Generating power with turboexpander generator based on specified output conditions

Abstract

The first turboexpander generator defines a portion of the first conduit flow channel. The first turbo-expander generator is configured to reduce a temperature or pressure of a process stream flowing through the first turbo-expander generator by generating electrical power from the process stream flowing through the first turbo-expander generator. The second turboexpander generator defines a portion of a second conduit flow channel. The second turbo-expander generator is configured to reduce a temperature or pressure of a process stream flowing through the second turbo-expander generator by generating electrical power from the process stream flowing through the second turbo-expander generator. The first conduit flow channel and the second conduit flow channel are arranged to carry a fluid flow in parallel with each other. The first turboexpander generator and the second turboexpander generator are substantially consistent in critical size and performance.

Description

Priority claim

[0001] This application claims priority to U.S. patent application No. 17 / 662,023, filed on May 4, 2022, which is a continuation-in-part of and claims priority to U.S. patent application No. 17 / 658,606, filed on April 8, 2022, and the contents of these U.S. patent applications are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to power generation. Background Art

[0003] Natural gas is one of the main sources of energy for many of our daily needs and activities. Natural gas is an attractive fossil fuel due to its abundance. Hydrogen is a rapidly expanding global energy storage market. Hydrogen is used in many manufacturing processes from oil refining to food processing. Hydrogen is also used as a fuel source for gas turbines and is used in a wide range of fuel cells to generate electricity in the industrial and consumer transportation sectors.

[0004] Moving these gases effectively and efficiently from production areas to consumption areas requires a large and complex transportation system. Natural gas transported through pipelines travels at high pressure within the pipelines. Summary of the invention

[0005] The present disclosure relates to generating electrical power using a turboexpander generator based on specified output conditions.

[0006] An example embodiment of the subject matter described in the present disclosure is a system having the following features. A first turboexpander generator defines a portion of a first conduit flow channel. The first turboexpander generator is configured to reduce the temperature or pressure of a process stream flowing through the first turboexpander generator by generating electricity from the process stream flowing through the first turboexpander generator. A second turboexpander generator defines a portion of a second conduit flow channel. The second turboexpander generator is configured to reduce the temperature or pressure of a process stream flowing through the second turboexpander generator by generating electricity from the process stream flowing through the second turboexpander generator. The first conduit flow channel and the second conduit flow channel are arranged to carry fluid flows in parallel with each other. The first turboexpander generator and the second turboexpander generator are substantially identical in key dimensions and performance.

[0007] Aspects of the example system that may be included in the example system alone or in combination with other aspects include the following: A controller is configured to regulate the first turbine expander generator and the second turbine expander generator.

[0008] Aspects of the example system that may be included in the example system alone or in combination with other aspects include the following. The first turboexpander generator or the second turboexpander generator includes a rotor. A stator surrounds the rotor. A magnetic bearing carries the rotor within the stator. A portion of the magnetic bearing is supported by the stator. A housing encloses the rotor and the stator. The housing is hermetically sealed between an inlet and an outlet of each turboexpander generator.

[0009] Aspects of the example system that may be included in the example system alone or in combination with other aspects include the following. The inlet and the outlet of each turboexpander are centered on the same longitudinal axis of each turboexpander generator.

[0010] Aspects of the example system that may be included in the example system alone or in combination with other aspects include the following: The stator includes variable stator vanes configured to throttle fluid flow through the first turboexpander generator or the second turboexpander generator.

[0011] Aspects of the example system that may be included in the example system alone or in combination with other aspects include the following: A first flow control valve is upstream of the first turboexpander generator. The first flow control valve is configured to regulate flow through the first turboexpander generator.

[0012] Aspects of the example system that may be included in the example system alone or in combination with other aspects include the following: A second flow control valve is upstream of the second turboexpander generator. The second flow control valve is configured to regulate flow through the second turboexpander generator.

[0013] Aspects of the example system that may be included in the example system alone or in combination with other aspects include the following: A Joule-Thomson valve defines a portion of a third conduit flow channel arranged to carry fluid flow in parallel with the first and second conduit flow channels.

[0014] An example of the subject matter described in the present disclosure is a method having the following features. A first turboexpander generator receives a first fluid flow through a portion of a first conduit flow channel. A second turboexpander generator receives a second fluid flow through a portion of a second conduit flow channel. The first conduit flow channel and the second conduit flow channel are arranged to carry the fluid flows in parallel. The first turboexpander generator and the second turboexpander generator are substantially identical in performance and critical dimensions.

[0015] Aspects of the example method that may be included in the example method alone or in combination with other aspects include the following. The first fluid stream and the second fluid stream include hydrocarbon gas.

[0016] Aspects of the example method that may be included in the example method alone or in combination with other aspects include the following. The first fluid stream and the second fluid stream include hydrogen.

[0017] Aspects of the example method that may be included in the example method alone or in combination with other aspects include the following. The first fluid flow and the second fluid flow include air.

[0018] Aspects of the example method that may be included in the example method alone or in combination with other aspects include the following. The first fluid stream flows through an annulus defined by a motorized rotor and a motorized stator of the first turboexpander generator.

[0019] Aspects of the example method that may be included in the example method alone or in combination with other aspects include the following. Electricity is generated by the first turboexpander generator.

[0020] Aspects of the example method that may be included in the example method alone or in combination with other aspects include the following. Electricity is generated by the second turboexpander generator.

[0021] Aspects of the example method that may be included in the example method alone or in combination with other aspects include the following: Ceasing to generate electrical power by the first turboexpander generator or the second turboexpander generator in response to a change in a specified downstream condition.

[0022] Aspects of the example method that may be included in the example method alone or in combination with other aspects include the following. Generating electricity by the first turboexpander generator includes adjusting flow through a flow control valve based on specified downstream conditions.

[0023] Aspects of the example method that may be included in the example method alone or in combination with other aspects include the following: Directing power generated by the first turboexpander generator or the second turboexpander generator toward a user of power separate from users of the first and second fluid flows.

[0024] An example of the subject matter described in the present disclosure is a system having the following features. A first turboexpander generator defines a portion of a first conduit flow channel. The first turboexpander generator is configured to reduce the temperature or pressure of a process flow flowing through the first turboexpander generator by generating electricity from the process flow flowing through the first turboexpander generator. A second turboexpander generator defines a portion of a second conduit flow channel. The second turboexpander generator is configured to reduce the temperature or pressure of a process flow flowing through the second turboexpander generator by generating electricity from the process flow flowing through the second turboexpander generator. The first conduit flow channel and the second conduit flow channel are arranged to carry fluid flow in parallel with each other. The first turboexpander generator and the second turboexpander generator are substantially identical in key dimensions and performance. A Joule-Thomson valve defines a portion of a third conduit flow channel. The first conduit flow channel, the second conduit flow channel, and the third conduit flow channel are arranged to carry fluid flow in parallel with each other. A controller is configured to regulate the first turboexpander generator and the second turboexpander generator.

[0025] Aspects of the example system that may be included in the example system alone or in combination with other aspects include the following. The first turboexpander generator or the second turboexpander generator includes the following features, respectively. A stator surrounds a rotor. A magnetic bearing carries the rotor within the stator. A portion of the magnetic bearing is supported by the stator. A housing encloses the rotor and the stator, the housing being hermetically sealed between an inlet and an outlet of each turboexpander generator.

[0026] Aspects of the example system that may be included in the example system alone or in combination with other aspects include the following: The stator includes variable stator vanes configured to throttle fluid flow through the first turboexpander generator or the second turboexpander generator.

[0027] Aspects of the example system that may be included in the example system, alone or in combination with other aspects, include the following. A first flow control valve is upstream of the first turboexpander generator. The first flow control valve is configured to regulate flow through the first turboexpander generator. A second flow control valve is upstream of the second turboexpander generator. The second flow control valve is configured to regulate flow through the second turboexpander generator.

[0028] Aspects of the example system that may be included in the example system alone or in combination with other aspects include the following. A third turboexpander generator defines a portion of a fourth conduit flow path.

[0029] Aspects of the example system that may be included in the example system alone or in combination with other aspects include the following: The fourth conduit flow channel is arranged to carry fluid flow in parallel with the first conduit flow channel, the second conduit flow channel, and the third conduit flow channel.

[0030] Aspects of the example system that may be included in the example system alone or in combination with other aspects include the following: The fourth conduit flow channel is arranged in series with the first conduit flow channel.

[0031] Aspects of the example system that may be included in the example system alone or in combination with other aspects include the following. The controller is further configured to: receive a data stream indicating process conditions downstream of the first turboexpander generator and the second turboexpander generator; and adjust flow through a flow control valve based on one or more specified downstream conditions.

[0032] Aspects of the example system that may be included in the example system alone or in combination with other aspects include the following. The controller is further configured to: regulate the power generated by the first turboexpander generator and the second turboexpander generator; and direct the power into a power grid. The power is in phase with the power grid.

[0033] The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic cross-sectional view of an electric power generation system having a turboexpander generator coupled to a grid.

[0035] Figure 2 is a perspective view of an example system arrangement including turboexpander generators piped in parallel with each other.

[0036] Figure 3 is a schematic block diagram of an example system arrangement including two turboexpander generators piped in parallel to each other.

[0037] Figure 4 is a block diagram of an example controller that may be used with aspects of the present disclosure.

[0038] Figure 5 is a perspective view of an example system arrangement including two turboexpander generators piped in series with each other.

[0039] Figure 6 is a schematic block diagram of an example system arrangement including two turboexpander generators piped in series with each other.

[0040] Figure 7 is a flow diagram of an example method that may be used with aspects of the present disclosure.

[0041] Like reference numbers in the various drawings represent like elements. Specific implementation plan

[0042] Natural gas, hydrogen and other process gases are pressurized for efficient transportation in pipelines that are sometimes several miles long. For example, pipelines transport gas from production sites (e.g., wells) to processing facilities, and from processing facilities to local distribution networks, such as regional, city or administrative district networks or on-site industrial plant networks. In order to safely transport the gas through the local distribution network and for use, the process gas is decompressed to a lower level (usually using a pressure regulator, such as a Joule-Thomson valve). The pressure is stepped down at a pressure letdown (PLD) station for delivery to industrial, commercial and residential end users. PLD stations use regulating valves to achieve the required pressure drop, but a lot of energy is also wasted in the process. Additional regulating valves can be used for pressure control at other locations, such as in pipelines between production facilities and processing facilities, in sub-processes of process facilities, and in processes and pipelines of end users.

[0043] A turboexpander generator can be installed to recycle the energy wasted due to pressure reduction and generate electricity. Electricity can be directed to the power grid or other places of the PLD station. In the embodiment where electricity is directed to the power grid, the power grid can include a local power grid, a local isolated power grid or a municipal power grid for the facility. In some embodiments, the electricity generated by the turboexpander generator is sold to a municipal power supplier. Similarly, a turboexpander generator can be installed at a gas storage facility upstream of one or more storage tanks to recycle the high-pressure gas distributed from the tanker truck to the storage tank through the turboexpander generator. The turboexpander generator is relevant in other applications, such as in the following hydrogen liquefaction process, in which the gaseous hydrogen that has been cooled and pressurized will expand into a liquid state. Expansion can be performed by a turboexpander generator to recycle the energy wasted by expansion and generate electricity. As described above, electricity can be directed to the power grid or other places, such as being used to power compressors or other components of the liquefaction process. In each case, by recovering the energy lost in the pressure reduction application of natural gas and hydrogen, the turboexpander can generate electricity, while also reducing CO2 emissions, improving the efficiency of the entire plant, offsetting electricity costs and generating additional income.

[0044] Figure 11 is a schematic cross-sectional view of a power generation system 100 having a turboexpander generator 102 coupled to a power grid 140. The power generation system 100 may be added at a PLD station to capture energy from gas expansion from a PLD process, or added in any other application described above. The power generation system 100 includes a turboexpander generator 102 in parallel with a pressure control (valve) 130. The turboexpander generator 102 is arranged axially so that the turboexpander generator 102 can be mounted in line with the pipe. In other words, the inlet 150 and the outlet 152 of the turboexpander generator 102 are centered on the same longitudinal axis (centerline 180) of the turboexpander generator 102. The turboexpander generator 102 is used as a generator that generates electrical energy by generating rotational kinetic energy from the expansion of a process gas 120 through a turbine impeller 104. For example, the rotation of the turbine impeller 104 can be used to rotate the rotor 108 within the stator 110, thereby generating electricity.

[0045] The turboexpander generator 102 comprises a high performance, high speed permanent magnet generator with an integrated radial inflow expansion turbine wheel 104 and low loss active magnetic bearings (AMBs) 116a and 116b. The rotor assembly comprises a permanent magnet section with the turbine wheel 104 mounted directly to the rotor hub. The rotor 108 is suspended by a magnetic bearing system, thereby creating a frictionless (or near frictionless) interface between the dynamic and static components. The AMBs 116a, 116b facilitate the lossless (or near lossless) rotation of the rotor 108.

[0046] The turboexpander generator 102 is designed to flow the process gas 120 through the system 100, thereby cooling the generator and eliminating the need for auxiliary cooling equipment. In some embodiments, the turboexpander controller 118 for the turboexpander generator 102 combines the power converter 186 and the magnetic bearing controller (MBC) 212 into one cabinet. The power converter 186 allows the power generated from the turboexpander generator 102 to be consistently and cleanly delivered to the power grid 140. The power converter 186 adjusts the frequency and amplitude of the generated current to match the local power grid. In some embodiments, the power converter 186 is used as a power regenerator, which converts the electricity generated by the turboexpander generator 102 into DC electricity, and then generates the phase, frequency and voltage of the AC waveform to synchronize and distribute to the power grid 140. After expansion, the process gas 120 leaves the turboexpander generator 102 along the same axial path for downstream processes.

[0047] The turboexpander generator 102 includes a flow-through configuration. The flow-through configuration allows the process gas 120 to flow from the inlet side of the turboexpander generator 102 to the outlet side of the turboexpander generator 102. The process gas 120 flows into the radial gas inlet 154 to the turbine impeller 104 and flows out of the turbine impeller 104 from the axial gas outlet 156. In some embodiments, the stator includes variable stator blades 182 located at the outlet 154. The variable stator blades 182 are configured to throttle the fluid flow through the turboexpander generator 102, and the variable stator blades 182 can be used as a substitute or supplement to the convection control (system) 126. Then, the process gas 120 flows through the generator and flows out of the inlet 154, where the process gas 120 rejoins the gas pipeline 170. In general, the process gas 120 is directed through the flow control system 126 to flow into the turboexpander generator 102. The flow control system 126 includes flow control valves or mass control valves and emergency shut-off valves. The flow control system 126 may be controlled by the turboexpander controller 118 or other electrical, mechanical, or electromagnetic signals. For example, a fault condition may signal the flow control system 126 to shut down or partially shut down, thereby removing or limiting the gas supply to the turboexpander generator 102. Limiting or eliminating gas flow to the turboexpander while maintaining a constant rotational speed of the turbine wheel reduces the electrical power output from the turboexpander generator 102. Figure 1 In the example shown, the flow control system 126 may be opened and / or closed using a signal channel 164 from the turboexpander controller 118 In some embodiments, the turboexpander housing 112 is hermetically sealed between the inlet 150 and the outlet 152 .

[0048] The process gas 120 expands by flowing through the turbine impeller 104, thereby causing the pressure of the process gas 120 to drop. The process gas 120 leaves the turboexpander generator 102 at a reduced pressure and / or temperature. The expansion of the process gas 120 across the turbine impeller 104 causes the turbine impeller 104 to rotate, thereby causing the rotor 108 to rotate. The rotation of the rotor 108 in the stator 110 generates electricity. The turboexpander generator 102 achieves the specified pressure drop and captures the energy from the pressure drop to generate electricity. A pressure control valve 130 (e.g., a conventional pressure regulator or a Joule-Thomson valve) can be installed in parallel (or in series) with the turboexpander generator 102. The pressure control valve 130 can be used to control the pressure of the process gas 120 flowing through the turboexpander generator 102. Any excess high-pressure process gas 120 that is not directed into the turboexpander generator 102 can be directed through the pressure control valve 130.

[0049] In some embodiments, the heater 122 can heat the process gas 120 before the process gas 120 flows into the turboexpander generator 102. For example, if the expansion of the process gas 120 through the turbine impeller 104 reduces the temperature of the process gas 120 to a temperature point at which moisture in the process gas 120 freezes at the turbine impeller 104 or another downstream location, the process gas 120 can be heated by the heater 122 before entering the turboexpander generator 102. After heating, the process gas 120 can then be directed into the turboexpander generator 102. Heating the process gas 120 can prevent moisture from freezing as the process gas 120 expands and the temperature of the process gas decreases. In some embodiments, the process gas is heated by the heater after leaving the turboexpander 102.

[0050] The turboexpander generator 102 includes a turbine wheel 104. The turbine wheel 104 is shown as a radial inflow turbine wheel, but other configurations are also within the scope of the present disclosure, such as an axial inflow turbine wheel. In this example, the process gas 120 is received from the inlet duct 150 of the housing 112 and enters the radially oriented inlet 154 of the turbine wheel 104. In some embodiments, the process gas 120 flows through the inlet duct 150 and is diverted by the flow diverter to the radial inlet 154, which guides the fluid into the radial flow inlet of the turbine wheel 104. After expansion, the process gas 120 leaves the turbine wheel 104 from the axially oriented outlet 156 to the outlet duct 152 of the housing 112.

[0051] In some embodiments, the turbine impeller 104 is directly fixed to the rotor 108, or fixed to the intermediate common shaft, such as by fasteners, rigid drive shafts, welding or other means. For example, the turbine impeller 104 can be received at the end of the rotor 108 and is retained to the rotor 108 using an axle. The axle is screwed into the rotor 108 at one end, and the turbine impeller 104 is captured between the end of the rotor 108 and a nut at the other end, and the nut is received on the axle by a thread. In some embodiments, the turbine impeller 104 and the rotor 108 are coupled without a gearbox and rotate at the same speed. In some embodiments, the turbine impeller 104 is indirectly coupled to the rotor 108, which is achieved, for example, by a gear train, a clutch mechanism or other means.

[0052] The turbine wheel 104 includes a plurality of turbine wheel blades 106 that extend outwardly from a hub and interact with the expanding process gas 120 to cause the turbine wheel 104 to rotate. Figure 1An unshrouded turbine wheel 104 is shown, wherein each turbine blade 106 has an exposed, generally radially oriented blade tip extending between a radial inlet 154 and an axial outlet 156. As discussed in more detail below, the blade tips are substantially sealed to the shroud 114 within the interior of the housing 112. In some cases, the turbine wheel 104 is a shrouded turbine wheel.

[0053] In the configuration of the turbine wheel 104 without a shroud, the housing 112 includes an inwardly directed shroud 114 that is immediately adjacent to the turbine blades 106 and is not in contact with the turbine blades 106 for most of the time during operation. As the process gas 120 flows through the turbine wheel 104, the close proximity of the turbine blades 106 to the shroud 114 substantially seals the passage of the process gas 120 therebetween. Although a certain amount of process gas 120 may leak or pass between the turbine blades 106 and the shroud 114, the leakage is not noticeable in the operation of the turbine wheel 104. In some cases, using conventional tolerances between the turbine blades 106 and the shroud 114, the leakage may be comparable to other similar turbine / shroud surface interfaces without a shroud. The amount of leakage that is considered an acceptable leakage may be predetermined. The operating parameters of the turbine generator may be optimized to reduce leakage. In some embodiments, the housing 112 is hermetically sealed to prevent the process gas 120 from escaping from the radial inlet 154 of the turbine wheel 104 .

[0054] The shroud 114 may be located at a specified distance away from the turbine wheel blades 106 and maintained at the distance away from the turbine wheel blades 106 during operation of the turboexpander generator 102 by using a magnetic positioning device including active magnetic bearings and position sensors.

[0055] The bearings 116a and 116b are arranged to rotatably support and carry the rotor 108 and the turbine wheel 104 relative to the stator 110 and the shroud 114. In some embodiments, the turbine wheel 104 is supported by the bearings 116a and 116b in a cantilever (overhanging) manner. In some embodiments, the turbine wheel 104 is supported in a non-cantilever manner, and the bearings 116a and 116b can be located on the outlet side of the turbine wheel 104, for example, in an inter-bearing arrangement. In some embodiments, one or more of the bearings 116a or 116b include ball bearings, needle bearings, magnetic bearings, foil bearings, journal bearings, or other bearings.

[0056] The bearings 116a and 116b may be a combination of radial bearings and thrust bearings, supporting the rotor 108 in both radial and axial directions. Other configurations may be used. The bearings 116a and 116b need not be the same type of bearings.

[0057] In an embodiment where the bearings 116a and 116b are magnetic bearings, a magnetic bearing controller (MBC) 212 is used to control the magnetic bearings 116a and 116b. Position sensors 117a, 117b can be used to detect the position or change in position of the turbine impeller 104 and / or rotor 108 relative to the housing 112 or other reference points (e.g., predetermined values). The position sensors 117a, 117b can detect axial and / or radial displacements. The magnetic bearings 116a and / or 116b can respond to information from the position sensors 117a, 117b and adjust the detected displacements if necessary. The MBC 212 can receive information from (one or more) position sensors 117a, 117b and process the information to provide control signals to the magnetic bearings 116a, 116b. The MBC 212 can communicate with various components of the turboexpander generator 102 via the communication channel 162.

[0058] The use of magnetic bearings 116a, 116b and position sensors 117a, 117b to maintain and / or adjust the position of the turbine wheel blades 106 allows the turbine wheel blades 106 to remain in close proximity to the shroud 114, thereby allowing the turboexpander generator 102 to operate without bearing seals (e.g., without dynamic seals). The use of active magnetic bearings 116a, 116b in the turboexpander generator 102 eliminates physical contact between rotating and stationary components and reduces or eliminates the need for lubrication, lubrication systems, and seals.

[0059] In some embodiments, the turboexpander generator 102 includes one or more backup bearings. For example, during startup and shutdown or in the event of a power outage that affects the operation of the magnetic bearings 116a and 116b, the bearings can be used to rotatably support the turbine wheel 104 during that period of time. The backup bearings can include ball bearings, needle bearings, journal bearings, or similar bearings.

[0060] As previously described, the turboexpander generator 102 is configured to generate electricity in response to the rotation of the rotor 108. In some cases, the rotor 108 may include one or more permanent magnets. The stator 110 includes a plurality of conductive coils. Electricity is generated by the rotation of the magnets within the coils of the stator 110. The rotor 108 and the stator 110 may be configured as a synchronous, permanent magnet, multi-phase alternating current (AC) generator. For example, the electrical output 160 may be a three-phase output. In some cases, the stator 110 may include a plurality of coils (e.g., three or six coils for a three-phase AC output). When the rotor 108 rotates, a voltage is induced in the stator 110. At any time, the magnitude of the voltage induced in the stator coil is proportional to the rate at which the magnetic field enclosed by the coil changes over time (i.e., the rate at which the magnetic field passes through both sides of the coil). In the case where the rotor 108 is coupled to rotate at the same speed as the turbine impeller 104, the turboexpander generator 102 is configured to generate electricity at that speed. Such a turboexpander generator 102 is a so-called "high-speed" turbine generator. For example, the turboexpander generator 102 may generate up to 135 kW at a continuous speed of 30,000 rpm. In some embodiments, the turboexpander generates approximately 315 kW at a higher rotational speed (eg, approximately 23,000 rpm).

[0061] In some embodiments, the design of the turbine wheel 104 is based on specified parameters of the output gas from the turboexpander generator 102. For example, the design of the rotor and stator may be based on a specified temperature of the process gas 120 exiting the turboexpander generator 102. In some embodiments, the turboexpander generator is constructed as a single size with interchangeable turbine wheels 400 that may be replaced for a specified output and process.

[0062] The turboexpander generator 102 is coupled to a turboexpander controller 118. The turboexpander controller 118 may include various components, such as a power converter 186 and / or a magnetic bearing controller (MBC) 212 (as discussed above). The power converter 186 may be, for example, a variable speed drive (VSD) or a variable frequency drive.

[0063] The electrical output 160 of the turboexpander generator 102 is connected to a power converter 186, which can be programmed for a specific power requirement. In some embodiments, the power converter 186 may include an insulated-gate bipolar transistor (IGBT) rectifier 188 to convert the variable-frequency high-voltage output from the turboexpander generator 102 into a direct current (DC). In some embodiments, the rectifier 188 is a three-phase rectifier for a three-phase AC input current. The inverter 210 then converts the DC from the rectifier 188 into AC to supply the grid 140. In certain embodiments, the inverter 210 converts the DC into 380V AC to 480V AC at 50 Hz to 60 Hz for delivery to the grid 140. The specific output of the power converter 186 depends on the grid 140 and the application. Other conversion values ​​are also within the scope of the present disclosure. Power converter 186 matches the output of power converter 186 to grid 140 by sampling the voltage and frequency of the grid and then changing the output voltage, phase, and frequency of inverter 210 to match or synchronize to the sampled voltage, phase, and frequency of the grid.

[0064] In some embodiments, the power converter 186 is a bidirectional power converter. In such an embodiment, the rectifier 188 can receive an AC current from the power grid 140 and convert the AC current into a DC current. Then, the inverter 210 can convert the DC from the rectifier 188 into AC to supply the generator. In such an embodiment, the power can be delivered from the power grid 140 to the generator to drive the rotation of the rotor 108, and then drive the turbine impeller 104 to induce the flow of the process gas. In short, in the embodiment where the power converter 186 is a bidirectional power converter, the flow of power can be reversed and used by the generator to induce the flow of the process gas (contrary to the process gas contributing to the expansion work to generate electricity).

[0065] The turboexpander generator 102 is also connected to the MBC 212 in the turboexpander controller 118. The MBC 212 continuously monitors position, current, temperature, and other parameters to control the turboexpander generator 102 and the active magnetic bearings 116a and 116b. For example, the MBC 212 is coupled to the position sensors 117a, 117b to monitor the radial and axial positions of the turbine impeller 104 and the rotor 108. The MBC 212 can control the magnetic bearings 116a, 116b to selectively change the stiffness and damping characteristics of the magnetic bearings 116a, 116b according to the rotational speed. The MBC 212 can also control synchronization cancellation, including automatic balancing control, adaptive vibration control, adaptive vibration suppression, and unbalanced force suppression control.

[0066] Figure 2 200 is a perspective view of an example system 200 including two turboexpander generators 102 connected in parallel pipes to each other. That is, the fluid flow can flow through the first turboexpander generator 102a or the second turboexpander generator 102b, but not through both. In some embodiments, this arrangement is used in the presence of high flow requirements and low pressure drop requirements. The previously described turboexpander 102 can be used as any turboexpander generator described throughout the present disclosure. System 200 includes a first turboexpander generator 102a, which defines a portion of a first pipeline flow channel 202a. The first turboexpander generator is configured to reduce the temperature or pressure of a process flow flowing through the first turboexpander generator 102a by generating electricity from the process flow. That is, the turboexpander generator converts the mechanical energy present in the fluid flow into electrical energy, and converts a specified amount of energy to produce a fluid condition specified for a downstream user 204. In some embodiments, the downstream user includes a pipeline. Generally, the first turboexpander generator 102 a and the second turboexpander generator 102 b are configured to regulate (in whole or in part) a pressure or temperature specified by a downstream user 204 .

[0067] The second turboexpander generator 102b defines a portion of the second duct flow channel 202b. The first duct flow channel 202a and the second duct flow channel 202b (as well as the first turboexpander generator 102a and the second turboexpander generator 102b) are arranged to carry fluid flows in parallel with each other. Except for any differences described herein, the second turboexpander generator is consistent with or substantially similar to the first turboexpander generator 102a (for example, in terms of topology, performance characteristics and / or key dimensions, such as one or more of power output, electric stator size and / or electromagnetic characteristics, rotor magnetic characteristics and / or size, turbine impeller aerodynamic characteristics and / or size, turboexpander performance, housing aerodynamic characteristics and / or internal dimensions, total overall length, etc.). To the extent that the second turboexpander generator 102b is substantially similar but not consistent with the first turboexpander generator 1021, in some cases, the differences in performance and size can be within 10% of the performance and size of the first turboexpander generator 102a.

[0068] In some embodiments, additional parallel flow channels 202 are included within the system 200. For example, in some embodiments, the Joule-Thomson valve 206 defines a portion of a third conduit flow channel 202d. The third conduit flow channel 202d is arranged to flow or carry fluid in parallel with the first conduit flow channel 202a and the second conduit flow channel 202b.

[0069] In some embodiments, the system 200 may include more or fewer turboexpander generators. For example, in some embodiments, the third turboexpander generator 102c defines a portion of a fourth conduit flow channel 202c that is arranged to carry fluid flow in parallel with the first conduit flow channel 202a, the second conduit flow channel 202b, and the third conduit flow channel 202d. Although specific examples and arrangements are described throughout this disclosure, any number of turboexpander generators 102 and Joule-Thomson valves 206 may be arranged in parallel with each other without departing from this disclosure.

[0070] Regardless of the number of turboexpander generators used, in some embodiments, all or some of the turboexpander generators include a flow control valve 208. Regardless of which turboexpander generator 102 is connected in series with the flow control valve 208, the flow control valve 208 regulates the flow through the turboexpander generator 102. The flow control valve 208 may be included upstream or downstream of the turboexpander generator 102, which is regulated by the flow control valve. For example, the first flow control valve 208a is located upstream of the first turboexpander generator 102a and (in whole or in part) regulates the flow through the first turboexpander generator 102a. Alternatively or additionally, in some embodiments, the second flow control valve 202b is located upstream of the second turboexpander generator 102b. The second flow control valve 208b regulates the flow through the second turboexpander generator 102b.

[0071] Figure 3 1 is a schematic block diagram of an example system 300 arrangement including two turboexpander generators (102a, 102b) connected in parallel pipes to each other. The system includes a controller 118. The controller 118 is coupled to various components within the system 300, such as the turboexpander generator 102, the flow control valve 208, various sensors 302, and the power grid 140. In operation, the controller is configured to receive a data stream indicating a process condition downstream of the first turboexpander generator 102a and the second turboexpander generator 102b. The controller 118 is configured to regulate the first turboexpander generator 102a and the second turboexpander generator 102b. For example, in some cases, the controller 118 adjusts the flow rate through the flow control valve 208 based on one or more specified or required downstream conditions. In some cases, the controller 118 adjusts the electrical load on one or more turboexpander generators 102 based on one or more specified or required downstream conditions.

[0072] In some embodiments, the controller is configured to regulate the power generated by the first turboexpander generator 102a and the second turboexpander generator 102b. For example, in some embodiments, the controller adjusts the voltage, current, or phase of the power generated by the turboexpander generator 102. Such regulation then allows the controller to direct the same-phase power to the grid.

[0073] Figure 4 is a block diagram of an example controller 118 that may be used in the context of the present disclosure. The controller 118 may, among other things, monitor parameters of the system and send signals to initiate and / or adjust various operating parameters of the system. Figure 4 As shown, in some cases, the controller 118 includes a processor 450 (e.g., implemented as one or more processors) and a memory 452 (e.g., implemented as one or more memories), the memory 452 containing instructions that cause the processor 450 to perform the operations described herein. The processor 450 is connected to an input / output (I / O) interface 454 for sending and receiving communications with components in the system (including, for example, sensors 302). In some cases, the controller 118 can additionally communicate status and send start and / or control signals with one or more of the various system components of the system 100 (including the flow control valve 208) and other sensors 302 (e.g., pressure sensors, temperature sensors, vibration sensors, and other types of sensors) provided in any system described herein. In some cases, the controller 118 can communicate status with one or more components within the system (e.g., the flow control valve 208) and send start and control signals thereto. The communication or communication can be wired, wireless, or a combination of wired and wireless. In some embodiments, controllers similar to controller 118 may be located elsewhere, such as in a data cart, elsewhere at the site, or even elsewhere remote from the site. In some embodiments, controller 118 may be a distributed controller, with different parts located around the site or off-site. For example, in some cases, controller 118 may be located at turboexpander generator 102, or controller 118 may be located in a separate control room or data cart. Additional controllers may be used throughout the site as stand-alone controllers or network controllers without departing from the present disclosure.

[0074] The controller 118 can operate in monitoring, commanding, and using the turboexpander generator 102 for adjusting process conditions and generating electricity for the downstream user 204. To monitor and control the turboexpander generator 102, the controller 118 is used in conjunction with various sensors located at both the turboexpander generator and the downstream user. The input signals and output signals (including data from the sensors) controlled and monitored by the controller 118 can be continuously recorded by the controller 118.

[0075] The controller 118 may have different levels of autonomy for controlling the turboexpander generator 102. For example, the controller 118 may begin sensing a change in a process condition of the downstream user 204, and the operator adjusts the flow control valve 208 or the electrical load of the turboexpander generator 102. Alternatively, the controller 118 may begin sensing a change in a process condition of the downstream user 204, receive additional input from the operator, and begin adjusting the flow control valve 208 or the electrical load of the turboexpander generator 102 without further input from the operator. Alternatively, the controller 118 may begin sensing a change in a process condition of the downstream user 204, and adjust the flow control valve 208 or the electrical load of the turboexpander generator 102 without input from the operator.

[0076] Figure 55 is a perspective view of an example system 500 arrangement including two turboexpander generators 102 connected in series with each other. That is, the fluid flows through the first turboexpander generator 102d and then flows through the second turboexpander 102e. During normal operation, the fluid flow always passes through the first turboexpander generator 102d and the second turboexpander 102e in sequence. In some embodiments, this arrangement is used in the presence of high pressure drop requirements. Except for any differences described herein or shown in the relevant figures, the system 500 is substantially similar to the previously described system 500 and system 500. In some embodiments, the first turboexpander generator 102d and the second turboexpander generator 102e are substantially similar in terms of key dimensions and performance indicators. In some embodiments, the first turboexpander generator 102d and the second turboexpander generator 102e are different in terms of key dimensions and performance indicators. The first turboexpander generator 102d defines a first portion of the pipeline flow channel 502a, and the second turboexpander generator 102e defines a second portion of the pipeline flow channel 502a. The first and second portions of the conduit flow channel 502a are arranged to carry fluid flow in series with each other. The user 204 is located downstream of the first turboexpander generator 102d and the second turboexpander generator 102e. The first turboexpander generator 102d and the second turboexpander generator 102e are configured to (wholly or partially) regulate the pressure or temperature specified for the downstream user 204. It is worth noting that since the mass flow between the first turboexpander generator 102d and the second turboexpander generator 102e is equal, the first turboexpander generator 102d and the second turboexpander generator 102e share the same flow control valve 208c.

[0077] Figure 6 6 is a schematic block diagram of an example system 600 arrangement including two turboexpander generators 102d and 102e connected in series with each other. In some embodiments, the Joule-Thomson valve 206 defines a third portion of the conduit flow channel 502a. The controller is configured to regulate the first turboexpander generator 102d and the second turboexpander generator 102e. The controller 118 is substantially similar to the controller 118 described previously.

[0078] Figure 7700 is a flow chart of an example method 700 that can be used with various aspects of the present disclosure. At 702, a first fluid stream is received by a first turboexpander generator. At 704, a second fluid stream is received by a second turboexpander generator. In some embodiments, the first turboexpander generator and the second turboexpander generator define a first portion and a second portion of a conduit flow channel. That is, the first portion and the second portion of the conduit flow channel are arranged to carry the fluid stream in series. In some embodiments, the first turboexpander generator and the second turboexpander generator are pipe-connected to the first conduit flow channel and the second conduit flow channel, respectively, and the first conduit flow channel and the second conduit flow channel are arranged to carry the fluid stream in parallel with each other.

[0079] In some embodiments, the first fluid stream and the second fluid stream include hydrocarbon gases. In some embodiments, the first fluid stream and the second fluid stream include hydrogen. In some embodiments, the first fluid stream and the second fluid stream include carbon dioxide gas. In some embodiments, the first fluid stream and the second fluid stream include air. Any high pressure gas with a pressure step-down requirement (e.g., gas from a pipeline entering a processing facility) can be decompressed or cooled by the turboexpander generator and arrangement described throughout the present disclosure.

[0080] Electricity is generated by at least one of the turboexpander generators. For example, in some embodiments, electricity is generated by a first generator. In some embodiments, electricity is generated by a second turboexpander generator. In some cases, generating electricity by any turboexpander generator includes: adjusting the flow through the turboexpander generator 102 based on specified downstream conditions, such as adjusting the flow through the turboexpander generator 102 by a flow control valve 208. In some cases, generating electricity includes: adjusting the electrical load of the turboexpander generator based on specified downstream conditions, such as adjusting the electrical load of the turboexpander generator by a controller 118 of the turboexpander generator. In some cases, generating electricity by any turboexpander generator can be stopped in response to changes in specified downstream conditions. For example, when the feed rate of the fluid drops below a specified threshold, electricity generation is stopped. When generating electricity, in some embodiments, the generated electricity is directed toward an electricity user separated from downstream users 204 of the first and second fluid flows.

[0081] Although some example embodiments have been described in which the turboexpander generator 102 is arranged in parallel or in series with other turboexpander generators 102 or Joule-Thomson valves 206, other arrangements are possible without departing from the present disclosure, such as adding additional turboexpander generators in parallel with turboexpander generators that are already arranged in series. Alternatively or additionally, additional turboexpander generators 102 may be added in series to a turboexpander 102 that is already arranged in parallel with another expander. In some embodiments, additional pressure regulators, such as Joule-Thomson valves 206 (or other regulators), may be added in parallel or in series with any turboexpander generator.

[0082] Various embodiments have been described. However, it should be understood that various modifications can be made without departing from the spirit and scope of the present disclosure. Therefore, other embodiments are also within the scope of the following claims.

Claims

1. A system comprising: a first turboexpander generator defining a portion of a first conduit flow path, the first turboexpander generator configured to reduce a temperature or pressure of a process stream flowing through the first turboexpander generator by generating electrical power from the process stream flowing through the first turboexpander generator; and a second turboexpander generator defining a portion of a second piping flow channel, the second turboexpander generator being configured to reduce a temperature or pressure of a process stream flowing through the second turboexpander generator by generating electrical power from the process stream flowing through the second turboexpander generator, the first piping flow channel and the second piping flow channel being arranged to carry fluid streams in parallel with each other, the first turboexpander generator and the second turboexpander generator being substantially identical in key dimensions and performance. 2 . The system of claim 1 , further comprising a controller configured to regulate the first turboexpander generator and the second turboexpander generator.

3. The system according to claim 1, wherein: The first turboexpander generator or the second turboexpander generator comprises: Rotor; a stator surrounding the rotor; carrying the rotor on a magnetic bearing within the stator, a portion of the magnetic bearing being supported by the stator; and A casing encloses the rotor and the stator, the casing being hermetically sealed between the inlet and outlet of each turboexpander generator.

4. The system according to claim 3, wherein: The inlet and the outlet of each turboexpander are centered about the same longitudinal axis of each turboexpander generator.

5. The system according to claim 3, wherein: The stator includes variable stator vanes configured to throttle fluid flow through the first turboexpander generator or the second turboexpander generator.

6. The system according to claim 1, further comprising: A first flow control valve upstream of the first turboexpander generator is configured to regulate flow through the first turboexpander generator.

7. The system according to claim 6, further comprising: A second flow control valve upstream of the second turboexpander generator is configured to regulate flow through the second turboexpander generator.

8. The system of claim 1, further comprising: A Joule-Thomson valve defines a portion of a third conduit flow channel arranged to carry fluid flow in parallel with the first conduit flow channel and the second conduit flow channel.

9. A method comprising: receiving a first fluid flow through a first turboexpander generator defining a portion of a first conduit flow path; as well as A second turboexpander generator receives the second fluid flow through a portion of a second conduit flow channel, the first and second conduit flow channels being arranged to carry the fluid flows in parallel, the first and second turboexpander generators being substantially identical in performance and critical dimensions.

10. The method according to claim 9, wherein: The first fluid stream and the second fluid stream include hydrocarbon gases.

11. The method according to claim 9, wherein: The first fluid stream and the second fluid stream include hydrogen.

12. The method according to claim 9, wherein: The first fluid stream and the second fluid stream include air.

13. The method according to claim 9, wherein: The first fluid stream flows through an annular space defined by a motorized rotor and a motorized stator of the first turboexpander generator.

14. The method according to claim 9, further comprising: Electricity is generated by the first turboexpander generator.

15. The method according to claim 9, further comprising: Electricity is generated by the second turboexpander generator.

16. The method according to claim 15, further comprising: Generation of electrical power by the first turboexpander generator or the second turboexpander generator is ceased in response to a change in a specified downstream condition.

17. The method according to claim 9, wherein: Generating electrical power by the first turboexpander generator comprises: Based on specified downstream conditions, flow is adjusted by the flow control valve.

18. The method according to claim 9, further comprising: Electricity generated by the first turboexpander generator or the second turboexpander generator is directed toward a user of electricity separate from users of the first and second fluid streams.

19. A system comprising: a first turboexpander generator defining a portion of a first conduit flow path, the first turboexpander generator configured to reduce a temperature or pressure of a process stream flowing through the first turboexpander generator by generating electrical power from the process stream flowing through the first turboexpander generator; a second turboexpander generator defining a portion of a second conduit flow channel, the second turboexpander generator being configured to reduce a temperature or pressure of a process stream flowing through the second turboexpander generator by generating electrical power from the process stream flowing through the second turboexpander generator, the first conduit flow channel and the second conduit flow channel being arranged to carry fluid streams in parallel with each other, the first turboexpander generator and the second turboexpander generator being substantially identical in key dimensions and performance; a Joule-Thomson valve defining a portion of a third conduit flow channel, the first conduit flow channel, the second conduit flow channel, and the third conduit flow channel being arranged to carry fluid flow in parallel with each other; and A controller is configured to regulate the first turboexpander generator and the second turboexpander generator.

20. The system of claim 19, wherein: The first turboexpander generator or the second turboexpander generator each comprises: Rotor; a stator surrounding the rotor; carrying the rotor on a magnetic bearing within the stator, a portion of the magnetic bearing being supported by the stator; and A casing encloses the rotor and the stator, the casing being hermetically sealed between the inlet and outlet of each turboexpander generator.

21. The system of claim 20, wherein: The stator includes variable stator vanes configured to throttle fluid flow through the first turboexpander generator or the second turboexpander generator.

22. The system of claim 19, further comprising: a first flow control valve upstream of the first turboexpander generator, the first flow control valve configured to regulate flow through the first turboexpander generator; and A second flow control valve upstream of the second turboexpander generator is configured to regulate flow through the second turboexpander generator.

23. The system of claim 19, further comprising a third turboexpander generator defining a portion of a fourth conduit flow path.

24. The system of claim 23, wherein: The fourth conduit flow channel is arranged to carry fluid flow in parallel with the first conduit flow channel, the second conduit flow channel, and the third conduit flow channel.

25. The system of claim 23, wherein: The fourth conduit flow channel is arranged in series with the first conduit flow channel.

26. The system of claim 19, wherein: The controller is also configured to: receiving a data stream indicative of a process condition downstream of the first turboexpander generator and the second turboexpander generator; and The flow rate is regulated by the flow control valve based on one or more specified downstream conditions.

27. The system of claim 19, wherein: The controller is also configured to: regulating the electrical power generated by the first turboexpander generator and the second turboexpander generator; and The electrical power is directed into a grid, the electrical power being in phase with the grid.

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