SYSTEM AND METHOD FOR OPERATING A COMPRESSOR DEVICE
Embodiments of a system and method manipulate the position of inlet guide vanes and the drive speed for optimizing performance of a compressor device (e.g., a centrifugal compressor). In one embodiment, the systems and methods can correlate setpoints (e.g., inlet volume flow and discharge pressure) desired for installation and/or implementation of the compressor device with reference data collected as part of in-situ performance testing. This reference data identifies, in one embodiment, a position for the inlet guide vanes and a drive speed for a number of different setpoints at a set of reference conditions (e.g., ambient temperature and ambient pressure).
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The subject matter disclosed herein relates to compressor devices (e.g., centrifugal compressors) and, in particular, to systems and methods for optimizing performance of a compressor device comprising an inlet guide vane assembly and a variable speed drive.
Many compressor devices (e.g., centrifugal compressors) use inlet guide vanes to modulate flow of working fluid into the compressor device. For example, the position of the inlet guide vanes can vary to increase and decrease the flow rate, e.g., by changing the effective flow area at the inlet to the compressor. When used in combination with variable speed drives, which can change the rotation speed of the impeller, conventional control systems can manipulate the operation of the compressor device to improve performance, efficiency, and, moreover, reduce cost of operation by reducing power consumption.
The process to optimize performance of these compressor devices often requires extensive testing and qualification. This process can be labor and time intensive and, moreover, must often be performed on individual compressor devices at localized installations.
BRIEF DESCRIPTION OF THE INVENTIONThis disclosure describes improvements that reduce the time and effort necessary to qualify compressor devices with variable inlet guide vanes and variable speed drives for use in the field. These improvements correlate setpoints (e.g., inlet flow volume and discharge pressure) desired for a specific installation and/or implementation of the compressor device with reference data collected as part of in-situ performance testing. This reference data identifies, in one embodiment, a position for the inlet guide vanes and a drive speed for a number of different setpoints at a set of reference conditions. As set forth below, this disclosure proposes embodiments of systems and methods that use this reference data to select operation settings necessary to achieve the desired setpoints at the current conditions (which are different from the reference conditions) as well as to enhance overall performance of the compressor device.
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.
DETAILED DESCRIPTION OF THE INVENTIONBroadly, the discussion below focuses on embodiments of systems and methods that modify performance of a compressor device (e.g., centrifugal compressors). These embodiments can identify operation settings (e.g., positions for inlet guide vanes and drive speed) on the compressor device to achieve certain desired setpoints (e.g., inlet flow volume and discharge pressure) without the need to perform extensive testing to qualify the performance of the compressor device. In one aspect, the systems and methods select operation settings by correlating the desired setpoints with a set of baseline performance measurements. This set of data quantifies operation of the compressor device at certain operating conditions (e.g., ambient temperature, ambient pressure, relative humidity, etc.).
The systems and methods further utilize data about operation of the compressor device to configure the compressor device, e.g., to select a position for inlet guide vanes in an inlet guide vane assembly that resides upstream of an impeller and/or to select a drive speed for the impeller. Moreover, by continually monitoring operating parameters (e.g., discharge pressure) and making adjustments to the position of the inlet guide vanes and/or the drive speed, the embodiments below form a feedback loop that can improve compressor efficiency as well as increase the performance envelope. For example, the systems and methods can set the position of the inlet guide vanes and the speed of the impeller to maintain the working fluid at one or more desired flow parameters (e.g., inlet flow rate and discharge pressure) while operating at the lowest possible power input to the drive unit.
As best shown in the configuration of
Examples of the controller 436 include computers and computing devices with processors and memory that can store and execute certain executable instructions, software programs, and the like. The controller 436 can be a separate unit, e.g., part of a control unit that operates the compressor device 400 and other equipment. This control unit and/or the controller 436 can be located remote from the compressor device 400, with communication between the compressor device 400 and the controller 436 occurring by way of wireless and wired communication, e.g., via network 444. In other examples, the controller 436 integrates with the compressor device 400, e.g., as part of the hardware and/or software that operates the drive unit 410 and/or the actuator 428.
Examples of the operating condition sensor 438 provide information about the environment surrounding the compressor device 400. This information can include ambient temperature, ambient pressure, and relative humidity, among other measurements. As set forth below, implementations of the system 434 can use this information to determine operation settings (e.g., positions for the inlet vane guides 416 and speed of the drive unit 410) for desired setpoints using these operating conditions and, in one particular example, correlating the setpoints for operating conditions during current operation with operating conditions that prevail during in-situ testing of the compressor device.
The parameter sensor 440 monitors one or more operating parameters of the compressor device 400. Examples of these operating parameters include flow parameters (e.g., flow rate, flow velocity, static pressure, head pressure, etc.) and mechanical parameters (e.g., input power, current, voltage, torque, etc.), among others. The parameter sensor 440 can comprise one or more sensor devices that are sensitive to the operating parameters. These sensor devices can embody flow meters, pressure transducers, accelerometers, and like components. Such devices generate signals (e.g., analog and digital signals), which encode a measured value for the corresponding operating parameter that the device is configured to measure.
Examples of the parameter sensor 440 may couple with a shaft or other mechanism that transfers energy from the drive unit 410 to the impeller 412. When in this position, the parameter sensor 440 can measure several parameters (e.g., torque, angular velocity, etc.) that define the operation of the drive unit 410 and/or the compressor device 400 in general. Other positions for the parameter sensor 440 include proximate the interior of the volute (e.g., volute 106 of
Embodiments of the system 434 can include a plurality of sensor devices (e.g., parameter sensor 440) that measure different operating parameters. For example, the system 434 may deploy a flow meter at the inlet (e.g., inlet 102 of
In one embodiment, movement of the actuator 428 changes the orientation of the inlet guide vane 418 with respect to the flow of the working fluid. While this disclosure contemplates a wide range of configurations for the inlet guide vane 418, in one example the inlet guide vane 418 can rotate from one position (e.g., the first position) to another position (e.g., the second position), and vice versa. When found in an inlet guide vane assembly (e.g, inlet guide vane assembly 216 of
As mentioned above, the first set of operating conditions (e.g., at step 502) can describe conditions (e.g., temperature, pressure, relative humidity, etc.) in which the compressor device operates. These conditions can influence the position of the inlet guide vanes and the speed of the drive unit to obtain the desired setpoint. Data and information about the first set and the second set can arise from one or more sensing devices (e.g., operating condition sensors 438 of
The steps for converting a first setpoint to a second setpoint (e.g., at step 504) can associate operation settings for the compressor device to achieve the desired setpoint with operation settings for the compressor device that are used under different operating conditions. As set forth above, operation settings for the compressor device can include the position and/or orientation of the inlet guide vanes and the drive speed of the drive unit and/or combinations thereof. These steps can determine an appropriate operation setting for the compressor device to achieve the desired setpoint. In one embodiment, the method 500 can include one or more steps for collecting operation data via in-situ testing of the compressor device. Such testing can quantify a baseline compressor performance, e.g., in connection with certain operation settings for the compressor device. In one example, the second set of operating conditions define the operating conditions (e.g., temperature, pressure, relative humidity, etc.) that prevail at the time the in-situ testing occurred.
Embodiments of the method 500 can include steps for converting a first inlet volume flow to a second inlet volume flow, wherein the second inlet volume flow represents the inlet volume flow at the reference (or second set) of operating conditions. In one example, the inlet volume flow is calculated according to equation (1) below:
wherein SPsecond is the second setpont at the second set of operating conditions (e.g., ambient temperature and ambient pressure during in-situ performance testing), SPfirst is the first setpoint at the first set of operating conditions (e.g., day-to-day ambient temperature and ambient pressure), Pfirst is the ambient pressure for the first set of operating conditions, Psecond is the ambient pressure for the second set of operating conditions, Tfirst is the ambient temperature for the first set of operating conditions, and Tsecond is the ambient temperature for the second set of operating conditions.
The method 500 can also include steps for converting a first discharge pressure to a second discharge pressure. In one embodiment, the second discharge pressure represents the discharge pressure at the reference (or second set) of operating conditions relative to surge (and/or surge conditions). Surge conditions are a characteristic of compressor devices, which define the minimum flow at which the compressor device can impart energy to the working fluid to overcome system resistance. Examples of surge conditions are influenced by the configuration of the system (e.g., piping, system back pressure, etc.). At the onset of surge conditions, the inlet volume flow becomes unstable, which can result in flow reversal fluctuations during which flow fluctuates between suction and discharge.
The method 500 can use the surge condition characteristics for calculating a value for adiabatic head pressure and for selecting a value for the second discharge pressure that corresponds with the value for adiabatic head pressure. Adiabatic head pressure can link discharge pressure at the surge conditions to discharge pressure required at the current conditions. In one example, the step of converting correlates adiabatic head pressure for the compressor device at the current conditions with adiabatic head pressure at the reference conditions to select the second discharge pressure. In one particular example, the method 500 includes steps to calculate the adiabatic head pressure according to equation (2) below,
wherein Headadiabatic is the adiabatic head pressure at the current conditions, k is heat capacity ratio for the working fluid, Za is the average gas compressibility factor for the working fluid, R is the gas constant for the working fluid, MW the molecular weight for the working fluid, T1 is the ambient temperatures for the current operating conditions, P1 is the ambient pressure for the current conditions, and P2 is the discharge pressure at surge for the current conditions. Using the equation 2 above, the method 500 correlates the value for Headadiabatic at the current conditions with the value for Headadiabatic calculated at the reference conditions during in-situ performance testing to identify the second discharge pressure.
Embodiments of the method 500 can also identify situations in which the setpoints may place the compressor device into a fail condition. Exemplary fail conditions include the surge conditions above that cause the flow to fluctuate between suction and discharge. The method 500 can include one or more steps for generating an alert in response to values for the setpoint that can cause the compressor device to enter the fail condition. In one example, these steps can include steps for comparing the inlet flow volume at the required discharge pressure against values found on a control surge line. Examples of the control surge line define combinations of setpoints that will cause surge to occur. If the inlet flow volume meets or exceeds the value on the control surge line, then the method 500 can include steps for generating an output that conveys information of the pending and/or possible fail condition.
The steps for selecting an operation setting (e.g., at step 506) can utilize a look-up table and/or other repository that reflects data gathered at the reference (or second set) of operating conditions. Table 1 below is one example of a look-up table for this purpose
As set forth above, Table 1 compiles data collected from in-situ performance testing at the second set (or reference) operation conditions. In one example, the data reflects the discharge pressure and inlet flow volume for the compressor device configured in a given set of operation settings (e.g., the position (%) of the IGV and the drive speed (Hz)). This data is collected at certain operating conditions (e.g., ambient temperature and ambient pressure), which help correlate the desired setpoints with the data in Table 1 (as discussed above).
Embodiments of the method 500 can also include steps for locating the second setpoint (i.e., the converted first (or current) setpoint) in Table 1 and steps for assigning values for the operation settings that correspond to the second setpoint identified in Table 1. For example, if the second setpoint comprises an inlet volume flow with a value of 29,000 SCFM, then the method 500 would assign values for the operation setting found in Table 1 that comprise a value of 35 for % IGV and 52 Hz. These values correspond to, respectively, the position of the inlet guide vanes and the frequency for the variable speed drive for the compressor device to achieve the inlet flow value of 29,000 SCFM.
In one embodiment, the method 500 can include steps for interpolating and/or manipulating data in Table 1, e.g., if the second setpoint is not found in Table 1. These steps can include, for example, selecting a first value and a second value for the operation setting that correspond to, respectively, an upper value (“UV”) for the second setpoint and a lower value (“LV”) for the second setpoint. The steps can also include, for example, calculating a required value (“RV”) for the operation setting, wherein the required value can be calculated according to equation (3) below:
wherein OPrv is the required operation setting (e.g., IGV setting and/or drive speed), ° Plv is the lower value for the operating setting (e.g., IGV setting and/or drive speed), OPuv is the upper value of the operating setting (e.g., IGV setting and/or drive speed), SPrv is the value for the second setpoint (e.g., inlet volume flow and/or or discharge pressure), SPlv is the lower value for the second setpoint (e.g., inlet volume flow and/or or discharge pressure), and SPuv is the upper value for the second setpoint (e.g., inlet volume flow and/or or discharge pressure).
This disclosure contemplates use of the Table 1, and the various steps for locating, assigning, and interpolating for use with various input setpoints comprising inlet volume flows (as used in the implementation example above) and discharge pressures. For purposes of the latter, i.e., if the setpoint is discharge pressure, the implementation will focus use of the Table 1 to identify the particular value of the discharge pressure. Likewise, any interpolation can occur by way of equation (3), using values for the various variables that correspond to discharge pressure. Moreover, in other embodiments, the method 500 may include steps for identification of operation settings for the compressor device based on a plurality of setpoints including inlet volume flow and discharge pressure, wherein one or more both of the values for inlet volume flow and discharge pressure would require interpolation and/or use of equation (3) above to assign values to the operation settings.
The steps for generating an output (e.g., at step 508) can instruct the components of the compressor device to operate according to the values of the operation settings. Thus, the output can set the inlet guide vanes and/or the drive unit to, respectively, the position and speed that is assigned in the steps described above. In other examples, the output may provide a visual indication to an end user of the operation settings, e.g., on a display and/or as an alpha-numeric indication from which the end user can understand the appropriate operation setting based on the desired setpoints. The end user can manually adjust the components of the compressor device to achieve the operation settings. However, this disclosure contemplates the various ways in which the operation of the compressor device can be made to operate in accordance with the operation settings.
To illustrate, an example of a method 700 for operating a compressor device to improve efficiency is shown in
The step of receiving a first signal (e.g., at step 702) and a second signal (e.g., a step 704) occur at different operation settings. The operation settings define one or more settings, or combinations of settings, for the components (e.g., inlet guide vanes, drive unit, variable speed unit, etc.). In one example, the settings of the first operation settings are different from the settings of the second operation settings in order to capture potential changes in operation of the compressor device. To illustrate,
Communication of the first signal and the second signal can occur by way of wireless and/or wired communication, e.g., between the parameter sensor 440 (
The step for comparing the first value and the second value (e.g., a step 706) identifies the change or variation in operation of the compressor device 100 (
The step of selecting an increment (e.g., at step 708) provides an incremental change in the operation setting. This incremental change is meant to change operation of the compressor device, e.g., to improve performance of the compressor device. Examples of the incremental change can define both the amount of movement that will occur in the inlet guide vane 800 as well as the direction of movement. In other examples, the incremental change can cause a variation in the drive speed of the drive unit. This variation can, for example, prescribe a change in the frequency (Hz) of a variable frequency drive.
The amount of the angular offset can vary, both between the first angular offset and the second angular offset as well as based on the first value and the second value for the operating parameter. For example, embodiments of the method 700 may include steps for calculating a variation value, which can have a value equal to the mathematical different between the first value and the second value, and a step for comparing the variation value to a threshold criteria that can define the nominal values for the positional characteristics. In one example, if the variation value satisfies the threshold criteria, then the method 700 may include steps for assigning values to the increment 860. These values may decrease as the variation value decreases, e.g., as the operation of the compressor device converges to an optimal set of operation characteristics.
The step of generating an output (e.g., at step 710) can cause the compressor device to operate according to different operation settings. In one example, the output encodes instructions that cause the inlet guide vane 800 to move, as between the second position 852 and the third position 858. The output can comprise any signal (e.g., analog and/or digital) that can encode instructs to operate a device. In the examples herein, the output can cause an actuator (e.g., actuator 228, 328, 428 of
In view of the foregoing discussion of the methods 500, 600, and 700, collectively, one or more of the steps of the methods 500, 600, and 700 can be coded as one or more executable instructions (e.g., hardware, firmware, software, software programs, etc.). These executable instructions can be part of a computer-implemented method and/or program, which can be executed by a processor and/or processing device. Examples of the controller 436 (
This disclosure further contemplates embodiments in which any one of the methods 500, 600, and 700 embodies an iterative and/or multi-operational technique to focus and optimize operation, e.g., of the compressor device 100, 200, 300, 400 (
In one embodiment, the controller 900 includes a processor 902, memory 904, and control circuitry 906. Busses 908 couple the components of the controller 900 together to permit the exchange of signals, data, and information from one component of the controller 900 to another. In one example, the control circuitry 906 includes sensor driver circuitry 910 which couples with an operating condition sensor 912 (e.g., operating condition sensor 438 of
This configuration of components can dictate operation of the controller 900 to analyze data, e.g., information encoded by the signals from the operating condition sensor 912, parameter sensor 914, variable speed drive 918, and/or drive unit 920, to identify appropriate orientation of the inlet guide vanes and/or operating speed of the drive unit 920 of the compressor device. For example, the controller 900 can provide signals (or inputs or outputs) to speed up and slow down the drive unit 920, change the inlet guide vanes from the first position to the second position, and/or actuate other devices that change the operation of the compressor device.
The controller 900 and its constructive components 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 the processor 902 include microprocessors and other logic devices such as field programmable gate arrays (“FPGAs”) and application specific integrated circuits (“ASICs”). Although all of the discrete elements, circuits, and devices function individually in a manner that is generally understood by those artisans that have ordinary skill in the electrical arts, it is their combination and integration into functional electrical groups and circuits that generally provide for the concepts that are disclosed and described herein.
The structure of the components in the controller 900 can permit certain determinations as to selected configuration and desired operating characteristics that an end user convey via the graphical user interface or that are retrieved or need to be retrieved by the device. For example, the electrical circuits of the controller 900 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 that occur and that are reflected by the inputs to the controller 900 as provided by the corresponding control circuitry, e.g., in the control circuitry 906.
In one embodiment, the processor 902 is a central processing unit (CPU) such as an ASIC and/or an FPGA that is configured to instruct and/or control operation one or more devices. This processor can also include state machine circuitry or other suitable components capable of controlling operation of the components as described herein. The memory 904 includes volatile and non-volatile memory and can store executable instructions in the form of and/or including software (or firmware) instructions and configuration settings. Each of the control circuitry 906 can embody stand-alone devices such as solid-state devices. Examples of these devices can mount to substrates such as printed-circuit boards and semiconductors, which can accommodate various components including the processor 902, the memory 904, and other related circuitry to facilitate operation of the controller 900.
However, although
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 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 the compressor device, e.g., the position of the inlet guide vanes and the drive speed, 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 position the inlet guide vanes and the drive speed 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.
Claims
1. A system, comprising:
- a compressor device comprising an impeller, a drive unit coupled with the impeller, and an inlet guide vane in flow connection with the impeller;
- a controller coupled with the compressor device, the controller comprising a processor, memory, and executable instructions stored on memory and configured to be executed by the processor, the executable instructions comprising instructions for: receiving a first signal encoding a first set of operating conditions for the compressor device; converting a first setpoint to a second setpoint for the compressor device, the second setpoint corresponding to a second set of operating conditions that is different from the first set of operating conditions; selecting an operation setting for the compressor device to achieve the second setpoint; and generating an output encoding instructions to operate the compressor device according to the operation setting.
2. The system of claim 1, wherein the second setpoint identifies a value for an inlet volume flow for working fluid upstream of the impeller.
3. The system of claim 1, wherein the second setpoint identifies a discharge pressure for working fluid proximate an outlet of the compressor device.
4. The system of claim 1, wherein the operation setting identifies a position for the inlet guide vanes.
5. The system of claim 1, wherein the operation setting identifies a drive speed for the drive unit.
6. The system of claim 1, wherein the first set of operating conditions and the second set of operating conditions comprise values for an ambient temperature and an ambient pressure during operation of the compressor device.
7. The system of claim 6, wherein the second setpoint is calculated according to: SP second = SP first ( P second P first ) × ( T first T second ),
- wherein SPsecond is the second setpont at the second set of operating conditions, SPfirst is the first setpoint at the first set of operating conditions, Pfirst is the ambient pressure for the first set of operating conditions, Psecond is the ambient pressure for the second set of operating conditions, Tfirst is the ambient temperature for the first set of operating conditions, and Tsecond is the ambient temperature for the second set of operating conditions.
8. The system of claim 6, wherein the executable instructions include instructions for: Head adiabatic = ( K K - 1 ) ( Z a RT 1 MW ) [ ( P 2 P 1 ) ( k - 1 k ) - 1 ],
- calculating a value for adiabatic head pressure at the first set of operating conditions, and
- selecting a value for the second setpoint that corresponds with the value for adiabatic head pressure at the second set of operating conditions,
- wherein the value for adiabatic head pressure is calculated according to:
- wherein Headadiabatic is the adiabatic head pressure for an ambient temperature and an ambient pressure at the first set of operating conditions, k is heat capacity ratio for the working fluid, Za is the average gas compressibility factor for the working fluid, R is the gas constant for the working fluid, MW the molecular weight for the working fluid, T1 is the ambient temperature at the first set of operating conditions, P1 is the ambient pressure at the first set of operating conditions, and P2 is the discharge pressure at surge.
9. The system of claim 1, further comprising instructions for:
- comparing the second setpoint to a threshold value corresponding to a fail condition for the compressor device; and
- adjusting operation of the compressor device according to the operation setting if the second setpoint meets or is less than the threshold value.
10. The system of claim 9, wherein the threshold value defines a minimum inlet volume flow for prevent compressor surge.
11. The system of claim 1, further comprising instructions for: OP rv = OP lv + ( OP uv - OP lv ) ( SP rv - SP lv ) ( SP uv - SP lv ),
- selecting a first value and a second value for the operation setting that correspond to, respectively, an upper value for the second setpoint and a lower value for the second setpoint; and
- calculating a required value for the operation setting, wherein the required value is calculated according to:
- wherein OPrv is the required value for the operation setting, OPlv is the first value for the operating setting, OPuv is the second value of the operating setting, SPrv is the value for the second setpoint, SPlv is the lower value for the second setpoint, and SPuv is the upper value for the second setpoint.
12. The system of claim 11, wherein the second setpoint comprises discharge pressure for working fluid from the compressor device.
13. The system of claim 11, further comprising a variable frequency drive coupled with the drive unit, the variable frequency drive generating a motor input that defines a motor input frequency and a motor input voltage, wherein the instructions define one or more of the motor input frequency and the input voltage.
14. A compressor device, comprising:
- a controller comprising a processor, memory, and executable instructions stored on memory and configured to be executed by the processor, the executable instructions comprising instructions for: receiving a signal encoding a first set of operating conditions for the compressor device; converting a first setpoint to a second setpoint for the compressor device, the second setpoint corresponding to a second set of operating conditions that is different from the first set of operating conditions; selecting an operation setting for the compressor device to achieve the second setpoint; and generating an output encoding instructions to operate the compressor device according to the operation setting.
15. A controller for operating a compressor device, said controller comprising:
- a processor;
- memory; and
- executable instructions stored on memory and configured to be executed by the processor, the executable instructions for: receiving a first signal encoding a first set of operating conditions for the compressor device; converting a first setpoint to a second setpoint for the compressor device, the second setpoint corresponding to a second set of operating conditions that is different from the first set of operating conditions; selecting a first operation setting for the compressor device to achieve the second setpoint; and generating an output encoding instructions to operate the compressor device according to the first operation setting.
16. The controller of claim 15, further comprising executable instructions for: OP rv = OP lv + ( OP uv - OP lv ) ( SP rv - SP lv ) ( SP uv - SP lv ),
- selecting a first value and an second value for the operation setting that correspond to, respectively, an upper value for the second setpoint and a lower value for the second setpoint; and
- calculating a required value for the operation setting, wherein the required value is calculated according to:
- wherein OPrv is the required value for the operation setting, OPlv, is the first value for the operating setting, OPuv is the second value of the operating setting, SPrv is the value for the second setpoint, SPlv is the lower value for the second setpoint, and SPuv is the upper value for the second setpoint.
17. The controller of claim 15, further comprising instructions for: SP second = SP first ( P second P first ) × ( T first T second ),
- calculating the second setpoint according to:
- wherein SPfirst is the first setpoint, SPsecond is the second setpoint, Pfirst is ambient pressure for the first set of operating conditions, Psecond is ambient pressure for the second set of operating conditions, Tfirst is ambient temperature for the first set of operating conditions, and Tsecond is ambient temperature for the second set of operating conditions.
18. The controller of claim 15, further comprising instructions for: Head adiabatic = ( K K - 1 ) ( Z a RT 1 MW ) [ ( P 2 P 1 ) ( k - 1 k ) - 1 ],
- calculating a value for adiabatic head pressure, and
- selecting a value for the second setpoint that corresponds with the value for adiabatic head pressure,
- wherein the value for adiabatic head pressure is calculated according to:
- wherein Headadiabatic is the adiabatic head pressure for an ambient temperature and an ambient pressure during operation of the compressor device, k is heat capacity ratio for the working fluid, Za is the average gas compressibility factor for the working fluid, R is the gas constant for the working fluid, MW the molecular weight for the working fluid, T1 is the ambient temperature, P1 is the ambient pressure, and P2 is the discharge pressure at surge.
19. The controller of claim 15, further comprising instructions for:
- receiving a second signal encoding a first value for an operating parameter for the compressor device operating according to a first position for an inlet guide vane;
- receiving a third signal encoding a second value for the operating parameter for the compressor device operating according to a second position for an inlet guide vane;
- comparing the first value and the second value;
- selecting an increment by which to change the second position, the increment defining the relative position of the second value with respect to the first value; and
- generating an output encoding instructions to move the inlet guide vane from the second position by the increment.
20. The controller of claim 19, wherein the operating parameter comprises an input power value for the drive unit.
21. The controller of claim 15, further comprising instructions for:
- receiving a second signal encoding a first value for an operating parameter for the compressor device operating according to a first setting of a variable speed drive;
- receiving a third signal encoding a second value for the operating parameter for the compressor device operating according to a second setting for the variable speed drive;
- comparing the first value and the second value;
- selecting an increment by which to change the second operation setting, the increment defining the relative position of the second value with respect to the first value; and
- generating an output encoding instructions to move the second setting by the increment.
22. The controller of claim 21, wherein the operating parameter comprises an input power value for the drive unit.
23. The controller of claim 21, wherein the operating parameter comprises a power transmission value that measures torque applied to the impeller by the drive unit.
24. A computer program product for improving efficiency of a compressor device, the computer program product comprising a computer readable storage medium having executable instructions embodied therein, wherein the executable instructions comprise one or more executable instructions for:
- receiving a signal encoding a first set of operating conditions for the compressor device;
- converting a first setpoint to a second setpoint for the compressor device, the second setpoint corresponding to a second set of operating conditions that is different from the first set of operating conditions;
- selecting an operation setting for the compressor device to achieve the second setpoint; and
- generating an output encoding instructions to operate the compressor device according to the operation setting.
Type: Application
Filed: Aug 31, 2012
Publication Date: Mar 6, 2014
Applicant: Dresser, Inc. (Addison, TX)
Inventors: Dale Eugene Husted (Centerville, IN), Timothy Daniel Hilgart (Cedarburg, WI)
Application Number: 13/601,862
International Classification: F01D 17/02 (20060101);