The subject matter disclosed herein relates to compressor devices and, in particular, to manipulation of flow parameters at an outlet region to expand the operating envelope of a compressor device (e.g., centrifugal compressors).
Compressor devices draw a working fluid into an inlet, compress the working fluid, and expel the compressed working fluid from an outlet. The flow parameters of the working fluid at the outlet are often set to satisfy performance and/or other characteristics for a process, application, and/or setting, that utilizes the compressor device. For example, the process may require the compressor to deliver the working fluid at a set of designated setpoints, e.g., flow rate, pressure, etc. The compressor device must operate in a manner so that the working fluid enters the inlet at an inlet flow rate to achieve these setpoints. However, as a competing interest, many process owners wish to operate the compressor device as efficiently as possible to reduce operating costs. Minimizing power consumption may require the compressor device to operate at the lower boundaries of the desired operating envelop, which defines the minimum compressor speed (e.g., speed of rotation for the impeller) and/or inlet flow rates to achieve the setpoints. In some implementations, operation of centrifugal compressors to achieve efficiencies can vary the compressor speed to match inlet flow and discharge pressure, maintain a fixed compressor speed and throttle the flow at the inlet (with one or more inlet guide vanes), and/or utilize a throttling valve at the discharge of the compressor. However, by approaching these lower boundaries of the operating envelop, the compressor device can enter various fault conditions (e.g., surge) that can have adverse affects on the process and, notably, damage the compressor device.
This disclosure describes improvements that can expand the operating envelope of a compressor device. These improvements implement devices that vary flow parameters of a working fluid at the exit of the compressor device. In one embodiment, the device utilizes a nozzle that installs into the discharge opening on a volute of a centrifugal compressor. Actuation of the nozzle modifies a flow area through which the working fluid exits the centrifugal compressor. The change in the flow area increases the velocity of the working fluid, without the need to change the operating speed and/or other operating parameters of the centrifugal compressor.
Reference is now made briefly to the accompanying drawings, in which:
Where applicable like reference characters designate identical or corresponding components and units throughout the several views, which are not to scale unless otherwise indicated.
At the outlet region 110, the nozzle device 100 has a nozzle outlet 118 that defines a nozzle outlet area 120. The compressor device 102 can couple with industrial piping at the outlet region 110. During operation, the working fluid flows through the nozzle outlet 118 into the industrial piping with flow parameters (e.g., pressure, velocity, flow rate, etc.) as desired. Values for the flow parameters are particular to the application and/or industry setting that implements the compressor device 102. Examples of these industries include automotive industries, electronic industries, aerospace industries, oil and gas industries, power generation industries, petrochemical industries, and the like.
The nozzle device 100 can modify the flow parameters of the working fluid that exits the flow housing 106. This feature effectively expands the operating envelope of the compressor device 102 to include, for example, flow rates at the inlet region 108 (also “inlet flow rates”) that would normally induce pressure pulsations indicative of surge. These pressure pulsations can disrupt operation and, often, stall the compressor device 102. To this end, use of the nozzle device 100 permits the compressor device 102 to continue to operate at inlet flow rates below inlet flow rates that would induce surge conditions. This configuration can also change the velocity of the working fluid that enters the industrial piping without the need to modify operating parameters (e.g., operating speed) of the compressor device 102.
As shown in
The control device 128 can communicate with a network system 148 with one or more external servers (e.g., external server 150) and a network 152 that connects the control device 128 to the external server 150. This disclosure also contemplates configurations in which one or more programs and/or executable instructions are found on the external server 150. The control device 128 can access these remotely stored items to perform one or more functions disclosed herein. In one embodiment, a computing device 154 may communicate with one or more of the control device 128 and the network 152, e.g., to interface and/or interact with the compressor device 100 and/or system 126, as desired.
At the system level, the control device 128 can instruct operation of the nozzle device 100 to change the size of the flow area. Use of the control device 128 and sensor element 146, for example, can create a feedback loop that monitors operation of the compressor device to select the appropriate flow area for the nozzle outlet 118. Examples of the sensor element 146 include devices that generate signals in response to a variety of fluid properties (e.g., pressure, temperature, relative humidity, etc.) in one or more locations, e.g., at locations in the flow housing 106 upstream of the outlet region 110 as well as throughout the compressor device 100. In one implementation, these signals contain data that reflects fluid pressure and, in particular, static fluid pressure in the flow housing 106. The control device 128 can utilize this data to generate an output with instructions that cause the nozzle device 100 to orient the nozzle outlet 118 to reflect the flow area that corresponds to the fluid pressure. For purposes of the present example, the feedback loop facilitates operation of the compressor device 102 by operating the nozzle device 100 to form the appropriate flow area to avoid surge based on the value for the static fluid pressure measured by the sensor element 146.
In other implementations, the system 126 can improve operation and/or efficiency of the flow housing and, in particular, the collector portion of a volute. The system 126 can utilize a plurality of sensor elements 146 to measure static pressure at points proximate the inlet to the volute and at points proximate the outlet, or discharge flange. The system 126 can also calculate total pressure, which comprises a static pressure and a dynamic pressure (e.g., pressure due to velocity of gas). In one example, the efficiency of the volute collector can be calculated according to Equations (1), (2), and (3) below,
wherein ηcollector is the volute collector efficiency, P1 is static pressure at a first point, P2 is static pressure at a second point that is downstream of the first point, PO1 is total pressure at the first point, and A2 and A1 are the projected area perpendicular to flow at, respectively, the first point and the second point. In one example, the first point and the second point are found, respectively, proximate the inlet of the volute and proximate the outlet of the volute.
As shown in
The step for receiving the first signal (e.g., at step 202) can utilize data that arises from a sensor (e.g., sensor 146 of
The step of selecting an outlet flow parameter (e.g., at step 204) relates, in one example, the value of the operating property to the velocity (and/or flow rate) of the working fluid at the outlet region (e.g., outlet region 110 of
The step for generating the output (e.g., at step 206) can activate the nozzle device to change the flow area of the nozzle outlet, e.g., between first flow area 122 of nozzle outlet 118 and second flow area 124 of nozzle outlet 118 of
The projections 370 can change position to modify the flow area of the nozzle outlet area 318. This feature can change the size of the nozzle outlet area 318, e.g., between the first nozzle area 122 and the second nozzle area 124 shown on
The area control element 378 can form an annular ring (and/or partially-annular ring) that circumscribes at least part of the elongated cylindrical element 362. This annular ring provides a rigid structure with a fixed inner diameter to secure the position of the roller elements 380. Examples of the roller elements 380 may include rollers, as shown, as well as castors, wheels, and like devices that facilitate motion. For example, in lieu of the roller elements 380, the actuator element 360 may include low-friction and/or bearing materials that can reduce friction, e.g., between the actuator element 360 and the guide elements 358.
In one implementation, the actuator element 360 can move along the longitudinal axis 358, e.g., between a first position and a second position. This movement causes the roller elements 380 to engage a different part (and/or point, section, portion) of the radially exterior edge 372 at the first position and the second position. As the roller elements 380 engage parts of the radially exterior edge 372 proximate the second end 376, the change in the radial distance of the radially exterior edge 372 will cause the roller elements 380 to apply force against the projections 370. This force will push the projections 370 inwardly, e.g., toward the longitudinal axis 318 to reduce the size of the nozzle outlet 318. On the other hand, engagement of the roller elements 380 with parts of the radially exterior edge 372 proximate the first end 374 will relieve the pushing force. In this position, the projections 370 will move outwardly, e.g., away from the longitudinal axis 368 to increase the size of the nozzle outlet 318. In one example, the nozzle device 300 may include one or more resilient members (e.g., a spring) that applies a bias force to one or more of the projections 370 to aid the movement of the projections 370 away from the longitudinal axis 368.
Construction of the components (e.g., the elongated cylindrical element 362, the guide elements 358, and the area control element 378) can utilize a wide variety of materials (e.g., metals, plastics, composites, etc.). These components may be constructed as unitary components which are fastened together to form the nozzle device 300, e.g., using screws, bolts, welds, and the like. In other constructions, the components (e.g., the projections 370 and the guide elements 358 are formed monolithically as an integrated structure. However, aspects of the implementation of the nozzle device 300 may dictate construction and materials with properties (e.g., corrosion resistance) or exhibit certain characteristics that are more appropriate, e.g., for certain types of working fluid, flow parameters, and other conditions.
In light of the foregoing discussion, movement of the actuator element 360 between the first position (
Compressor devices that utilize electric motors as the prime mover of the impeller can also benefit from implementation of the proposed designs. Use of the variable volute can reduce current in-rush that can occur, for example, during start-up of a compressor device. In one implementation, compressor devices that are not able to operate at lower inlet volume flows must be shut down while another compressor device is brought on-line. Current in-rush can occur when the shut-down compressor device is activated and brought back on-line.
As set forth herein, embodiments of the various control and processing devices (e.g., control device 128 of
These control devices may have constructive components that can communicate amongst themselves and/or with other circuits (and/or devices), which execute high-level logic functions, algorithms, as well as executable instructions (e.g., firmware instructions, software instructions, software programs, etc.). Exemplary circuits of this type include discrete elements such as resistors, transistors, diodes, switches, and capacitors. Examples of a processor (e.g., processor 130 of
The structure of these control devices can permit certain determinations as to selected configuration and desired operating characteristics that an end user might convey via the graphical user interface or that are retrieved or need to be retrieved by the device. For example, the electrical circuits of these control devices can physically manifest theoretical analysis and logical operations and/or can replicate in physical form an algorithm, a comparative analysis, and/or a decisional logic tree, each of which operates to assign the output and/or a value to the output that correctly reflects one or more of the nature, content, and origin of the changes in parameters (e.g., flow parameters of a working fluid) that are reflected by the inputs to these control devices as provided by the corresponding control circuitry, e.g., control circuitry 132 of
In one embodiment, a processor (e.g., processor 130 of
However, although processor, memory, and the components of control circuitry might include discrete circuitry and combinations of discrete components, this need not be the case. For example, one or more of these components can comprise a single integrated circuit (IC) or other component. As another example, a processor can include internal program memory such as RAM and/or ROM. Similarly, any one or more of functions of these components can be distributed across additional components (e.g., multiple processors or other components).
Moreover, as will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.
Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. Examples of a computer readable storage medium include an electronic, magnetic, electromagnetic, and/or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
A non-transitory computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms and any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.
Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language and conventional procedural programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.
The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
Accordingly, a technical effect of embodiments of the systems and methods proposed herein is to identify operating settings for a compressor device (e.g., pressures, flow rates, etc.) to achieve one or more setpoints, and/or, in one example, to operate the compressor device at the operating settings, and/or, in one example, to arrange a nozzle device with an appropriate flow area to reduce power consumption of the compressor device.
As used herein, an element or function recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural said elements or functions, unless such exclusion is explicitly recited. Furthermore, references to “one embodiment” of the claimed invention should not be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.