Inlet guide vane actuator assembly

Abstract

An inlet guide vane assembly for a centrifugal compressor comprises a plurality of guide vanes, a drive structure coupled to the plurality of guide vanes, an actuator, and an actuating mechanism. Rotation of the drive structure transforms the plurality of guide vanes from a first position to a second position. The actuating mechanism is configured to transform the plurality of guide vanes between the first position and the second position based on operation of the actuator. When the guide vane is in the first position, the actuating mechanism applies a first amount of rotational force to drive the drive structure, and when the guide vane is in the second position, the actuating mechanism applies a second amount of rotational force. When the guide vane is in the first position, the actuating mechanism provides a mechanical advantage to the actuator compared to when the guide vane is in the second position.

Description

Technical Field

[0001] This application claims priority to U.S. Provisional Application No. 62 / 928,881, filed on October 31, 2019, the entire contents of which are incorporated herein by reference in their entirety.

[0002] The present invention relates generally to inlet guide vanes, and more particularly to an actuator assembly for opening and / or closing inlet guide vanes in HVAC and refrigeration equipment. Background Art

[0003] This section is intended to introduce the reader to various aspects of the art that may be related to various aspects of the presently described embodiments, to help facilitate a better understanding of the various aspects of the present embodiments. Therefore, it should be understood that these statements should be understood from this perspective, rather than as admissions of prior art.

[0004] Modern residential and industrial customers desire climate control for indoor spaces. Typically, a heating, ventilation, and air conditioning ("HVAC") system regulates the ambient air temperature of an indoor space by circulating air in the indoor space through a low-temperature (for cooling) source or a high-temperature (for heating) source. HVAC systems generate these low-temperature and high-temperature sources by utilizing, among other techniques, the following well-known physical principles: a fluid transitioning from a gas to a liquid releases heat, while a fluid transitioning from a liquid to a gas absorbs heat.

[0005] In a typical residential system, a fluid refrigerant circulates through a closed loop of pipes that uses compressors and other flow control devices to manipulate the flow and pressure of the refrigerant so that the refrigerant cycles between a liquid and a vapor phase. These phase changes typically occur within the HVAC's heat exchanger, which is part of the closed loop and is designed to transfer heat between the circulating refrigerant and the flowing ambient air. This is the basis of the refrigeration cycle. The heat exchanger in which the refrigerant changes from a gas to a liquid is called a "condenser," and the condensing fluid gives up heat to the surrounding environment. The heat exchanger in which the refrigerant changes from a liquid to a gas is called an "evaporator," and the evaporated refrigerant absorbs heat from the surrounding environment.

[0006] For commercial applications, centrifugal chillers are an economical way to control the indoor climate of large buildings. In a typical chiller system, multiple fluid circuits work together to transfer heat from one location to another. The core of a typical chiller is a refrigerant circuit that circulates a fluid refrigerant that transitions between a liquid phase and a gas phase to achieve the absorption or release of the required heat. This is similar to a traditional residential system. However, instead of a refrigerant that transfers heat directly to or absorbs heat directly from the surrounding air or circulating air, a chiller typically uses a circuit of circulating water to which or from which heat is transferred. In order to cool a building, the evaporator of the refrigerant circuit can be designed to absorb heat from water circulating in a cooling water circuit, which in turn absorbs heat from the indoor environment via a heat exchanger in an air handling unit. And the condenser of the refrigerant circuit can be designed to release heat from the circulating refrigerant to the water circulating in the cooling water circuit, which in turn releases heat to the outdoor environment via a heat exchanger in a cooling tower.

[0007] The circulation of refrigerant within the refrigerant circuit may be driven in part by a centrifugal compressor having inlet guide vanes (IGVs) that open and close to vary the refrigerant flow entering the compressor, thereby regulating the cooling capacity of the chiller. As the inlet guide vanes begin to close, the inlet guide vanes change the angle of entry to the impeller, reducing the flow rate and the cooling capacity of the chiller. In some applications, the gaseous refrigerant impacting the guide vanes may generate a torque that resists the IGV from moving from a more closed position to a more open position. Typically, this resistive torque is highest when the IGV is at or very close to the closed position, and may decrease as the IGV transitions to the open position.

[0008] To overcome the maximum resistive torque, more powerful actuators can be used. However, these more powerful actuators are typically larger, more expensive, and require more energy to operate. Summary of the invention

[0009] Certain aspects of some embodiments disclosed herein are set forth below. It should be understood that presenting these aspects is merely to provide the reader with a brief overview of some forms that the present invention may take, and these aspects are not intended to limit the scope of the present invention. In fact, the present invention may include various aspects that may not be set forth below.

[0010] Embodiments of the present disclosure are generally directed to heating, ventilation, air conditioning, or refrigeration (HVACR) systems utilizing a centrifugal compressor having an inlet guide vane actuator assembly for opening and / or closing an IGV.

[0011] In some embodiments, the IGV is coupled to an assembly utilizing a worm drive and a linkage component arranged to create a mechanical advantage. In some embodiments, the IGV actuator assembly includes: a plurality of guide vanes; a drive structure coupled to the plurality of guide vanes, wherein rotation of the drive structure transitions the plurality of guide vanes from a first position to a second position; an actuator; an actuation mechanism configured to transition the plurality of guide vanes between the first position and the second position based on operation of the actuator, wherein when the guide vanes are in the first position, the actuation mechanism applies a first amount of rotational force to drive the drive structure, and when the guide vanes are in the second position, the actuation mechanism applies a second amount of rotational force, and wherein the actuation mechanism provides a mechanical advantage to the actuator when the guide vanes are in the first position compared to when the guide vanes are in the second position.

[0012] In some embodiments, a mechanical advantage increases the force applied to the drive ring and / or the IGV when the IGV is in a substantially closed position. In some embodiments, less actuator torque is required when the IGV is in a substantially closed position. In some embodiments, the connecting rod has an "over-center" design, wherein more force is applied to the drive ring when the connecting rod is closer to being parallel to the plane of the drive ring than when the connecting rod is less parallel to the plane of the drive ring.

[0013] With respect to various aspects of the present embodiment, there may be various improvements of the above-mentioned features. Other features may also be incorporated into these various aspects. These improvements and additional features may exist alone or in any combination. For example, the various features discussed below with respect to one or more of the illustrated embodiments may be incorporated into any of the above-mentioned aspects of the present disclosure alone or in any combination. Likewise, the brief overview given above is intended only to familiarize the reader with certain aspects and contexts of some embodiments, and is not limited to the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] These and other features, aspects and advantages of certain embodiments will become better understood when the following detailed description is read with reference to the accompanying drawings, in which like characters refer to like parts throughout the several views, and in which:

[0015] [ Figure 1 ] Figure 1 schematically illustrates a chiller system for a building according to one embodiment of the present disclosure;

[0016] [ FIG. 2A to FIG. 2B ] FIG. 2A to FIG. 2B schematically illustrates an IGV actuator assembly installed within a portion of a centrifugal cooler according to an embodiment of the present disclosure;

[0017] [ FIG. 3A to FIG. 3C ] FIG. 3A to FIG. 3C schematically illustrates an open position and a closed position of an IGV according to an embodiment of the present disclosure;

[0018] [ Figure 4 ] Figure 4 schematically illustrates an IGV actuator assembly according to an embodiment of the present disclosure;

[0019] [ Figure 5 ] Figure 5 schematically illustrates an IGV actuator assembly according to an embodiment of the present disclosure;

[0020] [ FIG. 6A to FIG. 6J ] FIG. 6A to FIG. 6J schematically illustrates the operation of an IGV actuator assembly according to an embodiment of the present disclosure; and

[0021] [ Figure 7 ] Figure 7 The relationship between torque and blade angle in an IGV actuator assembly according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0022] One or more specific embodiments of the present disclosure will be described below. In order to provide a concise description of these embodiments, all features of the actual implementation may not be described. It should be understood that in the development of any such actual implementation, as in any engineering or design project, many implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, and the developer's specific goals may vary from implementation to implementation. In addition, it should be understood that such development efforts may be complex and time-consuming, but for ordinary technicians who benefit from the present disclosure, this will be a routine task of design, manufacture and production.

[0023] When introducing elements of various embodiments, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0024] Go to the attached picture, Figure 1An overview of a chiller system 100 is shown. At the heart of the chiller is a refrigeration circuit 110. A compressor 120 converts relatively cold, low-pressure refrigerant gas into hot, high-pressure gas. The hot, high-pressure gas is then converted into a high-pressure liquid refrigerant in a condenser 125. During this step, heat from the high-pressure gas is typically transferred to water circulating in a cooling water circuit 130 via a heat exchanger in the condenser 125. Ultimately, the heat transferred to the water in the cooling water circuit 130 is rejected to the outdoor environment via another heat exchanger in a cooling tower 140.

[0025] The now liquid refrigerant leaving the condenser 125 in the refrigerant circuit is converted to a low pressure liquid as it passes through the expansion valve 127. This pressure drop also reduces the temperature of the refrigerant as the refrigerant becomes a low pressure liquid. The cold low pressure liquid then enters the evaporator 145 where heat is transferred back to the refrigerant, converting the refrigerant back to a low pressure gas to be compressed by the compressor. The heat transferred to the refrigerant in the evaporator 145 is typically provided by water circulating in a chilled water circuit 150 via a heat exchanger in the evaporator 145. The chilled water circuit 150 carries the now cooled water to an air handling unit (AHU) 160 which circulates the indoor air of the building through the heat exchanger to cool the indoor space. It is contemplated that the refrigerant may be any number of refrigerants including R410A, R32, R454B, R452B, R1233zd, R1234ze, R134a, R513A, R515A, R515B and R1234yf, or any number of combinations thereof.

[0026] Figure 2A An IGV actuator assembly 200 is schematically shown installed within a portion of a centrifugal compressor 210 . Figure 2B The IGV actuator assembly 200 is schematically shown installed within a centrifugal compressor 210, wherein a portion of the compressor is removed to illustrate the arrangement of one embodiment of the IGV actuator assembly 200 within the centrifugal compressor 210. The IGVs of the IGV actuator assembly 200 direct the airflow within the centrifugal compressor 210 incorporated into the chiller system. In other words, the IGVs of the IGV actuator assembly 200 impact the airflow within the centrifugal compressor 210 incorporated into the chiller system.

[0027] A centrifugal compressor operates by drawing gas through inlet guide vanes and compressing the gas using a centrifugal impeller. The airflow into the centrifugal compressor is regulated by opening and closing the IGV.

[0028] FIG. 3A to FIG. 3C The IGV 310 is shown as it transitions from an open position to a closed position. Figure 3AThe IGV 310 is shown in a fully open position. In this position, gas is allowed to flow through the blades substantially unrestricted. Figure 3B The IGV 310 is shown once rotated to a partially closed position. In this position, gas is allowed to flow through the vanes, but is restricted to a certain extent. The vanes also serve to direct the airflow so as to facilitate the rotational movement of the gas entering the centrifugal compressor. Figure 3C The IGV 310 is shown in a fully closed position. In this position, the flow of gas is significantly restricted. In some IGV assemblies, the central portion of the IGV remains open to allow minimal refrigerant flow even when the IGV is in the closed position.

[0029] Figure 4 Schematically illustrated is an IGV actuator assembly 400 according to one embodiment. As shown, the assembly 400 allows for control of the position of a plurality of IGVs 410. The plurality of IGVs 410 open and / or close in coordinated movement to restrict or expand the flow of fluid through the IGVs 410 into the centrifugal compressor.

[0030] In the disclosed assembly, the IGV 410 is coupled to a drive structure 420 that controls the opening and closing of the IGV 410. In some embodiments, the drive structure 420 includes a drive ring 422. In some embodiments, the drive structure 420 is connected to an actuation mechanism 430 that applies a force to the drive structure 420 so that the IGV 410 is opened or closed. The actuation mechanism 430 can apply a rotational force to the drive ring 422. The actuation mechanism 430 is driven by an actuator 440.

[0031] Figure 5 An IGV actuator assembly 500 is schematically illustrated according to one embodiment. In one disclosed embodiment, the IGV actuator assembly 500 is driven by a worm drive 530. The worm drive 530 includes a driven worm screw 534 that is used to rotate a worm gear 536 mounted on a central hub 538. The worm drive 530 is driven by a worm actuator 540. A link arm 550 is connected to the worm gear 536 at a first end 552 and to the drive ring 522 at a second end 554. (As used herein, "end" does not refer to a terminal position, but rather to a position closer to one side than the other.) The point at which the link arm 550 connects to the worm gear 536 is referred to as a first point 562. The point at which the link arm 550 connects to the drive ring 522 is referred to as a second point 564.

[0032] When the worm screw 534 is driven, the worm screw 534 rotates the worm wheel 536. The rotation of the worm wheel 536 transmits force through the link arm 550, causing the drive ring 522 to rotate, thereby opening or closing the IGV 510. That is, the drive ring 522 is operably connected to the IGV 510 and is configured to rotate the IGV 510 between the open position and the closed position. In other words, the drive ring 522 is operably connected to the IGV 510 and is configured to open and close the IGV 510.

[0033] In some embodiments, a mechanical advantage can be created based on a particular configuration of the worm wheel, the linkage arm, and the drive ring. The linkage arm converts a rotation of the worm wheel into a rotation of the drive ring. In some embodiments, the worm wheel and the drive ring are positioned substantially perpendicularly relative to each other. In other words, the worm drive includes a worm wheel disposed substantially perpendicular to the drive ring. In some embodiments, the amount of rotation imparted to the drive ring per unit rotation of the worm wheel depends on the position of the first point and / or the relative angle between the drive ring and the worm wheel.

[0034] For example, when the first point is most perpendicularly offset from the plane defined by the drive ring (i.e., the first plane), each unit rotation of the worm wheel translates into a greater amount of travel of the first point in a direction parallel to the first plane, thereby causing the linkage arm to rotate the drive ring a greater amount, but reducing the mechanical advantage of the linkage system. When the first point rotates with the worm wheel and approaches the plane defined by the drive ring, each unit rotation of the worm wheel translates into a reduced amount of travel of the first point in a direction parallel to the first plane, thereby causing the linkage arm to rotate the drive ring a smaller amount, but increasing the mechanical advantage of the linkage system. As a result of this arrangement, a greater amount of force can be applied to the drive ring when the first point is closer to the plane than when the first point is further away from the first plane.

[0035] In some embodiments, the linkage arm generally defines a first line that intersects a first plane defined by the drive ring. In such embodiments, as the gear rotates, the acute angle formed between the first line and the first plane will increase or decrease. In some embodiments, the mechanical advantage is greater when the acute angle is smaller than when the acute angle between the first line and the first plane is larger. In some embodiments, when the plurality of guide vanes are closed, the acute angle between the first plane and the first line is smaller, and when the plurality of guide vanes are opened, the acute angle between the first plane and the first line is larger.

[0036] FIG. 6A to FIG. 6J The movement of an IGV actuator assembly 600 is schematically illustrated according to one embodiment. Fig. 6AIGV 610 is shown in a substantially closed position. In this position, the gas passing through IGV 610 exerts a maximum force on the IGV, thereby creating resistance to opening the IGV. The first point 615 is substantially adjacent to the first plane 605 defined by the drive ring 620 (see Figure 6C ), thereby creating an increased mechanical advantage when the IGV 610 is closed and encounters the greatest amount of resistance from the flowing gas.

[0037] Figure 6B The assembly 600 is shown when the worm screw rotates the worm wheel approximately 10° clockwise. This rotation moves the first point 615 almost completely in a direction perpendicular to the first plane, resulting in only minimal rotation of the drive ring and a small amount of opening of the IGV 610. It can be appreciated that the worm screw rotates substantially the same amount to rotate the circular worm wheel 10° regardless of the position of the first point 615. However, the force applied by the linkage arm to the drive ring varies significantly depending on the position of the first point 615.

[0038] FIG. 6C to FIG. 6H In each figure, the assembly 600 is shown when the worm screw rotates the worm wheel approximately 10° clockwise. In each figure, the first point 615 rotates clockwise with the worm wheel. Although the worm wheel rotates approximately 10° in each figure, the first point 615 travels in a direction that is more parallel to the first plane 605 and less perpendicular to the first plane 605 in each consecutive figure. This results in the first point 615 rotating with the worm wheel to a point farther away from the first plane. FIG. 6C to FIG. 6H , the amount of rotation of the drive ring increases with each 10° rotation of the link arm. As shown in the figure, the acute angle formed between the link arm and the first plane 605 increases with each 10° rotation.

[0039] Fig.6I The assembly 600 is shown when the worm screw has rotated the worm gear approximately 80° and the first point is close to maximum offset from the first plane 605. In this position, each 10° rotation of the worm gear moves the first point 615 in a direction almost completely parallel to the first plane 605, so the link arm causes a significant rotation of the drive ring 620. The IGV 610 is essentially open in this position, allowing gas to enter the centrifugal compressor with relatively little resistance. Since the flowing gas does not provide significantly increased resistance when the assembly is in this configuration, the increased mechanical advantage created by the assembly is not required.

[0040] Figure 6J shows that when the worm screw has moved the worm wheel from Fig. 6A600 when the configuration shown in FIG. 6 is rotated approximately 90° and the first point 615 is maximally offset from the first plane 605. The IGV is fully open to allow relatively free flow of gas into the centrifugal compressor. In this position, the flowing gas does not create significant resistance to the movement of the IGV 610. The mechanical advantage created by the assembly is minimized in this position.

[0041] Figure 7 A graph showing the relationship between blade angle and actuator torque for an IGV actuator assembly according to one embodiment is shown. As shown in the graph, in some embodiments, the blade torque reaches a peak when the blade is in the closed position and the blade angle approaches zero degrees. Due to the mechanical advantage created by the disclosed mechanism, the required actuator torque decreases as the blade angle approaches zero, but the total blade torque increases as the blade angle approaches zero. Figure 7 As shown, when the angle of the guide vane relative to the drive ring decreases, the difference between the torque generated by the actuator and the torque applied to the guide vane increases. Figure 7 It is shown that the amount of force applied by the linkage arm to the drive ring is greater when the guide vanes are in the closed position than when the guide vanes are in the open position.

[0042] like Figure 7 As shown, in some embodiments, when the guide vane is in the first position, the actuation mechanism applies a first amount of rotational force to drive the drive structure, which is converted into blade torque, and when the guide vane is in the second position, the actuation mechanism applies a second amount of rotational force. In some embodiments, the actuation mechanism provides a mechanical advantage to the actuator when the guide vane is in the first position compared to when the guide vane is in the second position.

[0043] While the general concepts of the disclosed IGV actuator assembly have been discussed in the context of several specific embodiments, it should be appreciated that many variations are contemplated.

[0044] The disclosed embodiments include a plurality of guide vanes, a drive structure, and an actuation mechanism. In some embodiments, the drive structure includes a drive ring or any other suitable structure capable of receiving force from the actuation mechanism and adjusting the position of the plurality of guide vanes.

[0045] In some embodiments, the actuator mechanism may include a worm drive, a pulley drive, a belt drive, or a rack and pinion drive. In some embodiments, the actuator mechanism includes a gear, which may be, for example, a spur gear, a worm gear, a helical gear, a bevel gear, a wheel, or any suitable component configured to receive an actuating force and apply a force (e.g., a rotational force) to a drive structure or a drive ring. In some embodiments, the gear is mounted on a central hub. In some embodiments, the gear is arranged to be substantially perpendicular to the drive structure or the drive ring. In some embodiments, the gear is arranged to be at an angle greater than 45 ° with the drive structure or the drive ring. In some embodiments, the gear is elliptical. In some embodiments, the actuator mechanism includes a plurality of gears that can be engaged with each other and / or rotatably linked by a hub.

[0046] In some embodiments, the actuator mechanism includes a link arm. In some embodiments, the link arm has a first end and a second end, the first end is connected to a gear or wheel at a first point, and the second end is connected to a drive structure or a drive ring at a second point. In some embodiments, the link arm transmits force from the gear or wheel of the actuator mechanism to the drive structure or the drive ring. In some embodiments, the link arm includes one or more hinged or pivoted attachment points arranged to accommodate the movement of both the actuator assembly and the drive structure. In some embodiments, the movement of the drive ring forms an arc. In such an embodiment, the second point moves in the movement of the arc and also rotates with the drive ring. The link arm must accommodate each of these movements while also maintaining a rotational connection with the gear at the first point. In some embodiments, the link arm is arranged to provide both pulling and thrust. In some embodiments, more than one link arm can be used. In such an embodiment, each link arm can be arranged to provide thrust or pulling.

[0047] In some embodiments, the actuator mechanism is driven by an actuator. The actuator can be an electric actuator, a pneumatic actuator, a hydraulic actuator, a magnetic actuator, or a motor. In some embodiments, the actuator engages the gears using a worm screw, a rack, a chain drive, and / or a belt drive. In some embodiments, the actuator engages the gears through an intermediate mechanism, such as a series of gears or a central hub.

[0048] Although aspects of the present disclosure may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. It should be understood, however, that the present invention is not intended to be limited to the specific forms disclosed. On the contrary, the present invention will cover all modifications, equivalents and substitutions that fall within the spirit and scope of the present invention as defined by the appended claims.

[0049] Reference numerals list

[0050] 200: IGV actuator assembly

[0051] 310: IGV

[0052] 400: IGV actuator assembly

[0053] 410: IGV

[0054] 420: Drive structure

[0055] 422: Drive ring

[0056] 430: Actuation mechanism

[0057] 440: Actuator

[0058] 500: IGV actuator assembly

[0059] 510: IGV

[0060] 522: Drive ring

[0061] 530: Worm gear drive

[0062] 534: Driven worm screw

[0063] 536: Worm gear

[0064] 538: Central Hub

[0065] 540: Worm actuator

[0066] 550: Link arm

[0067] 552: First End

[0068] 554: Second end

[0069] 562: First point

[0070] 564: Second point

[0071] 600: Components

[0072] 605: First Plane

[0073] 610: IGV

[0074] 615: First point

[0075] 620: Drive ring

Claims

1. An inlet guide vane assembly for a centrifugal compressor, the inlet guide vane assembly comprising: Multiple guide vanes; a drive structure coupled to the plurality of guide vanes, wherein rotation of the drive structure transitions the plurality of guide vanes from a first position to a second position; Actuator; an actuation mechanism configured to transition the plurality of guide vanes between the first position and the second position based on operation of the actuator, wherein when the plurality of guide vanes are in the first position, the actuating mechanism applies a first amount of rotational force to drive the drive structure, and when the plurality of guide vanes are in the second position, the actuating mechanism applies a second amount of rotational force, and The actuation mechanism includes: a gear driven by the actuator; and a link arm having a first end and a second end, connected to the gear at a first point on the first end side, The drive structure includes a drive ring defining a first surface, The gear is arranged perpendicular to the first surface. The second point of the second end side of the link arm is connected to the drive ring, The gear moves the second point of the link arm by moving the first point of the link arm, thereby rotating the drive ring. An angle of an acute angle formed between a first line connecting the first end and the second end and the first surface varies according to an opening degree of the plurality of guide vanes.

2. An inlet guide vane assembly for a centrifugal compressor, the inlet guide vane assembly comprising: Multiple guide vanes; a drive structure coupled to the plurality of guide vanes, wherein rotation of the drive structure transitions the plurality of guide vanes from a first position to a second position; Actuator; an actuation mechanism configured to transition the plurality of guide vanes between the first position and the second position based on operation of the actuator, wherein when the plurality of guide vanes are in the first position, the actuating mechanism applies a first amount of rotational force to drive the drive structure, and when the plurality of guide vanes are in the second position, the actuating mechanism applies a second amount of rotational force, and The actuation mechanism includes: a gear driven by the actuator; and a link arm having a first end and a second end, connected to the gear at a first point on the first end side, The drive structure includes a drive ring defining a first surface, The gear is arranged perpendicular to the first surface. The second point of the second end side of the link arm is connected to the drive ring, The gear moves the second point of the link arm by moving the first point of the link arm, thereby rotating the drive ring. The rotation amount of the drive ring per unit rotation of the gear varies according to the opening degree of the plurality of guide vanes.

3. The inlet guide vane assembly according to claim 1 or claim 2, wherein: The actuating mechanism comprises a worm drive.

4. The inlet guide vane assembly according to claim 1 or 2, wherein: The gear is oval in shape.

Images