JPH0951655A - Turbine generator rotor coil end cooling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cooler for rotor coil end in which the cooling performance for each coil end can be enhanced by feeding the coolant gas which has cooled the rotor coil end of a turbine generator thereby increasing the quantity of coolant gas being discharged to the outside from an exhaust chamber. SOLUTION: A coolant gas flow 17B flowing through a coolant gas channel 16B extending perpendicularly to the rotor shaft 2 of at the end 9 of rotor coil is discharged to the outside of a rotor core 8 through an vent 19 made axially through a rotor shaft 2 at the position where an exhaust chamber 13 is located, an exhaust chamber vent 20 and a rotor core vent 21 made radially through the rotor shaft 2 and rotor core 8, respectively, while communicating with the vent 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to cooling of a turbine generator main body by introducing a refrigerant gas from an air cooler and a gas cooler into a machine by a fan, particularly for a thermal power turbine, a gas turbine, and a combined cycle. The present invention relates to a cooling device that cools a coil end of a rotor winding of a turbine generator.

[0002]

2. Description of the Related Art FIGS. 2 to 4 are sectional views of a turbine generator of a gas cooling system in which a generator body is cooled by a fan provided at the end of a rotor shaft. FIG. FIG. 3 is a perspective sectional view showing a cooling device of a coil end of a rotor winding of a conventional turbine generator without a retaining ring, and FIG. 4 is a refrigerant gas passage of the coil end of FIG. It is a perspective view which shows the principal part of a cooling device. Cooling of the turbine generator body is done by coil end 1 of the stator winding.
Of the refrigerant gas from a gas cooler (not shown) provided in the stator frame 4 by driving the axial fan 3 provided at the end of the rotor shaft 2 located near both ends of the stator frame 4. It is carried out by introducing the rotor shaft 2 into the machine from both ends of the rotor shaft 2. The refrigerant gas 6 sucked into the machine is divided into a refrigerant gas flow 6A that cools the coil ends 1 of the stator windings and the stator core 7, and a refrigerant gas flow 6B that flows in the axial direction of the rotor shaft 2.

The refrigerant gas flow 6B ventilated in the axial direction of the rotor shaft 2 is composed of a plurality of saddle-shaped coils wound around a rotor core 8 in a multiple annular shape whose outer periphery is covered and held by a retaining ring 9a. The convection on the surface of the coil end 9 of the rotor winding passes through the ventilation hole 10 (see FIG. 3 described later) provided in the rotor core 8 and the duct provided in the radial direction of the stator core 7, as described above. A closed ventilation system is adopted in which the stator core 7 is cooled and heated together with the heated refrigerant gas flow 6A to the gas cooler in the back space of the stator core 7 to be cooled and then circulated to the inside of the machine again.

By the way, the operating temperature of a rotating electric machine depends on the heat-resistant life characteristics of the insulating material that coats the winding conductors that form the winding, and in particular, as in a turbine generator, the rotor coil has a large temperature in the longitudinal direction. If there is a difference, the coil end 9 of the rotor winding arranged so as to project from the rotor core 7 in the axial direction as shown in FIG. It is necessary to set the conductor current density of the rotating electric machine so that the insulating material of No. 9 does not exceed the heat resistance life, which affects the output capacity of the generator. Therefore, the cooling structure of the coil end 9 of the rotor winding of the rotating electric machine is improved, the temperature increase of the coil end 9 is suppressed, and the cross-sectional area of the winding conductor is not increased. A rotor coil cooling device capable of increasing output is disclosed by the same applicant as that of the present invention in Japanese Patent Laid-Open No. Hei 7
It has been filed as Japanese Patent Publication No. -75272.

As shown in FIGS. 3 and 4, the invention disclosed in Japanese Patent Laid-Open No. 7-75272 is provided with an insulating material partition wall 11 in the gap between the inner peripheral side of the coil end 9 and the rotor shaft 2.
The circumference of the rotor shaft 2 is divided into a supply chamber 12 and an exhaust chamber 13 for the refrigerant gas flow 6B in the circumferential direction. The refrigerant gas flow 6B supplied through the through holes 14 formed at the corners between the coil ends 9 of the insulating material partition wall 11.
Is composed of the insulating material 15 with protrusions provided on both side surfaces of the plate-shaped portion 15A, which is provided on each of the planes parallel to the rotor shaft 2 between the coil ends 9 and orthogonal to each other. The refrigerant gas passages 16 </ b> A and 16 </ b> B meander in a zigzag shape between the coil ends 9. The refrigerant gas flow 17 flowing in zigzag along the refrigerant gas passage 16A
After forcibly cooling the coil end 9, A is discharged from the outer peripheral surface of the rotor core 8 through the vent holes 10 penetrating the rotor core 8, and the refrigerant gas flow that flows zigzag along the refrigerant gas passage 16B. Reference numeral 17B denotes the exhaust chamber 1 defined adjacent to the supply chamber 12 after the coil end 9 is forcibly cooled.
It is configured to be discharged from the exhaust groove 18 at the end of the rotor core 7 through the nozzle 3. As a result, the coil end 9 can be forcibly cooled by ventilation, so that the cooling performance of the coil end 9 can be improved.

[0006]

However, in the cooling device of the invention described in the above-mentioned Japanese Patent Laid-Open No. 7-75272, the corend 9 is pressurized in the supply chamber 12 and accelerated through the through hole 14. The flow path of the refrigerant gas flow 17B flowing along the plane orthogonal to the rotor axis 2 of the is, after flowing to the refrigerant gas passage 16B in the circumferential direction of the coil end 9,
The rotor shaft 2 changes its direction to the axial direction, flows into the exhaust chamber 13, and ventilates in the direction of the exhaust groove 18. Therefore, there is a large flow resistance of the refrigerant gas flow 17B flowing in the zigzag shape between the coil ends 9 in the circumferential direction between the protrusions 15B and flowing into the exhaust chamber 13, and also flowing between the coil ends 9. Since the flow velocity of each refrigerant gas flow 17B also varies depending on the dimensional length of the coil end 9, the amount of refrigerant gas in the circumferential direction of the coil end 9 becomes non-uniform, and the temperature difference occurs at each coil end 9 at the axial end. There was a problem of coming out. For this reason, the discharge amount of the heated refrigerant gas flow 17B flowing into the exhaust chamber 13 to the outside of the rotor core 8 is increased to increase the resistance of the refrigerant gas flow 17B to the exhaust chamber 13 described above. In order to reduce the effect of the above, a method of discharging the refrigerant gas 17B from the exhaust chamber 13 by providing a plurality of through holes in the holding ring 9a (FIG. 2) holding the coil end 9 is also conceivable. Providing a through hole in the ring 9a is adopted because stress may be concentrated in the through hole due to centrifugal force due to high speed operation of the rotor core 8 and mechanical stress of the coil end 9 during operation, resulting in destruction. It is difficult.

An object of the present invention is to provide a cooling device for a rotor coil end of a turbine generator capable of solving the above-mentioned problems and increasing the exhaust gas flow rate of the refrigerant gas flowing into the exhaust chamber. is there.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, according to the present invention, a refrigerant gas which has flowed into an exhaust chamber from a refrigerant gas passage orthogonal to a rotor axis of a coil end of a rotor winding is conventionally used. In addition to the structure of discharging from the exhaust groove at the end of the rotor core in the rotor axial direction, a ventilation hole is provided which communicates with the outer peripheral portion of the rotor core through the inside of the rotor shaft where the exhaust chamber is located. It is also possible to discharge air from the ventilation holes. This makes it possible to increase the flow rate of the refrigerant gas discharged from the exhaust chamber, reduce the flow resistance of the refrigerant gas flow flowing into the exhaust chamber, and reduce the coil ends in the circumferential direction of the rotor shaft. By increasing the cooling efficiency, it is possible to obtain a rotor coil end cooling device capable of suppressing a local temperature increase in which the coil ends are uniformly cooled.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of an essential part showing a structure of a rotor coil end showing an embodiment of the present invention. The same parts as those of the related art will be denoted by the same reference numerals and detailed description thereof will be omitted. FIG. 1 is a sectional view parallel to the rotor shaft 2 including the exhaust chamber 13 of FIG. 3, and also shows a retaining ring 9a for retaining the coil end 9. In FIG. 1, an axial ventilation hole 19 is formed in the shaft center of the rotor shaft 2 in which the exhaust chamber 13 is located from the shaft end to the position of the rotor iron core 8 end, and the outer periphery of the exhaust chamber 13 and the rotor iron core 8 is formed. An exhaust chamber ventilation hole 20 and a rotor core ventilation hole 21 are provided in the radial direction of the rotor shaft 2 and the rotor core 8 so that the parts communicate with the axial ventilation hole 19, respectively.

The formation of the axial ventilation hole 19 provided in the shaft center of the rotor shaft 2 and the rotor core ventilation hole 21 provided in the radial direction of the rotor core 8 is effective in improving the mechanical strength of the rotor. The exhaust chamber is used so as to utilize the machined holes after collecting the test pieces for the mechanical strength test from the radial direction of the rotor shaft 2 and the rotor core 8 which are generally carried out for the investigation. Only the ventilation hole 20 is provided by cutting the rotor shaft 2. Further, in the structure of the cooling device for the rotor coil end 8 on the side of the exciter located on the right side of FIG. 2, the axial center of the rotor shaft 2 in which an exciting conductor for exciting the rotor winding is arranged from an exciting device (not shown) is arranged. The rotor shaft hole 22 provided in the rotor shaft 2 can be used as the axial ventilation hole 19 described above. In this case, the exhaust chamber ventilation hole 20 provided in the rotor shaft 2 should avoid the position where the exciting conductor is arranged. Be installed in

In the rotor coil end cooling device constructed as described above, the rotation of the rotor causes the axial flow fan 3 (FIG. 2) to pressurize the refrigerant gas supply chamber 12 to pass through the through holes 14. Coil end 9 orthogonal to the rotor axis
The refrigerant gas flow 17B flowing in the circumferential direction of the coil end 9 cools the coil end 9 through the zigzag-shaped refrigerant gas passage 16B formed by the insulating material 15 with protrusions having the protrusions 15B contacting both side surfaces of the coil end 9. It flows from an exhaust hole 23 provided in the insulating material partition wall 11 into an exhaust chamber 13 defined adjacent to the supply chamber 12.

Cooling gas 17 flowing into the exhaust chamber 13
B is split into a refrigerant gas flow 171B discharged from the exhaust groove 18 at the end of the rotor core 8 and a refrigerant gas flow 172B flowing into the exhaust chamber ventilation hole 20 provided in the rotor shaft 2. This refrigerant gas flow 172B circulates in the axial ventilation hole 19 formed in the axial center of the rotor shaft 2 and is opened in the outer circumference of the rotor core 8 by the centrifugal force generated by the rotation of the rotor. 21 is discharged to the outside of the rotor core 8 and is discharged to the stator core 7 side together with the refrigerant gas flow 171B.

Therefore, the refrigerant gas flow 17B flowing from the circumferential direction of the coil end 9 into the exhaust chamber 13 is discharged from the conventional exhaust groove 18, and the rotor core 8 is passed through the axial center of the rotor shaft 2. Since we also added a configuration to discharge to the outside of
The discharge amount of the refrigerant gas flow 17B discharged from the inside of the exhaust chamber 13 can be increased, and the exhaust chamber 1 of the refrigerant gas flow 17B can be increased.
The cooling device for the coil end 9 of the rotor can prevent the flow velocity from decreasing due to the flow resistance to the coil 3 and can prevent the temperature difference between the coil ends 9 at the axial ends due to the nonuniform refrigerant gas flow rate. Can be obtained.

[0014]

As described above, according to the present invention, a plurality of refrigerant gas supply chambers and exhaust chambers are provided in the circumferential direction of the rotor shaft, and the refrigerant gas is pressurized from the supply chambers in the rotor shaft direction and In a cooling device that cools a rotor end coil by diverting and circulating a refrigerant gas in a direction orthogonal to the rotor axis, from a refrigerant gas passage orthogonal to the rotor axis of the coil end of the rotor coil to an exhaust chamber. The circulating refrigerant gas is also discharged from the ventilation holes communicating with the outer peripheral portion of the rotor core through the inside of the rotor shaft. This makes it possible to increase the discharge amount of the cooling gas discharged from the exhaust chamber, reduce the flow resistance of the refrigerant gas flow flowing into the exhaust chamber, and reduce the coil ends in the circumferential direction of the rotor shaft. Since it is possible to improve the cooling capacity, it is possible to obtain a cooling device in which there is no temperature difference between the coil ends and in which the temperature rise is further reduced, and the allowable energizing capacity of the rotor coil can be increased compared to the conventional one. It is possible to economically provide a smaller turbine generator.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an essential part showing a structure of a rotor coil end showing an embodiment of the present invention.

FIG. 2 is a main part sub-sectional view showing a turbine generator for explaining the present invention.

FIG. 3 is a perspective sectional view showing a cooling device for a coil end of a rotor winding of a conventional turbine generator.

FIG. 4 is a perspective view showing a main part of a cooling device that constitutes a refrigerant gas passage of a conventional coil end.

[Explanation of symbols]

 1 Stator winding coil end 2 Rotor shaft 6 Refrigerant gas 6A Refrigerant gas flow 6B Refrigerant gas flow 8 Rotor iron core 11 Insulating material partition wall 12 Refrigerant gas supply chamber 13 Exhaust chamber 14 Through hole 15 Insulating material with protrusion 16A Refrigerant gas Passage 16B Refrigerant gas passage 17A Refrigerant gas flow 17B Refrigerant gas flow 171B Refrigerant gas flow 172B Refrigerant gas flow 18 Exhaust groove 19 Axial ventilation hole 20 Exhaust chamber ventilation hole 21 Rotor core ventilation hole 22 Rotor shaft hole

Claims (1)

[Claims] 1. A refrigerant gas from a cooler is introduced into the machine by a fan provided at a rotor shaft end of a turbine generator,
A cooling device for cooling a coil end of a rotor winding composed of a plurality of saddle-shaped coils wound around a rotor iron core in a multi-annular shape, wherein a space between the coil end and the rotor shaft end is surrounded by its circumference. Insulating material partition wall divided into a plurality of refrigerant gas supply chambers and exhaust chambers, and a zigzag-shaped refrigerant interposed between the coil ends to maintain a gap therebetween. An insulating material with a projection forming a gas passage, and a through hole formed in a key part of the insulating material partition wall,
The refrigerant gas passage through which the refrigerant gas from the refrigerant gas supply chamber that flows in through this through hole flows, the refrigerant gas flowing in a zigzag shape along the surfaces respectively parallel to the rotor axis of the coil end in the rotor core. Two systems: a system that discharges the gas through the formed ventilation hole to the outside and a system that discharges the refrigerant gas that flows in a zigzag shape along the plane orthogonal to the rotor axis of the coil end to the outside through the exhaust chamber. In a rotor coil end cooling device of a turbine generator configured from, an axial ventilation hole extending in the axial direction is provided inside the rotor shaft, a rotor shaft in which the exhaust chamber is located, and a rotor core adjacent to the rotor shaft. An exhaust chamber ventilation hole communicating with the axial ventilation hole penetrating in the respective radial directions and a rotor core ventilation hole, and the refrigerant gas flowing into the exhaust chamber is axially communicated from the exhaust chamber ventilation hole. Holes and rotor core vents and the rotor coil end cooling system of the turbine generator, characterized in that made it possible to discharge to the outside of the rotor core through.