KR101091893B1 - Turbo generator apparatus and fuel cell system with the same - Google Patents

Abstract

According to the invention, the housing; A compressor scroll and a turbine scroll extending sequentially from the housing; A tie shaft extending and rotatably installed through the housing, the compressor scroll, and the turbine scroll; A rotor coupled to the tie shaft in the housing; An impeller coupled to the tie shaft corresponding to the compressor scroll; A turbine wheel coupled to the tie shaft corresponding to the turbine scroll; A stator winding part installed inside the housing corresponding to the rotor; First and second radial bearings respectively rotatably holding said tie shaft at a position at said first end of said tie shaft spaced from said impeller and at a position proximate to said impeller; A thrust disk coupled to the first end of the tie shaft; A turbogenerator device having first and second thrust bearings disposed at the front and rear of the thrust disc, respectively, and a fuel cell system having the same are provided.

Description

Turbo generator apparatus and fuel cell system having the same {Turbo generator apparatus and fuel cell system with the same}

1 is a schematic cross-sectional view of a turbogenerator device according to the prior art.

2 is a schematic cross-sectional view of a turbogenerator device according to an embodiment of the present invention.

3 is an enlarged cross-sectional view of a portion of the turbo generator device shown in FIG. 2 in the longitudinal direction.

4 is an enlarged cross-sectional view showing a state where the thrust disk and the bearings are assembled to each other at the front portion of the tie shaft.

5 shows the thrust disk and bearings in an exploded state.

6 is a schematic structural diagram of a fuel cell system having a turbo generator device.

<Brief Description of Major Codes in Drawings>

31.Tie Shaft 32.Rotor

33. Impeller 34. Turbine Wheel

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbogenerator device and a fuel cell system having the same, and more particularly, to a turbogenerator system that is easy to be assembled and disassembled and excellent in cooling efficiency of a bearing, and a fuel cell device including the same.

In general, a turbogenerator device is a device in which a compressor, a gas turbine, and a motor-generator are coaxially coupled to each other, and the rotational force of the compressor and the motor-generator by rotating the gas turbine with a combustion gas generated by burning compressed air and fuel. To get the device. Specifically, the compressed air is supplied to the combustor by the operation of the compressor and the fuel is injected to burn the fuel, and the gas turbine is rotated by using the high-temperature and high-pressure discharge gas generated by the combustion. Compressors and motor-generators on coaxial lines can be rotated to obtain air compression and power. Such a turbogenerator device may be applied as a small generator, and recently, may be configured as a fuel cell system combined with a fuel cell.

Shown in FIG. 1 is a schematic cross-sectional view of a turbogenerator device according to the prior art, which is disclosed in US Pat. No. 6,198,174.

Referring to the drawings, it is shown that the rotor 12 of the motor-generator, the impeller 13 of the compressor, and the turbine wheel 14 of the gas turbine are coaxially coupled by the tie shaft 11. The rotor 12 of the motor-generator is a permanent magnet, and a stator winding 22 is provided around the rotor 12 of the motor-generator. Therefore, when the rotor 12 rotates, induced electromotive force may be generated in the stator winding part 22. A scroll 15 of the compressor is formed on the outer circumference of the impeller 13, and the air flowing from the air inlet 20 is compressed by the rotation of the impeller 13 and flows out through the scroll 15. Compressed air flowing out through the scroll 15 is supplied to a combustor, not shown, to combust with fuel.

The turbine scroll 16 of a gas turbine is formed in the outer periphery of the turbine wheel 14. The combustion gas of high temperature and high pressure generated by combustion of fuel in a combustor (not shown) flows into the turbine scroll 16, and the turbine wheel 14 may be rotated by the action of the combustion gas. Rotation of the turbine wheel 14 causes the impeller 13 and the rotor 12 to rotate through the tie shaft 11. The combustion gas expanded in the turbine scroll 16 is discharged through an exhaust diffuser 21.

In the turbogenerator device as shown, the rotatably holding the tie shaft 11 comprises airfoil bearings 17, 18 installed proximate to the impeller 13 in the middle of the path of the tie shaft 11; Another air foil bearing 19 located at one end of the tie shaft 11. In particular, the air foil bearing 17 serves as a thrust bearing.

The apparatus of the turbogenerator as described above has the following problems with respect to the bearing structure. First, since the air foil bearing 18 exists between the impeller 13 and the rotor 68, the length of the whole apparatus tends to be unnecessarily long. In addition, the assembly and disassembly of the air foil bearing 18 has a problem in that disassembly and assembly are difficult because the disassembly structure has a laminated structure involving assembly and disassembly of components other than the air foil bearing.

On the other hand, the arrangement of the air foil bearing 18 serving as the thrust bearing in close proximity to the impeller 13 and the turbine wheel 14 makes the thermal management of the bearing difficult. That is, a high-temperature atmosphere is achieved in the vicinity of the impeller 13 and the turbine wheel 14, and furthermore, since a lot of heat is generated in the thrust bearing itself, it is possible to more easily reach the limit situation of the action of the bearing. Therefore, there is a problem that the replacement time of the air foil bearing 18 and the other parts is accelerated.

 The present invention has been made to solve the above problems, an object of the present invention to provide an improved turbogenerator device.

Another object of the present invention is to provide a turbogenerator device which ensures the life of a bearing and facilitates disassembly and assembly at the time of bearing replacement.

It is a further object of the present invention to provide a turbogenerator device with a thrust bearing which is improved separately.

Another object of the present invention is to provide a fuel cell system with an improved turbogenerator device.

In order to achieve the above object, according to the present invention,

A housing;

A compressor scroll and a turbine scroll extending sequentially from the housing;

A tie shaft extending and rotatably installed through the housing, the compressor scroll, and the turbine scroll;

A rotor coupled to the tie shaft in the housing;

An impeller coupled to the tie shaft corresponding to the compressor scroll;

A turbine wheel coupled to the tie shaft corresponding to the turbine scroll;

A stator winding part installed inside the housing corresponding to the rotor;

First and second radial bearings respectively rotatably holding said tie shaft at a position at a first end of said tie shaft spaced from said impeller and at a position proximate to said impeller;

A thrust disk coupled to the first end of the tie shaft;

Provided are a turbogenerator device including first and second thrust bearings disposed in front and rear of the thrust disc, respectively.

According to one feature of the invention, the first radial bearing and the second thrust bearing are integrally formed.

According to another feature of the invention, the first and second radial bearings and the first and second thrust bearings are air foil bearings.

Further, according to the present invention, a rotor disposed in a housing, a stator winding portion, an impeller constituting a compressor, and a turbine wheel constituting a gas turbine are rotatably installed on a coaxial tie shaft. And the tie shaft comprises first and second radial bearings disposed at positions of a first end of the tie shaft spaced apart from the impeller and at positions close to the impeller, respectively, and a first of the tie shaft. A thrust disk coupled to an end, and a turbo generator rotatably held by first and second thrust bearings disposed respectively in front of and behind the thrust disk;

A fuel cell supplied with compressed air from the compressor;

A combustor configured to combust the heated air in the fuel cell and the fuel supplied from the fuel supply to generate a combustion gas of high temperature and high pressure;

A battery for supplying or charged with the current generated in the motor-generator to the motor-generator;

A start signal applying unit for applying a start signal for starting supply of current from the battery to the motor-generator;

A switch unit for converting a direction of current between the battery and the motor-generator;

A control unit for controlling an operation of changing the direction of the current in the switch unit;

Provided is a fuel cell system comprising: a sensor unit for detecting an operating state of the turbo generator and transmitting operating state information to the control unit.

Hereinafter, the present invention will be described in more detail with reference to an embodiment shown in the accompanying drawings.

2 is a schematic cross-sectional view of a turbogenerator device according to an embodiment of the present invention, and FIG. 3 is an enlarged cross-sectional view of a portion of the turbogenerator device shown in FIG. 2 in the longitudinal direction. .

Referring to FIG. 2, the turbogenerator according to the present invention includes a housing 41, an air inlet 50 installed on the first side of the housing 41, and the housing on the second side of the housing 41. Compressor scroll 35 extended to 41, turbine scroll 36 provided in close proximity to compressor scroll 35, housing 41, compressor scroll 35, and turbine scroll 36. A tie shaft 31 extending and rotatably installed, a rotor 32 coupled to the tie shaft 31 in the housing 41, and the tie shaft (31) corresponding to the compressor scroll 35. An impeller 33 provided at 31, a turbine wheel 34 coupled to the tie shaft 31 in correspondence with the turbine scroll 36, and an inner side of the housing 31 in correspondence with the rotor 32. It includes a stator winding portion 42 installed in. The rotor 32 is typically made of a permanent magnet, and the rotor 32 is substantially formed integrally with the tie shaft 31. The stator winding part 42 is made by winding a conductive coil. When the rotor 32 rotates inside the stator winding part 42 by the rotational force of the turbine wheel 34, a current is generated in the conductive coil forming the stator winding part 42, thereby acting as a generator. On the contrary, when an external current is applied to the stator winding part 42, it can act as a motor that can rotate the rotor 32. As a result, the impeller 33 and the turbine wheel 34 are rotated so that the turbogenerator is rotated. Can be activated.                     

Referring to FIG. 3, according to one feature of the invention, the first radial bearing 48 rotatably holding the tie shaft 31 at the first end of the tie shaft 31 and the impeller 33 A second radial bearing 45 is provided for rotatably holding the tie shaft 31 in a position proximate to. Preferably, the first and second radial bearings 48 and 45 are air foil bearings. As can be seen from the figure, the tie shaft 31 is formed substantially integrally with the rotor 32, so that the tie shaft 31 having a small cross-sectional diameter at both ends is provided with the rotor 32. In the part close to), the cross-sectional diameter is gradually increased. Accordingly, the first and second rotary bearings 48 and 45 may be disposed to correspond to the portion of the tie shaft 31 having an increased diameter, thereby keeping the tie shaft 31 rotatable.

According to another feature of the present invention, the thrust disk 49 coupled to the first end of the tie shaft 31 and the first thrust bearing 46 disposed in front of the thrust disk 49. And a second thrust bearing 47 disposed behind the thrust disc 49. The first thrust bearing 46 is installed by its outer edge being fixed to the inner surface of the housing 41, and the second thrust bearing 47 is substantially integral with the first radial bearing 48. It is preferred to be formed. The outer edge of the second thrust bearing 47 is also fixed to the inner surface of the housing 41. The first and second thrust bearings 46 and 47 can be configured as known air foil bearings.

4 is an enlarged cross-sectional view of a state in which the thrust disk and the bearings are assembled to each other at the front portion of the tie shaft, and FIG. 5 shows the thrust disk and the bearings in an exploded state.

Referring to FIG. 4, the thrust disc 49 is coupled to the front of the tie shaft 31, and the fastener 31 is provided at the end of the tie shaft 31 to fix the thrust disc 49 in place. Is fixed. The thrust disc 49 maintains forward and rearward axial thrusts transmitted through the tie shaft 31 through the first thrust bearing 46 and the second thrust bearing 47. Can be. 5, the individual structures of each bearing and thrust disc can be understood.

The operation of the above-described turbo generator will be described schematically with reference to the drawings.

Referring to FIG. 2, outside air may be introduced into the housing 41 through the air inlet 50 installed at the first side of the housing 41. In this case, an air filter (not shown) may be installed in front of the air inlet 50, and air may be filtered by the action of the air filter.

Since the outside air flowing into the housing 41 is a relatively low temperature fluid, it can act to cool the bearings while the air flows toward the compressor scroll 35 installed on the other side of the housing 41. That is, the air flowing into the housing 41 first cools the first thrust bearing 46, the second thrust bearing 47, and the first radial bearing 48, and then the impeller 33. It is possible to cool the second radial bearing 45 disposed in close proximity to).

The introduced air flows into the compressor scroll 35 in a high pressure state after receiving the compression action by the impeller 33. Compressed air may be supplied to other external components through a flow path connected to the compressor scroll 35. In the case of US Pat. No. 6,198,174 mentioned above, heat exchange was carried out with the hot exhaust gas exiting the gas turbine using high pressure air compressed by a compressor. In the present invention, in particular, the air compressed by the compressor will be used as the working fluid of the fuel cell (not shown), which will be described in more detail later.

The air compressed by the compressor is combusted with fuel in a combustor (not shown) after it is used for heat exchange or for the reaction of the fuel cell, whereby the high temperature and high pressure combustion gas generated is produced by the turbine scroll of the gas turbine. Flows into). The combustion gas entering the turbine scroll 36 rotates the turbine wheel 34 and is then discharged to the outside through the discharge diffuser 36.

6 shows a schematic diagram of a fuel cell system having a turbogenerator device as described above.

Referring to the drawings, the fuel cell system including the turbo generator according to the present invention is disposed in the housing 41 having an air inlet portion on one side, and the rotor 32 and the stator winding portion 42 constituting the motor generator. ), A turbo generator (61) formed by rotatably installing an impeller (33) constituting the compressor and a turbine wheel (34) constituting the gas turbine on the tie shaft (31) of the same axis; An air filter (69) disposed to supply filtered air to an air inlet of the housing (41); A fuel cell 62 to which air compressed by the compressor is supplied; A combustor 63 to which air heated in the fuel cell 62 is supplied; A fuel supplier (64) for supplying fuel to the combustor (63) for discharging the combustion gas of high temperature and high pressure to the gas turbine; A battery 74 for supplying the motor-generator charged or charged with the current generated in the motor-generator; A start signal applying unit (73) for applying a start signal for starting supply of current from the battery (74) to the motor-generator; A switch unit (72) for converting a direction of current between the battery (74) and the motor-generator; A control unit (75) for controlling the direction change operation of the current in the switch unit (72); The sensor unit 76 detects an operating state of the turbo generator 61 and transmits operating state information to the control unit 75.

The air filtered through the air filter 69 is supplied to the compressor through the housing 41, and subsequently heated in the fuel cell 62, burned with fuel in the combustor 63, and supplied to the gas turbine After rotating the turbine wheel 34 is discharged to the outside.

As is well known, the fuel cell 62 is a device that obtains heat and electricity simultaneously using methanol as a fuel, or obtains power through a reaction of hydrogen and oxygen. Since the redox reaction occurring in the fuel cell is an exothermic reaction, the compressed air supplied from the compressor can be heated by the heat generated from such a redox reaction. Thereby, the compressed air is discharged as a working fluid of high temperature and high pressure. However, although the working fluid discharged from the fuel cell 63 is in a state of high temperature and high pressure, since the temperature and pressure are not sufficient to drive the gas turbine 34, the high temperature and high pressure working fluid is the combustor 170. ) Is burned together with the fuel supplied from the fuel supply 64 to raise the pressure and temperature.

Combustion gas generated by burning fuel in the combustor 63 flows into the gas turbine to rotate the turbine wheel 34. Rotation of the turbine wheel 34 rotates the impeller 33 of the comp fp and the rotor 42 of the motor-generator together through the tie shaft 31. This generates electricity in the motor-generator. The current may be applied in the direction of charging the battery 74 according to the switch operation of the switching unit 72.

Reference numeral 65 denotes that some of the compressed air in the compressor enters the gas turbine and is used for cooling the gas turbine. Some of the air compressed by the impeller 33 in the compressor can be supplied to the gas turbine and used to cool the heat generated in the gas turbine. For this purpose, gas turbines may be provided with a known air jacket through which cooling air can be circulated.

On the other hand, in the fuel cell system according to the present invention as described above, the air inlet is formed on one side of the housing 41 of the turbo generator 61, so that the air flowing into the compressor of the turbo generator 61 is the housing ( Supplied through 41). Thus, cooling to the bearing supporting the tie shaft 32 can be effected effectively.

The turbogenerator device and the fuel cell system having the same according to the present invention have the advantage that the radial bearing for rotatably holding the tie shaft of the turbogenerator and the thrust bearing can be easily disassembled and assembled. In addition, since the thrust bearing and the thrust disc are disposed at a position spaced apart from the high temperature part of the compressor and the gas turbine, the possibility of deterioration due to heat is reduced and thereby the service life is extended. In addition, since the overall length of the thrust bearing can be reduced, the turbogenerator device can be further miniaturized, and the workability is greatly improved.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, this is only illustrative, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Could be. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

Claims (8)

A housing having a shape in which air therein does not flow outward in a radial direction of the central axis; An air inlet formed on the first side of the housing; An impeller installed in the housing and a turbine wheel; A shaft penetrating the impeller and the turbine wheel and rotatably installed; First and second radial bearings respectively rotatably holding the shaft at a position at a first end of the shaft spaced from the impeller and at a position proximate to the impeller; A thrust disk coupled to the first end of the shaft; And And first and second thrust bearings disposed at the front and the rear of the thrust disc, respectively. Air flowing into the housing is sequentially introduced while contacting the air inlet, the first thrust bearing, the thrust disc, the second thrust bearing, and the first radial bearing, and into the housing. The introduced air moves in contact with the second radial bearing and flows into the impeller. The method of claim 1, The housing further includes a compressor scroll and a turbine scroll, The impeller is installed corresponding to the compressor scroll; And the turbine wheel is installed corresponding to the turbine scroll. The method of claim 1, A rotor rotatably installed on the shaft; And a stator winding part installed in the housing in correspondence with the rotor. delete The method of claim 1, And the first radial bearing and the second thrust bearing are integrally formed. The method of claim 1, And the first thrust bearing and the second thrust bearing are air foil bearings. A housing having a shape in which internal air does not flow out to the outside in a radial direction of the central axis, an air inlet formed on the first side of the housing, a rotor and a stator winding part disposed in the housing and constituting a motor-generator; The impeller constituting the compressor and the turbine wheel constituting the gas turbine are rotatably installed on the shaft of the same axis, the shaft being located at a position of the first end of the shaft spaced apart from the impeller and close to the impeller. First and second radial bearings disposed respectively in position, thrust disks coupled to the first end of the shaft, first and second thrusts respectively disposed in front and rear of the thrust disks. A turbogenerator device rotatably held by the bearing; A fuel cell supplied with compressed air from the compressor; A combustor configured to combust the heated air in the fuel cell and the fuel supplied from the fuel supply to generate a combustion gas of high temperature and high pressure; A battery for supplying or charged with the current generated in the motor-generator to the motor-generator; A start signal applying unit for applying a start signal for starting supply of current from the battery to the motor-generator; A switch unit for converting a direction of current between the battery and the motor-generator; A control unit for controlling an operation of changing the direction of the current in the switch unit; And a sensor unit for detecting an operating state of the turbogenerator device and transferring operating state information to the control unit. The turbo generator device may be introduced while the air flowing into the housing sequentially contacts the air inlet, the first thrust bearing, the thrust disc, the second thrust bearing, and the first radial bearing. And the air introduced into the housing sequentially moves while contacting the stator winding part and the second radial bearing to flow into the impeller. The method of claim 7, wherein And the first and second radial bearings and the first and second thrust bearings are air foil bearings.

Images