Abstract:
A turbine including a rotor assembly having a head adapted for engagement with a body including a passage for receipt of a fluid the passage being in communication with a flow chamber formed between the head and body on engagement of head with the body wherein the flow chamber is shaped to produce a laminar flow of the fluid out a plurality of nozzles disposed in the head.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to rotor devices and system. In particular although not exclusively the present invention relates to turbine assemblies and systems which utilise a working fluid for the generation of rotational energy. 
       BACKGROUND ART 
       [0002]    The basic operation of a conventional turbine is that expanding gases or pressurised fluids e.g. vapour stream or pressurised liquid (collectively, known as working fluids) are directed onto blades or set of blades mounted around a drum or shaft. The working fluid enters the turbine chamber where it impinges on turbine blades that are mounted around a centred shaft, causing the shaft to rotate and provide useful work. The turbine shaft work is used to drive devices such as an electric generator that may be coupled to the shaft. The shaft is typically mounted in sealed lubricated bearings on a horizontal axis that are required to be cooled to avoid lubrication failure. The energy that is not used for shaft work comes out in the exhaust as spent working fluid, so these have either a high temperature or a high velocity. The movement of the high pressure working fluid and high speed rotation of the bladed turbine create a high amount of noise. 
         [0003]    Another type of turbine used at present is the pure reaction turbine where the rotor body is mounted around a stationary working fluid inlet that is centrally located in a channel within the rotating turbine head. The rotor body is provided with peripherally mounted nozzles in fluid communication with the flow&#39;channel within the rotor body. Working fluid is introduced into the channel of this type of rotor through a centrally mounted and stationary working fluid inlet and the working fluid flows through the rotor body and out of the peripherally mounted nozzles. The nozzles are directed such that the expelled high pressure working fluid causes thrust and rotation of the rotor. As with the conventional bladed turbine, the rotor is normally coupled to a shaft in order to extract useable shaft work. 
         [0004]    One of the main issues with each of the above described turbines and rotor is that the shafts associated with the turbine and rotor, whether the shaft is the central mounting shaft for the turbine blades in the conventional turbine or the stationary working fluid channel inlet of the of the pure reaction turbine, must be supported in some manner allowing both rotation of the shafts or the rotor and also a low friction support mechanism that does not allow the escape of the working fluid. The loss of work output due to the friction can be substantial between the (i) shaft or and its support in the case of a conventional turbine or (ii) the rotor and the stationary working fluid channel inlet for the pure reaction turbine. 
         [0005]    In addition, the working fluid for both the above described turbines is limited to only one working fluid. 
         [0006]    One other problem with both types of turbines is noise emissions associated with the turbulent movement, super-sonic flow and impingement of the working fluid against the blades of the turbine as well as movement of the turbine blades for the conventional style of turbines or the super-sonic flow, and rotor arm movement of the pure reaction turbine. 
         [0007]    A further problem, particularly with the stationary working fluid inlet and the rotor configuration of the pure reaction turbine, is that the working fluid inlet and rotor need to be sealed to one another to prevent or at least reduce the amount of inlet working fluid losses from the rotor by means other than the peripherally mounted nozzles, which would reduce the turbine efficiency. One way in which this can be achieved is through a complex multi-part arrangement of rotating bearings and sealing members. The bearing-rotating seal configuration of the above described turbines requires frequent maintenance intervals. 
         [0008]    Both type of turbines have limited rotational speed by design at a given temperature and pressure of a working fluid and the rotational speed cannot be adjusted without changing the blade configuration or size with respect to conventional turbines or in the case of the pure reaction turbines the rotor arms. 
         [0009]    Clearly it would be advantageous to provide a turbine which is a capable of operation with multiple working fluids and which provides for variable rotational speed. It would also be advantageous to provide a turbine which is relatively low noise and which has reduce maintenance requirements 
       SUMMARY OF INVENTION 
       [0010]    Accordingly on one aspect of the present invention there is provided a turbine said turbine including:
       a rotor assembly having a head adapted for engagement with a body, said body including a passage for receipt of a fluid the passage being in communication with a flow chamber formed between the head and body on engagement of head with the body;   wherein the flow chamber is shaped to produce a laminar flow of the fluid out a plurality of nozzles disposed in the head.       
 
         [0013]    Suitably the resides the rotor assembly is constructed form a high temperature resistant material to enable the use of multi-working fluids of varying temperatures and pressures of the turbine. 
         [0014]    Preferably the rotor assembly includes a including a working fluid inlet member for insertion into the passage, the working fluid inlet member having a centrally located channel therethrough to allow for the injection of the working fluid into the rotor assembly. Suitably the fluid inlet member is positioned within a positive displacement rotating seal provided within the passage. The positive displacement seal member will generally be an annular member with a central bore therethrough, which is attachable to the internal cavity of the rotor body to maintain the working fluid member fluid communication with the rotor body. The seal may contain a positive displacement vane that propels working fluid back into the fluid chamber. The seal may allow a small amount of working fluid into the passage to lubricate the rotor assembly. 
         [0015]    The rotor assembly may be supported in its rotation by the fluid inlet member through its interface with the positive displacement rotating seal. The working fluid inlet member may stationary with the rotor body rotating thereon. The working fluid inlet member may contribute to the support of the rotor body in position. In a most preferred embodiment, the rotor body may be suspended from the working fluid inlet member and supported by a shaft sea assembly. 
         [0016]    The rotor may include a spring loaded seal member. Suitably the spring loaded seal member is positioned adjacent the bottom of the rotor body and associated with the positive displacement rotating seal to prevent escape of the working fluid. Suitably the spring loaded seal assembly is in overlapping relation with a portion of the positive displacement rotating seal. This second seal member will preferably be of a type known as spring loaded seal. The spring loaded seal member may have at least one radial channel therein. Located within the radial channel will typically be a spring loaded high temperature self-lubricating plastic ring style seal assembly. The ring seal assembly will generally be multipart in order to allow for the expansion and contraction if the seal assembly during rotation. 
         [0017]    The outer surface of the working fluid inlet member and a relatively located surface of the seal assembly or seal members may be provided with correspondingly shaped portions allowing the working fluid inlet member and the seal assembly to seal against one another but also allowing the seal assembly to rotate and be affected by centrifugal forces caused by such rotation. 
         [0018]    Suitably the flow chamber is shaped to produce a laminar flow through the head. Preferably the chamber is contoured so as to reduce turbulence within the flow of the working fluid. The nozzles may be coupled to the flow chamber via contiguous contoured ejectors that reduce air resistance upon rotation and attribute to the noise reduction associated with breaking and collapsing air. Preferably the ejectors are located tangential to the laminar flow chamber. 
         [0019]    The nozzles preferably are arranged in sets of opposing nozzles pairs. preferably the head of each nozzles is adjustable and may be throttled to produce a desired flow rate between a closed and fully open position. Suitably the nozzle heads are positioned so as to terminate within or adjacent the circumference of the rotor head. 
         [0020]    The rotor head may be coupled to an output shaft. The output shaft will typically be associated with an alternator in power production applications otherwise to drive-shaft propelling any land, marine and air transport vehicle or any stationary object that requires rotational work. The output shaft will generally be cylindrical and elongated. It will typically be centrally mounted in relation to the rotor body and generally opposite the working fluid inlet member. The output shaft may typically be supported by one or more seals which may be similar in configuration to those which seal the working fluid inlet member to the rotor body. 
         [0021]    Suitably the rotor assembly is mounted between a pair of support plates. The support plates may be coupled together via a series of support rods. The plates may, be constructed form any suitable high temperature resistant material. 
         [0022]    The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0023]    In order that this invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings, which illustrate preferred embodiments of the invention, and wherein: 
           [0024]      FIG. 1  is a sectional side elevation view of a rotor assembly for use in a turbine according to one embodiment of the present invention; 
           [0025]      FIG. 2  is a plan cross sectional view of the rotor head for use in the rotor assembly of  FIG. 1 ; and 
           [0026]      FIG. 3  is a schematic view of the rotor assembly moulted in situ within a steam turbine system. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0027]    With reference to  FIG. 1  there is illustrated one possible configuration for a rotor assembly  100  according to one embodiment of the present invention. As shown the rotor assembly  100  in this instance includes a rotor mechanism  101  disposed between support plates  102   1 ,  102   2 . The plates in this example may be coupled together via a set of support rods which are fixed to each plate through apertures  103  thereby retaining the rotor mechanism  101  between the plates  102   1 ,  102   2 . 
         [0028]    The rotor mechanism  101  in this case includes head  104  and body  105 . The head  104  is secured to the body  105  via the use of suitable fasteners inserted through apertures  106  to form a fluid tight seal between the head  104  and body  105 . As shown the body  105  includes a passage  107  for receipt of a fluid inlet member  108  for injection of a working fluid into the head  104  of the rotor. The fluid inlet member  108  in this case is inserted into the passage  107  through inlet fixture  109  disposed in plate  102   2 . The inlet fixture  109  preferably includes an aperture  110  for the insertion of a grub screw or other such suitable fastener to retain the fluid inlet member  108  in position. 
         [0029]    To prevent backflow release of the working fluid from the rotor head  104  a section of the fluid inlet  108  abutting the rotor head is retained within a rotary seal  111  disposed within passage  107 . As can be seen the rotary seal  111  in this finishes sustainably flush with the base of body  105  which is set above the inlet fixture  109  such that body  105  is free to rotate on the rotatory seal  111 . The rotary seal  111  in this instance contains a spiral vain which directs working fluid flow upwards toward the head  104  to reduce the potential for back flow of the working fluid through passage  107 . To further reduce the potential release of the working fluid from the head  104  a ring seal  112  is provided. As shown the ring seal  112  overlaps a portion of the rotary seal  111  adjacent the base of body  105  and is held against the upper surface of the inlet fixture  109  via spring  113 . As will be appreciated by those of skill in the art this particular arrangement enables the body to rotate on the seals  111  and  112 , however the body of the rotor could be bearing mounted with respect to the inlet fixture  109 . 
         [0030]    As noted above the rotor head  104  is fixed in sealing relation to the rotor body  105  The rotor head in this example is shape such that on engagement with the body forms a laminar flow chamber  114  which distributes the working fluid evenly to nozzles  115  which are disposed positioned tangential to the laminar flow chamber  114 . The specific arrangement of the nozzles  115  is discussed in greater detail below with respect to  FIG. 2 . As shown the upper end of the head  104  includes a shaft  116  which extends beyond plate  101   1  to enable the rotational energy of the rotor to be harnessed. As shown in this particular example the shaft  116  is positioned within mounting member  117  positioned within plate  101   1 . 
         [0031]    In this instance the mounting member  117   2  may be a rotary seal member similar to that of seal member  111  and is position against the upper face of the head  104 . In such cases the shaft  116  is frictionally positioned within the mounting member  117  and is free to rotate within the seal member  117 . While in the present example a friction mounting is utilised but it will be of course be appreciated by those of skill in the art the shaft could be bearing mounted within the mounting member  117  and/or support plate  101   1 . 
         [0032]    In the present example the rotor  100  is designed to operate on the principle of expansion of working fluid from a high pressure environment to a low pressure environment outside the rotor to produce mechanical work. More specifically as a working fluid is fed to the rotor at an elevated pressure and/or temperature. As the working fluid flows through the rotor body  105  it enters the laminar flow chamber  114  within head  104 , the fluid is then distributed via the laminar flow chamber  114  out of the nozzles  115 . As the environment outside the head  104  is at a lower pressure and/or temperature than that of the working fluid filling the chamber  114  the resultant pressure differential along with the nozzle  115  size shape etc. causes the fluid to be ejected in as a high pressure stream thereby producing a driving force for the rotor. 
         [0033]    While in the above discussed example it is desirable to prevent back flow of the working fluid from the laminar flow chamber  114  to ensure maximum utilisation of the potential energy of the fluid it will of course be appreciated by those of skill in the art that depending on the fluid utilise a small amount of seepage may into the body  105  and passage  107  about the seal  111  may be desirable. For example where the fluid is steam or a liquid the back flow of a small amount of fluid may be utilised to wet the passage  107  to thereby lubricate the rotor assembly  100 . 
         [0034]      FIG. 2  depicts the construction of the head  104  in further detail. As shown the head  104  includes a plurality of nozzles  115 . As can be seen the nozzles  113  are arranged in opposing nozzle sets with each nozzle  115  being coupled to the laminar flow chamber  114  in a contiguous manner via an ejector tubes  118 . The ejector tubes  118  in this example are disposed substantially tangential to the laminar flow chamber  114  (i.e. outer most edge of ejector tube is tangential to the circumference of the laminar flow chamber) so as to extract the maximum amount of thrust through each nozzle  115 . 
         [0035]    As can be seen in this instance the nozzles  115  include an adjustable head  119 . The heads  119  can be adjusted to vary the rotational speed of the rotor. For example one or more of the nozzles could be open or closed or partially open (throttled) to vary the output of the working fluid and thereby adjust the working speed of the rotor and as a result the effective output power of the rotor. 
         [0036]    As shown in  FIG. 2  the rotor head is shaped in a manner so as to limit the amount of protrusions of the rotating part to assist in the noise reduction when in operation. More specifically the nozzles  115  are positioned such the heads  119  of each nozzle  115  terminate on or within the circumference of the rotor head  104 . In addition to the reduction of noise produce by the rotor the positioning of the nozzles  115  in this manner also reduce drag on the rotor. 
         [0037]    With reference to  FIG. 3  there is illustrated one possible configuration of a system for the production of mechanical utilising the rotor of  FIGS. 1 and 2  above. The rotor in this example is configured operation with steam as the working fluid. It will be appreciated by those of skill in the art that the interconnection high pressure steam and the provision of additional fluid to the boiler requires the use of various auxiliary components such as pumps check valves relieve vales etc. and that for the purposes of clarity of description and the figures the use of these components is not discussed or shown. 
         [0038]    As shown the rotor  100  in this instance is positioned within a housing  200 . The fluid inlet member  108  is connected to boiler  201  enabling steam to be injected through the fluid inlet member  108  into the laminar flow chamber  114 . The boiler  201  may be any suitable boiler such as a gas fired boiler, electric boiler, solar boiler etc. As the steam produced by the boiler is fed into the laminar flow chamber  114  it is ejected through ejector tubes  118  out nozzle head  119  causing the rotation of the rotor driving shaft  116 . 
         [0039]    As the steam is expelled form the rotor head  104  it fills the housing  200  the expelled steam may then be drawn off from the housing  200  to condenser  202  via line  203 . The extracted steam is then recondensed and returned to the boiler  201 . It will of course be appreciated by those of skirl in the art that the condenser  202  in this instance need only provide sufficient cooling of the vapour to cause the phase transition back to liquid, there is no need for the condenser  202  to significantly cool the condensate before it return to the boiler. Indeed by not cooling the condensate prior to it return places less strain on the boiler due to the decreased temperature differential between the water in the boiler and the return feed. 
         [0040]    Additional as the steam is expelled from the rotor it loses both pressure and temperature this cause some of the steam to recondense inside the housing this condensate can be extracted via line  204  and returned directly to the boiler. 
         [0041]    In the above examples the rotor assembly  100  of the invention is depicted as being vertically mounted and rotating about a central vertical axis. As such the various components of the rotor are located about a central axis to allow balanced rotation and reduced wear on moving parts. It will of course be appreciated by those of skill in the art that while the above examples depict the rotor mounted for vertical operation the rotor could mounted horizontally without any substantive impact to its operation. 
         [0042]    It is to be understood that the above embodiments have been provided only by way of exemplification of this invention, and that further modifications and improvements thereto, as would be apparent to persons skilled in the relevant art, are deemed to fall within the broad scope and ambit of the present invention described herein.