Compressor-expander unit for high-temperature heat pump and high-temperature heat pump energy storage system

Abstract

A compressor-expander unit for a high-temperature heat pump, the compressor-expander unit comprising a compressor and an expander. The compressor comprises a rotor assembly, a stator assembly, and a housing assembly, wherein the rotor assembly comprises multi-stage moving blades (25), an inlet angle of the moving blades (25) being set within a range of -55° to 65°, and an outlet angle of the moving blades (25) being set within a range of -45° to 55°; the stator assembly comprises guide vanes (7) and multi-stage stationary blades (8), an inlet angle of the stationary blades (8) being set within a range of 40° to 50°, an outlet angle of the stationary blades (8) being set within a range of 10° to 30° and decreasing stage by stage, an inlet angle of the guide vanes (7) being set as 0°, and an outlet angle of the guide vanes (7) being set within a range of 30° to 40°; and a spacing between rows of the moving blades (25) and rows of the stationary blades (8) is set to be reduced stage by stage and is set within a range of 9-35 mm. The housing assembly comprises a compressor housing (1), wherein an air inlet and an air outlet are formed in the compressor housing (1) in a radial direction. Further provided is a high-temperature heat pump energy storage system, comprising a compressor-expander unit for a high-temperature heat pump. The compressor-expander unit for a high-temperature heat pump can effectively adapt to working conditions with a high air inlet temperature and temperature fluctuations, so that the efficiency and service life of the compressor can be improved.

Description

Compression expansion unit for high-temperature heat pump and high-temperature heat pump energy storage system Technical Field

[0001] The present invention relates to the field of energy technology, and in particular to a compression expansion unit for a high-temperature heat pump and a high-temperature heat pump energy storage system. Background Art

[0002] With the rapid development and expansion of new energy sources, the demand for energy storage continues to grow. Compressors and expanders are core components of heat pump energy storage technology. Temperature is the most critical parameter for compressors. How to cost-effectively and efficiently increase the compressor outlet temperature is a key issue in the current application of compressors in heat pump energy storage.

[0003] Conventional compressors operate at relatively low and stable inlet temperatures. However, when operating under high temperatures, bearing components, lubricants, and other components cannot withstand these conditions and function properly. In such cases, expensive materials are typically used to meet the performance requirements under high-temperature operating conditions, increasing costs. Furthermore, high and fluctuating inlet temperatures can significantly impact compressor stability and efficiency. Therefore, a compressor design that can withstand high-temperature conditions is urgently needed to ensure safe and efficient operation.

[0004] Summary of the Invention

[0005] In response to the deficiencies in the prior art, the present invention provides a compression-expansion unit for a high-temperature heat pump and a high-temperature heat pump energy storage system, which solves the problems in the prior art that when the intake temperature is high and there are temperature fluctuations, the current compressor cannot effectively adapt to such working conditions, resulting in reduced compressor efficiency and shortened life.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions:

[0007] A compression expansion unit for a high-temperature heat pump comprises a multi-stage axial flow compressor and an axial flow expander, wherein the rotating shafts of the compressor and the expander run coaxially;

[0008] Wherein, the compressor comprises a rotor assembly, a stator assembly and a housing assembly;

[0009] A rotor assembly is used to impart kinetic energy to the gas and drive the gas to move axially within the compressor; the rotor assembly includes multiple stages of moving blades, the inlet angle of the moving blades is set to -55 to 65 degrees, and the outlet angle of the moving blades is set to -45 to -55 degrees;

[0010] A stator assembly is used to convert the kinetic energy of the gas into pressure energy and adjust the gas flow direction; the stator assembly includes guide vanes and multi-stage stationary vanes, the inlet angle of the stationary vanes is set to 40-50 degrees, and the outlet angle of the stationary vanes is set to 10-30 degrees and decreases step by step; the inlet angle of the guide vanes is set to 0 degrees, and the outlet angle of the guide vanes is set to 30-40 degrees;

[0011] The blade spacing between the moving blades and the stationary blades is set to a value of 9 to 35 mm, and the value is gradually reduced;

[0012] The outer shell assembly includes a compressor casing, on which a compressor air inlet and a compressor exhaust port are provided. The axial directions of the compressor air inlet and the compressor exhaust port are respectively N° and M° with the axis of the main shaft in the compressor, wherein 0<N<180, 0<M<180.

[0013] In this application, the compressor application scenarios have the following characteristics: This application targets operating conditions with inlet temperatures between 100°C and 200°C, with a large temperature difference and high and fluctuating inlet temperatures. Furthermore, the outlet temperature in this application is high, exceeding 400°C, placing requirements on both structural design and material selection. Due to the wide operating temperature range, excessively large pitch between the moving and stationary blades can reduce the compressor's performance while other parameters remain unchanged, making it impossible to meet the outlet temperature requirement of 400°C or higher. Alternatively, excessively large pitch between the moving and stationary blades can increase other parameters, such as the number of stages and blade parameters, leading to machining failures or a sharp increase in machining and design costs, making it uneconomical and unsuitable for market demand. When the pitch between the moving and stationary blades is too small, while other parameters remain unchanged, the compressor's performance improves and its economic efficiency improves. However, due to the high compressor temperature, the blades undergo axial thermal expansion in the high-temperature environment. Consequently, after the compressor has been running for a period of time, adjacent blades may interfere with each other, shortening the compressor's service life or even causing the compressor to fail to operate normally. Therefore, the data selection for the moving blades, stationary blades, and guide vanes in the present invention ensures both operational safety and performance and operating range. The radially arranged air inlet can ensure that gases with poor uniformity can be mixed to a certain extent when entering the flow channel through the air inlet, thereby achieving better uniformity, and to a certain extent solving the problem of wide operating conditions. The radially arranged air inlet, combined with the setting of the stationary blades, guide vanes, moving blades, and row spacing, can enable the compressor to meet high-temperature operating conditions with an intake temperature of 100 to 200°C, while further meeting the requirements of high compressor efficiency, long life, and low cost.

[0014] Furthermore, the value of the rotor blade outlet angle of the compressor first increases step by step and then decreases step by step along the direction of increasing gas temperature; and / or the value of the primary rotor blade outlet angle of the compressor is greater than the value of the final rotor blade outlet angle of the compressor.

[0015] Furthermore, the value of the blade inlet angle of the compressor first increases step by step and then decreases step by step along the direction of increasing gas temperature; and / or the value of the primary blade inlet angle of the compressor is greater than the value of the final blade inlet angle of the compressor.

[0016] Furthermore, the value of the stator blade outlet angle of the compressor decreases step by step in the direction of increasing gas temperature.

[0017] Furthermore, the inlet angle values ​​of the stator blades of each stage of the compressor are dispersedly set within the range of 40 to 50 degrees.

[0018] Furthermore, the stator blades of each stage are all curved.

[0019] Furthermore, the stator blade bending circumferential stacking Rtheta off 50% span is set to -20 to -26.

[0020] The use of bending characteristics can effectively control the low-speed flow in the corner area of ​​the stator blades. During the design process of this unit, a suitable bending law was selected based on the flow characteristics of each stage of stator blades to maximize the control of the corner area flow of each stage of stator blades and improve the operating range of the compressor to the greatest extent.

[0021] Further, the circumferential stacking Rtheta off 50% span of the first-stage stator blades is smaller than the circumferential stacking Rtheta off 50% span parameter of the last-stage stator blades; and / or, the circumferential stacking Rtheta off 50% span of the first-stage stator blades is larger than the circumferential stacking Rtheta off 50% span parameter of the second-stage stator blades.

[0022] Furthermore, the aspect ratio of the moving blades is 1.2±0.1, and the aspect ratio of the stationary blades is 1.66-1.28.

[0023] A wide chord length design is adopted to further reduce the blade load and weaken the possibility and intensity of boundary layer separation on the blade surface, thereby improving compressor efficiency and widening the operating range.

[0024] Furthermore, the compressor load coefficient distribution range is 0.17 to 0.28.

[0025] Furthermore, the load coefficient of the compressor first increases step by step and then decreases step by step from the primary stage to the final stage of the compressor; and / or, the load coefficient of the primary stage of the compressor is smaller than the load coefficient of the final stage of the compressor.

[0026] Due to the high design temperature, the yield strength of the material decreases, and the allowable linear speed of the compressor shaft and blade tips decreases, so the selected value of the compressor load factor is reduced. The higher the load factor, the fewer the stages, and the greater the load on the single-stage compressor, but it is more difficult to improve efficiency and expand the operating range.

[0027] Furthermore, the reaction degree distribution range of the compressor from the second stage is 0.58 to 0.75.

[0028] Ensure proper load distribution between the rotor and stator blades, maximizing efficiency while maintaining the operating range. Since the first stage contains IGVs, the values ​​are not meaningful, so start from the second stage.

[0029] Furthermore, the reaction degree value increases step by step from the second stage of the compressor to the last stage of the compressor.

[0030] Furthermore, the stage pressure ratio of the compressor is 1.02 to 1.09.

[0031] Furthermore, the stage pressure ratio value of the compressor first increases step by step and then decreases step by step from the primary stage to the final stage of the compressor; and / or, the primary stage pressure ratio value is smaller than the final stage pressure ratio value.

[0032] The pressure ratio of the first few stages is slightly lower to reduce the Mach number as much as possible, thereby widening the operating range; the pressure ratio of the subsequent stages is also gradually reduced, thereby weakening the disadvantage of the boundary layer thickening stage by stage, reducing the possibility of separation in the subsequent stages, and improving efficiency.

[0033] Furthermore, the directions of the compressor air inlet and the compressor exhaust port are arranged along the radial direction of the main shaft, that is, the axial directions of the compressor air inlet and the compressor exhaust port are both 90° to the axis of the main shaft in the compressor.

[0034] Furthermore, the rotor assembly also includes a wheel shaft, the main shaft in the compressor is composed of multiple wheel shafts connected end to end, and the moving blades are fixedly connected to the circumferential surface of the wheel shaft; a pull rod is passed through the multiple wheel shafts, one end of the pull rod is threadedly connected to a nut, and the multiple wheel shafts are locked by the nut.

[0035] Furthermore, each stage of the wheel shaft is provided with at least one stage of moving blades; wherein, the number of moving blades installed on the lower stage wheel shaft along the gas movement direction is not less than the number of moving blades installed on the upper stage wheel shaft.

[0036] Furthermore, two adjacent end surfaces of the adjacent wheel axles are respectively provided with connecting parts, and the adjacent wheel axles are connected through the connecting parts.

[0037] Furthermore, the connecting portion is an end tooth provided on the end face of the wheel axle, and the end teeth on the two end faces adjacent to the wheel axles are meshed.

[0038] Furthermore, the stator assembly also includes an inner cylinder, the inner surface of which is provided with an annular groove with an I-shaped cross-section; a guide vane is fixedly connected in the annular groove closest to the compressor air inlet, and stationary blades are fixedly connected in the remaining annular grooves, and the stationary blades are spaced apart from the moving blades.

[0039] Furthermore, the guide vane includes a guide blade and a guide vane root, and the guide vane root is fixedly arranged in the annular groove along its circumference; the length direction of the guide vane root is the same as the axial direction of the inner cylinder.

[0040] Furthermore, the stator blades include stator blades and stator blade roots, and the stator blade roots are fixedly arranged in the annular groove along the circumference thereof; the length direction of the stator blade roots is arranged to be inclined relative to the axial direction of the inner cylinder; the circumferential spacing between stator blades of the same level is the same, and the circumferential spacing between stator blades of different levels gradually decreases along the airflow direction.

[0041] Furthermore, a compressor channel is formed between the inner cylinder and the wheel shaft, and the compressor channel is set to any one of equal outer diameter, equal inner diameter and equal median diameter.

[0042] Furthermore, a thrust bearing and a radial bearing are provided on the main shaft inside the compressor, an air intake cavity is provided between the compressor air inlet and the compressor channel, and an exhaust cavity is provided between the compressor exhaust port and the compressor channel. The space where the thrust bearing is located and the air intake cavity, and the space where the radial bearing is located and the exhaust cavity are isolated from each other by shaft end seals, respectively. The thrust bearing and the radial bearing are located outside the air flow channel formed by the air intake cavity, the compressor channel and the exhaust cavity.

[0043] Furthermore, the shaft end seal is configured as a labyrinth seal structure, and cooling sealing gas is injected into the shaft end seal, wherein the cooling sealing gas is air.

[0044] Furthermore, it also includes an expander casing, and the compressor casing and the expander casing are connected by bolts.

[0045] Furthermore, it also includes a compressor base, on which are provided several groups of support assemblies, including one group of fixed support assemblies and two groups of swing support assemblies; the fixed support assembly is located in the middle of the compressor base and is fixedly connected to the compressor casing, and the two groups of swing support assemblies are respectively located on both sides of the compressor base and are respectively movably connected to the compressor casing.

[0046] The present invention also provides a high-temperature heat pump energy storage system, which includes a compression-expansion unit for a high-temperature heat pump, a heat source circulation supply system, and an energy storage device.

[0047] The present invention has the following beneficial effects:

[0048] 1. The present invention is aimed at the high-temperature working conditions of the compressor. Since the intake temperature of the compressor is relatively high, some bearing parts and lubricating oil cannot work under high-temperature working conditions. Therefore, a radial air intake method is adopted to design the bearings and other parts outside the air flow channel formed by the intake cavity, the compressor channel and the exhaust cavity, thereby isolating the bearing area from the high-temperature intake area, so that the bearings can avoid high-temperature working conditions. At the same time, cooling sealing gas is added to the shaft end seal to isolate the high-temperature gas from entering the bearing area while also cooling the shaft end. At this time, the use of conventional bearing materials can meet the safe and reliable operation of the compressor under high-temperature working conditions.

[0049] 2. By rationally arranging the intake and exhaust methods, optimizing the aerodynamic design of the guide vanes, stator blades and moving blades, selecting appropriate inlet and outlet angles, and optimizing the blade row spacing, the working efficiency of the compressor is improved, the stable operation of the compressor is maintained, and the safe and efficient operation of the compressor under high temperature conditions is further ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] FIG1 is a schematic diagram of a high-temperature heat pump energy storage system according to the present invention;

[0051] FIG2 is a schematic structural diagram of a compression-expansion unit in Example 1 of the present invention;

[0052] FIG3 is a cross-sectional view of the compressor in Example 1 of the present invention;

[0053] FIG4 is a schematic diagram showing the positional relationship of the support components in Example 2 of the present invention;

[0054] FIG5 is a schematic structural diagram of the wheel axle in Example 1 of the present invention;

[0055] FIG6 is a schematic structural diagram of the guide vane in Example 1 of the present invention;

[0056] FIG7 is a schematic structural diagram of the inner cylinder in Example 1 of the present invention;

[0057] FIG8 is a schematic diagram of the circumferential stacking Rtheta off 50% span of the stator blade in Example 1 of the present invention;

[0058] FIG9 is a schematic diagram of blade row spacing in Example 1 of the present invention;

[0059] FIG10 is a schematic diagram of the reaction degree distribution interval of the compressor in Example 1 of the present invention;

[0060] FIG11 is a schematic diagram of the load coefficient distribution interval of the compressor in Example 1 of the present invention;

[0061] FIG12 is a schematic diagram of the stage pressure ratio distribution range of the compressor in Example 1 of the present invention;

[0062] FIG13 is a schematic diagram of the structure of the stationary blade locking group in Example 3 of the present invention.

[0063] In the above drawings: 1. Compressor casing; 2. Compressor base; 3. Compressor air inlet; 4. Compressor exhaust port; 5. Inner cylinder; 6. Ring groove; 7. Guide vane; 8. Stationary vane; 9. Axle; 10. Pull rod; 11. Compressor channel; 12. Baffle; 13. Thrust bearing; 14. Radial bearing; 15. Inlet cavity; 16. Exhaust cavity; 17. First sealing gas duct; 18. Second sealing gas duct; 19. End teeth; 20. Fixed support assembly; 21. Swing support assembly; 22. Center dividing surface of cylinder body; 23. Stationary vane of center dividing surface; 24. Cutting angle plane; 25. Moving vane. DETAILED DESCRIPTION

[0064] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0065] Example 1

[0066] A compression-expansion unit for a high-temperature heat pump comprises a multi-stage axial-flow compressor and an axial-flow expander. The compressor is an air compressor, compressing air from high-temperature, atmospheric pressure to approximately 0.6 MPa and 400°C. It features high flow, a high pressure ratio, high temperatures, frequent adjustment to varying operating conditions, and frequent starts and stops. The expander is an air expander, used to expand air from normal-temperature, high-pressure air to low-temperature, atmospheric pressure air to generate cooling capacity. It is coaxially connected to the air compressor to offset some of the compressor's power consumption and features high flow, a large expansion ratio, low temperatures, frequent adjustment to varying operating conditions, and frequent starts and stops.

[0067] As shown in Figures 2 and 3, the compressor includes a rotor assembly, a stator assembly, and a housing assembly. The housing assembly includes a compressor casing 1, which is provided with a compressor air inlet 3 and a compressor exhaust port 4. The axial directions of the compressor air inlet 3 and the compressor exhaust port 4 are respectively N° and M° with the axis of the main shaft in the compressor, where 0 < N < 180 and 0 < M < 180. In this embodiment, the air inlet and exhaust ports are preferably arranged along the radial direction of the main shaft, that is, the axial directions of the compressor air inlet 3 and the compressor exhaust port 4 are both 90° with the axis of the main shaft in the compressor.

[0068] The stator assembly converts the kinetic energy of the gas into pressure energy and adjusts the gas flow. As shown in Figures 3 and 7, the stator assembly includes an inner cylinder 5, located within the outer shell assembly. The inner cylinder 5 is formed by combining an upper and lower cylinder halves. Multiple annular grooves 6 with I-shaped cross-sections are defined on the inner surface of the inner cylinder 5. Guide vanes 7 are fixedly attached to the annular grooves 6 closest to the compressor inlet 3, while multiple stages of stator vanes 8 are fixedly attached to the remaining annular grooves 6.

[0069] Among them, the guide vane 7 includes a guide blade and a guide vane root. The guide vane root is fixedly arranged along the circumference of the annular groove 6, and the length direction of the guide vane root is the same as the axial direction of the inner cylinder 5. The guide vane is a three-dimensional twisted blade, which provides pre-rotation for the next stage blade by changing the flow state of the gas. The inlet angle of the guide vane 7 is set to 0°, and the outlet angle of the guide vane 7 is set to 35°. As shown in Figure 6, the stator 8 includes a stator blade and a stator root. The stator blade is a three-dimensional twisted blade, that is, it is curved. The use of a three-dimensional twisted blade for the stator 8 can effectively control the low-speed flow in the corner area of ​​the stator 8. Based on the flow characteristics of each stage of the stator 8, the appropriate bending law is selected to maximize the control of the corner area flow of each stage of the stator 8, thereby improving the working range of the compressor to the greatest extent. The stator root is fixedly arranged along the circumference of the annular groove 6; the length direction of the stator root is relatively inclined to the axial direction of the inner cylinder 5. The inlet angle of the stator blades 8 is set to 40-50°, and the inlet angle values ​​of the stator blades 8 at each stage are dispersed within the range of 40-50°. The outlet angle of the stator blades 8 is set to 10-30°, and the outlet angle values ​​of the stator blades 8 decrease step by step in the direction of increasing gas temperature. The axial spacing between the stator blades 8 of the same stage is the same, and the circumferential spacing between the stator blades 8 of different stages gradually decreases along the direction of airflow. The gas decelerates, increases pressure, and heats within the flow path of the stator blades 8, converting velocity energy into pressure energy and heat energy. The aspect ratio of the stator blades 8 at each stage is within the range of 1.28-1.66. As shown in Figure 8, the curved circumferential stacking Rtheta off 50% span of the stator blades 8 is set to between -20 and -26. The circumferential stacking Rtheta off 50% span of the first-stage stationary blades 8 is smaller than the circumferential stacking Rtheta off 50% span parameter of the last-stage stationary blades 8 ; the circumferential stacking Rtheta off 50% span parameter of the first-stage stationary blades 8 is larger than the circumferential stacking Rtheta off 50% span parameter of the second-stage stationary blades 8 .

[0070] The rotor assembly is used to impart kinetic energy to the gas compressor channel 11 and drive the gas to move along its axial direction inside the compressor. The rotor assembly is located in the internal space of the inner cylinder 5 and includes multiple axles 9. The multiple axles 9 are connected end to end, and the same pull rod 10 is passed through the multiple axles 9 to form the main shaft of the compressor, which is driven to rotate by a motor. The compressor channel 11 is formed between the inner cylinder 5 and the axle 9 and can be set to any one of equal outer diameter, equal inner diameter and equal median diameter. Among them, the equal outer diameter is set to the inner diameter of the inner cylinder 5 remains unchanged along the direction of the airflow, and the equal inner diameter is set to the outer diameter of the axle 9 remains unchanged along the direction of the airflow. The compressor channel 11 in this embodiment is set to an equal median diameter structure, that is, the inner diameter of the inner cylinder 5 gradually decreases along the direction of the airflow, and the outer diameter of the axle 9 gradually increases along the direction of the airflow.

[0071] Rotating blades 25 are fixedly mounted on the circumference of the multiple axles 9 along their circumference, forming a multi-stage rotating blade structure. The number of rotating blades mounted on the lower axle along the direction of gas flow within the compressor is no less than the number of rotating blades mounted on the upper axle. The blades following the guide vanes 7 are rotating blades 25, and the blades following the rotating blades 25 are stationary blades 8. The rotating blades 25 are three-dimensionally twisted blades, with an inlet angle of -55 to 65 degrees and an outlet angle of -45 to -55 degrees. In this multi-stage rotating blade structure, the outlet angles of the compressor's rotating blades 25 gradually increase and then decrease as the gas temperature rises, and the outlet angles of the first-stage rotating blades 25 are greater than those of the last-stage rotating blades 25. The inlet angles of the compressor's rotating blades 25 gradually increase and then decrease as the gas temperature rises, and the inlet angles of the first-stage rotating blades 25 are greater than those of the last-stage rotating blades 25. The aspect ratio of rotor blade 25 is set at 1.2, employing a wide chord design to further reduce blade loads and mitigate the likelihood and intensity of boundary layer separation, thereby improving compressor efficiency and widening the operating range. As shown in Figure 11, the compressor load factor distribution ranges from 0.17 to 0.28. The load factor increases and then decreases from the primary stage to the final stage, with the primary stage load factor being smaller than the final stage load factor. As shown in Figure 10, the compressor reaction degree distribution ranges from 0.58 to 0.75, with the reaction degree increasing from the second stage to the final stage. As shown in Figure 12, the compressor stage pressure ratio ranges from 1.02 to 1.09. The stage pressure ratio increases and then decreases from the primary stage to the final stage, with the primary stage pressure ratio being smaller than the final stage pressure ratio.

[0072] The moving blades 25 and the stationary blades 8 are spaced apart. As shown in FIG9 , the blade row spacing of the moving blades 25 and the stationary blades 8 is set at 9 to 35 mm and gradually decreases along the airflow direction. Under high-temperature working conditions, the thermal expansion of the moving blades 25 and the stationary blades 8 is greater than that of conventional industrial compressors. During the design process, the distance between the blade rows must be set based on the accurate expansion difference to ensure that the moving blades 25 and the stationary blades 8 do not collide with each other under any working conditions of the unit. A large spacing between the blade rows will affect the operating range of the compressor. Therefore, the design of this blade row spacing ensures both operational safety and performance and operating range. A balancing disk is set behind the last-stage blades, and a balancing disk seal is configured to further balance the axial thrust and reduce gas leakage. In this embodiment, the aerodynamic design features are as follows: the consistency of the moving blades 25 is about 1, the stationary blades 8 adopt a large consistency and high aspect ratio design, the stage pressure ratio distribution has the front stage pressure ratio gradually increasing, the middle stage pressure ratio is the highest at 1.16, and the final stage pressure ratio gradually decreasing, and the reaction degree increases step by step, so that the airflow in the compressor flow channel is more stable, the risk of flow field deterioration caused by air flow loss is reduced, which is beneficial to improving the efficiency of the compressor and increasing the stable operating range of the compressor.

[0073] A baffle 12 is provided in the casing opposite the air inlet. High-temperature gas enters the compressor through the radial air inlet, impacts the baffle 12, and then flows back to the inlet of the inner cylinder 5. At this time, due to the high-speed rotation of the rotor blades 25, the high-temperature gas is sucked into the guide vanes 7. After passing through the guide vanes, it forms a pre-swirl. Thereafter, it is accelerated by the rotor blades 25, pressurized and heated by the stator blades 8, and flows to the exhaust port as high-temperature and high-pressure gas.

[0074] The main shaft is equipped with a thrust bearing 13 and a radial bearing 14. Specifically, the thrust bearing 13 is located at the low-pressure end of the main shaft to balance some of the thrust on the high-pressure side, and the radial bearing 14 is located at the high-pressure end to meet the requirements of high-speed operation of the main shaft. An intake cavity 15 is located between the compressor inlet 3 and the compressor passage 11, and an exhaust cavity 16 is located between the compressor exhaust 4 and the compressor passage 11. The space between the thrust bearing 13 and the intake cavity 15, and the space between the radial bearing 14 and the exhaust cavity 16 are isolated from each other by shaft end seals. The thrust bearing 13 and the radial bearing 14 are located outside the airflow channel formed by the intake cavity 15, the compressor passage 11, and the exhaust cavity 16. The shaft end seal is set as a labyrinth seal structure, and a first sealing air duct 17 and a second sealing air duct 18 are respectively provided on both sides of the compressor casing 1. The first sealing air duct 17 and the second sealing air duct 18 are respectively connected to the two shaft end seals. The shaft end seals are injected with cooling sealing air through the first sealing air duct 17 and the second sealing air duct 18 to further isolate the high temperature inside the compressor and reduce the leakage of high temperature gas to the other side of the thrust bearing 13 and the radial bearing 14.

[0075] The high-temperature heat pump compression-expansion unit in this embodiment also includes an expander housing. The compressor housing 1 and the expander housing are connected by bolts, and the two are internally connected. The expander includes a rotating shaft. A common tie rod 10 passes through the compressor's axle 9 and the expander's rotating shaft, allowing the compressor and expander to share a common main shaft. Nuts are threaded onto the tie rod 10, and the multiple axles 9 are locked together by the nuts. Connections are provided between adjacent axles 9 and between the axles 9 and the expander's rotating shaft, and transmission is achieved through these connections. As shown in Figure 5, in this embodiment, the connection is provided as end teeth 19 located on the end faces of the axles 9 and the rotating shaft, with adjacent end teeth 19 meshing with each other. A tapered shaft end is provided at one end of the main shaft to ensure safe and stable torque transmission to the compressor. This application simplifies the structural design of the compression-expansion unit and can effectively reduce unit efficiency losses. The expander housing is directly connected to the compressor housing 1 by bolts, eliminating the need for a separate support structure for the expander, allowing the expander to move axially with the thermal expansion of the compressor.

[0076] As shown in Figure 1, this embodiment also provides a high-temperature heat pump energy storage system, including a heat source circulation supply system, an energy storage device, and the above-mentioned high-temperature heat pump compression expansion unit, and also includes a steam circulation system. Among them, the heat source circulation supply system is used to provide hot air, including using an electric heater to heat the water in the cold water tank into hot water, and transporting it in a thermal simulation circulation pipeline through a circulating water pump, and generating hot air after absorbing heat in an air heat absorption cooler; the high-temperature heat pump cycle of the high-temperature heat pump compression expansion unit is the main system cycle; the energy storage device is a pressurized solid energy storage device, which serves as an efficient and low-cost energy storage device that takes into account both heat exchange and heat storage functions; the steam circulation system is used to absorb the heat produced in the high-temperature heat pump and stored in the solid energy storage device, and generate steam.

[0077] Example 2

[0078] As shown in FIG4 , this embodiment further includes a compressor base 2 . Since the compressor casing 1 and the expander casing are connected as one through bolts, the expander can perform axial displacement as the compressor expands thermally.

[0079] The compressor base 2 is equipped with three support assemblies: a fixed support assembly 20 and two swing support assemblies 21. The fixed support assembly 20 is located in the center of the compressor base 2, while the swing support assemblies 21 are located on either side of the fixed support assembly 20, also on either side of the compressor base 2. Each support assembly has two support points, meaning the compressor in this embodiment utilizes a six-point support system. The fixed support assembly 20 is fixed at two locations in the center of the compressor base 2. The fixed support assembly 20 includes two first fixing blocks fixed to the center of the compressor base 2, arranged along the width of the compressor and bolted to the center of the compressor casing 1. The swing support assembly 21 includes a second fixing block and a swing lever. The second fixing blocks are located on either side of the two first fixing blocks on the compressor base 2, and the swing lever is fixed to the second fixing block. Four sliding slots are provided on the bottom of the compressor casing 1, and the other end of the swing lever slides into these slots. When the compressor casing 1 deforms, the swing lever slides to accommodate the deformation. After the compressor heats up, the presence of the swing support assembly 21 allows it to expand to both sides, thereby solving the deformation and stress problems caused by the thermal expansion of the compressor. By providing two sets of swing support assemblies 21, the movement deformation of a single set of swing support assemblies 21 can also be reduced, making the support structure safer and more stable. For conventional compressors with room temperature intake, the temperature of the primary corresponding section is relatively low, and the thermal expansion is relatively small, so it will not accumulate in large quantities along the axial direction toward the swing point. However, the intake air of the compressor of this invention is high temperature, and the primary corresponding section will experience a large amount of thermal expansion during the operation of the compressor section for a period of time. If the end fixed support solution in the prior art is adopted, the thermal expansion will accumulate along the axial direction toward the swing support point. Due to the large axial length, material factors, etc., the compressor casing, base, etc. will be deformed and damaged, and the compressor will not meet the use requirements.

[0080] Example 3

[0081] As shown in Figure 13, in this embodiment, the stator assembly also includes a vane locking assembly. This assembly comprises vanes 8, an I-shaped annular groove 6 formed on the inner surface of the inner cylinder 5, a center-split vane 23, and locking screws. The vane roots of the vanes 8 are fixed within the annular groove 6, and the circumferential spacing between adjacent vanes 8 is determined by the width of the vane roots.

[0082] The inner cylinder 5 is formed by the combination of an upper and lower cylinder halves, with a center plane 22 defining the contact point between the upper and lower cylinder halves. Center plane stator blades 23 are positioned within the annular groove 6 at center plane 22. The blade roots of these vanes are angled, with angled surfaces 24 parallel to center plane 22 defined at the base. This prevents interference between the blade roots and the inner cylinder 5 during assembly due to the angle of the vanes 23. Locking screws are also installed on the angled surfaces 24 to secure the vanes 23 to the inner cylinder 5, ensuring that the vanes in the upper cylinder do not slip out of the annular groove 6 during assembly of the inner cylinder 5.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A compression-expansion unit for a high-temperature heat pump, characterized in that, It includes a multi-stage axial compressor and an axial expander, and the rotating shafts of the compressor and the expander operate coaxially. Among them, the compressor includes a rotor assembly, a stator assembly and a housing assembly. The rotor assembly is used to impart kinetic energy to the gas and drive the gas to move axially inside the compressor; the rotor assembly includes multiple stages of moving blades (25), the inlet angle of the moving blades (25) is set to -55 to 65°, and the outlet angle of the moving blades (25) is set to -45 to -55°. The stator assembly is used to convert the kinetic energy of the gas into pressure energy and adjust the gas flow direction; the stator assembly includes guide vanes (7) and multiple stages of stationary blades (8), the inlet angle of the stationary blades (8) is set to 40 to 50°, the outlet angle of the stationary blades (8) is set to 10 to 30° and decreases gradually stage by stage; the inlet angle of the guide vanes (7) is set to 0°, and the outlet angle of the guide vanes (7) is set to 30 - 40°; the blade row spacing value of the moving blades (25) and the stationary blades (8) is set to 9 to 35 mm, and the value decreases gradually stage by stage. The housing assembly includes a compressor housing (1), a compressor inlet (3) and a compressor outlet (4) are provided on the compressor housing (1), and the axial directions of the compressor inlet (3) and the compressor outlet (4) are at N° and M° respectively with respect to the axis where the main shaft is located inside the compressor, where 0 < N < 180 and 0 < M < 180.

2. The compression-expansion unit for a high-temperature heat pump according to claim 1, characterized in that The outlet angle value of the moving blades (25) of the compressor first increases gradually stage by stage and then decreases gradually stage by stage along the direction of increasing gas temperature. And / or the outlet angle value of the primary moving blades (25) of the compressor is greater than the outlet angle value of the last-stage moving blades (25) of the compressor.

3. A compression-expansion unit for a high-temperature heat pump according to claim 1, characterized in that, The inlet angle value of the moving blades (25) of the compressor first increases gradually stage by stage and then decreases gradually stage by stage along the direction of increasing gas temperature. And / or the inlet angle value of the primary moving blades (25) of the compressor is greater than the inlet angle value of the last-stage moving blades (25) of the compressor.

4. The compression-expansion unit for a high-temperature heat pump according to claim 1, characterized in that, The outlet angle value of the stationary blades (8) of the compressor decreases gradually stage by stage along the direction of increasing gas temperature.

5. A compression-expansion unit for a high-temperature heat pump according to claim 1, characterized in that, The inlet angle values of the stationary blades (8) of each stage of the compressor are dispersedly set within the range of 40 to 50°.

6. The compression-expansion unit for a high-temperature heat pump according to claim 1, characterized in that, Each stage of the stationary blades (8) is curved.

7. A compression-expansion unit for a high-temperature heat pump according to claim 6, characterized in that, The circumferential stacking Rtheta off 50% span of the stationary blades (8) is set to -20 to -26.

8. A compression-expansion unit for a high-temperature heat pump according to claim 7, characterized in that, The circumferential stacking Rtheta off 50% span of the first-stage stationary blades (8) is less than the circumferential stacking Rtheta off 50% span parameter of the last-stage stationary blades (8); and / or, the circumferential stacking Rtheta off 50% span of the first-stage stationary blades (8) is greater than the circumferential stacking Rtheta off 50% span parameter of the second-stage stationary blades (8).

9. A compression-expansion unit for a high-temperature heat pump according to claim 1, characterized in that, The aspect ratio of the moving blades (25) is 1.2 ± 0.1, and the aspect ratio of the stationary blades (8) is 1.28 to 1.

66.

10. A compression-expansion unit for a high-temperature heat pump according to claim 1, characterized in that, The distribution range of the compressor loading coefficient is between 0.17 and 0.

28.

11. A compression-expansion unit for a high-temperature heat pump according to claim 10, characterized in that, The loading coefficient of the compressor first increases gradually stage by stage and then decreases gradually stage by stage from the primary stage to the last stage of the compressor. And / or, the primary load coefficient of the compressor is less than the final stage load coefficient of the compressor.

12. A compression-expansion unit for a high-temperature heat pump according to claim 1, characterized in that, The reaction degree distribution range of the compressor from the second stage is 0.58 to 0.

75.

13. A compression-expansion unit for a high-temperature heat pump according to claim 12, characterized in that, The reaction degree value increases gradually from the second stage to the final stage of the compressor.

14. A compression-expansion unit for a high-temperature heat pump according to claim 1, characterized in that, The stage pressure ratio value of the compressor is 1.02 to 1.

09.

15. A compression-expansion unit for a high-temperature heat pump according to claim 14, characterized in that, The stage pressure ratio value of the compressor first increases gradually and then decreases gradually along the direction from the primary stage to the final stage of the compressor; And / or, the primary stage pressure ratio value is less than the final stage pressure ratio value.

16. A compression-expansion unit for a high-temperature heat pump according to claim 1, characterized in that, The directions of the compressor inlet (3) and the compressor outlet (4) are arranged along the radial direction of the main shaft, that is, the axis directions of the compressor inlet (3) and the compressor outlet (4) are both 90° to the axis where the main shaft is located inside the compressor.

17. A compression-expansion unit for a high-temperature heat pump according to claim 1, characterized in that, The rotor assembly further includes a wheel shaft (9), and the main shaft inside the compressor is composed of a plurality of wheel shafts (9) connected end to end. The moving blade (25) is fixedly connected to the circumferential surface of the wheel shaft (9); a pull rod (10) is arranged inside a plurality of the wheel shafts (9), and one end of the pull rod (10) is threadedly connected with a nut, and a plurality of the wheel shafts (9) are locked by the nut.

18. A compression-expansion unit for a high-temperature heat pump according to claim 17, characterized in that, At least one stage of moving blades is provided on each stage of the wheel shaft; Among them, the number of stages of the moving blades installed on the lower stage wheel shaft along the gas moving direction is not less than the number of stages of the moving blades installed on the upper stage wheel shaft.

19. A compression-expansion unit for a high-temperature heat pump according to claim 17, characterized in that, Connecting parts are respectively provided on two end faces of adjacent wheel shafts (9) close to each other, and adjacent wheel shafts (9) are connected through the connecting parts.

20. A compression-expansion unit for a high-temperature heat pump according to claim 19, characterized in that, The connecting part is an end tooth (19) provided on the end face of the wheel shaft (9), and the end teeth (19) on two end faces of adjacent wheel shafts (9) close to each other are engaged.

21. A compression-expansion unit for a high-temperature heat pump according to claim 17, characterized in that, The stator assembly further includes an inner cylinder (5), and an annular groove (6) with an I-shaped cross section is provided on the inner surface of the inner cylinder (5); a guide vane (7) is fixedly connected in the annular groove (6) closest to the compressor inlet (3), and stationary vanes (8) are fixedly connected in the remaining annular grooves (6), and the stationary vanes (8) and the moving blades (25) are arranged at intervals.

22. The compression-expansion unit for a high-temperature heat pump according to claim 21, wherein, The guide vane (7) includes a guide vane blade and a guide vane root, and the guide vane root is fixedly arranged along its circumferential direction in the annular groove (6); the length direction of the guide vane root is the same as the axis direction of the inner cylinder (5).

23. A compression-expansion unit for a high-temperature heat pump according to claim 21, characterized in that, The stationary vane (8) includes a stationary vane blade and a stationary vane root, and the stationary vane root is fixedly arranged along its circumferential direction in the annular groove (6); the length direction of the stationary vane root is arranged to be inclined relative to the axis direction of the inner cylinder (5); the circumferential spacing between the stationary vanes (8) of the same stage is the same, and the circumferential spacing between the stationary vanes (8) of different stages gradually decreases along the gas flow direction.

24. A compression-expansion unit for a high-temperature heat pump according to claim 21, characterized in that, A compressor passage (11) is formed between the inner cylinder (5) and the wheel shaft (9), and the compressor passage (11) is set to any one of equal outer diameter, equal inner diameter and equal mean diameter.

25. A compression-expansion unit for a high-temperature heat pump according to claim 24, characterized in that, A thrust bearing (13) and a radial bearing (14) are provided on the main shaft inside the compressor. An intake cavity (15) is provided between the compressor intake port (3) and the compressor passage (11), and an exhaust cavity (16) is provided between the compressor exhaust port (4) and the compressor passage (11). The space where the thrust bearing (13) is located and the intake cavity (15), and the space where the radial bearing (14) is located and the exhaust cavity (16) are isolated from each other by shaft end seals respectively. The thrust bearing (13) and the radial bearing (14) are located outside the air flow passage formed by the intake cavity (15), the compressor passage (11) and the exhaust cavity (16).

26. The compression-expansion unit for a high-temperature heat pump according to claim 25, characterized in that, The shaft end seal is set as a labyrinth seal structure, and cooling seal gas is injected into the shaft end seal. The cooling seal gas is air.

27. The compression-expansion unit for a high-temperature heat pump according to claim 1, characterized in that, It further includes an expander housing, and the compressor housing (1) and the expander housing are connected by bolts.

28. A compression-expansion unit for a high-temperature heat pump according to claim 27, characterized in that, It further includes a compressor base (2). A number of groups of support components are provided on the compressor base (2), including a group of fixed support components (20) and two groups of swing support components (21). The fixed support components (20) are located in the middle of the compressor base (2) and are fixedly connected to the compressor housing (1). The two groups of swing support components (21) are respectively located on both sides of the compressor base (2) and are respectively movably connected to the compressor housing (1).

29. A high-temperature heat pump energy storage system, characterized in that, It includes a compression-expansion unit for high-temperature heat pump according to any one of claims 1-28, and further includes a heat source circulation supply system and an energy storage device.

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