Compressor system

Abstract

A compressor system includes a compressor housing, a shaft rotatably supported within the compressor housing, a first impeller operably connected to the shaft at a first end, a second impeller operably connected to the shaft at a second end, a motor operably connected to the shaft, and a cooling circuit. The cooling circuit includes a coolant inlet passage for introducing an inlet coolant flow into the cooling circuit, and a cooling channel fluidly connected with the coolant inlet passage. The cooling channel extends helically around the motor and includes a first portion and a second portion. Each of the first and second portions extends from the coolant inlet passage to a respective first and second outlet, such that the inlet coolant flow is split into a first coolant flow along the first portion and a second coolant flow along the second portion.

Description

Technical Field

[0001] The field of this disclosure generally relates to cooling systems for compressors, and more specifically to cooling systems for use with centrifugal compressors and refrigeration systems including cooling systems. Background Technology

[0002] Centrifugal compressors offer certain advantages over positive displacement compressor designs, such as reciprocating, rotary, and screw compressors. However, the integration of centrifugal compressors into low-capacity cooling systems can be limited due to the high impeller speeds and the associated challenges of providing a suitable operating environment for the impeller and associated motor. A particular challenge lies in providing adequate cooling to the motor and bearings associated with the compressor shaft to maintain them within suitable operating temperature ranges.

[0003] Conventionally, two-stage compressors have multiple inlets for introducing coolant into separate cooling paths. For example, some two-stage compressors may include a first coolant inlet and a first coolant path for supplying coolant to one or more bearings in the first compression stage, a second coolant inlet and a second coolant path for supplying coolant to one or more bearings in the second compression stage, and a third coolant inlet and a third coolant flow path for supplying coolant to the motor. Multiple coolant paths and / or inlets located at different locations or on different sides of the compressor can increase cost and complexity.

[0004] This background section is intended to introduce the reader to various aspects of the prior art that may be related to the various aspects of this disclosure described below and / or claimed. This discussion is intended to help provide the reader with background information to facilitate a better understanding of the various aspects of this disclosure. Therefore, it should be understood that these statements should be read in this light, rather than as an admission of prior art. Summary of the Invention

[0005] In one aspect, the compressor system includes a compressor housing, a shaft rotatably supported within the compressor housing by a first bearing and a second bearing, a first impeller operably connected to the shaft at a first end, and a second impeller operably connected to the shaft at a second end. The compressor system also includes a motor operably connected to the shaft between the first and second bearings, and a cooling circuit. The cooling circuit includes a coolant inlet passage defined by the compressor housing for introducing an inlet coolant flow into the cooling circuit, and a cooling passage defined by the compressor housing and fluidly connected to the coolant inlet passage. The cooling passage extends helically around the motor and includes a first portion and a second portion. Each of the first and second portions extends from the coolant inlet passage to a corresponding first outlet and second outlet, such that the inlet coolant flow is divided into a first coolant flow along the first portion and a second coolant flow along the second portion.

[0006] On the other hand, the compressor system includes a compressor housing, a shaft rotatably supported within the compressor housing by a first bearing and a second bearing, a first impeller operably connected to the shaft at a first end, and a second impeller operably connected to the shaft at a second end. The compressor system also includes a motor operably connected to the shaft between the first and second bearings, and a cooling circuit. The cooling circuit includes a coolant inlet passage defined by the compressor housing for introducing an inlet coolant flow into the cooling circuit, and a cooling passage defined by the compressor housing and fluidly connected to the coolant inlet passage. The cooling passage extends helically around the motor. The cooling passage includes a first portion and a second portion. Each of the first and second portions extends from the coolant inlet passage to a corresponding first outlet and second outlet, such that the inlet coolant flow is divided into a first coolant flow along the first portion and a second coolant flow along the second portion. Each of the first and second portions has a corresponding flow resistance coefficient, and the flow resistance coefficient of the first portion is greater than that of the second portion.

[0007] In another aspect, the compressor system includes a compressor housing, a shaft rotatably supported within the compressor housing by a first bearing and a second bearing, a first impeller operably connected to the shaft at a first end, and a second impeller operably connected to the shaft at a second end. The compressor system includes a motor operably connected to the shaft between the first and second bearings, and a cooling circuit. The cooling circuit includes a coolant inlet passage defined by the compressor housing for introducing an inlet coolant flow into the cooling circuit, and a channel fluidly connected to the coolant inlet passage. The channel is at least partially wound around the motor. The channel includes a first portion and a second portion, each of which extends from the coolant inlet passage to a corresponding first outlet and second outlet, such that the inlet coolant flow is divided into a first coolant flow along the first portion and a second coolant flow along the second portion. The cross-sectional area of ​​the first portion is substantially the same as that of the second portion, and wherein the first portion has a first length longer than a second length of the second portion.

[0008] In one aspect, a compressor system includes a compressor housing, a shaft rotatably supported within the compressor housing by a first bearing and a second bearing, a first impeller operably connected to the shaft at a first end, a second impeller operably connected to the shaft at a second end, and a motor operably connected to the shaft between the first and second bearings. The compressor system includes a cooling circuit including a first coolant inlet passage defined by the compressor housing for introducing a first coolant flow into the cooling circuit, and a second coolant inlet passage defined by the compressor housing for introducing a second coolant flow into the cooling circuit. The cooling circuit includes a cooling passage defined by the compressor housing and fluidly connected to the first and second coolant inlet passages. The cooling passage extends helically around the motor and includes a first portion and a second portion. The first portion extends from the first coolant inlet passage to a first outlet, and the second portion extends from the second coolant inlet passage to a second outlet, such that the first coolant flow travels along the first portion, and the second coolant flow travels along the second portion.

[0009] On the other hand, the compressor system includes a compressor housing, a shaft rotatably supported within the compressor housing by a first bearing and a second bearing, a first impeller operably connected to the shaft at a first end, and a second impeller operably connected to the shaft at a second end. The compressor system includes a motor operably connected to the shaft between the first and second bearings, and a cooling circuit. The cooling circuit includes a first coolant inlet passage defined by the compressor housing for introducing a first coolant flow into the cooling circuit, a second coolant inlet passage defined by the compressor housing for introducing a second coolant flow into the cooling circuit, and a cooling passage defined by the compressor housing and fluidly connected to the first and second coolant inlet passages. The cooling passage extends helically around the motor and includes a first portion and a second portion. The first portion extends from the first coolant inlet passage to a first outlet, and the second portion extends from the second coolant inlet passage to a second outlet, such that the first coolant flow travels along the first portion, and the second coolant flow travels along the second portion. Each of the first and second portions has a corresponding flow resistance coefficient. The flow resistance coefficient of the first portion is different from that of the second portion.

[0010] In another aspect, the compressor system includes a compressor housing, a shaft rotatably supported within the compressor housing by a first bearing and a second bearing, a first impeller operably connected to the shaft at a first end, and a second impeller operably connected to the shaft at a second end. The compressor system includes a motor operably connected to the shaft between the first and second bearings, and a cooling circuit. The cooling circuit includes a first coolant inlet passage defined by the compressor housing for introducing a first coolant flow into the cooling circuit, a second coolant inlet passage defined by the compressor housing for introducing a second coolant flow into the cooling circuit, and a cooling passage defined by the compressor housing and fluidly connected to the first and second coolant inlet passages, wherein the cooling passage extends helically around the motor and includes a first portion and a second portion. The first portion extends from the first coolant inlet passage to a first outlet, and the second portion extends from the second coolant inlet passage to a second outlet, such that the first coolant flow travels along the first portion, and the second coolant flow travels along the second portion. The cross-sectional area of ​​the first portion is substantially the same as the cross-sectional area of ​​the second portion. The second outlet area is larger than the first outlet area.

[0011] Various modifications exist to the features indicated in relation to the aspects mentioned above in this disclosure. Other features may also be included in the aspects mentioned above in this disclosure. These modifications and additional features may exist individually or in any combination. For example, various features discussed below with respect to any embodiment of the illustrated embodiments of this disclosure may be incorporated individually or in any combination into any of the foregoing aspects of this disclosure. Attached Figure Description

[0012] Figure 1 This is a 3D view of an example compressor.

[0013] Figure 2 yes Figure 1 The compressor shown is a side view.

[0014] Figure 3 It is suitable for and Figure 1 A schematic diagram of an example refrigeration system using the compressor shown.

[0015] Figure 4 It is along Figure 1 The compressor is shown in a cross-sectional view taken by line 4-4.

[0016] Figure 5 It is along Figure 1 The figure shown is a cross-sectional view of the compressor housing taken by line 5-5.

[0017] Figure 6 yes Figure 5 The three-dimensional sectional view of the shell shown.

[0018] Figure 7 yes Figure 6 The middle of " Figure 7 "A magnified view of a portion of the indicated housing."

[0019] Figure 8 yes Figure 6 The middle of " Figure 8 "A magnified view of a portion of the indicated housing."

[0020] Figure 9 It is along Figure 1 The diagram shows a cross-sectional view of the casing of another compressor, taken by line 5-5.

[0021] In all the accompanying drawings, the corresponding reference numerals indicate the corresponding parts. Detailed Implementation

[0022] In some embodiments of the compressor housing and coolant flow path described herein, coolant fluid can be delivered to multiple components of the compressor by means of a single inlet line supplying coolant flow to a single inlet port. This reduces or eliminates the need for multiple separate coolant delivery lines and inlet ports, and improves ease of use and / or reduces installation time and associated costs. For example, a technician will only need to install a single coolant line and / or connect a single flow control device, such as a solenoid valve, to a single inlet.

[0023] Implementations of the coolant flow path described herein enable the selective distribution of inlet coolant flow to components of the compressor. For example, the coolant flow path includes one or more features that divert a majority of the inlet coolant flow to a compression stage (e.g., a first or second compression stage) – compared to the amount of inlet coolant flow delivered to another compression stage. In some implementations, for example, one compression stage (e.g., a second compression stage) has a higher operating temperature compared to another compression stage (e.g., a first compression stage). The higher operating temperature of one compression stage may be at least partly caused by a larger load on that compression stage compared to the other. The increased pressure of the working fluid received by the compression stage increases the load on that compression stage and also increases its operating temperature. For example, a first compression stage compresses the working fluid from a first pressure to a second pressure greater than the first pressure. A second compression stage, located downstream of the first compression stage, receives the compressed working fluid at the second pressure, and therefore has a larger load and also a higher operating temperature compared to the first compression stage. Therefore, a larger volume of coolant can be delivered to the compression stage, which has a higher operating temperature, to help cool the compressor more evenly.

[0024] Implementations of the coolant flow path include a cooling channel comprising a first section for conveying coolant flow to a first compression stage and a second section for conveying coolant flow to a second compression stage. Each of the first and second sections can be characterized by a flow resistance parameter influenced by one or more characteristics of the channel. One or more characteristics of the coolant flow path that divert inlet coolant flow to different components of the compressor can be passive features that eliminate the need for additional flow control devices and / or complex control systems. For example, the coolant flow path may include a first flow path directed toward a first bearing and a second flow path directed toward a second bearing, wherein the first flow path is longer than the second flow path. Additionally or alternatively, the first flow path may include an outlet having a cross-sectional area larger than that of the outlet of the second flow path.

[0025] In another embodiment described herein, coolant flow is supplied to two inlet ports arranged adjacent to each other, such that the cooling passage includes a first section for conveying coolant flow to a first compression stage, a second section for conveying coolant flow to a second compression stage, and a third section disposed between the first and second sections for conveying coolant flow to a motor. The first and second sections have shortened distances from the outlets of the first and second compression stages, thereby enabling coolant flow to be supplied to the first and second compression stages without delay. Furthermore, a majority of the total inlet coolant flow is conveyed to the first and second compression stages, and a small portion of the total inlet coolant flow is conveyed to the motor, thereby improving the distribution of coolant flow. The embodiments described herein enable the delivery of a relative amount of coolant flow to each component based on the relative operating temperature of the compressor components.

[0026] This document describes in detail exemplary embodiments of a coolant flow system. Aspects of the coolant flow system are not limited to the specific embodiments described herein, but rather, components of the coolant flow system can be used independently and separately from other components described herein. For example, in some embodiments, the coolant flow system includes an inlet coolant flow path divided into a first flow path and a second flow path. The first flow path may be longer than the second flow path, or additionally and / or alternatively, the first flow path may have an outlet smaller than the outlet of the second flow path.

[0027] As used herein, the terms “about,” “approximately,” “basically,” and “about” when used in conjunction with a range of size, concentration, temperature, or other physical or chemical properties or characteristics mean to cover variations that may exist within the upper and / or lower limits of the range of the property or characteristic, including variations caused, for example, by rounding, measurement methods, or other statistical variations.

[0028] For the sake of brevity, an example of a two-stage centrifugal compressor will be described. However, the methods and systems described herein can be applied to other suitable compressors. The compressor's bearings, motor, and other drive components can be cooled using steam injected into the coolant path inlet by transferring the various parts of the main stream to the coolant circuit connected to a heat exchanger or flash tank.

[0029] Figure 1This is a perspective view of an example two-stage refrigeration compressor 100. The compressor 100 is operable to compress a working fluid (e.g., refrigerant), and includes a compressor housing 102 forming at least one sealed cavity within which each stage of refrigerant compression is performed. The compressor 100 includes: a first refrigerant inlet 110 that introduces refrigerant vapor into a first compression stage 124; a first refrigerant outlet 114; a refrigerant transfer conduit 112 that transfers compressed refrigerant from the first compression stage 124 to a second compression stage 126; a second refrigerant inlet 118 that introduces refrigerant vapor into the second compression stage 126; and a second refrigerant outlet 120. The refrigerant transfer conduit 112 is operatively connected at opposite ends to the first refrigerant outlet 114 and the second refrigerant inlet 118. The refrigerant transfer conduit 112 also includes a port 122 for adding flow between the first compression stage 124 and the second compression stage 126. The second refrigerant outlet 120 delivers compressed refrigerant from the second compression stage 126 to... Figure 3 The cooling system 200 shown incorporates a compressor 100.

[0030] Reference Figure 4 The compressor housing 102 encloses a first compression stage 124 and a second compression stage 126 located at opposite ends of the compressor 100. The first compression stage 124 includes a first impeller 106 configured to increase kinetic energy into the refrigerant entering via the first refrigerant inlet 110. The kinetic energy imparted to the refrigerant by the first impeller 106 is converted into increased refrigerant pressure as the refrigerant velocity decreases during its transfer to a sealed cavity (e.g., a diffuser) formed within the volute 132. The first compression stage 124 also includes a first variable inlet guide vane (VIGV) 134 disposed upstream of the first impeller 106 in the first refrigerant inlet 110. The first variable inlet guide vane 134 includes a plurality of blades whose positions can be controlled to introduce a pre-vortex into the gaseous refrigerant entering the first refrigerant inlet 110.

[0031] Similarly, the second compression stage 126 includes a second impeller 116 configured to increase the kinetic energy of the refrigerant entering from the first compression stage 124 via the second refrigerant inlet 118. The kinetic energy imparted to the refrigerant by the second impeller 116 is converted into increased refrigerant pressure as the refrigerant velocity decreases during its transfer to a sealed cavity (e.g., a diffuser) formed within the volute 138. The compressed refrigerant exits the second compression stage 126 via the second refrigerant outlet 120.

[0032] The second compression stage 126 also includes a second variable inlet guide vane (VIGV) 136 disposed upstream of the second impeller 116 in the second refrigerant inlet 118. The second variable inlet guide vane 136 includes a plurality of blades whose positions can be controlled to introduce a pre-vortex into the gaseous refrigerant entering the second refrigerant inlet 118.

[0033] The first impeller 106 and the second impeller 116 are connected at opposite ends of the shaft 104, which includes a longitudinal axis A extending between the first shaft end 140 and the second shaft end 142. 104 Shaft 104 is operably connected to motor 108 (e.g., operably connected to motor 108 via magnetic interaction between rotor and stator 394). Motor 108 is positioned between first impeller 106 and second impeller 116, for example, approximately midway between the first impeller 106 and second impeller 116, such that the first impeller 106 and second impeller 116 rotate at a selected rotational speed to compress the refrigerant to a pre-selected pressure exiting second refrigerant outlet 120. Any suitable motor, including but not limited to an electric motor, can be incorporated into compressor 100. Motor 108 may include a motor temperature sensor (not shown) operable to determine the temperature of motor 108. The motor temperature sensor may be a thermocouple, thermistor, resistance temperature detector (RTD), or any other suitable sensor.

[0034] Shaft 104 is rotatably supported by a first bearing assembly 160 associated with and positioned within a first bearing housing 162, and a second bearing assembly 164 associated with and positioned within a second bearing housing 166, and a second bearing housing 164 associated with and positioned within a second bearing housing 166. Each of the first bearing housing 162 and the second bearing housing 166 includes a mounting structure for connecting the respective bearing housing to the compressor housing 102. The first bearing assembly 160 and the second bearing assembly 164 rotatably support shaft 104 at opposite ends, wherein a motor 108 is disposed between the first bearing assembly 160 and the second bearing assembly 164. In some embodiments, the first bearing housing 162 and the second bearing housing 166 may each include a radial bearing and / or a thrust bearing. In some embodiments, the first bearing assembly 160 and the second bearing assembly 164 may include a gas foil bearing.

[0035] Figure 3 It can be implemented within it. Figure 1 A schematic diagram of an example refrigeration system 200 using a compressor. The refrigeration system 200 includes a compressor 202 (e.g., compressor 100), a condenser 204, an expansion device 206 (e.g., expansion valve, orifice, capillary tube), and an evaporator 208. Without departing from the scope of this disclosure, the refrigeration system 200 may include, in addition to those shown in the reference diagram, other components. Figure 3 Additional or other components besides those shown and described.

[0036] In operation, compressor 202 receives a working fluid, such as refrigerant, as a low-pressure gas through suction line 210. Compressor 202 compresses the low-pressure refrigerant gas, thereby increasing the temperature and pressure of the refrigerant. The compressed, high-temperature refrigerant leaving compressor 202 is directed toward and through condenser 204, where it is condensed into a high-pressure liquid or a high-pressure liquid-gas mixture. The compressed, condensed refrigerant leaving condenser 204 is directed toward and through expansion device 206, which expands the refrigerant, thereby reducing its pressure. The expanded (or "uncompressed") refrigerant leaving expansion device 206 can be a gas or a mixture of gas and liquid after passing through expansion device 206. The uncompressed refrigerant leaving expansion device 206 is directed toward and through evaporator 208. The uncompressed refrigerant fluid evaporates into a gas in evaporator 208. Uncompressed refrigerant gas leaving evaporator 208 is guided back to compressor 202 via suction line 210, where the working fluid is compressed again and the process is repeated.

[0037] Example refrigeration system 200 includes a compressor cooling system 212 that draws working fluid (e.g., refrigerant) from a portion of the main refrigeration loop (i.e., a refrigeration loop in which the working fluid is compressed using compressor 202, condensed using condenser 204, expanded using expansion device 206, and evaporated using evaporator 208). The working fluid used in cooling system 212 is transferred from the main refrigeration loop and directed toward compressor 202 via coolant supply line 220 to cool components of compressor 202, such as the motor and bearings of compressor 202. The working fluid used in compressor cooling system 212 may also be referred to herein as "coolant" or coolant 222. In some embodiments, 1% to 3% of the working fluid is transferred to coolant supply line 220 to cool components of compressor 202. The refrigerant is returned to the refrigeration circuit via a refrigerant return line 214 (e.g., an internal refrigerant return line) that directs the refrigerant toward the compressor 202 or the low-pressure line 220 (e.g., suction line 210) of the refrigerant circuit. As used herein, a “low-pressure line” of the compressor (e.g., compressor 202) refers to a refrigerant flow passage within the compressor or the main refrigeration circuit in which the compressor 202 is part, preceding and directing the refrigerant toward one or more impellers in the compressor stages (e.g., the first-stage impeller of the compressor). The low-pressure line 220 of the compressor 202 may include, for example, but not limited to, a passage extending between the inlet of the first stage of the compressor 202 and the first-stage impeller, the first-stage inlet of the compressor 202, and the suction line 210 connected to the first-stage inlet of the compressor 202.

[0038] The coolant used in cooling system 212 is suitably drawn from the low-temperature, high-pressure side of the main refrigeration circuit, downstream of condenser 204 and upstream of expansion device 206 (i.e., from the refrigerant line connecting condenser 204 and expansion device 206), or alternatively, from condenser 204. Drawing coolant from the main refrigeration circuit at this stage provides several advantages.

[0039] The pressure difference across the cooling circuit 300 of the cooling system 212—that is, the pressure difference between the high-pressure refrigerant leaving the condenser 204 and the low-pressure refrigerant entering the compressor 202 via the suction line 210—facilitates the driving of the refrigerant through the compressor 202 and back into the refrigeration circuit. The relatively low temperature of the refrigerant leaving the condenser 204, compared to the temperature of the refrigerant downstream of the main refrigeration circuit (e.g., leaving the evaporator 208 and / or the expansion device 206), contributes to improving the cooling capacity of the cooling system 212.

[0040] Reference Figure 4 and Figure 5The compressor cooling system 212 includes a compressor cooling circuit 300, which is used to cool the inlet coolant flow F 306 Supply to one or more components of compressor 100, such as motor 108, first bearing assembly 160 of first compression stage 124, and / or second bearing assembly 164 of second compression stage 126. Cooling circuit 300 includes inlet connection port 304 defined by compressor housing 102 and extending through its housing for directing coolant flow F 306 The coolant is introduced into the cooling circuit 300. The cooling circuit 300 includes a coolant inlet passage 306 that is fluidly connected to the inlet connection port 304. The coolant inlet passage 306 may be formed through at least partially through the compressor housing 102.

[0041] The compressor cooling circuit 300 also includes a coolant supply line 310 for supplying coolant from a coolant source 312 to an inlet connection port 304. In the illustrated embodiment, the coolant source 312 is a working fluid, such as coolant 222, drawn from the refrigeration system 200 via the supply line 220— Figure 3 As shown in the illustration, in the embodiment illustrated, the working fluid is drawn from the refrigerant circuit downstream of the condenser 204. However, the working fluid can be drawn from any suitable portion of the refrigerant circuit that enables the compressor cooling system 212 to function as described herein, such as downstream of the expansion device 206 or from the evaporator 208. In an alternative embodiment, the coolant source 312 can be any suitable coolant source for supplying any suitable coolant, such as a coolant separate from the working fluid.

[0042] The compressor cooling circuit 300 includes, for example, a flow control device 320 illustrated as a solenoid valve. The flow control device 320 is connected to the coolant supply line 310 and / or positioned upstream of the inlet connection port 304 and / or the coolant inlet passage 306 for controlling the flow of coolant through the cooling circuit 300. The compressor cooling circuit 300 may also include a controller 322 communicatively connected to the flow control device 320. The controller 322 can transmit one or more signals to the flow control device 320 to regulate flow parameters of the coolant supplied to the inlet connection port 304, such as velocity, mass flow rate, or pressure. In other words, the flow control device 320 regulates the inlet coolant flow F. 306 The flow parameters are controlled.

[0043] In some embodiments, the compressor cooling circuit 300 may include one or more coolant sensors 324 communicatively connected to the controller 322 for detecting coolant parameters. These coolant sensors 324 may be, for example, pressure sensors, temperature sensors, and / or speed sensors. In some embodiments, the controller 322 may use the received sensor data to determine one or more control signals to be transmitted to the flow control device 320 for, for example, adjusting the coolant parameters.

[0044] Additionally and / or alternatively, compressor 100 and / or compressor cooling circuit 300 also include one or more compressor sensors communicatively coupled to controller 322 for detecting parameters of compressor 100. For example, in some embodiments, compressor 100 includes temperature sensors (not shown) capable of determining the temperature of paired motor 108, first bearing assembly 160, second bearing assembly 164, and / or any other suitable component of compressor 100.

[0045] The inlet connection port 304 and the coolant inlet passage 306 may be axially positioned between the first impeller 106 and the second impeller 116 and / or axially positioned between the first bearing housing 162 and the second bearing housing 166. The inlet connection port 304 and the inlet passage 306 may be positioned substantially axially between the first axial end 144 and the second axial end 146 of the motor 108. In some embodiments, the inlet connection port 304 and the coolant inlet passage 306 are positioned axially closer to the second bearing assembly 164 and / or the second impeller 116 than to the first bearing assembly 160 and / or the first impeller 106. In some embodiments, the inlet connection port 304 and the coolant inlet passage 306 are arranged on the bottom or lower side 150 of the compressor 100 opposite to the upper side 152. For example, the inlet connection port 304 and the coolant inlet passage 306 may be positioned on the same side of the compressor 100 as the foot or mounting support 154 of the compressor 100. Coolant inlet passage 306 may extend approximately along a direction Z that is approximately perpendicular to the horizontal axis X, which is parallel to the longitudinal axis A of shaft 104. 104 .

[0046] Further reference Figure 5 and Figure 6The cooling circuit 300 also includes a cooling channel 350 fluidly connected to the inlet connection port 304 and / or the coolant inlet passage 306. In the illustrated embodiment, the cooling channel 350 is defined within the compressor housing 102 and spirally wound or extends around or around the motor 108 (e.g., the stator 394 of the motor 108). More specifically, the cooling channel 350 is defined along the inner surface of the compressor housing 102, such as the radial inner surface of the outer shell of the compressor housing 102. When mounted in the compressor housing 102, the cooling channel 350 opens to and communicates with the inner cavity of the compressor housing 102 and the motor 108 (e.g., the stator 394 of the motor 108). Furthermore, when the compressor 100 is assembled, the motor 108 forms the inner boundary 305 of the cooling channel 350, such as... Figure 4 As shown. For example, the outer surface 148 of motor 108 (e.g., stator 394 of motor 108) forms an inner boundary 305. Cooling channel 350 is along the direction of the horizontal axis X and along the longitudinal axis A of shaft 104. 104 Extending spirally along the entire axial length or total axial length L 350 The total axial length L of the cooling channel 350 350 It can be approximately the same axial length as motor 108 (e.g., stator 394 of motor 108).

[0047] Cooling channel 350 includes a first branch or first portion 360 and a second branch or second portion 362, each of which originates from or extends from the coolant inlet passage 306 and / or inlet connection port 304, such that the inlet coolant flow F 306 The coolant is diverted or separated between the first portion 360 and the second portion 362. The first portion 360 extends from the coolant inlet passage 306 and / or the inlet connection port 304 to the first outlet 370, and extends from the inlet connection port 304 in the direction of the first impeller 106 and / or the first bearing housing 162 (i.e., toward the first compression stage 124). The second portion 362 extends from the coolant inlet passage 306 and / or the inlet connection port 304 to the second outlet 372, and extends from the inlet connection port 304 in the direction of the second impeller 116 and / or the second bearing housing 166 (i.e., toward the second compression stage 126). Each of the first portion 360 and the second portion 362 has a corresponding axial length L. 360 and L 362 Their sum is the total axial length L of the cooling channel 350. 350 .

[0048] The first portion 360 and the second portion 362 also have corresponding first and second lengths. The first and second lengths refer to the path length of the corresponding first portion 360 or second portion 362, i.e., the length along which the fluid travels. In embodiments with a spiral cooling channel 350, as illustrated in the embodiment, the first and second lengths can be determined using the equation π * (number of turning portions) * (outer diameter - inner diameter) / 2. In some embodiments, the first portion 360 and the second portion 362 have the same number of turning portions per unit axial length, such that the cooling channel 350 extends along the entire axial length L. 350 It has a uniform helical winding portion. In some alternative embodiments, the first portion 360 and the second portion 362 have different numbers of turning portions per unit axial length. For example, the first portion 360 may have more turning portions per unit axial length than the second portion 362. Alternatively, the second portion 362 may have more turning portions per unit axial length than the first portion 360.

[0049] Part 360 and Part 362 each have a corresponding cross-sectional area A. 360 and A 362 .exist Figure 7 and Figure 8 As shown in the figure. In the illustrated embodiment, the cross-sectional area A 360 and A 362 They are approximately constant along their respective lengths, and they are approximately the same. For example, the cross-sectional area A 360 and A 362 These can vary from one another by 5% to 10%. Alternatively, the cross-sectional area A 360 and A 362 They can be different. For example, the cross-sectional area A of the first part is 360. 360 The cross-sectional area A of the second part 362 can be smaller. 362 Or the cross-sectional area A of the second part 362 362 The cross-sectional area A can be smaller than 360 of the first part. 360 In the illustrated embodiment, cross-sectional region A 360 and A 362 Its shape is roughly semi-circular, but the cross-sectional area A 360 and A 362 It can have any suitable cross-sectional shape that enables the compressor cooling circuit 300 to function as described herein.

[0050] Inlet coolant flow F 306Coolant is introduced into the cooling channel 350 through a single coolant inlet passage 306 and / or a single inlet connection port 304. For example, the coolant inlet passage 306 and / or inlet connection port 304 is the only coolant inlet passage and / or the only inlet connection port. The coolant inlet passage 306 is connected to the cooling channel 350 in a manner substantially perpendicular to the cooling channel 350, such that the cooling circuit 300 includes a generally U-shaped, Y-shaped, or T-shaped branch 340. The branch 340 directs the inlet coolant flow F... 306 The first coolant flow F is divided into the first section 360 and guided into the first coolant stream. 360 and the second coolant flow F directed into the second section 362 362 .

[0051] First coolant flow F 360 The first coolant flows through the first section 360 in the first direction, and the second coolant flow F 362 The coolant flows through the second section 362 in a second direction opposite to the first direction. For example, the first coolant flow F 360 It can flow clockwise through the first section 360, and the second coolant flow F 362 It flows counterclockwise through the second part 362.

[0052] The first outlet 370 will deliver the first coolant flow F 360 The coolant is released from the first portion 360 to or near the first compression stage 124, for example, to the first bearing housing 162, the first impeller 106, and / or the first shaft end 140. The second outlet 172 delivers the second coolant flow F. 362 Released from the second part 362 to the second compression stage 126, for example to the second bearing housing 166, the second impeller 116 and / or the second shaft end 142.

[0053] Reference Figures 7 to 8 Each of the first exit 370 and the second exit 372 has a first exit area A. 370 Second export area A 372 In the illustrated embodiment, the second outlet area A 372 Greater than the area of ​​the first exit A 370 In other embodiments, the second exit area A 372 It can be smaller than the area of ​​the first exit, A. 370 Or the area of ​​the first exit, A 370 Second export area A 372 They can be the same. The first outlet 370 has a length L extending between the first axial end 374 and the second axial end 376. 370 and width W 370The second outlet 372 has a length L extending between the first axial end 378 and the second axial end 380. 372 and width W 372 In the illustrated embodiment, the length L 370 Shorter than length L 372 In other embodiments, the length L 370 It can be longer than length L 372 or length L 370 L 372 They can be the same.

[0054] In the illustrated embodiment, the width W 370 and width W 372 Generally the same, but in other implementations, the width W 370 It can be greater than or less than the width W 372 The first exit 370 and the second exit 372 each have a corresponding exit depth D. 370 and D 372 In the illustrated embodiment, the outlet depth D 370 and export depth D 372 Broadly the same, but in other implementations, the outlet depth D 370 It can be greater than or less than the outlet depth D 372 .

[0055] Further reference Figure 4 and Figure 5 In some implementations, the first outlet 370 (in) Figure 4 The first outlet 370 (not visible in the image) and the second outlet 372 are axially aligned with the first axial end 144 and the second axial end 146 of the motor 108 (e.g., the stator 394 of the motor 108), respectively. For example, the first axial end 144 may be aligned between the first axial end 376 and the second axial end 374 of the first outlet 370, and the second axial end 146 may be aligned between the first axial end 378 and the second axial end 380 of the second outlet 372. In some embodiments, the first outlet 370 and the second outlet 372 are axially positioned outside the motor 108 (e.g., the stator 394 of the motor 108). The first outlet and the second outlet are positioned to direct a first coolant flow F 360 Second coolant flow F 362 It is axially released to the outside of the motor 108 (e.g., the stator 394 of the motor 108).

[0056] The first outlet 372 and the second outlet 370 may have different radial positions. For example, the first outlet 370 has a radial position that is substantially aligned with the upper side 152 of the compressor 100, and the second outlet 372 is radially offset relative to the first outlet 370 by approximately 90°. In some embodiments, the second outlet 372 may be radially offset relative to the first outlet 370 by 45° to 120°.

[0057] In the embodiments described herein, the compressor cooling circuit 300 includes a single inlet connection port 304 and a single coolant inlet passage 306, allowing coolant to be supplied to the cooling circuit 300 using only a single supply line 310 to deliver coolant to multiple components of the compressor 100. Since only a single coolant supply line 310 needs to be connected to the inlet connection port 304, the single inlet connection port 304 reduces installation time and cost. Additionally, the single inlet connection port 304 allows a single flow control device 320 to regulate the flow of coolant supplied to the inlet connection port 304. Furthermore, the single inlet connection port 304 and the single coolant supply line 310 reduce the overall footprint and simplify compressor inspection and maintenance, which is particularly advantageous for compressor consumers or end users.

[0058] The implementation of the compressor cooling circuit 300 allows for the selective distribution of refrigerant throughout the compressor, which can be achieved with only a single flow control device 320. For example, one or more structural features of the first section 360 and the second section 362 cause selective distribution of refrigerant between the first section 360 and the second section 362. For example, one or more structural features of the first section 360 and the second section 362 can be designed to selectively and passively control the first refrigerant flow F exiting the first outlet 370 of the first section 360. 360 The amount and / or flow rate of the second coolant flow F exiting the second outlet 372 of the second section 362. 362 The amount and / or flow rate of refrigerant. In the embodiments described herein, these features are passive features such as structural elements that allow refrigerant to be distributed between the first outlet 370 and the second outlet 372 without the need for additional flow control devices and / or complex control systems and associated algorithms.

[0059] In an example implementation, the structural features of the first portion 360 and the second portion 362 cause the coolant to be preferentially guided to the second portion 362 and exit from the second outlet 372, compared to the amount or flow rate of coolant directed to the first portion 360 and exiting from the first outlet 372. For example, the second coolant flow F exiting the second outlet 372... 362 The second quantity and / or the second flow rate is greater than the first coolant flow F leaving the first outlet 370.360 The first quantity and / or first flow rate. In some embodiments, for example, structural features of the first portion 360 and the second portion 362 cause the inlet coolant flow F 350 The flow is split into a second coolant flow F that allows the flow to pass through the second section 362. 362 For the inlet coolant flow F 350 55% to 60%, and flows through the first coolant flow F in the first section 360. 360 For the inlet coolant flow F 350 40% to 45%. In some embodiments, the structural features of the first portion 360 and the second portion 362 cause the F flowing through the second portion 362 or exiting the second outlet 372 to... 362 The second flow rate is greater than the flow rate through the first section 360 or exiting the first outlet 370. 360 The first flow rate. In some implementations, the second flow rate may be 45% to 55%, 40% to 60%, or 49% to 51% greater than the first flow rate.

[0060] The first part 360 and the second part 362 each have a resistance to the flow of fluid along the respective first part 360 or second part 362, or a flow resistance value or flow resistance coefficient associated with that resistance. A higher flow resistance coefficient is associated with a lower flow rate or quantity of coolant, and a lower flow resistance coefficient is associated with a higher flow rate or quantity of coolant.

[0061] As those skilled in the art will understand, the flow resistance coefficient depends largely on the geometry and construction of the channel, particularly the channel length, the cross-sectional area and / or diameter of the channel, the coefficient of friction of the surfaces defining the channel, and the size and shape of the outlet. For example, for a channel with a fixed cross-sectional area, a shorter flow path length and / or a larger outlet will result in lower flow resistance. Similarly, a higher flow resistance coefficient can be associated with a longer flow path length and / or a smaller outlet. The flow resistance coefficient can be determined using various equations for calculating flow rates, or alternatively, it can be determined empirically, for example, during calibration or design processes. Furthermore, in the context of this disclosure, the relative flow resistance coefficients of the first portion 360 and the second portion 362 can be used as a representative measure of the relative flow rates of coolant along the first portion 360 and the second portion 362, and the resulting amount of coolant delivered along the first portion 360 and the second portion 362. Therefore, the flow resistance coefficients of the first portion 360 and the second portion 362 can be determined or analyzed independently of the operating characteristics of the compressor 100 (e.g., differential pressure, specific gravity of the refrigerant, etc.) to assess the relative flow rate and / or quantity along the first portion 360 and the second portion 362.

[0062] The first portion 360 has a first flow resistance coefficient, which is different from the second flow resistance coefficient of the second portion 362. As described above, the first flow resistance coefficient is related to the first coolant flow F exiting the first outlet 370. 360 The amount and / or flow rate are inversely proportional. Similarly, the second drag coefficient is inversely proportional to the second coolant flow F exiting the second outlet 372. 362 The amount and / or flow rate are inversely proportional. In the illustrated embodiment, the first flow resistance coefficient is greater than the second flow resistance coefficient. For example, the first portion 360 may have a larger first length and area A compared to the second portion 362. 362 Compared to having a smaller cross-sectional area A 360 and export area A 372 Compared to A, which has a smaller export area 370 The first part 360 has a larger coefficient of friction than the second part 362, has more turning sections per unit length than the second part 362, has a larger flow path volume (cross-sectional area * length), or any combination thereof. Therefore, the flow rate and / or amount of coolant transported along the first part 360 (and thus to the first compression stage 124) is less than the flow rate and / or amount of coolant transported along the second part 362 (and thus to the second compression stage 126).

[0063] Further reference Figure 4 In the first coolant flow F 360 leave Figure 4 After the first invisible outlet 370, the first coolant flow F 360 The coolant flows within the compressor housing 102 toward and around the first bearing housing 162 and the first bearing assembly 160, for example, between the first bearing assembly 160 and the shaft 104. In the second coolant flow F... 362 After leaving the second exit 372, the second coolant flow F 362 The flow is within the compressor housing 102 toward the second bearing housing 166 and around the second bearing assembly 164, for example, between the second bearing assembly 164 and the shaft 104.

[0064] In the embodiments described herein, the first coolant flow F 360 Upon exiting the first outlet 370, it is directly conveyed to the first bearing housing 162. For example, the first coolant flow F 360 The coolant is not used to cool other components of the compressor 100 before being conveyed to the first bearing housing 162. Additionally, in some embodiments described herein, the first coolant flow F... 360 It is released near the first bearing housing 162, therefore the first coolant flow F 360It cannot pass through other parts of the compressor 100 before reaching the first bearing housing 162.

[0065] In the embodiments described herein, the second coolant flow F 362 Upon exiting the second outlet 370, it is directly conveyed to the second bearing housing 166. For example, the second coolant flow F 362 The coolant is not used to cool other components of the compressor 100 before being conveyed to the second bearing housing 166. Additionally, in some embodiments described herein, the second coolant flow F... 362 It is released near the second bearing housing 166, therefore the second coolant flow F 360 It cannot pass through other parts of the compressor 100 before reaching the second bearing housing 166.

[0066] Refrigeration system 200 includes a return coolant flow path 396, the return coolant flow path 396 being a first coolant flow path F 360 Second coolant flow F 362 After cooling the first bearing 160 and the second bearing 164 respectively, the first coolant flow F 360 Second coolant flow F 362 Both return. The return flow paths include a first return flow path 392 after cooling the first bearing assembly 160 and a second return flow path 390 returning from the second bearing assembly 164 and traveling along the shaft 104 through the motor 108 (e.g., the stator 394 of the motor 108). The return coolant flow path 390 may include a return passage 396 for returning the return flow paths 392 and 390 to the first compression stage 124.

[0067] Reference Figure 9 In some embodiments, the cooling circuit 300 includes a plurality of inlet connection ports 304 defined by the compressor housing 102, and a plurality of coolant inlet passages 306 fluidly connected to one of the inlet connection ports 304. For example, the cooling circuit 300 may include a first inlet connection port 410 and a second inlet connection port 420, the first inlet connection port 410 being fluidly connected to a first coolant inlet passage 412 for directing a first coolant flow F 410 The second inlet connection port 420 is fluidly connected to the second coolant inlet passage 422, which is introduced into the cooling circuit 300, for introducing the second coolant flow F. 420 It is introduced into the cooling circuit 300.

[0068] exist Figure 9 In the illustrated embodiment, the first coolant inlet passage 412 and the second coolant inlet passage 422 are fluidly connected to a cooling channel 350 extending spirally around the motor 108. Figure 9 In the illustrated embodiment, the cooling channel 350 includes a first portion 430, a second portion 432, and a third portion 434 extending between the first portion 430 and the second portion 432. The first portion 430 extends from a first coolant inlet passage 412 to a first outlet 370, and the second portion 432 extends from a second coolant inlet passage 422 to a second outlet 372. The third portion 434 extends between the first coolant inlet passage 412 and the second coolant inlet passage 422 and is fluidly connected to the first coolant inlet passage 412 and the second coolant inlet passage 422.

[0069] In some embodiments, the first coolant flow F 410 Part of the second coolant flow F 420 A portion can flow into the third section 434 for combination to form the third coolant flow F. 434 The third coolant flow F 434 It can have a lower flow rate to form a near-static coolant cavity within the third section 434. In some cases, the third coolant flow F 434 It can flow towards the second section 432. In some cases, the third coolant flow F 434 It can flow toward the first section 430. In the illustrated embodiment, most of the first coolant flow F 410 The flow passes through the first section 430 and exits through the first outlet 370, thus carrying away most of the first coolant flow F. 410 The second coolant flow F is delivered to the first bearing assembly 160, and most of the second coolant flow F 420 The flow passes through the second section 432 and exits through the second outlet 372, thus diverting most of the second coolant flow F. 420 It is delivered to the second bearing assembly 164. In other words, only a small portion of the first coolant flow F... 410 and a small portion of the second coolant flow F 420 The coolant is transferred to the third portion 434. The third portion 434 is axially positioned to align with the motor 108 for cooling components of the motor 108. The third portion 434 may be shorter than either or both of the first portion 430 and the second portion 432. In some embodiments, the third portion 434 includes a single-channel deflector or fewer than a single-channel deflector. In the illustrated embodiment, due to the third coolant flow F... 434 The amount is less than the first coolant flow F flowing through the corresponding first section 430 and second section 432. 410 The amount and the second coolant flow F 412 Any of the quantities, such that most of the total inlet coolant flow F 306It is conveyed to the first bearing assembly 160 and the second bearing assembly 164, and the total inlet coolant flow F is less. 306 Or a small number of total inlet coolant flows F 306 For example, the third coolant flow F 464 The components are conveyed to cool the motor 108, thus improving the cooling of the compressor 100.

[0070] In some embodiments, the lengths of the first portion 430 and the second portion 432 are approximately the same. In some embodiments, the first portion 430 and the second portion 432 may include the same number of channel deflectors surrounding the motor 108. In some embodiments, the second portion 432 is longer than the first portion 430. In some alternative embodiments, the second portion 432 includes more channel deflectors surrounding the motor 108 than the channel deflectors of the first portion 430. In some alternative embodiments, the first portion 430 is longer than the second portion 432. In some alternative embodiments, the first portion 430 includes more channel deflectors surrounding the motor 108 than the channel deflectors of the second portion 432.

[0071] In the illustrated embodiment, the arrangement of the first inlet connection port 410 and the first coolant inlet passage 412 relative to the first outlet 370 shortens the distance of the first portion 430, thereby causing the coolant fluid flow, for example, most of the first coolant flow F, to be... 430 It is delivered to the first bearing assembly 160 more quickly. For example, the first coolant inlet passage 412 is positioned closer to the first outlet 270 than the second coolant inlet passage 422. Similarly, the arrangement of the second inlet connection port 420 and the second coolant inlet passage 422 relative to the second outlet 372 shortens the distance of the second portion 432, thereby causing the coolant fluid flow, such as the majority of the second coolant flow F, to be more efficient. 432 The coolant is delivered to the second bearing assembly 164 more quickly. For example, the second coolant inlet passage 422 is located closer to the second outlet 372 than the first coolant inlet passage 412. Each of the first coolant inlet passage 412 and the second coolant inlet passage 422 is fluidly connected to the coolant source 312 via corresponding first coolant supply lines 450 and 452 disposed outside the compressor housing 102. In some embodiments, the length of the first coolant supply line 450 may differ from the length of the second coolant supply line 452. In some embodiments, the length of the first coolant supply line 450 is approximately the same as the length of the second coolant supply line 452. In some embodiments, the supply line 310 is fluidly connected to a branch line 460, which directs the total inlet coolant flow F 306Distribution occurs between the first coolant supply line 450 and the second coolant supply line 452.

[0072] The relative lengths of the first coolant supply line 450 and the second coolant supply line 452 can be selected during installation, for example, by the consumer or the technician responsible for installing the compressor 100, which may affect the total resistance of the first section 430 and the second section 432. The arrangement of the dual inlet connection ports 410, 420 relative to the first outlet 370 and the second outlet 372, and the third coolant flow F within the third section 434... 434 The formation will mitigate the difference in supply line length chosen by the consumer or user by delivering most of the coolant inlet supply to the first bearing assembly 160 and the second bearing assembly 164.

[0073] The flow control device 320 may be located upstream of either or both of the first inlet connection port 410 and the second inlet connection port 420 for controlling the flow of coolant through the cooling circuit 300. For example, the flow control device 320 may be upstream of the branch section 460 and upstream of both the first coolant supply line 450 and the second coolant supply line 452 connected to the coolant supply line 310. In some alternative embodiments, the cooling circuit 300 is fluidly connected to one or more of the flow control devices 320. For example, in some alternative embodiments, the cooling circuit 300 includes a first flow control device in the flow control device 320 fluidly connected to the first coolant supply line 450, and a second flow control device in the flow control device 320 fluidly connected to the second coolant supply line 452.

[0074] The first section 430, the second section 432, and the third section 434 each have a flow resistance value or flow resistance coefficient, which represents the resistance to or associated with the flow of fluid along the respective first section 430, second section 432, and third section 434. As mentioned above, a higher flow resistance coefficient is associated with a lower flow rate or quantity of coolant, and a lower flow resistance coefficient is associated with a higher flow rate or quantity of coolant. Furthermore, the flow resistance coefficient depends to a large extent on the geometry and construction of the channels, particularly the channel length, the cross-sectional area and / or diameter of the channels, the coefficient of friction of the surfaces defining the channels, and the size and shape of the outlet, etc.

[0075] In some embodiments, the first portion 430 has a first flow resistance coefficient that is approximately the same as the second flow resistance coefficient of the second portion 432. In some embodiments, the first flow resistance coefficient differs from the second flow resistance coefficient. For example, the first flow resistance coefficient may be greater than the second flow resistance coefficient. For example, the first portion 430 may have a greater length, a smaller cross-sectional area, and a smaller outlet area A compared to the second portion 432. 372 Compared to A, which has a smaller export area 370 The first part 430 has a larger coefficient of friction than the second part 432, has more turning points per unit length than the second part 432, has a larger flow path volume (cross-sectional area * length), or any combination thereof. Therefore, the flow rate and / or amount of coolant transported along the first part 430 (and thus to the first compression stage 124) is less than the flow rate and / or amount of coolant transported along the second part 432 (and thus to the second compression stage 126).

[0076] For example, the structural features of the first part 430, the second part 432, and the third part 434 cause most of the inlet coolant flow F to be diverted. 306 The flow passes through the second section 432. In some embodiments, the structural features of the first section 430, the second section 432, and the third section 434 result in 60% to 50% of the total inlet coolant flow F 306 (For example, the total coolant flow delivered to cooling circuit 300) flows along the second section 432, and 40% to 50% of the total inlet coolant flow F 306 The coolant flows along the first section 430. In some embodiments, the structural features of the first section 430, the second section 432, and the third section 434 result in 55% to 45% of the total inlet coolant flow F 306 Flowing along the second section 432, and 45% to 55% of the total inlet coolant flow F 306 The coolant flows along the first section 430. In some embodiments, the structural features of the first section 430, the second section 432, and the third section 434 result in 50% of the total inlet coolant flow F 306 Flowing along section 432, and 50% of the total inlet coolant flow F 306 Flow along section 430.

[0077] In some embodiments, the structural features of the first portion 430, the second portion 432, and the third portion 434 cause the F flowing through the second portion 432 or exiting the second outlet 372 to 420 The second flow rate is greater than the flow rate through the first section 430 or exiting the first outlet 370. 410The first flow.

[0078] The first inlet connection port 410 and the second inlet connection port 420, as well as the first coolant inlet passage 412 and the second coolant inlet passage 422, are all arranged on the bottom or lower side 150 of the compressor 100 opposite to the upper side 152. The first inlet connection port 410 and the second inlet connection port 420 can be arranged adjacent to each other, for example, axially spaced 20 mm to 30 mm apart. The relative positions of the first inlet connection port 410 and the second inlet connection port 420 improve the installation process by allowing for shorter coolant supply lines 450, 452 that only need to be connected to one side of the compressor 100.

[0079] When elements or embodiments of this disclosure are introduced, the terms “a,” “an,” “the,” and “the” are intended to indicate the presence of one or more elements. The terms “comprising,” “including,” “containing,” and “having” are intended to be inclusive and mean that additional elements may be present in addition to the listed elements. Terms indicating a particular orientation (e.g., “top,” “bottom,” “side,” etc.) are used for ease of description and do not require any particular orientation of the described item.

[0080] Since various changes can be made to the above-described constructions and methods without departing from the scope of this disclosure, it is intended that all content contained in the above description and shown in the accompanying drawings should be interpreted as illustrative and not restrictive.

Claims

1. A compressor system, comprising: Compressor housing; A shaft, which is rotatably supported within the compressor housing by a first bearing and a second bearing; A first impeller is operably connected to the shaft at a first end of the shaft; A second impeller is operably connected to the shaft at a second end of the shaft; A motor, which is operably connected to the shaft between the first bearing and the second bearing; as well as Cooling circuit, the cooling circuit comprising: A coolant inlet passage, defined by the compressor housing, for introducing an inlet coolant flow into the cooling circuit; and A cooling passage defined by the compressor housing and fluidly connected to the coolant inlet passage, wherein the cooling passage extends spirally around the motor and includes a first portion and a second portion, wherein each of the first portion and the second portion extends from the coolant inlet passage to a corresponding first outlet and second outlet, such that the inlet coolant flow is divided into a first coolant flow along the first portion and a second coolant flow along the second portion.

2. The compressor system according to claim 1, wherein, The flow rate of the second coolant stream is greater than the flow rate of the first coolant stream.

3. The compressor system according to claim 1, wherein, 55% to 60% of the inlet coolant flow flows along the second section, and 40% to 45% of the inlet coolant flow flows along the first section.

4. The compressor system according to claim 1, wherein, The length of the first part is greater than the length of the second part.

5. The compressor system according to claim 1, wherein, The length of the first portion is between 55% and 65% of the total length of the cooling channel.

6. The compressor system according to claim 1, wherein, Each of the first and second portions includes a plurality of channel steering sections around the motor, wherein the first portion includes more channel steering sections than the second portion.

7. The compressor system according to claim 6, wherein, The area of ​​the first exit of the first exit is smaller than the area of ​​the second exit of the second exit.

8. The compressor system according to claim 6, wherein, The area of ​​the second exit is at least 50% larger than the area of ​​the first exit of the first exit.

9. The compressor system according to claim 1, wherein, The coolant inlet passage is the only coolant inlet passage in the cooling circuit.

10. The compressor system according to claim 1, wherein, The coolant stream exiting the first outlet is delivered to the first bearing, and the coolant stream exiting the second outlet is delivered to the second bearing.

11. A compressor system, comprising: Compressor housing; A shaft, which is rotatably supported within the compressor housing by a first bearing and a second bearing; A first impeller is operably connected to the shaft at a first end of the shaft; A second impeller is operably connected to the shaft at a second end of the shaft; A motor, which is operably connected to the shaft between the first bearing and the second bearing; as well as Cooling circuit, the cooling circuit comprising: A coolant inlet passage, defined by the compressor housing, for introducing an inlet coolant flow into the cooling circuit; and A cooling passage, defined by the compressor housing and fluidly connected to the coolant inlet passage, wherein the cooling passage extends helically around the motor, the cooling passage comprising a first portion and a second portion, wherein each of the first portion and the second portion extends from the coolant inlet passage to a corresponding first outlet and second outlet, such that the inlet coolant flow is divided into a first coolant flow along the first portion and a second coolant flow along the second portion, wherein each of the first portion and the second portion has a corresponding flow resistance coefficient, and wherein the flow resistance coefficient of the first portion is greater than the flow resistance coefficient of the second portion.

12. The compressor system according to claim 11, wherein, Each of the flow resistance coefficients depends on the cross-sectional area of ​​the corresponding first or second portion, the length of the corresponding first or second portion, the outlet area of ​​the corresponding first or second portion, and the friction coefficient of the corresponding first or second portion.

13. The compressor system according to claim 11, wherein, The flow rate of the second coolant stream is greater than the flow rate of the first coolant stream.

14. The compressor system according to claim 11, wherein, 55% to 60% of the inlet coolant flow flows along the second section, and 40% to 45% of the inlet coolant flow flows along the first section.

15. The compressor system according to claim 11, wherein, The length of the first part is greater than the length of the second part.

16. The compressor system according to claim 11, wherein, The length of the first portion is between 55% and 65% of the total length of the cooling channel.

17. The compressor system according to claim 11, wherein, Each of the first and second portions includes a plurality of channel steering sections around the motor, wherein the first portion includes more channel steering sections than the second portion.

18. The compressor system according to claim 11, wherein, The area of ​​the first exit of the first exit is smaller than the area of ​​the second exit of the second exit.

19. The compressor system according to claim 11, wherein, The coolant stream exiting the first outlet is delivered to the first bearing, and the coolant stream exiting the second outlet is delivered to the second bearing.

20. A compressor system, comprising: Compressor housing; A shaft, which is rotatably supported within the compressor housing by a first bearing and a second bearing; A first impeller is operably connected to the shaft at a first end of the shaft; A second impeller is operably connected to the shaft at a second end of the shaft; A motor, which is operably connected to the shaft between the first bearing and the second bearing; as well as Cooling circuit, the cooling circuit comprising: A coolant inlet passage, defined by the compressor housing, for introducing an inlet coolant flow into the cooling circuit; and A channel, which is fluidly connected to the coolant inlet passage, wherein the channel is at least partially wound around the motor, the channel comprising a first portion and a second portion, and wherein each of the first portion and the second portion extends from the coolant inlet passage to a corresponding first outlet and a second outlet, such that the inlet coolant flow is divided into a first coolant flow along the first portion and a second coolant flow along the second portion, wherein the cross-sectional area of ​​the first portion is substantially the same as the cross-sectional area of ​​the second portion, and wherein the first portion has a first length longer than a second length of the second portion.

Images