A pressure seal system and method in a positive displacement, central reciprocating machine

Abstract

A pressure-sealing system in a positive displacement, center-reciprocating machine, such as a compressor, having a non-rotatable housing (202; 302) surrounding a pair of first and second rotating parts (208, 217 and 308, 317) movable relative to each other, the first and second rotating parts having coaxial axes of rotation. The housing has an inner circular curved wall (205; 305) and two flat and parallel inner end walls (206, 207; 306, 307). A pair of drive shafts (101; 102) for the rotating component extend in opposite directions. Fluid inlets (231, 232; 331, 332); (229', 230'; 329', 330') and outlets (229, 230; 329, 330); (231', 232'; 331', 332') selectively communicate with an adjustable angular space formed by the relative rotational movement of the rotating component. A pressure seal is formed between the rotating component and the inner wall surface by filling the rotating component with a sealing fluid that contacts at least a portion of the inner wall surface of the housing through an opening on the rotating component.

Description

Background of the Invention This invention relates to a pressure sealing system and method for a positive displacement, center reciprocating machine, as defined in the preamble of the independent claim.

[0002] In current systems and methods for providing pressure seals in positive displacement, center-reciprocating machines, the machine includes: A non-rotatable housing enclosing a pair of movable first and second rotating components having coaxial axes of rotation. The housing has an inner circular curved surface and two flat and parallel inner end walls. A pair of drive shafts for the rotating component, the pair of drive shafts extending in opposite directions; and The fluid inlet and outlet are selectively connected to an adjustable angular space formed by the relative rotational motion of the first and second rotating components within the housing.

[0003] More specifically, in embodiments of a machine using this novel pressure seal, the machine includes: A non-rotatable housing that surrounds a pair of first and second rotating parts that are movable relative to each other, the first and second rotating parts having a coaxial axis of rotation, the housing having an inner circular curved surface and two flat and parallel inner end walls; A pair of drive shafts that coordinate their joint operation and are respectively connected to a rotating component, wherein the drive shaft of the first rotating component extends in a direction opposite to the axis of the drive shaft of the second rotating component; The first rotating component has a hub and at least two radially extending and oppositely oriented wings, the outermost radial ends of the wings having a curved configuration to be controllably movable along the inner circular curved wall of the housing, and the other two opposing parallel wing regions being movable relative to the flat inner end wall of the housing. The second rotating component has a hub and at least two radially extending, oppositely oriented wings. The outermost radial ends of the wings have a curved configuration to allow controllable movement along the inner circular curved wall of the housing. Two other opposing parallel wing regions are movable relative to the flat inner end wall of the housing. Each wing of the second component lies within an adjustable angular space between a pair of wings of the first pair. The axial dimension of the hubs of both the first and second rotating components is half the axial thickness of the wings of both the first and second rotating components. Fluid inlet and outlet are used to selectively communicate with an adjustable angular space generated by the relative rotational motion of the first and second rotating components.

[0004] Existing technology A positive displacement, center reciprocating machine is known, for example, in WO2014 / 112,885. Other related prior art can be found in US2010 / 0,270,752; US2012 / 0,080,006; US3,112,062; US4,169,697; GB2,007,771 and GB2,610,324.

[0005] These machines employ a variety of pressure sealing devices depending on the machine structure, the fluid to be processed, and the practical and technical aspects related to maintenance and repair.

[0006] Pressure seals in positive displacement machines typically employ sliding contact seals made of metal or soft materials, or rely on extremely narrow gaps. These gaps may contain liquid from or injected into the compression chamber, or they may not contain liquid. The aforementioned WO2014 / 112,885 patent uses pressure drop grooves or traps as a method of pressure sealing, while the other documents mentioned disclose the use of conventional pressure sealing methods.

[0007] Purpose of the invention The purpose of this invention is to provide a simpler and more reliable pressure sealing method, particularly for positive displacement machines that require safe and long-term durability, do not require frequent time-related maintenance, or require removal from hard-to-access locations.

[0008] This invention is based on using a bulk sealant as the sealant in a center-reciprocating, positive displacement machine to replace existing pressure seals, thereby forming a pressure seal between the wing sections of a rotating component. The bulk sealant is contained within the respective rotor wing sections, partially through the walls of the moving rotor wing sections and partially through the inner wall of the machine housing. Therefore, by filling the rotating component with sealant and bringing it into contact with at least a portion of the inner wall of the housing through an opening in the rotating component, a pressure seal is formed between the rotating component and the inner wall of the housing.

[0009] In this specification and claims, the term "liquid" refers to a sealing fluid injected into and flowing therefrom into the inner wall of a machine housing of mutually rotating components. Furthermore, the term "fluid" refers to a fluid handled during machining, such as a gas, a gas mixture, a gas-liquid mixture, or a wet gas.

[0010] In the presently preferred embodiments of the invention, the machine is considered to be a compressor, a vacuum pump, an expander, or a hydrodynamic engine.

[0011] In this context, it's understandable that both compressors and vacuum pumps are essentially compressors; they draw in fluid, compress it, and then release it at an outlet pressure higher than the inlet pressure. Both compressors and vacuum pumps must be powered, either by an electric motor or manually. Vacuum pumps are typically optimized for low or very low pressure fluid conditions, while compressors can be used over a wider range of fluid pressures.

[0012] Furthermore, it is understandable that expanders and fluid power engines operate in the opposite manner to compressors. The machine's inlet receives pressurized fluid, which acts on specific surfaces of moving parts within the machine, thereby driving devices such as generators, tools, and propulsion equipment via a main drive shaft. A simple example of an expander is a steam engine, while an example of a fluid power engine could be a drilling rig driven by compressed air. Summary of the Invention

[0013] According to the present invention, a pressure sealing system and a pressure sealing method for a positive displacement, center reciprocating machine are provided, as described in the "Background of the Invention" and the preamble of the appended independent claims.

[0014] The novelty and uniqueness of this pressure sealing system are embodied in its independent claims. More specifically, the novelty of this system lies in: A pressure seal is provided between the rotating component and the inner wall of the housing by means of a rotating component containing a supplied pressurized sealing fluid; the rotating component has openings through which the sealing fluid can contact at least a portion of the surface of the inner wall of the housing; and the gap between the rotating component and the inner wall is filled with the sealing fluid.

[0015] According to a further inventive feature of the pressure sealing system, the system includes: The internal spaces of the hubs and wings of the first and second components are filled with pressure sealing fluid; The adjacent hub surfaces of the first and second components each have a sealing fluid surface supplied from inside the hub, which exists in their common hub clearance; The hub surfaces of the first and second components facing the flat inner end faces of the housing have a sealing fluid surface supplied from inside the hub, so that the sealing fluid exists in the gap between the hub and the flat inner end faces of the housing; and or a) wherein two opposing parallel regions of the wing have a sealing fluid surface provided by an opening leading to the interior of the wing, such that the sealing fluid is present in the gap between adjacent opposing surfaces of the wing and the flat inner end face of the housing, and wherein the curved configuration of the wing is formed by a curved end wall having an axial end configured to allow the sealing fluid to flow out from the interior of the wing and to be present in a defined gap between the curved wall of the wing and the opposing surfaces of the circularly curved inner surface of the housing; or b) wherein the curved configuration of the wing has a sealing fluid surface provided from an opening leading to the interior of the wing to allow the sealing fluid to flow out from the interior of the wing and to exist in a defined gap between adjacent opposing surfaces of the curved end configuration of the wing and the curved inner surface of the housing; and wherein the two opposing parallel regions of the wing have flat walls with radial ends configured to allow the sealing fluid to flow out from the interior of the wing and to exist in a defined gap between adjacent opposing surfaces of the flat inner end face of the wing and the housing.

[0016] The novelty and unique features of this pressure sealing method can be seen from its independent claims. More specifically, a pressure seal between the rotating component and the inner wall of the housing is achieved by filling the rotating component with a sealing fluid, the sealing fluid contacting at least a portion of the surface of the inner wall of the housing through an opening in the rotating component, thereby filling the gap between the rotating component and the inner wall with the sealing fluid, and the sealing fluid being delivered to the rotating component at a pressure higher than that achievable within the adjustable angle space.

[0017] Further embodiments of the systems and methods of the present invention will be apparent from the appended dependent claims and from the detailed description of non-limiting embodiments of the invention taken in conjunction with the accompanying drawings. Brief description of the attached diagram Figure 1 The machine of the present invention and its pressure sealing system, as well as the radially arranged fluid inlet and outlet, are shown.

[0019] Figure 2 It shows Figure 1 An enlarged view of the radially arranged fluid inlet and outlet in the illustrated embodiment.

[0020] Figure 3 It shows Figure 1 An enlarged view of the axially arranged fluid inlet and outlet in the illustrated embodiment.

[0021] Figure 4 Showing Figure 1 and Figure 2 Variations of the illustrated embodiment.

[0022] Figure 5 Showing Figure 2 A partial cross-sectional view, excluding the rotating parts of the machine filled with sealant.

[0023] Figure 6 Showing Figure 3 A partial cross-sectional view, excluding the rotating parts of the machine filled with sealant.

[0024] Figure 7 Showing Figure 2The cross-section of the machine housing containing the rotating parts is shown, and the sealing fluid is indicated.

[0025] Figure 8 Showing Figure 3 The cross-section of the machine housing containing the rotating parts is shown, and the sealing fluid is indicated.

[0026] Figure 9 Showing Figure 7 Enlarged image.

[0027] Figure 10 Showing Figure 8 Enlarged image.

[0028] Figure 11 Showing Figure 5 The middle section shows a view of the rotating parts filled with sealing fluid.

[0029] Figure 12 Showing Figure 11 The image does not include the machine housing; it shows views of rotating parts filled with sealing fluid and shaft seals.

[0030] Figure 13 Showing Figure 6 The image does not include the machine housing and shaft seal, but it shows a view of the rotating parts filled with sealing fluid.

[0031] Figure 14 Showing Figure 5 A local cross-section, and referencing Figure 7 and Figure 9 .

[0032] Figure 15 Showing Figure 6 A local cross-section, and referencing Figure 8 and Figure 10 .

[0033] Figure 16 A pair of first and second rotating components are shown, each having a wing, a hub, and a connected drive shaft, for use in a machine with radial fluid inlets and outlets. The interior of the rotating components is not shown as a sealing fluid.

[0034] Figure 17 yes Figure 16 The interior of the rotating component displays a view of the sealing fluid.

[0035] Figure 18 Showing Figure 16 Rotating components that mesh in a coordinated manner.

[0036] Figure 19 Showing Figure 17 Rotating components that mesh in a coordinated manner.

[0037] Figure 20A pair of first and second rotating components are shown, each having a wing, a hub, and a connected drive shaft, for use in a machine with an axial fluid inlet and outlet. The sealing fluid inside the rotating components is not shown.

[0038] Figure 21 Showing Figure 20 Rotating components that mesh in a coordinated manner.

[0039] Figure 22 Showing Figure 21 View of the rotating component after it has been filled with sealing fluid.

[0040] Figure 23 a-23k illustrates the mutual rotation of two rotating components relative to a radially positioned fluid inlet and outlet on the machine housing.

[0041] Figure 24 a-24k shows Figure 23 A view of a-23k, but involving an axially oriented fluid inlet.

[0042] Figure 25 A simplified schematic diagram illustrates the separation process of the sealing fluid and the processing fluid.

[0043] Detailed description In the description with reference to the accompanying drawings, there are two embodiments relating to the machine inlet and outlet positions, thus implying that the rotating component also has two embodiments. Structural elements of the machine and sealing system in the same position in both embodiments are designated 1xx; structural elements of the machine and sealing elements relating to the radial fluid inlet and outlet are designated 2xx; and structural elements relating to the axial fluid inlet and outlet are designated 3xx, where xx represents consecutive numbers 01, 02, 03, etc.

[0044] This positive displacement, center reciprocating machine is Figure 1 , Figure 2 and Figure 4 Marked as 201, in Figure 3 The machine is marked as 301. It has a non-rotatable housing 202; 302 surrounding a pair of movable rotating parts 208, 217; 308, 317, which have coaxial axes of rotation. The housing has an inner circular curved surface 205; 305 and two flat and parallel inner wall surfaces 206, 207; 306, 307, which serve as the first and second end faces of the housing, respectively.

[0045] A pair of drive shafts 101 and 102 with coordinated joint operation are respectively connected to rotating components 208 and 308; 217 and 317. The drive shaft 101 of the first rotating component 208 and 308 extends in a direction opposite to the axial direction of the drive shaft 102 of the second rotating component 217 and 317. In the currently preferred embodiment of the coordinated joint operation of the pair of drive shafts 101 and 102, a power transmission gear assembly 203 and 204 is provided. Figure 2 ) and 303, 304 ( Figure 3 ), connecting drive shafts 101 and 102 to the common main drive shaft 105. More specifically, in gear assemblies 203 and 204 ( Figure 2 ) and 303, 304 ( Figure 3 At each drive shaft 101, 102, a non-circular gear 103, 104 is connected, wherein the main shaft of the non-circular gear 103 on one shaft 101 forms a first angle (usually 90°, but not necessarily limited to this) with the main shaft of the non-circular gear 104 on the other shaft 102. The non-circular gears 103, 104 are each connected to the main rotating drive shaft 105 through intermediate non-circular gears 106, 106'. The main rotating drive shaft 105 is arranged parallel to the drive shafts 101, 102 of the rotating components 208, 308, 217, 317. The intermediate non-circular gears 106, 106' are driven by circular gears 107, 107', and the circular gears 107' mesh with another circular gear 108, 108' mounted on the main drive shaft 105. If the machine is used as a compressor or vacuum pump, the unit 109 connected to the main drive shaft 105 is an electric motor 109, which provides power to drive the rotating components 208; 308 and 217; 317. If the machine is used as an expander or fluid engine, the unit 109 connected to the main drive shaft 105 is a generator 109, or symbolically, a tool or propulsion device driven by power generated by pressurized fluid acting on the rotating components 208; 308 and 217; 317. It should be understood that the electric motor 109 can be replaced by any other device that provides driving force to the main drive shaft 105.

[0046] The configuration shown combines both non-circular and circular gears, which has the following advantages: the rotational speed (revolutions per minute) can be easily determined by changing the radius of the circular gear; the required distance between the drive shaft of the rotating component and the main drive shaft can be achieved, thereby maintaining a certain distance between the main drive shaft and the machine housing; and the size of the non-circular gear can be reduced to minimize its moment of inertia.

[0047] like Figure 4 As shown, it is conceivable to use only non-circular gears without adding circular gears. The advantage of this approach is that the solution is simpler and the losses caused by gear meshing are less, but the disadvantage is that it may require larger non-circular gears. Figure 1 and Figure 2 Machine 201 in Figure 4Modifications have been made to the coordinated operation of drive shafts 101 and 102. For example... Figure 4 As shown, each drive shaft 101 and 102 is connected to a non-circular gear 103 and 104, and these non-circular gears 103 and 104 on shafts 101 and 102 respectively mesh with corresponding non-circular gears 106'' and 106''' mounted on a rotating main drive shaft 105. This rotating main drive shaft 105 is arranged parallel to the drive shafts 101 and 102 of rotating components 208, 217, 308, 317. As described above, the main drive shaft 105 is driven or is being driven. It should be understood that... Figure 3 Machine 301 in the middle can be modified in a similar way.

[0048] In this context, elliptical or oval-shaped gears are preferred as non-circular gears. Furthermore, non-circular gears may also include gears with other geometries or other operating modes. For example, they may be triangular or square gears, or other polygonal gears. Similarly, eccentric gears are also an option. It is understood that the fluid inlet and outlet and their locations may need to be adjusted according to the selected gear configuration.

[0049] The first rotating component 208; 308 has a hub 209; 309 and at least two radially extending and mutually opposing wings 210, 211; 310, 311, the outermost ends of which have a curved configuration 212; 312 to be controllably movable along the inner curved surface 205; 305 of the housing 202; 302 and maintain a narrow gap with the inner curved surface; and two other opposing parallel wing regions 213, 214 and 215, 216; 313, 314 and 315, 316 are movable relative to the flat inner end faces 206, 207; 306, 307 of the housing 202; 302.

[0050] The second rotating component 217; 317 has a hub 228; 328 and at least two radially extending and mutually opposing wings 219, 220; 319, 320, the outermost radial ends of these wings having a curved configuration 221; 321 to be controllably movable along the inner curved surface 205; 305 of the housing 202; 302 and maintaining a narrow gap with the inner curved surface; and two other opposing parallel wing regions 222, 223 and 224, 225; 322, 323 and 324, 325 are movable relative to the flat inner end faces 206, 207; 306, 307 of the housing 202; 302. Each wing 219, 220, 319, 320 of the second rotating component 217, 317 is located within an adjustable angle space 226, 227, 326, 327 between a pair of wings 210, 211, 310, 311 of the first rotating component 208, 308. The axial dimension of the hubs 209, 309 and 228, 328 of the first and second rotating components 208, 308 and 217, 317 is half the axial thickness t of the wings of the first and second rotating components 208, 308 and 217, 317.

[0051] Fluid inlets 231, 232; 331, 332 and fluid outlets 229, 230; 329, 330 are selectively connected to adjustable angle spaces 226, 227, 326, 327 generated by the relative rotational motion of the first and second rotating components. It should be noted that... Figure 23 and Figure 24 The reference numerals for the fluid inlet and outlet shown in the figures apply to the case where machines 201 and 301 are operating as compressors or vacuum pumps.

[0052] However, if machines 201 and 301 are operated as expanders or hydraulic engines, the fluid inlets are 229' and 230'; 329' and 330', and the fluid outlets are 231' and 232'; 331' and 332', as shown below. Figure 23 and Figure 24 As shown.

[0053] The innovative pressure sealing system described below operates between rotating components 208, 308 and 217, 317 and the inner walls 205, 206, 207, 305, 306, 307 of housing 202; 302.

[0054] As can be seen from the attached figures, the hubs 209, 309, 228, and 328 of the first and second rotating components 208, 308 and 217, 317 are generally hollow structures, and the wings 210, 211; 310, 311 and 219, 220, 319, 320 lack one or two wall surfaces. This is because the internal spaces of the hubs 209, 309, 228, and 328 of the first and second rotating components 208, 308 and 217, 317, and the wings 210, 211, 310, 311 and 219, 220, 319, 320 are filled with a pressure sealing fluid, which is indicated by 233 and 333, respectively. Figure 6 and Figure 7 As shown by the medium-thick shading line, and Figure 8 and Figure 9 As shown by the thin shading.

[0055] The adjacent hub surfaces 234, 235 of the first and second components 208, 308 and 217, 317; 334, 335 each have a liquid surface supplied from inside the hub, existing in their common hub clearance (denoted by reference numerals 236, 336), which in Figure 8 and Figure 9 It is clearly visible in the middle.

[0056] The first and second components 208, 308 and 217, 317 have a liquid surface provided from inside the hubs 209, 309 and 228, 328 on the flat inner wall surfaces 206, 207, 306, 307 facing the housings 202, 302, such that liquid exists in the gap between the hub and the flat inner end face of the housing.

[0057] As described above, if the fluid inlet and outlet are arranged radially on the housing 202 (e.g.) Figure 2 As shown), the two opposing parallel regions 213, 214 and 215, 216 of the wings 211, 210 will form the surface of the sealing fluid 233 flowing into the interior of the wings through the opening 242, thereby providing the sealing fluid 233 to the gap between the wings 210, 211 and the adjacent opposing surfaces of the flat inner wall surfaces 206, 207 of the housing 202. Furthermore, the curved configuration 212 of the wings is formed by curved end walls 239, 240, and the axial end 241 of the wings allows the sealing fluid 233 to flow out from the interior of the wings and exists in the defined gap between the curved walls 239, 240 of the wings and the opposing surfaces of the circularly curved inner wall surface 205 of the housing 202.

[0058] Furthermore, as mentioned above, the fluid inlet and outlet can be arranged axially, such as... Figure 3As shown. In this configuration, the curved configuration 312 of the wing has a liquid surface 333 that flows into the interior of the wing through its opening 339, thereby allowing the sealing fluid 333 to flow out from the interior of the wing and exist in a defined gap between the curved end 312 of the wing and the adjacent opposing surfaces of the circularly curved inner wall surface 305 of the housing 302. The two opposing parallel regions 313, 314 and 315, 316 of the wings 311, 310 have flat walls 353, 354 and 355, 356, the radial ends 340, 341 of which are configured to allow the sealing fluid to flow out from the interior of the wing and exist in a defined gap between the adjacent opposing surfaces of the flat inner wall surfaces 305, 306 of the housing.

[0059] Housings 202 and 302 have multiple sealing fluid inlets 243 and 343, which communicate at their outlets 244 and 344 with dedicated sealing fluid outlet volumes 245 and 345. Each of these volumes is axially constrained by a pair of seals (e.g., sim rings). Volumes 245 and 345 extend circumferentially around the respective shafts 101 and 102, and the sealing fluid therein also acts as a barrier fluid. Each shaft 101 and 102 has sealing fluid inlets 246 and 247, 346 and 347, which communicate with the interior of the wing and the gap 236 and 336 between the hub and the shaft. Therefore, regardless of whether shafts 101 and 102 are rotating or in any rotational position, the sealing fluid 233 and 333 enters the interior of the rotating components through the sealing fluid inlets 243 and 343, outlets 244 and 344, and volumes 245 and 345, and flows into shafts 101 and 102.

[0060] like Figure 6-9 As shown, each hub 209, 228, 309, 328 is provided with a groove 248, 249, 348, 349, and the shaft's sealing fluid inlets 246, 247, 346, 347 lead to this groove for further distribution inside the rotating component.

[0061] To prevent the sealing fluid from leaking into the sleeves 250, 251 and 350, 351 that are integrally formed with the housings 202, 302 (these sleeves surround the drive shafts 101, 102), a sealing device is provided, such as a sim ring 252; 352 or an equivalent sealing device, such as a mechanical seal with a barrier fluid.

[0062] Suitablely, shafts 101, 102 are integrally formed with the first rotating component 208, 308 and the second rotating component 217, 317, at least in the shaft end regions near the hubs 209, 309 and 228, 328 (i.e., the hollow regions 101', 102' on the shaft for receiving and conveying the sealing fluid). The remaining portions of shafts 101, 102 facing their respective free ends (i.e., where the non-circular gears 103, 104 are located) can be integrally formed with or securely connected to said regions 101', 102'.

[0063] In general The LBPS (Liquid Body Pressure Seal) principle described in this invention is applicable to center-reciprocating machines. The rotating blade and its hub are filled with a sealing fluid, which itself provides a pressure seal, rather than using traditional sliding seals, narrow sealing gaps, or pressure drop traps.

[0064] The sealing fluid flows into the wing (as described in conjunction with the accompanying drawings) through a dedicated channel, then flows out of the wing (e.g., through a narrow gap between the wing and the inner wall of the machine housing), and partially mixes with a fluid (e.g., the gas to be compressed) during fluid compression. The mixture of sealing fluid and compressed fluid is then discharged sequentially from the machine outlet at a rate specifically set by the machine. Downstream of the outlet, the sealing fluid separates from the fluid, cools, and is reinjected into the wing, as shown below. Figure 24 As shown, 110 represents the inflow of the fluid to be treated. 111 represents the gas-liquid separator, 112 represents the liquid cooler, 113 represents a check valve or pump, and 114 is the gas outlet of separator 111. The gas-liquid separator 111, connected to the machine outlet, is very useful, especially when the gaseous fluid leaving the machine contains a small amount of sealing fluid. The configuration of the separator, cooler, and pump can be any commercially available model or a custom model, depending on the gas type and the LBPS liquid type.

[0065] As mentioned earlier, if the compression mode is replaced with the expansion mode, the driving fluid can be reused after the sealing fluid (i.e., the sealing fluid component mixed into the driving fluid during equipment operation) is separated from the driving fluid and cooled.

[0066] Understandably, the sealing fluid body 233; 333 is pressurized to a pressure higher than that of the chamber, thereby ensuring that no fluid escapes from the chamber (e.g., Figure 22 253) enters the LBPS liquid.

[0067] The compression pressure range of this machine is suitable to be from 0 to 50 bar (gauge pressure), but is not limited to this range, while the LBPS fluid pressure may appropriately exceed this value by 0.5 to 2.0 bar (gauge pressure). Furthermore, a suitable operating temperature range (non-limiting example) can be selected from -50°C to 250°C. The expansion pressure range may also have a similar numerical range, but it should be understood that for expanders or fluid-driven machinery (e.g., steam engines), the upper limit of the operating temperature may be significantly higher, even exceeding 600°C. However, it should be noted that the actual size of the machine, the materials used, and the appropriately selected sealing fluid will determine the deviation of the actual operating parameters from the above ranges.

[0068] When the invention is applied to a central reciprocating machine (e.g., a compressor or expander), it should be recalled that all rotor blades and their hubs are filled with liquid. The space between the mutually moving rotor blades constitutes a compression chamber or expansion chamber. In a preferred, but non-limiting, embodiment, four such chambers are actually formed. The accompanying drawings show a machine with two rotors, each with two identical blades. Thus, since each blade has two mutually inclined chambers facing the wall, the rotor blades divide the internal compressor or expander capacity into four chambers.

[0069] Using LBPS liquid bodies enables highly efficient fluid pressure sealing between rotor blades, thereby eliminating the friction of traditional sliding seals and improving compressor efficiency.

[0070] The advantage of pressure sealing systems is that there is no mechanical contact between rotor blades, between blade hubs, or between rotor blades and the housing wall. This means that no lubricating oil is needed to lubricate moving parts. Using LBPS fluid other than oil-free fluid, oil-free operation can be achieved without dry-running contact seals. This is advantageous because many compressed fluid applications require the compressed fluid to be free of any oil and impurities generated by dry-running contact sliding seals. Therefore, this also effectively eliminates the problem of wear between contact seals and the housing wall, and significantly extends the required maintenance intervals.

[0071] While oil-free compression or expansion can be achieved using dry-run contact seals, these pressure seals cannot withstand high temperatures. Therefore, this limitation restricts the compression ratio for each compression stage to 3:1 or lower. This invention employs LBPS technology, enabling oil-free compression at higher compression ratios, typically in the range of 3.5:1 to 6:1. Similar considerations apply to expansion operation modes.

[0072] This invention enables properly cooled LBPS liquid to circulate within the hollow rotor blades, thereby cooling the blades in addition to achieving a pressure seal. The outflow of LBPS liquid means that a portion of it enters the chamber, cooling the fluid entering the chamber from the inlet pipe during the fluid intake and compression phases. Due to this cooling characteristic, the density of the inlet fluid increases, further improving compressor efficiency. In fact, the cooling effect of the LBPS liquid on the gas during compression can offset the heating of the fluid during compression due to adiabatic heating, which is often a major cause of compressor inefficiency. Furthermore, since the LBPS liquid mixes with the fluid in the exhaust pipe of the compression chamber, it also cools the fluid after exhaust. This further reduces the fluid's discharge temperature, an advantage that eliminates the need for an aftercooler. However, when the machine is operating as an expander, the cooling effect of the sealing fluid is undesirable, meaning that an uncooled sealing fluid may be more suitable for such machine operation.

[0073] Furthermore, the circulating LBPS fluid can cool compressor components, preventing overheating and reduced strength of machine component materials, thereby improving material utilization and reducing component weight. The reduction in component weight and moment of inertia does indeed improve compressor efficiency. In addition, the cooling effect achieved using LBPS fluid largely avoids dimensional changes in machine materials caused by temperature-induced expansion. This, in turn, results in higher machine precision and smaller sealing gaps, reducing the flow rate of LBPS fluid through these gaps and further improving compressor efficiency. However, if machines 201 and 301 are expanders or hydrodynamic engines, certain trade-offs are necessary, namely, minimizing the cooling effect when the drive fluid mixes with some of the sealing fluid to maintain machine components at a high but controllable and uniform temperature.

[0074] According to the instruction manual and accompanying drawings, this machine mainly operates in two modes: one where the fluid inlet and outlet are arranged radially, and the other where the fluid inlet and outlet are arranged axially. Figure 1 , Figure 2 and Figure 3As shown, aside from the walls facing the compression or expansion chambers, the physical walls on the wing are generally located only at the fluid inlet and outlet to prevent excessive LBPS liquid from entering the compression chamber. Narrow openings are provided laterally along the direction of rotation of the wing on the sides of these defining walls to allow LBPS liquid to drain from the interior of the wing. Therefore, for radial inlet and outlet configurations, the curved ends of the wing have these defining walls, while the two flat sides of the wing facing the flat inner wall of the shell form only "walls" composed of the LBPS liquid body. For axial inlet and outlet configurations, the two flat sides of the wing have these defining walls, while the curved ends of the wing are open, forming only "end walls" composed of the LBPS liquid body. Furthermore, the hub of the wing is also generally open axially to avoid friction between hubs and with machine materials. Therefore, it can be understood that, apart from internal supports for overall structural stability, the number of walls on the wing and its hub is minimal.

[0075] The type of low-flow pretreatment fluid (LBPS) used must be matched to the type of fluid being treated. LBPS liquids can be water, ethylene glycol, or oil-gas condensate, but are not limited to these. The viscosity of the LBPS liquid should be optimized based on gas reflux and viscous friction. However, it is crucial that the type and consistency of the LBPS liquid meet the purity and tolerance requirements of downstream processes for different LBPS liquids. For example, the hydrogen used in fuel cells must not contain any oil, meaning that oil cannot be used as the LBPS liquid during hydrogen compression.

Claims

1. A system for providing a pressure seal in a positive displacement, center-reciprocating machine, the machine comprising: - A non-rotatable housing (202; 302) surrounding a pair of first and second rotating parts (208, 217 and 308, 317) movable relative to each other, the first and second rotating parts having a coaxial axis of rotation, the housing having an inner circular curved surface (205; 305) and two flat and parallel inner end walls (206, 207; 306, 307). - A pair of drive shafts (101; 102) for the rotating components (208, 217 and 308, 317), the pair of drive shafts extending in opposite directions; and - Fluid inlets (231, 232; 331, 332); (229', 230'; 329', 330') and outlets (229, 230; 329, 330); (231', 232'; 331', 332'), wherein the fluid inlets and outlets are selectively connected to an adjustable angular space formed by the rotational movement of the first and second rotating components (208, 217 and 308, 317) relative to each other within the housing. The pressure sealing system is characterized by comprising: - A pressure seal is provided between the rotating component (208; 308 and 217; 317) containing a supplied pressurized sealing fluid (233; 333) and the inner wall (205; 305 and 206, 207; 306, 307) of the housing (202; 302), the rotating component having an opening that allows the sealing fluid to contact at least a portion of the surface of the inner wall (205; 305 and 206, 207; 306, 307) of the housing through the opening and to fill the gap between the rotating component and the inner wall.

2. The pressure sealing system as described in claim 1, in, The pair of drive shafts (101; 102) have coordinated joint operation and are respectively connected to the rotating components (208, 217 and 308, 317), wherein the drive shaft (101) of the first rotating component (208; 308) extends in an axially opposite direction to the drive shaft (102) of the second rotating component (217; 317). The first rotating component (208, 308) has a hub (209; 309) and at least two radially extending and mutually opposing wings (210, 211; 310, 311) from the hub. The outermost radial ends of the wings (210, 211; 310, 311) have a curved configuration (212; 312) to controllably move along the inner circular curved wall (205; 305) of the housing (202; 302). Two other opposing parallel wing regions (213, 214 and 215, 216; 313, 314 and 315, 316) are movable relative to the flat inner end wall (206, 207; 306, 307) of the housing (202; 302). The second rotating component (217; 317) has a hub (228; 328) and at least two radially extending and mutually opposing wings (219, 220; 319, 320) extending from the hub. The outermost radial ends of the wings (210, 211; 310, 311) have a curved configuration (221; 321) to allow controllable movement along the inner circular curved wall (205; 305) of the housing (202; 302). Two additional opposing parallel wing regions (222, 223 and 224, 225; 322, 323 and 324, 325) are parallel to the housing (202; 302). The inner end walls (206, 207; 306, 307) of the tank are movable. Each of the wings (219, 220; 319, 320) of the second rotating component (217; 317) is located within the adjustable angle space (226, 227; 326, 327) of a pair of wings (210, 211; 310, 311) of the first rotating component (208; 209). The axial dimension of the hubs (209; 309 and 228; 328) of the first and second rotating components (208; 308 and 217; 317) is half the axial thickness (t) of the wings of the first and second rotating components. The pressure sealing system further includes: The internal spaces of the hubs (209, 309 and 228, 328) and wings (210, 211, 310, 311 and 219, 220, 319, 320) of the first and second components (208; 308 and 217; 317) are filled with pressure sealing fluid (233, 333). The adjacent hub surfaces (234, 235, 334, 335) of the first and second components (208; 308 and 217; 317) each have a liquid surface provided from inside the hub to exist in their common hub clearance (236; 336). The hub surfaces (237, 238; 337, 338) of the flat inner wall surfaces (206, 207; 306, 307) facing the housing of the first and second components (208; 308 and 217; 317) have a sealing fluid surface supplied from inside the hub, so that fluid exists in the gap between the hub and the flat inner wall surfaces of the housing. or a) Two opposing parallel regions (213, 214 and 215, 216) of the wings (210, 211) have liquid surfaces provided from openings (242) leading to the interior of the wings to provide sealing fluid (233) to the gap between adjacent opposing surfaces of the wings (210, 211) and the flat inner end wall surfaces (206, 207) of the housing, and the curved configuration (212) of the wings (210, 211) is formed by curved end walls (239, 240) having axial ends (241) configured to allow sealing fluid (233) to flow out from the interior of the wings and to exist in the defined gap between the axial ends (241), the circularly curved inner wall surface (205) and the flat inner end wall surfaces (206, 207); or b) The curved configuration (312) of the wing has a sealing fluid surface (333) provided by an opening (339) leading to the interior of the wing to allow the sealing fluid (333) to flow out from the interior of the wing and to be present in a defined gap between adjacent opposing surfaces of the curved end configuration (312) of the wing (311, 310) and the circularly curved inner wall surface (305) of the housing (302), and two opposing parallel regions (313, 314 and 315, 316) of the wing (311, 310) have flat walls (353, 354 and 355, 356) having radial end faces (340, 341) configured to allow the sealing fluid to flow out from the interior of the wing and to be present in a defined gap between adjacent opposing surfaces of the flat inner end wall surface (306, 307) of the housing (302).

3. The system as described in claim 1 or 2, wherein, The housing (202; 302) has multiple sealing fluid inlets (243; 343), and its outlets (244; 344) are connected to a dedicated sealing fluid volume (245; 345). Each shaft (101; 102) has a sealing fluid inlet (246, 247; 346, 347), and the sealing fluid inlets are connected to the interior of the wing and the gap (236; 336) between the hub.

4. The system as described in claim 2 or 3, wherein, Each hub (209, 228; 309, 328) has a recess (248, 249; 348, 349) to which the shaft's sealing fluid inlet (246, 247; 346, 347) leads.

5. The system as described in any one of claims 2-4, wherein, In alternative a), the fluid inlets (231, 232); (229', 230') and outlets (229, 230; 231', 232') are located on the curved wall of the housing (202).

6. The system as described in any one of claims 2-4, wherein, In alternative b), the fluid inlets (331, 332; 329', 330') and outlets (329, 330; 331', 332') are located on the flat end wall of the housing (302).

7. The system as described in any one of claims 2-6, wherein, Coordinated joint operation of the pair of drive shafts (101, 102) is provided by connecting non-circular gears (103, 104) to each drive shaft (101, 102); wherein the non-circular gears (103, 104) of the shafts (101, 102) are each connected to a rotating main drive shaft (105) via intermediate non-circular gears (106, 106'), the rotating main drive shaft being arranged parallel to the drive shafts (101, 102) of the rotating components (208, 217, 308, 317), the intermediate non-circular gears (106, 106') being driven by circular gears (107, 107') meshing with another circular gear (108, 108') mounted on the main drive shaft (105), the main drive shaft (105) being powered by a power unit (109), such as an electric motor or generator, or providing power to the power unit.

8. The system as claimed in any one of claims 2-6, wherein, Coordinated joint operation of the pair of drive shafts (101, 102) is provided by connecting non-circular gears (103, 104) to each drive shaft (101, 102); and wherein the non-circular gears (103, 104) of the shafts (101, 102) mesh with corresponding non-circular gears (106'', 106''') on the main drive shaft (105) of the drive shafts (101, 102) parallel to the rotating components (208, 217; 308, 317), and wherein the main drive shaft (105) is driven by a power unit (109), such as an electric motor or generator, or provides power to the power unit.

9. The system as described in any one of claims 2-8, wherein, The non-circular gears (103; 104; 106; 106'; 106''; 106''') are elliptical or oval in shape.

10. The system as claimed in any one of claims 1-9, wherein, The machine (201; 301) has a compressor or vacuum pump operating mode, and wherein the fluid outlet (231, 232; 331, 332) is connected to a gas / sealing fluid separator (111) configured to separate the sealing fluid (233; 333) from the compressed gas phase fluid and deliver the gas phase fluid to the first separator output (114), and wherein the separated sealing fluid is cooled in a cooler (112) and delivered back to the first and second rotating components of the machine (202; 302) by a pump (113).

11. The system of claim 10, wherein, The sealing fluid pressure is within the range of 0.5 to 2.0 bar (gauge pressure) above the compression pressure value.

12. A method for providing a pressure seal in a positive displacement, center-reciprocating machine, the machine comprising: - A non-rotatable housing (202; 302) surrounding a pair of first and second rotating parts (208, 217; 308, 317) movable relative to each other, the first and second rotating parts having a coaxial axis of rotation, the housing having an inner circular curved surface (205; 305) and two flat and parallel inner end walls (206, 207; 306, 307). - A pair of drive shafts (101; 102) for the rotating components (208, 217; 308, 317), the pair of drive shafts extending in opposite directions; and - Fluid inlets (231, 232; 331, 332); (229', 230'; 329', 330') and outlets (229, 230; 329, 330); (231', 232'; 331', 332'), wherein the fluid inlets and outlets are selectively connected to an adjustable angular space formed by the relative rotational motion of the first and second rotating components (208; 308 and 217; 317) within the housing. The pressure seal between the rotating components (208, 217; 308, 317) and the inner walls (205; 305 and 206, 207; 306, 307) of the housing (202; 302) is provided by filling the rotating components (208; 308 and 217; 317) with a sealing fluid (233; 333), which contacts at least a portion of the surface of the inner walls (205; 305 and 206, 207; 306, 307) of the housing through an opening in the rotating components, thereby filling the gap between the rotating components and the inner walls. The sealing fluid (233; 333) is delivered to the rotating component (208, 217; 308, 317) at a pressure higher than that achievable within the adjustable angle space.

13. The method of claim 12, wherein, The sealing fluid pressure is in the range of 0.5 to 2.0 bar (gauge pressure) higher than the pressure value within the adjustable angle space.

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