WO2022150908A1

WO2022150908A1 - Expansion rotary device and method

Info

Publication number: WO2022150908A1
Application number: PCT/CA2022/050032
Authority: WO
Inventors: Dustin Clark
Original assignee: Dustin Clark
Priority date: 2021-01-12
Filing date: 2022-01-11
Publication date: 2022-07-21

Abstract

A rotary expansion device, system, and method for use in the field of energy conversion devices, and more specifically to devices that convert pressure energy into mechanical and/or electrical energy. The rotary expansion device having a rotor receiving a gas centrally within the rotor; at least one expansion port in the rotor expelling the gas at an exit velocity from an outer surface of the rotor; a stator receiving an expelled gas; and the exit velocity of the expelled gas imparts a rotational velocity to the rotor. The system having a plurality of rotary expansion devices.

Description

EXPANSION ROTARY DEVICE, SYSTEM, AND METHOD

FIELD

[0002] This invention is in the field of energy conversion devices, and more specifically to devices that convert pressure energy into mechanical and/or electrical energy.

BACKGROUND

[0003] Current expansion devices suffer from drawbacks and restraints. Turbine devices create high velocity low-pressure gas streams which are subject to flow related issues. Gas condensing into liquid hampers all current expansion devices, causing damage to components and negatively impacting efficiency. Various common expansion devices will be described and the associated limitations with each device.

[0004] Impulse turbines function with both liquid and gas designs. An expansion from high pressure gas to a low pressure gas occurs across one or more nozzles creating a high velocity flow. This high velocity flow is directed on a bladed wheel turbine design. The force of the high velocity drives the wheel to turn creating rotational mechanical energy. The high velocity stream causes a number of issues. The high velocity stream created by the gas expansion can create a shockwave and/or a turbulence that results in vibration issues as the turbine blades pass through the stream. Condensation during the expansion creates high velocity liquid droplets to impact the blades of the turbine causing damage. Fluid accumulation can also greatly impact the efficiency of the turbine.

[0005] Reaction turbines are used today in many forms of steam power generation, such nuclear and coal power generation. Reaction turbines take a high-pressure gas stream and flow the stream across multiple stages of expansion. Each stage of expansion is specifically designed for a specific pressure drop requiring component changes such as blade sizing and shape otherwise an efficiency of the expansion process is impacted. These turbines cannot fully condense the gas. Condensation on one or more blades of the turbine cause damage and efficiency related issues. These turbines are also difficult to scale down as flow characteristics create losses as the size decreases. A surface area of the contact between the gas and the non-working components, such as piping, of an expander increase as the size decreases. This increase in surface area creates friction and impacts the overall efficiency of the machine.

[0006] Turbo expanders create a high velocity gas stream and have some similar characteristics to impulse turbines. One difference is that turbo expanders has one large inlet nozzle and the turbine blade is perpendicular to the flow of the high velocity gas stream. The design corkscrews the gas creating rotational energy. This design also suffers from turbulence and shockwaves from the high velocity gas stream. The force of the gas exerting on the rotor blades causes a high level of thrust which requires expensive and advanced bearing design. Condensation in the high velocity jet stream can cause major issues on the rotor blades as the fluid creates drag and vibrations across the blades damaging both the blades and the bearings. Fluid accumulation also causes efficiency issues. [0007] Reciprocating expansion devices may also be called piston driving expansion devices. Examples include old steam engines, pneumatic tools, and diaphragm pumps. These devices do not have issues associated with creating high velocity jet streams but can be quite complicated as linear stroke design requires complex valving and associated crankshaft linkage to convert to work into continuous rotational mechanical energy. Similar to the other designs, condensation and fluid accumulation create efficiency issues as fluid hampers flow characteristics of the low-pressure gas through valving and similar piping. The condensation can also cause damage to components and create vibration issues.

SUMMARY

[0008] The invention herein may comprise the aspects as described herein in any and/or all combinations.

[0009] According to an aspect, there is provided a rotary expansion device having comprising: a rotor receiving a gas centrally within the rotor; at least one expansion port in the rotor expelling the gas at an exit velocity from an outer surface of the rotor; a stator receiving an expelled gas; and the exit velocity of the expelled gas imparts a rotational velocity to the rotor. The rotor may rotate at the rotational velocity regulated by a rotor pressure of the gas relative to a stator pressure. The exit velocity may match the rotational velocity of the rotor. The rotor may comprise one or more short ends and one or more long edges alternating around a perimeter of the rotor and forming the one or more expansion ports. Each of the expansion ports may have a converging section and a diverging section. The converging section and the diverging section may be separated by a throat near which the gas reaches a maximum flow rate. The maximum flow rate may reach a supersonic velocity determined by at least one specific property of the gas. A centrifugal compression due to the rotational velocity of the rotor may provide additional pressure between the converging section and the diverging section. The diverging section may determine the exit velocity from the expansion ports. A pressurized pipe may provide the gas to the rotor. The pressurized pipe may be rotatably coupled to the rotor.

[0010] The stator may comprise one or more stator fins protruding towards the rotor; and receiving the expelled gas. The stator fins may inhibits the expelled gas from forming a rotational flow. Each of the stator fins may have a long edge and a short edge.

[0011] The rotor may have two or more layers comprising a plurality of the expansion ports. The plurality of the expansion ports on each of the layers may be staggered vertically.

[0012] The rotary expansion device may further comprise a generator producing electrical energy from the rotor.

[0013] The gas may be condensed to produce condensation.

[0014] According to another aspect, there is provided a rotary expansion system having a plurality of the expansion rotary devices.

[0015] According to yet another aspect, there is provided a method of producing a rotational motion of a rotor. The method may receive a gas along a central axis within the rotor; expel the gas at an exit velocity via at least one expansion port in the rotor; receive the expelled gas by a stator; and rotate the rotor at a rotational velocity. DESCRIPTION OF THE DRAWINGS

[0016] While the invention is claimed in the concluding portions hereof, example embodiments are provided in the accompanying detailed description which may be best understood in conjunction with the accompanying diagrams where like parts in each of the several diagrams are labeled with like numbers, and where:

[0017] Figure l is a conceptual illustration a gas exiting an expansion port of a rotor;

[0018] Figure 2 is a top perspective cutaway view of the expansion rotary device;

[0019] Figure 3A is a top cross-section view along A-A of the expansion rotary device having a tight clearance between the rotor and a stator; [0020] Figure 3B is a side cross-section view of the expansion rotary device;

[0021] Figure 4A is a top cross-section view along B-B of the expansion rotary device having a loose clearance between the rotor and the stator;

[0022] Figure 4B is a side cross-section view of the expansion rotary device;

[0023] Figures 5 and 6 are side cross-section views of an expansion port of the rotor; [0024] Figure 7 is a three-dimensional perspective rendering of an internal structure of the rotor with the body of the rotor removed to more clearly observe the expansion ports of the rotor

[0025] Figures 8 A and 8B are a top cross-section view along E-E of Figure 8C and a side crosssection view along F-F of Figure 8C of an airflow within the rotor of the expansion rotary device;

[0026] Figure 8C is a side cross-section view of the expansion rotary device; [0027] Figure 9A is a side cross-section view of the expansion rotary device;

[0028] Figure 9B is the external view of the expansion rotary device of 9A;

[0029] Figure 10A is a side cross-section view of the rotor of the expansion rotary device;

[0030] Figure 10B is a cross-section view of another embodiment of the expansion rotary device; [0031] Figure 10C is an exploded view of the expansion rotary device;

[0032] Figure 11 shows the exploded view of the expansion rotary device with built-in electrical power generation;

[0033] Figure 12A and 12B are a side cross-section view and a front cross-section view of multiple expansion rotary devices operating in parallel; [0034] Figures 13 A and 13B are a front view and a side cross-section view of the expansion port of the rotor of the expansion rotary device;

[0035] Figures 14A and 14B are a front view and a side cross-section view of multiple layers of expansion ports of the rotor of the expansion rotary device;

[0036] Figures 14C and 14D are top cross-section views of the multiple layers of expansion ports of the rotor of the expansion rotary device

[0037] Figure 14E depicts a perspective view of the expansion ports of the rotor of the expansion rotary devices in a side-by-side comparison with the body of the rotor removed for clarity

[0038] Figure 15 is a top cross-section view of the rotor having inserts for the expansion ports; [0039] Figures 16 and 17 are top cross-section views of stators having different numbers of fins therein;

[0040] Figures 18 A and 18B are top perspective views of the stator having replaceable fins therein;

[0041] Figures 19A and 19B demonstrate a cylindrical stator (Fig. 20A) and a tapered stator (Fig. 20B);

[0042] Figures 20A and 20B show a top view and a side view of a stator support cage;

[0043] Figures 21A to 21C are side cross-section views of the tapered stator showing variable clearance between the rotor and the stator;

[0044] Figure 22A is a perspective view of a two expansion port rotor; [0045] Figure 22B is a top cross-sectional view along B-B of the two expansion port rotor;

[0046] Figure 22C is a side view of the two expansion port rotor;

[0047] Figure 22A is a perspective view of a three expansion port per layer rotor;

[0048] Figure 22B is a top cross-sectional view along A-A of the three expansion port per layer rotor; [0049] Figure 23C is a side view of the three expansion port per layer rotor;

[0050] Figures 24A and 24B show a side cross-sectional view and a top cross-sectional view of inlet blades of the rotor of the expansion rotary device; and

[0051] Figure 25 depicts a centrifugal compression within the rotor of the rotary expansion device. DETAILED DESCRIPTION

[0052] The aspects described herein and understood by a person skilled in the art generally convert a pressure energy into a mechanical energy, which may be converted into an electrical energy. The aspects may take a high-pressure gas stream and may expand the high-pressure gas to a lower pressure. The expansion of the high-pressure gas may convert the pressure energy into useful rotational mechanical energy. The aspects herein may be used across multiple industries including, but not limited to, power generation, refrigeration, and/or oil and gas. The aspects herein may overcome one or more issues with the current expansion technology.

[0053] A rotary expansion device 200 as described herein with reference to the figures may eliminate or reduce a use of a high velocity jet stream of a low-pressure gas. A high velocity jet stream may create shockwave and/or turbulence issues. Condensation in the high velocity jet stream may create high velocity liquid droplets that may cause damage to components. The high jet stream may have a tendency to flow around one or more blades of the turbine instead of performing work and may result in efficiency losses. The high velocity jet stream may reduce the ability to appropriately size the pressure energy to mechanical energy system. To induce the high velocity jet stream, a piping-to-gas surface area may be reduced to a sufficient level or friction losses may greatly inhibit the function and efficiency of the pressure energy to mechanical energy system.

[0054] The rotary expansion device 200 as described herein may expand multi-component gas streams and may eliminate condensation-related impediments and/or efficiency issues. The rotary expansion device 200 may incorporate one or more rugged components, including one or more large stable bearings, a small number of moving parts, and/or easy replacement/repair of components. The rotary expansion device 200 may be durable, simple, and/or efficient across a wide spectrum of operating conditions including, but not limited to, gas condensation.

[0055] The rotary expansion device 200 as described herein may introduce a high pressure gas into a rotor 110 thereby determining a rotor pressure within the rotor 110. An expansion of the high pressure gas may take place through one or more expansion ports 112 extending from a central conduit 702 through a body of the rotor 110 to an outer surface of the rotor 110. The expansion through the one or more expansion ports 112 may create a rotational energy. A stator 220 may have a finned housing that may maintain a low-pressure gas (at a stator pressure) stationary to prevent a swirling gas that may inhibit efficiency. The flow of the gas may be any orientation, but a vertical downward flow may allow any condensation and associated fluid to flow away from the rotor by way of gravity thereby reducing any adverse effects.

[0056] In some of the aspects described herein, the rotational energy may be transferred via a shaft 710 to a generator, but this should not be considered limiting, just as an example configuration. This new expansion rotary device 200 can be configuration to do any applicable shaft work.

[0057] FIG. 1 is a conceptual illustration a gas 102 exiting an expansion port 112 of a rotor 110 as the rotor 110 turns. The gas 102 leaving the expansion port 112 of the rotor 110 through a throat 508 may maintain a rotational velocity of the rotor 110. The gas 102 may exit the expansion port 112 with an exit velocity of approximately 500-ft/s relative to the rotor 110. A stator 220 (not shown in FIG. 1, but introduced in FIG. 2) may comprise a low-pressure gas region 104 where the gas 102 leaving the expansion port 112 may have an exit velocity of O-ft/s relative to the low- pressure region 104. The velocities herein are for illustrative purposes only and should not be considered limiting. [0058] Turning to FIG. 2, the rotary expansion device 200 is shown in more detail. The rotary expansion device 200 may comprise the rotor 110 configured to rotate within a stator 220. A protective cylindrical housing 230 may enclose the stator 220 and the rotor 110. In this aspect, the stator 220 may be cylindrical in shape. A high-pressure gas may enter the rotary expansion device 200 through a high-pressure pipe 202. In some aspect, the high-pressure gas may flow from one inlet along the central axis of the pipe 202 or may be configured to flow from one or more dual inlets along the central axis of the rotary expansion device 200. The pipe 202 may be fixedly coupled to the rotor 110 in which case, the pipe 202 may rotate with the rotor 110. In another aspect, the pipe 202 may be rotatably coupled to the rotor 110 allowing the rotor 110 to rotate around an axis of the pipe 202. A connection between the pipe 202 and the rotor 110 may be sealed with one or more seals (not shown). In this aspect, the rotor 110 rotates in a clockwise rotation within the stator 220. In another aspect, the rotor 110 rotates in a counter-clockwise rotation within the stator 202. In some aspects, the rotation of the rotor 110 may be reversed. In operation, the rotor 110 may rotate at a rotational velocity 210 of approximately 500-ft/s around a central axis. In some aspects, the rotational velocity 210 may be adjusted.

[0059] The rotational velocity may be controlled through regulating the pressure in the pipe 202 supplying an interior of the rotor 110. At a throat (e.g. smallest point) of the expansion port 112, the high-pressure gas (e.g. expelled gas) may reach a maximum flow rate at or near Mach 1 and may vary dependent on a type or composition of gas, pressure, and/or temperature. The gas becomes incompressible at the Mach 1 speed and cannot increase in flow velocity past this speed at high pressure. The number of expansion ports 112 along with the respective size of the throats of these ports 112 may determine mass flow at a set pressure supplied by the pipe 202. An orifice, nozzle, or expansion port 112 may be sized to match this optimal mass flow. At the throat calculated by a low pressure exit velocity of the gas. Using convergent/ divergent nozzle on a rotary plane, isentropic expansion calculations may be employed to determine an exit volume and the velocity of the low-pressure gas. The isentropic expansion calculations may be used in determining a tapered increasing dimensions of the expansion ports 112 following the throat 508 to the expansion ports exit. At this supplied mass-flow and downstream lower-pressure, the sizing of the exit port 112 may correspond to higher than or equal to Mach 1 velocities for this gas at the higher- volume lower-pressure downstream side of the throat for maximum efficiency. The rotational velocity 210 may be determined by the exit velocity of the gas from the rotor 110 as the theoretical rotor speed if no work is removed. The gas may be generating constant thrust therefore doing work on the rotor 110. A shaft 710, when attached to a generator or other device, may remove a specific amount of mechanical work at a desired rpm. The exit velocity may be determined to correspond to a desired rotations-per-minute (rpm) of the rotor 110. For example, a 2-pole generator may achieve 3600-rpm for 60Hz. The low-pressure side of the expansion port 112 may be determined by ensuring that the exit velocity of the gas corresponds to a selected rotational velocity to achieve the corresponding rpm. The mass flow out of the gas leaving the rotor 110 and the gas’s corresponding exit velocity may determine the energy available for work. A difference between the gas’s exit velocity and the speed of the rotor 110 may determine how much mechanical work may be performed by the rotor 110.

[0060] The high-pressure gas within the pipe 202 may enter the rotor 110 and may exit one or more expansion ports 112 producing a flow out of the expansion ports 112. The flow from the expansion ports 112 may impart a force on the rotor 110 thereby causes the rotational velocity 210. The expansion ports 112 may be round, oval, or rectangular and/or may be located on a periphery of the rotor 110 with an exit thrust at a tangent angle to the rotor 110. In some aspects, the expansion ports 112 may be trapezoidal or comprise one or more curved edges. The rotor 110 may have any number of expansion ports 112. In this aspect, the expansion ports 112 may be formed from one or more rotor fins 250 as further described in detail below.

[0061] Any condensation (not shown) from a change in pressure from an interior of the rotor 110 and an exterior of the rotor 110 through the expansion ports 112 may fall away from the rotor 110 via gravity and/or the flow from the expansion ports 112. In this aspect, the liquid condensation may fall towards a bottom of the housing 230 where the condensation may be collected in an accumulation vessel 1206 and/or exhausted from the housing 230. In other aspects, the supplied air may be free of moisture resulting in no condensation. In other aspects the supplied gas, whether singular or multi component, may have no component gas within the pressure and temperature range for condensation resulting in no liquid accumulation.

[0062] When the high pressure gas is first introduced to the rotor 110, the flow exiting the one or more ports 112 may have a high velocity relative to the rotor and/or relative to a low pressure gas within the stator 110. As the rotor 110 increases in rotational velocity (e.g. rpm) from the expansion of the high-pressure gas through the ports 112, the high-velocity low-pressure gas exiting the rotor may have a lower relative velocity to the low pressure gas within the stator 110. In this aspect, the rotational velocity 210 of the rotor 110 may match the exit velocity of the low pressure gas exiting the ports 112 but with an opposite direction (e.g. the rotational velocity 210 plus the exit velocity equals approximately zero ft/s). A matching of the rotational velocity 210 and the exit velocity reduces or eliminates shockwaves and/or turbulence within the stator 220.

[0063] By moving the point of the expansion and/or force generation to the outside of the rotor 110, efficiency losses due to high velocity friction and/or turbulence may be limited. Also, moving the point of the expansion and/or force generation may also reduce and/or eliminate problems associated with shockwaves and/or vibration. The liquid droplets may also have less velocity and therefore may not damage components. The problems associated with the liquid droplets and accumulation may also be further reduced by orienting the expansion rotary device 200 in a vertical downward flow.

[0064] The aspects described herein may result in less complex computational flow dynamics as orifice flow and expansion calculations may be used. The sizing of the rotor 110 and/or the sizing of the expansion ports 112 may be determined by a power requirement and/or a specified rotational velocity (rpm).

[0065] Turning to FIGS. 3 A and 4A, a cross-sectional top view of the rotor 110 and the stator 220 is presented based on the cross-sections presented in FIG. 3B and 4B respectively. In this aspect, the rotor 110 has three layers 2302 of ports 112. Each of the layers 2302 may comprise four rotor fins 250 corresponding to four ports 112 per layer 2302 (twelve ports 112 in total). Only one of the layers 2302 may be described but the other layers 2302 may be similar or the same as the layer 2302 described herein. Each of the four rotor fins 250 generally has a short edge 252 and a long edge 254. The short edge 252 may be generally perpendicular to an adjacent long edge 254 at or near the central conduit 702. The short edges 252 and the long edges 254 alternate between each other around a perimeter of the rotor 110 for each layer 2302. In this aspect, the rotor 110 rotates in a counter-clockwise direction 210.

[0066] An interior of the stator 220 may have one or more stator fins 310 protruding towards the rotor 110. In this aspect, twelve of the stator fins 310 are present around the interior of the stator 220. Similar to the rotor 110, the stator fins 310 may each have a long edge 312 and a short edge 314. The stator fins 310 may be shaped in order to inhibit the low-pressure gas in order to reduce and/or eliminate any swirling and/or rotational flow of the low-pressure gas. The stator fins 310 may be varied depending on the design requirements. The gas expansion at the exit of the expansion port 112 may account for a distance to the stator fins 310 and walls. When the clearance is too tight, a higher than desired exit velocity (and corresponding rotational velocity 210) may result. When the clearance is too loose, a lower than desired exit velocity (and corresponding rotational velocity 210) may result. The expansion ports 112 may not be in a same position as the stator fins 310. The stator fins 310 may be spaced such that each expansion port 112 is on a different section of the stator fins 310 in order to reduce and/or eliminate vibration and pulsation. If multiple ports 112 reach the same position on the stator fins 310 vibration and/or pulsation may occur.

[0067] As previously described, the rotational velocity 210 of the rotor 110 may be imparted on the rotor 110 by the expanding gas exiting each of the four ports 112. As shown in FIG. 3 A, when a fin peak 324 on the exterior of each of the rotor fins 250 is aligned with a fin peak 326 of one of the stator fins 310, the expanding gas exiting the four ports 112 expands along the long edges 312 of the stator fins 310. As shown in FIG. 4A, when the expanding gas reaches the short edges 314 of the stator fins 310, the expanding gas may be dampened by the short edges 314 thereby reducing and/or eliminating any swirling and/or rotational flow of the low-pressure gas.

[0068] As demonstrated in FIG. 3 A and 4A, the same rotor 110 may be used within different types of stators 220. For example, in FIG. 3 A, the stator 220 comprises twelve stator fins 310 that alternate between straight short edges 314 and curved or arcuate long edges 312. In another example of FIG. 4A, the stator 220 comprises six stator fins 310 with straight short edges 314 and flatter long edges 312 when compared to the example in FIG. 3 A. [0069] Turning to FIGS. 5 and 6, a side cross-sectional view of the expansion port 112 is shown for one of the rotor fins 250. The high-pressure gas (demonstrated by the closely packed circles) may be provided to an interior side 504 of the expansion port 112 by the pipe 202. A restriction or nozzle 502 may further cause an increase to the pressure of the high-pressure gas exiting the expansion port 112 thereby increasing the velocity of the exiting and expanding gas 506. In this aspect, the nozzle 502 may have a narrower opening 508 (e.g. throat) on the interior side 504 and a wider opening 510 on the exterior side 512. The exiting gas 506 may cause motion of the expansion port 112 in a direction opposite the exiting gas 506. In the aspect shown particularly in FIG. 5, the narrow opening 508 may comprise a protrusion into the expansion port 112. In the aspect shown particularly in FIG. 6, the narrow opening 508 may taper to become gradually wider from the interior side 504 to the exterior side 512. Other aspects demonstrated with particular reference to FIG. 7 demonstrate a particular example of an internal structure of the expansion ports 112.

[0070] As shown in FIG. 7, the internal structure of the expansion ports 112 of FIG. 3 are shown with the body and fins 250 of the rotor 110 removed to improve clarity. The central conduit 702 or inlet receives the high pressure gas flow central to the rotor 110. The high pressure gas may then flow into a convergent section 704 which then narrows to the throat 508 accelerating the gas to at or near Mach 1. The accelerated gas may then enter an expanding divergent section 708 and may result in further acceleration as the gas gains volume and decreases pressure. Once the gas reaches the expansion port opening 112, a maximum desired exit velocity may be reached. The maximum exit velocity may be designed to higher than Mach 1 and/or allow for the lower-pressure, high-velocity gas to be fully expanded to the lower stator pressure and/or may allow for high isentropic efficiency be reached as the gas exits the expansion port opening 112. [0071] At a bottom of the central conduit 702 may be a base 712 (shown more clearly in FIG. 9B) that may be coupled to a shaft 710 at the center of the rotor 110. In this aspect, the rotor body may be enclose and may couple the rotor fins 250 to each other. One or more inlet blades 704 may extend from the base 712 to the ports 112 in order to form an interior wall of the port 112. The inlet blades 704 may also be shaped to further compress the gas to the ports 112. In other aspects, the central conduit 702 may be rotatably coupled to the pipe 202.

[0072] FIGS. 8 A and 8B show cross-section views shown in FIG. 8C depicting an airflow pattern through the rotor 110. FIG. 8 A demonstrates an airflow generally from a central axis in the central conduit 702 in the rotor 110 towards the ports 112. When viewed from the side in FIG. 8B, the airflow progresses towards the rotor base 712 whereby the airflow may be directed towards the ports 112. The high-pressure gas within the rotor 110 flows through the expansion ports 112 thereby reducing the pressure of the exiting gas and increasing the velocity. When the rotor 110 reaches a high rotational velocity, an inertia of the high-pressure gas within the rotor 110 may further compress the high-pressure gas at the expansion port 112. The compression at the expansion port 112 due to the high rotational velocity of the rotor 110 may provide further rotational force on the rotor 110 from the exiting gas from the expansion port 112. The compression may also reduce friction losses present in the previous pressure devices.

[0073] A particular aspect may be shown in FIGs. 9A to 12B with additional details presented. A high pressure gas supply 1002 may be provided via a pipe that may supply one or more of the expansion rotary devices 200 (as described below with reference to FIGs. 12A and 12B). The high pressure gas supply 1002 may be throttled through a control valve 1004 that may provide a flow control and/or a pressure control of the gas supplied via the supply pipe 202. The control valve 1004 may be a throttling device to regulate the flow and the pressure to the rotor 110. As previously described, the rotor 110 expands the high-pressure gas through the expansion ports 112 resulting in the rotational velocity of the rotor 110 on the shaft 702. During a startup, a reduced flow rate may be advantageous to bring the rotor 110 up to speed gradually. This gradual speed increase may limit any high velocity flow out of the exhaust ports 112 that may damage the stator 220.

[0074] In this aspect, the shaft 710 may be coupled to the rotor base 712. A seal and bearing assembly 1112 may be placed on the shaft 710 where the shaft 710 exits the low-pressure chamber 1006. The stator 220 holds the high-velocity, low-pressure gas static with the one or more stator fins 310 (not shown in FIG. 9 A for clarity).

[0075] In this aspect, a low-pressure chamber 1006 of the housing 230 may have one or more upper-tapered flanges 1008 and one or more lower-tapered flanges 1010. The upper-tapered and lower-tapered flanges 1008, 1010 may be held together using one or more studs, bolts, and/or other fastener. The flanges 1008, 1010 may permit the rotary expansion device 200 to be disassembled for maintenance.

[0076] Further aspects of the rotor 110 may be seen in the cross-sectional views of FIGs. 10A to 10C. As previously described, the rotor 110 may have one or more expansion ports 112 and rotate within the stator 220. One or more back bearings 1102 may provide stability between the rotor 110 and the high-pressure inlet pipe 202. The inlet pipe 202 may function as a stationary hub for the rotor 110 to spin on. One or more torque bolts 1104 may secure an upper portion 1120 of the rotor 110 to a main inlet body 1110 of the rotor 110. Removal of the torque bolts 1104 may allow removal of the main inlet body 1110 from the upper portion 1120 of the rotor 110. The upper portion 1120 may rotatably secure the rotor 110 to a flange 1124 at the opening of the pipe 202. The flange 1124 may be secured to the pipe using one or more torque bolts, threads, or other method of precision unification 1122.

[0077] An interface between the inlet pipe 202 and the rotor 110 may be machined for securing bearings and seals therebetween. One or more large bearings 1106 may handle the mass and rotational forces between the rotor 110 and the pipe 202. One or more pressure seals 1108 may prevent the high-pressure gas from migrating into the low-pressure chamber 1006. The pressure seals 1108 may be capable of handling a pressure differential between a high pressure within the main inlet body 1110 and the low-pressure chamber 1006 as well as the rotational friction. The main bearings 1106 may be large and under a relatively constant strain. The second back bearings 1102 may further increase a stability of the rotor 110.

[0078] At the rotor base 712 may be a coupler 1112 for receiving the shaft 710. A set screw 1114 may secure the shaft 710 to the rotor base 712. Mechanical or electrical power may be taken from the rotating shaft 710 coupled to the rotor 110. In this aspect, a secondary power take-off 1116 may be present on the upper portion 1120 of the rotor 110. The secondary power take-off 1116 may be geared using one or more gears 1118 in order to take power directly off of the rotor 110.

[0079] In another aspect shown in FIG. 11, electrical generation capability may be within the rotary expansion device 200 wherein coils (not shown) may be within piping 1128. One or more magnets 1126 may be coupled onto the rotor 110 of the rotary expansion device 1130. This configuration may reduce or eliminate seals and/or bearings versus the configuration wherein the shaft 710 is outside of the rotary expansion device 200. This configuration may increase overall efficiency and may improve compactness of the rotary expansion device 200. [0080] According to another aspect shown in FIGS. 12A and 12B, a rotary expansion system 1200 may comprise a series of the expansion rotary devices 200. The aspect shown in FIGS. 12A (front view) and 12B (perspective side view) show three expansion rotary devices 200 but more or less of the devices 200 may be used. As shown more clearly in FIG. 12B, each of the expansion rotary devices 200 is placed in parallel from the high-pressure gas supply 1002. Each of the expansion rotary devices 200 may be controlled using the control valve 1004. Each of the expansion rotary devices 200 may be attached to a primary power take-off 1202 (e.g. a generator) via a shaft 702. The gas and/or condensation discharge from each of the rotary devices 200 may be combined and/or passed through a discharge isolation valve 1204 into a large separation vessel 1206. Within the large separation vessel 1206, the condensed liquid may flow into a fluid boot 1208 at the bottom of the large separation vessel 1206 and/or may be removed from the boot 1208 using a fluid dump valve 1210. Any gas may be passed through a low pressure gas outlet 1212 located near a top of the large separation vessel 1206.

[0081] As shown in further detail in a front view of FIG. 13 A and a cross-section side view in FIG. 13B, the ports 112 may be rectangular in shape and tapered towards an outlet as previously described. Other aspects may be the ports 112 being circles, ovals, and/or any combination of shape. An expansion ratio may be determined by a sizing and/or tapering of each port 112. When the ports 112 exceed a certain size, a horizontal stress may exceed a strength of a material of which the rotor 110 is made. As a diameter of the rotor 110 increases, the centrifugal force to the expansion ports 112 may also increase. A length of expansion ports 112 along the rotor 110 may affect gas migration to the ports 112 furthest from the inlet pipe 202 causing reduced effectiveness of lengthening the ports 112. Therefore, the number of expansion ports 112 may change with a size of the rotor 110 thus increasing the number of expansion port sections along the outside of the rotor 110 may prove more effective.

[0082] Although the ports 112 in previous aspects demonstrate that the ports 112 may be staggered, offset, or unaligned with each other, other aspects may have the ports 112 stacked as shown in the example of FIGS. 14A and 14C where three layers 2302 of ports 112 have been stacked with each layer 2302 aligned with each other. Other aspects may have the layers 2302 of ports 112 offset at specified angles around the circumference of the rotor 110 as is illustrated in FIG 14B and 14D. For example, a system with 4-point nozzle 112 may have a first row with nozzle angles at 0-degrees, 90-degrees, 180-degrees, and 270-degrees. The next row may be offset to nozzle angles of 45-degrees, 135-degrees, 225-degrees, and 315-degrees and in some aspects, the third row may return to the same angles as the first row or be offset to different angles. This type of formation may add strength to the rotor 110 and/or provide more stable airflow to the stator 220. FIG 14E shows three dimensional illustrations of the internal gas flows of the rotor in side by side comparison of a stacked port design and staggered port design from three different angles. Similar to FIG. 7, the body of the rotor 110 has been removed from FIGs. 14A to 14E to enable viewing of the internal structure of the ports 112.

[0083] In some aspects, such as shown in FIG. 15, the expansion port 112 may receive a tapered insert 1602 that may be pressed or secured into the expansion port(s) 112. The inserts 1602 may be configured to customize the ports 112 from a standardized design of the rotor 110. The inserts 1602 may also be replaceable as the ports 112 may be an area of high wear.

[0084] Similar to the rotor 110, the stator 220 may have different shapes and/or numbers for the stator fins 310. For example, FIG. 16 shows a top cross-sectional view of the stator 220 having twelve stator fins 310. In another example, FIG. 17 shows a top cross-sectional view of the stator 220 having twelve stator fins 310 of different composition. Other aspects may have more or less stator fins 310. For the same circumference of stator 220, having fewer stator fins 310 results in the stator fins 310 being longer and having more stator fins 310 results in the stator fins 310 being shorter.

[0085] According to some aspects, the stator fins 310 may be replaceable as the stator fins 310 may be a high wear component. In some aspects, the stator fins 310 may be placed on an interior of a sleeve insert 1902 as shown particularly in FIGS. 18A and 18B. The sleeve insert 1902 may be slid into the stator 220 and secured in place using one or more fasteners, such as bolts or clips capable of handling the related stresses.

[0086] Although the stator 220 has been presented above as generally cylindrical as shown in FIG. 18 A, other aspects may have the stator 220 taper inward from a bottom of the stator 220 to a top of the stator 220, such as can be seen in FIGS. 18B, 19B, and 21A to 21C, described in further detail below.

[0087] Turning to FIGS. 20A and 20B, the stator 220 may be coupled to a support cage 2100 that may be configured to allow the stator 220 to slide vertically with respect to the rotor 110. The support cage 2100 may comprise one or more guide rods 2102 located around a periphery of an upper support ring 2106 and a lower support ring 2108. A pair of rams 2104 may raise and/or lower the upper support ring 2106 and the lower support ring 2108. A casing mount 2110 may enclose the guide rods 2102 and/or the support rings 2106, 2108.

[0088] As seen more clearly in FIGS. 21A to 21C, the stator 220 may be a conical -tapered stator 220 being narrower at a top 2202 of the stator 220 and wider at a bottom 2204 of the stator 220. When the rotor 110 is at full speed, such as shown in FIG. 2 IB, a clearance between the rotor 110 and the stator 220 may be tighter. As the rotor 110 decreases in rotational velocity or during startup, the clearance between the rotor 110 and the stator 220 may be increased as shown in FIG. 21C in order to reduce damage or wear to the stator 220. The clearance may be adjusted by using the rams 2104 to move the stator 220 upwards so that the rotor 110 moves towards the wider end 2204 of the tapered stator 220 or vice versa.

[0089] During startup the adjustable clearance may be advantageous to bring the rotor 110 up to speed gradually. The gradual increase in speed may limit any high velocity flow out of the expansion ports 112 as this type of flow could damage or increase wear to the stator 220. Once a design point flow and/or rpm may be reached, the clearance may be reduced. At the operating rpm, the shaft power may be specified by the design. Efficiency may be determined by an expansion calculation employed universally amongst expansion technology.

[0090] In another aspect (not shown), the taper of the stator 220 may be inverted so that the wider end is at the top of the stator 220 and the narrower end 2202 is at the bottom of the stator 220. In this aspect, the rams 2104 may lower the stator 220 as the rotational velocity of the rotor 110 decreases thereby moving the rotor 110 to the wider top of the stator 220.

[0091] Although the aspects described above demonstrate different numbers of ports 112 on the rotor 110, other aspects may have fewer or more ports 112 on the rotor 110. For example, shown in FIG. 22 A to 22C, two ports 112 are present on the rotor 110. In another aspect shown in FIG. 23 A, three ports 112 are present on each layer 2302 of the rotor 110. Multiple configurations may be possible as the sizing scales up and down, the number of ports 112 may be changed to meet required and/or optimal conditions. For example, FIG. 23 A to 23C demonstrate nine ports 112 (e.g. three ports 112 per level or layer 2302 of ports 112). Although depicted as formed of the same material, some aspects may comprise a number of levels or layers 2302 of ports 112 bolted or fastened together.

[0092] In another aspect shown in FIGS. 24 A and 24B, the rotor 110 may incorporate one or more inlet blades 2402 to aid in a compressional flow to the expansion ports 112. In this example, the inlet blades 2402 may increase the inflow of the high-pressure gas to the expansion ports 112.

[0093] Turning to FIG. 25, the centrifugal force of compression is depicted. The rotor 110 may have the rotational force in the direction denoted by the arrows 2502. The gas density may be depicted by circles for a visualization representation of the gas pressure within the rotor 110. The high-pressure gas flows into the converging section 704 of the nozzle 2504 and as shown by the arrows directed outward by a centrifugal force and/or the inner curved wall of the nozzle 2504. The centrifugal force and/or the inner curved wall may cause a bubble of increased higher pressure to form at the inlet to the throat 2506. The bubble of increased pressure may lead to a higher mass flow through the nozzle 2504 than would be possible from merely flowing the high pressure gas through the throat 2506 of a same size without the centrifugal compression generated by the expansion rotary device 200. This compression work may be performed at an extremely high efficiency as the compression work may happen nearly instantaneously into the throat 2506 before expansion in the diverging section 708 of the nozzle 2504. The low pressure, high velocity gas may then exit the expansion port 2508 to be received by the stator 220.

[0094] To determine the centrifugal compression work generated by the device 200 and the corresponding pressure increase, one or more of the following may be considered: a density of the gas, a diameter of the rotor, a size of the converging section 704 of the expansion port 112 and/or an angle of the inner wall of the converging section of the expansion port 112. In one aspect, the device 200 may increase a pressure ratio (e.g. rotor pressure to stator pressure) from rotor 110 to stator 220 from 3: 1 to 4: 1. The higher-pressure gas feeding the inlet to the rotor 110 of the expansion device 200 may remain at constant-pressure, but a flow meter employed on this gas feed may show the mass flow increasing into the expansion device 200 as the rotor 110 increases in velocity up to the desired rpm. Based on the increased mass flow at the rotational velocity and/or rpm of the rotor 110, the increased pressure bubble created in the converging section 704 entering the throat 508 may correlate this higher mass flow to a higher-pressure (Mach 1) flow rate through this size of orifice of the throat 508 restriction. [0095] Although the aspects herein describe the rotor 110 supplied with the high-pressure gas, the use of “high-pressure” is merely used for convenience to denote that the gas may be a higher pressure than a gas within the stator 220. The rotor 110 may have a rotor pressure and the stator 220 may have a stator pressure wherein the rotor pressure is higher than the stator pressure for the expansion device 200 to operate. [0096] The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous changes and modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all such suitable changes or modifications in structure or operation which may be resorted to are intended to fall within the scope of the claimed invention.

Claims

25 What is claimed is:

1. A rotary expansion device comprising: a rotor receiving a gas centrally within the rotor; at least one expansion port in the rotor expelling the gas at an exit velocity from an outer surface of the rotor; a stator receiving an expelled gas; and the exit velocity of the expelled gas imparts a rotational velocity to the rotor.

2. The rotary expansion device according to claim 1 , wherein the rotor rotates at the rotational velocity regulated by a rotor pressure of the gas relative to a stator pressure.

3. The rotary expansion device according to any one of claims 1 to 2, wherein the exit velocity matches the rotational velocity of the rotor.

4. The rotary expansion device according to any one of claims 1 to 3, wherein the rotor comprises at least one short end and at least one long edge alternating around a perimeter of the rotor and forming the at least one expansion port.

5. The rotary expansion device according to any one of claims 1 to 4, wherein each of the at least one expansion port comprises a converging section and a diverging section.

6. The rotary expansion device according to claim 5, wherein the converging section and the diverging section are separated by a throat near which the gas reaches a maximum flow rate.

7. The rotary expansion device according to claim 6, wherein the maximum flow rate reaches a supersonic velocity determined by at least one specific property of the gas.

8. The rotary expansion device according to claim 5, wherein a centrifugal compression due to the rotational velocity of the rotor provides additional pressure between the converging section and the diverging section.

9. The rotary expansion device according to claim 5, wherein the diverging section determines the exit velocity from the at least one expansion port.

10. The rotary expansion device according to any one of claims 1 to 9, further comprising a pressurized pipe providing the gas to the rotor.

11. The rotary expansion device according to claim 10, wherein the pressurized pipe is rotatably coupled to the rotor.

12. The rotary expansion device according to any one of claims 1 to 11, wherein the stator comprises at least one stator fin protruding towards the rotor; and receiving the expelled gas.

13. The rotary expansion device according to claim 12, wherein the at least one stator fin inhibits the expelled gas from forming a rotational flow.

14. The rotary expansion device according to claim 13, wherein each of the at least one stator fin comprise a long edge and a short edge.

15. The rotary expansion device according to any one of claims 1 to 14, wherein the rotor comprises at least two layers comprising a plurality of the expansion ports.

16. The rotary expansion device according to claim 15, wherein the plurality of the expansion ports on each of the layers are staggered vertically.

17. The rotary expansion device according to any one of claims 1 to 16, further comprising a generator producing electrical energy from the rotor.

18. The rotary expansion device according to any one of claims 1 to 17, wherein the gas is condensed to produce condensation.

19. The rotary expansion system comprising a plurality of the expansion rotary devices according to any one of claims 1 to 17.

20. A method of producing a rotational motion of a rotor, the method comprising: receiving a gas along a central axis within the rotor; expelling the gas at an exit velocity via at least one expansion port in the rotor; receiving the expelled gas by a stator; and rotating the rotor at a rotational velocity.