Expansion and compression dual-purpose turbomachinery and design method

Abstract

The invention discloses an expansion and compression dual-purpose turbo machine which comprises a pressing shell, a first connecting port, a second connecting port, an expansion device and a compression device, the pressing shell is provided with a first connecting port and a second connecting port, and a circulation channel is formed in the pressing shell from the first connecting port to the second connecting port; the rotating wheel is arranged in the circulation channel of the pressing shell; when gas flows in from the first connector and flows out from the second connector, the rotating wheel rotates in the first direction, and the gas is compressed; when gas flows in from the second connector and flows out from the first connector, the rotating wheel rotates in the second direction, and the gas expands; the first direction and the second direction are opposite to each other. The invention further provides a design method of the turbomachinery. The single machine can bear two functions of gas compression and gas expansion, and the system is simplified.

Description

Technical Field

[0001] The present invention relates to the technical field of gas compression, and in particular to a turbine machine capable of both expansion and compression. Background Art

[0002] Traditional turbine machinery is typically designed for a single function, meaning it can only be used for compression or expansion. For example, a compressor is used to increase gas pressure, while an expander is used to extract energy from high-pressure gas. However, in certain application scenarios, turbine machinery needs to be able to switch operating modes under different operating conditions and maintain high efficiency. For example, in a compressed air energy storage system (CAES), the impeller needs to work as a compressor during the energy storage phase; during the energy release phase, the impeller needs to work as an expander to achieve peak load shifting for the power grid.

[0003] Prior art designs for bidirectional impellers utilize dual-unit systems, employing separate compressors and expanders to perform compression and expansion, respectively. These independent units are expensive and require significant floor space. Consequently, the prior art lacks a single-unit turbine engine capable of achieving high efficiency in both compression and expansion modes.

[0004] Furthermore, in the field of turbomachinery, impellers are core components of equipment such as compressors, expanders, and turbines, and their design directly impacts the energy conversion efficiency of these devices. Traditional impeller designs typically target a single operating condition, such as compression or expansion, and lack design methods for impellers operating in both directions.

[0005] Therefore, technicians in this field are committed to providing a turbine machine and design method for both expansion and compression, so that a single machine can undertake both gas compression and expansion working conditions. Summary of the Invention

[0006] In view of the defects in the prior art, the technical problem to be solved by the present invention is how to provide a turbine machine that can realize the gas compression and expansion functions of a single machine.

[0007] To achieve the above object, the present invention provides a dual-purpose expansion and compression turbine machine, comprising:

[0008] A compression shell having a first interface and a second interface, wherein a flow channel is formed inside the compression shell from the first interface to the second interface;

[0009] a rotating wheel disposed in the flow channel of the compression shell;

[0010] When gas flows in from the first interface and flows out from the second interface, the rotating wheel rotates in the first direction and the gas is compressed;

[0011] When gas flows in from the second interface and flows out from the first interface, the rotating wheel rotates in the second direction and the gas expands;

[0012] The first direction and the second direction are opposite to each other.

[0013] Furthermore, it further includes a motor, the rotating shaft of the motor is axially connected to the rotating wheel, and the motor drives the rotating wheel to rotate along the first direction.

[0014] Furthermore, when the rotating wheel rotates along the second direction, the motor is in a power generation state.

[0015] Furthermore, a first blade and a second blade distributed along the circumference are provided on the disk surface of the rotating wheel, and the first blade is located on the inner side of the second blade.

[0016] Furthermore, the height of the first blade is greater than the height of the second blade.

[0017] Furthermore, the inlet and outlet installation angles β1 and β2 of the first blade satisfy: β1<β2; the inlet and outlet installation angles α1 and α2 of the second blade satisfy: α1<α2.

[0018] Preferably, a thrust plate and a thrust bearing are provided between the rotating shaft and the rotating wheel.

[0019] Preferably, both ends of the rotating shaft are respectively connected to a group of the compression shell and the rotating wheel.

[0020] The present invention also provides a design method for a dual-purpose expansion and compression turbine machine, which is used to design the turbine machine, comprising:

[0021] In compression mode, calculating the inlet and outlet installation angles β1 and β2 of the first blade and the inlet and outlet installation angles α1 and α2 of the second blade;

[0022] In the expansion mode, calculating the inlet and outlet installation angles β1' and β2' of the first blade and the inlet and outlet installation angles α1' and α2' of the second blade;

[0023] According to the intersection, the ranges of the first blade inlet and outlet installation angles and the second blade inlet and outlet installation angles are obtained: β1-β1', β2-β2', α1-α1', α2-α2'.

[0024] Preferably, the method further comprises: optimizing the first blade and the second blade according to a target compression efficiency and a target expansion efficiency.

[0025] The present invention has at least the following beneficial technical effects:

[0026] The dual-purpose expansion and compression turbine provided by this invention integrates a blade diffuser and nozzle into one unit, capable of guiding gas in both modes. This single unit can perform both gas compression and expansion functions, simplifying the system, reducing footprint, and lowering costs. The symmetrical arrangement of the two impellers ensures consistent gas pressure at both ends, self-balancing axial forces. This means the thrust bearing only needs to balance the minor axial forces caused by component differences, further reducing costs and enhancing safety and reliability.

[0027] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 1 is a schematic diagram of a dual-purpose expansion and compression turbine in compression mode according to an embodiment of the present invention;

[0029] Figure 2 1 is a schematic diagram of a dual-purpose expansion and compression turbine machine in an expansion mode according to an embodiment of the present invention;

[0030] Figure 3 is a side view of a rotating wheel according to an embodiment of the present invention;

[0031] Figure 4 is a top view of a rotating wheel according to an embodiment of the present invention;

[0032] Figure 5 It is a schematic diagram of the design process of a turbine machinery for expansion and compression according to an embodiment of the present invention.

[0033] In the figure, 1-compression casing, 2-compression wheel, 3-blade diffuser, 4-rotating shaft, 5-motor stator, 6-thrust plate, 7-thrust bearing, 8-volute, 9-turbine, 10-nozzle, 11-first blade, 12-second blade. DETAILED DESCRIPTION

[0034] The following describes preferred embodiments of the present invention to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0035] In the drawings, components with identical structures are denoted by the same reference numerals, and components with similar structures or functions are denoted by similar reference numerals. The size and thickness of each component shown in the drawings are arbitrary and are not limited by the present invention. For clarity, the thickness of components in some places in the drawings is appropriately exaggerated.

[0036] The present invention provides a turbine machine for both expansion and compression, which can undertake both gas compression and expansion functions through a single machine, thereby simplifying the system and reducing costs under bidirectional working conditions.

[0037] The present invention provides a dual-purpose expansion and compression turbine engine comprising a compression housing having a first interface and a second interface. A flow channel is formed within the compression housing from the first interface to the second interface, and a rotating wheel is disposed within the flow channel. When gas flows in through the first interface and out through the second interface, the rotating wheel rotates in a first direction, compressing the gas. When gas flows in through the second interface and out through the first interface, the rotating wheel rotates in a second direction, expanding the gas. The first and second directions are opposite to each other and can be simply described as forward and reverse directions.

[0038] To achieve rotation of the rotating wheel in the first direction, the present invention further includes a motor having a motor stator and a rotating shaft, the end of the rotating shaft being connected to the rotating wheel. When the motor is powered by external electricity, it operates as a motor, and the rotating shaft drives the rotating wheel to rotate, thereby compressing the gas. When the motor is not powered by external electricity, and compressed gas flows in through the second port, it expands, and the rotating wheel rotates in the opposite direction, causing the magnetic rotating shaft to cut through the magnetic flux lines, generating current in the motor stator and outputting electrical energy.

[0039] like Figure 1 and Figure 2 As shown in FIG, the turbine machinery of the present invention is respectively a schematic diagram of working in compression mode and expansion mode. Because the turbine machinery works in different modes, the names of the parts are also different.

[0040] In such Figure 1 In the compression mode shown, the motor stator 5 is energized, driving the rotating shaft 4 to rotate, and the low-temperature gas enters the compression shell 1 from the first interface. The gas passes through the compression wheel 2 and the blade diffuser 3 on the rotating wheel, and outputs high-temperature and high-pressure gas; the input electrical energy is converted into mechanical energy of the gas and stored.

[0041] In such Figure 2 In the expansion mode shown, high-temperature, high-pressure gas enters volute 8 from the second port, passes through nozzle 10 and turbine 9 on the rotor, and expands in turbine 9, generating work and driving turbine 9 to rotate. This in turn drives shaft 4, which cuts through magnetic flux lines, generating current in motor stator 5 and outputting electrical energy. Thus, the energy stored in the gas is converted into electrical energy through expansion.

[0042] like Figure 1 and Figure 2As shown, a thrust plate 6 and a thrust bearing 7 are provided between the rotating shaft 4 and the rotating wheel to balance the thrust on the rotating shaft 4. To better balance the thrust, a set of compression shells and rotating wheel devices are provided at each end of the rotating shaft 4. This way, the thrust of the two rotating wheels can be balanced. However, due to machining deviations, there is still a certain difference in the thrust at the two ends, so only a smaller thrust plate 6 and thrust bearing 7 are required to achieve balance.

[0043] like Figure 3 and Figure 4 The figure shows a schematic diagram of the rotor structure of this embodiment. The rotor comprises a disk with first blades 11 and second blades 12 distributed circumferentially on its surface, with the first blades 11 located inward of the second blades 12. The first blades 11 are impellers. In compression mode, they function as impellers 2, compressing the gas; in expansion mode, they function as turbines 9, expanding the gas and producing work. The second blades 12 are guide vanes. In compression mode, they function as vane diffusers 3, guiding and diffusing the gas, converting dynamic pressure into static pressure; in expansion mode, they function as nozzles 10, guiding the gas, converting static pressure into dynamic pressure.

[0044] In this embodiment, the first blade 11 has a three-dimensional twisted airfoil shape. Specifically, the inlet and outlet installation angles β1 and β2 of the first blade 11 satisfy the following: β1 < β2, and the inlet and outlet installation angles α1 and α2 of the second blade 12 satisfy the following: α1 < α2. The impeller and guide vanes need to switch between compression and expansion modes. The inlet and outlet installation angles of the impeller and guide vanes have the greatest impact on machine efficiency. Therefore, it is necessary to obtain appropriate angles to achieve high efficiency in both compression and expansion modes.

[0045] like Figure 5 The diagram shows a schematic diagram of an optimization method for a dual-purpose expansion and compression turbine machinery according to an embodiment of the present invention. The main optimization process is as follows.

[0046] According to the inlet and outlet gas design targets in compression mode, the impeller, guide vanes, and compressor casing are generated, and the inlet and outlet installation angles β1 and β2 of the impeller and the inlet and outlet installation angles α1 and α2 of the guide vanes are calculated;

[0047] Based on the inlet and outlet gas design targets in the expansion mode, the impeller, guide vanes, and volute are generated, and the inlet and outlet installation angles β1' and β2' of the impeller and the inlet and outlet installation angles α1' and α2' of the guide vanes are calculated.

[0048] According to the intersection, the ranges of the impeller inlet and outlet installation angles and the guide vane inlet and outlet installation angles are obtained: β1-β1', β2-β2', α1-α1', and α2-α2'.

[0049] The impeller and guide vanes can be further optimized according to the target compression efficiency and target expansion efficiency.

[0050] Taking the design objectives shown in Table 1 as an example, according to the above design method, the guide vane and impeller angle ranges shown in Table 2 are obtained.

[0051] Table 1

[0052]

[0053] Table 2

[0054]

[0055]

[0056] The simulation results for the above parameters confirmed the feasibility of the optimization method: in compression mode, the design target was achieved, with a speed of 30,000 rpm and a volume flow rate of 120m 3 / min, pressure ratio 2.2, isentropic efficiency 80%; in expansion mode, the design target was achieved, with a speed of 22,000 rpm and a volume flow rate of 50m 3 / min, an expansion ratio of 2.2, and an isentropic efficiency of 83%. This turbine machine can maintain high efficiency in both modes, and the same machine can perform both compression and expansion functions.

[0057] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A turbine machine capable of both expansion and compression, characterized in that: include: A compression shell having a first interface and a second interface, wherein a flow channel is formed inside the compression shell from the first interface to the second interface; a rotating wheel disposed in the flow channel of the compression shell; When gas flows in from the first interface and flows out from the second interface, the rotating wheel rotates in the first direction and the gas is compressed; When gas flows in from the second interface and flows out from the first interface, the rotating wheel rotates in the second direction and the gas expands; The first direction and the second direction are opposite to each other.

2. The dual-purpose expansion and compression turbine machine according to claim 1, characterized in that: It also includes a motor, a rotating shaft of the motor is axially connected to the rotating wheel, and the motor drives the rotating wheel to rotate along the first direction.

3. The expansion and compression dual-purpose turbine machine according to claim 2, characterized in that: When the rotating wheel rotates along the second direction, the motor is in a power generation state.

4. The dual-purpose expansion and compression turbine machine according to claim 1, characterized in that: A first blade and a second blade are provided on the disk surface of the rotating wheel and are distributed along the circumference. The first blade is located on the inner side of the second blade.

5. The expansion and compression dual-purpose turbine machine according to claim 4, characterized in that: The height of the first blade is greater than the height of the second blade.

6. The expansion and compression dual-purpose turbine machine according to claim 5, characterized in that: The inlet and outlet installation angles β1 and β2 of the first blade satisfy: β1<β2; the inlet and outlet installation angles α1 and α2 of the second blade satisfy: α1<α2.

7. The expansion and compression dual-purpose turbine machine according to claim 2, characterized in that: A thrust plate and a thrust bearing are provided between the rotating shaft and the rotating wheel.

8. The dual-purpose expansion and compression turbine machine according to claim 7, characterized in that: Two ends of the rotating shaft are respectively connected to a group of the compression shells and the rotating wheels.

9. A method for designing a dual-purpose expansion and compression turbine machine, used for designing a turbine machine according to any one of claims 1 to 8, characterized in that: include: In compression mode, calculating the inlet and outlet installation angles β1 and β2 of the first blade and the inlet and outlet installation angles α1 and α2 of the second blade; In the expansion mode, calculating the inlet and outlet installation angles β1' and β2' of the first blade and the inlet and outlet installation angles α1' and α2' of the second blade; According to the intersection, the ranges of the first blade inlet and outlet installation angles and the second blade inlet and outlet installation angles are obtained: β1-β1', β2-β2', α1-α1', α2-α2'.

10. The design method of a dual-purpose expansion and compression turbine machine according to claim 9, characterized in that: Also includes: The first blade and the second blade are optimized according to target compression efficiency and target expansion efficiency.

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