Systems and methods for lubricant management in hvacr systems

Abstract

A lubricant management system for an HVACR system is disclosed. A lubricant management system includes a compressor, first and second sets of orifices, and a flow regulating valve. The compressor includes a lubricant inlet port and a lubricant outlet port. The first set of orifices is adapted to receive lubricant via a first passage and a second passage (via a flow regulating valve disposed in the second passage) such that the first passage and the second passage are fluidly connected. The second set of orifices is adapted to receive lubricant supplied by the first passage and the second passage. Further, the second set of orifices is adapted to supply the received lubricant to each of the lubricant inlet ports such that the flow regulating valve opens to supply lubricant based on a pressure difference between the first pressure region and the second pressure region of the compressor.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 555,308, filed on February 19, 2024, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates to lubrication systems for compressors of heating, ventilation, air conditioning, and refrigeration (HVACR) systems. More particularly, the present disclosure relates to a lubricant management system for optimizing the supply of lubricant to the compressors of HVACR systems. Background Art

[0004] HVACR systems typically include a compressor, which may be a screw compressor or a scroll compressor, etc. Such compressors use bearings to facilitate the rotation of the shaft. The bearings are generally equipped with a lubrication system to facilitate smooth rotation of the shaft.

[0005] Conventionally, compressors include a lubrication system that supplies lubricant to the compression chamber and / or bearings of the compressor. Thus, existing lubrication systems provide lubrication, cooling, and improved sealing within the compression chamber. However, the flow of lubricant to the compressor's bearings is driven by the pressure differential between the discharge and suction pressures of the HVACR system. In this regard, compressors are required to operate under both extremely low and extremely high differential pressure conditions. In the event of insufficient lubrication during extremely low or extremely high differential pressure conditions, the bearings, and therefore the compressor, may experience premature failure before reaching the expected bearing life.

[0006] Therefore, it is desirable to provide a lubrication management system and method that optimizes the supply of lubricant to an HVACR system compressor. Summary of the Invention

[0007] This summary is provided to introduce a selection of concepts in a simplified form that are further described in the detailed description of the invention. This summary is not intended to identify key or essential inventive concepts of the invention, nor is it intended to be used to determine the scope of the invention.

[0008] A lubricant management system for a heating, ventilation, air conditioning, and refrigeration (HVACR) system is disclosed. The lubricant management system includes a compressor, a first group of orifices, a second group of orifices, and a flow regulating valve. The compressor includes a plurality of lubricant inlet ports and a plurality of lubricant outlet ports. The first group of orifices includes: a first orifice adapted to receive lubricant via a first passage; and a second orifice adapted to receive lubricant via a flow regulating valve disposed in a second passage, such that the first passage and the second passage are fluidly connected. The second group of orifices is adapted to receive lubricant supplied by the first passage and the second passage. In addition, the second group of orifices is adapted to supply the received lubricant to each of the lubricant inlet ports, such that the flow regulating valve is adapted to open to supply lubricant based on a pressure differential between a first pressure zone and a second pressure zone of the HVACR system.

[0009] In one or more embodiments according to the present disclosure, an opening of the second aperture is larger than an opening of the first aperture.

[0010] In one or more embodiments according to the present disclosure, the first pressure zone is a zone upstream of the first set of orifices and the flow regulating valve.

[0011] In one or more embodiments according to the present disclosure, the second pressure zone is a zone downstream of each of the second set of orifices.

[0012] In one or more embodiments according to the present disclosure, the flow regulating valve is adapted to open to supply lubricant based on a pressure difference between a first pressure zone and a second pressure zone of the compressor exceeding a first threshold pressure difference.

[0013] In one or more embodiments according to the present disclosure, the flow regulating valve is adapted to open to supply lubricant based on a pressure difference between the first pressure zone and the second pressure zone of the compressor falling below a second threshold pressure difference.

[0014] In one or more embodiments according to the present disclosure, the flow regulating valve is adapted to close based on a pressure differential range between the first pressure zone and the second pressure zone of the compressor being between the second threshold pressure differential and the first threshold pressure differential.

[0015] A method for optimizing lubricant supply to a compressor of a heating, ventilation, air conditioning, and refrigeration (HVACR) system is disclosed. The method includes providing a lubricant management system comprising a compressor, a first set of orifices, a second set of orifices, and a flow regulating valve. The method then includes selectively actuating the flow regulating valve to open and supply lubricant based on a pressure differential between a first pressure zone and a second pressure zone of the HVACR system.

[0016] In one or more embodiments according to the present disclosure, selectively actuating the flow regulating valve to open to supply lubricant includes determining whether a pressure difference between a first pressure zone and a second pressure zone of the compressor exceeds a first threshold pressure difference, and actuating the flow regulating valve to supply lubricant.

[0017] In one or more embodiments according to the present disclosure, selectively actuating the flow regulating valve to open to supply lubricant includes determining whether a pressure differential between a first pressure zone and a second pressure zone of the compressor drops below a second threshold pressure differential, and actuating the flow regulating valve to supply lubricant.

[0018] In one or more embodiments according to the present disclosure, the first pressure zone is a zone upstream of the first set of orifices and the flow regulating valve.

[0019] In one or more embodiments according to the present disclosure, the second pressure zone is a zone downstream of each of the second set of orifices.

[0020] In one or more embodiments according to the present disclosure, an opening of the second aperture is larger than an opening of the first aperture.

[0021] In one or more embodiments according to the present disclosure, the flow regulating valve is adapted to close based on a pressure differential range between the first pressure zone and the second pressure zone of the compressor being between the second threshold pressure differential and the first threshold pressure differential.

[0022] To further illustrate the advantages and features of the methods, systems, and devices / apparatuses, the methods, systems, and devices / apparatuses will be described in more detail with reference to specific embodiments thereof shown in the accompanying drawings. It will be appreciated that these figures depict only typical embodiments of the present disclosure and are not to be considered as limiting the scope thereof. The accompanying drawings will be used to describe and explain the present disclosure with additional specificity and detail. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] These and other features, aspects and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings, in which like characters represent like parts throughout the figures, and in which:

[0024] Figure 1 shows a schematic diagram depicting a refrigerant circuit of a heating, ventilation, air conditioning, and refrigeration (HVACR) system according to one or more embodiments of the present disclosure;

[0025] Figure 2A A block diagram illustrating a lubrication management system deployed in a compressor of a heating, ventilation, air conditioning, and refrigeration (HVACR) system according to one or more embodiments of the present disclosure;

[0026] Figure 2BA diagram illustrating a typical compressor operating envelope plotted between a first pressure zone and a second pressure zone of a heating, ventilation, air conditioning, and refrigeration (HVACR) system according to one or more embodiments of the present disclosure; and

[0027] Figure 3 A flow chart depicting a method for optimizing lubricant supply to a compressor of an HVACR system, according to one or more embodiments of the present disclosure, is shown.

[0028] Furthermore, the skilled artisan will recognize that the elements in the figures are illustrated for simplicity and may not necessarily be drawn to scale. For example, a flow chart illustrates the method in terms of the most prominent steps involved to help improve understanding of aspects of the present disclosure. Furthermore, depending on the configuration of the device, one or more components of the device may be represented in the figures by conventional symbols, and the figures may only show those specific details that are relevant to understanding the embodiments of the present disclosure so as not to obscure the figures with details that would be readily apparent to one of ordinary skill in the art having the benefit of the description herein. DETAILED DESCRIPTION

[0029] For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to various embodiments and specific language will be used to describe the same. It will be understood, however, that no limitation of the scope of the disclosure is intended thereby, and such alterations and further modifications in the illustrated systems and devices, and such further applications of the principles of the disclosure as illustrated therein, are contemplated as would normally occur to one skilled in the art to which the disclosure relates.

[0030] It will be understood by those skilled in the art that both the foregoing general description and the following detailed description are explanatory of the present disclosure and are not intended to be restrictive thereof.

[0031] Reference throughout this specification to "on one hand," "on the other hand," or similar language means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Thus, appearances of the phrases "in one embodiment," "in another embodiment," "some embodiments," "one or more embodiments," and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

[0032] The terms "comprises," "comprising," or any other variations thereof are intended to cover a non-exclusive inclusion such that a process or method that comprises a list of steps includes not only those steps but may also include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or subsystems or elements or structures or components preceded by "comprises ..." does not, without more constraints, exclude the presence of other devices or other subsystems or other elements or other structures or other components or additional devices or additional subsystems or additional elements or additional structures or additional components.

[0033] The term "unit" used herein may mean a unit including, for example, one of hardware, software, and firmware, or a combination of two or more thereof. "Unit" may be used interchangeably with terms such as logic, logic block, component, circuit, etc. A "unit" may be a minimum system component for performing one or more functions, or may be a part thereof.

[0034] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0035] Figure 1 A schematic diagram depicting an exemplary refrigerant circuit of a heating, ventilation, air conditioning and refrigeration (HVACR) system 100 according to one or more embodiments of the present disclosure is shown. As used herein, "heating, ventilation, air conditioning and refrigeration (HVACR) system 100" refers to a conventional freezer, air conditioner, refrigeration system or heat pump that employs a compressor, oil separator, condenser, metering device and vaporizer connected in that order. It will be appreciated that the HVACR system 100 may include several additional components to regulate flow, pressure and other parameters. Such additional components may include, but are not limited to, regulating valves, on / off valves, ejectors, and the like. The compressor 101 used in such an HVACR system 100 may include, but is not limited to, a reciprocating compressor, a rotary compressor, a scroll compressor, a screw compressor, a centrifugal compressor, and the like. The compressor 101 of the HVACR system 100 disclosed herein compresses the refrigerant vapor to increase the pressure and temperature of the refrigerant vapor, up to a superheat level. In addition to the oil, the compressor 101 Figure 1 The discharge line shown as an example is used to discharge the superheated refrigerant vapor.

[0036] As used herein, "oil" refers to the lubricating oil used to lubricate the moving components of compressor 101. The oil in compressor 101 also serves to cool the bearings and improve the smooth movement of the moving parts, thereby increasing system efficiency and extending the life of the bearings. Condenser 105 is adapted to receive a mixture of oil and refrigerant vapor discharged from the compressor. Condenser 105 may include an oil storage and separation section 107, which serves to separate the oil from the mixture of oil and refrigerant vapor discharged from compressor 101. In an embodiment, oil storage and separation section 107 may be housed within a secondary shell within a single shell. Alternatively, oil storage and separation section 107 and condenser section 106 may be enclosed within a single shell. Excess oil is collected in oil storage and separation section 107 and supplied back to compressor 101 via an oil return line. On the other hand, the separated refrigerant vapor rises and is transferred to condenser section 106.

[0037] The separated oil within the oil storage and separation section 107 of the condenser 105 is continuously supplied to the compressor 101 via an oil return line connected to the compressor 101. If the residual oil level is insufficient to supply the compressor 101, the oil level switch will detect the lack of oil, and the controller will trip the system and sound an alarm. The pressure differential between the high and low sides of the HVACR system 100 is the driving force for the oil to travel from the condenser 105 to the compressor 101. In certain embodiments, auxiliary components such as an oil pump and an intermediate oil reservoir may also be used to supply oil to the compressor 101.

[0038] The oil storage and separation section 107 is adapted to transfer the refrigerant vapor separated from the mixture of oil and refrigerant vapor from the oil storage and separation section 107 to the condenser section 106 of the condenser 105. The condenser section 106 condenses the separated refrigerant vapor into a high-temperature refrigerant fluid. The chilled water circuit 104 exchanges heat with the condenser section 106, thereby cooling the refrigerant vapor to form a high-temperature refrigerant fluid. The high-temperature refrigerant fluid then passes through a metering device 102 (such as an expansion valve) to expand the condensed refrigerant fluid. After passing through the metering device 102, the refrigerant fluid's pressure is further reduced, lowering its temperature, thereby supplying the low-temperature and low-pressure refrigerant fluid to the evaporator 103. The evaporator 103 vaporizes the refrigerant fluid. The chilled water circuit 104' exchanges heat with the refrigerant fluid in the evaporator 103. The chilled water circuit 104' can then circulate to an external terminal unit (e.g., a fan coil unit) to exchange heat with air from the space to be cooled. When the low-temperature and low-pressure refrigerant fluid passes through the evaporator 103, the chilled water circuit 104' to be cooled exchanges heat with the refrigerant fluid, thereby completely converting the refrigerant fluid into low-temperature and low-pressure refrigerant vapor. Finally, the low-pressure refrigerant vapor is supplied back to the compressor 101 to complete the refrigerant circuit.

[0039] Figure 2A A block diagram is shown of a lubricant management system 200 deployed in a compressor 101 of a heating, ventilation, air conditioning, and refrigeration (HVACR) system 100 , according to one or more embodiments of the present disclosure.

[0040] The lubricant management system 200 disclosed herein includes a compressor 101; a first set of orifices 201, 202; a flow control valve 203; and a second set of orifices 204a, 204b, 204c. The compressor 101 includes a plurality of lubricant inlet ports 207a, 207b, 207c and a plurality of lubricant outlet ports. The first set of orifices 201, 202 includes a first orifice 201 and a second orifice 202. The first orifice 201 is adapted to receive lubricant via a first passage 205. The second orifice 202 is adapted to receive lubricant via a flow control valve 203 disposed in a second passage 206. In an embodiment, the opening of the second orifice 202 is larger than the opening of the first orifice 201. The first passage 205 and the second passage 206 are fluidly connected to the compressor 101 at one end and to the condenser 105 or a lubricant reservoir (not shown) at the other end. The first passage 205 and the second passage 206 collectively supply lubricant to each of the lubricant inlet ports 207a, 207b, 207c via the second set of apertures 204a, 204b, 204c, respectively. It will be appreciated that the openings of the first set of apertures 201, 202 and the second set of apertures 204a, 204b, 204c may have a circular cross-sectional profile or any other cross-sectional shape profile, such as oval, rectangular, elliptical, square, etc., without departing from the scope of the present disclosure.

[0041] The second set of orifices 204a, 204b, 204c is adapted to receive lubricant supplied from the liquid reservoir or condenser 105 via the first and second passages 205, 206. Furthermore, the second set of orifices 204a, 204b, 204c is adapted to supply the received lubricant to each of the lubricant inlet ports 207a, 207b, 207c, respectively. The lubricant management system 200 optimizes lubricant flow, such that the flow regulating valve 203 is adapted to open to supply lubricant based on the pressure differential between the first and second pressure zones of the HVACR system 100. The first pressure zone is upstream of the first set of orifices 201, 202 and the flow regulating valve 203. In an embodiment, the flow regulating valve 203 is a solenoid valve. The second pressure zone is downstream of each of the second set of orifices 204a, 204b, 204c.

[0042] like Figure 2A, the first set of orifices 201, 202 is shown as including only the first orifice 201 and the second orifice 202. Furthermore, the second set of orifices is 204a, 204b, 204c, and only a single flow regulating valve 203 is depicted in the block diagram. However, it will be appreciated that several configurations are contemplated without departing from the scope of the present disclosure. For example, the number of first sets of orifices 201, 202 may include more than two orifices without departing from the scope of the present disclosure. Similarly, the second set of orifices 204a, 204b, 204c may include only two orifices or more than three orifices. Thus, it will be appreciated that the number of orifices, the number of associated passages, and the number of flow regulating valves may be selected based on the desired flow setting of the lubricant management system 100.

[0043] Flow control valve 203 is adapted to open to supply lubricant when the pressure differential between the first and second pressure zones of HVACR system 100 exceeds a first threshold pressure differential. Alternatively, flow control valve 203 is adapted to open to supply lubricant when the pressure differential between the first and second pressure zones of compressor 101 falls below a second threshold pressure differential. Under extremely low or high pressure differential conditions, flow control valve 203 opens, and the pressure drop across the first set of orifices 201, 202 decreases, resulting in an increase in the overall flow rate, thereby providing sufficient lubricant flow to the bearings. This is achieved by an oil manifold block with a built-in solenoid valve. The block has an inlet passage, which then divides into a first passage 205 through first orifice 201 and a second passage 206 through second orifice 202. Because second orifice 202 has a larger opening than first orifice 201, second passage 206 has a larger opening than first passage 205. The opening and closing of the larger second passage 206 is controlled by flow control valve 203 (a solenoid valve). Finally, the first passage 205 and the second passage 206 are connected together to supply the compressor 101 .

[0044] Flow regulating valve 203 is adapted to close based on the pressure differential between the first and second pressure zones of compressor 101 being between a second threshold pressure differential and the first threshold pressure differential. Under normal pressure differential conditions, flow regulating valve 203 is closed, and lubricant flows only through second orifice 202, resulting in a high pressure drop across the first set of orifices 201, 202 and, consequently, a low flow rate of lubricant to the bearings through the second set of orifices 204a, 204b, 204c. As a result, by providing sufficient lubricant flow for bearing lubrication, compressor 101 can operate under extremely low pressure differential conditions without lubrication failure. Compressor 101 can operate during normal conditions without sacrificing efficiency due to oversupply of oil. Furthermore, by providing sufficient lubricant for bearing cooling, compressor 101 can operate under extremely high pressure differentials without bearing failure due to overheating.

[0045] Figure 2B 1 shows a typical compressor operating envelope plotted between a first pressure zone and a second pressure zone of a heating, ventilation, air conditioning, and refrigeration (HVACR) system 100 according to one or more embodiments of the present disclosure. Figure 2A As disclosed in the detailed description of FIG, the flow regulating valve 203 is adapted to open to supply lubricant based on the pressure differential between the first pressure zone and the second pressure zone of the HVACR system 100 exceeding a first threshold pressure differential or falling below a second threshold pressure differential. Under extremely low pressure differential conditions or extremely high pressure differential conditions, the flow regulating valve 203 opens and the pressure drop across the first set of orifices 201, 202 decreases, resulting in an increase in the overall flow rate, thereby providing sufficient lubricant flow to the bearings.

[0046] As shown in the figure, the area between the dashed lines A and B is a normal pressure differential area (when the pressure differential range is between the second threshold pressure differential and the first threshold pressure differential). In this range, the flow regulating valve 203 is closed, and the lubricant flows only through the second orifice 202, resulting in a high pressure drop across the first set of orifices 201, 202 and therefore a low flow rate of lubricant to the bearing through the second set of orifices 204a, 204b, 204c.

[0047] As shown in the figure, the area above dashed line A is a high differential pressure region (when the pressure differential between the first and second pressure zones of the HVACR system 100 exceeds a first threshold pressure differential). Similarly, the area below dashed line B is a low differential pressure region (when the pressure differential between the first and second pressure zones of the HVACR system 100 drops below a second threshold pressure differential). Under extremely low or high differential pressure conditions, the flow control valve 203 opens, and the pressure drop across the first set of orifices 201, 202 decreases, resulting in an increase in the overall flow rate, thereby providing sufficient lubricant flow to the bearings. The lubricant management system 200 disclosed herein can vary the overall flow of lubricant to the compressor 101 without affecting the ratio of the total flow of lubricant to each inlet port of the compressor 101. Some components, such as bearings, require more lubricant than others, such as rotors. With this arrangement, the bearings will always receive more lubricant than the rotor, regardless of the overall flow rate. This makes lubricant usage and supply more efficient.

[0048] Figure 3 A flow chart depicting a method 300 for optimizing lubricant supply to a compressor 101 of a heating, ventilation, air conditioning, and refrigeration (HVACR) system 100 is shown.

[0049] At step 301 , the method 300 includes providing a lubricant management system 200 including: a compressor 101 ; a first set of orifices 201 , 202 ; a second set of orifices 204 a , 204 b , 204 c ; and a flow regulating valve 203 .

[0050] At step 303 , the method 300 includes selectively actuating the flow regulating valve 203 to open to supply lubricant based on a pressure differential between a first pressure zone and a second pressure zone of the HVACR system 100 .

[0051] In one or more embodiments, selectively actuating the flow regulating valve 203 to supply lubricant includes determining whether a pressure differential between the first and second pressure zones of the HVACR system 100 exceeds a first threshold pressure differential, and actuating the flow regulating valve 203 to supply lubricant.

[0052] In one or more embodiments, selectively actuating the flow regulating valve 203 to open to supply lubricant includes determining whether the pressure differential between the first and second pressure zones of the HVACR system 100 drops below a second threshold pressure differential, and actuating the flow regulating valve 203 to supply lubricant.

[0053] Although specific language is used to describe the subject matter, it is not intended that any limitation be created thereby. As will be apparent to those skilled in the art, various adaptability modifications may be made to the method to implement the inventive concept as taught herein. The figures and the foregoing description provide examples of embodiments. Those skilled in the art will recognize that one or more of the elements described may be well combined into a single functional element. Alternatively, certain elements may be divided into multiple functional elements. Elements from one embodiment may be added to another embodiment.

Claims

1. A lubricant management system for a heating, ventilation, air conditioning, and refrigeration (HVACR) system, the lubricant management system comprising: a compressor comprising a plurality of lubricant inlet ports and a plurality of lubricant outlet ports; A first set of orifices, said first set of orifices comprising: a first orifice adapted to receive lubricant via a first passage; a second orifice adapted to receive the lubricant via a flow regulating valve disposed in a second passage, wherein the first passage and the second passage are fluidly connected; a second set of orifices adapted to receive the lubricant supplied by the first and second passages, the second set of orifices adapted to supply the received lubricant to each of the lubricant inlet ports of the compressor, The flow regulating valve is adapted to open to supply the lubricant based on a pressure difference between a first pressure zone and a second pressure zone of the HVACR system.

2. The lubricant management system according to claim 1, wherein: An opening of the second orifice is larger than an opening of the first orifice.

3. The lubricant management system according to claim 1, wherein: The first pressure zone is a zone upstream of the first set of orifices and the flow regulating valve.

4. The lubricant management system of claim 1 , wherein: The second pressure zone is a zone downstream of each of the second set of orifices.

5. The lubricant management system of claim 1 , wherein: The flow regulating valve is adapted to open to supply the lubricant based on a pressure differential between a first pressure zone and a second pressure zone of the HVACR system exceeding a first threshold pressure differential.

6. The lubricant management system of claim 1, wherein: The flow regulating valve is adapted to open to supply the lubricant based on a pressure differential between a first pressure zone and a second pressure zone of the HVACR system falling below a second threshold pressure differential.

7. The lubricant management system of claim 1, wherein: The flow regulating valve is adapted to close based on a pressure differential between a first pressure zone and a second pressure zone of the HVACR system ranging between a second threshold pressure differential and a first threshold pressure differential.

8. A method for optimizing lubricant supply to a compressor of a heating, ventilation, air conditioning, and refrigeration (HVACR) system, the method comprising: providing a lubricant management system comprising a compressor, a first set of orifices, a second set of orifices, and a flow regulating valve; as well as The flow regulating valve is selectively actuated to open to supply lubricant based on a pressure differential between a first pressure zone and a second pressure zone of the HVACR system.

9. The method according to claim 8, wherein Selectively actuating the flow regulating valve to open to supply the lubricant includes: determining whether a pressure differential between a first pressure zone and a second pressure zone of the HVACR system exceeds a first threshold pressure differential; and The flow regulating valve is actuated to supply the lubricant.

10. The method according to claim 8, wherein Selectively actuating the flow regulating valve to open to supply the lubricant includes: determining whether a pressure differential between a first pressure zone and a second pressure zone of the HVACR system falls below a second threshold pressure differential; and The flow regulating valve is actuated to supply the lubricant.

11. The lubricant management system of claim 8, wherein: The first pressure zone is a zone upstream of the first set of orifices and the flow regulating valve.

12. The lubricant management system of claim 8, wherein: The second pressure zone is a zone downstream of each of the second set of orifices.

13. The lubricant management system of claim 8, wherein: The opening of the second orifice is larger than the opening of the first orifice.

14. The lubricant management system of claim 8, wherein: The flow regulating valve is adapted to close based on a pressure differential between a first pressure zone and a second pressure zone of the HVACR system ranging between a second threshold pressure differential and a first threshold pressure differential.

Images