the hydraulically driven compressor 3.

[0046] The gas outlet 6 also features a pressure relief valve 20. If the gas pressure in the gas outlet 6 is too high, it can be regulated by the pressure relief valve 20. A portion of the gas flow can be diverted from the compressor assembly 1 through a separate housing opening 21. This ensures that the required gas pressure is always present at the gas outlet opening 23 of the gas outlet 6.

[0047] The liquid pump 4 generates a liquid pressure of 10 bar. This has proven to be particularly advantageous for the operation of the hydraulic compressor 3.

[0048] The liquid pump 4 continues to generate a volume flow of 20 L / min, which is also advantageous for the operation of the hydraulic compressor 3.

[0049] The hydraulically driven compressor 3 generates a gas pressure of 300 bar, which is a preferred pressure for further use or storage, especially for hydrogen.

[0050] The hydraulically driven compressor 3 generates a standard volume flow of 10 to 40 NL / min. Reference symbol:

[0051] 1 - Compressor assembly 2 - Housing 3 - Hydraulically driven compressor 4 - Liquid pump 5 - Gas inlet 6 - Gas outlet 7 - Liquid 8 - Hydraulic line 9 - Upper housing wall 10 - Gas chamber 11 - Chimney connection 12 - Surface of 7 13 - Cable 14 - Cable entry 15 - Drain opening 16 - Pressure gauge 17 - Check valve 18 - Check valve 19 - Pressure gauge 20 - Pressure relief valve 21 - Housing opening 22 - Gas inlet opening 23 - Gas outlet opening A - Distance

Claims

1. A compressor assembly (1) for compressing a gas having a housing (2), a hydraulically driven compressor (3) and a liquid pump (4), wherein the hydraulically driven compressor (3) and the liquid pump (4) are arranged inside the housing (2) and the housing (2) has a gas supply (5) connected to the hydraulically driven compressor (3) and a gas discharge (6) connected to the hydraulically driven compressor (3), characterized in that the housing (2) is at least partially filled with a liquid (7) and the hydraulically driven compressor (3) can be driven by means of a flow of the liquid (7) generated by the liquid pump (4).

2. The compressor assembly (1) according to claim 1, characterized in that a gas space (10) is formed between the liquid (7) and an upper housing wall (9).

3. The compressor assembly (1) according to claim 1 or 2, characterized in that the housing (2) has a chimney connection (11), wherein the chimney connection (11) is arranged in particular on the upper housing wall (9).

4. The compressor assembly (1) according to any one of the preceding claims, characterized in that the housing (2) has an internal volume of 0.05 to 0.5 m3, preferably a volume of 0.1 to 0.4 m3 and most preferably of 0.15 to 0.3 m3.

5. The compressor assembly (1) according to any one of the preceding claims, characterized in that the liquid pump (4) and the hydraulically driven compressor (3) are arranged completely within the liquid (7).

6. The compressor assembly (1) according to any one of the preceding claims, characterized in that the hydraulically driven compressor (3) is a piston compressor.

7. The compressor assembly (1) according to any one of the preceding claims, characterized in that the liquid pump (4) is a deep well pump.

8. The compressor assembly (1) according to any one of the preceding claims, characterized in that the liquid (7) is water, wherein the water is in particular mixed with an additive.

9. The compressor assembly (1) according to any one of the preceding claims, characterized in that the gas to be compressed is hydrogen.

10. The compressor assembly (1) according to any one of the preceding claims, characterized in that the liquid pump (4) generates a liquid pressure of 5 to 15 bar, in particular 10 bar.

11. The compressor assembly (1) according to any one of the preceding claims, characterized in that the liquid pump (4) generates a volume flow of 10 to 30 L / min, in particular 20 L / min.

12. The compressor assembly (1) according to any one of the preceding claims, characterized in that the hydraulically driven compressor (3) generates a gas pressure of 250 to 1500 bar, preferably of 250 to 350 bar, most preferably of 300 bar.

13. The compressor assembly (1) according to any one of the preceding claims, characterized in that the hydraulically driven compressor (3) generates a standard volume flow of 10 to 40 NL / min.

14. The compressor assembly (1) according to any one of the preceding claims, characterized in that the compressor assembly (1) is arranged and configured to be installed in a standard 19-inch rack system.