KR101634875B1 - Micro gas turbine with bearing cooling part - Google Patents

Abstract

The present invention relates to an ultra miniature gas turbine having a bearing cooling part, wherein the ultra miniature gas turbine having a bearing cooling part according to the present invention comprises: a compressor mounted on a shaft and supplied with gas from outside to generate a high pressure gas; A combustor for receiving a high-pressure gas from the compressor to generate a high-temperature high-pressure gas; A turbine mounted on the shaft and generating power by receiving energy from a high temperature and high pressure gas supplied from the combustor; A bearing mounted on the shaft and supporting a load applied to the shaft using a high-pressure gas generated from the compressor; A bearing housing enclosing the shaft and spaced apart from the shaft by a predetermined distance to form a flow path through which the high-pressure gas flows; And a bearing cooling unit for cooling a part of the high-pressure gas generated from the compressor and moving toward the combustor, to supply the cooled gas to the flow path side. Thus, the air bearing mounted on the shaft is driven by the high-pressure gas passed through the compressor, and the temperature rise of the high-pressure gas is prevented by mixing the external air and the high-pressure gas or by heat exchange, And a bearing cooling section capable of cooling the gas turbine.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a micro gas turbine having a bearing cooling part,

The present invention relates to an ultra miniature gas turbine having a bearing cooling unit, and more particularly, to an ultra miniature gas turbine having a bearing cooling unit, which drives an air bearing mounted on a shaft using a high pressure gas passed through a compressor, And a bearing cooling section capable of preventing overheat damage of the air bearing by preventing the air bearing from overheating.

Recently, the need for a portable power source that can be used for a long time unlike a large-scale centralized power plant has greatly increased throughout the industry and society. The power sources include fuel cells and lithium ion rechargeable batteries. Particularly, the miniaturized gas turbine has advantages such as low initial investment cost, small size and light weight compared with reciprocating engine having the same output, and simple structure and low maintenance cost.

Lithium secondary batteries are mainly used in portable devices currently in use. However, typical commercial secondary batteries have a disadvantage in that they are short in continuous use time and take a long time to charge, and the energy density is close to the theoretical limit, so that the performance of portable electronic devices can not be solved by conventional secondary batteries . Recently, as the products requiring portable power source such as pet robots, humanoid robots, and military robots are in commercialization phase, the need and urgency of a new micro power feeder is increasing. The micro power generation system is basically required to have higher energy density than the existing power source, and it is assured that it is necessary to develop the power generation system. Ultra micro gas turbine (UMGT) is attracting attention as a power generation device with high output and energy density.

Generally, a micro gas turbine has a structure in which a generator, a compressor and a turbine are connected to a shaft, and a generator portion and a compressor and a turbine shaft are connected by a coupling. These shafts are equipped with bearings to support loads caused by rotation of the compressor and the turbine.

In a micro gas turbine, it is difficult to provide a structure for supplying air to float the shaft between the air bearing and the shaft when the air bearing is used. Even if air inside the gas turbine is supplied, the temperature of the air is high. There is a problem.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to solve the problems of the prior art described above and to provide a method of operating an air bearing mounted on a shaft using a high pressure gas passed through a compressor, And a bearing cooling section that prevents overheating of the air bearing by preventing a temperature rise of the gas.

According to the present invention, the above object is achieved by a compressor comprising: a compressor mounted on a shaft and generating a high-pressure gas by being supplied with gas from the outside; A combustor for receiving a high-pressure gas from the compressor to generate a high-temperature high-pressure gas; A turbine mounted on the shaft and generating power by receiving energy from a high temperature and high pressure gas supplied from the combustor; A bearing mounted on the shaft and supporting a load applied to the shaft using a high-pressure gas generated from the compressor; A bearing housing enclosing the shaft and spaced apart from the shaft by a predetermined distance to form a flow path through which the high-pressure gas flows; And a bearing cooling part for cooling a part of the high pressure gas generated from the compressor and moving to the combustor side and supplying the cooled part to the flow path side.

Here, it is preferable that a part of the high-pressure gas generated from the compressor is supplied to the flow path and the rest moves to the combustor side, and a part of the high-pressure gas moving to the combustor side is supplied to the bearing cooling unit.

Here, the bearing cooling unit may include: a first pipe through which the high-pressure gas flows and one end communicates with the flow path; And a second pipe arranged so as to surround the first pipe so that the high-pressure gas and the outside air are mixed and supplied to the flow path side, and one region communicates with the first pipe Do.

Here, the bearing cooling unit may include: a first pipe through which the high-pressure gas flows and one end communicates with the flow path; And a second pipe arranged to surround the first pipe and to receive external air so that the high-pressure gas is cooled.

Here, the bearing cooling unit may include: a first pipe through which the high-pressure gas flows and one end communicates with the flow path; And a heat insulating material disposed to surround the first tube.

Here, the bearing cooling portion is preferably installed at a half of the longitudinal direction of the shaft.

Here, the bearing cooling unit may be installed through the bearing housing.

According to the present invention, an air bearing is provided in a shaft on which a compressor and a turbine are mounted, so that a small-sized gas turbine having a bearing cooling portion which is lifted and rotated in a frictionless state without requiring a separate lubricating oil, / RTI >

Further, since the bearing utilizes the high-pressure gas that has passed through the compressor, there is provided an ultra-small gas turbine having a bearing cooling section having a compact configuration.

Further, since the outside air is used to cool a part of the air that has passed through the compressor or to prevent the temperature from rising, it is possible to prevent the bearing from being overheated.

In addition, since the bearing cooling portion is provided at the middle point of the shaft, the air can be uniformly supplied to the compressor and the turbine side so that the balance can be balanced.

1 is a schematic cross-sectional view of a micro gas turbine having a bearing cooling unit according to a first embodiment of the present invention,
FIG. 2 is a view schematically showing a movement path of a high-pressure gas passing through a compressor of an ultra-small gas turbine having a bearing cooling unit of FIG. 1,
3 is a view illustrating a bearing cooling unit of a micro gas turbine having the bearing cooling unit of FIG. 1,
4 is a view illustrating a bearing cooling unit of a micro gas turbine having a bearing cooling unit according to a second embodiment of the present invention,
5 is a view illustrating a bearing cooling unit of a micro gas turbine having a bearing cooling unit according to a third embodiment of the present invention.

Prior to the description, components having the same configuration are denoted by the same reference numerals as those in the first embodiment. In other embodiments, configurations different from those of the first embodiment will be described do.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a micro gas turbine including a bearing cooling unit according to a first embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The micro gas turbine having the bearing cooling unit according to the present embodiment drives an air bearing mounted on a shaft by using a high pressure gas passed through a compressor. By mixing the mixing of external air and high pressure gas to cool the high pressure gas, And a bearing cooling section capable of preventing overheat damage.

1 is a schematic cross-sectional view of a micro gas turbine having a bearing cooling unit according to a first embodiment of the present invention. 1, an ultra-small gas turbine 100 having a bearing cooling unit according to a first embodiment of the present invention includes a shaft 110, a compressor 120 mounted on one end of the shaft 110, A turbine 140 that receives high-temperature and high-pressure gas from the combustor 130; a bearing 150 that is mounted on the shaft 110; And a bearing cooling unit 170 and a bearing housing 160 spaced apart from each other by a predetermined distance.

The shaft 110 is configured to transmit power generated by the rotation of the rotating body such as the turbine 140. A compressor 120 and a turbine 140 are mounted on both ends of the shaft 110 and a bearing 150 is mounted on the shaft 110 to support a load.

The compressor 120 is configured to generate a high-pressure gas by receiving gas from the outside. The compressor 120 is initially driven by a motor (not shown), and rotates to compress gas supplied from the outside to generate a high-pressure gas. At this time, the compressed gas supplied from the outside to the compressor 120 has a temperature of about 200 ° C.

On the other hand, the high-pressure gas introduced from the outside and passed through the compressor 120 is partially supplied to the flow path 161 and the remainder is moved to the combustor 130 side. A part of the high-pressure gas moving toward the combustor 130 flows into the bearing cooling unit 170 side and then is cooled and supplied to the flow path 161 side.

The combustor 130 is configured to generate high-temperature and high-pressure gas from the high-pressure gas supplied from the compressor 120. The combustor 130 is provided in a hollow shape, and a fuel supply pipe (not shown) for supplying fuel is communicated, and an igniter is installed. That is, the combustor 130 is configured to generate high-temperature and high-pressure gas by igniting a mixture gas mixed with high-pressure gas and fuel supplied from the compressor 120 through an igniter and burning it.

When the high-pressure gas supplied from the compressor 120 is combusted in the combustor 130, the temperature of the combustor 130 is very high. In this embodiment, the temperature of the combustor 130 is about 1000 ° C.

The turbine 140 is configured to generate power by receiving energy from high-temperature and high-pressure gas generated in the combustor 130. The turbine 140 is installed in the shaft 110 together with the compressor 120.

The bearing 150 is configured to support a load applied to the shaft 110 by the rotation of the compressor 120 and the turbine 140. The bearing 150 is provided with an air bearing. Air bearings support the shaft using an automatically generated fluid dynamic pressure between a high-speed rotating disc and a foil-like structure.

FIG. 2 is a view schematically showing a moving path of a high-pressure gas that has passed through a compressor of a micro gas turbine having a bearing cooling unit of FIG. 1; Referring to FIG. 2, in this embodiment, the bearing 150 includes compressed air that has passed through the compressor 120 and has flowed into the flow path 161, and air that has passed through the compressor 120 and moves to the combustor 130 side Compressed air introduced into the oil passage 161 after flowing into the bearing cooling section 170 is used. At this time, since the compressed air flowing into the bearing cooling unit 170 is cooled by the outside air, the overheat damage due to the temperature rise of the bearing 150 is prevented.

On the other hand, a compressed air film is formed between the bearing (150) and the shaft (110) while the shaft (110) rotates at a high speed and is lifted and rotated at a high speed without friction. In addition, the compressed air introduced into the flow path 131 not only supports the shaft 110 but also the bearing 140 is cooled to prevent overheat damage.

The bearing housing 160 is configured such that a bearing 170 is received therein and is spaced apart from the shaft 110 by a predetermined distance. The spacing space between the shaft 110 and the bearing housing 160 serves as a flow passage 161 through which the high-pressure gas passed through the compressor 120 flows. That is, the bearing housing 160 accommodates the bearing 150 and is spaced apart from the shaft 110 by a predetermined distance to form a flow path 161 for floating the shaft 110 from the bearing 150.

3 is a view illustrating a bearing cooling unit of a micro gas turbine including the bearing cooling unit of FIG. The bearing cooling unit 170 cools a part of the compressed air moving to the combustor 130 side through the compressor 120 so as to be supplied to the flow path 161. The operation of the bearing 150 and the cooling of the bearing 150 . Referring to FIG. 3, the bearing cooling unit 170 is provided in a double pipe shape including a first pipe 171 and a second pipe 172.

The first pipe 171 is a path through which a part of the compressed air moving through the compressor 120 to the combustor 130 moves toward the flow path 161. The first pipe 171 passes through the compressor 120 and flows toward the combustor 130 And the other end is provided so as to communicate with the flow path 161.

The second pipe 172 is configured to cool the compressed air moving along the first pipe 171 and surrounds the first pipe 171. The second pipe 172 is provided with an external air supply unit 172a, Outside air is introduced. The first pipe 171 and the second pipe 172 are provided to communicate with each other in the vicinity of the oil line 161 so that the compressed air and the external air are mixed with each other. The temperature of the outside air is relatively low as compared with the temperature of the compressed air that has passed through the compressor 120, so that the temperature of the mixed air is lowered, and the compressed air is supplied to the flow path 161.

The compressed air flowing into the first pipe 171 is mixed with the outside air in the second pipe 172 and is cooled and supplied to the oil passage 161 of the bearing 150 and the shaft 110, Float to support the load. In addition, the compressed air is cooled, thereby preventing the bearing 150 from being overheated.

Meanwhile, the bearing cooling unit 170 is preferably installed at a half point in the longitudinal direction of the shaft 110, that is, at an intermediate point. The cooled compressed air supplied to the oil passage 161 through the bearing cooling unit 170 moves toward the compressor 120 and the turbine 140 and is installed at the midpoint of the shaft 110 to supply a uniform amount , The thrust force applied to the shaft 110 and the uniform cooling are possible.

Next, a micro gas turbine having a bearing cooling unit according to a second embodiment of the present invention will be described.

The micro gas turbine having the bearing cooling unit according to the present embodiment drives an air bearing mounted on a shaft using a high pressure gas passed through a compressor. The air bearing is cooled by heat exchange between external air and high pressure gas, And a bearing cooling section capable of preventing overheat damage of the air bearing by preventing the air bearing from being overheated.

The micro gas turbine including the bearing cooling unit according to the second embodiment of the present invention includes a shaft 110, a compressor 120 mounted on one end of the shaft 110, and a high- A turbine 140 that receives high temperature and high pressure gas from the combustor 130, a bearing 150 that is mounted to the shaft 110, and a shaft 150 that is disposed to surround the shaft 110, And includes a bearing housing 160 and a bearing cooling portion 270 which are spaced apart from each other. The shaft 110, the compressor 120, the combustor 130, the turbine 140, the bearing 150, and the bearing housing 160 are the same as those of the first embodiment,

4 is a view illustrating a bearing cooling unit of a micro gas turbine having a bearing cooling unit according to a second embodiment of the present invention. The bearing cooling unit 270 cools a portion of the compressed air moving through the compressor 120 to the combustor 130 side and supplies the compressed air to the flow path 161. By operating the bearing 150 and cooling the bearing 150 . Referring to FIG. 4, the bearing cooling unit 270 is provided in a double pipe shape including a first pipe 171 and a second pipe 172. In this embodiment, the bearing cooling unit 270 differs from the first embodiment in that compressed air is cooled through heat exchange.

The first pipe 271 is a path through which a portion of the compressed air traveling through the compressor 120 to the combustor 130 moves toward the flow path 161. One end of the compressed air passes through the compressor 120 and flows toward the combustor 130 side And the other end is provided so as to communicate with the flow path 161.

The second pipe 272 is configured to cool the compressed air moving along the first pipe 271 and surrounds the first pipe 271. The second pipe 272 is provided with an external air supply unit 172a, Outside air is introduced. The compressed air in the first pipe 271 is heat-exchanged with the external air flowing in the second pipe 272 and cooled to be supplied to the flow path 161.

The compressed air introduced into the first pipe 271 is cooled through heat exchange with the external air inside the second pipe 272 and supplied to the oil passage 161 of the bearing 150 and the shaft 110, To support the load. In addition, the compressed air is cooled, thereby preventing the bearing 150 from being overheated.

Next, a micro gas turbine having a bearing cooling unit according to a third embodiment of the present invention will be described.

The micro gas turbine including the bearing cooling unit according to the present embodiment drives an air bearing mounted on a shaft by using a high pressure gas passed through a compressor. By protecting the high pressure gas from heat, the temperature of the high pressure gas is prevented from rising, The present invention relates to an ultra-small gas turbine having a bearing cooling section capable of preventing damage.

A micro gas turbine having a bearing cooling unit according to a third embodiment of the present invention includes a shaft 110, a compressor 120 mounted on one end of the shaft 110, a high- A turbine 140 that receives high temperature and high pressure gas from the combustor 130, a bearing 150 that is mounted to the shaft 110, and a shaft 150 that is disposed to surround the shaft 110, And includes a bearing housing 160 and a bearing cooling portion 370 which are spaced apart from each other. The shaft 110, the compressor 120, the combustor 130, the turbine 140, the bearing 150, and the bearing housing 160 are the same as those of the first embodiment,

5 is a view illustrating a bearing cooling unit of a micro gas turbine having a bearing cooling unit according to a third embodiment of the present invention. The bearing cooling unit 370 is a configuration for operating the bearing 150 by preventing the temperature of the compressed air moving through the compressor 120 and moving toward the combustor 130 from being raised and supplied to the flow path 161 side. Referring to FIG. 5, the bearing cooling unit 370 includes a first pipe 171 and a heat insulating material 372 disposed to surround the outer circumferential surface of the first pipe 171. In this embodiment, the bearing cooling portion 370 is different from the above-described embodiments in that the bearing cooling portion 370 is thermally insulated through the heat insulating material 372 to prevent the temperature rise.

The first pipe 171 is a path through which a part of the compressed air moving through the compressor 120 to the combustor 130 moves toward the flow path 161. The first pipe 171 passes through the compressor 120 and flows toward the combustor 130 And the other end is provided so as to communicate with the flow path 161.

The heat insulating material 372 prevents the temperature rise of the compressed air moving along the first pipe 171. Since the first pipe 171 is adjacent to the combustor 130, the temperature of the first pipe 171 may be increased due to the influence of the combustor 130 when the first pipe 171 moves toward the flow path 161. However, in this embodiment, since the heat insulating material 372 is provided on the outer surface of the first pipe 171, the influence of the combustor 130 can be minimized and the temperature can be prevented from rising.

Hereinafter, the operation of the micro gas turbine including the bearing cooling unit according to the present invention will be described.

When the compressor (120) rotates by driving a motor (not shown), the external gas introduced into the compressor (120) is compressed to be a high pressure gas. At this time, the temperature of the gas compressed by the compressor 120 is about 200 ° C. The high-pressure gas is partially supplied to the flow passage 161 and the remainder is moved to the combustor 130 side to transfer energy to the turbine 140 as high-temperature and high-pressure air. The compressed air supplied to the oil passage 161 allows the bearing 150 to support the load applied to the shaft 110 by floating the shaft 110 between the shaft 110 and the bearing 150 rotating at a high speed .

A part of the air moving toward the combustor 130 flows into the first pipe 171 of the bearing cooling unit 170 and the remaining air is supplied to the combustor 130 to be a high temperature and high pressure gas.

The high pressure gas introduced into the first pipe 171 is cooled by mixing or exchanging heat with the external air supplied from the outside to the second pipes 172 and 272 or is supplied through the heat exchanger 372 ). The air supplied to the flow path 161 floats the shaft 110 to support the load. In addition, the compressed air is cooled, thereby preventing the bearing 150 from being overheated.

The bearing cooling unit 170 is installed at a midpoint of the shaft 110 and is supplied with a uniform amount to the compressor 120 and the turbine 140. The bearing cooling unit 170 adjusts thrust applied to the shaft 110, This is possible.

Therefore, according to the present invention, it is possible to drive an air bearing mounted on a shaft by using a high-pressure gas passed through a compressor, and prevent the temperature of the high-pressure gas from rising by mixing or exchanging heat between the outside air and the high- There is provided an ultra miniature gas turbine having a bearing cooling section capable of preventing damage.

The scope of the present invention is not limited to the above-described embodiments, but may be embodied in various forms of embodiments within the scope of the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

100: micro gas turbine with bearing cooling section
110: shaft 120: compressor
130: combustor 140: turbine
150: Bearing 160: Bearing housing
161: passage 170: bearing cooling section
171: first pipe 172,272: second pipe
372: Insulation

Claims (7)

A compressor mounted on the shaft and generating a high-pressure gas by receiving gas from the outside;
A combustor for receiving a high-pressure gas from the compressor to generate a high-temperature high-pressure gas;
A turbine mounted on the shaft and generating power by receiving energy from a high temperature and high pressure gas supplied from the combustor;
A bearing mounted on the shaft and supporting a load applied to the shaft using a high-pressure gas generated from the compressor;
A bearing housing enclosing the shaft and spaced apart from the shaft by a predetermined distance to form a flow path through which the high-pressure gas flows; And
And a bearing cooling unit for cooling a part of the high pressure gas generated from the compressor and moving toward the combustor,
The bearing cooling unit includes:
A first pipe through which the high-pressure gas flows and whose one end communicates with the flow path; And a second pipe arranged to surround the first pipe so that the high pressure gas and the outside air are mixed with each other and supplied to the flow path side and one area communicates with the first pipe And a bearing cooling section which is formed of a bearing. A compressor mounted on the shaft and generating a high-pressure gas by receiving gas from the outside;
A combustor for receiving a high-pressure gas from the compressor to generate a high-temperature high-pressure gas;
A turbine mounted on the shaft and generating power by receiving energy from a high temperature and high pressure gas supplied from the combustor;
A bearing mounted on the shaft and supporting a load applied to the shaft using a high-pressure gas generated from the compressor;
A bearing housing enclosing the shaft and spaced apart from the shaft by a predetermined distance to form a flow path through which the high-pressure gas flows; And
And a bearing cooling unit for cooling a part of the high pressure gas generated from the compressor and moving toward the combustor,
The bearing cooling unit includes:
A first pipe through which the high-pressure gas flows and whose one end communicates with the flow path; And a second pipe arranged to surround the first pipe and to receive external air to cool the high-pressure gas. ≪ Desc / Clms Page number 19 > 3. The method according to claim 1 or 2,
Wherein a part of the high-pressure gas generated from the compressor is supplied to the flow path and the remainder flows to the combustor side, and a part of the high-pressure gas moving to the combustor side is supplied to the bearing cooling section. Gas turbine. delete delete 3. The method according to claim 1 or 2,
Wherein the bearing cooling portion is installed at a half point in the longitudinal direction of the shaft. The method according to claim 6,
And the bearing cooling part is installed through the bearing housing.

Images