Cooling structure of high-temperature multi-shaft transmission device and design method thereof

Abstract

The invention relates to the technical field of advanced gas energy storage, in particular to a cooling structure of a high-temperature multi-shaft transmission device and a design method of the cooling structure. According to the technical scheme, an upper box body and a lower box body are spliced to form a cooling box body, a gear shaft penetrates through the cooling box body, a bearing is arranged between one end of the cooling box body and the gear shaft, and the other end of the cooling box body is connected with the gear shaft. A shaft seal is installed between the other end of the cooling box body and the gear shaft, a nozzle seat is radially and fixedly installed on an upper vertical plate of the upper box body in an inverted mode, an oil inlet pipe is fixedly installed above the nozzle seat, a nozzle is fixedly installed below the nozzle seat, the oil spraying area of the nozzle axially corresponds to the position of a cooling ring of the gear shaft, and the cooling ring is a step shaft section higher than the shaft diameter of the gear shaft. According to the scheme, heat conducted by the impeller of the high-temperature compressor can be effectively cooled, and the influence of high temperature on use safety of the gear shaft and the sliding bearing is eliminated.

Description

Technical Field

[0001] The present invention relates to the field of advanced gas energy storage technology, and in particular to a high-temperature multi-axis transmission device cooling structure and a design method thereof. Background Art

[0002] Advanced cycle power generation systems such as supercritical carbon dioxide (S-CO2) Brayton cycle power system have the advantages of high efficiency, high power density, fast start and stop, compact structure, low vibration and noise, wide adaptability of heat sources, etc., and can also effectively improve indicators such as endurance and maneuverability. It is mainly used in the field of nuclear power, and can also be combined with small nuclear reactors to meet the different power supply needs of remote water-scarce areas, important military facilities, overseas bases, and medium and far-sea islands and reefs. Among them, the multi-axis transmission device is the core component of the advanced cycle power generation unit, and the domestic research and development of this equipment is still in its infancy. The compressor impeller in the advanced cycle power generation unit is generally suspended on the integrated impeller-gear combined rotor system at the extended end of the transmission gear shaft, and the volute is integrated and installed on the outer casing of the transmission device, so this type of multi-axis transmission device is a compressor integrated transmission device.

[0003] The compressor drives the gas to rotate at high speed by the impeller, which generates centrifugal force. Due to the expansion pressure flow of the gas in the impeller, the flow rate and pressure of the gas after passing through the impeller are increased, and compressed gas is continuously produced. Because the gas medium in the advanced cycle power generation system is mostly high-temperature gas, and the temperature of the air will increase significantly after compression, the service environment temperature of the key parts of the impeller-gear combination rotor system of the multi-axis transmission device is too high and cannot work stably and normally, especially affecting the heat treatment performance of the gear alloy steel and the temperature of the bearing alloy after loading. When using gear alloy steel, it is required to be less than the minimum temperature of heat treatment tempering 200℃, the maximum temperature of high-temperature bearing alloy after loading is not higher than 130℃, and the maximum temperature of high-temperature gas medium can reach 500℃, so it is necessary to design a corresponding cooling structure to cool the shaft system of the multi-axis transmission device and evaluate the cooling effect.

[0004] In summary, the high-temperature gas after the air is compressed by the compressor impeller has the problem of causing the operating environment temperature of the key parts of the impeller-gear combination rotor system of the multi-axis transmission device to be too high and unable to work normally and stably. Summary of the invention

[0005] The purpose of the patent of this invention: The invention is to solve the problem that the high-temperature gas after the air is compressed by the compressor impeller causes the operating environment temperature of the key parts of the impeller-gear combination rotor system of the multi-axis transmission device to be too high and cannot work stably and normally. The present invention provides a high-temperature multi-axis transmission device cooling structure and its design method.

[0006] The object of the present invention is achieved as follows: A high-temperature multi-shaft transmission device cooling structure, which includes a gear shaft, a shaft seal, an upper box, a lower box, a nozzle, a nozzle seat, an oil inlet pipe and a bearing;

[0007] The upper box body and the lower box body are assembled to form a cooling box body. The interior of the cooling box body is arranged as a cavity to form an environment for oil injection cooling. The gear shaft passes through the cooling box body. A bearing is installed between one end of the cooling box body and the gear shaft. A shaft seal is installed between the other end of the cooling box body and the gear shaft. The shaft seal is fixedly embedded and installed between the upper box body and the lower box body. The gear shaft and the shaft seal clearance match. The other end of the gear shaft is connected to the compressor impeller. The nozzle seat is radially inverted and fixedly installed on the upper vertical plate of the upper box body. The oil inlet pipe is fixedly installed above the nozzle seat to provide cooling oil. The nozzle is fixedly installed below the nozzle seat to spray cooling oil. The nozzle spraying area axially corresponds to the cooling ring position of the gear shaft. The cooling ring is a stepped shaft section higher than the shaft diameter of the wheel axle.

[0008] Furthermore, the bearing is a sliding bearing, and the gear shaft is floatingly installed in the bearing, and the bearing realizes the radial support function of the gear shaft.

[0009] Still further, the bearing is a tilting pad plain bearing.

[0010] Further, the bearing is made of a high temperature bus alloy.

[0011] Furthermore, an oil return hole is provided on the lower side of the lower box body.

[0012] Furthermore, the shaft seal is a gas-liquid shaft seal.

[0013] Furthermore, the nozzle is a fan-shaped nozzle.

[0014] Furthermore, the other end of the gear shaft is connected to a compressor impeller.

[0015] Furthermore, the gear shaft is meshedly connected to the compressor impeller through end face teeth and is positioned and fixed by a central bolt connecting rod.

[0016] Furthermore, an end surface hollow groove with a depth of A is provided on the connecting end surface of the gear shaft and the compressor impeller.

[0017] A design method for a cooling structure of a high-temperature multi-axis transmission device comprises the following steps:

[0018] Step 1: Design the cooling mechanism infrastructure;

[0019] Step 2: Parametric modeling of the gear shaft, shaft seal, upper housing, lower housing, nozzle, nozzle seat, oil inlet pipe, and all cooling structures and lubricating oil of the bearing;

[0020] Step 3: Simulate and model the internal flow field of the key parts of the nozzle and gear shaft;

[0021] Step 4: Conduct gas-liquid two-phase flow field simulation, analyze the oil distribution of the cooling box at the key parts of the bearing at different times under different oil injection flow rates, obtain the change trend of the oil distribution of the gear shaft section at the key parts of the bearing over time, and simulate the convective heat transfer coefficient of the gear shaft section;

[0022] Step 5: Solve the temperature field distribution of the gear shaft section at the key part of the bearing, and confirm whether the temperature of each gear shaft section meets the use requirements. If it meets the use requirements, proceed to step 6, and if it does not meet the use requirements, proceed to step 2;

[0023] Step 6: Confirm the nozzle flow, gear shaft section size and cooling box space data;

[0024] Step 7: Finally complete the cooling structure design and confirm it.

[0025] Beneficial effects:

[0026] The present invention provides a cooling structure for a high-temperature multi-axis transmission device. When the maximum temperature of the high-temperature gas medium can reach 500°C, the cooling structure can effectively cool the heat conducted by the impeller of the high-temperature compressor, eliminate the influence of high temperature on the safe use of gear shafts and sliding bearings, and meet the requirements that the gear alloy steel should be used at a minimum temperature of 200°C less than the minimum temperature of heat treatment tempering, and the high-temperature bearing alloy should not have a maximum load-bearing temperature higher than 130°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of a cooling structure of a high-temperature multi-axis transmission device of the present invention. Figure 1 ;

[0028] Figure 2 This is a schematic diagram of a cooling structure of a high-temperature multi-axis transmission device of the present invention. Figure 2 ;

[0029] Figure 3 It is a schematic diagram of the application of a high-temperature multi-axis transmission device cooling structure of the present invention in a certain type of high-temperature multi-axis transmission device;

[0030] Figure 4 The present invention discloses a flow chart of cooling structure design of a high-temperature multi-axis transmission device. DETAILED DESCRIPTION

[0031] Specific implementation method 1: A high-temperature multi-axis transmission device cooling structure, which includes a gear shaft 2, a shaft seal 3, an upper box 4, a lower box 5, a nozzle 6, a nozzle seat 7, an oil inlet pipe 8 and a bearing 9;

[0032] The upper box body 4 and the lower box body 5 are assembled to form a cooling box body, and the interior of the cooling box body is arranged as a cavity to form an environment for oil injection cooling. The gear shaft 2 passes through the cooling box body, and a bearing 9 is installed between one end of the cooling box body and the gear shaft 2, and a shaft seal 3 is installed between the other end of the cooling box body and the gear shaft 2. The shaft seal 3 is fixedly embedded and installed between the upper box body 4 and the lower box body 5, and the gear shaft 2 and the shaft seal 3 are clearance-matched. The other end of the gear shaft 2 is connected to the compressor impeller 1, and the nozzle seat 7 is radially inverted and fixedly installed on the upper vertical plate of the upper box body 4. The oil inlet pipe 8 is fixedly installed above the nozzle seat 7 to provide cooling oil, and the nozzle 6 is fixedly installed below the nozzle seat 7 to spray cooling oil. The oil spraying area of ​​the nozzle 6 corresponds axially to the cooling ring position of the gear shaft 2, and the cooling ring is a stepped shaft section higher than the shaft diameter of the wheel shaft 2.

[0033] In this embodiment: the shaft seal not only blocks the oil and gas inside the box from escaping, but also blocks the high-temperature and high-pressure gas on the impeller side from entering the box;

[0034] The cavities in the shaft seal, upper housing, lower housing and sliding bearing are designed to form an oil-spray cooling environment;

[0035] The bearing realizes the radial support function of the gear shaft;

[0036] The temperature generated by the high-temperature gas and the high-speed rotation of the impeller is transmitted from the impeller to the gear shaft. Due to the gas-liquid sealing of the shaft seal, the temperature field is divided into different parts inside and outside the box. The temperature is transmitted from the end of the gear shaft to the box along the axial direction. The temperature transmitted to the gear shaft is lower than the minimum temperature of 200°C required for heat treatment tempering when the gear alloy steel is used. The cooling oil enters the nozzle seat from the oil inlet pipe and is sprayed out by the nozzle. The fan-shaped cooling oil sprayed is evenly sprayed on the cooling ring of the gear shaft. The cooling ring is a stepped shaft section higher than the shaft diameter, which not only increases the cooling contact area of ​​the outer edge of the shaft diameter, but also increases the annular cooling and heat dissipation surface on both sides of the stepped shaft. At this time, the temperature of the shaft section near the sliding bearing on the gear shaft has reached the cooling effect, and combined with the temperature rise generated by the bearing operation, the temperature is lower than the maximum load-bearing temperature of the high-temperature bearing alloy, which is not higher than 130°C.

[0037] Specific implementation method 2: A high-temperature multi-axis transmission device cooling structure, the bearing 9 is a sliding bearing, the gear shaft 2 is floatingly installed in the bearing 9, and the bearing 9 realizes the radial support function of the gear shaft 2.

[0038] In this embodiment: the bearing realizes the radial support function of the gear shaft

[0039] Other implementations are the same as the first specific implementation.

[0040] Specific implementation method three: A high-temperature multi-axis transmission device cooling structure, the bearing 9 is a tilting pad sliding bearing.

[0041] Other implementations are the same as the second specific implementation.

[0042] Specific implementation method 4: A high-temperature multi-axis transmission device cooling structure, the bearing 9 is made of high-temperature Bas alloy.

[0043] Other implementations are the same as the first specific implementation.

[0044] Specific implementation method 5: A high-temperature multi-axis transmission device cooling structure, an oil return hole 10 is arranged on the lower side of the lower box body 5.

[0045] In this embodiment: cavities are designed in the shaft seal, upper housing, lower housing and sliding bearing to form an oil spray cooling environment, and an oil return hole is provided on the lower side of the lower housing, through which the cooling lubricating oil can return to the interior of the housing.

[0046] Other implementations are the same as the first specific implementation.

[0047] Specific implementation method six: A high-temperature multi-axis transmission device cooling structure, the shaft seal 3 is a gas-liquid shaft seal.

[0048] In this embodiment: the shaft seal is a gas-liquid shaft seal, which can seal gas and oil.

[0049] Other implementations are the same as the first specific implementation.

[0050] Specific implementation method seven: A high-temperature multi-axis transmission device cooling structure, the nozzle 6 is a fan-shaped nozzle.

[0051] In this embodiment, the nozzle is a fan-shaped nozzle, the oil spraying direction of the nozzle is fan-shaped downward, and the oil spraying area axially corresponds to the cooling ring position of the gear shaft.

[0052] The nozzle 6 is a fan-shaped nozzle with a large spraying area and a controllable flow rate after calibration.

[0053] Other implementations are the same as the first specific implementation.

[0054] Specific implementation method eight: A high-temperature multi-axis transmission device cooling structure, the gear shaft 2 is connected to the compressor impeller 1 through end face tooth meshing, and is positioned and fixed by a central bolt connecting rod.

[0055] In this embodiment, the gear shaft is connected to the compressor impeller through face tooth meshing and is positioned and fixed by a central bolt connecting rod, so the connection is firm and easy to assemble and disassemble.

[0056] Other implementations are the same as the first specific implementation.

[0057] Specific implementation method 9: A high-temperature multi-axis transmission device cooling structure, wherein an end surface hollow groove with a depth A is provided on the connecting end surface of the gear shaft 2 and the compressor impeller 1.

[0058] In this embodiment: in addition to designing the end face tooth structure to ensure the torque transmission capability at the end face connecting the gear shaft and the compressor impeller, an additional end face empty groove with a depth A is designed to reduce the contact area between the gear shaft and the compressor impeller, and to reduce the heat transfer of the compressor impeller due to the difference between solid conduction and air conduction.

[0059] Other implementations are the same as the first specific implementation.

[0060] Specific implementation method 10: A design method for a cooling structure of a high-temperature multi-axis transmission device: It includes the following steps:

[0061] Step 1: Design the cooling mechanism infrastructure;

[0062] Step 2: parametrically model all cooling structures and lubricating oil of the gear shaft 2, shaft seal 3, upper box 4, lower box 5, nozzle 6, nozzle seat 7, oil inlet pipe 8 and bearing 9;

[0063] Step 3: Simulate and model the internal flow field of the key parts of the nozzle 6 and the gear shaft 2;

[0064] Step 4: Perform gas-liquid two-phase flow field simulation, analyze the oil distribution of the cooling box at the key position of the bearing 9 at different times under different oil injection flow rates, obtain the change trend of the oil distribution of the gear shaft 2 section at the key position of the bearing 9 over time, and simulate to obtain the convective heat transfer coefficient of the gear shaft 2 section;

[0065] Step 5: Solve the temperature field distribution of the gear shaft 2 section at the key part of the bearing 9, and confirm whether the temperature of each section of the gear shaft 2 meets the use requirements. If it meets the use requirements, proceed to step 6, and if it does not meet the use requirements, proceed to step 2;

[0066] Step 6: Confirm the flow rate of nozzle 6, the shaft section size of gear shaft 2 and the space data of cooling box;

[0067] Step 7: Finally complete the cooling structure design and confirm it.

[0068] When designing the cooling structure: after designing the basic structure of the cooling mechanism, perform parametric modeling on all cooling structures and lubricating oil such as the upper box, lower box, bearings, nozzles, etc.; perform simulation modeling on the internal flow field of key parts such as nozzles and gear shaft sections, perform gas-liquid two-phase flow field simulation, analyze the oil distribution of the cooling box at key parts of the bearing at different times under different injection flow rates, and obtain the change trend of the oil distribution of the gear shaft section at the key part of the bearing over time, and simulate the convective heat transfer coefficient of the gear shaft section; solve the temperature field distribution of the gear shaft section at the key part of the bearing, confirm the nozzle flow, shaft section size and box space data after confirming that the temperature of each shaft section meets the use requirements, and finally complete the structural design confirmation.

Claims

1. A high-temperature multi-axis transmission device cooling structure, characterized in that: It comprises a gear shaft (2), a shaft seal (3), an upper housing (4), a lower housing (5), a nozzle (6), a nozzle seat (7), an oil inlet pipe (8) and a bearing (9); The upper housing (4) and the lower housing (5) are assembled to form a cooling housing. The interior of the cooling housing is arranged as a cavity to form an oil spray cooling environment. The gear shaft (2) passes through the cooling housing. A bearing (9) is arranged between one end of the cooling housing and the gear shaft (2). A shaft seal (3) is arranged between the other end of the cooling housing and the gear shaft (2). The shaft seal (3) is fixedly embedded and installed between the upper housing (4) and the lower housing (5). The gear shaft (2) and the shaft seal (3) are clearance-matched. The other end of the gear shaft (2) is connected to the compressor impeller (1). The nozzle seat (7) is radially inverted and fixedly installed on the upper vertical plate of the upper housing (4). The oil inlet pipe (8) is fixedly installed above the nozzle seat (7) to provide cooling oil. The nozzle (6) is fixedly installed below the nozzle seat (7) to spray cooling oil. The oil spraying area of ​​the nozzle (6) axially corresponds to the cooling ring position of the gear shaft (2). The cooling ring is a stepped shaft section higher than the shaft diameter of the wheel shaft (2).

2. A high temperature multi-axis transmission device cooling structure according to claim 1, characterized in that: The bearing (9) is a sliding bearing, and the gear shaft (2) is floatingly mounted in the bearing (9), and the bearing (9) realizes the radial support function of the gear shaft (2).

3. A high temperature multi-axis transmission device cooling structure according to claim 2, characterized in that: The bearing (9) is a tilting pad sliding bearing.

4. The high temperature multi-axis transmission device cooling structure according to claim 1, characterized in that: The bearing (9) is made of high temperature Bas alloy.

5. The high temperature multi-axis transmission device cooling structure according to claim 1, characterized in that: An oil return hole (10) is provided on the lower side of the lower box body (5).

6. A high temperature multi-axis transmission device cooling structure according to claim 1, characterized in that: The shaft seal (3) is a gas-liquid shaft seal.

7. A high temperature multi-axis transmission device cooling structure according to claim 1, characterized in that: The nozzle (6) is a fan-shaped nozzle.

8. The high temperature multi-axis transmission device cooling structure according to claim 1, characterized in that: The gear shaft (2) is connected to the compressor impeller (1) through end face tooth meshing and is positioned and fixed by a central bolt connecting rod.

9. A high temperature multi-axis transmission device cooling structure according to claim 1, characterized in that: End surface hollow grooves with a depth of A are provided on the connecting end surfaces of the gear shaft (2) and the compressor impeller (1).

10. The design method of the cooling structure according to any one of claims 1 to 9, characterized in that: It includes the following steps: Step 1: Design the cooling mechanism infrastructure; Step 2: parametrically modeling all cooling structures and lubricating oil of the gear shaft (2), shaft seal (3), upper housing (4), lower housing (5), nozzle (6), nozzle seat (7), oil inlet pipe (8) and bearing (9); Step 3: Simulate and model the internal flow field of the key parts of the nozzle (6) and the gear shaft (2); Step 4: Conduct gas-liquid two-phase flow field simulation, analyze the oil distribution of the cooling box at the key position of the bearing (9) at different times under different oil injection flow rates, obtain the change trend of the oil distribution of the gear shaft (2) section at the key position of the bearing (9) over time, and simulate to obtain the convective heat transfer coefficient of the gear shaft (2) section; Step 5: Calculate the temperature field distribution of the gear shaft (2) section at the key position of the bearing (9), and confirm whether the temperature of each section of the gear shaft (2) meets the use requirements. If the temperature meets the use requirements, proceed to step 6; if the temperature does not meet the use requirements, proceed to step 2; Step 6: Confirm the nozzle (6) flow rate, gear shaft (2) shaft section size and cooling box space data; Step 7: Finally complete the cooling structure design and confirm it.

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