A system for compressing a working fluid and a method thereof

Abstract

Disclosed herein is a system for compressing a working fluid, the system comprising a rotary driver in rotary communication with a shaft of a compressor. The compressor comprises a casing arrangement; and a first compressor section and a second compressor section in the casing arrangement. The first compressor section comprises at least a first compressor impeller mounted on the shaft for rotation therewith and the second compressor section comprises at least a second compressor impeller mounted on the shaft for rotation therewith. At least one of the casing arrangement, the first compressor impeller or the second compressor impeller comprises a metal that is resistant to corrosion by ammonia or hydrogen.

Description

71PRO-511189-WO-2_BHI0597PCTINTEGRAL COMPRESSOR ARRANGEMENT AND METHOD OF MANUFACTURE THEREOFCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of an earlier filing date from ItalianApplication Serial No. 102024000026697 filed November 26, 2024, the entire disclosure of which is incorporated herein by reference.TECHNICAL FIELD

[0002] The present disclosure relates to compressors. Specifically, embodiments disclosed herewith concern integral compressor arrangements and methods of manufacture thereof.BACKGROUND ART

[0003] In several industrial applications a need exists to boost the pressure of a gaseous flow. Dynamic compressors, such as in particular centrifugal compressors, are often used to compress a gaseous flow. The compressor is driven by mechanical power, which is delivered by a driver, such as an electric motor.

[0004] An important aspect in the design of combined compressor configurations includes an efficient energy recovery and optimal operation of the compressor stages. Continuous efforts are made in order to improve efficiency and reliability of operation of these machines.SUMMARY

[0005] In embodiments disclosed herein a compressor is provided, which comprises a casing arrangement and a shaft supported for rotation in the casing arrangement. A first compressor section and a second compressor section are provided in the casing arrangement. The first compressor section comprises a first compressor impeller mounted on the shaft for rotation therewith, and the second compressor section comprises a second compressor impeller mounted on the shaft for rotation therewith.1PRO-511189-WO-2_BHI0597PCT

[0006] Disclosed herein is a system for compressing a working fluid, the system comprising a rotary driver in rotary communication with a shaft of a compressor. The compressor comprises a casing arrangement; and a first compressor section and a second compressor section in the casing arrangement. The first compressor section comprises at least a first compressor impeller mounted on the shaft for rotation therewith and the second compressor section comprises at least a second compressor impeller mounted on the shaft for rotation therewith. At least one of the casing arrangements, the first compressor impeller or the second compressor impeller comprises a material that is resistant to corrosion by ammonia or hydrogen.

[0007] Disclosed herein too is a method of pressurizing a working fluid, the method comprising transporting a working fluid comprising syngas and / or ammonia to a compressor. The compressor comprises a casing arrangement with a first compressor section and a second compressor section in the casing arrangement. The first compressor section comprises at least a first compressor impeller mounted on the shaft for rotation therewith while the second compressor section comprises at least a second compressor impeller mounted on the shaft for rotation therewith. At least one of the casing arrangements, the first compressor impeller or the second compressor impeller comprises a material that is resistant to corrosion by ammonia or hydrogen. The working fluid is pressurized to a first pressure in the first compressor section and then transported at the first pressure to the second compressor section, where it is pressurized to a second pressure. The second pressure is greater than the first pressure.

[0008] A system for compressing a working fluid comprises a rotary driver in rotary communication with a shaft of a compressor; where the compressor comprises a casing arrangement; and a first compressor section in the casing arrangement, the first compressor section comprising at least a first compressor impeller mounted on the shaft for rotation therewith; where at least one of the casing arrangement or the first compressor impeller comprises a material that is resistant to corrosion by ammonia or hydrogen. The system may further comprise one or more additional compressor sections (a second compressor section and / or a third compressor section) arranged within the casing arrangement, where each additional compressor section comprises a separate compressor impeller mounted on the shaft. Each separate compressor impeller is mounted independently on the shaft and comprises a material that is resistant to corrosion by ammonia or hydrogen. The shaft may be mounted on71PRO-511189-WO-2_BHI0597PCT magnetic bearing located in the casing arrangement and is devoid of a lubricant. The casing arrangement is also devoid of a gear box. The compressor may be equipped with active magnetic bearings and driven by a high-speed electric motor equipped with active magnetic bearings, or alternatively, the shaft may be a stacked shaft, and the impeller tip peripheral speeds greater than about 390 m / s to about 600 m / s may be achieved because of the absence of a shrink fit connection. Impeller tip peripheral speeds greater than about 390 m / s are typically considered high-speed for most industrial and commercial applications. Speeds may range from about 390 to about 600 m / s. In another embodiment, the shaft is a stacked shaft, and where impeller tip peripheral speeds are greater than about 390 m / s can be achieved because of the absence of a shrink fit connection.

[0009] In an embodiment, the first compressor section is operative to perform a first stage of compression on the working fluid and where the additional compressor sections (e.g., the second compressor section and / or the third compressor section) are operative to perform a second stage of compression and / or a third stage of compression respectively on the working fluid. Each succeeding stage of compression includes greater pressures than the preceding stage of compression.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A more complete appreciation of the disclosed embodiments of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

[0011] FIG. 1 is a schematic illustration of an exemplary system for compressing syngas and / or ammonia; and

[0012] FIG. 2 depicts an exemplary embodiment of the compressor.DETAILED DESCRIPTION

[0013] Disclosed herein is a system and a method for compressing syngas and / or ammonia using a compressor having multiple stages. In an embodiment, the compressor includes at least two impellers mounted on a single shaft. The rotating components of the compressor sections can be housed in a sealed casing arrangement, with no1PRO-511189-WO-2_BHI0597PCT rotating shaft extending outside the casing, such that seals are not desired, and leakages are avoided. In some embodiments, the shaft is a stacked shaft, such that higher rotational speeds can be achieved due to the absence of the shrink fit connection.

[0014] The compressor according to the present disclosure includes a single shaft, on which several impellers are mounted. The impellers include at least two compressor impellers.

[0015] As defined herein, ammonia synthesis gas, often referred to as syngas, is a mixture of gases that serves as the primary feedstock for the production of ammonia in the Haber-Bosch process. The composition of this gas is carefully controlled to optimize the ammonia synthesis reaction, which combines nitrogen (N2) and hydrogen (H>) to form ammonia (NH3).

[0016] A system for compressing a working fluid comprises a rotary driver in rotary communication with a shaft of a compressor; where the compressor comprises a casing arrangement; and a first compressor section in the casing arrangement, the first compressor section comprising at least a first compressor impeller mounted on the shaft for rotation therewith; where at least one of the casing arrangement or the first compressor impeller comprises a material that is resistant to corrosion by ammonia or hydrogen. The system may further comprise one or more additional compressor sections (a second compressor section and / or a third compressor section) arranged within the casing arrangement, where each additional compressor section comprises a separate compressor impeller mounted on the shaft. Each separate compressor impeller is mounted independently on the shaft and comprises a material that is resistant to corrosion by ammonia or hydrogen. The shaft may be mounted on magnetic bearing located in the casing arrangement and is devoid of a lubricant. The casing arrangement is also devoid of a gear box. In an embodiment, the compressor is equipped with active magnetic bearings and is driven by a high-speed electric motor equipped with active magnetic bearings. In an embodiment t, the shaft is a stacked shaft, where rotary speeds greater than about 390 m / s can be achieved because of the absence of a shrink fit connection.

[0017] In an embodiment, the first compressor section is operative to perform a first stage of compression on the working fluid and where the additional compressor sections (e.g., the second compressor section and / or the third compressor section) are operative to perform a second stage of compression and / or a third stage of compression respectively on1PRO-511189-WO-2_BHI0597PCT the working fluid. Each succeeding stage of compression includes greater pressures than the preceding stage of compression.

[0018] With reference now to FIG. 1, a system 1000 for compressing syngas or ammonia comprises a rotary driver 200 in operative communication with a gear box 300 and a compressor 100. In an embodiment, the rotary driver 200 may be an electric motor, a steam turbine, a gas turbine, a water turbine, a wind turbine, a hydraulic motor, or a combination thereof. Rotary motion from the rotary driver 200 is transmitted to the gear box 300 and the compressor 100 via one or more shafts 400. For example, first shaft 400A transmits rotary motion from the rotary driver 200 to the gear box 300, while second shaft 400B transmits rotary motion from the gear box 300 to the compressor 100.

[0019] The gearbox 300 is optional and is located between an electric motor 200 and the compressor 100 and is operative to modify the speed and torque to meet the operational needs of the compressor 100. The gearbox 300 facilitates an alignment between the motor and compressor shafts and allows for flexibility in layout and design. It ensures that energy from the rotary driver 200 is transmitted efficiently to the compressor 100, minimizing losses. Optimizing speed and torque ensures the compressor 100 operates within its optimal performance range, improving energy efficiency.

[0020] The compressor 100 comprises a single casing that encompasses two or more compressor stages or three or more compressor stages. The multiple stages of a rotary compressor are mounted on the same shaft, the stages work together to progressively compress the working fluid (e.g., syngas and / or ammonia) by increasing its pressure and density at each stage. This arrangement is common in centrifugal, axial, and reciprocating compressors.

[0021] FIG. 2 is a schematic diagram that depicts an exemplary embodiment of the compressor 100 with two compressor sections 114A and 114B, each of which comprises a single stage. With reference now to the FIG. 2, the compressor 100 comprises an integral compressor configuration with a casing arrangement 112. As used herein, the term “casing arrangement” refers to either a single casing that houses a rotating shaft or multiple interconnected compartments (each corresponding to a single compression stage) through which a rotating shaft extends. In an embodiment, the casing arrangement comprises separate casing compartments for each one of the first compressor section 114A and second compressor1PRO-511189-WO-2_BHI0597PCT section 114B, the casing compartments being separated from one another by sealing arrangements along the shaft.

[0022] In the embodiment depicted in FIG. 2, the casing arrangement 112 encloses the compressor sections. These compressor sections include a first compressor section (114A) and a second compressor section (114B). In an exemplary embodiment, both the first and second compressor sections (114A and 114B) may comprise a single stage with a single impeller. Each compressor section may include one or more stages of compression. For example, the first compressor section 114A may perform a first stage of compression on the working fluid, while the second stage of compression may perform a second stage of compression on the same working fluid.

[0023] In another embodiment, each compressor section may perform more than one stage of compression on the working fluid. For example, a first compressor section may perform three sub-stages of compression on a working fluid - a first-first sub-stage, a first-second sub-stage and a first-third sub-stage before transporting the working fluid to a second compressor section, where additional compression stages may occur. Each sub-stage may be performed at a different operating temperature.

[0024] In an embodiment, the first compressor section and the second compressor section are arranged in an in-between bearing configuration (not shown), between the first bearing unit and the second bearing unit. In another embodiment, the first compressor section and the second compressor are arranged in series or alternatively are arranged in parallel. In yet another embodiment, an intercooler is arranged between the first compressor section and the second compressor section.

[0025] Alternative embodiments may include a greater number of sections and / or configurations in which one, some, or all compressor sections feature multiple impellers. In an embodiment, intercoolers may be disposed between successive stages of the compressor.

[0026] Each stage comprises an inlet port and an outlet port. A two-stage compressor therefore contains two inlet ports and two outlet ports for the same working fluid, while a three-stage compressor contains three inlet ports and three outlet ports for the same working fluid. The number of inlet ports or the number of outlet ports is therefore the same as the the number of stages in the compressor. The number of inlet ports is exclusive of ports1PRO-511189-WO-2_BHI0597PCT that are used exclusively for injection of additives. The working fluid discharged from each stage serves as the input for the subsequent stage.

[0027] In an embodiment, each stage of compression is effected by a separate impeller (not shown) contained in a single casing 112. Each stage takes the working fluid output from the previous stage (at higher pressure) and compresses it further. In other words, the second stage lies downstream of the first stage and a third stage lies downstream of the second stage. All stages are mounted on the same shaft, meaning the impellers or pistons are driven by the same power source and rotate or move in synchronization.

[0028] As may be seen in FIG. 2, the compressor 100 comprises at least 3 inlet ports 102, 106 and 108 and at least two outlet ports 104 and 110. First inlet port 102 and first outlet port 104 are the inlets and outlets for the first stage respectively, which receives the initial charge of the working fluid (e.g., syngas and / or ammonia) at a first pressure Pl and compresses it to a second pressure P2 that is greater than Pl. In an embodiment, Pl is at atmospheric pressure. After undergoing compression to pressure P2, the syngas or ammonia leaves the first stage of the compressor at first outlet port 104 and re-enters the compressor at the second inlet port 106, where it is subjected to additional pressurization in a second stage. The syngas or ammonia at pressure P2 is transported to the second inlet port 106 via line 116.

[0029] During the pressurization in the second stage, additives such as, for example, catalysts, corrosion inhibitors, moisture control agents, antifouling agents, lubricants, dehydrating agents, hydrogen sulfide scavengers and the like, may be injected into the second stage via the third inlet port 108. The gases (syngas and / or ammonia) along with additives blended in will then exit the compressor 100 via the second outlet port 110 at a pressure P3 (which is greater than P2).

[0030] The casing arrangement 112, therefore, includes an initial single compressor inlet port 102 (into which the syngas and / or ammonia is introduced at its lowest pressure) and a single final compressor outlet port 110 (from which syngas and / or ammonia is extracted at its highest pressure) with each of the successive stages located therebetween. Each stage is in fluid communication with a preceding stage or with a succeeding stage. The compressor stages 114A and 114B are arranged in series, i.e., in sequence, such that a same gas flow (e.g., syngas and / or ammonia) is processed sequentially in the first stage 114A and in the second stage 114B.71PRO-511189-WO-2_BHI0597PCT

[0031] In centrifugal or axial compressors, an impeller (centrifugal) or rotor blades (axial) accelerate the syngas and / or ammonia, converting rotational energy into kinetic energy. In an embodiment, the syngas and / or ammonia then passes through a diffuser or stator, where the kinetic energy is converted into pressure energy at pressure P2. In reciprocating compressors, the syngas and / or ammonia is drawn into a cylinder, compressed by a piston, and discharged at a pressure P2 that is greater than Pl.

[0032] The output pressure from P2 from the first stage then becomes the input pressure for the second stage. In the second stage, the compression process is repeated, further increasing the pressure to a value of P3 where P3 is greater than P2. In centrifugal compressors, a smaller impeller or specifically designed blade geometry may be used to handle the denser fluid efficiently. In axial compressors, rotor and stator blade angles are adjusted in each stage to account for increasing fluid density. In reciprocating compressors, the fluid enters a smaller cylinder or is compressed by a piston with a shorter stroke to achieve further compression. The last stage delivers the compressed fluid at the desired pressure P3 for the specific application.

[0033] In an embodiment, the initial pressure Pl of the syngas and / or ammonia lies between 0.5 to 5 bar, or 1 to 2 bar, while the final pressure Pn (where n is an integer that represents the nthstage (also referred to herein as the final stage)) is between 100 to 300 bar.

[0034] Set forth below are some embodiments of the foregoing disclosure:

[0035] Embodiment 1: A system for compressing a working fluid, the system including a rotary driver in rotary communication with a shaft of a compressor; where the compressor comprises a casing arrangement, and a first compressor section in the casing arrangement, the first compressor section comprising at least a first compressor impeller mounted on the shaft for rotation therewith; where at least one of the casing arrangement or the first compressor impeller comprises a material that is resistant to corrosion by ammonia or hydrogen, wherein the casing arrangement is devoid of a lubricant.

[0036] Embodiment 2: The system of any prior embodiment , further comprising one or more additional compressor sections arranged within the casing arrangement, where each additional compressor section comprises a separate compressor impeller mounted on the shaft.71PRO-511189-WO-2_BHI0597PCT

[0037] Embodiment 3: The system of any prior embodiment , where the shaft is mounted on magnetic bearings and wherein the system is devoid of a gear box or where the compressor is equipped with active magnetic bearings and is driven by a high-speed motor equipped with active magnetic bearings, or alternatively, where the shaft is a stacked shaft, and where the impeller tip peripheral speeds greater than about 390 m / s to about 600 m / s is achieved because of the absence of a shrink fit connection.

[0038] Embodiment 4: The system as in any prior embodiment, where the rotary driver is at least one of an electric motor, a steam turbine, a gas turbine, a wind turbine, a hydraulic motor, a pneumatic motor, or a combination thereof.

[0039] Embodiment 5 : The system as in any prior embodiment, where each separate compressor impeller is mounted independently on the shaft and comprises a material that is resistant to corrosion by ammonia or hydrogen.

[0040] Embodiment 6: The system as in any prior embodiment, where the first compressor section is operative to perform a first stage of compression on the working fluid and where the additional compressor sections are operative to perform a second stage of compression on the working fluid; where the second stage of compression includes greater pressures than the first stage of compression.

[0041] Embodiment 7: The system as in any prior embodiment, wherein the first compressor section and a second compressor section are arranged in an in-between bearing configuration, between a first bearing unit and a second bearing unit.

[0042] Embodiment 8: The system as in any prior embodiment, wherein the first compressor section and a second compressor are arranged in series.

[0043] Embodiment 9: The system as in any prior embodiment, wherein an intercooler is arranged between the first compressor section and a second compressor section.

[0044] Embodiment 10: The system as in any prior embodiment, wherein the first compressor section and the second compressor section are arranged in parallel.

[0045] Embodiment 11: The system as in any prior embodiment, wherein the shaft is sealingly housed in the casing arrangement.71PRO-511189-WO-2_BHI0597PCT

[0046] Embodiment 12: The system as in any prior embodiment, wherein the casing arrangement comprises separate casing compartments for each one of the first compressor section and a second compressor section, the casing compartments being separated from one another by sealing arrangements along the shaft.

[0047] Embodiment 13: A method of pressurizing a working fluid, the method including transporting a working fluid comprising syngas and / or ammonia to a compressor; where the compressor comprises a casing arrangement, and a first compressor section, the first compressor section comprising at least a first compressor impeller mounted on a shaft for rotation therewith; where at least one of the casing arrangement or the first compressor impeller comprises a material that is resistant of corrosion by ammonia or hydrogen, pressurizing the working fluid to a first pressure in the first compressor section, transporting the working fluid at the first pressure to a second compressor section; and pressurizing the working fluid to a second pressure in the second compressor section; where the second pressure is greater than the first pressure, wherein the casing arrangement is devoid of a lubricant.

[0048] Embodiment 14: The method as in any prior embodiment, where the second pressure is 100 to 300 bar.

[0049] Embodiment 15: The method as in any prior embodiment, where the first pressure is 0.5 to 5 bar.

[0050] Embodiment 16: The method as in any prior embodiment, further comprising the second compressor section and a third compressor section where each of the second compressor section and the third compressor section comprising at least one compressor impeller independently mounted on the shaft for rotation therewith.

[0051] The materials used in the components of the compressor sections such as, for example, impellers, blades, casings, pistons, shafts, and the like, are generally manufactured from materials that are resistant to corrosive action from hydrogen and ammonia.

[0052] Materials used for protection against hydrogen corrosion include austenitic stainless steels (e.g., SS304, SS316, SS321, or a combination thereof, chromium-molybdenum (Cr-Mo) steels (e.g., 214 Cr-lMo, 9Cr-lMo. (or a combination thereof), nickel alloys (e.g., Inconel (nickel-chromium alloy), Monel (nickel-copper alloy), Hastelloy (nickel-molybdenum alloy), low carbon steels, cladded materials (e.g., base materials (e.g., carbon steel) are overlaid71PRO-511189-WO-2_BHI0597PCT with a corrosion-resistant alloy such as stainless steel or Inconel), titanium alloys (grade 2 titanium), ferritic stainless steels (e.g., SS410, SS430, or a combination thereof), special high- strength alloys (Alloy 718 (nickel-chromium-iron- molybdenum), Alloy 625 (nickel- chromium-molybdenum), or a combination thereof.

[0053] The foregoing metals may be coated with chemically resistant polymers, such as, for example, polytetrafluoroethylene, polyolefins, poly siloxanes, or a combination thereof, when used in a compressor.

[0054] The materials used for protection against ammonia attack include carbon steel, stainless steel (e.g., SS304, SS316, and the like), aluminum, nickel and nickel alloys (e.g., Monel (nickel-copper alloy), Inconel (nickel-chromium alloy), or a combination thereof. In an embodiment, these components (used to protect against ammonia degradation) may be coated with chemically resistant polymers, such as, for example, polytetrafluoroethylene, polyolefins, poly siloxanes, or a combination thereof.

[0055] While the invention has been described in terms of various specific embodiments, it will be apparent to those of ordinary skill in the art that many modifications, changes, and omissions are possible without departing from the spirit and scope of the claims. In addition, unless specified otherwise herein, the order or sequence of any process or method stages may be varied or re-sequenced according to alternative embodiments. Specifically, in each of the configurations described above the two compressor sections can be arranged either in series or in parallel, unless differently specified. Also, the two compressors can be alternatively in series or in parallel, unless differently specified.

Claims

71PRO-511189-WO-2_BHI0597PCTCLAIMSWhat is claimed is:

1. A system for compressing a working fluid, the system characterized by: a rotary driver in rotary communication with a shaft of a compressor; where the compressor comprises: a casing arrangement; and a first compressor section in the casing arrangement, the first compressor section comprising at least a first compressor impeller mounted on the shaft for rotation therewith; where at least one of the casing arrangement or the first compressor impeller comprises a material that is resistant to corrosion by ammonia or hydrogen, wherein the casing arrangement is devoid of a lubricant.

2. The system of claim 1, further comprising one or more additional compressor sections arranged within the casing arrangement, where each additional compressor section comprises a separate compressor impeller mounted on the shaft.

3. The system of claim 1, where the shaft is mounted on magnetic bearings and wherein the system is devoid of a gear box or where the compressor is equipped with active magnetic bearings and is driven by a high-speed motor equipped with active magnetic bearings, or alternatively, where the shaft is a stacked shaft, and where the impeller tip peripheral speeds greater than 390 m / s to about 600 m / s is achieved because of the absence of a shrink fit connection.

4. The system of claim 1 , where the rotary driver is at least one of an electric motor, a steam turbine, a gas turbine, a wind turbine, a hydraulic motor, a pneumatic motor, or a combination thereof.

5. The system of claim 2, where each separate compressor impeller is mounted independently on the shaft and comprises a material that is resistant to corrosion by ammonia or hydrogen.71PRO-511189-WO-2_BHI0597PCT6. The system of claim 2, where the first compressor section is operative to perform a first stage of compression on the working fluid and where the additional compressor sections are operative to perform a second stage of compression on the working fluid; where the second stage of compression includes greater pressures than the first stage of compression.

7. The system of claim 1, wherein the first compressor section and a second compressor section are arranged in an in-between bearing configuration, between a first bearing unit and a second bearing unit.

8. The system of claim 1, wherein the first compressor section and a second compressor are arranged in series.

9. The system of claim 1, wherein an intercooler is arranged between the first compressor section and a second compressor section.

10. The system of claim 1, wherein the first compressor section and a second compressor section are arranged in parallel.

11. The system of claim 1, wherein the shaft is sealingly housed in the casing arrangement.

12. The system of claim 1, wherein the casing arrangement comprises separate casing compartments for each one of the first compressor section a second compressor section, the casing compartments being separated from one another by sealing arrangements along the shaft.

13. A method of pressurizing a working fluid, the method characterized by: transporting a working fluid comprising syngas and / or ammonia to a compressor; where the compressor comprises: a casing arrangement; and a first compressor section, the first compressor section comprising at least a first compressor impeller mounted on a shaft for rotation therewith; where at least one of the casing arrangement or the first compressor impeller comprises a material that is resistant of corrosion by ammonia or hydrogen;71PRO-511189-WO-2_BHI0597PCT pressurizing the working fluid to a first pressure in the first compressor section; transporting the working fluid at the first pressure to a second compressor section; and pressurizing the working fluid to a second pressure in the second compressor section; where the second pressure is greater than the first pressure, wherein the casing arrangement is devoid of a lubricant.

14. The method of claim 13, where the second pressure is 100 to 300 bar.

15. The method of claim 13, where the first pressure is 0.5 to 5 bar.

16. The method of claim 13, further comprising the second compressor section and a third compressor section where each of the second compressor section and the third compressor section comprising at least one compressor impeller independently mounted on the shaft for rotation therewith.

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