Hydroelectric generator set based on phase change cooling

Abstract

The application relates to the technical field of power generation, and particularly provides a water-turbine generator set based on phase change cooling, which aims to solve the problem that the existing water-turbine generator set endangers personal safety due to phase change working medium leakage. To this end, the water-turbine generator set based on phase change cooling comprises a base body, a phase change cooling system and an air cooler, and an optical detection device comprising a light source and a receiver. The rotor assembly comprises a rotor support, and the rotor support is provided with an air inlet hole. When the water-turbine generator set is running, air flows through the stator assembly and the air cooler in sequence, enters the rotor assembly through the air inlet hole, and thus forms a gas circulation loop. The light path formed by the light source and the receiver intersects with the gas circulation loop, so that the optical detection device can detect the gas composition in the air flow. The application detects the gas composition in the gas circulation loop inside the generator set based on the optical detection technology, and the reliability and accuracy of the detection result are higher.

Description

Technical Field

[0001] This application relates to the field of power generation technology, specifically providing a hydro-generator set based on phase change cooling. Background Technology

[0002] A hydro-generator is a generator that converts water energy into electrical energy using a hydro turbine as its prime mover. During the operation of a hydro-generator, its various internal functional components, such as the stator bars, the excitation windings on the rotor, and the generator's brushes and slip rings, continuously generate heat. At the same time, the rotor also generates heat due to mechanical friction and air friction during rotation. Therefore, it is necessary to cool the generator in a timely manner during operation to ensure its normal operation.

[0003] Currently, operating evaporative-cooled hydro-turbine generators rely on the latent heat of vaporization of phase change fluid (PCF) to dissipate heat. PCF has advantages such as high insulation, non-toxicity, and non-corrosiveness. Furthermore, it achieves self-circulation through the pressure difference generated during PCF vaporization, overcoming the problems of high operating pressure and short circuits caused by leaks in traditional water-cooling systems. However, PCF leaks are inevitable during generator operation. While small leaks of gaseous PCF may not pose a significant health hazard, hydro-turbine generators are located in confined spaces, and the specific gravity of gaseous PCF is much greater than that of air. Therefore, when PCF leaks continue, the leaked PCF will gradually sink within this confined space, accumulating at the bottom of the sump. This could lead to oxygen deprivation for workers, endangering their safety.

[0004] Accordingly, a new technical solution is needed in this field to solve the above problems. Summary of the Invention

[0005] This application aims to solve the aforementioned technical problem, namely, to address the issue of personal safety being endangered by the continuous leakage of phase change working fluid in existing hydro-generator units.

[0006] Therefore, this application provides a hydro-generator unit based on phase change cooling, which includes:

[0007] The base body has a sealed space inside, and the base body contains a stator assembly and a rotor assembly.

[0008] A phase change cooling system for cooling the stator assembly;

[0009] An air cooler is disposed on the outer side of the stator assembly along the radial direction of the hydro-generator set;

[0010] An optical detection device, comprising a light source and a receiver opposite to the light source;

[0011] The rotor assembly comprises a rotor support having an air inlet hole, when the hydroelectric generator set is running, the air flow sequentially flows through the stator assembly and the air cooler, and then enters the rotor assembly through the air inlet hole to form a gas circulation loop, the light path formed by the light source and the receiver intersects with the gas circulation loop, so that the optical detection device can detect the gas composition in the air flow.

[0012] In one of the above technical solutions of the hydroelectric generator set, the air inlet hole comprises an upper air inlet hole and a lower air inlet hole arranged in an axial direction of the rotor support, the gas circulation loop comprises a first area surrounding the outside of the upper air inlet hole and the lower air inlet hole, and the light source and the receiver are respectively located on different sides of the first area, so that the light path can pass through the upper air inlet hole and the lower air inlet hole.

[0013] In one of the above technical solutions of the hydroelectric generator set, the gas circulation loop comprises a second area located on the radial outer side of the air cooler of the hydroelectric generator set, and the light source and the receiver are respectively located on different sides of the second area, so that the light path can pass through the second area.

[0014] In one of the above technical solutions of the hydroelectric generator set, the optical detection device further comprises:

[0015] A condenser lens is arranged close to the receiver.

[0016] In one of the above technical solutions of the hydroelectric generator set, the focal point of the condenser lens is located on the light entrance surface of the receiver.

[0017] In one of the above technical solutions of the hydroelectric generator set, the light source, the condenser lens and the receiver are located on the same straight line.

[0018] In one of the above technical solutions of the hydroelectric generator set, the straight line is parallel to the axis of the hydroelectric generator set.

[0019] In one of the above technical solutions of the hydroelectric generator set, the light source is arranged on the frame or bearing of the hydroelectric generator set; and / or

[0020] The receiver is arranged on the frame or bearing of the hydroelectric generator set.

[0021] In one of the above technical solutions of the hydroelectric generator set, the upper air inlet hole and the lower air inlet hole are both arranged in an array along the circumferential direction of the rotor support.

[0022] In one of the above technical solutions of the hydroelectric generator set, the upper air inlet hole and the lower air inlet hole are both arc-shaped holes.

[0023] As described above, in the case of adopting the technical solution described above, the application detects the gas composition in the gas circulation loop of the hydroelectric generating set during operation based on optical detection technology, so as to determine whether there is leakage of working medium in the whole machine. The detection method has strong anti-interference ability and can be stably applied in the complex electromagnetic environment of the generating set. Moreover, compared with the way of sampling and detecting the airflow in the internal environment of the generating set in the prior art, the application detects the airflow in the gas circulation loop of the generating set in a targeted manner according to the air cooling principle of the generating set. The reliability and accuracy of the detection result are higher. At the same time, the application detects the local position in the gas circulation loop by the optical detection device, which can reflect the leakage of gaseous working medium in the whole machine. In this way, the system structure can be simplified and the equipment cost can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0024] The preferred embodiments of the application will be described below with reference to the accompanying drawings, in which:

[0025] Figure 1 is a longitudinal sectional view of a hydroelectric generating set based on phase change cooling according to an embodiment of the application;

[0026] Figure 2 is a schematic view of the airflow circulation path in the hydroelectric generating set.

[0027] In the drawings, the reference signs refer to the following:

[0028] 1, stator assembly; 2, rotor assembly; 21, rotating shaft; 22, rotor support; 221, upper air inlet; 222, lower air inlet; 3, phase change cooling system; 4, air cooler; 5, optical detection device; 51, light source; 52, receiver; 53, condensing lens;

[0029] 100, first region; 101, lower bearing; 102, upper bracket; 103, lower bracket; 104, upper bearing; 200, second region; 300, optical path. DETAILED DESCRIPTION

[0030] The preferred embodiments of the application will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the application and are not used to limit the protection scope of the application. Those skilled in the art can adjust them as needed to adapt to specific application occasions.

[0031] It should be noted that in the description of the present application, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicating the direction or positional relationship are based on the direction or positional relationship shown in the drawings, which is merely for the convenience of description, and does not indicate or imply that the related devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the ordinal numbers "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0032] In addition, it should also be noted that in the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0033] In order to facilitate the understanding of the technical solutions of the present application, first, the cooling principle of the hydroelectric generating set is simply introduced. When the hydroelectric generating set is cooled based on phase change liquid cooling, its cooling is reflected in two aspects, one is the cooling of the phase change cooling system to the stator winding, and the other is the cooling of the air cooler to the rotor and the necessary components such as brush and collector ring, that is, the cooling of the hydroelectric generating set is usually a combination of phase change cooling and air cooling.

[0034] In some related technologies, in order to realize the leakage detection of phase change working medium and ensure the engineering safety, a gas sampling box is installed inside the generator to detect the gas inside the generator to judge the leakage amount of gaseous working medium, and the gaseous working medium is absorbed and treated when the leakage amount is large to ensure the safe operation of the generator set. However, the high-speed circulating airflow in the generator set will dilute the gaseous working medium, so only when the leakage working medium content is high enough, it can be detected, therefore the airflow circulation in the generator set will interfere with the detection process, and the above method is difficult to realize accurate detection of the leakage working medium content, and in order to improve the detection accuracy, the above detection device needs to set enough sampling systems (including sampling box and sampling gas pump) to carry out multi-point detection, which will greatly increase the complexity of the system.

[0035] It can be seen that the above method can detect whether the working medium leaks, but still has significant drawbacks.

[0036] Reference Figure 1For the phase change cooling based hydroelectric generator set according to one embodiment of the present application, it comprises a frame body (not fully shown in the figure), a stator assembly 1, a rotor assembly 2, a phase change cooling system 3, an air cooler 4 and other necessary functional assemblies, and an optical detection device 5 arranged in the frame body.

[0037] The frame body serves as the installation base of the above-mentioned functional assemblies of the generator set, and is mainly used for supporting and fixing the above-mentioned stator assembly 1, rotor assembly 2, end cover and other components. The inside of the frame body is formed with a closed space. The stator assembly 1 comprises a core, a stator winding and other components, and the rotor assembly 2 comprises a rotating shaft 21, a rotor support 22, a magnetic yoke, magnetic poles, a current collecting device and other components. Of course, the above-mentioned functional assemblies of the generator set are all known in the art, and the above-mentioned functional assemblies are only introduced herein for the convenience of describing the technical scheme of the present application. The detailed structure of each functional assembly of the generator set and the connection relationship between each part will not be described herein.

[0038] The phase change cooling system 3 is used for cooling the wire bars in the stator assembly 1. The air cooler 4 is arranged at the outside of the stator assembly 1 along the radial direction of the hydroelectric generator set. The above-mentioned phase change cooling system 3 and air cooler 4 are also known in the art, and the specific structure thereof will not be described herein.

[0039] Referring to Figure 1 and Figure 2 , the optical detection device 5 comprises a light source 51 and a receiver 52 arranged opposite to the light source 51 and used for receiving the light emitted by the light source. The rotor support 22 is provided with an air inlet hole, which specifically comprises an upper air inlet hole 221 and a lower air inlet hole 222 arranged opposite along the axial direction of the rotor support 22. During the rotation of the rotor assembly 2, the airflow in the rotor assembly 2 can move outward along the radial direction under the action of centrifugal force, sequentially pass through the magnetic yoke air duct, the magnetic pole gap and the air gap of the stator assembly 1 of the rotor assembly 2, and finally pass through the air cooler 4. The cooled airflow passing through the air cooler 4 is blocked by the side wall of the frame or the frame body and moves to both sides along the axial direction of the generator set, and then flows inward along the radial direction to the air inlet hole position of the rotor support 22 again under the action of pressure difference (the central region of the generator set, i.e. the air inlet hole position of the rotor support 22 is low pressure), thereby forming a gas circulation loop (the arrow in the figure shows the flow direction of the airflow, i.e. the gas circulation loop). During the circulation of the airflow, heat is taken away by the cold source in the air cooler to the outside, thereby realizing heat exchange. For large hydroelectric generator sets, the air cooling mode is usually the above-mentioned radial ventilation or axial-radial mixed ventilation mode. Figure 1

[0040] ​The light source 51 and receiver 52 are located on different sides of the rotor support 22, and can be mounted on the frame or bearings of the hydro-generator set. For example, in this application Figure 1 In one exemplary embodiment, the light source 51 is mounted on the lower bearing 101, and the receiver 52 is mounted on the upper frame 102. It should be noted that the specific mounting positions of the light source 51 and receiver 52 can be determined according to the specific spatial layout within the hydro-generator unit. For example, when the lower bearing 101 is a guide bearing with a smaller diameter, the light source 51 can be mounted on the lower frame 103; when the upper bearing 104 is a thrust bearing with a larger diameter, the receiver 52 can be mounted on the upper bearing 104. In short, both the light source 51 and receiver 52 can be mounted on the frame or bearing on any side of the rotor support 22. It should be understood that those skilled in the art can adaptively adjust the mounting positions of the light source 51 and receiver 52 according to actual needs, which does not constitute a limitation of this application.

[0041] Reference Figure 2 The gas circulation loop includes a first region 100 (the dashed box on the left in the figure) surrounding the upper air inlet 221 and the lower air inlet 222. The light source 51 and the receiver 52 are located on different sides of the first region 100 along the axial direction of the turbine generator set, so that the light path 300 formed by the light source 51 and the receiver 52 can pass through the upper air inlet 221 and the lower air inlet 222.

[0042] As can be seen from the above, when the hydro-generator unit is running, the gas circulation loop is formed by the centrifugal force during the rotation of the rotor assembly 2. Under the action of centrifugal force, the airflow inside the rotor assembly 2 moves outward along its radial direction and flows back into the rotor support 22 through the upper air inlet 221 and lower air inlet 222 under the action of pressure difference. Therefore, in the entire gas circulation loop, the upper air inlet 221 and lower air inlet 222 and the interior of the rotor support 22 define a narrow channel for the airflow to pass through. Therefore, the airflow is most concentrated in the area near the upper air inlet 221 and lower air inlet 222 (i.e., the first area 100 mentioned above). When the working fluid in the phase change cooling system 3 of the hydro-generator unit leaks, the phase-change gaseous working fluid mixes with the air to form the airflow mentioned above. This airflow will inevitably flow through the first area 100 mentioned above during the circulation process. It is obviously more reliable to detect the first area 100 where the airflow is most concentrated by the optical detection device 5.

[0043] During the operation of the hydro-generator unit, the optical detection device 5 is turned on. The light emitted by the light source 51 passes through the air inlet of the rotor support 22. During this process, the receiver 52 performs optical characteristic analysis on the received light to detect the gas composition in the gas circulation loop, thereby determining whether there is a working fluid leak in the generator unit.

[0044] It should be noted that the above optical detection device 5 detects the composition and concentration of the gaseous working medium by using the absorption, scattering or refraction characteristics of the airflow to the light, which is a known technology in the art. For example, based on the principle of absorption spectrum, when the light emitted by the light source 51 irradiates the airflow, different gas components in the airflow will absorb light of a certain wavelength, resulting in a decrease in light intensity. When the gas component in the airflow is only air, or the gas component in the airflow includes a mixture of air and gaseous working medium, the spectrum generated by the receiver 52 is obviously different, which reflects the change in light intensity. When the leakage of the gaseous working medium is more serious, the concentration of the gaseous working medium is higher, and the change is more obvious. Thus, the composition of the gas in the airflow and the concentration value of the gaseous working medium can be determined.

[0045] As described above, the present application detects the gas composition in the gas circulation loop inside the hydroelectric generator set during operation based on optical detection technology, so as to determine whether there is working medium leakage in the whole machine. The detection method has strong anti-interference ability and can be stably applied in the complex electromagnetic environment of the generator set. Moreover, compared with the sampling and detection method of the airflow in the internal environment of the generator set in the prior art, the present application detects the airflow in the gas circulation loop in a targeted manner according to the air cooling principle of the generator set. The reliability and accuracy of the detection result are higher. Moreover, the present application detects the local position in the gas circulation loop by the optical detection device 5, which can reflect the leakage of the gaseous working medium in the whole machine. Thus, the system structure can be simplified and the equipment cost can be reduced.

[0046] In an embodiment of the present application, a plurality of upper air inlets 221 and lower air inlets 222 are arranged along the circumferential direction of the rotor support 22, and the upper air inlets 221 and the lower air inlets 222 correspond to each other in the axial direction of the rotor support 22. Since the rotor support 22 is in a reciprocating rotary state, the rotor support 22 will block the light signal generated by the light source 51 during the detection process of the optical detection device 5, resulting in that the light signal detected by the receiver 52 is also intermittent. Arranging a plurality of upper air inlets 221 and lower air inlets 222 along the circumferential direction of the rotor support 22 not only helps to form the gas circulation loop and improve the air cooling efficiency, but also improves the blocking phenomenon of the light signal by the rotor support 22.

[0047] Further, the upper air inlets 221 and the lower air inlets 222 are arranged as arc-shaped holes, and the arc-shaped tracks of the arc-shaped holes extend along the circumferential direction of the rotor support 22. Arranging the upper air inlets 221 and the lower air inlets 222 as arc-shaped holes is beneficial to improving the continuity of the light signal, so that the spectrum generated by the receiver 52 is more intuitive, and thus is beneficial to the analysis of the gas composition.

[0048] Reference Figure 2, the second area 200 is located between the air cooler 4 and the machine foundation, and the airflow from the rotor support 22 is diverted (moves axially upward and downward) in the second area 200 after passing through the air cooler 4 along the radial direction, so that the airflow in the second area 200 is relatively concentrated. Based on this, in an embodiment of the present application, the light source 51 and the receiver 52 are arranged on the upper and lower sides of the second area 200 respectively, so that the above-mentioned light path 300 can pass through the second area 200 and detect the gas composition of the airflow in the second area 200.

[0049] It should be noted that the drawings of the present application are a longitudinal sectional view of the hydroelectric generator set, so the first area 100 and the second area 200 are rectangular areas in the drawings, but in fact the first area 100 and the second area 200 are annular spaces formed by rotating the rectangular areas in the drawings by 360°, but the optical detection device 5 only needs to be arranged in one longitudinal section of the annular space.

[0050] It should be further noted that for the above-mentioned first area 100 and second area 200, they are two areas with relatively concentrated airflow density in the entire gas circulation loop of the generator set. In the actual size design of the generator set, the inlet of the rotor support 22 usually has a small radial size, so that the first area 100 has a small radial size and presents a relatively narrow airflow passage, while the outer side of the air cooler 4, i.e. the second area 200, usually presents a relatively large radial size due to the constraints of engineering maintenance and other factors, so that the second area 200 has a larger radius of revolution than the first area 100. On the other hand, the airflow in the first area 100 is affected by the pressure difference and has a high speed and a high concentration, while the airflow in the second area 200 is affected by the machine foundation and presents a relatively irregular motion path.

[0051] Therefore, in combination with the internal space layout and airflow motion characteristics of the generator set, the airflow in the first area 100 is more concentrated than that in the second area 200, and the concentration detection of the gaseous working medium in the airflow in the first area 100 is more valuable. However, the upper and lower sides of the second area 200 are not blocked, while the first area 100 is intermittently blocked by the rotor support 22. In practical applications, those skilled in the art can choose to install the optical detection device 5 in any of the above-mentioned areas according to the needs, and the present application does not limit this.

[0052] Although the first region 100 and the second region 200 are taken as examples in the above embodiments of the present application, the present application is not limited thereto, and in some other embodiments, as long as the optical path 300 formed by the light source 51 and the receiver 52 can intersect with the gas circulation loop, the light emitted by the light source 51 can pass through the gas circulation loop, and the composition of the gas in the gas flow can be detected.

[0053] With reference to Figure 1 and Figure 2 In an embodiment of the present application, the optical detection device 5 further comprises a condenser lens 53, which is arranged close to the receiver 52. The condenser lens 53 is used to converge the light emitted by the light source 51, so as to reduce the scattering of the light to the surroundings during the propagation of the light along the optical path 300, thereby increasing the intensity of the light and being more conducive to the analysis of the composition of the gas in the gas flow. The condenser lens 53 can be fixed to the frame, the bearing or other positions by a support structure or the like, and the present application is not limited thereto. Optionally, when the condenser lens 53 is installed, the distance between the condenser lens 53 and the receiver 52 can be adjusted, so that the focal point of the condenser lens 53 is located on the light entrance surface of the receiver 52, so as to maximize the intensity of the light signal.

[0054] In an implementation manner, the light source 51, the condenser lens 53 and the receiver 52 are located on the same straight line, so that the length of the optical path can be shortened, the optical loss can be reduced, and the quality of the light signal can be improved.

[0055] Further, the straight line formed by the light source 51, the condenser lens 53 and the receiver 52 (i.e. the trajectory of the optical path 300) is parallel to the axis of the hydroelectric generator set. Since the first region 100 and the second region 200 are both rectangular regions, when the straight line trajectory of the optical path 300 is parallel to the axis of the hydroelectric generator set, more gas flow can be passed through, thereby improving the reliability and accuracy of the analysis of the composition of the gas.

[0056] Finally, it should be noted that the above light source 51 of the present application can be a general light source or a laser, and the light source 51 can be a single point light source or a light source array composed of multiple point light sources. The condenser lens 53 can be a convex lens or a Fresnel lens, and can be a single lens or a lens array composed of multiple lenses. In summary, the present application does not limit the specific type, number and arrangement form of the above light source 51 and condenser lens 53, and those skilled in the art can adaptively adjust them according to the actual needs, and such adjustment is within the protection scope of the present application.

[0057] So far, the technical solution of the present application has been described in combination with the preferred embodiments shown in the drawings, but it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical solutions after the changes or replacements will all fall within the protection scope of the present application.

Claims

1. A phase change cooling based hydroelectric generating unit characterized in that, include: The base body has a sealed space inside, and the base body has a stator assembly (1) and a rotor assembly (2). A phase change cooling system (3) is used to cool the stator assembly (1); An air cooler (4) is disposed on the outer side of the stator assembly (1) along the radial direction of the turbine generator set; An optical detection device (5) includes a light source (51) and a receiver (52) opposite to the light source (51). The rotor assembly (2) includes a rotor support (22), which has an air inlet. When the hydro-generator unit is running, the airflow flows through the stator assembly (1) and the air cooler (4) in sequence and then enters the rotor assembly (2) through the air inlet to form a gas circulation loop. The light path (300) formed by the light source (51) and the receiver (52) intersects with the gas circulation loop so that the optical detection device (5) can detect the gas composition in the airflow. The air inlet includes an upper air inlet (221) and a lower air inlet (222) arranged opposite each other along the axial direction of the rotor support (22). The gas circulation loop includes a first region (100) surrounding the upper air inlet (221) and the lower air inlet (222). The light source (51) and the receiver (52) are located on different sides of the first region (100) so that the optical path (300) can pass through the upper air inlet (221) and the lower air inlet (222).

2. The hydroelectric generating unit of claim 1, wherein The optical detection device (5) further includes: A focusing lens (53) is positioned close to the receiver (52).

3. The hydroelectric generating unit of claim 2, wherein, The focal point of the condenser lens (53) is located on the light-incident surface of the receiver (52).

4. The hydroelectric generating unit of claim 2, wherein The light source (51), the condenser lens (53), and the receiver (52) are located on the same straight line.

5. The hydro-generator set according to claim 4, characterized in that, The straight line is parallel to the axis of the hydro-generator unit.

6. The hydro-generator set according to claim 2, characterized in that, The light source (51) is mounted on the frame or bearing of the hydro-generator unit; The receiver (52) is mounted on the frame or bearing of the hydro-generator unit.

7. The hydro-generator set according to claim 1, characterized in that, Both the upper air inlet (221) and the lower air inlet (222) are arranged in multiple circumferential arrays along the rotor support (22).

8. The hydro-generator set according to claim 7, characterized in that, Both the upper air inlet (221) and the lower air inlet (222) are arc-shaped holes.

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