Turbo compressor having cooling-gas path tube members

Abstract

The present invention relates to a turbo compressor comprising: a motor having a rotary shaft at least one of the frond end and the rear end of which is coupled to an impeller so as to rotate same; a housing having a motor accommodation space for accommodating the motor; a cooling gas path, being a path in which the cooling gas flows, provided to allow cooling gas to pass through the motor accommodation space; cooling water paths formed to allow cooling liquid for cooling the housing to flow therein; and cooling-gas path tube members, being tube members in which the cooling gas flows, disposed in the respective cooling water paths to allow the cooling liquid to cool the outer surface thereof. According to the present invention, the cooling liquid flowing in the cooling water paths comes into direct contact with the outer surface of the cooling-gas path tube members so that the cooling gas flowing therein can be quickly cooled via "direct cooling," and thus a layout where the flow volume of the cooling gas can be relatively reduced is possible, enabling more effective compression across the entire compressor.

Description

Turbo compressor equipped with a tubular member for a cooling circuit

[0001] The present invention relates to a turbo compressor, and more particularly to a turbo compressor in which compressor efficiency is improved by rapidly cooling a cooling gas inside a tube member using a cooling liquid in a "direct cooling" manner.

[0002] A turbo compressor or turbo blower is a centrifugal pump that sucks in and compresses external air or gas by rotating an impeller at high speed and then blows it out. It is widely used for powder transfer and aeration in sewage treatment plants, and recently, it is also being used for industrial processes and for automotive applications.

[0003] Meanwhile, to produce high-pressure compressed gas, there is a single-stage compression method that uses a single impeller, and a multi-stage compression method that uses two or more impellers connected in series.

[0004] When using the above single-stage compression method, the maximum pressure of the compressed gas that can be produced is at the level of 3 to 4 bar, and the smaller the size, the lower the maximum pressure of the compressed gas becomes. Furthermore, due to the design factor called Specific Speed, the rotational speed must be very high, which causes the problem of having to increase the speed of the motor and inverter to rotate the impeller, and the problem of the overall energy efficiency inevitably decreases as losses due to windage loss on the bearing or rotor surface increase rapidly.

[0005] To compensate for these problems, a two-stage compression method is sometimes used, in which two impellers are directly connected to perform compression in two stages. In this case, although the maximum pressure of the compressed gas that can be produced increases, the efficiency of the second impeller decreases due to the temperature rise of the compressed gas resulting from "adiabatic compression." To solve this problem, a cooling device called an intercooler is installed between the first and second impellers to enable "isothermal compression." Using this multi-stage compression method has the advantage of solving various technical problems that occur in single-stage compression, as the rotational speed according to the specific velocity is reduced because the compression ratio shared by each impeller is low.

[0006] An example of a conventional two-stage turbo compressor is disclosed in Korean Patent Publication No. 10-2001-0010014, published on February 5, 2001. This turbo compressor includes an intercooler, which is a heat exchange device that cools high-temperature compressed air to within approximately 40°C.

[0007] However, conventional intercoolers are typically provided separately outside the housing surrounding the first impeller and the second impeller to increase cooling efficiency, as shown in Fig. 2 of the aforementioned Korean Patent Publication, and are usually manufactured as cooling devices of a considerably large volume to increase cooling efficiency.

[0008] To solve these problems, Korean Patent Publication (Registration No. 10-1845833, Registration Date 2018-03-30) disclosed a technology in which a cooling water channel for cooling a housing and an air cooling channel penetrating the housing are arranged in close proximity.

[0009] However, even in the technology disclosed in the above Korean Patent Publication (Registration No. 10-1845833), since the cooling water channel and the air cooling channel are separated from each other by a relatively thick metal housing wall of 4 mm or more, there is a limitation in that the cooling liquid flowing inside the cooling water channel can only cool the compressed gas flowing inside the air cooling channel by "indirect cooling" through heat conduction.

[0010] Therefore, conventional turbo compressors have a problem in that the cooling liquid flowing inside the cooling water channel does not cool the compressed gas flowing inside the air-cooling channel quickly enough to meet design requirements, and does not sufficiently cool the heat-generating components such as the stator, rotor, and bearings housed in the motor housing space, resulting in a decrease in overall compressor efficiency.

[0011] The present invention has been devised to solve the above problem, and its purpose is to provide a turbo compressor with an improved structure that allows a cooling liquid to rapidly cool a cooling gas inside a tube member in a "direct cooling" manner.

[0012] To achieve the above objective, the turbo compressor according to the present invention is a turbo compressor that compresses and supplies a gas, such as air, to the outside, and comprises: a compressed gas intake port into which the gas is sucked in; an impeller that compresses the gas introduced through the compressed gas intake port; a compressed gas outlet port into which the gas compressed by the impeller is discharged to the outside; a compression unit having a compressed gas flow path connected from the compressed gas intake port to the compressed gas outlet port; a motor having a rotation shaft extending along a first central axis, at least one of a front end or a rear end of which is coupled to the impeller to rotate the impeller; a housing having a motor receiving space for receiving the motor; a cooling path provided to pass through the motor receiving space as a path through which a cooling gas flows; a cooling water channel formed to allow a cooling liquid to flow to cool the housing; and a pipe member for the cooling path disposed inside the cooling water channel as a pipe member through which the cooling gas flows, so that the outer surface can be cooled by the cooling liquid.

[0013] Here, for the cooling device, it is preferable to use a portion of the compressed gas compressed by the impeller as the cooling gas.

[0014] Here, the tube member for the cooling path preferably comprises a metal tube having at least one spiral corrugation formed on its outer surface.

[0015] Here, it is preferable that the cooling gas starts from downstream of the impeller, passes through the interior of the cooling pipe member and the motor receiving space, and then joins downstream of the impeller.

[0016] Here, the compression unit comprises: a first impeller that primarily compresses the gas introduced through the compression gas intake port; a second impeller that secondarily compresses the gas compressed by the first impeller; and a compression gas outlet through which the gas compressed by the second impeller is discharged to the outside; wherein the rotating shaft has one end coupled to the first impeller and the other end coupled to the second impeller, and is provided in the compression gas flow path located between the first impeller and the second impeller, and includes an intercooler comprising an air cooling path through which the gas can pass, and the cooling path is preferably a path through which a portion of the compression gas compressed by the first impeller flows.

[0017] Here, it is preferable that the air cooling device be hidden inside the housing while penetrating the housing.

[0018] Here, the air cooling device is preferably formed as a spiral with the first central axis as the center of rotation.

[0019] Here, the housing comprises an inner housing having a motor receiving space; and an outer housing surrounding the inner housing; and the air cooling channel is preferably provided between the outer surface of the inner housing and the inner surface of the outer housing.

[0020]

[0021] Here, the cooling channel preferably includes a channel penetrating the housing to cool the housing.

[0022] Here, it is preferable that the cooling water channel be configured to exchange heat with the gas contained inside the air-cooling channel.

[0023] Here, it is preferable that the air cooling channel be positioned outside the cooling channel in the radial direction of the first central axis.

[0024] Here, it is preferable that cooling fins capable of increasing heat exchange efficiency are provided between the cooling water channel and the air cooling channel.

[0025] Here, the cooling channel is preferably formed in a zigzag shape by including: a plurality of unit channels extending along the first central axis and arranged spaced apart from each other along the circumferential direction of the first central axis; a plurality of rear channels connecting the rear ends of the unit channels to each other; and a plurality of front channels connecting the front ends of the unit channels to each other.

[0026] According to the present invention, the cooling channel is provided to pass through a motor receiving space as a channel through which a cooling gas flows; a cooling channel formed to allow a cooling liquid to flow to cool a housing; and a cooling channel pipe member disposed inside the cooling channel so that the outer surface can be cooled by the cooling liquid, as a pipe member through which the cooling gas flows in the internal hollow. Thus, the cooling liquid flowing inside the cooling channel comes into direct contact with the outer surface of the cooling channel pipe member, thereby rapidly cooling the cooling gas flowing inside by a "direct cooling" method. Accordingly, a design is possible that can relatively reduce the flow rate of the cooling gas, thereby increasing the compression efficiency of the entire compressor.

[0027] FIG. 1 is a cross-sectional view of a turbo compressor, which is an embodiment of the present invention.

[0028] Figure 2 is a right side view of the turbo compressor shown in Figure 1.

[0029] Figure 3 is a cross-sectional view along line III-III of the turbo compressor shown in Figure 1.

[0030] Figure 4 is a cross-sectional view along line IV-IV of the turbo compressor shown in Figure 1.

[0031] Figure 5 is a cross-sectional view of the VV line of the turbo compressor shown in Figure 1.

[0032] Figure 6 is a cross-sectional view along line VI-VI of the turbo compressor shown in Figure 1.

[0033] Figure 7 is a diagram illustrating the compressed gas flow (G) of the turbo compressor shown in Figure 1.

[0034] Figure 8 is a partial cross-sectional view of the turbo compressor shown in Figure 2.

[0035] Figure 9 is a diagram illustrating the cooling liquid flow (W) of the turbo compressor shown in Figure 1.

[0036] Figure 10 is a drawing for explaining the cooling path (C) of the turbo compressor shown in Figure 1.

[0037] FIG. 11 is a perspective view of a tube member for a cooling furnace shown in FIG. 1.

[0038] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0039] FIG. 1 is a cross-sectional view of a turbo compressor according to one embodiment of the present invention, FIG. 2 is a right side view of the turbo compressor shown in FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III of the turbo compressor shown in FIG. 1.

[0040] Referring to FIGS. 1 to 3, a turbo compressor (100) according to a preferred embodiment of the present invention is a centrifugal pump that sucks in and compresses external gas by rotating an impeller at high speed and then blows it out, and is also called a so-called turbo compressor or turbo blower. This turbo compressor (100) is configured to include a housing (10), a compression unit (20), a motor (30), an intercooler (40), a water cooling unit (50), a pipe member (61) for a cooling path, and a cooling gas path (C). In the following description, it is assumed that the gas to be compressed is air.

[0041]

[0042] The above housing (10) is a housing made of metal material and comprises an inner housing (11), an outer housing (12), a motor receiving space (13), and a rear housing (14).

[0043] The inner housing (11) is a cylindrical member having the motor receiving space (13) inside, has a cross-section with the first central axis (C1) as the center of the circle, and extends along the first central axis (C1).

[0044] The above motor receiving space (13) is a space having a shape corresponding to the motor (30) so as to be able to receive the motor (30) described later.

[0045] The inner housing (11) has an open left end (front end) and a right end (rear end) as shown in FIG. 1.

[0046] The outer housing (12) is a cylindrical member having a cross-section with the first central axis (C1) as the center of the circle, and is extended along the first central axis (C1).

[0047] The outer housing (12) has a shape corresponding to the inner housing (11) so as to be able to accommodate the inner housing (11) while surrounding it.

[0048] The inner surface of the outer housing (12) and the outer surface of the inner housing (11) face each other at a predetermined distance apart.

[0049] It is preferable to form the thickness of the portion of the side wall of the outer housing (12) facing the intercooler (40) as thin as possible.

[0050] The rear housing (14) is a metal housing that hermetically seals the rear end of the inner housing (11) and the outer housing (12).

[0051] The rear housing (14) may be manufactured in several separate parts for mounting the motor (30), and a detailed description thereof will be omitted.

[0052] The rear housing (14) includes a scroll (29) having a passage formed so that air passing through the second impeller (22) can flow spirally as shown in FIG. 2.

[0053] The scroll (29) connects the second impeller (22) and the compressed gas outlet (25) to each other.

[0054] The rear housing (14) is joined to the inner housing (11) and the outer housing (12) by means of bolts or screws.

[0055] In the front portion of the housing (10), as shown in FIG. 1 and FIG. 10, a cooling gas inlet (63) is formed so that a portion (C) of the compressed gas compressed by the first impeller (21) can enter the interior of the cooling pipe member (61).

[0056] That is, the cooling gas inlet (63) connects the downstream of the first impeller (21) and the inside of the cooling pipe member (61) to each other.

[0057] At the rear end of the housing (10), as shown in FIGS. 1 and FIGS. 10, a cooling gas outlet (64) is formed so that a portion of the compressed gas passing through the interior of the cooling pipe member (61) can advance into the motor receiving space (13).

[0058] That is, the above cooling gas outlet (64) connects the interior of the cooling pipe member (61) and the rear end of the motor receiving space (13) to each other.

[0059]

[0060] The above compression unit (20) is a device that sucks in and compresses external air, and is equipped with a first impeller (21), a second impeller (22), and a compressed gas flow path (23).

[0061] The first impeller (21) above is a wheel for sucking in and primarily compressing external air, and is equipped with a plurality of blades having curved surfaces and is mounted to enable high-speed rotation.

[0062] The first impeller (21) is positioned between the left end of the inner housing (11) and the left end of the outer housing (12).

[0063] In front of the first impeller (21), a compressed gas intake port (24) for sucking in external air is formed in the outer housing (12).

[0064] The second impeller (22) is a wheel for secondarily compressing the gas that has been first compressed by the first impeller (21), and is equipped with a plurality of blades having a curved surface like the first impeller (21) and is mounted to enable high-speed rotation.

[0065] The second impeller (22) is positioned between the right end of the inner housing (11) and the rear housing (14).

[0066] At the rear of the second impeller (22), a compressed gas intermediate intake port (26) into which the gas primarily compressed by the first impeller (21) is introduced is formed in the rear housing (14).

[0067] In the rear housing (14), as shown in FIG. 2, a compressed gas intermediate discharge port (27) is formed through which the gas primarily compressed by the first impeller (21) is discharged.

[0068] The air (G) discharged from the above-mentioned compressed gas intermediate discharge port (27) is introduced into the second impeller (22) through the above-mentioned compressed gas intermediate intake port (26) as shown in FIG. 8.

[0069] The above compressed gas path (23) is a path connected from the compressed gas intake port (24) to the compressed gas outlet (25).

[0070] The air sucked into the compressed gas intake port (24) is compressed as it travels along the compressed gas path (23) connected from the compressed gas intake port (24) to the compressed gas outlet (25).

[0071] As shown in FIG. 7, the above compressed gas flow path (23) is connected from the compressed gas intake port (24) to the first impeller (21), the intercooler (40), the compressed gas intermediate outlet (27), the compressed gas intermediate intake port (26), and the second impeller (22) in sequence, and then to the compressed gas outlet (25).

[0072] The above compressed gas path (23) includes a front path (23a), an intermediate path (23b), and a rear path (23c).

[0073] The above shear passage (23a) is a passage provided so that air can flow from the center of the housing (10) toward the outer edge of the shear portion of the housing (10).

[0074] The above shear path (23a) is a plurality of paths partitioned by a diffuser (28) and extends along the radial direction of the first central axis (C1).

[0075] The above intermediate path (23b) is a plurality of paths penetrating the housing (10) to cool the housing (10), and is extended around the first central axis (C1).

[0076] The above intermediate paths (23b) are arranged spaced apart from each other by a predetermined interval along the circumferential direction of the first central axis (C1), as shown in FIGS. 3 and 7.

[0077] The above-mentioned rear passage (23c) is a passage that connects air coming from the above-mentioned intermediate passage (23b) to the above-mentioned compressed gas intermediate intake port (26), and is formed at the rear end of the housing (10).

[0078] It is preferable that the above shear path (23a) and intermediate path (23b) be arranged in rotational symmetry or axial symmetry around the first central axis (C1).

[0079] The air sucked into the above-mentioned compressed gas intake port (24) can be compressed in two stages while moving along the compressed gas path (23) connected from the above-mentioned compressed gas intake port (24) to the above-mentioned compressed gas outlet (25).

[0080]

[0081] The motor (30) is an electric motor that generates rotational force and is a device for supplying high-speed rotational force to the impellers (21, 22). The motor (30) includes a rotating shaft (31), a stator (32), a rotor (33), and a bearing (34).

[0082] The above-mentioned rotational shaft (31) is a rod member extended along the first central axis (C1), with its front end connected to the first impeller (21) so as not to rotate relative to it, and its rear end connected to the second impeller (22) so as not to rotate relative to it.

[0083] The above stator (32) is a stator on which a field coil is wound, and is mounted in a fixed state in the motor receiving space (13).

[0084] The above rotor (33) is a rotor including a permanent magnet and is coupled to the middle part of the rotation shaft (31).

[0085] The above bearing (34) is an air bearing that rotatably supports the rotation shaft (31) in order to reduce the frictional force generated by high-speed rotation, and is provided at the front and rear ends of the rotation shaft (31), respectively.

[0086] There is a predetermined gap between the stator (32) and the rotor (33), between the rotation axis (31) and the stator (32), and between the rotation axis (31) and the bearing (34) in each case.

[0087] The above intercooler (40) is a device for cooling air heated by the first impeller (21) and includes an air cooling path (41) and a guide member (42).

[0088] The above air cooling path (41) is a path located between the first impeller (21) and the second impeller (22), and is a path through which air to be compressed flows. In this embodiment, at least a portion of the intermediate path (23b) functions as the air cooling path (41).

[0089] The above air cooling path (41) is hidden inside the housing (10) in a state where it penetrates the housing (10) in a hermetically sealed manner.

[0090] The above air cooling device (41) is formed in a coil or spiral shape with the first central axis (C1) as the center of rotation, as shown in FIG. 7.

[0091] The above air cooling path (41) is formed by the outer surface of the inner housing (11), the inner surface of the outer housing (12), and the surface of the cooling fin (52) to be described later, as shown in FIG. 3.

[0092] The above guide member (42) is a member for guiding the direction of the fluid flow of air compressed by the first impeller (21), and is provided in multiple numbers upstream of the air cooling path (41).

[0093] The guide member (42) is a member for guiding the air that has passed through the diffuser (28) to flow in a predetermined direction before entering the air cooling path (41).

[0094] The guide member (42) is provided to have a predetermined angle with respect to the first central axis (C1).

[0095]

[0096] The above water cooling unit (50) is a device for cooling the housing (10) using a cooling liquid, and is equipped with a cooling water channel (51), a cooling fin (52), a cooling liquid inlet (53), and a cooling liquid outlet (54). Here, water is used as the cooling liquid.

[0097] The above cooling channel (51) is a passage for receiving cooling liquid, and is formed to allow continuous flow of cooling liquid contained within.

[0098] The above cooling channel (51) is hidden inside the inner housing (11) while penetrating the inner housing (11) as shown in FIGS. 1 and 3, and includes a unit channel (51a), a rear channel (51b), and a front channel (51c).

[0099] The above unit channel (51a) is a channel with a circular cross-section hidden inside the inner housing (11) while penetrating the inner housing (11), and extends straight along the first central axis (C1).

[0100] As shown in FIG. 3, the above unit channels (51a) are arranged in a number of spaced-apart positions along the circumferential direction of the first central axis (C1).

[0101] Inside the above unit channel (51a), a pipe member (61) for the cooling channel is arranged as shown in FIGS. 1 and FIGS. 3.

[0102] The above-mentioned tube member (61) for cooling is a metal tube made of a thin metal plate with a thickness of less than or equal to a predetermined thickness. In this embodiment, the above-mentioned tube member (61) for cooling is made of a thin metal plate having a thickness of 1 mm or less and excellent thermal conductivity.

[0103] On the outer surface of the above-mentioned tube member (61) for cooling, at least one spiral corrugation is densely formed as shown in FIG. 11.

[0104] In this embodiment, since the tube member (61) for the cooling path is manufactured as a thin plate, the spiral corrugations are also formed on the inner surface of the tube member (61) for the cooling path.

[0105] In the hollow (62) of the above-mentioned pipe member (61) for cooling, a portion of the compressed gas (G) compressed by the first impeller (21) as shown in FIG. 10 flows as a cooling gas (C).

[0106] The above cooling pipe member (61) is positioned at a predetermined distance from the inner wall of the unit channel (51a) as shown in FIG. 3, so that the cooling liquid flowing inside the unit channel (51a) can be "directly cooled" by coming into contact with the outer surface of the cooling pipe member (61).

[0107] In this embodiment, the tube member (61) for the cooling channel is positioned in the center of the unit channel (51a) as shown in FIG. 3 and FIG. 10.

[0108] The above cooling pipe member (61) is provided to be airtight so that the cooling liquid of the above cooling water channel (51) cannot flow in.

[0109] In addition, the above cooling channel (51) is provided to be watertight so that the cooling liquid flowing inside it does not leak out to the outside.

[0110] The above-mentioned rear channel (51b) is a channel connecting the rear ends of the unit channels (51a) to each other, and is formed to be hidden inside the inner housing (11) while penetrating the rear end of the inner housing (11) as shown in FIG. 5.

[0111] The above-mentioned shear channel (51c) is a channel that connects the shear portions of the unit channel (51a) to each other, and is formed to be hidden inside the inner housing (11) while penetrating the shear portion of the inner housing (11) as shown in FIG. 4.

[0112] Accordingly, the cooling channel (51) is formed along the circumferential direction of the inner housing (11) in a zigzag shape as shown in FIG. 9, and is arranged to surround the entire side wall of the inner housing (11).

[0113] It is preferable that the above cooling water channels (51) be arranged in a rotationally symmetric or axially symmetric manner around the first central axis (C1).

[0114] It is preferable that the above cooling water channel (51) be positioned as close as possible to the above air cooling channel (41).

[0115] The above cooling channel (51) is positioned inside the air cooling channel (41) so as to be closer to the first central axis (C1).

[0116] The above cooling fin (52) is a cooling fin for increasing the heat exchange efficiency between the cooling liquid flowing along the cooling water channel (51) and the air flowing along the air cooling channel (41).

[0117] As shown in FIGS. 1 and 3, the cooling fin (52) protrudes radially from the outer surface of the inner housing (11) and extends along the first central axis (C1).

[0118] The above cooling fins (52) are arranged in a number along the circumferential direction of the inner housing (11) at spaced intervals from each other.

[0119] The end portion of the cooling fin (52) maintains contact with the inner surface of the outer housing (12).

[0120] The above cooling liquid inlet (53) is an inlet through which cooling liquid is introduced from the outside, is connected to one end of the cooling water channel (51), and is provided in the rear housing (14).

[0121] The above cooling liquid inlet (53) is connected to an externally provided pump (not shown), so water is supplied by the pump.

[0122] The above cooling liquid outlet (54) is an outlet through which the cooling liquid flows out to the outside, is connected to the other end of the cooling water channel (51), and is provided in the rear housing (14).

[0123] The cooling liquid discharged from the cooling liquid outlet (54) may be cooled externally and then flow back in through the cooling liquid inlet (53).

[0124]

[0125] The above cooling path (C) is a passage for cooling gas (C) to cool a heat-generating component housed in the motor housing space (13), and is configured so that a portion of the compressed gas compressed by the first impeller (21) can flow as cooling gas (C) after being branched.

[0126] In this embodiment, the cooling path (C) is configured such that, as shown in FIG. 10, the cooling gas (C) starts from downstream of the first impeller (21), passes through the cooling gas inlet (63) and enters the front end of the cooling path pipe member (61), then flows to the rear end of the cooling path pipe member (61), enters the motor receiving space (13) through the cooling gas outlet (64), and flows forward where the first impeller (21) is positioned, thereby cooling the heat-generating components such as the stator (32), rotor (33), and bearing (34) contained in the motor receiving space (13), and then joins downstream of the first impeller (21).

[0127]

[0128] Below, an example of how the turbo compressor (100) of the above-described configuration operates will be explained.

[0129] When the rotation shaft (31) of the motor (30) rotates, the first impeller (21) and the second impeller (22) rotate simultaneously, and the air (G) introduced through the compressed gas intake port (24) is compressed in two stages by passing through the first impeller (21), the intercooler (40), and the second impeller (22) in sequence, and is discharged to the outside through the compressed gas outlet (25).

[0130] The air passing through the first impeller (21) has its speed reduced and its pressure increased as it passes through the diffuser (28), and as it passes through the guide member (42), the direction of the flow is changed at an angle suitable for entering the air cooling path (41).

[0131] The air passing through the guide member (42) is rapidly cooled as it passes through the air cooling path (41). At this time, since the air cooling path (41) is close to the cooling water path (51) and the outer housing (12), the air flowing through the air cooling path (41) is cooled by the cooling liquid inside the cooling water path (51) and at the same time is cooled by the atmosphere outside the outer housing (12).

[0132] Meanwhile, the cooling liquid contained inside the cooling water channel (51) is introduced from the cooling liquid inlet (53) and forms a cooling liquid flow (W) that flows along the circumferential direction of the inner housing (11) in a zigzag shape as shown in FIG. 9, and after cooling the inner housing (11) and the outer housing (12) as a whole, is discharged through the cooling liquid outlet (54).

[0133] At this time, the air flowing through the air cooling channel (41) is rapidly cooled by the cooling liquid flowing through the unit channel (51a) adjacent to the air cooling channel (41). In particular, the heat exchange efficiency between the cooling liquid flowing through the unit channel (51a) and the air flowing through the air cooling channel (41) is greatly increased by the cooling fins (52).

[0134] And, some of the air (C) that has passed through the first impeller (21) enters the front end of the cooling pipe member (61) through the cooling gas inlet (63) as shown in FIG. 10, and then flows to the rear end of the cooling pipe member (61). At this time, the air inside the cooling pipe member (61) is rapidly cooled by the cooling liquid flowing inside the unit channel (51a).

[0135] The cooling gas (C) cooled in this way enters the motor receiving space (13) through the cooling gas outlet (64) and flows forward where the first impeller (21) is positioned, rapidly cooling the heat-generating components such as the stator (32), rotor (33), and bearing (34) contained in the motor receiving space (13), and then joins downstream of the first impeller (21) through a gap formed near the end of the first impeller (21), thereby flowing into the front path (23a) of the compressed gas path (23).

[0136]

[0137] The turbo compressor (100) of the above configuration is a turbo compressor that compresses a gas, such as air, and supplies it to the outside, comprising: a compressed gas intake port (24) into which the gas is sucked in; a first impeller (21) that compresses the gas introduced through the compressed gas intake port (24); a compressed gas outlet (25) into which the gas compressed by the first impeller (21) is discharged to the outside; a compression unit (20) having a compressed gas flow path (23) connected from the compressed gas intake port (24) to the compressed gas outlet (25); a motor (30) having a rotating shaft (31) in which the front end is coupled to the impeller (21) to rotate the first impeller (21); a housing (10) having a motor receiving space (13) that accommodates the motor (30); and a cooling path (C) provided to pass through the motor receiving space (13) as a path through which a cooling gas (C) flows. The device includes a cooling channel (51) formed to allow a cooling liquid (W) to flow to cool the housing (10); and a cooling pipe member (61) disposed inside the cooling channel (51a) so that the outer surface can be cooled by the cooling liquid, wherein the cooling liquid flowing inside the unit channel (51a) comes into direct contact with the outer surface of the cooling pipe member (61) to rapidly cool the cooling gas (C) flowing inside it in a "direct cooling" manner. Accordingly, the device has the advantage of being able to design the device so that the flow rate of the cooling gas (C) flowing inside the cooling pipe member (61) can be relatively reduced, thereby increasing the compression efficiency of the entire compressor.

[0138] In fact, according to the present invention, the efficiency of the turbo compressor can be increased by 2 to 3% or more compared to the conventional one, and this figure of performance improvement corresponds to a very large value considering that it is very difficult to improve the performance of the turbo compressor.

[0139] In addition, the turbo compressor (100) has the advantage that, since the cooling path (C) uses a portion (C) of the compressed gas (G) compressed by the impeller (21) as the cooling gas (C), there is no need to provide a separate cooling fan to circulate the cooling gas (C).

[0140] And the above turbo compressor (100) has the advantage of being able to sufficiently increase the thermal conductivity between the cooling gas (C) flowing inside the cooling pipe member (61) and the cooling liquid flowing inside the unit channel (51a), unlike a metal tube with a smooth surface, because the cooling pipe member (61) includes a metal tube having at least one spiral corrugation formed on its outer surface. This is because the surface area of ​​the inside and outside of the cooling pipe member (61) is relatively increased, and the fluid (C, F) flowing along the inner or outer surface of the cooling pipe member (61) swirls, thereby enabling the generation of turbulence flow.

[0141] In addition, the turbo compressor (100) has the advantage of easily forming a circulation flow of the cooling path (C) as shown in FIG. 10, because the cooling gas (C) starts from downstream of the impeller (21), passes through the internal hollow (62) of the cooling path pipe member (61) and the motor receiving space (13), and then joins downstream of the impeller (21).

[0142] And the turbo compressor (100) comprises: a first impeller (21) that primarily compresses the gas introduced through the compressed gas intake port (24) of the compression unit (20); and a second impeller (22) that secondarily compresses the gas compressed by the first impeller (21); The device is equipped with a compressed gas outlet (25) through which the gas compressed by the second impeller (22) is discharged to the outside; and the rotating shaft (31) is provided with one end connected to the first impeller (21) and the other end connected to the second impeller (22), and is provided in the compressed gas flow path (23) located between the first impeller (21) and the second impeller (22), and is equipped with an intercooler (40) including an air cooling path (41) through which the gas can pass, and since the cooling path (C) is a path through which a portion of the compressed gas (G) compressed by the first impeller (21) flows, there is an advantage in being able to manufacture a high-efficiency turbo compressor that simultaneously has the intercooler (40) and the cooling path (C).

[0143] In addition, the turbo compressor (100) has the advantage that the overall product size can be reduced through the integration of the intercooler (40) and the housing (10) because the air cooling path (41) is hidden inside the housing (10) in a hermetically sealed manner, and the intercooler (40) can be used for various purposes and there is no possibility of damage to the intercooler (40) due to external impact.

[0144] And the turbo compressor (100) has the advantage that the air cooling path (41) is formed in a spiral shape with the first central axis (C1) as the center of rotation, so the contact area between the air inside the air cooling path (41) and the housing (10) is increased, and the air inside the air cooling path (41) can be cooled quickly.

[0145] In addition, the turbo compressor (100) has the advantage that the housing (10) has an inner housing (11) having a motor receiving space (13); and an outer housing (12) surrounding the inner housing (11), and the air cooling path (41) is provided between the outer surface of the inner housing (11) and the inner surface of the outer housing (12), so that it is easy to form the cooling fins (52) and the air cooling path (41).

[0146] And since the above cooling water channel (51) includes water channels (51a, 51b, 51c) that penetrate the housing (10) so as to cool the housing (10), compared to the case where a separate cooling pipe is used, there is an advantage of excellent cooling efficiency and almost no possibility of leakage.

[0147] In addition, the turbo compressor (100) has the advantage that the cooling water channel (51) is configured to exchange heat with the air contained inside the air cooling channel (41), thereby cooling the housing (10) heated by heat generated from the motor (30) and bearing (34), and at the same time cooling the air flowing inside the air cooling channel (41).

[0148] And the turbo compressor (100) has the advantage that, since the air cooling channel (41) is positioned outside the cooling channel (51) in the radial direction of the first central axis (C1), the air flowing inside the air cooling channel (41) is cooled by the cooling liquid inside the cooling channel (51) in a water-cooling manner, and at the same time, can be cooled by the atmosphere outside the outer housing (12) in an air-cooling manner.

[0149] In addition, the turbo compressor (100) has the advantage of increasing the heat exchange efficiency between the air flowing inside the air cooling channel (41) and the cooling liquid flowing inside the cooling channel (51) because a cooling fin (52) capable of increasing the heat exchange efficiency is provided between the cooling channel (51) and the cooling liquid flowing inside the cooling channel (51).

[0150] And the turbo compressor (100) has the advantage of being formed in a zigzag shape by including: a plurality of unit channels (51a) that are spaced apart from each other along the circumferential direction of the first central axis (C1) and the cooling channel (51) extends along the first central axis (C1); a plurality of rear channels (51b) that connect the rear ends of the unit channels (51a); and a plurality of front channels (51c) that connect the front ends of the unit channels (51a). This allows the cooling liquid inside the cooling channel (51) to be in contact with the inner housing (11) to be maximized, and the cooling liquid can flow evenly over the entire inner housing (11).

[0151]

[0152] In this embodiment, the cooling path (C) has an "open structure" in which a portion of the compressed gas compressed by the first impeller (21) is used as a cooling gas, but it is obvious that, as in the Korean registered patent (Registration No. 10-1888156, Registration Date 2018-08-07), the cooling path (C) can be formed as a "closed structure" in which the cooling path (C) is continuously circulated while being spatially separated from the compressed gas path (23). In this case, a cooling fan may be additionally required to forcibly circulate the cooling gas contained inside the cooling path (C).

[0153] In this embodiment, the turbo compressor (100) is equipped with the first impeller (21) and the second impeller (22), but it is also possible to have a configuration that does not include the second impeller (22) and only includes the first impeller (21), as in the Korean registered patent (Registration No. 10-1888156, Registration Date 2018-08-07).

[0154] In this embodiment, the cooling gas (C) is configured to start from downstream of the first impeller (21), cool the heat-generating component housed in the motor housing space (13), and then join downstream of the first impeller (21); however, it is also possible to configure it to join upstream of the first impeller (21).

[0155] In this embodiment, the cooling fin (52) is integrally formed on the outer surface of the inner housing (11), but it is obvious that the cooling fin (52) can be processed into a separate member and then joined by a method such as press-fitting.

[0156] In this embodiment, the air cooling device (41) is formed in a coil or spiral shape with the first central axis (C1) as the center of rotation as shown in FIG. 7, but it is also possible to form it in a straight line along the first central axis (C1).

[0157] In this embodiment, the bearing (34) is provided as an air bearing, but of course, other types of bearings may also be used.

[0158] In this embodiment, a separate sealing means for airtightness is not described, but it is obvious that various types of sealing means may be used.

[0159] The present invention has been described above. However, the technical scope of the present invention is not limited to the contents described in the embodiments above, and it is evident that equivalent configurations modified or changed by those skilled in the art do not deviate from the scope of the technical concept of the present invention.

Claims

1. A turbo compressor that compresses gases such as air and supplies them externally, A compression unit comprising: a compression gas intake port into which the above gas is sucked in; an impeller that compresses the gas introduced through the compression gas intake port; a compression gas outlet into which the gas compressed by the impeller is discharged to the outside; and a compression gas flow path connected from the compression gas intake port to the compression gas outlet. A motor having a rotation axis extending along a first central axis, wherein at least one of a front end or a rear end is coupled to the impeller to rotate the impeller; A housing having a motor receiving space for accommodating the above motor; A cooling path provided to pass through the motor receiving space, as a path through which cooling gas flows; A cooling channel formed to allow a cooling liquid to flow for cooling the above housing; A turbo compressor characterized by including: a pipe member for a cooling channel disposed inside the cooling channel so that the outer surface can be cooled by the cooling liquid, wherein the pipe member through which the cooling gas flows is a pipe member within.

2. In Paragraph 1, The above cooling path is a turbo compressor characterized by using a portion of the compressed gas compressed by the impeller as a cooling gas.

3. In Paragraph 1, The above-mentioned tube member for the cooling path is characterized by comprising a metal tube having at least one spiral corrugation formed on its outer surface, in a turbo compressor 4. In Paragraph 2, A turbo compressor characterized in that the cooling gas starts from downstream of the impeller, passes through the interior of the cooling pipe member and the motor receiving space, and then joins downstream of the impeller.

5. In Paragraph 1, The above compression unit comprises: a first impeller that primarily compresses gas introduced through the compressed gas intake port; a second impeller that secondarily compresses the gas compressed by the first impeller; and a compressed gas outlet through which the gas compressed by the second impeller is discharged to the outside. The above-mentioned rotating shaft has one end connected to the first impeller and the other end connected to the second impeller, and The device comprises an intercooler provided in the compressed gas path located between the first impeller and the second impeller, and including an air-cooling path through which the gas can pass. A turbo compressor characterized in that the above cooling path is a path through which a portion of the compressed gas compressed by the first impeller flows.

6. In Paragraph 5, The above air-cooling path is characterized by being hidden inside the housing while penetrating the housing, in a turbo compressor 7. In Paragraph 5, The above air-cooling path is characterized by being formed as a spiral with the first central axis as the center of rotation, in a turbo compressor 8. In Paragraph 5, The above housing comprises an inner housing having a motor receiving space; and an outer housing surrounding the inner housing. The above air cooling path is characterized by being provided between the outer surface of the inner housing and the inner surface of the outer housing.

9. In Paragraph 1, The above cooling channel is characterized by including a channel penetrating the housing to cool the housing, in a turbo compressor 10. In Paragraph 5, A turbo compressor characterized in that the above cooling water channel is provided to exchange heat with the gas contained inside the air-cooling channel.

11. In Paragraph 5, The above air-cooling path is characterized by being disposed outside the cooling water path in the radial direction of the first central axis, in a turbo compressor 12. In Paragraph 5, A turbo compressor characterized by having cooling fins provided between the cooling water channel and the air cooling channel to increase heat exchange efficiency.

13. In Paragraph 1, The above cooling waterway is, A turbo compressor characterized by being formed in a zigzag shape by including: a plurality of unit channels extending along the first central axis and arranged spaced apart from each other along the circumferential direction of the first central axis; a plurality of rear channels connecting the rear ends of the unit channels to each other; and a plurality of front channels connecting the front ends of the unit channels to each other.

Images