Compression expansion integrated machine

Abstract

The application discloses a compression-expansion integrated machine, which comprises a compressor unit, an expander unit, a motor unit and a circulating heat exchange system. The expander impeller is drivenly connected with the compressor main shaft, and the motor main shaft is connected with the compressor main shaft through a shaft coupling. The circulating heat exchange system comprises a heat exchange medium outlet communicated with a compressor inlet flow channel, a heat exchange flow channel communicated with the outlet, and the heat exchange flow channel is further communicated with the compressor unit inlet channel. The heat exchange medium in the heat exchange flow channel flows through the electromagnetic bearing supporting the compressor main shaft and / or the motor main shaft and the motor stator of the motor unit, and exchanges heat with the electromagnetic bearing and the motor stator. The application uses the mild and stable working medium on the compressor side as the heat exchange medium, can effectively isolate the interference of the extreme temperature on the expander side to the precision components such as the electromagnetic bearing, and provides necessary cooling or heat preservation, so that the bearing can stably work in the optimal temperature range.

Description

Technical Field

[0001] This invention relates to the field of rotating machinery, and more specifically to an integrated compression and expansion machine. Background Technology

[0002] In fields such as energy, chemical engineering, and air separation, it is often necessary to compress and expand gases to perform work. Traditional solutions treat the compressor, expander, and drive motor as independent devices, connected by pipes and couplings. This split layout suffers from problems such as a large system size, large footprint, complex shaft alignment, and significant pipeline losses, resulting in low overall efficiency and high manufacturing and maintenance costs.

[0003] To improve system compactness and efficiency, attempts have been made to integrate the compressor and expander onto the same shaft system. However, this integration brings new technical challenges. Expanders typically operate in extreme temperature conditions, such as high temperatures (e.g., 500°C) or cryogenic temperatures (e.g., -200°C). Their heat (or cold) can leak through structural heat conduction or minor leaks in seals, severely impacting the operating environment of critical compressor-side components (such as the bearings supporting the rotor). This is especially true for solutions employing high-precision, high-sensitivity electromagnetic bearings, which have strict requirements on their operating temperature range. Extreme temperatures can cause changes in the properties of magnetic materials and failure of electronic components, seriously threatening the operational safety and stability of the bearings and even the entire unit.

[0004] On the other hand, in integrated units, components such as motors and bearings generate heat during operation, requiring effective heat dissipation. Using external cooling systems (such as water cooling or independent air cooling) not only increases system complexity and external dependence but also carries risks of sealing problems, corrosion, or contamination due to the introduction of cooling media of varying quality. Furthermore, traditional cooling methods are difficult to adjust flexibly and precisely according to the actual operating conditions of the unit, failing to achieve efficient energy utilization while ensuring cooling effectiveness.

[0005] Therefore, there is an urgent need for a new type of integrated compressor-expander unit. It not only needs to achieve a highly compact integration of the compressor, expander, and motor, but also needs to incorporate a high-efficiency, adaptive heat exchange system that is integrated with the main process to solve the thermal management problem under extreme temperature conditions, ensure the reliable operation of precision components such as electromagnetic bearings, and improve the energy efficiency and integration level of the entire system. Summary of the Invention

[0006] The purpose of this invention is to overcome the aforementioned deficiencies of the prior art and provide an integrated compression-expansion machine. This integrated machine, through its unique structural integration and built-in closed-loop heat exchange system, achieves a highly compact design, stable operation, and efficient energy utilization.

[0007] To achieve the above objectives, the present invention provides an integrated compression-expansion machine, which includes a compressor unit, an expander unit, a motor unit, and a circulating heat exchange system. The integrated compression-expansion machine includes: a compressor unit, and an expander unit and a motor unit located on both sides of the compressor unit; The expander impeller of the expander unit is drivenly connected to the compressor main shaft of the compressor unit; the motor main shaft of the motor unit is connected to the compressor main shaft via a coupling; and A circulating heat exchange system includes: The heat exchange medium outlet is located on the compressor unit and is connected to the compressor intake passage; The heat exchange channel has one end connected to the heat exchange medium outlet and the other end connected to the air intake channel of the compressor unit. The heat exchange medium in the heat exchange channel flows through the electromagnetic bearings supporting the compressor main shaft and / or the motor main shaft, as well as the motor stator of the motor unit, and exchanges heat with the electromagnetic bearings and the motor stator.

[0008] Optionally, the heat exchange channel is equipped with a variable frequency fan and a heat exchanger, and the variable frequency fan is used to adjust the flow rate of the heat exchange medium in the heat exchange channel.

[0009] Optionally, the heat exchange channel extends from a radial hole in the outer cylinder of the compressor.

[0010] Optionally, the heat exchange medium outlet is located on the left or right end cover of the compressor unit, and the left or right end cover of the compressor is used to form the compressor inlet air passage.

[0011] Optionally, the motor unit is connected to the part of the compressor unit corresponding to the low-temperature air intake area.

[0012] Optionally, the compressor spindle and the motor spindle are each supported by independent electromagnetic bearing assemblies.

[0013] Optionally, the expander unit is sealed to the compressor unit via a flange structure.

[0014] Optionally, the compressor unit includes at least two stages of compression impellers arranged back-to-back on the compressor main shaft.

[0015] Optionally, the electromagnetic bearing is provided with a plurality of axial holes along the circumferential direction for the heat exchange medium to flow through.

[0016] Optionally, an interstage seal (21) is provided between the expander unit and the compressor unit; when the expander side pressure is higher than the compressor side pressure, the interstage seal is a comb seal; when the expander side pressure is lower than the compressor side pressure, the interstage seal is a carbon ring seal.

[0017] Through the above design, this invention utilizes the relatively mild and stable working fluid on the compressor side as the heat exchange medium to construct a self-sufficient, controllable, and adjustable active temperature control system. This system can effectively isolate the interference of extreme temperatures on the expander side on precision components such as bearings, while providing necessary cooling or insulation for the motor and bearings, ensuring that the electromagnetic bearings operate stably within the optimal temperature range, and greatly improving the reliability and efficiency of the entire integrated machine under harsh operating conditions. Attached Figure Description

[0018] Figure 1 This is a schematic cross-sectional view of the overall structure of an integrated compression and expansion machine provided in an embodiment of the present invention; Figure 2 for Figure 1 Flowchart of the circulating heat exchange system of the integrated compression expander.

[0019] Explanation of icon numbers: 1- Compressor outer cylinder; 2- Compressor right end cover; 3- Compressor inner cylinder; 4- First stage diaphragm; 5- Intermediate diaphragm; 6- Second stage diaphragm; 7- Compressor left end cover; 8- Compressor main shaft; 9- First stage compressor impeller; 10- Second stage compressor impeller; 11- Shaft sleeve seal; 12- Shaft sleeve; 13- Intermediate seal; 14- Shaft sleeve; 15- Shaft sleeve seal; 16- Expander housing; 17- Nozzle; 18- Expander end cover; 19- Expander impeller; 2 0-Tie rod nut; 21-Interstage seal; 22-Motor housing; 23-Motor spindle; 24-Motor stator; 25, 26-Compressor electromagnetic bearing; 27, 28-Motor electromagnetic bearing; 29-Coupling; 30-Variable frequency fan; 31-Heat exchanger; 32-First-stage intake passage; 33-First-stage exhaust passage; 34-Second-stage intake passage; 35-Second-stage exhaust passage; 36-Axial bore; 37-Heat exchange medium outlet; 38-Heat exchange flow channel. Detailed Implementation

[0020] The integrated compression and expansion machine of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, only for the purpose of conveniently and clearly illustrating the embodiments of the present invention. Please refer to the drawings to make the objectives, features, and advantages of the present invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives achieved by the present invention, should still fall within the scope of the technical content disclosed in the present invention.

[0021] refer to Figure 1 The integrated compression and expansion unit in this embodiment mainly includes an expander unit, a compressor unit, a motor unit, and an integrated circulating heat exchange system.

[0022] The compressor unit includes an outer compressor cylinder 1, an inner compressor cylinder 3 disposed within the outer compressor cylinder 1, and a compressor main shaft 8 passing through the inner cylinder. At least one stage of compression impellers is mounted on the compressor main shaft 8. In this preferred embodiment, two-stage compression is employed, with the first-stage compression impeller 9 and the second-stage compression impeller 10 arranged back-to-back on the compressor main shaft 8 to effectively balance axial forces. An intermediate seal 13 is provided between the two-stage compression impellers. The compressor unit has a left end cover 7 and a right end cover 2 at both ends, which, together with the outer compressor cylinder 1 and the inner cylinder 3, form the compressor's intake passages 32 and 34 and exhaust passages 33 and 35.

[0023] The compressor main shaft 8, compressor first-stage impeller 9, compressor second-stage impeller 10, shaft sleeve seal 11, shaft sleeve 12, shaft sleeve 14 and shaft sleeve seal 15 constitute the rotor of the compressor unit. The compressor first-stage impeller 9, compressor second-stage impeller 10, shaft sleeve seal 11, shaft sleeve 12, shaft sleeve 14 and shaft sleeve seal 15 are all thermally fitted onto the compressor main shaft 8.

[0024] Specifically, the compressor's primary intake passage 32 consists of the compressor outer cylinder 1, the compressor right end cover 2, the primary partition 4, and the bushing 12; the primary exhaust passage 33 consists of the primary partition 4, the compressor inner cylinder 3, and the compressor outer cylinder 1. The compressor's secondary intake passage 34 consists of the compressor outer cylinder 1, the compressor left end cover 7, the secondary partition 6, and the bushing 14; the secondary exhaust passage 35 consists of the secondary partition 6, the compressor inner cylinder 3, and the compressor outer cylinder 1.

[0025] The expander unit is located on the left side of the compressor unit and includes an expander housing 16 and an expander impeller 19 inside. The expander impeller 19 is driven to the left end of the compressor main shaft 8 via end face teeth and a tie rod nut 20 to transmit torque. The expander housing 16 is sealed to the compressor outer cylinder 1 via flange bolts. An expander end cover 18 is also provided between the expander housing 16 and the left end cover 7 of the compressor. An interstage seal 21 is provided between the expander unit and the compressor unit. Depending on the pressure difference between the two sides, the interstage seal 21 can be of different forms: when the pressure on the expander side is higher than that on the compressor side, a comb-tooth seal is used; otherwise, a carbon ring seal is used to optimize the sealing effect and reduce leakage. The expander housing 16 is provided with an air inlet, and after the gas enters, it is guided by a nozzle 17 to drive the expander impeller 19 to rotate.

[0026] The motor unit is located on the right side of the compressor unit and includes a motor housing 22, a motor spindle 23 inside, and a surrounding motor stator 24. The motor spindle 23 is connected to the right end of the compressor spindle 8 via a coupling 29. The connection between the motor spindle 23 and the compressor spindle 8 can be flexible. The motor housing 22 is mounted on the compressor outer cylinder 1 via a flange connection structure, and the connection position corresponds to the low-temperature intake area of ​​the compressor. This keeps the motor unit away from the high-temperature or cryogenic expander side, placing it in a relatively mild operating environment.

[0027] The compressor main shaft 8 and the motor main shaft 23 are each supported by independent electromagnetic bearing assemblies. Specifically, the compressor main shaft 8 is supported by compressor electromagnetic bearings 25 and 26 located at both ends; the motor main shaft 23 is supported by motor electromagnetic bearings 27 and 28. These electromagnetic bearings have multiple axial holes along the circumferential direction on their bearing bodies to allow the heat exchange medium to flow smoothly through the bearing interior, achieving efficient heat exchange.

[0028] The compressor electromagnetic bearing 25 is located on the right side of the expander end cover 18 and the expander interstage seal 21. Due to the special temperature conditions of the expander, whether through heat transfer via the expander end cover 18 or through minor leakage via the expander interstage seal 21, the operation of the compressor electromagnetic bearing 25 will inevitably be affected. The compressor electromagnetic bearings 25 and 26, and the motor electromagnetic bearings 27 and 28, generate a certain amount of heat during operation due to their physical properties. To ensure the reliability of the electromagnetic bearing operation, a simple and reliable circulating heat exchange system is required to meet the functional requirements.

[0029] refer to Figure 1 and Figure 2 The working process of the circulating heat exchange system of the present invention is as follows: The heat exchange medium (i.e., part of the compressor working fluid) is drawn out from the compressor inlet passage 34 through the heat exchange medium outlet 37 opened on the compressor unit. This outlet can be opened on the left end cover 7 or the right end cover 2 of the compressor, preferably on the lower half-circumference of the end cover, and can be designed as an oblique hole 37 to facilitate flow. In this embodiment, the compressor uses a two-stage impeller compression. The heat exchange medium outlet 37 is connected to the two-stage inlet passage 34 and is opened on the lower half-circumference of the left end cover 7 of the compressor. Multiple openings 36 are evenly distributed around the middle section of the right end cover 2 of the compressor to facilitate the flow of these heat exchange media.

[0030] The extracted medium enters the heat exchange channel 38. Channel 38 first flows through the compressor electromagnetic bearing 25 near the expander side, actively compensating for the extreme temperature effects caused by heat conduction from the expander end cover 18 or by minor leakage of working fluid through the interstage seal 21 (cooling or heating). Subsequently, the medium flows sequentially through the compressor electromagnetic bearing 26, motor electromagnetic bearings 27 and 28 on the other side, providing cooling for the motor stator 24.

[0031] The flow channel 38 is equipped with a variable frequency fan 30 as a drive and adjustment component. It provides circulation power and can precisely control the flow rate of the heat exchange medium by adjusting the speed, thereby flexibly adjusting the heat exchange intensity of each component.

[0032] Driven by the variable frequency fan 30, the medium continues to flow through the heat exchanger 31. The heat exchanger 31 can perform secondary temperature regulation on the medium, for example, cooling it after it has absorbed heat from the bearings and motor, or heating it when it is necessary to keep the bearings warm (such as in the case of deep cryogenic conditions of the expander).

[0033] Finally, the temperature-controlled medium is sent back to the compressor unit's intake channel through the reflux port, re-entering the main process flow, forming a completely closed internal loop that does not exchange media with the outside.

[0034] Based on the core concept of this invention, further improvements can be made to the integrated compression and expansion machine. These improvements, without departing from the overall design concept of this invention, should also fall within the protection scope of this invention.

[0035] Specifically, regarding the arrangement of impellers in the compressor unit, in addition to the aforementioned back-to-back arrangement, single or multiple impellers can also be arranged in a parallel configuration. Different parallel configurations result in different inlet and outlet orientations, and the selection of the air source and flow path design of the corresponding circulating heat exchange system are also adjusted accordingly. However, they all follow the closed-loop heat exchange principle proposed in this invention: "air is drawn from the compressor inlet flow channel - flows through the bearing / motor for heat exchange - is regulated by the heat exchanger - and flows back to the inlet flow channel."

[0036] The integrated machine shown in the figure omits some gas pipelines. The gas first enters through the primary intake channel 32, is pressurized, and then discharged through the primary exhaust channel 33. The discharged high-pressure gas enters the secondary intake channel 34 after passing through the heat exchanger 31, is pressurized again, and then discharged through the secondary exhaust channel 35. The discharged gas then enters the expander unit.

[0037] Example 1: The air inlet is located on the expander unit side, and the exhaust port is located on the high-speed motor unit side. In this arrangement, the environment of the compressor electromagnetic bearing 25 near the expander side is similar to that in the previous embodiment. Its circulating heat exchange system is designed the same as in the previous embodiment, that is, air is drawn from the compressor inlet air passage (such as through the left end cover 7 of the compressor), flows through the bearing and merges with other flow paths, and then flows back after passing through the variable frequency fan 30 and the heat exchanger 31.

[0038] Example 2: The air inlet is located on the high-speed motor side, and the exhaust outlet is located on the expansion unit side. In this arrangement, the air source for the circulating heat exchange system is mainly taken from the bottom space of the compressor's first-stage inlet air passage 32. Specifically, by opening an air vent in the lower semicircle of the compressor's right end cover 2, the low-temperature medium in the first-stage inlet air passage 32 is introduced into the internal cavity of the compressor's electromagnetic bearing 26 structure near the motor side. In addition, a small amount of air can be obtained from the sealing leakage gas of the bushing seal 11.

[0039] To meet the heat exchange requirements of the compressor electromagnetic bearing 25 near the expander side, corresponding pipelines and instrument controls can be designed to lead out a portion of the heat exchange gas source through the radial holes on the compressor outer cylinder 1, and then through the connecting pipeline on the outer cylinder, into the corresponding radial holes of the compressor outer cylinder 1 and the compressor left end cover 7, thereby introducing the compressor electromagnetic bearing 25 for sufficient heat exchange. The heat-exchanged medium is then led out through the radial holes of the compressor left end cover 7 and the compressor outer cylinder 1.

[0040] Meanwhile, in order to meet the heat exchange requirements of the motor unit, the variable frequency fan 30 is adjusted so that another part of the heat exchange air source flows through the motor electromagnetic bearing 27, the motor stator 24 and another motor electromagnetic bearing 28 in sequence for heat exchange.

[0041] The two heat exchanged media converge before the inlet of the variable frequency fan 30 and are driven by the fan to flow through the interstage heat exchanger 31 for temperature regulation. Finally, they flow together with the main compressed medium into the first stage intake channel of the compressor to complete a complete closed-loop heat exchange process.

[0042] This improved design demonstrates that regardless of the compressor impeller arrangement, the circulating heat exchange system can always utilize the low-temperature medium on the compressor intake side as a stable gas source through adaptive design. Furthermore, the flow path can be flexibly allocated according to the actual location and heat exchange requirements of each component, ultimately achieving precise temperature management for all critical components (especially the electromagnetic bearing). This perfectly aligns with and extends the core concept of this invention. If the expander unit uses a low-temperature medium, the heat exchange gas source can heat the space temperature of the compressor electromagnetic bearing 25; if the expander unit uses a high-temperature medium, applying an insulating coating or using insulating material on the electromagnetic bearing side of the expander end cover 18 allows the heat exchange gas source to cool the space temperature of the compressor electromagnetic bearing 25.

[0043] This circulating heat exchange system has multiple beneficial effects: Active thermal management: Creates an independent and controllable temperature environment, utilizing the relatively mild working fluid on the compressor side to effectively resist the thermal interference of extreme conditions (high temperature or deep cold) of the expander on the precision electromagnetic bearing, ensuring that it always works in the optimal temperature range.

[0044] System self-consistency and simplification: The system uses its own working fluid for heat exchange, eliminating the need for external cooling water sources or complex independent air ducts. This simplifies the system structure and avoids potential pollution, corrosion, or pressure matching problems caused by the introduction of external media.

[0045] Intelligent regulation and energy saving: The flow rate can be steplessly regulated by the variable frequency fan, and the heat exchange intensity can be precisely controlled according to the actual operating conditions of the unit (such as load and expander side temperature) to achieve on-demand heat exchange, which is energy-saving and efficient.

[0046] Improved overall reliability: By placing the motor unit on the low-temperature side of the compressor and combining it with the cooling of the motor stator, the operating temperature of the motor is further reduced, thereby improving the motor's operating efficiency, insulation life and overall reliability.

[0047] High integration and compactness: The entire heat exchange system is built into an integrated structure and organically integrated with the main process flow channel, achieving a high degree of equipment compactness.

[0048] In summary, this invention, through its innovative coaxial integrated structure of "compressor-expander-motor" and built-in intelligent closed-loop heat exchange system, successfully solves the core challenges of thermal management and operational reliability of integrated compressor-expander under extreme temperature conditions, achieving highly compact, efficient, stable, and safe operation of the equipment.

[0049] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0050] In the description of this invention, it should be understood that the terms "center," "height," "thickness," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0051] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0052] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0053] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A compression and expansion integrated machine, characterized by, include: A compressor unit, and an expander unit and a motor unit located on both sides of the compressor unit; The expander impeller (19) of the expander unit is driven to be connected to the compressor main shaft (8) of the compressor unit; the motor main shaft (23) of the motor unit is connected to the compressor main shaft (8) through a coupling (29); as well as A circulating heat exchange system includes: The heat exchange medium outlet (37) is located on the compressor unit and is connected to the compressor intake passage; The heat exchange channel (38) is connected at one end to the heat exchange medium outlet (37) and at the other end to the air intake channel of the compressor unit. The heat exchange medium in the heat exchange channel (38) flows through the electromagnetic bearings supporting the compressor main shaft (8) and / or the motor main shaft (23) and the motor stator (24) of the motor unit, and exchanges heat with the electromagnetic bearings and the motor stator (24).

2. The integrated compression and expansion machine as described in claim 1, characterized in that, The heat exchange channel (38) is equipped with a variable frequency fan (30) and a heat exchanger (31). The variable frequency fan (30) is used to adjust the flow rate of the heat exchange medium in the heat exchange channel (38).

3. The integrated compression and expansion machine as described in claim 1, characterized in that, The heat exchange medium outlet (37) is located on the left end cover (7) or right end cover (2) of the compressor unit.

4. The integrated compression and expansion machine as described in claim 3, characterized in that, The heat exchange channel (38) is drawn out from the radial hole of the compressor outer cylinder (1).

5. The integrated compression and expansion machine as described in claim 1, characterized in that, The motor unit is connected to the compressor unit at the location corresponding to the low-temperature air intake area.

6. The integrated compression and expansion machine as described in claim 1, characterized in that, The compressor spindle (8) and the motor spindle (23) are each supported by an independent electromagnetic bearing assembly.

7. The integrated compression and expansion machine as described in claim 1, characterized in that, The expander unit is sealed to the compressor unit via a flange structure.

8. The integrated compression and expansion machine as described in claim 1, characterized in that, The compressor unit includes at least two stages of compression impellers arranged back-to-back on the compressor main shaft (8).

9. The integrated compression and expansion machine as described in claim 1, characterized in that, The electromagnetic bearing has multiple axial holes along its circumference to allow the heat exchange medium to flow through.

10. The integrated compression and expansion machine as described in claim 1, characterized in that, An interstage seal (21) is provided between the expander unit and the compressor unit; when the expander side pressure is higher than the compressor side pressure, the interstage seal (21) is a comb seal; when the expander side pressure is lower than the compressor side pressure, the interstage seal (21) is a carbon ring seal.

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