Abstract:
According to an aspect of an exemplary embodiment, there is provided a compressing system including: a casing including an inlet and an outlet; a first compression unit configured to receive an inlet fluid from the inlet and compressing the inlet fluid into a first pressure fluid; a first pressure chamber configured to receive the first pressure fluid; at least one first intercooler unit configured to cool the first pressure fluid; a second compression unit configured to compress the first pressure fluid into a second pressure fluid; a second pressure chamber configured to receive the second pressure fluid; at least one second intercooler unit configured to cool the second pressure fluid; and a third compression unit configured to compress the second pressure fluid.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
       [0001]    This application claims priority from Korean Patent Application No. 10-2012-00105937, filed on Sep. 24, 2012 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    Apparatuses consistent with exemplary embodiments relate to a compressing system. 
         [0004]    2. Description of the Related Art 
         [0005]    Compressors for compressing fluids, such as the air, gases, and steam, are used in various fields and various types of compressors are available. 
         [0006]    In the related art, compressors may be categorized into displacement type compressors and turbo type compressors. In more detail, compressors may be categorized into reciprocating compressors, rotary screw compressors, turbo compressors, diaphragm compressors, and rotary sliding vane compressors. 
         [0007]    Such a compressor may be used alone. However, if necessary, a multi-stage system may be configured by arranging a plurality of compressors, where the multi-stage system may feature greater compression ratio. 
         [0008]    When employing the plurality of compressors, a cooler may be disposed between the compressors for improving system efficiency. For example, Korean Patent Publication No. 2010-0107875 discloses a multi-stage compressive system which requires no separate cooling system due to having coolers disposed between compressors and a coolant circulating structure. 
       SUMMARY 
       [0009]    One or more exemplary embodiments provide a highly efficient compressing system for compressing a large amount of a fluid. 
         [0010]    According to an aspect of an exemplary embodiment, there is provided a compressing system including: a casing, which includes an inlet and an outlet; a first compression unit disposed inside the casing and configured to receive an inlet fluid from the inlet and compress the inlet fluid into a first pressure fluid; a first pressure chamber disposed inside the casing and configured to communicate with an outlet of the first compression unit to receive the first pressure fluid; at least one first intercooler unit disposed in the first pressure chamber and configured to cool the first pressure fluid; a second compression unit disposed inside the casing, configured to communicate with an outlet of the first pressure chamber to receive the first pressure fluid from the first pressure chamber, and compress the first pressure fluid into a second pressure fluid; a second pressure chamber disposed inside the casing and configured to communicate with an outlet of the second compression unit to receive the second pressure fluid; at least one second intercooler unit disposed in the second pressure chamber and configured to cool the second pressure fluid; and a third compression unit disposed inside the casing and configured to communicate with an outlet of the second pressure chamber to receive the second pressure fluid from the second pressure chamber, and compress the second pressure fluid. 
         [0011]    The casing may further include an upper casing and a lower casing coupled to the bottom of the upper casing. 
         [0012]    The first compression unit may include at least one of an axial compressor and a mixed-flow compressor. 
         [0013]    The second compression unit may comprise at least one of a mixed-flow compressor and a centrifugal compressor. 
         [0014]    The third compression unit may comprise at least one centrifugal compressor. 
         [0015]    The compressing system may further include a single rotation shaft configured to drive the first compression unit, the second compression unit, and the third compression unit. 
         [0016]    At least one additional intercooler unit may be provided outside the casing. 
         [0017]    The first compression unit may include a movable vane configured to control a change of an amount of the inlet fluid. 
         [0018]    According to an aspect of an exemplary embodiment, there is provided a compressing system including: at least three compression units configured to compress a fluid; at least two compression chambers disposed between the at least three compression units, each of the at least two compression chambers configured to communicate with two of the at least three compression units; and at least two intercooler units disposed in the at least two compression chambers and configured to cool the fluid, wherein the at least three compression units, the at least two compression chambers and the at least two intercooler units are disposed inside a casing, and wherein each of a number of the at least two compression chambers and a number of the at least two intercooler units is less than a number of the at least three compression units by one. 
         [0019]    The casing may include an inlet configured to provide the fluid to the at least three compression units; and an outlet configured to eject the compressed fluid. 
         [0020]    A compression unit of the at least three compression units disposed closest to the inlet of the casing may include at least one of an axial compressor and a mixed-flow compressor. 
         [0021]    A compression unit of the at least three compression units disposed closest to the outlet of the casing may include at least one centrifugal compressor. 
         [0022]    The compression unit of the at least three compression units disposed closest to the inlet of the casing may include a movable vane configured to control a change of an amount of the fluid. 
         [0023]    The compressing system may further include a shaft configured to drive each of the at least three compression units. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    The above and/or other aspects will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: 
           [0025]      FIG. 1  is a schematic perspective view of a compressing system according to an exemplary embodiment; 
           [0026]      FIG. 2  is a schematic perspective view of the compressing system according to an exemplary embodiment not including an upper casing and front intercooler units to illustrate the internal structure of the compressing system; 
           [0027]      FIG. 3  is a schematic sectional view of the compressing system of  FIG. 1  along a line III-III of  FIG. 1  according to an exemplary embodiment; 
           [0028]      FIG. 4  a schematic sectional view of the compressing system of  FIG. 1 , obtained along a line IV-IV of  FIG. 1  according to an exemplary embodiment; and 
           [0029]      FIG. 5  is a schematic diagram showing a configuration of the compressing system according to an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    The exemplary embodiments will be described more fully with reference to the accompanying drawings. In the drawings and specification, like reference numerals are used to elements having substantially like configurations. 
         [0031]      FIG. 1  is a schematic perspective view of a compressing system according to an exemplary embodiment and  FIG. 2  is a schematic perspective view of the compressing system according to an exemplary embodiment not including an upper casing and front intercooler units to illustrate an internal structure of the compressing system.  FIG. 3  is a schematic sectional view of the compressing system of  FIG. 1  obtained along a line III-III of  FIG. 1  according to an exemplary embodiment, and  FIG. 4  a schematic sectional view of the compressing system of  FIG. 1  along a line IV-IV of  FIG. 1  according to an exemplary embodiment. Furthermore,  FIG. 5  is a schematic diagram showing configuration of the compressing system according to an exemplary embodiment. 
         [0032]    As shown in  FIGS. 1 through 5 , a compressing system  100  includes a casing  110 , a first compression unit  120 , a first pressure chamber  130 , first intercooler units  140 , a second compression unit  150 , a second pressure chamber  160 , second intercooler units  170 , a third compression unit  180 , a rotation shaft  190 , a driving motor  195 , and a control device  197 . 
         [0033]    The casing  110  includes an upper casing  111  and a lower casing  112 , and the casing  110  is assembled by coupling the upper casing  111  and the lower casing  112  together. 
         [0034]    The casing  110  has an overall hexahedral shape, however, the exemplary embodiment is not limited thereto. The first compression unit  120 , the first pressure chamber  130 , the first intercooler units  140 , the second compression unit  150 , the second pressure chamber  160 , the second intercooler units  170 , and the third compression unit  180  are disposed inside the casing  110 . 
         [0035]    An inlet  113  via which a fluid flows in is formed at a first side of the casing  110 , whereas an outlet  114  via which a fluid flows out is formed at a second side of the casing  110 . 
         [0036]    As shown in  FIG. 4 , oil is provided in the lower casing  112  to improve lubrication during operation of the compressing system  100 . 
         [0037]    The first compression unit  120  receives a fluid from the inlet  113  and compresses the fluid. To this end, the first compression unit  120  includes a two-stage axial compressor  121 . 
         [0038]    The axial compressor  121  includes a first rotation body  121   a , a second rotation body  121   b , and a stator  121   c.    
         [0039]    The first rotation body  121   a  includes a first hub  121   a _ 1  and a first blade  121   a _ 2  installed to the first hub  121   a _ 1 , whereas the second rotation body  121   b  includes a second hub  121   b _ 1  and a second blade  121   b _ 2  installed to the second hub  121   b _ 1 . 
         [0040]    The first hub  121   a _ 1  and the second hub  121   b _ 1  are fixed to the rotation shaft  190 , and when the rotation shaft  190  rotates, the first rotation body  121   a  and the second rotation body  121   b  also rotate. 
         [0041]    The stator  121   c  has a cylindrical tubular shape, and a movable vane  121   c _ 1  and a fixed vane  121   c _ 2  are installed on the inner surface of the stator  121   c  to guide a fluid. Particularly, a movement of the movable vane  121   c _ 1  is controlled by the control device  197  to control an amount of fluid. 
         [0042]    An inlet  120   a  of the first compression unit  120  is formed to communicate with the inlet  113  to receive a fluid from the inlet  113 . On the other hand, an outlet  120   b  of the first compression unit  120  is formed to communicate with the first pressure chamber  130 . 
         [0043]    According to the exemplary embodiment, the first compression unit  120  includes the two-stage axial compressor  121 . However, the exemplary embodiment is not limited thereto. In other words, the first compression unit  120  may include a single-stage axial compressor, a three or more-stage axial compressor, or a mixed-flow compressor. 
         [0044]    Furthermore, according to the exemplary embodiment, the first compression unit  120  includes the single axial compressor  121 . However, the exemplary embodiment is not limited thereto. In other words, the first compression unit  120  according to the exemplary embodiment may include a plurality of compressors. 
         [0045]    Meanwhile, according to the exemplary embodiment, the first compression unit  120  is an axial compressor or a mixed-flow compressor, because an axial compressor or a mixed-flow compressor is capable of easily compressing a large amount of a fluid with a large specific volume and is also capable of compressing a large amount of a fluid more efficiently than a centrifugal compressor. 
         [0046]    Meanwhile, the first pressure chamber  130  communicating with the outlet  120   b  of the first compression unit  120  is disposed inside the casing  110 . 
         [0047]    The first pressure chamber  130  is a hollow hexahedral structure via which a fluid of a first pressure flows. The first pressure refers to pressure of a fluid compressed by the first compression unit  120  and is determined based on the efficiency of the first compression unit  120 . 
         [0048]    The first pressure chamber  130  includes an inlet  130   a  and an outlet  130   b.    
         [0049]    The inlet  130   a  of the first pressure chamber  130  is formed to communicate with the outlet  120   b  of the first compression unit  120  to receive the fluid of the first pressure, whereas the outlet  130   b  of the first pressure chamber  130  is formed to communicate with an inlet  150   a  of the second compression unit  150  to transfer the fluid of the first pressure to the second compression unit  150 . 
         [0050]    Meanwhile, a pair of the first intercooler units  140  is disposed in the first pressure chamber  130  to face each other and cool a fluid in the first pressure chamber  130 . 
         [0051]    Although a pair of the first intercooler units  140  is used in the exemplary embodiment, the exemplary embodiment is not limited thereto. In other words, one, three, or more first intercooler units  140  may be used. 
         [0052]    The first intercooler units  140  may have a hexahedral shape, and the internal structure of the first intercooler units  140  may be an intercooler structure known in the art. In other words, the first intercooler units  140  have heat exchange units to lower temperature of a fluid. 
         [0053]    Meanwhile, the second compression unit  150  receives a fluid from the first pressure chamber  130  and compresses the fluid. To this end, the second compression unit  150  includes a mixed-flow compressor  151 . In other words, the inlet  150   a  of the second compression unit  150  is formed to communicate with the outlet  130   b  of the first pressure chamber  130  for receiving a fluid from the outlet  130   b  of the first pressure chamber  130 . On the other hand, an outlet  150   b  of the second compression unit  150  is formed to communicate with the second pressure chamber  160 . 
         [0054]    Meanwhile, the mixed-flow compressor  151  includes an impeller  151   a  and a case  151   b , and has the general configuration of a mixed-flow compressor known in the art. 
         [0055]    The impeller  151   a  includes a hub  151   a _ 1  and a blade  151   a _ 2  disposed at the hub  151   a _ 1 . The hub  151   a _ 1  is fixed to the rotation shaft  190 , and when the rotation shaft  190  rotates, the impeller  151   a  rotates too. 
         [0056]    According to the exemplary embodiment, the second compression unit  150  includes the mixed-flow compressor  151 . However, the exemplary embodiment is not limited thereto. In other words, the second compression unit  150  according to the exemplary embodiment may be a centrifugal compressor. 
         [0057]    Furthermore, according to the exemplary embodiment, the second compression unit  150  includes the single mixed-flow compressor  151 . However, the exemplary embodiment is not limited thereto. In other words, the second compression unit  150  according to the exemplary embodiment may include a plurality of compressors  151 . 
         [0058]    Meanwhile, the second pressure chamber  160  communicating with the outlet  150   b  of the second compression unit  150  is disposed inside the casing  110 . 
         [0059]    The second pressure chamber  160  is a hollow hexahedral structure via which a fluid of a second pressure flows. The second pressure refers to pressure of a fluid compressed by the second compression unit  150  and is determined based on the first pressure described above and the performance of the second compression unit  150 . 
         [0060]    The second pressure chamber  160  includes an inlet  160   a  and an outlet  160   b.    
         [0061]    The inlet  160   a  of the second pressure chamber  160  is formed to communicate with the outlet  150   b  of the second compression unit  150  to receive the fluid of the second pressure, whereas the outlet  160   b  of the second pressure chamber  160  is formed to communicate with an inlet  180   a  of the third compression unit  180  to transfer the fluid of the second pressure to the third compression unit  180 . 
         [0062]    Meanwhile, a pair of the second intercooler units  170  is disposed in the second pressure chamber  160  to face each other and cool a fluid in the second pressure chamber  160 . 
         [0063]    Although a pair of the second intercooler units  170  is disposed in the exemplary embodiment, the exemplary embodiment is not limited thereto. In other words, one, three, or more second intercooler units  170  may be used. 
         [0064]    The second intercooler units  170  may have a hexahedral shape, and the internal structure of the second intercooler units  170  may be an intercooler structure known in the art. In other words, the second intercooler units  170  have heat exchange units to lower temperature of a fluid. 
         [0065]    Meanwhile, the third compression unit  180  receives a fluid from the second pressure chamber  160  and compresses the fluid to a third pressure. The third pressure refers to pressure of a fluid compressed by the third compression unit  180  and is determined based on the second pressure described above and the performance of the third compression unit  180 . 
         [0066]    The third compression unit  180  includes a centrifugal compressor  181 . In other words, the inlet  180   a  of the third compression unit  180  is formed to communicate with the outlet  160   b  of the second pressure chamber  160  for receiving a fluid from the outlet  160   b  of the second pressure chamber  160 . On the other hand, an outlet  180   b  of the third compression unit  180  is formed to communicate with the outlet  114 . 
         [0067]    The centrifugal compressor  181  includes an impeller  181   a , a diffuser  181   b , and a scroll case  181   c , and has the general configuration of a centrifugal compressor known in the art. 
         [0068]    The impeller  181   a  includes a hub  181   a _ 1  and a blade  181   a _ 2  disposed at the hub  181   a _ 1 . The hub  181   a _ 1  is fixed to the rotation shaft  190 , and, when the rotation shaft  190  rotates, the impeller  181   a  rotates together. 
         [0069]    According to the exemplary embodiment, the third compression unit  180  includes the centrifugal compressor  181 . However, the exemplary embodiment is not limited thereto. In other words, the third compression unit  180  according to the exemplary embodiment may include a plurality of centrifugal compressors  181 . 
         [0070]    Meanwhile, the rotation shaft  190  is installed across the compressing system  100 , and is connected to the shaft of the driving motor  195 . 
         [0071]    According to the exemplary embodiment, the rotation shaft  190  is directly connected to the shaft of the driving motor  195 . However, the exemplary embodiment is not limited thereto. In other words, a separate power transmission device, such as a gear device or a belt device, may be disposed between the rotation shaft  190  and the driving motor  195  according to the exemplary embodiment. Furthermore, the rotation shaft  190  may be installed to receive a power from another driving shaft (not shown) connected to a turbine shaft (not shown) and to be rotated thereby. 
         [0072]    The rotation shaft  190  is supported to the casing  110  via a bearing  191 . The bearing  191  may be a rolling bearing, a journal bearing, an air-foil bearing, etc. 
         [0073]    The driving motor  195  produces power for rotating the rotation shaft  190 , and the control device  197  controls the driving motor  195  and the movable vane  121   c _ 1  according to a user instruction or a driving program. 
         [0074]    Meanwhile, according to the exemplary embodiment, since the first compression unit  120 , the first pressure chamber  130 , the first intercooler units  140 , the second compression unit  150 , the second pressure chamber  160 , the second intercooler units  170 , and the third compression unit  180  are disposed inside the casing  110 , the three compression units  120 ,  150 , and  180 , the two pressure chambers  130  and  160 , and the two intercooler units  140  and  170  are disposed inside the casing  110 . However, the exemplary embodiment is not limited thereto. In other words, in the compressing system the exemplary embodiment is not limited thereto, and other compression units, pressure chambers, and intercooler units may be additionally disposed inside the casing  110 . For example, the compressing system according to the exemplary embodiment may include four compression units, three pressure chambers, and three intercooler units. 
         [0075]    Furthermore, according to the exemplary embodiment, the first intercooler units  140  and the second intercooler units  170  are disposed inside the casing  110 . However, the exemplary embodiment is not limited thereto. In other words, the compressing system according to the exemplary embodiment may further include an additional intercooler unit, where the additional intercooler unit may be installed not only inside the casing  110 , but also outside the casing  110 . If an additional intercooler unit is installed outside the casing  110 , the intercooler unit and a pressure chamber are connected to each other via a pipe. 
         [0076]    Next, an operation of the compressing system  100  according to an exemplary embodiment will be described below. 
         [0077]    When a user operates the compressing system  100 , the control device  197  operates the driving motor  195 . As a result, the rotation shaft  190  rotates, and as a result the first compression unit  120 , the second compression unit  150 , and the third compression unit  180  are driven. In detail, the first rotation body  121   a  and the second rotation body  121   b  of the axial compressor  121  of the first compression unit  120  rotates, and the impeller  151   a  of the second compression unit  150  and the impeller  181   a  of the third compression unit  180  rotate. 
         [0078]    When the first compression unit  120 , the second compression unit  150 , and the third compression unit  180  are driven, a fluid flows from the inlet  113  of the casing  110  into the inlet  120   a  of the first compression unit  120 . Since the fluid is not compressed, the fluid has a relatively large specific volume. 
         [0079]    Next, the fluid is compressed to a first pressure in the first compression unit  120 . Since the first compression unit  120  includes the axial compressor  121  suitable for low-pressure compressing a large amount of a fluid having a large specific volume, the first compression unit  120  is highly efficient for compressing a large amount of a fluid having a large specific volume. Furthermore, the control device  197  controls a change of an amount of a fluid by using the movable vane  121   c _ 1  to maintain the optimal efficiency. 
         [0080]    Next, the compressed fluid moves to the first pressure chamber  130  communicating with the outlet  120   b  of the first compression unit  120 . 
         [0081]    The first intercooler units  140  are disposed in the first pressure chamber  130  and cool the fluid in the first pressure chamber  130 , thereby reducing the work of the compressing system  100 . 
         [0082]    Next, the fluid cooled by the first intercooler units  140  flows into the inlet  150   a  of the second compression unit  150  communicating with the outlet  130   b  of the first pressure chamber  130 . 
         [0083]    Next, the second compression unit  150  compresses the fluid to a second pressure. The second compression unit  150  includes the mixed-flow compressor  151  because the mixed flow compressor  151  is more efficient for compressing a fluid having a relatively small specific volume, compared to the axial compressor  121 . 
         [0084]    Next, the compressed fluid moves to the second pressure chamber  160  communicating with the outlet  150   b  of the second compression unit  150 . 
         [0085]    The second intercooler units  170  are disposed in the second pressure chamber  160  and cool the fluid in the second pressure chamber  160 , thereby reducing the work of the compressing system  100 . 
         [0086]    Next, the fluid cooled by the second intercooler units  170  flows into the inlet  180   a  of the third compression unit  180  communicating with the outlet  160   b  of the second pressure chamber  160 . 
         [0087]    Next, the third compression unit  180  compresses the fluid to a third pressure. The third compression unit  180  includes the centrifugal compressor  181  because the centrifugal compressor  181  is more efficient for compressing a fluid having a relatively small specific volume, compared to the mixed-flow compressor  151 . 
         [0088]    Next, the compressed fluid moves to the outlet  114  communicating with the outlet  180   b  of the third compression unit  180 . 
         [0089]    As described above, according to the exemplary embodiment, since the first compression unit  120  includes an axial compressor, a large amount of fluid having a relatively large specific volume may be easily compressed and the compression efficiency may be improved. 
         [0090]    Furthermore, according to the exemplary embodiment, since the first pressure chamber  130  and the second pressure chamber  160  are disposed inside the casing  110  and the first intercooler units  140  and the second intercooler units  170  are respectively disposed inside the first pressure chamber  130  and the second pressure chamber  160 , respectively, the compression work may be reduced and noise from the first compression unit  120 , the second compression unit  150 , and the third compression unit  180  may be reduced. 
         [0091]    Furthermore, according to the exemplary embodiment, since the movable vane  121   c _ 1  is installed at the axial compressor  121 , a change of an amount of a fluid may be controlled to improve the efficiency of the compressing system  100 , if necessary. 
         [0092]    Furthermore, according to the exemplary embodiment, since the first compression unit  120 , the first pressure chamber  130 , the first intercooler units  140 , the second compression unit  150 , the second pressure chamber  160 , the second intercooler units  170 , and the third compression unit  180  are disposed together inside the casing  110 , the volume of the compressing system  100  may be reduced, and convenience for assembly and maintenance of the compressing system  100  may be improved. 
         [0093]    According to the exemplary embodiment, the compressing system  100  includes three compression units  120 ,  150 ,  180 . However, the exemplary embodiment is not limited thereto. In other words, the number of compression units according to the exemplary embodiment is not limited. For example, the compressing system  100  may include a fourth compression unit and a fifth compression unit. In that case, it is desirable that the fourth compression unit and fifth compression unit are centrifugal compressors. 
         [0094]    While exemplary embodiments have been particularly shown and described above, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the inventive concept as defined by the following claims.