This International Application claims priority from a Patent Application filed in India having Patent Application No. 201921043132, filed on October 23, 2019, and titled “A CENTRIFUGAL COMPRESSOR ASSEMBLY”.

FIELD OF THE INVENTION

Embodiments of the present disclosure relate to compressor system, and more particularly to, a centrifugal compressor assembly.

BACKGROUND The centrifugal compressors are also termed as radial compressors and are a sub-class of dynamic axial symmetric work-absorbing turbo machinery. The idealized compressive dynamic turbo-machine achieves a pressure rise by adding kinetic energy/velocity to a continuous flow of fluid through the rotor or impeller. This kinetic energy is then converted to an increase in potential energy/static pressure by slowing the flow through a diffuser. The pressure rise in impeller is in most cases almost equal to the rise in the diffuser section.

One of the prior arts discloses a centrifugal compressor diffuser having a mounting surface and plurality of diffuser vanes extending from the mounting surface in an axial direction and forming a pattern around the circumference of the diffuser. The pattern may be determined based upon characteristics of fluid flowing from an impeller across the diffuser and through a scroll of a centrifugal compressor.

Another prior art discloses a diffuser includes a series of vanes configured to enhance diffuser efficiency. The diffusers also include three-dimensional air foil type vanes or two-dimensional cascade-type vanes. The air foil-type vanes provide a greater maximum efficiency. The cascade-type vanes provide enhanced surge flow and choked flow performance.

However, the prior arts have uni-shaped blades that creates lower compression rate. Further the prior art requires high input workload that further reduces the efficiency and also, the prior art fail to implement an integral heat rejection system that results in frequent heating up of the compressor.

Therefore, there is need for a system that can overcome the aforementioned issues. BRIEF DESCRIPTION

In accordance with one embodiment of the disclosure, a centrifugal compressor assembly is provided. The assembly includes a plurality of assemblies, wherein each of the plurality of assemblies includes a first shaft including a first set of rotor blades and a first set of stator blades, wherein the first set of rotor blades imparts energy to a predefined amount of working fluid. Each of the plurality of assemblies includes a second shaft including a second set of rotor blades and a second set of stator blades, wherein each of the first set of stators and the second set of stators include a coolant injection nozzle to supply a predefined amount of coolant, thereby eliminating heat from the predefined amount of working fluid. A plurality of guide fins is placed between consecutive stator blades in the first set of stator blades and the second set of stator blades, respectively, wherein the plurality of guide fins are configured to reduce temperature of the predefined amount of working fluid as a predefined amount of working fluid travels along the plurality of assemblies via the first shaft and the second shaft.

In further embodiment of the present system, the centrifugal compressor assembly includes a plurality of ring headers operatively coupled a plurality of stator blades of each of the plurality of assemblies, wherein the plurality of ring headers is configured to supply a predefined amount of fresh coolant continuously.

In accordance with one embodiment of the disclosure, a method thereof is provided. The method includes receiving, via an inlet, a predefined amount of working fluid by a first set of rotor blades. The method includes receiving, via one or more ring headers, a predefined amount of coolant into the first set of stator blades. The method includes passing predefined amount of received working fluid from the first set of rotor blades to the first set of stator blades, thereby increasing temperature of the predefined amount of received working fluid; and eliminating heat from the predefined amount of received working fluid by the predefined coolant present in the first set of stator blades. To further clarify the advantages and features of the present disclosure, a more particular description of the disclosure will follow by reference to specific embodiments thereof, which are illustrated in the appended figures. It is to be appreciated that these figures depict only typical embodiments of the disclosure and are therefore not to be considered limiting in scope. The disclosure will be described and explained with additional specificity and detail with the appended figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be described and explained with additional specificity and detail with the accompanying figures in which: FIG. 1 illustrates a sectional view of the centrifugal compressor assembly, according to an embodiment of the present invention;

FIG. 2 illustrates an enlarged view of the stator blades of the centrifugal compressor assembly showing cooling mechanism, according to an embodiment of the present invention; FIG. 3 illustrates general view of compressor assembly showing coolant distributor ring headers with coolant feeder tube to stator blade and cut view of internal fins, according to an embodiment of the present invention;

FIG. 4 illustrates view of stator blades through cut view of casing, according to an embodiment of the present invention; FIG. 5 illustrates general comparison of temperature entropy diagram of conventional compressor system and the present disclosure according to an embodiment of the present invention;

FIG. 6 illustrates arrangement and compactness of the centrifugal compressor assembly; and FIG. 7 illustrates a flow chart representing steps involved in a method for FIG. 1 in accordance with an embodiment of the present disclosure.

Further, those skilled in the art will appreciate that elements in the figures are illustrated for simplicity and may not have necessarily been drawn to scale. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the figures by conventional symbols, and the figures may show only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the figures with details that will be readily apparent to those skilled in the art having the benefit of the description herein.

DETAILED DESCRIPTION

For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiment illustrated in the figures and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Such alterations and further modifications in the illustrated system, and such further applications of the principles of the disclosure as would normally occur to those skilled in the art are to be construed as being within the scope of the present disclosure.

The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such a process or method. Similarly, one or more devices or sub-systems or elements or structures or components preceded by "comprises... a" does not, without more constraints, preclude the existence of other devices, sub-systems, elements, structures, components, additional devices, additional sub-systems, additional elements, additional structures or additional components. Appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but not necessarily do, all refer to the same embodiment.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs. The system, methods, and examples provided herein are only illustrative and not intended to be limiting.

In the following specification and the claims, reference will be made to a number of terms, which shall be defined to have the following meanings. The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. FIG. 1 illustrates a pictorial depiction of a centrifugal compressor assembly (100) in accordance with an embodiment of the present disclosure.

The assembly (100) includes a plurality of assemblies, wherein each of the plurality of assemblies includes a first shaft (102) and a second shaft (104). The first shaft (102) includes a first set of rotor blades (102a) and a first set of stator blades (102b). In one embodiment, the first set of rotor blades (102a) are operatively coupled to the first shaft (102) along the length of the first shaft (102). In one embodiment, upon initiation of the centrifugal compressor, the first shaft (102) is configured to rotate at a first predefined speed. In one such embodiment, the first shaft (102) is configured to rotate at a lowest speed. In one embodiment, the first set of stator blades (102b) are placed after the first set of rotor blades (102a).

The second shaft (104) includes a second set of rotor blades (104a) and a second set of stator blades (104b). In one embodiment, the second set of rotor blades (104a) are operatively coupled to the second shaft (104) along the length of the second shaft (104). In one embodiment, the second shaft (104) is configured to rotate at a second predefined speed. In one such embodiment, the second shaft (104) is configured to rotate at a higher speed when compared to the first shaft (102). In one embodiment, the second set of stator blades (104b) are placed after the second set of rotor blades (104a).

In one embodiment, the plurality of assemblies is positioned in a sequence so that a predefined amount of working fluid is gradually passed through the first set of rotor blades (102a), the first set of stator blades (102b), the second set of blades and the second set of stator blades (104b) rotating at gradually increasing speed.

A casing (112) is provided over the first shaft (102) and the second shaft (104), wherein the casing (112) is configured to reduce slip to a substantial extent. In one embodiment, stators are attached to the casing and hence do not rotate.

Each of the plurality of assemblies includes a heat rejection mechanism, wherein the heat rejection mechanism includes a plurality of fins (110) provided on the casing (112) to, wherein the plurality of fins (110) is configured to enhance heat transfer. The plurality of fins (110) is also configured to reduce the temperature of the working fluid as the predefined amount of working fluid travels along the plurality of assemblies. Each stator blades in each of the plurality of assemblies are hollow in nature and each of the stator blades includes a coolant injection nozzle (106). The coolant injection nozzle (106) is configured to ensure continuous supply of a predefined amount of fresh coolant, thereby ensuring continuous removal of heat energy from the predefined amount of working fluid and ensures to cool the predefined amount of working fluid of the centrifugal compressor as it is compressed.

Further, a plurality of guide fins (402, FIG. 4) is placed between two consecutive stator blades in each of the plurality of assemblies. The plurality of guide fins (402) are configured to provide uniform flow distribution to next row of rotor blades and help remove heat energy from the predefined amount of coolant present inside of each of the plurality of stator blades.

The centrifugal compressor assembly (100) also includes one or more ring headers (108) operatively coupled to each row of stator blades in each of the plurality of assemblies, to supply the predefined amount of fresh coolant continuously. Once the heat is reduced from the working fluid, the predefined amount of coolant is discharged through an outlet (604, FIG. 6).

In one embodiment, a plurality of rotors blades and a plurality of stator blades from each of the plurality of assembles rotating at different speeds can be provided from an inlet (602, FIG. 6) to the outlet (604) of the compressor for facilitating the push and pull arrangement for the working fluid.

In one embodiment, the first stage of compression as shown by dotted line (“Fow Speed First Stage Rotor”) and after first stage rotor, a flow straightener may be provided to prepare flow for entry to high speed first stage rotor.

In one embodiment, number of rotor and stator blade rows in each stage of compressor can vary depending on the particular design. Also, number of stages rotating at gradually increasing speed can be optimized based on case to case study. Further, amount of coolant demand for various rows of stators will be different depending on the coolants position in the compressor.

Further, in one embodiment, stators can be provided with internal extended surfaces so as to increase heat transfer area to coolant. FIG. 7 illustrates a flow chart representing steps involved in a method (700) for FIG. 1 in accordance with an embodiment of the present disclosure.

The method (700) includes receiving a predefined amount of working fluid by the first set of rotor blades (102a), wherein the first set of rotor blades (102a) are rotating at a first predefined speed, in step 702.

The method (700) includes supplying a predefined amount of coolant to the first set of stator blades (102b) via the one or more ring headers (108), in step 704.

The method (700) includes passing the predefined amount of received working fluid from the first set of rotor blades (102a) to the first set of stator blades (102b), thereby increasing temperature of the working fluid, in step 706.

The method (700) includes eliminating heat from the predefined amount of received working fluid by the predefined amount of coolant present in the first set of stator blades (102b), in step 708.

This method continues for every row of rotor blades and stator blades throughout the centrifugal compressor assembly.

The present disclosure provides various advantages, including but not limited to, increases the efficiency due to enhanced heat rejection, reduce the workload and achieves high compression rate of the working fluid. The reduction in the workload result in less power consumption. The present disclosure also facilitates zero slip due to special supporting arrangement of stator blades.

The present disclosure’s compression process becomes closer to isothermal process which increases the efficiency. Further, as a result, for every successive row of rotor blades, the predefined amount of working fluid is made available at lower temperature. Hence every successive row of rotor blades receives denser air than that it would have received otherwise. This improves volumetric efficiency of the machine.

Further, a set of rotors present in each of the plurality of assemblies are configured to rotate at a higher speed than the previous consecutive assemblies present in the centrifugal compressor assembly the stage rotor is designed to rotate at higher RPM, thereby allowing the predefined amount of working fluid to be sucked out from the previous assembly more efficiently.

Further, flow of coolant to individual ring header can be optimized by proper sizing of ring header and also by throttling flow to particular ring header, thereby improving cooling of working fluid across the compressor.

Further, the one or more ring headers arrangement is that every stage of compressor receives coolant at same temperature. This helps in maintaining cooling efficiency from inlet to outlet of compressor.

Further, coolant flows over the casing of the compressor before coming out of compressor assembly, thereby creating sound dampening cover for compressor and helps to reduce noise. Further, due to lower average temperature of the mass, thermal stresses in the rotating parts are reduced resulting in increased stability.

While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person skilled in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.

The figures and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, order of processes described herein may be changed and are not limited to the manner described herein. Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts need to be necessarily performed. Also, those acts that are not dependant on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples.