Compressor cooling system and method including a refrigerant damping chamber

Abstract

The refrigeration system includes a compressor, an evaporator connected to the compressor's low-pressure line, a condenser, an expansion device, and a refrigeration circuit. The refrigeration circuit includes at least one refrigerant supply line for delivering refrigerant toward the compressor, at least one refrigerant flow path defined by the compressor housing for delivering refrigerant toward the compressor's motor, a refrigerant return line for delivering refrigerant toward the compressor's low-pressure line, and a damping chamber located between the refrigerant return line and the compressor's low-pressure line. The damping chamber includes a damping chamber inlet that allows refrigerant from the refrigerant return line to enter the damping chamber volume and a damping chamber outlet that allows refrigerant in the damping chamber volume to enter the compressor's low-pressure line.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims priority to U.S. Patent Application No. 18 / 186,386, filed March 20, 2023, the disclosure of which is incorporated by reference in its entirety.

[0002] [Technical field] The field of this disclosure relates generally to refrigeration systems, and more particularly to providing cooling to a compressor within a refrigeration system using refrigerant drawn from the high pressure side of the refrigeration system. [Background technology]

[0003] Dynamic compressors, including centrifugal compressors, are commonly used in process industries and HVAC (heating, ventilation, and air conditioning) systems. The compressor is typically connected to a motor via a shaft that supports multiple compression stages. A drive controls the motor to rotate the compression stages at selected rotational speeds and load conditions to compress the refrigerant to a specific demand. The motor speed and load can be controlled to operate the compressor under a wide range of operating conditions.

[0004] During operation, the drive, motor, and compressor bearings can reach high temperatures, which, if left unaddressed, can increase the risk of mechanical failure due to overheating. Existing refrigeration systems can divert a relatively low-temperature refrigerant from the main refrigeration circuit for use as a coolant to cool the compressor components. The refrigerant is routed through the compressor housing, where it provides cooling to the compressor components. The refrigerant is then routed toward the low-pressure side of the compressor, where it mixes with low-pressure refrigerant entering the compressor via the suction line of the main refrigeration circuit. The low-pressure refrigerant and refrigerant are routed through compression stages and compressed simultaneously.

[0005] In some known systems, refrigerant is diverted from the high-pressure side of the main refrigeration circuit (e.g., from the section between the condenser and the expansion valve). Using refrigerant withdrawn from the high-pressure side of the main refrigeration circuit as refrigerant can disrupt the flow of low-pressure refrigerant through the main refrigeration circuit and into the low-pressure side of the compressor. This can reduce the performance, efficiency, and / or life of the compressor. Therefore, there is a need for a compressor system that facilitates using refrigerant withdrawn from the high-pressure side of the refrigeration system to cool the compressor while also reducing or eliminating the possibility of the refrigerant disrupting the flow of refrigerant on the low-pressure side of the compressor.

[0006] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and / or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. As such, it should be understood that these statements are to be construed in this light, and not as admissions of prior art. Summary of the Invention

[0007] One aspect is a refrigeration system including a compressor, an evaporator, a condenser, an expansion device, and a refrigeration circuit. The compressor includes a housing, a shaft rotatably supported within the housing, an impeller connected to the shaft, and a motor operably connected to the shaft. The evaporator is connected to a low-pressure line of the compressor. The refrigeration circuit includes: at least one refrigerant supply line for delivering refrigerant from one of the condenser and a refrigerant line connected between the condenser and the expansion device toward the housing; at least one refrigerant flow path defined by the housing for receiving refrigerant from the at least one refrigerant supply line and delivering the refrigerant toward the motor; a refrigerant return line for delivering refrigerant from the at least one refrigerant flow path toward the low-pressure line of the compressor; and a damping chamber located between the refrigerant return line and the low-pressure line of the compressor. The damping chamber includes a damping chamber inlet connected to the coolant return line to allow coolant to enter the damping chamber volume from the coolant return line, and a damping chamber outlet connected to the compressor low pressure line to allow coolant in the damping chamber volume to enter the compressor low pressure line.

[0008] Another aspect is a compressor system including a compressor and a cooling circuit. The compressor includes a housing defining a compressor inlet, a shaft rotatably supported within the housing, an impeller connected to the shaft, and a motor operably connected to the shaft. The compressor has a passageway extending between the housing, the compressor inlet, and the impeller. The cooling circuit includes at least one coolant flow path defined by the housing for receiving and delivering coolant toward the motor, a coolant return line for delivering coolant from the at least one coolant flow path toward the passageway, and a damping chamber located between the coolant return line and the passageway. The damping chamber includes a damping chamber inlet connected to the coolant return line to allow coolant to enter the damping chamber volume from the coolant return line, and a damping chamber outlet connected to the passageway to allow coolant in the damping chamber volume to enter the passageway at discrete angular flow directions.

[0009] Another aspect is a method of operating a refrigeration system. The refrigeration system includes a compressor, an evaporator, a condenser, and an expansion device. The compressor includes a housing, a shaft rotatably supported within the housing, an impeller connected to the shaft, and a motor operably connected to the shaft. The method includes compressing a refrigerant using the compressor to produce compressed refrigerant, condensing the compressed refrigerant using a condenser to produce compressed condensed refrigerant, expanding a first portion of the compressed condensed refrigerant using the expansion device to produce uncompressed condensed refrigerant, evaporating the uncompressed condensed refrigerant using an evaporator to produce uncompressed vapor refrigerant, and routing the uncompressed vapor refrigerant toward a low-pressure line of the compressor. The method also includes diverting a second portion of the compressed condensed refrigerant toward the housing of the compressor to provide cooling to the motor, routing the second portion of the compressed condensed refrigerant toward the low-pressure line of the compressor, and mixing the second portion of the compressed condensed refrigerant with the uncompressed vapor refrigerant in the low-pressure line of the compressor. Mixing a second portion of the compressed condensed refrigerant with the uncompressed vapor refrigerant in the low pressure line of the compressor includes intersecting the uncompressed vapor refrigerant with the second portion of the compressed condensed refrigerant in the low pressure line at a discrete angular flow direction.

[0010] Various refinements of the features described with respect to the above-described aspects of the present disclosure exist. Additional features may be incorporated into the above-described aspects of the present disclosure as well. These refinements and additional features may exist individually or in any combination. For example, the various features discussed below in connection with any of the illustrated embodiments of the present disclosure may be incorporated, alone or in any combination, into any of the above-described aspects of the present disclosure. [Brief explanation of the drawings]

[0011] The following figures illustrate various aspects of the present disclosure. [Figure 1] FIG. 1 is a schematic diagram of an exemplary refrigeration system. [Figure 2] FIG. 2 is a schematic diagram of an exemplary compressor system for use with the exemplary refrigeration system shown in FIG. 1. [Figure 3] 3 is a perspective view of an exemplary compressor for use in the refrigeration system shown in FIG. 1 and the compressor system shown in FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view of the compressor shown in FIG. 3 taken along line 3-3. [Figure 5] 3 is a cross-sectional view of another exemplary compressor for use in the refrigeration system shown in FIG. 1 and the compressor system shown in FIG. 2. [Figure 6] FIG. 6 is an enlarged view of the portion of the compressor shown in FIG. 5 indicated by cross section C400. [Figure 7] FIG. 6 is an exploded view of an exemplary inlet guide vane arrangement for use with the compressor shown in FIG. 5.

[0012] Corresponding reference characters indicate corresponding parts throughout the drawings. DETAILED DESCRIPTION OF THE INVENTION

[0013] Although the embodiments are described with respect to a centrifugal compressor, they may also be applicable to other types of compressors. The bearings, motor, and drive of a dynamic compressor may be cooled using a refrigerant. The refrigerant is drawn from the high-pressure side of a main refrigeration circuit (e.g., a refrigeration loop used in an HVAC (heating, ventilation, and air conditioning) system). The refrigerant is routed from the high-pressure side of the main refrigeration circuit toward and through the compressor housing, providing cooling to the components housed therein. The refrigerant is then routed to a damping chamber before entering the compressor's low-pressure line. The damping chamber includes a damping chamber inlet that allows the refrigerant to enter the damping chamber volume and a damping chamber outlet connected to the low-pressure line to allow the refrigerant in the damping chamber volume to enter the low-pressure line. The flow of refrigerant into the low-pressure line is distributed across appropriately configured (e.g., sized, shaped, and positioned) damping chamber outlets so that the refrigerant enters the low-pressure line in multiple (i.e., two or more) discrete angular flow directions. Distributing the refrigerant flow across the damping chamber outlets and into the low-pressure lines facilitates reducing or eliminating the ability of refrigerant intersecting the main refrigerant flowing through the low-pressure lines to disrupt the flow of the main refrigerant (e.g., create turbulence in the low-pressure lines), thereby promoting improved compressor performance, efficiency, and life.

[0014] 1 is a schematic diagram of an exemplary refrigeration system 100. Refrigeration system 100 includes a compressor 102, a condenser 104, an expansion device 106 (e.g., an expansion valve, an orifice, a capillary tube), and an evaporator 108. Compressor 102 may suitably be a centrifugal compressor (e.g., centrifugal compressor 202 shown in FIG. 2). Refrigeration system 100 may include additional or other components other than those shown and described with reference to FIG. 1 without departing from the scope of the present disclosure.

[0015] During operation, the compressor 102 receives a working fluid, such as a refrigerant, as a low-pressure gas through a suction line 110. The compressor 102 compresses the low-pressure refrigerant gas, thereby increasing the temperature and pressure of the refrigerant. The compressed, high-temperature refrigerant exiting the compressor 102 is directed toward and passes through a condenser 104, where the refrigerant is condensed into a high-pressure liquid or a high-pressure liquid-gas mixture. The compressed, condensed refrigerant exiting the condenser 104 is directed toward and passes through an expansion device 106, which expands the refrigerant, thereby reducing the refrigerant's pressure. The expanded (or "uncompressed") refrigerant exiting the expansion device 106 may become a gas or a gas-liquid mixture after passing through the expansion device 106. The uncompressed refrigerant exiting the expansion device 106 is directed toward and passes through an evaporator 108. The evaporator 108 may include a heat exchanger, where a relatively high-temperature fluid circulating through the heat exchanger is cooled by the uncompressed refrigerant fluid. The uncompressed refrigerant fluid is evaporated to a gas in the evaporator 108. The uncompressed refrigerant gas exiting the evaporator 108 is pumped back towards the compressor 102 via suction line 110 where the working fluid is compressed again and the process repeats.

[0016] The exemplary refrigeration system 100 includes a compressor refrigeration system 112 that draws a working fluid (e.g., refrigerant) from a portion of a main refrigeration circuit (i.e., a refrigeration loop in which the working fluid is compressed using a compressor 102, condensed using a condenser 104, expanded using an expansion device 106, and evaporated using an evaporator 108). The working fluid used in the refrigeration system 112 is diverted from the main refrigeration circuit and routed toward the compressor 102 through a refrigerant supply line 116 to cool components of the compressor 102, such as the motor and bearings of the compressor 102. The working fluid used in the refrigeration system 112 is also referred to herein as the “refrigerant.” The refrigerant is returned to the refrigeration circuit by a refrigerant return line 114, which routes the refrigerant toward a low-pressure line 120 of the compressor 102. As used herein, the "low-pressure line" of a compressor (e.g., compressor 102) refers to a refrigerant flow path within the compressor or the main refrigeration circuit of which compressor 102 is a part that precedes and routes refrigerant toward one or more impellers in a compression stage of the compressor (e.g., the first-stage impeller of the compressor). The low-pressure line 120 of the compressor 102 may include, for example, but is not limited to, a passage extending between the first-stage inlet of the compressor 102 and the first-stage impeller, the first-stage inlet of the compressor 102, and the suction line 110 connected to the first-stage inlet of the compressor 102 (e.g., the suction line 110).

[0017] The refrigerant used in the refrigeration system 112 is suitably drawn from the low-temperature, high-pressure side of the main refrigeration circuit downstream of the condenser 104 and upstream of the expansion device 106 (i.e., from a refrigerant line 122 connected between the condenser 104 and the expansion device 106), or alternatively, from the condenser 104. Drawing refrigerant from the main refrigeration circuit at this stage provides several advantages. The pressure differential across the refrigeration circuit 204 of the refrigeration system 112, i.e., between the high-pressure refrigerant exiting the condenser 104 and the low-pressure refrigerant entering the compressor 102 via the suction line 110, facilitates driving the refrigerant back through the compressor 102 and into the refrigeration circuit. The relatively low temperature of the refrigerant exiting the condenser 104 compared to the temperature of the refrigerant in downstream stages of the main refrigeration circuit (e.g., exiting the evaporator 108 and / or the expansion device 106), facilitates increasing the cooling capacity of the refrigeration system 112.

[0018] Using refrigerant from the high-pressure side of the main refrigeration circuit as a coolant can disrupt the flow of low-pressure refrigerant in the main refrigeration circuit entering the compressor 102 via the suction line 110. Conventionally, refrigerant enters the low-pressure line 120 of the compressor 202 through a single outlet connecting the refrigerant return line 114 and the low-pressure line 120. The refrigerant is drawn into the low-pressure line 120 by a pressure differential between the refrigerant return line 114 and the low-pressure line 120 and / or by suction between the refrigerant return line 114 and the low-pressure line 120 from the low-pressure refrigerant flowing through the low-pressure line 120. The refrigerant entering the low-pressure line 120 through the single outlet intersects with the low-pressure refrigerant flowing through the low-pressure line 120 at a single angular flow direction. The refrigerant intersecting with the low-pressure refrigerant at a single angular flow direction disrupts the flow of low-pressure refrigerant entering the compressor 102 and, therefore, the flow of refrigerant through the compressor 102. The performance, efficiency, and lifespan of the compressor 102 can be substantially reduced by turbulence in the flow of refrigerant through the compressor 102. For example, turbulence in the flow of refrigerant can adversely affect the direction of refrigerant flow contacting the impeller of the compressor 102. While the direction of refrigerant flow can be controlled using inlet guide vanes located upstream of the impeller within the compressor 102, the turbulence caused by the refrigerant intersecting the low-pressure refrigerant at a single angular flow direction can substantially reduce the effectiveness of the guide vanes, especially when the refrigerant enters the compressor 102 downstream of the inlet guide vanes.

[0019] 1 , the cooling system 112 includes a damping chamber 118 that distributes the flow of coolant entering the low-pressure line 120, where the coolant intersects with the low-pressure refrigerant in the low-pressure line 120 in multiple (i.e., two or more) flow directions (also referred to herein as “angular flow directions”) spaced at angular intervals about the central axis of the low-pressure line 120. The damping chamber 118 is located between the coolant return line 114 and the low-pressure line 120 (e.g., between the coolant return line 114 and the suction line 110). The damping chamber 118 has a damping chamber inlet connected to the coolant return line 114, through which the coolant enters the volume of the damping chamber 118. The damping chamber 118 also has one or more damping chamber outlets, suitably multiple (i.e., two or more) damping chamber outlets, through which the coolant enters the low-pressure line 120. The coolant enters the volume of the damping chamber 118 via the damping chamber inlet and accumulates within the damping chamber volume. The refrigerant in the damp chamber volume is driven through a damp chamber outlet into low-pressure line 120 by a pressure differential between the refrigerant and low-pressure refrigerant entering compressor 102 via suction line 110 and / or by suction between the damp chamber volume and low-pressure line 120 from low-pressure refrigerant flowing through low-pressure line 120. The damp chamber outlet is configured (e.g., sized, shaped, and positioned) such that refrigerant is driven through the damp chamber outlet and into low-pressure line 120 in a plurality of discrete angular flow directions. This reduces or eliminates turbulence to the flow of refrigerant through low-pressure line 120 caused by crossing refrigerant, thereby facilitating improved performance, efficiency, and lifespan of compressor 102.

[0020] 2 is a schematic diagram of an exemplary compressor system 200 suitable for use in the refrigeration system 100 of FIG. 1. The compressor system 200 includes a compressor 202 (e.g., compressor 102) and a cooling circuit 204. The cooling circuit 204 delivers coolant to components of the compressor 202 to facilitate cooling the compressor 202 and maintaining the components of the compressor 202 within a suitable operating temperature range. The cooling circuit 204 includes a damping chamber 205 (e.g., damping chamber 118) for distributing the flow of coolant entering a low-pressure line of the compressor 202 (e.g., compressor inlet 210, or passage P extending between the compressor 202 inlet 210 and the compressor 202 impeller 226).

[0021] 2 is a two-stage centrifugal compressor 202 including a first stage 206 and a second stage 208. Alternatively, the compressor 202 may be a single-stage centrifugal compressor (i.e., including a single stage 206 or 208), or the compressor 202 may include three or more stages. The compressor 202 may be a compressor other than a centrifugal compressor. The first stage 206 includes a first-stage inlet 210 connected in fluid communication with an evaporator (e.g., the evaporator 108 shown in FIG. 1) by a suction line 212 (e.g., the suction line 110 shown in FIG. 1). Low-pressure refrigerant exiting the evaporator 108 enters the first stage 206 of the compressor 202 via the first-stage inlet 210. The second stage 208 includes a second stage inlet 214 connected in fluid communication with the first stage outlet of the first stage 206 by a refrigerant transfer conduit (not shown in FIG. 2 ) for receiving compressed refrigerant from the first stage 206.

[0022] Compressor 202 includes a housing 216 and a shaft 218 rotatably supported in housing 216. Shaft 218 may be supported in housing 216 by bearings 220, 222, and 224. Alternatively, shaft 218 may be supported without the use of bearings 220, 222, and / or 224. Compressor 202 also includes a first stage impeller 226 connected to a first end 228 of shaft 218, a second stage impeller 230 connected to a second end 232 of shaft 218, and a motor 234 operably connected to shaft 218 to drive its rotation. Compressor 202 may include components in addition to those shown in FIG. 2 .

[0023] Housing 216 encloses the components of compressor 202 within one or more hermetic (e.g., hermetic or semi-hermetic) cavities. In some embodiments, for example, housing 216 includes end caps for each stage of compressor 202 that define volutes in which first stage impeller 226 and second stage impeller 230 are disposed. In some embodiments, housing 216 is formed from cast parts that are assembled using appropriate fasteners (e.g., screws, bolts, etc.).

[0024] Bearings 220, 222, and 224 may rotatably support shaft 218 in housing 216. In the example shown in FIG. 2 , compressor 202 includes first radial bearing 220, second radial bearing 222, and thrust bearing 224. In other embodiments, compressor 202 may include additional or fewer bearings. Bearings 220, 222, and 224 may include any suitable type of bearing that enables compressor 202 to function as described herein, including, but not limited to, roller-type bearings, magnetic bearings, fluid film bearings, air foil bearings, and combinations thereof. In one example, bearings 220, 222, and 224 each include an air foil-type bearing.

[0025] Motor 234 is operably connected to shaft 218 to drive the rotation thereof during operation of compressor 202. Motor 234 may include any suitable motor that enables compressor 202 to function as described herein. In the illustrated embodiment, motor 234 is an electric motor and includes suitable components (e.g., a stator and a rotor) for imparting rotational motion to shaft 218 during operation of compressor 202.

[0026] The housing 216 has coolant passages 236, 238, 240, 242 defined therein that route coolant toward the bearings 220, 222, 224 and the motor 234. The coolant passages 236, 238, 240, 242 may be arranged and / or defined within the compressor housing 216 in any manner that enables the compressor system 200 to function as described herein. For example, the coolant passages 236, 238, 240, 242 may be formed as passages within components of the compressor housing 216 (e.g., cast components, such as by machining), as passages defined between two or more components of the compressor 202 (e.g., between the motor 234 and the compressor housing 216), and combinations thereof.

[0027] The exemplary compressor 202 includes a first coolant flow path 236, a second coolant flow path 238, a third coolant flow path 240, and a fourth coolant flow path 242. The first coolant flow path 236 delivers coolant to the thrust bearing 224, the second coolant flow path 238 delivers coolant to the first radial bearing 220, the third coolant flow path 240 delivers coolant to the second radial bearing 222, and the fourth coolant flow path 242 delivers coolant to the motor 234. In some embodiments, the coolant flow paths 236, 238, 240, 242 may share common or overlapping portions. For example, as shown in FIG. 2, the first coolant flow passage 236 overlaps with and flows into the second coolant flow passage 238 in the first radial bearing 220, and the third coolant flow passage 240 overlaps with and flows into the fourth coolant flow passage 242 in the motor 234.

[0028] Each of the coolant flow paths 236, 238, 240, 242 has a corresponding coolant inlet port 244 that connects to the cooling circuit 204 in the exemplary embodiment. That is, the compressor housing 216 includes four external inlet connections for connecting the coolant flow paths 236, 238, 240, 242 with the coolant supply lines 248, 250, 252, 254, respectively. The compressor housing 216 may alternatively have fewer external inlet connections. For example, two or more of the coolant flow paths 236, 238, 240, 242 may share a common single coolant inlet port (and a common connection point to one or more coolant supply lines) that provides coolant to multiple of the coolant flow paths 236, 238, 240, 242. In such examples, the flow of coolant delivered to the common coolant inlet port may be separated, split, or otherwise directed within the compressor housing 216 to deliver coolant to two or more of the coolant flow paths 236, 238, 240, 242. In some embodiments, for example, the bearing coolant flow paths (i.e., the first coolant flow path 236, the second coolant flow path 238, and the third coolant flow path 240) may have a common coolant inlet port, and the flow of coolant may be directed to separate flow paths within the compressor housing 216.

[0029] The compressor housing 216 also defines a common coolant outlet port 246. The common coolant outlet port 246 receives coolant from each of the coolant flow paths 236, 238, 240, and 242. In other words, all coolant channeled through the coolant flow paths 236, 238, 240, and 242 toward the compressor housing 216 is returned to the common coolant outlet port 246. In some embodiments, at least one of the coolant flow paths 236, 238, and 240 is arranged such that coolant flows serially through the at least one coolant flow path, across at least one of the bearings 220, 222, and 224, and through the motor 234 to the common coolant outlet port 246. In this manner, the coolant flowing through the at least one coolant flow path absorbs heat from both the motor 234 and one of the bearings 220, 222, and 224. The coolant may flow through the motor 234, for example, by flowing between the stator and rotor of the motor 234, through a portion of the shaft 218 around which the motor 234 is disposed, and / or through passages or holes defined in the rotor of the motor 234.

[0030] The cooling circuit 204 delivers coolant toward the compressor housing 216 and the coolant flow paths 236, 238, 240, and 242 via coolant supply lines 248, 250, 252, and 254. The coolant supply lines 248, 250, 252, and 254 are connected in fluid communication with a coolant source 262 and are connected to the compressor housing 216 via an inlet 244 to deliver coolant to the coolant flow paths 236, 238, 240, and 242. The coolant supply lines 248, 250, 252, and 254 may include any suitable fluid conduits (rigid and / or flexible) that facilitate delivering coolant to the compressor housing 216, including, for example, but not limited to, pipes, hoses, tubing, and combinations thereof. In some embodiments, the coolant supply lines 248, 250, 252, and 254 are constructed of metal tubing, such as copper tubing. The example cooling circuit 204 includes four coolant supply lines 248, 250, 252, 254, one for each of the coolant flow paths 236, 238, 240, 242 defined within the compressor housing 216. More specifically, the example cooling circuit 204 includes bearing coolant supply lines 248, 250, 252 and a motor coolant supply line 254. Each of the bearing coolant supply lines 248, 250, 252 is connected to one of the first coolant flow path 236, the second coolant flow path 238, and the third coolant flow path 240 to route or deliver coolant to at least one of the compressor bearings 220, 222, 224. The motor coolant supply line 254 is connected to the fourth coolant flow path 242 to deliver coolant to the motor 234.

[0031] The exemplary refrigerant source 262 is suitably part of the main refrigeration circuit of which the compressor 202 is a part (e.g., the main refrigeration circuit of the refrigeration system 100 shown in FIG. 1 ). As described above, the refrigerant may be drawn from the refrigeration circuit at or downstream of the condenser of the refrigeration circuit (e.g., the condenser 104 shown in FIG. 1 ), such as between the condenser and the expansion device (e.g., the expansion device 106 shown in FIG. 1 ). The refrigerant is the same working fluid (e.g., refrigerant) used in the refrigeration system of this example. The refrigerant source 262 may be part of the refrigeration system other than downstream of the condenser. For example, the refrigerant source 262 may be the condenser itself. The refrigerant source 262 may be any other suitable refrigerant source that enables the compressor system 200 to function as described herein. For example, the refrigerant source 262 may be an auxiliary liquid cycle.

[0032] Suitably, the coolant drawn from the coolant source 262 is driven through the cooling circuit 204 using a pressure differential between the coolant source 262 and a low-pressure line upstream of the first stage impeller 226 of the compressor 202 (e.g., first stage inlet 210, or a passage P extending between the first stage inlet 210 and the first stage impeller 226). The coolant may be driven by the pressure differential without the need for auxiliary equipment (e.g., a pump). In other examples, the coolant may be directed through the cooling circuit 204 using auxiliary equipment (e.g., a pump).

[0033] At least one of the coolant supply lines 248, 250, 252, 254 may include a coolant control valve 264 for controlling the flow of coolant through the corresponding coolant supply line. The control valve 264 may include an electrically actuable valve controllable by the controller 260 to vary or otherwise control the flow rate of coolant through the corresponding supply line. Suitable valves include, for example, but are not limited to, solenoid valves, electronic expansion valves, and adjustable control valves. For example, the motor coolant supply line 254 includes the coolant control valve 264. Additionally and / or alternatively, one or more of the bearing coolant supply lines 248, 250, 252 may include the coolant control valve 264. For example, the motor coolant supply line 254 and one or more of the bearing coolant supply lines 248, 250, 252 may include the coolant control valve 264.

[0034] 2 , motor coolant supply line 254 is configured as a primary or main coolant supply line having an inlet 266 connected to coolant source 262 and an outlet 268 connected to compressor housing 216 to deliver coolant to fourth coolant flow path 242. Bearing coolant supply lines 248, 250, 252 are configured as branch lines, each having an inlet 270 connected to motor coolant supply line 254 upstream of coolant control valve 264 and an outlet 272 connected to compressor housing 216 to deliver coolant to first coolant flow path 236, second coolant flow path 238, and third coolant flow path 240. In other examples, one or more inlets 270 of bearing coolant supply lines 248, 250, 252 may be connected to coolant source 262. The motor coolant supply line 254 may also be configured as a branch circuit branching off from any of the bearing coolant supply lines 248 , 250 , 252 .

[0035] The cooling circuit 204 also includes a main shutoff valve 274 on the main coolant supply line (i.e., motor coolant supply line 254) that allows the flow of coolant to the entire cooling circuit 204 to be shut off in order to isolate the compressor 202 (e.g., for maintenance of the compressor 202). Alternatively, the main shutoff valve 274 may be omitted.

[0036] The bearing coolant supply lines 248, 250, 252 may not include individual shut-off valves or other devices that individually shut off the supply of coolant through the bearing coolant supply lines 248, 250, 252, as shown in FIG. 2 . Thus, while the cooling circuit 204 is active (e.g., the main shut-off valve 274 is open), the bearing coolant supply lines 248, 250, 252 are configured to continuously supply coolant to the compressor housing 216 regardless of the position of the coolant control valve 264. In this manner, the bearings of the compressor 202 are continuously supplied with coolant during operation, facilitating maintaining the bearings within a suitable operating temperature range. The bearing coolant flow paths, including the bearing coolant supply lines 248, 250, 252 and the associated coolant flow paths 236, 238, 240 defined within the compressor housing 216, may include flow restrictors (not shown) along the flow paths to restrict or otherwise limit the flow of coolant therethrough. The flow restrictors may be included in the bearing coolant supply lines 248, 250, 252 and / or may be incorporated into the compressor housing 216 (e.g., as metering orifices along the coolant flow paths). In some embodiments, for example, one or more of the coolant inlet ports 244 associated with the bearing coolant flow paths 236, 238, 240 include metering orifices for controlling the flow of coolant therethrough.

[0037] The refrigeration circuit 204 also returns refrigerant from the refrigerant flow paths 236, 238, 240, 242 to the main refrigeration circuit of which the compressor 202 is a part (e.g., the main refrigeration circuit of the refrigeration system 100 shown in FIG. 1). As shown in FIG. 2, the refrigeration circuit 204 includes a refrigerant return line 256 connected to the compressor housing 216 for receiving refrigerant from the refrigerant flow paths 236, 238, 240, 242 and routing the refrigerant toward the low-pressure line of the compressor 202. The low-pressure line of the compressor 202 refers to the refrigerant flow path within the compressor 202 or the main refrigeration circuit of which the compressor 202 is a part that precedes and routes refrigerant toward the impellers of the compressor 202 (i.e., the first-stage impeller 226 and the second-stage impeller 228). In the exemplary compressor system 200, the low-pressure line includes a passage P extending between the first-stage inlet 210 and the first-stage impeller 226. In other examples, the low pressure line of compressor 202 may include, for example, but not limited to, passage P, first stage inlet 210, or suction line 212 connected to first stage inlet 210.

[0038] The coolant return line 256 may include any suitable fluid conduit (rigid and / or flexible) that facilitates routing coolant between the coolant flow paths 236, 238, 240, 242 toward the lower pressure side of the compressor 202. Suitable conduits include, for example, without limitation, pipes, hoses, tubing, and combinations thereof. For example, the coolant return line 256 may be a conduit constructed of metal tubing, such as copper tubing, or the coolant return line 256 may be a conduit constructed of other materials.

[0039] 2 , the coolant return line 256 extends between the housing 216 and the low-pressure line of the compressor 202 external to the housing 216. In other words, the coolant return line 256 is shown as an additional conduit separate from and connected to the housing 216. In some examples, the coolant return line 256 is defined by the housing 216 and extends within the housing 216 between the coolant flow paths 236, 238, 240, 242 and the low-pressure line of the compressor 202. For example, the coolant return line 256 may be formed as a passage within a component of the compressor housing 216 (e.g., a cast component, such as by machining), as a passage defined between two or more components of the compressor 202 (e.g., between the motor 234 and the compressor housing 216), or as a combination thereof. The coolant return line 256 may be fully or semi-sealed using, for example, a hollow pin and an O-ring.

[0040] An inlet 276 of the coolant return line 256 is connected to the common coolant outlet port 246, and an outlet 278 of the coolant return line 256 is connected to an inlet 284 of the damping chamber 205. The coolant return line 256 receives coolant from each of the coolant passages 236, 238, 240, 242 via the inlet 276 after the coolant has absorbed heat from the motor 234 and / or the bearings 220, 222, 224. As described above, at least one of the coolant passages 236, 238, 240, 242 may be arranged such that coolant flows serially through the at least one coolant passage, across at least one of the bearings 220, 222, 224, through the motor 234, and to the common coolant outlet port 246. 2, the third cooling flow path 240 is arranged so that coolant flows serially across the second radial bearing 222, through the motor 234, and to a common coolant outlet port 246. As a result, even when the coolant control valve 264 is in the off position, the coolant flowing through the coolant return line 256 is absorbing heat from at least one of the bearings 220, 222, 224, and the motor 234.

[0041] The cooling circuit 204 may include a temperature sensor 258 connected to the coolant return line 256 to detect at least one of the temperature of the coolant in the coolant return line 256 and the temperature of the coolant in the coolant return line 256. The temperature sensor 258 may include any suitable temperature sensor that enables the cooling circuit 204 to function as described herein, including, for example, but not limited to, a thermistor (e.g., a negative temperature coefficient thermistor), a thermocouple, a resistance temperature detector (RTD), a thermal switch, and combinations thereof.

[0042] 2 is located entirely external to the compressor housing 216 and the refrigerant return line 256 and is configured to detect the temperature of the refrigerant return line 256. For example, the temperature sensor 258 may be connected to an outer surface of the refrigerant return line 256 and configured to detect the temperature of the outer surface. Additionally and / or alternatively, the temperature sensor 258 may include a probe extending into the refrigerant return line 256 to detect the temperature of the refrigerant flowing through the refrigerant return line 256. For example, if the refrigerant return line 256 is defined by and extends within the housing 216, the temperature sensor 258 may include a probe extending into the housing 216 and into the refrigerant return line 256.

[0043] Controller 260 is connected to temperature sensor 258 and coolant control valve 264 and is configured to control the operation of coolant control valve 264 (e.g., by opening, closing, or changing the position of coolant control valve 264). In some embodiments, for example, controller 260 is configured to control coolant control valve 264 to control the supply of coolant to compressor housing 216 based on the temperature detected by temperature sensor 258. For example, controller 260 may receive a signal from temperature sensor 258 indicative of the temperature detected by temperature sensor 258, compare the detected temperature to one or more temperature set points, and control coolant control valve 264 based on the detected temperature. More specifically, based on the comparison, controller 260 may be configured to open coolant control valve 264 to allow additional coolant flow through motor coolant supply line 254 to motor 234 or close coolant control valve 264 to reduce the flow of coolant through motor coolant supply line 254 to motor 234. "Opening" and "closing" the coolant control valve 264 may refer to absolute opening and closing (i.e., the valve being completely open or closed), or relative opening and closing of the valve (e.g., opening the valve more than it is already open, or closing the valve more than it is already closed).

[0044] Controller 260 generally includes any suitable computer and / or other processing unit, such as any suitable combination of computers, processing units, and / or the like, communicatively coupled to each other and capable of operating independently or in conjunction with each other (e.g., controller 260 can form all or part of a controller network). Controller 260 may include one or more modules or devices, one or more of which may be housed within compressor 202 or located remotely from compressor 202. Controller 260 may include one or more processor(s) 280 and associated memory device(s) 282 configured to perform various computer-implemented functions (e.g., perform the calculations, decisions, and functions disclosed herein). As used herein, the term “processor” refers not only to integrated circuits, but also to controllers, microcontrollers, microcomputers, programmable logic controllers (PLCs), application-specific integrated circuits, and other programmable circuits. Additionally, memory device(s) 282 of controller 260 may generally be or include memory element(s), including, but not limited to, computer-readable media (e.g., random access memory (RAM)), computer-readable non-volatile media (e.g., flash memory), floppy disks, compact disk read-only memories (CD-ROMs), magneto-optical disks (MODs), digital versatile disks (DVDs), and / or other suitable memory elements. Such memory device(s) 282 may generally be configured to store appropriate computer-readable instructions that, when implemented by a processor(s), configure or cause controller 260 to perform various functions described herein, including, but not limited to, controlling coolant control valve 264 and / or various other appropriate computer-implemented functions.

[0045] Controller 260 and / or components of controller 260 may be integrated or incorporated within other components of cooling circuit 204 and / or the refrigeration system in which cooling circuit 204 is incorporated. For example, controller 260 may be incorporated within a system controller that controls refrigerant control valve 264 and / or other functions and operations of compressor 202 and the refrigeration system.

[0046] The damping chamber 205 is located between the refrigerant return line 256 and a low-pressure line (e.g., path P) of the compressor 202. The damping chamber 205 includes a damping chamber inlet 284 connected to the refrigerant return line outlet 278. The damping chamber 205 receives refrigerant from the refrigerant return line 256 via the damping chamber inlet 284, which enters the interior volume V of the damping chamber 205. The damping chamber 205 also includes a damping chamber outlet 286 connected to the low-pressure line (e.g., path P) of the compressor 202. The refrigerant in the interior volume V of the damping chamber 205 exits the damping chamber 205 and enters the low-pressure line (e.g., path P) of the compressor 202 via the damping chamber outlet 286.

[0047] 2 , damping chamber 205 is defined by housing 216 and surrounds passage P extending between first stage inlet 210 and first stage impeller 226. Damping chamber 205 defined by housing 216 may additionally and / or alternatively surround first stage inlet 210. In some examples, damping chamber 205 may be separate from housing 216. For example, damping chamber 205 may be located adjacent to and surround suction line 212 such that coolant enters suction line 212 via damping chamber outlet 286 upstream of first stage inlet 210. Damping chamber 205 may be located in any suitable location that enables damping chamber 205 to function as described herein.

[0048] The damping chamber outlets 286 connect the damping chamber volume V to the passage P and are located at discrete angular locations circumferentially spaced about the passage P. The damping chamber outlets 286 facilitate distributing the flow of coolant entering the passage P such that the coolant intersects with the low pressure refrigerant in the passage P in multiple (i.e., two or more) angular flow directions. The damping chamber outlets 286 may include two or more outlets 286, such as three, four, five, six, or more than six outlets 286.

[0049] The damping chamber outlets 286 may each have the same shape and / or size, or the shapes and / or sizes of the damping chamber outlets 286 may be different. For example, the damping chamber outlets 286 may have the same cross-sectional size and / or shape, or the damping chamber outlets 286 may have different cross-sectional sizes and / or shapes. Additionally and / or alternatively, the damping chamber outlets 286 may have the same or different geometric shapes. The damping chamber outlets 286 may have any suitable geometric shape, such as, for example, a prism (e.g., cylindrical), a bell shape, a cone shape, a parabolic shape, and other shapes. Additionally and / or alternatively, the damping chamber outlets 286 may have the same and / or different orientations relative to the central axis of the passage P (and / or relative to the flow direction of the low-pressure refrigerant within the passage P). In some examples, as shown in FIG. 2 , the damping chamber outlets 286 may be oriented such that the refrigerant intersects the low-pressure refrigerant substantially perpendicularly in each angular flow direction. In other examples, some or all of the damping chamber outlets 286 may be oriented so that the coolant intersects the low pressure refrigerant at an oblique angle in some or all angular flow directions.

[0050] The damping chamber outlets 286 may be arranged in a staggered circumferential arrangement around the passage P, or the damping chamber outlets 286 may be aligned in a substantially circular circumferential arrangement around the passage P. The damping chamber outlets 286 may be arranged in any suitable configuration to enable the damping chamber 205 to function as described herein. The damping chamber outlets 286 may be located in substantial axial alignment with the damping chamber inlets 284, or the damping chamber outlets 286 may be axially offset from the damping chamber inlets 284. For example, some or all of the damping chamber outlets 286 may be located axially closer to the first stage inlet 210 than the damping chamber inlets 284, and / or some or all of the damping chamber outlets 286 may be located axially closer to the first stage impeller 226 than the damping chamber inlets 284.

[0051] The damping chamber inlet 284 and the damping chamber outlet 286 may be radially spaced from one another and formed as through-holes in the components of the housing 216 that define the damping chamber volume V. Suitably, the damping chamber outlet 286 together define a cross-sectional area through which the coolant enters the passage P that is equal to or greater than the cross-sectional area defined by the damping chamber inlet 284 through which the coolant enters the damping chamber volume V. This may reduce or eliminate backpressure on the coolant building up in the damping chamber volume V and allow the coolant to be driven into the passage P as described herein.

[0052] Refrigerant enters volume V of damp chamber 205 via damp chamber inlet 284 and accumulates within damp chamber volume V. The refrigerant in damp chamber volume V is driven into passage P through damp chamber outlet 286 by the pressure differential between the refrigerant and the low-pressure refrigerant flowing through passage P and / or by suction at damp chamber outlet 286 from the low-pressure refrigerant flowing through passage P. Damping chamber inlet 284 and damping chamber outlet 286 are appropriately sized to reduce or eliminate backpressure on the refrigerant accumulating within damping chamber V, thereby allowing the refrigerant to be driven into passage P by the pressure differential and / or suction. The refrigerant entering passage P is distributed by damp chamber outlet 286 to intersect with the low-pressure refrigerant flowing through passage P at a plurality of discrete angular flow directions. This reduces or eliminates turbulence in the flow of refrigerant through passage P caused by the intersecting refrigerant, thereby promoting improved performance, efficiency, and lifespan of compressor 202.

[0053] FIG. 3 is a perspective view of an exemplary compressor 300 suitable for use in the refrigeration system 100 shown in FIG. 1 (e.g., as compressor 102) and the compressor system 200 shown in FIG. 2 (e.g., as compressor 202). FIG. 4 is a cross-sectional view of the compressor 300 taken along line 3-3 in FIG. 3. The exemplary compressor 300 is a two-stage centrifugal compressor. The compressor 300 may alternatively include a single stage or more than two stages. The compressor 300 may be a compressor other than a centrifugal compressor.

[0054] The compressor 300 includes a compressor housing 302 that forms at least one sealed cavity within which stages of refrigerant compression are achieved. The compressor 300 includes a first refrigerant inlet 304 defined by the housing 302. The first refrigerant inlet 304 receives a working fluid (e.g., low-pressure refrigerant vapor) from a suction line 306 (e.g., suction line 110 shown in FIG. 1 and suction line 212 shown in FIG. 2). The refrigerant vapor enters the housing 302 through the first refrigerant inlet 304 and is routed through a path P toward a first compression stage 308. The refrigerant vapor is compressed within the first compression stage 308 and routed toward a first refrigerant outlet 310. The compressor 300 also includes a refrigerant transfer conduit 312 for transferring the compressed refrigerant from the first compression stage 308 to a second compression stage 314. A refrigerant transfer conduit 312 is operatively connected at opposite ends to a first refrigerant outlet 310 and a second refrigerant inlet 316 defined by the housing 302. Compressed refrigerant is routed from the first compression stage 308 through the refrigerant transfer conduit 312 and enters the second compression stage 314 through the second refrigerant inlet 316. The refrigerant is compressed within the second compression stage 314 and routed towards the second refrigerant outlet 318. The second refrigerant outlet 318 delivers the compressed refrigerant from the second compression stage 314 to a cooling or refrigeration system (e.g., refrigeration system 100) in which the compressor 300 is incorporated.

[0055] The compressor housing 302 includes a first housing end or cap 320 that encloses the first compression stage 308 and a second housing end or cap 322 that encloses the second compression stage 314. The first compression stage 308 and the second compression stage 314 are disposed at opposite ends of the compressor 300. The first compression stage 308 and the second compression stage 314 may alternatively be located at the same end of the compressor 300. The first compression stage 308 includes a first impeller 324 configured to add kinetic energy to the refrigerant entering via the first refrigerant inlet 304. The kinetic energy imparted to the refrigerant by the first impeller 324 is converted to increased refrigerant pressure (i.e., compression) as the refrigerant velocity is slowed upon transfer to an enclosed cavity (e.g., a diffuser). The second compression stage 314 includes a second impeller 326 configured to impart kinetic energy to the refrigerant transferred from the first compression stage 308, which enters via a second refrigerant inlet 316. The kinetic energy imparted to the refrigerant by the second impeller 326 is converted to increased refrigerant pressure (i.e., compression) as the refrigerant velocity is slowed upon transfer to an enclosed cavity (e.g., a diffuser). The compressed refrigerant exits the second compression stage 314 via a second refrigerant outlet 318.

[0056] The first impeller 324 and the second impeller 326 are coupled to opposite ends of a drive shaft 328. The drive shaft 328 is operably coupled to a motor 330 disposed within the housing 302 between the first impeller 324 and the second impeller 326. The motor 330 operates to rotate the drive shaft 328 such that the first impeller 324 and the second impeller 326 rotate at a selected rotational speed to compress the refrigerant exiting the second refrigerant outlet 318 to a preselected target (e.g., mass flow rate). Any suitable motor, including, but not limited to, an electric motor, may be incorporated into the compressor 300. The exemplary compressor 300 includes an electric motor having a stator 332 connected to the compressor housing 302 and a rotor 334 connected to the drive shaft 328. An air gap (not labeled in FIG. 4 ) is defined between the stator 332 and the rotor 334 to allow refrigerant to flow therethrough. Drive shaft 328 is supported by first and second radial foil bearings 336, 338, and thrust foil bearing 340. Additional details of compressor 300, including additional components and operation of compressor 300, are described in U.S. Pat. No. 11,391,291, issued July 19, 2022, the disclosure of which is incorporated herein by reference in its entirety.

[0057] 4 , compressor housing 302 includes coolant flow paths 342, 344, 346, and 348 defined therein that route coolant within housing 302 to provide cooling to bearings 336, 338, 340 and motor 330. The exemplary compressor 300 includes a first coolant flow path 342, a second coolant flow path 344, a third coolant flow path 346, and a fourth coolant flow path 348. First coolant flow path 342 routes coolant toward thrust bearing 340, second coolant flow path 344 routes coolant toward first radial bearing 336, third coolant flow path 346 delivers coolant to second radial bearing 338, and fourth coolant flow path 348 delivers coolant to motor 330. Compressor housing 302 also defines a common coolant outlet port 350 that receives coolant from each of coolant flow paths 342 , 344 , 346 , and 348 .

[0058] A first coolant passage 342 extends radially inward through the housing 302 near the first housing end cap 320, passes around the thrust bearing 340, and extends along the axial direction of the drive shaft 328 toward a common coolant outlet port 350. A second coolant passage 344 extends radially inward through the housing 302 toward the first radial bearing 336 and extends along the axial direction of the first radial bearing 336 and the drive shaft 328 toward the common coolant outlet port 350. A third coolant passage 346 extends radially inward through the housing 302 toward the second radial bearing 338 and extends along the axial direction of the second radial bearing 338 and the drive shaft 328 toward the common coolant outlet port 350. The fourth coolant flow passage 348 extends spirally around the stator 332 through a helical groove (not shown in FIG. 4 ) defined by the compressor housing 302. The fourth coolant flow passage 348 then extends radially inward to an air gap defined between the stator 332 and the rotor 334 and axially through the air gap toward a common coolant outlet port 350.

[0059] 4, the coolant flow paths 342, 344, 346, and 348 may share common or overlapping portions of the compressor housing 302. For example, the first coolant flow path 342 overlaps with and flows into the second coolant flow path 344 at the first radial bearing 336. The third coolant flow path 346 overlaps with and flows into the fourth coolant flow path 348 at the motor 330. Furthermore, as shown in FIG. 4 and described above, the coolant flow paths 342, 344, 346, and 348 in the example compressor housing 302 are arranged such that coolant flows serially through at least one of the coolant flow paths 342, 344, 346, and 348, across at least one of the bearings 336, 338, and 340, through the motor 330, and to a common coolant outlet port 350. For example, the third coolant flow path 346 delivers coolant to the second radial bearing 338 and the motor 330 (e.g., by flowing across the stator 332 and the rotor 334), so that the coolant absorbs heat from the bearings 336, 338, 340 and the motor 330.

[0060] A coolant return line 354 (schematically shown by a dotted line in FIGS. 3 and 4 ) has an inlet 352 connected to the common coolant outlet port 350 and an outlet 356 connected to an inlet 360 of a damping chamber 358 (described further below) for returning coolant to the low-pressure lines of the compressor 300 (e.g., the suction line 306, the first refrigerant inlet 304, and / or passage P). The coolant return line 354 may extend outside of the housing 302 between the inlet 352 and the outlet 356; i.e., the coolant return line 354 may be an additional conduit separate from and connected to the housing 302. Additionally and / or alternatively, the coolant return line 354 may be defined by the housing 302 and extend within the housing 302 between the inlet 352 and the outlet 356. For example, the coolant return line 354 may be formed as a passage within a component of the compressor housing 302 (e.g., a cast component, such as by machining), as a passage defined between two or more components of the compressor housing 302 (e.g., between the motor 330 and the compressor housing 302), and combinations thereof. The coolant return line 354 may be fully or semi-sealed using, for example, hollow pins and O-rings.

[0061] The low-pressure refrigerant vapor flowing through the low-pressure lines of compressor 300 (e.g., suction line 306, first refrigerant inlet 304, and / or passage P) is at a lower pressure than the refrigerant delivered to compressor housing 302. Suitably, the refrigerant is supplied from a relatively higher-pressure side of the refrigeration system in which compressor 300 is incorporated (e.g., refrigeration system 100 shown in FIG. 1), for example, at or downstream of a condenser (e.g., condenser 104, or refrigerant line 122 connected between condenser 104 and expansion device 106 shown in FIG. 1). As a result, a pressure differential exists between the refrigerant at the refrigerant source and the low-pressure lines of compressor 300. The pressure differential facilitates driving the refrigerant through refrigerant flow paths 342, 344, 346, 348 and refrigerant return line 354 toward the low-pressure lines of compressor 300.

[0062] The damping chamber 358 is located between the refrigerant return line 354 and a low-pressure line of the compressor 300 (e.g., the suction line 306, the first refrigerant inlet 304, and / or passage P). The damping chamber 358 includes a damping chamber inlet 360 connected to the refrigerant return line outlet 356. The damping chamber 358 receives refrigerant from the refrigerant return line 354 via the damping chamber inlet 360, which enters the interior volume V of the damping chamber 358. The damping chamber 358 also includes a damping chamber outlet 362 connected to the low-pressure line. In the exemplary compressor 300, the damping chamber outlet 362 is connected to passage P. The refrigerant in the interior volume V of the damping chamber 358 exits the damping chamber 358 and enters passage P via the damping chamber outlet 362.

[0063] In the exemplary compressor 300, as shown in FIG. 4, the damping chamber 358 is defined by a first housing end cap 320. The first housing end cap 320 also defines a passage P extending adjacent to the damping chamber 358 between the first refrigerant inlet 304 and the first impeller 324. The first housing end cap 320 includes an annular outer flange 364 for connecting the first refrigerant inlet 304 to the suction line 306. The first housing end cap 320 also includes an annular inner flange 366 and an inner tube 368 and an outer tube 370, each extending between the outer flange 364 and the inner flange 366. The outer tube 370 is spaced radially outward from the inner tube 368. The outer flange 364 and the inner flange 366 and the inner tube 368 and the outer tube 370 together define the damping chamber 358 and define an internal volume V. In the example compressor 300, the inner tube 368 and the outer tube 370 are concentric cylinders and define the cylindrical shape of the damping chamber 358. As described herein, the inner tube 368 and the outer tube 370 are not limited to being cylindrical. The inner tube 368 and the outer tube 370 may have any other shape that enables the damping chamber 358 to function as described herein. For example, the inner tube 368 and the outer tube 370 may be formed as hollow elongated structures having any suitable cross-sectional shape (e.g., circular, oval, rectangular, or other polygonal). In the example compressor 300, the inner tube 368 and the outer tube 370 are radially coextensive between the outer flange 364 and the inner flange 366. In other examples, the inner tube 368 and the outer tube 370 may have different radial lengths between the outer flange 364 and the inner flange 366.

[0064] The inner tube 368 surrounds and at least partially defines the passage P and includes a damping chamber outlet 362 formed therein. The damping chamber outlet 362 is connected to the passage P such that coolant exiting the damping chamber 358 via the outlet 362 enters the passage P. The damping chamber outlets 362 are located at discrete angular positions circumferentially spaced along the inner tube 368. The damping chamber outlets 362 facilitate distributing the flow of coolant entering the passage P such that the coolant intersects with the low-pressure refrigerant in the passage P in multiple (i.e., two or more) angular flow directions. The damping chamber outlets 362 may include two or more outlets 362, such as three, four, five, six, or more than six outlets 362. For example, the damping chamber outlets 362 may be formed as an annular or semi-annular array of through-holes extending circumferentially along the inner tube 368. As shown in FIG. 3 , where outer tube 370 and outer flange 364 are omitted to show interior volume V in more detail, damping chamber outlets 362 may be formed in a staggered circumferential array along inner tube 368. In other examples, damping chamber outlets 362 may be aligned in a substantially circular circumferential array along inner tube 368. Damping chamber outlets 362 may be formed in any suitable configuration to enable damping chamber 358 to function as described herein.

[0065] The damping chamber outlets 362 may each have the same shape and / or size, or the shapes and / or sizes of the damping chamber outlets 362 may be different. For example, the damping chamber outlets 362 may have the same cross-sectional size and / or shape, or the damping chamber outlets 362 may have different cross-sectional sizes and / or shapes. Additionally and / or alternatively, the damping chamber outlets 362 may have the same or different geometric shapes. The damping chamber outlets 362 may have any suitable geometric shape, such as, for example, a prism (e.g., cylindrical), a bell shape, a cone shape, a parabolic shape, and other shapes. Additionally and / or alternatively, the damping chamber outlets 362 may have the same and / or different orientations relative to the central axis of the passage P (and / or relative to the flow direction of the low-pressure refrigerant in the passage P). In some examples, as shown in FIG. 4 , the damping chamber outlets 362 may be oriented such that the refrigerant intersects the low-pressure refrigerant substantially perpendicularly in each angular flow direction. In other examples, some or all of the damping chamber outlets 362 may be oriented so that the coolant intersects the low pressure refrigerant at an oblique angle in some or all angular flow directions.

[0066] The outer tube 370 surrounds the internal volume V and the inner tube 368 and includes a damping chamber inlet 360 formed therein. In the exemplary compressor 300, the damping chamber 358 includes a single damping chamber inlet 360. Alternatively, the damping chamber inlet 360 may include two or more inlets 360. The damping chamber inlet 360 may be formed as a through-hole in the outer tube 370. The damping chamber inlet 360 may be formed in any suitable location to facilitate connection with the outlet 356 of the coolant return line 354. In the illustrated example, the damping chamber inlet 360 is formed in the outer tube 370 to facilitate connection with the coolant return line 354, which extends at least partially outside the housing 302. In other examples in which the coolant return line 354 is defined by and extends within the housing 302, the damping chamber inlet 360 may be formed in another suitable location to facilitate connection with the outlet of the coolant return line 354. For example, the damping chamber inlet 360 may be formed in the inner flange 366 .

[0067] Suitably, the damping chamber outlet 362 together define a cross-sectional area through which the coolant enters the passage P that is equal to or greater than the cross-sectional area defined by the damping chamber inlet 360 through which the coolant enters the damping chamber volume V. This may reduce or eliminate backpressure on the coolant building up in the damping chamber volume V and allow the coolant to be driven into the passage P as described herein.

[0068] The damping chamber outlets 362 may be located substantially axially aligned with the damping chamber inlets 360, or the damping chamber outlets 362 may be axially offset from the damping chamber inlets 360. For example, as shown in FIG. 4 , some or all of the damping chamber outlets 362 may be located axially closer to the first refrigerant inlet 304 than the damping chamber inlets 360. Additionally and / or alternatively, some or all of the damping chamber outlets 362 may be located axially closer to the first impeller 324 than the damping chamber inlets 360.

[0069] Refrigerant enters volume V of damp chamber 358 via damp chamber inlet 360 and accumulates within damp chamber volume V. The refrigerant in damp chamber volume V is driven into passage P through damp chamber outlet 362 by the pressure differential between the refrigerant and the low-pressure refrigerant flowing through passage P and / or by suction at damp chamber outlet 362 from the low-pressure refrigerant flowing through passage P. Damping chamber inlet 360 and damp chamber outlet 362 are appropriately sized to reduce or eliminate backpressure on the refrigerant accumulating within damp chamber V, thereby allowing the refrigerant to be driven into passage P by the pressure differential and / or suction. The refrigerant entering passage P is distributed by damp chamber outlet 362 to intersect with the low-pressure refrigerant flowing through passage P at a plurality of discrete angular flow directions. This reduces or eliminates turbulence in the flow of refrigerant through passage P caused by the intersecting refrigerant, thereby promoting improved performance, efficiency, and lifespan of compressor 300.

[0070] As shown in FIG. 4 , the compressor 300 may include a variable inlet guide vane 372 disposed in passage P between the first refrigerant inlet 304 and the first impeller 324. The position of the guide vane 372 may be controlled to direct the flow of refrigerant through passage P so that the refrigerant contacts the first impeller 324 in the appropriate direction. The damping chamber 358 in the example shown in FIG. 4 is positioned such that the damping chamber outlet 362 is upstream of the guide vane 372. Thus, the refrigerant entering passage P through the damping chamber outlet 362 mixes with the low-pressure refrigerant vapor in passage P upstream of the guide vane 372. By suitably positioning the damping chamber outlet 362 upstream of the guide vane 372, the guide vane 372 can direct the flow of the refrigerant after it mixes with the low-pressure refrigerant vapor in passage P.

[0071] 5 and 6, another exemplary compressor 400 is shown. FIG. 5 is a cross-sectional view of compressor 400 taken along a cross-sectional line similar to line 3-3 shown in FIG. 3. FIG. 6 is a cross-sectional view of section C of compressor 400 shown in FIG. 5. 400 5 and 6 are enlarged views of the portion indicated by "." Compressor 400 has a configuration similar to compressor 300 shown in Figures 3 and 4. Like compressor 300, compressor 400 is suitable for use in refrigeration system 100 shown in Figure 1 (e.g., as compressor 102) and compressor system 200 shown in Figure 2 (e.g., as compressor 202). Reference numbers in Figures 5 and 6 corresponding to those in Figures 3 and 4 are used to indicate corresponding parts between compressor 400 and compressor 300.

[0072] The compressor 400 includes a damping chamber 404 defined by a first housing end cap 402. The first housing end cap 402 is included in the compressor housing 302 and connected to its body 374. The damping chamber also defines the first refrigerant inlet 304 of the compressor 400. The damping chamber 404 surrounds a passage P extending between the inlet 304 and the first impeller 324. In this example, the damping chamber 404 is defined axially downstream from the inlet 304. Additionally, the first housing end cap 402 defines a portion of an inlet guide vane apparatus 500 (shown in FIG. 7 ) installed in the compressor 400. The inlet guide vane apparatus 500 will be described in more detail below and may also be referred to as an inlet guide 500. Additional details of the inlet guide 500, such as additional components and operation of the inlet guide 500, are described in U.S. patent application Ser. No. 18 / 186,273, filed March 20, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0073] First housing end cap 402 includes an annular flange 406 that defines the radially outermost portion of end cap 402. Annular flange 406 is connected to main housing body 374 of compressor housing 302. Annular flange 406 includes holes 407 formed therein that align with corresponding holes 376 formed in main housing body 374. The aligned end cap holes 407 and corresponding body holes 376 receive fasteners 378 to connect first housing end cap 402 with main housing body 374.

[0074] An annular flange 406 extends radially outward from an annular sidewall 408 of the first housing end cap 402. The annular sidewall 408 extends axially from a shoulder 410 of the end cap 402. The end cap 402 is open at the end of the annular sidewall 408 opposite the shoulder 410. A concave surface 416 facing the main housing body 374 is defined by the shoulder 410 and extends radially between the annular sidewall 408 and an inner wall 422. A damping chamber volume V is defined by the inner surface 414 of the annular sidewall 408, the concave surface 416, and the outer surface 426 of the inner wall 422. The shoulder 410 also defines an outer surface 418 opposite the concave surface 416. The end cap 402 also includes a neck portion 420 extending axially from the shoulder 410. The neck portion 420 has a smaller outer diameter than the annular sidewall 408. A shoulder 410 extends radially between the neck portion 420 and the annular sidewall 408 and joins the neck portion 420 and the annular sidewall 408.

[0075] End cap 402 includes an inner wall 422 extending axially outward from concave surface 416. Inner wall 422 is radially spaced from annular sidewall 408 and defines a damping chamber volume V. Inner wall 422 also forms a portion of inlet guide 500 defined by and integrally made with end cap 402. In particular, inner wall 422 forms a second housing portion of inlet guide 500 integrally made with end cap 402. Inner wall 422 may be integrally made with end cap 402 by manufacturing techniques including, but not limited to, casting, molding, powdered metal manufacturing, additive manufacturing or 3D printing, and machining (e.g., computer numerical control machining (CNC)). End cap 402 and inner wall 422 may be made from any suitable material, including, for example, cast iron, aluminum, steel, and alloys thereof, as well as plastic, and any combination of these materials. End cap 402 and inner wall 422 may also be made from graphite or another suitable self-lubricating material, which may be added, for example, during casting or molding. By making end cap 402 and inner wall 422 from a self-lubricating material, bearings within inlet guide 500 (shown in FIG. 7 ) may be unnecessary to facilitate rotation of ring gear 504 relative to inner wall 422 and / or housing portion 502.

[0076] The end cap 402 also includes a central bore 430 defined by a neck portion 420 and an inner wall 422. The central bore 430 extends axially through the cap 402 and defines the boundary of the first refrigerant inlet 304 and passage P of the compressor 400. The inner wall 422 surrounds a portion of passage P. As shown in FIG. 6, the central bore 430 is generally conical in shape, with the diameter defined by the central bore 430 decreasing in a direction from the refrigerant inlet 304 toward the first impeller 324 (shown in FIG. 5). The central bore 430 may alternatively be generally cylindrical in shape and define a generally constant diameter.

[0077] The inlet guide 500 is mounted proximate the refrigerant inlet 304 of the compressor 400. Low-pressure refrigerant vapor is channeled toward the inlet guide 500 through a passage P and exits the inlet guide 500 in the appropriate flow direction. The refrigerant is then channeled toward the first compression stage 308 (shown in FIG. 5 ), where the refrigerant contacts the first impeller 324 of the compressor 400 in the appropriate direction. Alternatively and / or additionally, the inlet guide vanes 500 are mounted proximate the inlet of each stage of the multi-stage compressor (e.g., the first refrigerant inlet 304 and the second refrigerant inlet 316).

[0078] Additional features and elements of inlet guide 500 are described with reference to FIG. 7 , which shows an exploded view of inlet guide 500. Inlet guide 500 includes end cap 402 and housing portion 502. When inlet guide 500 is assembled, inner wall 422 is connected to housing portion 502. End cap 402, and therefore inner wall 422, is positioned axially upstream of housing portion 502 when inlet guide 500 is installed in compressor 400. Inner wall 422 and housing portion 502 directly connect to form a guide vane housing assembly. Thus, housing portion 502 is directly connected to end cap 402. Housing portion 502 and inner wall 422 may be connected in any suitable manner that enables inlet guide 500 to function as described herein. For example, housing portion 502 may be connected to inner wall 422 by screws or other suitable fasteners.

[0079] In addition to the housing portion 502 and the inner wall 422, the inlet guide 500 includes a ring gear 504 and guide vanes 506. The ring gear 504 may be rotatably connected to the housing portion 502 and / or the inner wall 422 and rotatably supported within the inlet guide 500 by bearings 508. Each guide vane 506 is rotatable relative to a vane housing assembly of the inlet guide 500 and operatively connected to the ring gear 504 such that rotation of the ring gear 504 rotates each of the guide vanes 506 in unison. Each of the guide vanes 506 is rotatable relative to the vane housing assembly of the inlet guide 500 such that the orientation of the guide vane 506 within the passage P defined by the housing portion 502 and the inner wall 422 is selectively adjustable. In some embodiments, the guide vanes 506 are rotatable synchronously relative to the vane housing assembly of the inlet guide 500. Inlet guide 500 may also include one or more motors 510 operably connected to one or more of guide vanes 506 for selectively rotating guide vanes 506 .

[0080] Housing portion 502 includes an annular wall 512 having a first inner surface 514 and a first outer surface 516. Inner wall 422 has a second inner surface 424 and a second outer surface 426. First inner surface 514 and second inner surface 424 define a boundary of a passage P extending through the vane housing assembly. Housing portion 502 defines an outlet 518 of inlet guide 500. Refrigerant channeled through passage P enters the vane housing assembly of inlet guide 500, contacts guide vanes 506, exits the vane housing assembly via outlet 518, and is channeled toward first impeller 324 (shown in FIG. 5). Refrigerant exiting the vane housing assembly via outlet 518 has the proper flow direction imparted by guide vanes 506.

[0081] The vane housing assembly of inlet guide 500 surrounds first outer surface 516 and second outer surface 426 and includes an outer region 520 located radially outward from the vane housing assembly. At least a portion of each of guide vanes 506 is disposed between housing portion 502 and inner wall 422, and at least a portion of guide vanes 506 and ring gear 504 are disposed in outer region 520. Thus, ring gear 504 and at least a portion of guide vanes 506 are accessible (e.g., by an operator or technician) for inspection and / or repair without having to disassemble inlet guide 500. For example, an operator or technician may access portions of ring gear 504 and guide vanes 506 without first detaching housing portion 502 from end cap 402. Annular sidewall 408 may include a notch 432 formed therein. Notches 432 discontinuously extend through sidewall 408 and provide clearance to allow access to portions of ring gear 504 and guide vanes 506 without disassembling the vane housing assembly. Notches 432 may additionally and / or alternatively provide clearance for connecting one or more motors 510 to one or more of guide vanes 506.

[0082] Inner wall 422 includes a downstream surface 428 that is generally annular in shape. Inner wall 422 may have a width extending between second outer surface 426 and second inner surface 424 that is similar to the width of annular wall 512 of housing portion 502 extending between first inner surface 514 and first outer surface 516. The axial length of a portion of passage P extending through the vane housing assembly is defined by the axial lengths of inner wall 422 and annular wall 512. The diameter of passage P extending through the vane housing assembly is defined by the diameters of second inner surface 424 and first inner surface 514. The dimensions of the vane housing assembly, e.g., diameter and length, may be scaled to the size of compressor 400 and the aerodynamic needs of compressor 400 to define the appropriate dimensions of passage P extending through the vane housing assembly.

[0083] The downstream surface 428 of the inner wall 422 includes second channels 434 arranged in a radially symmetric pattern about the downstream surface 428. The upstream surface 522 of the housing portion 502 includes first channels 524 arranged in a radially symmetric pattern about the upstream surface 522. The upstream surface 522 includes the same number of first channels 524 as the number of second channels 434 included in the downstream surface 428. Each of the first channels 524 and second channels 434 may be identical and have the same size and shape. In the exemplary inlet guide 500, the first channels 524 and second channels 434 are shaped like segments of a cylinder. When the inlet guide 500 is assembled, each of the first channels 524 is aligned with one of the second channels 434 to cooperatively form a guide vane channel extending radially through the vane housing assembly. The guide vane channel thus formed is sized and shaped to receive at least a portion of the guide vane 506 therein.

[0084] The guide vanes 506 are received by guide vane channels formed by aligning the first channels 524 and the second channels 434 and are arranged in a radially symmetric pattern that mirrors the radially symmetric pattern of the first channels 524 and the second channels 434. The number of guide vanes 506 corresponds to the number of first channels 524 and second channels 434. In the example inlet guide 500, there are ten guide vanes 506 corresponding to the ten first channels 524 and the ten second channels 434. The inlet guide 500 may include any suitable number of guide vanes 506 that enables the inlet guide 500 to function as described herein. For example, the inlet guide 500 may include six guide vanes 506, seven guide vanes 506, eight guide vanes 506, nine guide vanes 506, or more than ten guide vanes 506.

[0085] Each of the guide vanes 506 received by one of the guide vane channels is at least partially disposed in a portion of the passage P extending through the vane housing assembly. The guide vanes 506 have any shape or size that enables the inlet guide 500 to function as described herein. Additionally, the shape and size of the guide vanes 506 may be selected based on the intended use of the inlet guide 500. For example, the size, shape, and angle of the guide vanes 506 may be selected based on the type and configuration of the compressor 400, the operating conditions, and / or the fluid type used with the compressor 400. Each of the guide vanes 506 is rotatable relative to the vane housing assembly of the inlet guide 500 such that the orientation of each of the guide vanes 506 within the passage P is selectively adjustable.

[0086] Ring gear 504 is rotatably connected to housing portion 502 and / or inner wall 422 and is rotatable about a central axis A defined by inlet guide 500. Ring gear 504 includes gear teeth 526 sized and shaped to mesh with vane gear teeth 528 on each of guide vanes 506. Rotation of ring gear 504 is transmitted to vane gear teeth 528, causing rotation of guide vanes 506 within the guide vane channels of inlet guide 500.

[0087] Ring gear 504 further includes a feature 530 on a surface opposite gear teeth 526. Feature 530 engages bearing 508 and prevents bearing 508 from axially translating relative to ring gear 504.

[0088] The ring gear 504 and vane gear teeth 528 are disposed in the exterior region 520 of the inlet guide 500, allowing an operator to inspect and / or repair the ring gear 504 without disconnecting the housing portion 502 and the interior wall 422. At least one of the guide vanes 506 may be a drive guide vane 532 operably connected to a motor 510 that drives the rotation of the drive guide vane 532. The rotation of the drive guide vane 532 causes the ring gear 504 to rotate, which transmits the rotation to the rest of the guide vanes 506, also referred to as driven guide vanes. Thus, all of the guide vanes 506 rotate synchronously. The motor 510 may be a stepper motor. The motor may be communicatively connected to a controller (e.g., controller 260), which sends one or more commands to the motor, causing the motor to rotate the drive guide vane 506 to properly orient the guide vane 532 within the passage P. The simultaneous rotation of the guide vanes 506 changes the orientation of the guide vanes 506 relative to the flow of refrigerant through the vane housing assembly. The guide vanes 506 may be synchronously rotated to place the inlet guide 500 in any suitable position relative to the refrigerant flow, such as a fully open position or a neutral position, based on the operational needs of the compressor 400. For example, the position of the guide vanes 506 may be selected to increase the operating range of the compressor 400, including both surge and choke.

[0089] The inlet guide 500 may include a bearing 508 disposed between the housing portion 502 and the ring gear 504. The bearing 508 facilitates rotation of the ring gear 504 relative to the housing portion 502. The bearing 508 may be connected to the ring gear 504; for example, the bearing 508 is press-fit to frictionally engage with the mechanism 530. Thus, the ring gear 504 and the bearing 508 rotate relative to the housing portion 502. Alternatively, the bearing 508 may be press-fit onto the housing portion 502 such that the bearing 508 and the housing portion 502 frictionally engage and the ring gear 504 rotates relative to the bearing 508 and the housing portion 502. The bearing 508 may be a non-lubricated bearing or a self-lubricating bearing and may include any suitable type of bearing 508 that enables the inlet guide 500 to function as described herein. The bearing 508 may be omitted, and the ring gear 504 may rotate relative to the housing portion 502 without the use of a bearing. For example, housing portion 502 and / or inner wall 422 may be made from a self-lubricating material (eg, graphite), which may eliminate the need for bearings.

[0090] 5-7 , a damping chamber 404 defined by the first housing end cap 402 is located between the coolant return line 354 and the passage P of the compressor 400. In the exemplary compressor 400, the coolant return line 354 is formed as a passage within a component (e.g., a cast component, such as by machining) of the body 374 of the compressor housing 302. The coolant return line 354, formed as an internal passage within the component of the body 374, extends between a common coolant outlet port 350 and an outlet 356. The common coolant outlet port 350 may be formed adjacent to an air gap defined between the stator 332 and the rotor 334. The coolant return line 354 extends axially and internally from the common coolant outlet port 350 through the component of the body 374 to the outlet 356. The outlet 356 of the coolant return line 354 is formed as an exterior opening in the body 374, allowing coolant to enter a damping chamber volume V defined by the first housing end cap 402. The outlet 356 thereby also forms a damping chamber inlet 436 through which coolant flows into the damping chamber volume V. The damping chamber volume V is sealed by the annular flange 406, the annular sidewall 408, and the shoulder 410 of the end cap 402. The coolant return line 354 may be sealed or semi-sealed, for example, using a hollow pin and an O-ring.

[0091] Damping chamber 404 also includes a damping chamber outlet 438 connected to passage P. Refrigerant in damping chamber volume V exits damping chamber 404 and enters passage P of compressor 400 via damping chamber outlet 438. Damper chamber outlet 438 is formed in inner wall 422 axially upstream from second channel 434 formed in downstream face 428. Damping chamber outlet 438 is thus connected to passage P upstream of guide vane 506 such that refrigerant exiting damping chamber 404 via outlet 438 enters passage P and mixes with low-pressure refrigerant vapor upstream of guide vane 506.

[0092] The damping chamber outlets 438 are located at discrete angular positions circumferentially spaced along the inner wall 422. The damping chamber outlets 438 facilitate distributing the flow of coolant entering passage P such that the coolant intersects with the low-pressure refrigerant in passage P in multiple (i.e., two or more) angular flow directions. The damping chamber outlets 438 may include two or more outlets 438, such as three, four, five, six, or more than six outlets 438. For example, the damping chamber outlets 438 may be formed in the inner wall 422 as an annular or semi-annular array of through-holes extending circumferentially along the inner wall 422. In some examples, the damping chamber outlets 438 may be formed in a staggered circumferential array along the inner wall 422. In other examples, the damping chamber outlets 438 may be aligned in a substantially circular circumferential array along the inner wall 422. The damping chamber outlets 438 may be formed in any suitable configuration to enable the damping chamber 404 to function as described herein.

[0093] The damping chamber outlets 438 may each have the same shape and / or size, or the shapes and / or sizes of the damping chamber outlets 438 may be different. For example, the damping chamber outlets 438 may have the same cross-sectional size and / or shape, or the damping chamber outlets 438 may have different cross-sectional sizes and / or shapes. Additionally and / or alternatively, the damping chamber outlets 438 may have the same or different geometric shapes. The damping chamber outlets 438 may have any suitable geometric shape, such as, for example, a prism (e.g., cylindrical), a bell shape, a cone shape, a parabolic shape, and other shapes. Additionally and / or alternatively, the damping chamber outlets 438 may have the same and / or different orientations relative to the central axis of the passage P (and / or relative to the flow direction of the low-pressure refrigerant in the passage P). In some examples, as shown in FIG. 6 , the damping chamber outlets 438 may be oriented such that the refrigerant intersects the low-pressure refrigerant substantially perpendicularly in each angular flow direction. In other examples, some or all of the damping chamber outlets 438 may be oriented so that the coolant intersects the low-pressure refrigerant at an oblique angle in some or all angular flow directions. For example, some or all of the damping chamber outlets 438 may be oriented at an oblique angle toward the guide vanes 506, such that the coolant in some or all angular flow directions flows generally toward the guide vanes 506.

[0094] Suitably, the damping chamber outlet 438 together define a cross-sectional area through which the coolant enters the passage P that is equal to or greater than the cross-sectional area defined by the damping chamber inlet 436 through which the coolant enters the damping chamber volume V. This may reduce or eliminate backpressure on the coolant building up in the damping chamber volume V and allow the coolant to be driven into the passage P as described herein.

[0095] Refrigerant enters volume V of damp chamber 404 via damp chamber inlet 436 and accumulates within damp chamber volume V. The refrigerant in damp chamber volume V is driven into passage P through damp chamber outlet 438 by the pressure differential between the refrigerant and the low-pressure refrigerant flowing through passage P and / or by suction at damp chamber outlet 438 from the low-pressure refrigerant flowing through passage P. Damping chamber inlet 436 and damping chamber outlet 438 are appropriately sized to reduce or eliminate backpressure on the refrigerant accumulating within damping chamber V, thereby allowing the refrigerant to be driven into passage P by the pressure differential and / or suction. The refrigerant entering passage P is distributed by damp chamber outlet 438 to intersect with the low-pressure refrigerant flowing through passage P at a plurality of discrete angular flow directions. This reduces or eliminates turbulence in the flow of refrigerant through passage P caused by the intersecting refrigerant, thereby promoting improved performance, efficiency, and lifespan of compressor 400.

[0096] Exemplary embodiments of compressor systems and methods, such as refrigerant compressors, are described in detail above. The systems and methods are not limited to the specific embodiments described herein; rather, components of the systems and methods may be used independently and separately from other components described herein. For example, the refrigeration circuits described herein may be used with compressors other than centrifugal compressors, including, but not limited to, scroll compressors, rotary compressors, and reciprocating compressors.

[0097] As used herein, the terms "about," "substantially," "essentially," and "approximately," when used in conjunction with ranges of dimensions, concentrations, temperatures, or other physical or chemical properties or characteristics, are meant to encompass variations that may exist at the upper and / or lower limits of the range of that property or characteristic, including, for example, variations that result from rounding, measurement methodology, or other statistical variations.

[0098] When introducing elements of the present disclosure or embodiment(s) thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," "containing," and "having" are intended to be inclusive and mean that additional elements may be present other than the listed elements. The use of specific orientation terms (e.g., "top," "bottom," "side," etc.) is for convenience of description and does not require any particular orientation of the items being described.

[0099] Since various changes can be made in the above-described structures and methods without departing from the scope of the present disclosure, all matter contained in the above description and shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense.

Claims

1. 1. A refrigeration system comprising: Housing and a shaft rotatably supported within the housing; an impeller connected to the shaft; a motor operably connected to the shaft; a compressor comprising: an evaporator connected to a low-pressure line of the compressor; A condenser; an expansion device; Cooling circuit and The cooling circuit comprises: at least one refrigerant supply line for conveying refrigerant from one of the condenser and a refrigerant line connected between the condenser and the expansion device toward the housing; at least one coolant flow path defined by the housing that receives the coolant from the at least one coolant supply line and directs the coolant toward the motor; a refrigerant return line for conveying the refrigerant from the at least one refrigerant flow path toward the low pressure line of the compressor; a damping chamber located between the refrigerant return line and the low pressure line of the compressor; The damping chamber comprises: a damping chamber inlet connected to the coolant return line to allow the coolant to enter the damping chamber volume from the coolant return line; a damping chamber outlet connected to the low pressure line of the compressor to allow the refrigerant in the damping chamber volume to enter the low pressure line of the compressor; A refrigeration system comprising:

2. 2. The refrigeration system of claim 1, wherein the housing defines a passageway extending between a compressor inlet and the impeller, and the damping chamber outlet is connected to the passageway to allow the refrigerant within the damping chamber volume to enter the passageway.

3. The refrigeration system of claim 2 , wherein a guide vane is disposed within the passageway, and the damping chamber outlet is connected to the passageway upstream of the guide vane.

4. The refrigeration system of claim 1 , wherein the damping chamber outlet is configured to allow the refrigerant to enter the low pressure line of the compressor at discrete angular flow directions.

5. 2. The refrigeration system of claim 1, wherein the damping chamber outlet and the damping chamber inlet together define a cross-sectional area through which the refrigerant enters the low pressure line of the compressor that is equal to or greater than a cross-sectional area defined by the damping chamber inlet through which the refrigerant enters the damping chamber volume.

6. The refrigeration system of claim 1 , wherein the damping chamber is defined by an end cap of the housing.

7. 7. The refrigeration system of claim 6, wherein the damping chamber volume is defined between an inner tube and an outer tube of the end cap, the inner tube at least partially defining a passage extending between a compressor inlet and the impeller, the inner tube having the damping chamber outlet formed therein, the damping chamber outlet connected to the passage.

8. 8. The refrigeration system of claim 7, wherein the damping chamber inlet is formed in the outer pipe, and the coolant return line is connected between the at least one coolant flow path and the damping chamber inlet, and the coolant return line is external to the housing.

9. The refrigeration system of claim 8 , wherein the damping chamber outlet is axially offset from the damping chamber inlet.

10. The refrigeration system of claim 7 , wherein the coolant return line is defined by the housing and extends within the housing between the at least one coolant flow path and the damping chamber.

11. 1. A compressor system comprising: a housing defining a compressor inlet; a shaft rotatably supported within the housing; an impeller connected to the shaft, the impeller having a passage extending between the housing, the compressor inlet, and the impeller; a motor operably connected to the shaft; a compressor comprising: at least one coolant flow passage defined by the housing for receiving coolant and directing the coolant toward the motor; a coolant return line for conveying the coolant from the at least one coolant flow path toward the passage; a damping chamber located between the coolant return line and the passage; a cooling circuit comprising: The damping chamber comprises: a damping chamber inlet connected to the coolant return line to allow the coolant to enter the damping chamber volume from the coolant return line; a damping chamber outlet connected to the passage for allowing the coolant in the damping chamber volume to enter the passage at discrete angular flow directions; A compressor system comprising:

12. The compressor system of claim 11 , wherein the damping chamber comprises a single damping chamber inlet connected to the refrigerant return line.

13. 12. The compressor system of claim 11, wherein the damping chamber outlets together define a cross-sectional area through which the refrigerant enters the passageway that is equal to or greater than a cross-sectional area defined by the damping chamber inlet through which the refrigerant enters the damping chamber volume.

14. 12. The compressor system of claim 11, wherein the compressor inlet and the damping chamber are defined by an end cap of the housing, the damping chamber volume being defined between an inner tube and an outer tube of the end cap, the inner tube at least partially defining the passageway and having the damping chamber outlet formed therein.

15. 15. The compressor system of claim 14, wherein the damping chamber inlet is formed in the outer tube, and the coolant return line is connected between the at least one coolant flow path and the damping chamber inlet, and the coolant return line is external to the housing.

16. The compressor system of claim 15 , wherein the damping chamber outlet is axially offset from the damping chamber inlet.

17. The compressor system of claim 14 , wherein the coolant return line is defined by the housing and extends within the housing between the at least one coolant flow path and the damping chamber.

18. The compressor system of claim 11 , wherein a guide vane is disposed within the passageway, and the damping chamber outlet is connected to the passageway upstream of the guide vane.

19. A method of operating a refrigeration system including a compressor, an evaporator, a condenser, and an expansion device, the compressor including a housing, a shaft rotatably supported within the housing, an impeller connected to the shaft, and a motor operably connected to the shaft, the method comprising: compressing a refrigerant using the compressor to produce a compressed refrigerant; condensing the compressed refrigerant using the condenser to produce a compressed condensed refrigerant; expanding a first portion of the compressed condensed refrigerant using the expansion device to produce uncompressed condensed refrigerant; evaporating the uncompressed condensed refrigerant using the evaporator to produce uncompressed vapor refrigerant; directing the uncompressed vapor refrigerant toward a low pressure line of the compressor; diverting a second portion of the compressed condensed refrigerant toward the housing of the compressor to provide cooling to the motor; directing the second portion of the compressed condensed refrigerant toward the low pressure line of the compressor; mixing the second portion of the compressed condensed refrigerant with the uncompressed vapor refrigerant in the low pressure line of the compressor, wherein mixing the second portion of the compressed condensed refrigerant with the uncompressed vapor refrigerant in the low pressure line of the compressor includes intersecting the uncompressed vapor refrigerant with the second portion of the compressed condensed refrigerant in the low pressure line at a discrete angular flow direction; A method comprising:

20. 20. The method of claim 19, wherein the housing of the compressor defines at least one refrigerant flow path for receiving the second portion of the compressed condensed refrigerant and a damping chamber located between the at least one refrigerant flow path and the low-pressure line of the compressor, and wherein intersecting the second portion of the compressed condensed refrigerant with the uncompressed vapor refrigerant in the low-pressure line at the discrete angular flow directions comprises injecting the second portion of the compressed condensed refrigerant into the low-pressure line at the discrete angular flow directions through an outlet of the damping chamber.

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