A new turbine expansion power generation integrated machine

Abstract

The application relates to the technical field of turboexpansion generators, and discloses a novel turboexpansion generator integrated machine, which comprises, in sequence, an air inlet cavity section, an expander cavity section, a generator cavity section and a gas collection cavity section; the air inlet cavity section is used for inputting working gas; the expander cavity section is used for expanding and working the working gas; a nozzle and an impeller are sequentially arranged in the expander cavity section, the working gas is sprayed from the nozzle to the impeller and drives the impeller to rotate; a main shaft is arranged in the generator cavity section, a rotor and a stator are arranged on the main shaft; the impeller is used for synchronously driving the main shaft to rotate so as to realize power generation of the generator; a first gas hole is arranged on a first cover plate, the working gas passing through the first gas hole respectively flows to a first gap and a second gap according to a preset ratio; and the gas collection cavity section is used for collecting the working gas flowing out of the generator cavity section and discharging the working gas. The novel turboexpansion generator integrated machine has good self-heat-dissipation performance, does not need to additionally arrange a cooling device, has a simple structure, a small volume and good operation stability.

Description

Technical Field

[0001] This invention relates to the field of turbine expander generator technology, and specifically to a novel integrated turbine expander generator. Background Technology

[0002] With increasingly stringent emission standards for ships, LNG-powered ships are gaining popularity among ship owners, and the number of LNG-powered ships is increasing year by year.

[0003] LNG-powered ships use LNG (liquefied natural gas) as their power source. When LNG is vaporized for use as fuel in a ship's propulsion system, it needs to absorb heat from the environment. Currently, cryogenic organic Rankine cycle (CRRC) power generation systems are commonly used for LNG vaporization. This system not only vaporizes LNG but also generates electricity, fully utilizing the waste heat resources of LNG to achieve power generation and achieving a high energy efficiency. In a conventional cryogenic organic Rankine cycle power generation system, the key equipment is an expander and a generator. The expander achieves energy conversion through the expansion of high-pressure gas. The pressurized gas undergoes adiabatic expansion within the turbine expander, doing work while consuming its own internal energy. This process cools the gas while simultaneously outputting energy, and the work done by the gas drives the generator to operate, thus generating electricity.

[0004] However, existing low-temperature organic Rankine cycle power generation devices require additional auxiliary devices such as speed reduction devices, sealing devices, and cooling devices to ensure stable operation in practical applications. This results in a complex overall structure and a large system footprint. To address this, there is also an integrated expander-generator, which combines the expander and generator. While this simplifies the structure, the overall heat dissipation performance is poor, the generator is prone to overheating, and stability is compromised.

[0005] Therefore, it is essential to design a turbine expander generator with a simple and compact structure, good heat dissipation, and high stability suitable for use on LNG-powered ships for LNG cold energy power generation. Summary of the Invention

[0006] The present invention aims to provide a novel integrated turbine expander generator with good self-heating performance, no need for additional cooling devices, simple structure, small size, and good operational stability.

[0007] The basic solution provided by this invention is as follows: a novel integrated turbine expander generator, comprising an intake chamber, an expander chamber, a generator chamber, and a gas collecting chamber arranged sequentially; the intake chamber is used to input working gas; the expander chamber is used to expand the working gas to perform work; a first cover plate is provided between the expander chamber and the generator chamber, and the expander chamber is composed of an expander shell and the first cover plate; a nozzle and an impeller are arranged sequentially in the expander chamber, and the working gas is sprayed from the nozzle to the impeller and drives the impeller to rotate;

[0008] The generator chamber is equipped with a main shaft, on which a rotor and a stator are mounted. The impeller is used to synchronously drive the main shaft to rotate, thereby generating electricity. The first cover plate is provided with a first vent hole, through which the working gas flows to a first gap and a second gap in a preset ratio. The first gap is the space between the rotor and the stator. The second gap is the space between the stator and the generator housing. The rotor is provided with a rotor ventilation groove along the axis of the main shaft, and the stator is provided with a stator ventilation groove along the axis of the main shaft. The gas collecting chamber is used to collect and discharge the working gas flowing out of the generator chamber.

[0009] The working principle and advantages of this invention are as follows: the working gas flows sequentially from the inlet section through the expander section, the generator section, and the gas collecting section, and is discharged through the gas collecting section. Specifically, the working gas is sprayed from the nozzle in the expander section onto the impeller, driving the impeller to rotate. The rotation of the impeller synchronously drives the main shaft of the generator section, thereby generating electricity. The working gas flowing through the impeller enters the generator section through the first gas hole and splits into two parts, flowing into the first gap and the second gap respectively. During this process, the working gas circulates in the first and second gaps, which helps to dissipate heat. Furthermore, the rotor ventilation slots and stator ventilation slots further expand the gap space, increasing the contact area between the working gas and the rotor, stator, etc., further improving the heat dissipation effect.

[0010] This invention presents a novel integrated turbine expander generator, which combines the expander and generator into a single unit. The overall structure is simple, compact, and occupies minimal space. Furthermore, the flow of the working gas in this design is entirely within a sealed casing, eliminating leakage and ensuring good operational stability. Notably, this design specifically controls the flow of the working gas into the generator chamber, directing it to different gap spaces according to a preset ratio. It also features groundbreaking adjustments to the stator and rotor structures, expanding the gap spaces to allow the working gas to effectively cool the generator's heat source, resulting in superior cooling without the need for additional cooling devices.

[0011] Furthermore, compared to conventional methods for handling the working gas after it passes through the impeller—where the conventional method often directly leads the working gas to the external space or allows it to flow along the gaps at the edge of the casing to the outlet—the former wastes the cooling energy of the working gas after expansion and work, while the latter fails to fully utilize this energy, leaving the areas in the generator with the most severe heat accumulation untreated. This design, however, guides the gas in a directional manner and, through structural improvements, ensures that the gas's cooling energy is fully utilized and applied to critical areas. This maximizes the use of the working gas, achieving superior cooling, preventing overheating during generator operation, and enabling long-term stable operation. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of an embodiment of a novel integrated turbine expander generator according to the present invention;

[0013] Figure 2 This is a schematic diagram of the working gas flow direction in an embodiment of a novel integrated turbine expander generator of the present invention;

[0014] Figure 3 This is a partial structural schematic diagram of the rotor and stator of a novel integrated turbine expander generator according to an embodiment of the present invention. Detailed Implementation

[0015] The following detailed explanation illustrates the specific implementation methods:

[0016] The markings in the accompanying drawings include: intake chamber section 1, intake chamber shell 11, intake chamber inlet 111, guide shroud 12, turbine expander 2, expander chamber section 21, expander shell 22, nozzle 23, impeller 24, generator 3, generator chamber 31, guide plate 311, generator shell 32, rotor 33, rotor ventilation slot 331, stator 34, stator ventilation slot 341, stator coil slot 342, stator coil 343, gas collecting chamber section 4, gas collecting chamber shell 41, gas collecting chamber outlet 411, main shaft 5, first bearing 51, second bearing 52, first cover plate 6, and second cover plate 7.

[0017] The basic implementation examples are as follows: Figure 1 As shown: A novel integrated turbine expander generator includes an air intake section 1, an expander section 21, a generator section 31, and an air collection section 4 arranged sequentially.

[0018] The air intake section 1 is used to input the working gas. The air intake section 1 is enclosed by an air intake shell 11, and an air intake inlet 111 is provided on the air intake shell 11. The air intake section 1 converges along the flow direction of the working gas. The air intake inlet 111 is connected to a gas delivery pipe, which is used to deliver the working gas. In this embodiment, the working gas is a mixture of methane, ethane, propane, and butane, wherein the molar ratio of methane is 0.5, the molar ratio of ethane is 0.3, the molar ratio of propane is 0.15, and the molar ratio of butane is 0.05; the working gas has stable characteristics, making the overall device operation more stable. A flow guide shroud 12 is provided inside the air intake section 1, and the flow guide shroud 12 is coaxial with the main shaft 5. The working gas is guided to the nozzle 23 through the flow guide shroud 12.

[0019] The expander chamber section 21 is used to expand the working gas to perform work. A first cover plate 6 is provided between the expander chamber section 21 and the generator chamber section 31. The expander chamber section 21 is composed of an expander housing 22 and the first cover plate 6. A nozzle 23 and an impeller 24 are sequentially arranged in the expander chamber section 21. The working gas is sprayed from the nozzle 23 to the impeller 24 and drives the impeller 24 to rotate. Specifically, the turbine expander 2 structure includes the first cover plate 6, the expander housing 22, the nozzle 23, the impeller 24, and the main shaft 5. In this embodiment, the turbine expander 2 and the generator 3 share a main shaft 5.

[0020] The impeller 24 is an axial flow impeller 24; and an arc-shaped flow channel is formed between any two blades of the impeller 24; it is suitable not only for small power generation devices, but also for large power generation devices, and has strong versatility. The nozzle 23 blade cascade and the impeller 24 blade cascade are arranged in a ring. When selecting the blade cascade, the pressure ratio before and after the nozzle 23 blade cascade determines whether the working fluid flows in the nozzle 23 at supersonic speed, and then the type of nozzle 23 blade cascade is selected (a subsonic blade cascade is used here, and it is arranged in a ring); according to the pressure ratio before and after the impeller 24 moving blade cascade, the type of impeller 24 moving blade cascade is determined (a reaction subsonic blade cascade is used here, and it is arranged in a ring), and the reaction degree of the working fluid airflow in the impeller 24 moving blade cascade is set; in this embodiment, the reaction degree at the root of the impeller 24 blade is 0.04.

[0021] A second cover plate 7 is provided between the generator cavity 31 and the gas collecting cavity 4; the generator cavity 31 is composed of a generator housing 32, a first cover plate 6, and a second cover plate 7. A main shaft 5 is provided in the generator cavity 31, and a rotor 33 and a stator 34 are mounted on the main shaft 5; the rotor 33 has a rotor ventilation slot 331 along the axis of the main shaft 5, and the stator 34 has a stator ventilation slot 341 along the axis of the main shaft 5. Specifically, the generator 3 structure includes: a rotor 33, a stator 34, a generator housing 32, a first cover plate 6, and a second cover plate 7. The first cover plate 6 and the second cover plate 7, together with the generator housing 32, form the generator cavity 31. The expander cavity 21 is connected to the generator cavity 31 via a first air hole on the first cover plate 6.

[0022] The impeller 24 is used to synchronously drive the main shaft 5 to rotate so as to realize the power generation of the generator 3; the impeller 24 is sleeved on the main shaft 5 and fixedly connected to the main shaft 5. The impeller 2423 can rotate at high speed around the axis of the main shaft 5 under the push of the expanding working gas flow, and synchronously drive the main shaft 5 to rotate at high speed.

[0023] Specifically, the main shaft 5 is located in the generator 3 section, and its material is magnetic steel. In this embodiment, the generator 3 is a permanent magnet synchronous generator 3. The stator 34 is equipped with an armature winding. After the generator 3 is connected to a symmetrical load, the rotating magnetic field generated by the three-phase current in the armature winding rotates at the same speed as the rotor 33. The rotor 33 adopts a salient pole structure; the permanent magnets are attached to the surface of the rotor 33 core, and the permanent magnets are installed in a surface-mounted manner. The relative permeability of the permanent magnets is close to 1, the air gap is uniform, and the magnetic reluctance of the quadrature and direct axis magnetic circuits is the same. The gap between adjacent permanent magnets of the rotor 33 is the same, and the gap between adjacent permanent magnets serves as the rotor ventilation slot 331, as shown in the attached figure. Figure 3 As shown, the working gas flows in the rotor ventilation slot 331 to cool the rotor 33.

[0024] The stator ventilation slot 341 is located on the surface of the stator 34 opposite to the rotor 33. The stator 34 also has a stator coil slot 342 for housing the stator coil 343. The stator ventilation slot 341 is located at the bottom of the stator coil slot 342, and the working gas circulates within the stator ventilation slot 341 to cool the stator 34 and the stator coil 343. Several stator ventilation slots 341 and rotor ventilation slots 331 are evenly distributed around the main shaft 5.

[0025] The first cover plate 6 has a first vent hole, and the working gas passing through the first vent hole flows to the first gap and the second gap respectively according to a preset ratio; the first gap is the gap space between the rotor 33 and the stator 34, including the stator ventilation slot 341, the rotor ventilation slot 331, etc.; the second gap is the gap space between the stator 34 and the generator housing 32.

[0026] A guide plate 311 is provided inside the generator cavity 31. The guide plate 311 is used to guide the working gas to flow in a preset ratio. The preset ratio is the amount of working gas flowing to the first gap: the amount of working gas flowing to the second gap. One end of the guide plate 311 is located at the first vent and divides the space of the first vent into two parts, and this end is also fixedly connected to the first cover plate 6. The other end of the guide plate 311 is located on the end face of the stator 34 and is fixedly connected to the end face of the stator 34. The guide plate 311 has a stable structure and a more stable guiding effect. The axis of the guide plate 311 is at a preset angle to the axis of the first vent. The preset angle is 60 degrees to 85 degrees.

[0027] The main shaft 5 is also provided with a first bearing 51 and a second bearing 52; the first bearing 51 is located at the first cover plate 6 and can apply axial force and radial force to the main shaft 5; the first bearing 51 is composed of a radial bearing and a thrust bearing; the radial bearing is a magnetic levitation bearing and can control the radial displacement of the main shaft 5 by electromagnetic force; the thrust bearing is a magnetic levitation bearing and can limit the axial displacement of the main shaft 5 by electromagnetic force.

[0028] Furthermore, a non-contact differential inductive displacement sensor is installed at the magnetic levitation bearing. The current of the electromagnet coil in the magnetic levitation bearing is controlled by a controller, which simultaneously establishes a communication connection with the non-contact differential inductive displacement sensor. During the operation of this integrated turbine expander generator, the displacement of the main shaft 5 is detected by the non-contact differential inductive displacement sensor. The detected displacement signal of the main shaft 5 is transmitted from the sensor to the controller. The controller can adjust the current of the electromagnet coil in the magnetic levitation bearing based on the displacement signal, thereby adjusting the force applied by the bearing to the main shaft 5 to ensure that the main shaft 5 maintains stable and safe rotation.

[0029] The gas collecting chamber section 4 is used to collect and discharge the working gas flowing out of the generator chamber section 31. The gas collecting chamber section 4 is surrounded by a gas collecting chamber shell 41 and a second cover plate 7. The gas collecting chamber shell 41 has a gas collecting chamber outlet 411. The gas collecting chamber outlet 411 is used to discharge the working gas. The second cover plate 7 has a second vent hole. The generator chamber section 31 and the gas collecting chamber section 4 are connected through the second vent hole on the second cover plate 7. The second bearing 52 is located at the second cover plate 7. The second bearing 52 can apply radial force to the main shaft 5; the second bearing 52 is a magnetically levitated radial bearing, which can control the radial displacement of the main shaft 5 by electromagnetic force.

[0030] As attached Figure 2 As shown, in a specific application, the working gas is input from the gas delivery pipeline through the inlet 111 into the inlet section 1. The working gas flows through the guide shroud 12 and is guided to the nozzle 23. The working gas enters the nozzle 23 and expands and accelerates within it. The nozzle 23 then ejects the expanded and accelerated high-speed working gas flow. This flow then acts on the impeller 24, which rotates at high speed around the axis of the main shaft 5 under the drive of the flow, and synchronously drives the main shaft 5 to rotate at high speed. During the rotation of the main shaft 5, the rotor 33 of the generator 3 rotates at high speed in the stator 34 of the generator 3. The stator 34 generates an induced current, outputs electricity, and generates a changing electromagnetic field, which brakes the rotation of the main shaft 5, thereby converting the mechanical energy of the rotation of the main shaft 5 into electrical energy, realizing power generation.

[0031] During this process, the working gas flow passing through the impeller 24 continues to flow to the first cover plate 6 and flows into the generator cavity 31 section through the first air hole; and the working gas flow is divided by the guide plate 311 and flows to the first gap and the second gap respectively according to a preset ratio. Specifically, the working gas flow to the first gap passes through the stator ventilation slot 341 and the rotor ventilation slot 331 to cool the rotor 33, stator 34 and stator coil 343; the working gas flow to the second gap passes through the stator 34 and the generator housing 32 to cool the stator 34 and the generator housing 32; then, the working gas reaches the second cover plate 7 and flows into the gas collecting cavity section 4 through the second air hole, and is discharged from the gas collecting cavity outlet 411.

[0032] This embodiment provides a novel integrated turbine expander generator with a simple overall structure, strong integration, and excellent cooling effect without the need for additional cooling devices. It can fully utilize the energy of the working gas, effectively prevent overheating of the generator 3, and exhibit good operational stability. Furthermore, this solution incorporates a non-contact differential inductive displacement sensor and controller at the magnetic levitation bearing of the main shaft 5. This allows for timely and accurate monitoring and adjustment of the main shaft 5's displacement, ensuring long-term stability of the main shaft 5's operation and further enhancing the operational stability of the generator 3.

[0033] Furthermore, the positions of the stator ventilation slot 341 and the rotor ventilation slot 331 in this scheme are selected based on the basic structure of the stator 34 and rotor 33 themselves. The ventilation slots are selected as the gap between adjacent permanent magnets and the adjacent part of the stator coil slot 342. This fully utilizes the structural features of the stator 34 and rotor 33 themselves, and the structural adjustment range is relatively small. This can effectively avoid the introduction of airflow from affecting the operation of the generator 3 and ensure the effective operation of the device.

[0034] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics of the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A novel integrated turbine expander generator, characterized in that, It includes an inlet chamber, an expander chamber, a generator chamber, and a gas collecting chamber arranged in sequence; the inlet chamber is used to input working gas; the expander chamber is used to expand the working gas to do work; a first cover plate is provided between the expander chamber and the generator chamber; the expander chamber is composed of an expander shell and the first cover plate; a nozzle and an impeller are arranged in sequence in the expander chamber, and the working gas is sprayed from the nozzle to the impeller and drives the impeller to rotate. The generator chamber contains a main shaft, on which a rotor and a stator are mounted. The impeller synchronously drives the main shaft to rotate, thereby generating electricity. The first cover plate has a first vent hole, through which the working gas flows to a first gap and a second gap in a preset ratio. The first gap is the space between the rotor and the stator; the second gap is the space between the stator and the generator housing. The rotor has a rotor ventilation slot along the axis of the main shaft, and the stator has a stator ventilation slot along the axis of the main shaft. The gas collecting chamber collects and discharges the working gas flowing out of the generator chamber. The generator is a permanent magnet synchronous generator; the rotor adopts a salient pole structure, with permanent magnets attached to the surface of the rotor core; the gap between adjacent permanent magnets of the rotor serves as a rotor ventilation slot; the stator ventilation slot is located on the surface of the stator opposite to the rotor; the stator is also provided with stator coil slots, which are used to accommodate the stator coils; the stator ventilation slots are located at the bottom of the stator coil slots. The generator cavity is equipped with a guide plate; the guide plate is used to guide the working gas to flow in a preset ratio; one end of the guide plate is located at the first gas hole, and the axis of the guide plate is at a preset angle to the axis of the first gas hole.

2. The novel integrated turbine expander generator according to claim 1, characterized in that, A second cover plate is provided between the generator section and the gas collecting section; a second air hole is provided on the second cover plate.

3. The novel integrated turbine expander generator according to claim 1, characterized in that, The preset angle is 60 degrees to 85 degrees.

4. The novel integrated turbine expander generator according to claim 1, characterized in that, The preset ratio is the amount of working gas flowing into the first gap: the amount of working gas flowing into the second gap.

5. A novel integrated turbine expander generator according to claim 1, characterized in that, The impeller is an axial flow impeller; and an arc-shaped flow channel is formed between any two blades of the impeller.

6. A novel integrated turbine expander generator according to claim 2, characterized in that, The main shaft is also provided with a first bearing and a second bearing; the first bearing is located at the first cover plate, and the second bearing is located at the second cover plate.

7. A novel integrated turbine expander generator according to claim 1, characterized in that, The air intake section is equipped with a flow guide; the working gas is guided to the nozzle through the flow guide.

8. A novel integrated turbine expander generator according to claim 1, characterized in that, The stator ventilation slot is located on the surface of the stator opposite to the rotor.

9. A novel integrated turbine expander generator according to claim 8, characterized in that, Both the stator ventilation slots and the rotor ventilation slots are provided with several slots evenly distributed along the circumference of the main shaft.

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