KR20240067968A - Fluid flow control for a compressor lubrication system - Google Patents

Abstract

A fluid pressure control system 110 for compressor 32 includes a pump 90 configured to direct lubricant toward bearings 96 of compressor 32 and feedback indicating the speed of shaft 94 of compressor 32. The shaft 94 is configured to be supported at least partially by a bearing 96. The fluid pressure control system 110 also may, when executed by the processor 44, cause the processor 44 to receive signals indicative of the speed of the shaft 94 from the sensor 112 and to operate the pump 90 based on these signals. A non-transitory computer-readable medium having executable instructions configured to control operation.

Description

Fluid flow control for compressor lubrication system {FLUID FLOW CONTROL FOR A COMPRESSOR LUBRICATION SYSTEM}

Cross-reference to related applications

This application claims priority and the benefit of U.S. Provisional Application No. 62/834,871, filed April 16, 2019, entitled “FLUID PRESSURE CONTROL FOR A COMPRESSOR,” and incorporated herein by reference in its entirety for all purposes. do.

This section is intended to introduce the reader to various aspects of technology that may be related to the various aspects of the disclosure described below. This discussion is believed to be helpful in providing the reader with background information to better understand various aspects of the disclosure. Accordingly, this statement should be read in this light and with the understanding that it is not an admission of prior art.

Heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) systems are used for many purposes in a variety of environments. For example, an HVAC&R system may include a vapor compression refrigeration system (e.g., a refrigerant circuit with a condenser, evaporator, compressor, and/or expansion device) configured to condition the environment. A vapor compression refrigeration system may include a lubrication circuit that directs a lubricating fluid (e.g., oil) into the compressor to provide lubrication to various components (e.g., bearings) of the compressor. Conditions within the compressor, such as temperature and pressure, may change during compressor operation. Unfortunately, traditional HVAC&R systems may supply lubricating fluid to the compressor at a constant pressure, which can cause the lubricating fluid to flow to unintended locations within the HVAC&R system as conditions within the compressor change.

In an embodiment of the present disclosure, a fluid pressure control system for a compressor includes a pump configured to direct lubricant toward a bearing of the compressor, a sensor configured to provide feedback indicative of the speed of a shaft of the compressor, the shaft being at least partially It is configured to be supported by bearings. The fluid pressure control system may also include a non-transitory computer readout having executable instructions that, when executed by a processor, are configured to cause the processor to receive signals indicative of the speed of the shaft from the sensor and adjust the operation of the pump based on these signals. Includes possible media.

In an embodiment of the present disclosure, a fluid pressure control system for a compressor, when executed by a pump configured to direct lubricant toward a bearing of the compressor, a sensor configured to provide feedback indicative of the temperature within the compressor at the bearing, and a processor, comprises: and at least one non-transitory computer-readable medium having executable instructions, wherein the processor is configured to receive a signal from a sensor indicative of a temperature within the compressor at the bearing and adjust the speed of the pump based on the signal.

In an embodiment of the present disclosure, a fluid pressure control system for a compressor includes a pump configured to direct lubricant toward a bearing of the compressor, a first sensor configured to provide feedback indicative of the speed of the shaft of the compressor, and a first sensor configured to provide feedback indicative of the speed of the shaft of the compressor, and within the compressor at the bearing. and a second sensor configured to provide feedback indicative of temperature. The shaft is configured to be supported at least partially by bearings. The fluid pressure control system may also be configured to, when executed by a processor, cause the processor to receive a first signal from a first sensor indicative of the speed of the shaft, a second signal indicative of a temperature within the compressor at the bearings from a second sensor, and At least one non-transitory computer-readable medium having executable instructions configured to adjust the speed of the pump based on the first signal, the second signal, or both.

1 is a perspective view of a building that may utilize an embodiment of a heating, ventilation, air conditioning and/or refrigeration (HVAC&R) system in a commercial environment, in accordance with aspects of the present disclosure.
2 is a perspective view of an embodiment of an HVAC&R system, in accordance with aspects of the present disclosure.
3 is a schematic diagram of an embodiment of a vapor compression system, in accordance with aspects of the present disclosure.
4 is a schematic diagram of another embodiment of a vapor compression system, according to aspects of the present disclosure.
5 is a schematic diagram of an embodiment of a vapor compression system with a sump, in accordance with aspects of the present disclosure.
6 is a schematic diagram of an embodiment of a vapor compression system with a fluid pressure control system, according to aspects of the present disclosure.
FIG. 7 is a flow diagram illustrating an embodiment of a process for operating a fluid pressure control system of a vapor compression system, in accordance with aspects of the present disclosure.
8 is a flow diagram illustrating an embodiment of a process for operating a fluid pressure control system of a vapor compression system, in accordance with aspects of the present disclosure.
9 is a flow diagram illustrating an embodiment of a process for operating a fluid pressure control system of a vapor compression system, in accordance with aspects of the present disclosure.

One or more specific embodiments of the present disclosure will be described below. These embodiments described are merely examples of the technology disclosed herein. Additionally, in an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. As in any engineering or design scheme, in the development of any such practical implementation, many decisions are specific to the implementation to achieve the developer's particular objectives, such as compliance with system-related and business-related constraints that may vary from implementation to implementation. It must be understood that this can be achieved. Additionally, it should be understood that such a development effort may be complex and time consuming, but will nonetheless be a routine design, fabrication, and manufacturing task for those skilled in the art who would benefit from the present disclosure.

As previously mentioned, vapor compression systems typically include refrigerant flowing through a cooling circuit. The refrigerant flows through a number of conduits and components arranged along the cooling circuit while undergoing a phase change that allows the vapor compression system to condition the interior space of the structure. Vapor compression systems typically involve flowing a fluid (e.g., a refrigerant, such as oil) through certain components of the refrigeration circuit (e.g., compressor, sump, and cooler) to lubricate the compressor of the refrigeration circuit during operation. It includes a lubrication circuit having a. The compressor includes a shaft coupled to a rotor configured to compress refrigerant within the compressor. The shaft is supported by at least one bearing, and the fluid in the lubrication circuit is generally configured to lubricate the shaft as it rotates as it flows between the shaft and the bearing.

The pump in the lubrication circuit pumps fluid along the lubrication circuit from the sump to the compressor. Specifically, fluid flows from the sump to the bearings and to the shaft of the compressor. The pump may pump fluid along a lubrication circuit (eg, to a bearing) at a constant flow rate and/or pressure. During operation of the compressor, certain factors may be involved, such as the operating mode of the compressor in general and/or the operating conditions of the vapor compression system (e.g., the temperature and/or pressure of the refrigerant flowing through the refrigerant circuit, operator input, or Due to the combination of ), the shaft speed may vary. Additionally or alternatively, the temperature of the lubricating fluid in the compressor and in the bearings is generally determined by the operating mode of the compressor and/or the operating parameters of the vapor compression system (e.g., the temperature of the refrigerant flowing through the refrigerant circuit and/or or pressure, friction between the shaft and other components of the compressor (e.g., rotor), or combinations thereof).

The compressor includes seals (e.g., hermetic seals and/or labyrinth seals) configured to seal fluid that flows through and lubricates components of the compressor (e.g., bearings and/or shafts). . However, as the shaft speed and/or temperature at the bearing changes, fluid flowing at a constant flow rate and/or pressure may leak from the seal of the compressor. For example, when shaft speeds and/or temperatures are relatively low, the pressure of the fluid within the compressor may increase due to fluid flowing along the bearings and/or shaft at a constant flow rate, which may result in increased fluid pressure in the seal. may cause leakage. When shaft speeds and/or temperatures are relatively high, fluid may not flow at a sufficient rate to properly lubricate the bearings and/or shaft (e.g., the constant flow rate of fluid may be too small to properly lubricate the bearings and/or shafts). /or may not be able to properly lubricate the shaft). Improper lubrication of the bearings and/or shafts may cause overheating of the bearings, shafts, and/or compressors due to increased friction. Accordingly, a constant flow rate of fluid along the lubrication circuit, along with variable shaft speed and/or variable temperature of the fluid within the compressor, can reduce the efficiency of the compressor and vapor compression system.

Some examples of fluids that can be used as refrigerants in embodiments of the vapor compression system of the present disclosure include hydrofluorocarbon (HFC) based refrigerants, such as R-410A, R-407, R-134a, hydrofluoroolefins, (HFO) based refrigerants, such as R-1233 or R-1234, “natural” refrigerants, such as ammonia (NH ₃ ), R-717, carbon dioxide (CO ₂ ), R-744 or hydrocarbon based refrigerants, water vapor. , or any other suitable refrigerant. In some embodiments, the vapor compression system efficiently compresses a refrigerant with a normal boiling point of about 19 degrees Celsius (66 degrees Fahrenheit) at 1 atmosphere (also referred to as a low pressure refrigerant), as compared to a medium pressure refrigerant, such as R-134a. It can be configured to be utilized. As used herein, “normal boiling point” may refer to the boiling point temperature measured at 1 atmosphere. Examples of some fluids that can be used as lubricants in embodiments of vapor compression systems of the present disclosure are synthetic oil, mineral oil, or any other suitable lubricant.

This disclosure relates to a fluid pressure control system for a compressor in a vapor compression system. Certain embodiments of the fluid pressure control system include sensors that detect the temperature within the compressor at the shaft speed and/or bearings of the compressor. For example, a first sensor may be disposed on a shaft to provide feedback indicative of shaft speed and/or a second sensor may be disposed in a bearing to provide feedback indicative of the temperature within the compressor at the bearing. In certain embodiments, additional sensors may be disposed in the compressor's supply conduit and/or the compressor's drain conduit to provide feedback indicative of fluid supply temperature and fluid drain temperature, respectively. Based on the fluid supply temperature and/or fluid drain temperature, the controller of the fluid pressure control system can determine the temperature within the compressor at the bearings.

Based on the shaft speed and/or the temperature within the compressor at the bearing, the controller of the fluid pressure control system may adjust the flow rate of fluid from the pump to the bearing (e.g., may adjust the pressure of the fluid in the lubrication circuit). . The controller may determine the target flow rate based on shaft speed and/or temperature and may adjust the speed of the pump so that the flow rate of fluid reaches the target flow rate. The target flow rate may be a function of shaft speed and/or temperature within the compressor at the bearings (e.g., a linear function, a non-linear function, a proportional function, an exponential function, or a combination thereof). When the shaft speed and/or temperature is reduced overall, the controller may adjust the speed of the pump to reduce the flow rate of fluid to an overall lower target flow rate. When the shaft speed and/or temperature increases overall, the controller may adjust the speed of the pump to increase the flow rate of fluid to an overall higher target flow rate. As the controller adjusts the flow rate of the fluid, the overall operation and/or efficiency of the compressor and vapor compression system may be improved. For example, adjustments to the flow rate of the fluid can at least partially block or reduce leakage of fluid from seals of the compressor and/or reduce friction between the fluid, shaft, and/or bearings.

The control techniques of this disclosure can be used in a variety of systems. However, for ease of explanation, examples of systems that may include the control techniques of the present disclosure are shown in Figures 1-4 and are described below.

Referring now to Figure 1, Figure 1 is a perspective view of an embodiment of an environment for a heating, ventilation, and air conditioning (HVAC) system within a building 12 for a typical commercial environment. The HVAC system 10 may include a vapor compression system 14 that supplies chilled liquid that can be used for cooling the building 12. HVAC system 10 may also include a boiler 16 to supply warm liquid to heat building 12, and an air distribution system to circulate air through building 12. The air distribution system may also include an air return conduit 18, an air supply conduit 20, and/or an air handler 22. In some embodiments, air handler 22 may include a heat exchanger connected to boiler 16 and vapor compression system 14 by conduit 24. The heat exchanger within air handler 22 may receive heated liquid from boiler 16 or cooled liquid from vapor compression system 14, depending on the mode of operation of HVAC system 10. The HVAC system 10 is shown with a separate air handler on each floor of the building 12, but in other embodiments, the HVAC system 10 includes an air handler 22 and an air handler 22 that may be shared between floors. /or may include other components.

2 and 3 show an embodiment of a vapor compression system 14 that may be used within HVAC system 10. Vapor compression system 14 may circulate refrigerant through a circuit beginning with compressor 32. The circuit may also include a condenser 34, expansion valve(s) or device(s) 36, and a liquid cooler or evaporator 38. The vapor compression system 14 includes a control panel 40 having an analog/digital (A/D) converter 42, a microprocessor 44, a non-volatile memory 46, and/or an interface board 48. ) (eg, a controller) may be further included.

In some embodiments, vapor compression system 14 includes a variable speed drive (VSD) 52, motor 50, compressor 32, condenser 34, expansion valve or device 36, and/or evaporator ( 38), one or more of these can be used. The motor 50 may drive the compressor 32 and may be supplied with power by a variable speed drive (VSD) 52. VSD 52 accepts alternating current (AC) power from an AC power source with a specific fixed line voltage and fixed line frequency, and provides power with a variable voltage and frequency to motor 50. In other embodiments, motor 50 may be powered directly from an AC or direct current (DC) power source. Motor 50 can be any type of electric motor that can be powered by a VSD or directly from an AC or DC power source, such as a switched reluctance motor, induction motor, electronically commutated permanent magnet motor, or other May include a suitable motor.

Compressor 32 compresses the refrigerant vapor and delivers the vapor to the condenser 34 through a discharge passage. In some embodiments, compressor 32 may be a centrifugal compressor. Compressor 32 includes a fluid (eg, lubricating oil) that lubricates the components of the compressor. Refrigerant vapor delivered by compressor 32 to condenser 34 may transfer heat to a cooling fluid (e.g., water or air) within condenser 34. Refrigerant vapor may condense into refrigerant liquid within condenser 34 as a result of heat transfer with the cooling fluid. Refrigerant liquid from condenser 34 may flow through expansion device 36 to evaporator 38. In the illustrated embodiment of FIG. 3 , the condenser 34 is water cooled and includes a tube bundle 54 connected to a cooling tower 56 that supplies cooling fluid to the condenser.

The refrigerant liquid delivered to the evaporator 38 may absorb heat from another cooling fluid, which may or may not be the same cooling fluid used in the condenser 34. The refrigerant liquid within evaporator 38 may undergo a phase change from refrigerant liquid to refrigerant vapor. As shown in the illustrated embodiment of FIG. 3 , evaporator 38 may include a tube bundle 58 having a supply line 60S and a return line 60R connected to a cooling load 62 . Cooling fluid (e.g., water, ethylene glycol, calcium chloride brine, sodium chloride brine, or any other suitable fluid) of evaporator 38 enters evaporator 38 through return line 60R and supply line 60S. It exits the evaporator (38) through . The evaporator 38 can lower the temperature of the cooling fluid in the tube bundle 58 through heat transfer with the refrigerant. Tube bundle 58 within evaporator 38 may include multiple tubes and/or multiple tube bundles. In either case, the refrigerant vapor exits the evaporator 38 by the suction line and returns to the compressor 32 to complete the cycle.

4 is a schematic diagram of a vapor compression system 14 with an intermediate circuit 64 included between the condenser 34 and expansion device 36. The intermediate circuit 64 may have an inlet line 68 directly fluidly connected to the condenser 34. In other embodiments, inlet line 68 may be indirectly fluidically coupled to condenser 34. As shown in the illustrated embodiment of FIG. 4 , inlet line 68 includes a first expansion device 66 disposed upstream of intermediate vessel 70 . In some embodiments, intermediate vessel 70 may be a flash tank (eg, flash intercooler). In other embodiments, intermediate vessel 70 may be configured as a heat exchanger or “surface economizer.” In the illustrated embodiment of FIG. 4 , the intermediate vessel 70 is used as a flash tank and the first expansion device 66 is configured to lower the pressure (e.g., expand) the refrigerant liquid received from the condenser 34. ) is composed. During the expansion process, some of the liquid may evaporate, thus allowing the intermediate vessel 70 to be used to separate the vapor from the liquid received from the first expansion device 66 . Additionally, the intermediate vessel 70 may provide for additional expansion of the refrigerant liquid upon entering the intermediate vessel 70 (e.g., a rapid increase in volume that occurs upon entering the intermediate vessel 70). This is because a pressure drop occurs in the refrigerant liquid. The vapor within the intermediate vessel 70 may be withdrawn by the compressor 32 through the suction line 74 of the compressor 32. In other embodiments, the vapor within the intermediate vessel may be drawn to an intermediate stage (e.g., other than the suction stage) of compressor 32. The liquid collecting within intermediate vessel 70 may have a lower enthalpy than the refrigerant liquid exiting condenser 34 due to expansion within expansion device 66 and/or intermediate vessel 70. Liquid from intermediate vessel 70 may then flow in line 72 through second expansion device 36 to evaporator 38.

5 is a schematic diagram illustrating an embodiment of a lubrication circuit 80 that may be included in vapor compression system 14. As described above, vapor compression system 14 is comprised of a fluid (e.g., oil) circulated through compressor 32 to lubricate components (e.g., bearings and/or shafts) of compressor 32. (same lubricant) can be used. More specifically, the lubrication circuit 80 is configured to provide fluid for lubrication of various components by circulating fluid to various locations along the vapor compression system 14, such as to the compressor 32. Lubrication circuit 80 includes a sump 82 fluidically coupled to compressor 32 for collecting and/or storing fluid. After lubricating the components of compressor 32, fluid may flow through compressor drain conduit 84 toward sump 82 and accumulate within sump 82. As shown, lubrication circuit 80 includes a condenser drain conduit 86 and an evaporator drain configured to discharge fluid mixed with refrigerant and collected within condenser 34 and evaporator 38, respectively, to sump 82. Includes conduit 88. For example, the condenser drain conduit 86 and/or the evaporator drain conduit 88 may be configured to direct a fluid (e.g., oil or oil and refrigerant mixture) as a high pressure gas to the sump 82. In certain embodiments, fluid flowing along the condenser drain conduit 86 and/or along the evaporator drain conduit 88 may flow through an eductor 89 before entering the sump 82. You can. The eductor 89 may mix the fluid exiting the condenser 34 and evaporator 38 prior to entering the sump 82 and/or mix the fluid exiting the condenser 34 and evaporator 38. It can be guided towards the sump (82).

A pump 90 (e.g., a submerged pump and/or variable speed pump) is disposed within the sump 82 to direct fluid or a mixture of fluid and refrigerant through the compressor supply conduit 92 to the compressor 32. You can. In other embodiments, pump 90 may be located outside of sump 82 and/or between sump 82 and compressor 32. Additionally, in some embodiments, lubrication circuit 80 may include a cooler disposed along compressor drain conduit 84 and/or compressor supply conduit 92. The cooler may be configured to remove heat previously absorbed by the fluid from the fluid when lubricating the compressor 32.

In certain embodiments, pump 90 may be a variable speed electric pump such that pump 90 is configured to be adjustable to provide or enable a particular flow rate of fluid. For example, the pump 90 may receive a signal from the controller indicating an adjustment to the target flow rate of fluid within the lubrication circuit 80. The speed of the pump 90 can be adjusted based on the received signal so that the flow of fluid through the pump 90 reaches the target flow rate. As described herein, adjustments to the target flow rate may include proportional adjustments to the flow rate, linear adjustments, non-linear adjustments, exponential adjustments, other types of adjustments, or combinations thereof. By comparison, a mechanically driven pump (e.g., a pump driven to regulate flow rate through a shaft) may be configured to adjust flow rate linearly but not otherwise. Accordingly, the flow rate of fluid supplied by the pump 90 can be adjusted to a wider range of target flow rates compared to a mechanically driven pump.

In some embodiments, pump 90 may be a fixed speed pump, and the flow rate downstream of pump 90 may be adjusted through an electronic regulator or electronic bypass valve. For example, an electronic regulator or electronic bypass valve may be located between pump 90 and compressor 32 (e.g., along compressor supply conduit 92). The electronic controller or electronic bypass valve may receive a signal from the controller indicating an adjustment to the target flow rate of fluid within the lubrication circuit 80. In response, the operation of the electronic regulator or electronic bypass valve may be adjusted to cause the flow of fluid through the pump 90 to reach the target flow rate.

6 is a schematic diagram showing an embodiment of the lubrication circuit 80. As can be seen in the illustrated embodiment of FIG. 6 , compressor 32 includes a shaft 94 which rotates a rotor coupled to shaft 94 and causing the rotor to move within compressor 32. It is configured to compress the refrigerant. Shaft 94 is at least partially supported by bearings 96. Although the depicted embodiment shows compressor 32 with one bearing 96, in other embodiments, compressor 32 may have an additional bearing 96 configured to support shaft 94 (e.g., may include 2 bearings, 3 bearings, 4 bearings, 6 bearings, 10 bearings, etc.). A fluid film is formed between the shaft 94 and the bearings 96 such that a fluid (e.g., oil or other lubricant) is formed between the shaft 94 and the bearings 96 to lubricate the shaft 94 as the shaft 94 rotates. (96) It can fluctuate between. Fluid may enter compressor 32 through compressor fluid inlet 98 coupled to compressor supply conduit 92 and generally directed to bearing fluid inlet 100, as indicated by arrow 102. It can be. As indicated by arrow 104 (e.g., at the end of bearing 96), fluid may flow from bearing fluid inlet 100, between shaft 94 and bearing 96, and finally It can flow away from the bearing 96. After passing through bearing 96, fluid may flow to compressor fluid outlet 106, which is coupled to compressor drain conduit 84. Accordingly, fluid can be circulated from the sump 82, through the bearings 96, and back to the sump 82.

Vapor compression system 14 also includes a fluid pressure control system 110 configured to control the flow of fluid (e.g., lubricant) along lubrication circuit 80. For example, portions of the lubrication circuit 80 and the vapor compression system 14 may generally be controlled by the fluid pressure control system 110 based on feedback representative of operating parameters of the vapor compression system 14. You can. Specifically, vapor compression system 14 may be controlled based on feedback indicative of shaft speed (e.g., rotating shaft speed) of shaft 94 as detected by sensor 112. Sensor 112 is disposed proximate to shaft 94 and communicatively coupled to control panel 40, such that sensor 112 outputs a signal representative of shaft 94 speed to control panel 40. can do. Additionally or alternatively, vapor compression system 14 may be controlled based on feedback indicating the temperature of the fluid within compressor 32 at bearing 96 as detected by sensor 114. Sensor 114 is disposed proximate to bearing 96 and communicatively coupled to control panel 40 such that sensor 114 generates a signal indicative of the temperature within compressor 32 at bearing 96. It can be output to the control panel 40. In some embodiments, sensor 114 may be a thermocouple and/or other suitable device disposed proximate to bearing 96 and configured to provide feedback indicative of temperature.

In certain embodiments, fluid pressure control system 110 may include a sensor 116 disposed along compressor supply conduit 92 (e.g., along lubrication circuit 80 upstream of bearing 96). This sensor is configured to detect the fluid supply temperature of the fluid along the compressor supply conduit 92. Additionally or alternatively, sensor 116 may be disposed at compressor fluid inlet 98 and may be configured to detect the fluid supply temperature at compressor fluid inlet 98. Sensor 116 is communicatively coupled to control panel 40 and configured to output a signal representative of the fluid supply temperature to control panel 40.

In certain embodiments, fluid pressure control system 110 may include a sensor 118 disposed along compressor drain conduit 84 (e.g., along lubrication circuit 80 downstream of bearing 96). and configured to detect the fluid drain temperature of the fluid along the compressor drain conduit 84. Additionally or alternatively, sensor 118 may be disposed at compressor fluid outlet 106 and configured to detect the fluid drain temperature at compressor fluid outlet 106 . Sensor 118 is communicatively coupled to control panel 40 and configured to output a signal representative of fluid drain temperature to control panel 40 . Based on feedback indicating the fluid supply temperature and/or fluid drain temperature, the microprocessor 44 of control panel 40 determines (e.g., using instructions stored within memory 46) the The temperature within compressor 32 may be determined and/or calculated. For example, microprocessor 44 may determine compressor 32 at bearing 96 based on the difference between the fluid supply temperature and fluid drain temperature or other suitable algorithm using the fluid supply temperature and fluid drain temperature. ) can be calculated.

Microprocessor 44 may determine a target flow rate of fluid flowing from pump 90 to bearing 96 based on the shaft speed of shaft 94 and/or the temperature within the compressor at bearing 96. . For example, microprocessor 44 may determine a target flow rate of fluid as a function of shaft speed and/or temperature (e.g., a linear function, a non-linear function, a proportional function, an exponential function, or a combination thereof). You can. Additionally or alternatively, microprocessor 44 may determine the target flow rate based on a lookup table stored in memory 46. For example, a lookup table may list target flow rates as a function of corresponding shaft speed and/or temperature. In some embodiments, microprocessor 44 can interpolate values within a lookup table to determine the target flow rate. Also, in a further embodiment, the microprocessor 44 may provide input 130 to the interface board 48 (e.g., generally the properties of the fluid, the mode of operation of the compressor 32, and/or the vapor compression system 14 The target flow rate can be determined based on the input indicating the operating mode of ).

After determining the target flow rate, fluid pressure control system 110 may adjust the flow rate of fluid to the target flow rate (e.g., adjust the speed of pump 90 to control the pressure of fluid along lubrication circuit 80). can be adjusted). For example, microprocessor 44 may be communicatively coupled to sump 82 and pump 90 and control the flow rate of fluid to indicate adjustments to pump 90 to achieve a target flow rate. A signal can be output to the pump 90. In certain embodiments, microprocessor 44 may provide user-detectable notifications and/or alerts via display 132 of interface board 48 (e.g., a user interface). Indicator 132 may be any user-detectable notification, such as a light emitting diode (LED), an audible alert, a display, text, and/or other suitable notification. For example, user-detectable notifications and/or alerts may include the flow rate of fluid, target flow rate, difference between flow rate and target flow rate, temperature within compressor 32 at bearings 96, fluid along lubrication circuit 80. It can represent pressure, or a combination thereof.

In certain embodiments, fluid pressure control system 110 controls the flow rate of fluid in and/or exiting pump 90 (e.g., the speed of pump 90 and/or pump 90 ) may include a sensor 120 configured to provide feedback indicative of the discharge pressure) to the control panel 40. As shown, sensor 120 is coupled to pump 90 and disposed within sump 82. In other embodiments, sensor 120 may be disposed external to sump 82 and measures the flow rate of fluid flowing from pump 90 prior to entering compressor 32 (e.g., compressor supply conduit 92 ) and/or at the compressor fluid inlet 98.

Microprocessor 44 may compare the flow rate (e.g., the flow rate detected by sensor 120) to a target flow rate and control pump 90 based on such comparison. For example, if the difference between the flow rate and the target flow rate exceeds the threshold difference, microprocessor 44 outputs a signal to pump 90 (e.g., to increase the speed of pump 90 or (by reducing) the flow rate can be adjusted to the target flow rate. The threshold difference may be based on the type of fluid, operating parameters of the fluid, operating mode of compressor 32 and/or vapor compression system 14, operator input, or a combination thereof. Additionally or alternatively, the threshold difference may be a percentage difference between the flow rate and the target flow rate (e.g., 1 percent, 2 percent, 5 percent, 10 percent, etc.).

As shown, fluid pressure control system 110 is configured to receive feedback indicative of shaft speed and/or temperature, determine a target flow rate, and adjust the operation of pump 90 to achieve the target flow rate. and a control panel 40 of the vapor compression system 14. Additionally or alternatively, fluid pressure control system 110 may receive feedback indicative of shaft speed and/or temperature, determine a target flow rate, and adjust operation of pump 90 to achieve the target flow rate. It may include an additional controller configured to do so. For example, the additional controller may be a controller of lubrication circuit 80 and may be configured to control the flow of fluid along lubrication circuit 80.

In some embodiments, the memory 46 of the control panel 40 includes one or more tangible, non-data storing instructions that can be executed by the microprocessor 44 and/or data to be processed by the microprocessor 44. -May include temporary computer-readable media. For example, memory 46 may be random access memory (RAM), read-only memory (ROM), rewritable non-volatile memory, such as flash memory, hard drive, optical disk, other types of memory, or these. It may include a combination of . Additionally, microprocessor 44 may include one or more general-purpose microprocessors, one or more application specific integrated circuits (ASICs), one or more field programmable logic arrays (FPGAs), or any of these, to execute instructions stored in memory 46. It may include a combination of .

7 is a flow diagram illustrating an embodiment of a process 140 for operating fluid pressure control system 110. It will be understood that the steps described herein are illustrative only and that certain steps may be omitted or performed in an order other than that described below. In some embodiments, process 140 is stored in memory 46 and executed by microprocessor 44 of control panel 40, or other suitable memory and executed by microprocessor 44 of fluid pressure control system 110. It can be implemented by processing circuitry.

As seen in the illustrated embodiment of FIG. 7 , at block 142, fluid pressure control system 110, via microprocessor 44, monitors sensors disposed along lubrication circuit 80 (e.g., , receives feedback indicative of operating parameters from sensors 112, 114, 116, 118, and/or 120). The operating parameters include the speed of the shaft 94, the temperature within the compressor 32 at the bearings 96, the fluid supply temperature along the compressor supply conduit 92, the fluid drain temperature along the compressor drain conduit 84, and the pump ( 90), other operating parameters associated with the operation of the vapor compression system 14 (e.g., operating parameters of the refrigerant), or combinations thereof. As previously discussed, microprocessor 44 may be configured to determine the temperature within compressor 32 at bearing 96 based on the fluid supply temperature and/or fluid drain temperature.

At block 144, fluid pressure control system 110 adjusts the flow rate of fluid along lubrication circuit 80 based on feedback representative of operating parameters. For example, microprocessor 44 may provide feedback (e.g., speed of shaft 94, temperature within compressor 32 at bearing 96, fluid supply temperature along compressor supply conduit 92, compressor drain). A target flow rate of fluid is determined based on the fluid drain temperature along conduit 84, the flow rate of fluid in pump 90, other operating parameters associated with the operation of vapor compression system 14, or any combination thereof. A signal for adjusting the flow rate of the fluid to achieve the target flow rate can be output to the pump 90 (for example, a signal for adjusting the speed of the pump 90 can be output ). In certain embodiments, the microprocessor 44 may compare the measured or detected flow rate to a target flow rate and, in response to the difference between the flow rate and the target flow rate exceeding a threshold difference, adjust the flow rate of the fluid. A signal can be output to the pump 90.

In some embodiments, fluid pressure control system 110 may adjust the flow rate of fluid along lubrication circuit 80 based on the speed of shaft 94 and the temperature within compressor 32 at bearing 96. For example, microprocessor 44 may determine a target flow rate based on a target temperature within compressor 32 at bearing 96. Feedback indicative of the actual temperature within compressor 32 at bearing 96 may be received from sensors 114 , 116 , and/or 118 and based on the feedback from sensors 114 , 116 , and/or 118 It can be determined and/or received through input 130. When the actual temperature within the compressor 32 at the bearing 96 is outside the target temperature range, the microprocessor 44 can output a signal to the pump 90 to adjust the flow rate of the fluid. In some embodiments, memory 46 may store ranges of operating parameters (e.g., speed ranges) that allow pump 90 to operate effectively. When the microprocessor 44 determines that the pump 90 may be operated outside the range of the operating parameters due to the target flow rate of the fluid, the microprocessor 44 determines that the pump 90 is operated outside the upper limit of the range of the operating parameters. It can be instructed to operate at either a value or a lower limit value.

Similarly, microprocessor 44 may determine a target flow rate of fluid based on the speed of shaft 94. For example, microprocessor 44 may determine the target flow rate as a function of shaft speed (e.g., linear, proportional, exponential). In certain embodiments, microprocessor 44 may compare the measured flow rate to a target flow rate and adjust the flow rate of the fluid in response to the difference between the measured flow rate and the target flow rate exceeding a threshold difference. A signal can be output to the pump 90.

In certain embodiments, the microprocessor checks for feedback from sensors 114, 116, and/or 118 in cases where the target flow rate of fluid may cause pump 90 to operate outside of its operating parameters. to determine whether sensors 114, 116, and/or 118 are functioning correctly, whether pump 90, compressor 32, or vapor compression system 14 should be deactivated, or other control actions are performed. You can decide whether it should be done or not. For example, if feedback from sensor 114 (e.g., feedback indicating the temperature of the fluid in compressor 32 at bearing 96) corresponds to a first target flow rate that is outside the range of operating parameters. Alternatively, microprocessor 44 may determine whether feedback from a second sensor (e.g., sensor 116 or 118) corresponds to a second target flow rate that is also outside the range of operating parameters. In cases where both the first and second target flow rates may cause pump 90 to operate outside the range of operating parameters, microprocessor 44 may control pump 90, compressor 32, and/or vapor compression system. A control signal may be output to stop the operation of (14) or to perform other control operations. In cases where the pump 90 may operate outside the range of operating parameters due to either the first or the second target flow rate, the microprocessor 44 outputs a signal to the control panel 40 to determine the sensor 114, 116, and/or 118) state/condition (e.g., sensors 114, 116, and/or 118 may not operate properly).

8 is a flow diagram illustrating an embodiment of a process 150 for operating fluid pressure control system 110. It will be understood that the steps described herein are illustrative only and that certain steps may be omitted or performed in an order other than that described below. In some embodiments, process 150 may be stored in memory 46 and executed by microprocessor 44 of control panel 40, or may be stored in other suitable memory and other suitable processing circuitry. It can be executed by

As seen in the embodiment shown in FIG. 8 , at block 152, fluid pressure control system 110, via microprocessor 44, controls fluid properties (e.g., fluid in lubrication circuit 80). receives input(s) indicating the operating characteristics of the fluid, the type of fluid, and the operating characteristics of other fluids within the vapor compression system 14. For example, the input may include input 130 provided on interface board 48.

At block 154, microprocessor 44 receives feedback from sensor 112 indicating the speed of shaft 94. At block 156, microprocessor 44 determines a target flow rate of fluid to bearing 96 based on the speed of shaft 94. For example, microprocessor 44 may determine a target flow rate of fluid as a function of the speed of shaft 94 (e.g., a linear function, a non-linear function, a proportional function, an exponential function, or a combination thereof). and/or the target flow rate may be determined based on the speed of the shaft 94 by reference to a lookup table.

At block 158, fluid pressure control system 110 adjusts the operation of pump 90 (e.g., the speed of pump 90 and/or the position/angle of the swashplate of pump 90). Adjust the flow rate of the fluid and achieve the target flow rate. For example, fluid pressure control system 110 can determine a target speed of pump 90 at which the target flow rate can be achieved, compare the target speed to a range of operating speeds of pump 90, and compare the target speed to a range of operating speeds of pump 90. Based on this, the operating speed of the pump 90 can be selected from the range of operating speeds, and the operation of the pump 90 can be adjusted to the selected operating speed. In certain embodiments, microprocessor 44 may compare the measured flow rate to a target flow rate and adjust the flow rate of the fluid in response to the difference between the measured flow rate and the target flow rate exceeding a threshold difference. A signal can be output to the pump 90.

9 is a flow diagram illustrating an embodiment of a process 160 for operating fluid pressure control system 110. It will be understood that the steps described herein are illustrative only and that certain steps may be omitted or performed in an order other than that described below. In some embodiments, process 160 may be stored in memory 46 and executed by microprocessor 44 of control panel 40, or may be stored in other suitable memory and other suitable processing circuitry. It can be executed by

As seen in the embodiment shown in FIG. 9 , at block 162, fluid pressure control system 110, via microprocessor 44, controls fluid properties (e.g., fluid in lubrication circuit 80). receives input(s) indicating the operating characteristics of the fluid, the type of fluid, and the operating characteristics of other fluids within the vapor compression system 14. In some embodiments, feedback may include input 130 provided to interface board 48 by, for example, a user.

At block 164, microprocessor 44 receives feedback from sensor 114, which may include feedback indicative of the temperature of the fluid in compressor 32 at bearing 96. Additionally or alternatively, microprocessor 44 may receive a fluid supply temperature from sensor 116 and/or a fluid drain temperature from sensor 118 and perform a function based on the fluid supply temperature and/or fluid drain temperature. It is possible to determine the temperature of the fluid in the compressor 32 at the bearing 96.

At block 166, microprocessor 44 determines a target flow rate of fluid from pump 90 to bearing 96 based on the temperature within compressor 32 at bearing 96. For example, microprocessor 44 may determine a target flow rate of fluid as a function of temperature at bearing 96 (e.g., a linear function, a non-linear function, a proportional function, an exponential function, or a combination thereof). A target flow rate can be determined and/or referenced to a lookup table to determine the target flow rate based on the temperature at bearing 96.

At block 168, fluid pressure control system 110 adjusts the operation of pump 90 to control the flow rate of fluid and achieve a target flow rate. For example, fluid pressure control system 110 can determine a target speed of pump 90 at which the target flow rate can be achieved, compare the target speed to a range of operating speeds of pump 90, and compare the target speed to a range of operating speeds of pump 90. Based on this, the operating speed of the pump 90 can be selected from the range of operating speeds, and the operation of the pump 90 can be adjusted to the selected operating speed. In certain embodiments, microprocessor 44 may compare the measured flow rate to a target flow rate and adjust the flow rate of the fluid in response to the difference between the measured flow rate and the target flow rate exceeding a threshold difference. A signal can be output to the pump 90.

Although processes 140, 150, and 160 are described herein as separate processes, processes 140, 150, and 160, or specific steps thereof, may be combined into a single process or method. For example, fluid pressure control system 110 may perform steps of processes 140, 150, and 160 simultaneously or independently. In certain embodiments, as described above, the fluid pressure control system 110 controls the flow of fluid along the lubrication circuit 80 as a function of both the speed of the shaft 94 and the temperature of the fluid within the compressor 32 at the bearings 96. The flow rate of fluid can be controlled.

Accordingly, the present disclosure relates to a fluid pressure control system for lubricating various components of a compressor. The fluid pressure control system includes sensors that provide feedback indicative of the speed of the shaft of the compressor and/or the temperature within the compressor at the bearings. For example, a first sensor may be placed proximate to the shaft and configured to provide feedback indicative of the speed of the shaft. A second sensor may be disposed proximate the bearing and may be configured to provide feedback indicative of the temperature within the compressor at the bearing. In certain embodiments, a sensor may be disposed in a compressor supply conduit of the compressor and/or a compressor drain conduit of the compressor and may be configured to detect the fluid supply temperature and fluid drain temperature of the fluid, respectively. Accordingly, the controller of the fluid pressure control system may determine the temperature within the compressor at the bearing based on the fluid supply temperature and/or fluid drain temperature.

Additionally, the controller may control the flow rate of fluid from the pump to the bearing by adjusting the operating parameters of the pump based on the speed of the shaft and/or the temperature within the compressor at the bearing. For example, the controller may determine a target flow rate based on the speed of the shaft and/or temperature at the bearings and may adjust the pump to achieve the target flow. In some embodiments, the target flow rate may be a function of the speed of the shaft and/or the temperature at the bearing (e.g., a linear function, a non-linear function, a proportional function, an exponential function, or a combination thereof). When the speed of the shaft and/or the temperature at the bearings are reduced, the controller can generally adjust the operation of the pump to reduce the flow rate. When the speed of the shaft and/or the temperature at the bearings increases, the controller can generally adjust the operation of the pump to increase flow rate. In some cases, the controller may adjust the operation of the pump to adjust the flow rate of the fluid, which may improve the overall operation and efficiency of the compressor and/or vapor compression system. For example, controlling the flow rate can at least partially block or reduce leakage of fluid from seals of the compressor and/or reduce friction between the fluid, shaft, and/or bearings.

Although only certain features and embodiments of the invention have been illustrated and described, many modifications and variations (e.g., sizes, dimensions, and structures of various elements) can be made without departing substantially from the novel teachings and advantages of the subject matter as set forth in the claims. , shape and proportion, values of parameters (e.g., temperature, pressure, etc.), mounting arrangement, use of materials, color, orientation, etc.) may be made by those skilled in the art. The order or sequence of any process or method steps may be altered or rearranged in accordance with alternative embodiments. Accordingly, it is to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. Additionally, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not be described (i.e., those that are not relevant to the currently considered best mode of carrying out the invention, or the claimed invention). things that are not related to enabling). It should be understood that, as in any engineering technique or design scheme, in the development of any such practical implementation, many implementation-specific decisions may be made. Additionally, while such a development effort may be complex and time consuming, it will nonetheless be a routine design, fabrication, and manufacturing task for those skilled in the art to benefit from the present disclosure without undue experimentation.

Claims (20)

A fluid pressure control system for a compressor, comprising:
a pump configured to direct lubricant toward the bearings of the compressor;
a sensor configured to provide feedback indicative of a speed of a shaft of the compressor, wherein the shaft is configured to be supported at least partially by the bearing; and
A non-transitory computer-readable medium containing executable instructions that, when executed by a processor, cause the processor to:
receive a signal representing the speed of the shaft from the sensor;
determine a target flow rate of the lubricant based on the speed of the shaft; and
adjusting operation of the pump based on the target flow rate such that the flow rate of the lubricant toward the bearing of the compressor approaches the target flow rate.
Fluid pressure control system. In claim 1,
wherein the executable instructions, when executed by the processor, are configured to cause the processor to determine a target flow rate of the lubricant based on the speed of the shaft using a proportional function. In claim 1,
The executable instructions, when executed by the processor, are configured to cause the processor to determine the target flow rate of the lubricant based on the speed of the shaft using an exponential function. In claim 1,
A fluid pressure control system, wherein the sensor is disposed proximate an end of the shaft. In claim 1,
A fluid pressure control system comprising the bearing, wherein the lubricant is configured to form a film between the bearing and the shaft. In claim 1,
A fluid pressure control system, wherein the pump comprises an electric pump. 2. The fluid pressure control system of claim 1, comprising a flow sensor, the flow sensor configured to provide feedback indicative of the flow rate of the lubricant directed toward the bearing of the compressor. A fluid pressure control system for a compressor, comprising:
a pump configured to direct lubricant toward the bearings of the compressor;
a sensor configured to provide feedback indicative of the temperature within the compressor at the bearing; and
At least one non-transitory computer-readable medium containing executable instructions that, when executed by a processor, cause the processor to:
receive a signal from the sensor indicating the temperature within the compressor at the bearing;
determine a target flow rate of the lubricant based on the temperature in the compressor at the bearing; and
A fluid pressure control system, comprising a non-transitory computer-readable medium configured to adjust operation of the pump based on the target flow rate such that the flow rate of lubricant toward the bearings of the compressor approaches the target flow rate. In claim 8,
a fluid pressure comprising a lubrication circuit, wherein the pump and the compressor are disposed along the lubrication circuit, the lubrication circuit configured to direct the lubricant from the pump toward the bearing and from the bearing toward the pump. control system. In claim 9,
The sensor includes a first sensor disposed along the lubrication circuit and configured to output a first signal indicative of a fluid supply temperature of the lubricant along the lubrication circuit upstream of the bearing, and a first sensor disposed along the lubrication circuit and downstream of the bearing. A fluid pressure control system comprising a second sensor configured to output a second signal indicative of a fluid drain temperature of the lubricant along a lubrication circuit. In claim 10,
wherein the executable instructions, when executed by the processor, are configured to cause the processor to determine a temperature in the compressor at the bearing based on the fluid supply temperature and the fluid drain temperature. In claim 8,
wherein the executable instructions, when executed by the processor, are configured to cause the processor to output an additional signal to the interface board that causes the temperature in the compressor at the bearing to be displayed on a display of the interface board. . In claim 8,
A fluid pressure control system, wherein the sensor is disposed proximate to the bearing. In claim 13,
wherein the sensor includes a thermocouple configured to output a signal indicative of the temperature within the compressor at the bearing. 9. The fluid pressure control system of claim 8, comprising a flow sensor, the flow sensor configured to provide feedback indicative of the flow rate of the lubricant directed toward the bearing of the compressor. A fluid pressure control system for a compressor, comprising:
a pump configured to direct lubricant toward the bearings of the compressor;
a first sensor configured to provide feedback indicative of a speed of a shaft of the compressor, the shaft configured to be supported at least partially by the bearing; and
a second sensor configured to provide feedback indicative of the temperature within the compressor at the bearing; and
At least one non-transitory computer-readable medium containing executable instructions that, when executed by a processor, cause the processor to:
receive a first signal representing the speed of the shaft from the first sensor;
receive a second signal from the second sensor indicating a temperature within the compressor at the bearing;
determine a target flow rate of the lubricant based on the speed of the shaft and the temperature of the compressor at the bearing; and
and adjust operation of the pump based on the target flow rate such that the flow rate of the lubricant toward the bearings of the compressor approaches the target flow rate. In claim 16,
The executable instructions, when executed by the processor, cause the processor to:
determine a target speed of the pump to achieve the target flow rate; and
and compare a target speed of the pump to achieve the target flow rate with an operating range of speeds of the pump. In claim 16,
The executable instructions, when executed by the processor, cause the processor to:
A fluid pressure control system configured to determine a target flow rate of the lubricant based on a temperature in the compressor at the bearing exceeding a target temperature range. In claim 18,
wherein the executable instructions, when executed by the processor, are configured to cause the processor to determine a target temperature range based on input received through an interface board. 17. The fluid pressure control system of claim 16, comprising a flow sensor, the flow sensor configured to provide feedback indicative of the flow rate of the lubricant directed toward the bearing of the compressor.