The present disclosure relates to gas turbine engine starter systems and associated methods.
During standard, steady-state operating conditions, a gas turbine engine operates to produce an engine torque via a continuous and self-sustaining combustion process. The combustion process generates combustion gases that drive a turbine, which in turn drives a compressor via an engine shaft to provide an airflow that fuels to the combustion process. However, in order to initiate self-sustaining operation of a gas turbine engine, an external power source is necessary to initiate rotation of the turbine, the compressor, and/or the engine shaft until the combustion process becomes self-sustaining. In many examples, this external power source is provided in the form of an engine starter that includes an electric motor that accelerates the gas turbine engine components from rest. However, various conventional engine starters are not configured for regulation of the electric motor other than by commanding the electric motor to an “on” or an “off” state. As a result, the resulting acceleration of the components of the gas turbine engine may be uncontrolled, and/or may proceed at a rate that is not optimally conducive to initiating self-sustaining operation of the gas turbine engine. Thus, there exists a need for improved gas turbine engine starter systems and associated methods.
Gas turbine engine starter systems and associated methods are disclosed herein. A gas turbine engine starter system for initiating operation of a gas turbine engine during an engine startup process includes an engine starter. The engine starter is configured to generate a starter torque during the engine startup process to initiate operation of the gas turbine engine to produce an engine torque. The engine starter includes a starter torque output that is configured to rotate at a starter rotational speed and to convey the starter torque to the gas turbine engine during the engine startup process to initiate operation of the gas turbine engine. The gas turbine engine is characterized by an engine starting speed envelope that encompasses a range of engine starting rotational speeds corresponding to initiation of a combustion process within the gas turbine engine during the engine startup process. The engine startup process includes a spool-up time interval in which the engine rotational speed increases from a non-operative engine rotational speed to a speed within the engine starting speed envelope. The gas turbine engine starter system is configured such that, during operative use of the gas turbine engine starter system and during at least a portion of the spool-up time interval, the starter torque is less than a speed-dependent maximum torque value of the starter torque that the engine starter is configured to produce.
A method of operating a gas turbine engine starter system to initiate operation of a gas turbine engine during an engine startup process includes utilizing an engine starter of the gas turbine engine starter system. Specifically, the engine starter is configured to generate a starter torque during the engine startup process to initiate operation of the gas turbine engine. The gas turbine engine starter system additionally includes an engine controller programmed to generate and transmit a starter control signal to the engine starter. The method of operating the gas turbine engine starter system includes regulating the operation of the engine starter with the engine controller. Specifically, the regulating the operation of the engine starter includes accelerating the gas turbine engine to bring an engine rotational speed of the gas turbine engine to within an engine starting speed envelope that encompasses a range of engine starting rotational speeds corresponding to initiation of a combustion process within the gas turbine engine during the engine startup process. The accelerating the gas turbine engine includes operating the engine starter such that the starter torque is less than a speed-dependent maximum torque value of the starter torque that the engine starter is configured to produce during at least a portion of a spool-up time interval of the engine startup process. Specifically, during the spool-up time interval, the engine rotational speed increases from a non-operative engine rotational speed to a speed within the engine starting speed envelope.
Generally, in the Figures, elements that are likely to be included in a given example are illustrated in solid lines, while elements that are optional to a given example are illustrated in dashed lines. However, elements that are illustrated in solid lines are not essential to all examples of the present disclosure, and an element shown in solid lines may be omitted from a given example without departing from the scope of the present disclosure. Additionally, in some Figures, one or more components and/or portions thereof that are obscured from view also may be illustrated in dashed lines.
As described in more detail herein, the present disclosure relates generally to a gas turbine engine starter system 100 with an engine starter 200 for initiating operation of a gas turbine engine 110 during an engine startup process. In particular, and as described in more detail herein, operation of gas turbine engine 110 may be described in terms of an engine rotational speed thereof, and gas turbine engine starter system 100 is configured to utilize engine starter 200 to increase the engine rotational speed during the engine startup process of gas turbine engine 110.
As used herein, the term “engine startup process” refers to a series of events, and/or to one or more time intervals in which the events take place, during which gas turbine engine 110 transitions from an inactive and/or initial state, in which the engine rotational speed is a non-operative engine rotational speed, to an operational state, in which gas turbine engine 110 operates independent of engine starter 200 and in which the engine rotational speed is greater than the non-operative engine rotational speed. Accordingly, the engine startup process encompasses a period of time in which gas turbine engine starter system 100 is in operative use to initiate operation of gas turbine engine 110, as described herein. In some examples, the non-operative engine rotational speed represents an engine rotational speed of zero. However, this is not required, and it additionally is within the scope of the present disclosure that the non-operative engine speed characterizing the beginning of the engine startup process may be nonzero, such as an engine rotational speed that is negligible, that is close to zero, and/or that otherwise is insufficient for continuous operation of gas turbine engine 110. In some examples, and as described herein, the engine startup process encompasses a period of time that extends beyond the period of time in which gas turbine engine starter system 100 is in operative use to initiate operation of gas turbine engine 110.
As used herein, the term “operative use,” as used to describe a state and/or condition of gas turbine engine starter system 100, is intended to refer to any state and/or condition in which gas turbine engine starter system 100 and/or engine starter 200 is actively utilized to increase the engine rotational speed as described herein. Accordingly, descriptions herein of gas turbine engine starter system 100 and/or of engine starter 200 as being operatively utilized, and/or as being in operative use, are to be understood as referring to circumstances, processes, and/or instances that take place within the engine startup process.
Gas turbine engine starter system 100 is configured to be utilized in conjunction with examples of gas turbine engine 110 in which a self-sustaining combustion process operates to generate an engine torque. In some examples, gas turbine engine starter system 100 may be described as including gas turbine engine 110. In other examples, gas turbine engine starter system 100 may be described as being a system that is distinct from gas turbine engine 110 and that is utilized in conjunction with gas turbine engine 110. Examples of gas turbine engine starter systems 100 and of gas turbine engines 110 are schematically illustrated in
As schematically illustrated in
Gas turbine engine 110 may be a component of, and/or may be operatively utilized in conjunction with, any of a variety of systems, such as may be associated with vehicle 10. For example, and as schematically illustrated in
In some other examples, and as schematically illustrated in
In many cases, in order to transition gas turbine engine 110 from an initially inactive state to a state of self-sustaining operation, it is necessary to initiate rotation of engine shaft 120 and/or of powerhead compressor 140, such as with an externally applied torque. Accordingly, and as schematically illustrated in
In many cases, in order to initiate self-sustaining operation of gas turbine engine 110, it is necessary to utilize engine starter 200 to accelerate the engine rotational speed to a speed at which powerhead compressor 140 drives engine airflow 132 to combustion chamber 150 at a sufficient flow rate to stably support the combustion process within combustion chamber 150. Such an engine rotational speed may be a characteristic of gas turbine engine 110, and/or may be at least partially based upon various environmental factors affecting gas turbine engine 110. To illustrate this,
For a particular instance and/or circumstance in which gas turbine engine 110 transitions from the inactive state to a state of stable and/or self-sustaining operation, engine starting rotational speed 332 corresponds to an engine rotational speed that is conducive to initiation of stable and/or self-sustaining combustion of air-fuel mixture 134 within combustion chamber 150, which may depend upon any of a variety of variable factors. In particular, in some examples, engine starting rotational speed 332 is at least partially based upon an operational condition of gas turbine engine 110, such as a temperature associated with gas turbine engine 110, an operational age of gas turbine engine 110, a size of gas turbine engine 110, etc. In some examples, and as discussed, engine starting rotational speed 332 corresponds to an optimized engine rotational speed, such as a speed at which powerhead compressor 140 feeds engine airflow 132 into combustion chamber 150 at a rate that facilitates and/or optimizes a stable and/or complete combustion of air-fuel mixture 134. In this manner, in various examples, it is not necessary that gas turbine engine 110 remains precisely at a particular engine starting rotational speed 332 in order to initiate combustion of air-fuel mixture 134 and/or operation of gas turbine engine 110, so long as the engine rotational speed is within engine starting speed envelope 330.
Turning to
As used herein, the term “torque curve,” as used to characterize the operation of engine starter 200, is intended to refer to a graph, a plot, and/or a series of values of the starter torque that are produced by engine starter 200 as a function of the starter rotational speed during the engine startup process. In this manner, and as described in more detail herein, maximum starter torque curve 300 illustrated in
In some examples, it may be undesirable and/or relatively inefficient to operate engine starter 200 to produce speed-dependent maximum torque value 302 at each value of the starter rotational speed during the engine startup process (e.g., in a manner that follows maximum starter torque curve 300). In particular, in some examples, such operation may accelerate the engine rotational speed overly rapidly for efficient initiation of operation of gas turbine engine 110, and/or may result in premature wear of one or more components of gas turbine engine starter system 100. As a more specific example,
As additionally shown in
As discussed, gas turbine engine starter system 100 is configured such that the torque curve followed by engine starter 200 during the engine startup process at least partially diverges from maximum starter torque curve 300, at least within spool-up time interval 350. In particular, in some examples, and as illustrated in
In many examples, and as described in more detail herein, gas turbine engine starter system 100 is configured to generate the starter torque such that the engine rotational speed of gas turbine engine 110 varies according to a predetermined and/or targeted acceleration profile during at least a portion of the engine startup process. In particular, in some examples, and with reference to
The precise form, instance, and/or selection of engine target acceleration profile 306 that is utilized in conjunction with a particular execution of the engine startup process may be based on any of a variety of factors.
As discussed in more detail herein, gas turbine engine starter system 100 generally is configured to operate engine starter 200 in such a manner that the actual engine rotational speed of gas turbine engine 110 during the engine startup process matches the series of engine startup speeds represented by engine target acceleration profile 306. However, it is to be understood that it is within the scope of the present disclosure that the actual engine rotational speed of gas turbine engine 110 is not exactly equal to the engine rotational speed prescribed by engine target acceleration profile 306 during the engine startup process. In particular, in some examples of the engine startup process, the engine rotational speed of gas turbine engine 110 deviates from the engine rotational speed represented by engine target acceleration profile 306 within at least a portion of the engine startup process by an average deviation that is at most 10%, at most 5%, and/or at most 1%.
As discussed, the precise form, instance, and/or configuration of regulated starter torque curve 310 that characterizes a particular instance and/or execution of the engine startup process is at least partially based upon the precise form, instance, and/or selection of engine target acceleration profile 306 that is utilized in conjunction with the particular instance and/or execution of the engine startup process. In this manner, regulated starter torque curve 310 may have any of a variety of forms, each of which depends at least in part on the corresponding engine target acceleration profile 306. In particular, the example of regulated starter torque curve 310 illustrated in
For example, and with reference to
Stated differently, first regulated starter torque curve 311 and second regulated starter torque curve 320 represent two of a broader plurality of examples of regulated starter torque curves 310 according to the present disclosure. More specifically, in the examples of
The examples of first regulated starter torque curve 311 and second regulated starter torque curve 320 presented in
In some examples, and as illustrated in
Such functionality is illustrated in
In some examples, and as discussed in more detail herein, dwell time interval 360 is not a predetermined and/or prescribed duration of time, but rather is at least partially based upon one or more measured and/or calculated factors that at least partially determine the beginning and/or the end of dwell time interval 360. In this manner, dwell time interval 360 may encompass any suitable interval of time, examples of which include at least 0.5 seconds (s), at least 1 s, at least 3 s, at least 5 s, and at most 10 s. In particular, in some examples, and as described in more detail herein, the end of dwell time interval 360 (i.e., the moment within the engine startup process at which dwell time interval 360 terminates) is at least partially based upon a measured property associated with the operation of gas turbine engine 110, and thus is not necessarily predetermined. Accordingly, in some such examples, the trajectory of the time evolution of the engine rotational speed is not defined by engine target acceleration profile 306 at times subsequent to the end of dwell time interval 360. In particular, although
Moreover, while
With continued reference to
In some examples, operating engine starter 200 to provide the starter torque to gas turbine engine 110 subsequent to dwell time interval 360 facilitates the acceleration of the engine rotational speed toward steady-state operational engine rotational speed 340. In particular, because maximum torque interval 370 corresponds to a time interval in which stable combustion has been initiated within combustion chamber 150 in some examples, the benefit to regulating speed-dependent regulated torque value 312 to be below speed-dependent maximum torque value 302 is at least partially obviated within this time interval. Accordingly, in such examples, there is relatively little or no consequence to operating engine starter 200 in a manner that delivers a maximum available amount of the starter torque to gas turbine engine 110 within maximum torque interval 370.
Moreover, in some examples, the operation of engine starter 200 within maximum torque interval 370 corresponds to an operational regime in which speed-dependent maximum torque value 302 is significantly lower than the corresponding value during operation within spool-up time interval 350 and/or dwell time interval 360. Accordingly, in such examples, operating engine starter 200 to produce speed-dependent maximum torque value 302 within maximum torque interval 370 nonetheless represents producing a lower value of the starter torque than during operation within spool-up time interval 350 and/or dwell time interval 360.
Returning to
Additionally or alternatively, in some examples, and as schematically illustrated in
Engine starter 200 may be operatively coupled to gas turbine engine 110 in any of a variety of manners. In some examples, starter torque output 202 is operatively coupled to engine shaft 120 and/or to powerhead compressor 140. In particular, in some examples, starter torque output 202 is operatively coupled to powerhead compressor 140 via engine shaft 120 in order to convey the starter torque to powerhead compressor 140 via engine shaft 120.
In some examples, and as schematically illustrated in
In some examples, and as schematically illustrated in
As used herein, the term “operatively coupled,” as used to describe a functional, structural, and/or mechanical relationship between two or more components of gas turbine engine 110 and/or of engine starter 200, is intended to refer to any configuration in which the two or more components are directly and/or indirectly coupled to one another via one or more structural components. As an example, starter motor 210 of engine starter 200 may be described as being operatively coupled to powerhead compressor 140 of gas turbine engine 110 in any of a variety of examples in which torque may be transferred from starter motor 210 to powerhead compressor 140, such as via one-way clutch mechanism 220, starter torque output 202, gearbox 102, and/or engine shaft 120.
Engine starter 200 may be configured to produce the starter torque in any of a variety of manners. In some examples, and as schematically illustrated in
In some examples, and as schematically illustrated in
In some examples, engine controller 190 is programmed to generate starter control signal 192 such that speed-dependent regulated torque value 312 of the starter torque that is produced by engine starter 200 is less than speed-dependent maximum torque value 302 of the starter torque at each starter rotational speed of a set, sequence, and/or interval of starter rotational speeds that are produced during at least a portion of spool-up time interval 350. Additionally or alternatively, in some examples, engine controller 190 is programmed to generate starter control signal 192 such that speed-dependent regulated torque value 312 of the starter torque is less than speed-dependent maximum torque value 302 of the starter torque at each starter rotational speed of a set, sequence, and/or interval of starter rotational speeds that are produced during at least a portion of dwell time interval 360.
Additionally or alternatively, in some examples, and as discussed, engine controller 190 is programmed to generate starter control signal 192 to regulate operation of engine starter 200 during at least a portion of maximum torque interval 370. In particular, in some examples, engine controller 190 is programmed to generate starter control signal 192 such that speed-dependent regulated torque value 312 of the starter torque is equal to speed-dependent maximum torque value 302 of the starter torque during at least a portion of maximum torque interval 370.
Additionally or alternatively, in some examples, engine controller 190 further is programmed to terminate operation of engine starter 200 to produce the starter torque in certain conditions. More specifically, in some examples, and with reference to
Additionally or alternatively, in some examples, engine controller 190 is programmed to determine engine target acceleration profile 306, such as based upon a measured and/or calculated condition of gas turbine engine starter system 100, of engine starter 200, and/or of gas turbine engine 110. As discussed, gas turbine engine starter system 100 generally is configured to operate engine starter 200 to accelerate the engine rotational speed according to engine target acceleration profile 306, which in turn may be selected, predetermined, calculated, generated, etc. prior to initiation of the engine startup process based upon any of a variety of factors. Accordingly, in some examples, and as described in more detail herein, engine controller 190 is configured to determine (e.g., to generate, calculate, and/or select) engine target acceleration profile 306 based upon one or more measured and/or calculated conditions.
In some examples, and as schematically illustrated in
In some examples, and as schematically illustrated in
When present, starter controller 240 may operate in any of a variety of manners to control operation of starter motor 210, such as based upon starter control signal 192. In some examples, starter controller 240 is configured to transmit, convey, and/or relay electrical power signal 194 to starter motor 210 to power engine starter 200. In some such examples, and as discussed, electrical power signal 194 is a signal with an electrical current and/or an electrical voltage that is modulated by engine controller 190 to produce a commanded starter torque. Additionally or alternatively, in some examples, starter controller 240 is configured to vary the electrical current and/or the electrical voltage of electrical power signal 194 to regulate operation of engine starter 200.
Engine controller 190 and/or starter controller 240 each may be any suitable device or devices that are configured to perform the functions of the controller discussed herein. For example, engine controller 190 and/or starter controller 240 each may include one or more of an electronic controller, a dedicated controller, a special-purpose controller, a personal computer, a special-purpose computer, a display device, a logic device, a memory device, and/or a memory device having non-transitory computer readable media suitable for storing computer-executable instructions for implementing aspects of systems and/or methods according to the present disclosure.
Additionally or alternatively, engine controller 190 and/or starter controller 240 each may include, or be configured to read, non-transitory computer readable storage, or memory, media suitable for storing computer-executable instructions, or software, for implementing methods or steps of methods according to the present disclosure. Examples of such media include CD-ROMs, disks, hard drives, flash memory, etc. As used herein, storage, or memory, devices and media having computer-executable instructions as well as computer-implemented methods and other methods according to the present disclosure are considered to be within the scope of subject matter deemed patentable in accordance with Section 101 of Title 35 of the United States Code.
Engine controller 190 may be configured to generate starter control signal 192 in any of a variety of manners and/or based upon any of a variety of factors. In particular, in various examples, and as discussed, engine controller 190 is programmed to generate starter control signal 192 such that the engine rotational speed follows engine target acceleration profile 306 during at least a portion of the engine startup process. Accordingly, in such examples, gas turbine engine starter system 100 may be configured to provide engine controller 190 with any of a variety of inputs such that starter control signal 192 operates to command engine starter 200 to produce a starter torque that yields an engine rotational speed according to engine target acceleration profile 306. Additionally or alternatively, engine controller 190 may be programmed to determine and/or generate engine target acceleration profile 306 in any of a variety of manners and/or based upon any of a variety of factors, such as may be based upon any of a variety of inputs provided to engine controller 190.
In some examples, and as schematically illustrated in
In some examples, and as schematically illustrated in
Additionally or alternatively, in some examples, gas turbine engine status signal 112 is at least partially based upon, and/or represents, a temperature associated with gas turbine engine 110. In particular, in some examples, and as schematically illustrated in
In some examples in which gas turbine engine status signal 112 includes EGT signal 184, engine controller 190 is programmed to generate starter control signal 192 at least partially based upon EGT signal 184. In particular, in some examples, the EGT that is measured by EGT sensor 182 is indicative of the state and/or status of the combustion process occurring within combustion chamber 150. Accordingly, in some examples, an indication that the EGT is rising significantly and/or rapidly is indicative of the initiation of a stable and/or self-sustaining combustion process within combustion chamber 150, which in turn may signal and/or prompt a transition from dwell time interval 360 to maximum torque interval 370. In this manner, in some such examples, the duration of dwell time interval 360 is not predetermined or prescribed, but instead is determined and/or defined within an given instance and/or execution of the engine startup process based upon the indication from EGT sensor 182 that the EGT is rising in a manner consistent with stable and/or self-sustaining combustion within combustion chamber 150.
Additionally or alternatively, in some examples, and as schematically illustrated in
In some examples in which gas turbine engine status signal 112 includes oil temperature signal 188, engine controller 190 is programmed to generate starter control signal 192 at least partially based upon oil temperature signal 188. In particular, in some examples, the oil temperature that is measured by oil temperature sensor 186 is indicative of a state of gas turbine engine 110 in a manner that may inform the selection and/or determination of engine target acceleration profile 306. As a more specific example, and as discussed, the selection and/or determination of engine target acceleration profile 306 may be performed such that, when gas turbine engine 110 is comparatively cold (as characterized, for example, by a comparatively low temperature indicated by oil temperature signal 188), engine target acceleration profile 306 represents a comparatively gradual acceleration of the engine rotational speed within spool-up time interval 350 and/or a comparatively low engine starting rotational speed 332 within dwell time interval 360. Accordingly, in some examples, engine controller 190 is programmed to determine engine target acceleration profile 306 at least partially based upon gas turbine engine status signal 112 and/or oil temperature signal 188.
Additionally or alternatively, in some examples, engine controller 190 is programmed to generate starter control signal 192 at least partially based upon a measured, calculated, and/or indicated state and/or status of engine starter 200. In particular, in some examples, and as schematically illustrated in
When utilized, starter status signal 242 may represent any of a variety of conditions associated with engine starter 200. In particular, in some examples, starter status signal 242 represents the starter rotational speed, a temperature of engine starter 200, maximum starter torque curve 300 associated with and/or characterizing engine starter 200, and/or an actual (e.g., real-time) value of the starter torque that is produced by engine starter 200. For example, in examples in which starter status signal 242 represents the starter rotational speed, maximum starter torque curve 300, and/or the actual value of the starter torque as produced by engine starter 200, such information thus may enable and/or facilitate generating starter control signal 192 to command engine starter 200 to produce a starter torque that is less than speed-dependent maximum torque value 302 corresponding to the indicated starter rotational speed. Additionally or alternatively, in some examples, engine controller 190 is programmed to determine engine target acceleration profile 306 at least partially based upon starter status signal 242, such as to ensure that engine target acceleration profile 306 corresponds to a functional capability of engine starter 200 as characterized by maximum starter torque curve 300.
Additionally or alternatively, in some examples, engine controller 190 is programmed to generate starter control signal 192 at least partially based upon a measured, calculated, and/or indicated state of vehicle 10 that includes and/or utilizes gas turbine engine starter system 100. In particular, in some examples, and as schematically illustrated in
For example, in some examples, engine controller 190 may be programmed to determine engine target acceleration profile 306 in such a manner that a comparatively low ambient temperature of air surrounding vehicle 10 corresponds to accelerating the engine rotational speed comparatively gradually within spool-up time interval 350 and/or maintaining the engine rotational speed at a comparatively low engine starting rotational speed 332 within dwell time interval 360.
As shown in
In the present disclosure, a process of accelerating the gas turbine engine equivalently may be described as a process of accelerating the engine rotational speed, of changing the engine rotational speed, of modulating the engine rotational speed, of increasing the engine rotational speed, and/or of decreasing the engine rotational speed. Examples of engine starting speed envelopes and/or of engine starting rotational speeds are disclosed herein with reference to engine starting speed envelope 330 and/or engine starting rotational speed 332, respectively. Examples of spool-up time intervals that may be utilized in conjunction with methods 400 are disclosed herein with reference to spool-up time interval 350.
In the present disclosure, methods 400 generally pertain to a set and/or sequence of steps that are performed during the engine startup process (e.g., during a particular instance and/or execution of the engine startup process). In some examples, methods 400 are performed entirely within the engine startup process. However, this is not required of all examples of methods 400, and it additionally is within the scope of the present disclosure that one or more steps of methods 400 are performed prior to or subsequent to the engine startup process. Additionally, while
As discussed, methods 400 include operating the engine starter to produce a starter torque that is less than a maximum torque that the engine starter is capable of producing at a particular starter rotational speed. In some examples, the engine starter is configured to produce a speed-dependent regulated torque value of the starter torque during operative use of the gas turbine engine starter system. In particular, in some such examples, the regulating the operation of the engine starter at 410 includes regulating such that, at each starter rotational speed of an interval of starter rotational speeds that are produce during at least a portion of the spool-up time interval, the speed-dependent regulated torque value is less than the speed-dependent maximum torque value. Examples of speed-dependent regulated torque values that may be utilized in conjunction with methods 400 are disclosed herein with reference to speed-dependent regulated torque value 312, such as may be represented and/or characterized by regulated starter torque curve 310.
The regulating the operation of the engine starter at 410 may include regulating in any of a variety of manners, such as based up any of a variety of sensed, measured, and/or calculated conditions and/or factors. In some examples, and as shown in
The transmitting the starter control signal at 416 may be performed in any of a variety of manners. In particular, in some examples, the engine starter includes a starter motor that is configured to produce the starter torque (such as starter motor 210 disclosed herein), and the transmitting the starter control signal at 416 includes transmitting the starter control signal directly to the starter motor.
In some such examples, the transmitting the starter control signal at 416 includes transmitting the electrical power signal to the starter motor, such as to power the starter motor with the starter control signal and/or with the electrical power signal. Additionally or alternatively, in some examples, the gas turbine engine starter system includes a starter controller configured to at least partially control operation of the engine starter, such as starter controller 240 disclosed herein. In some such examples, the transmitting the starter control signal at 416 includes transmitting the starter control signal to the starter controller.
In some examples, the generating the starter control signal at 412 includes generating such that the engine rotational speed follows a selected predetermined engine target acceleration profile during at least a portion of the spool-up time interval. Examples of selected predetermined engine target acceleration profiles that may be utilized in conjunction with methods 400 are disclosed herein with reference to selected predetermined engine target acceleration profile 306. In this manner, in such examples, and as described herein, the gas turbine engine starter system is configured to operate the engine starter in such a manner that the engine rotational speed of the gas turbine engine varies in time in a manner consistent with the selected predetermined engine target acceleration profile. In particular, in some examples, the generating the starter control signal at 412 includes repeatedly updating the starter control signal during the spool-up time interval such that engine rotational speed follows the selected predetermined engine target acceleration profile during at least a portion of the spool-up time interval.
The selected predetermined engine target acceleration profile that is utilized in conjunction with methods 400, such as during a particular instance and/or execution of the engine startup process, may be selected and/or determined in any of a variety of manners. In some examples, and as shown in
Additionally or alternatively, in some examples, and as shown in
Additionally or alternatively, in some examples, the gas turbine engine is incorporated into a vehicle that includes one or more vehicle status sensors, each of which is configured to generate and transmit a respective portion of a vehicle status signal that represents an operational condition of the vehicle. In some such examples, and as shown in
In some examples, methods 400 include operating the engine starter such that the engine rotational speed of the gas turbine engine remains within a range of engine rotational speeds that is conducive to initiation of stable and/or self-sustaining combustion within the gas turbine engine for a period of time. In particular, in some examples, and as shown in
In some examples in which methods 400 include the maintaining the engine rotational speed within the engine starting speed envelope at 420, methods 400 include regulating the operation of the engine starter such that the engine rotational speed remains within the engine starting speed envelope during the dwell time interval. In particular, in some examples, the regulating the operation of the engine starter at 410 includes generating the starter control signal such that, at each starter rotational speed of an interval of starter rotational speeds produced during at least a portion of the dwell time interval, the speed-dependent regulated torque value of the starter torque produced by the engine starter is less than the speed-dependent maximum torque value of the starter torque. In some such examples, the generating the starter control signal at 412 includes repeatedly updating the starter control signal during the dwell time interval such that the engine rotational speed remains within the engine starting speed envelope during the dwell time interval.
In some examples, methods 400 additionally include operating the engine starter to continue to provide the starter torque to the gas turbine engine after the dwell time interval, such as after initiation of a combustion process within the gas turbine engine. In particular, in some examples, and as shown in
In some examples, the generating the maximum starter torque at 422 is performed responsive to an indication that the gas turbine engine has initiated operation, and/or that stable and/or self-sustaining combustion has initiated within the gas turbine engine. In such examples, the generating the maximum starter torque at 422 may be performed responsive to any such indication. In particular, in some examples, the receiving the gas turbine engine status signal at 404 includes receiving an exhaust gas temperature (EGT) signal that indicates an EGT of combustion gases that are generated by the gas turbine engine. Accordingly, in some such examples, the generating the maximum starter torque at 422 is performed responsive of the EGT signal indicating that the EGT exceeds a threshold EGT, such as may be indicative of the initiation of stable and/or self-sustaining combustion within the gas turbine engine. Examples of combustion gases and/or of EGT signals that may be utilized in conjunction with methods 400 are disclosed herein with reference to combustion gases 136 and/or EGT signal 184, respectively. In some examples, the EGT signal is generated by an EGT sensor, such as EGT sensor 182 disclosed herein.
In some examples, and as shown in
Additionally, the ceasing the operation of the engine starter at 424 may be performed at any suitable point in the engine startup process. In some examples, the ceasing the operation of the engine starter at 424 is performed at the end of the maximum torque interval. Additionally or alternatively, in some examples, the ceasing the operation of the engine starter at 424 is performed responsive to the gas turbine engine status signal indicating that the engine rotational speed has reached a threshold cutoff speed that is a threshold percentage of a steady-state operational engine rotational speed associated with the gas turbine engine. In some such examples, the threshold percentage is at least 30%, at least 40%, at least 50%, at least 60%, at most 70%, at most 55%, at most 45%, and at most 35%. That is, in some examples, the indication that the engine rotational speed has reached the threshold cutoff speed defines and/or signals the end of the maximum torque interval, which in turn coincides with the ceasing the operation of the engine starter at 424. Examples of threshold cutoff speeds and/or of steady-state operational engine rotational speeds that may be utilized in conjunction with methods 400 are disclosed herein with reference to threshold cutoff speed 342 and/or steady-state operational engine rotational speed 340, respectively.
Illustrative, non-exclusive examples of inventive subject matter according to the present disclosure are described in the following enumerated paragraphs:
A1. A gas turbine engine starter system (100) for initiating operation, during an engine startup process, of a gas turbine engine (110) that includes an engine shaft (120) that is configured to rotate at an engine rotational speed, the gas turbine engine starter system (100) comprising:
an engine starter (200) configured to generate a starter torque during the engine startup process to initiate operation of the gas turbine engine (110) to produce an engine torque;
wherein the engine starter (200) includes a starter torque output (202) that is configured to rotate at a starter rotational speed and to convey the starter torque to the gas turbine engine (110) during the engine startup process to initiate operation of the gas turbine engine (110);
wherein the gas turbine engine (110) is characterized by an engine starting speed envelope (330) that encompasses a range of engine starting rotational speeds (332) corresponding to initiation of a combustion process within the gas turbine engine (110) during the engine startup process; wherein the engine startup process includes a spool-up time interval (350) in which the engine rotational speed increases from a non-operative engine rotational speed to a speed within the engine starting speed envelope (330); and wherein the gas turbine engine starter system (100) is configured such that, during operative use of the gas turbine engine starter system (100) and during at least a portion of the spool-up time interval (350), the starter torque is less than a speed-dependent maximum torque value (302) of the starter torque that the engine starter (200) is configured to produce.
A2. The gas turbine engine starter system (100) of paragraph A1, wherein the non-operative engine rotational speed is one or more of zero, approximately zero, and a negligible engine rotational speed.
A3. The gas turbine engine starter system (100) of any of paragraphs A1-A2, wherein the engine starter (200) is characterized by a maximum starter torque curve (300) that represents the speed-dependent maximum torque value (302) of the starter torque that the engine starter (200) is configured to produce as a function of the starter rotational speed.
A4. The gas turbine engine starter system (100) of any of paragraphs A1-A3, wherein the engine starter (200) is configured to produce a speed-dependent regulated torque value (312) of the starter torque during operative use of the gas turbine engine starter system (100); and wherein the gas turbine engine starter system (100) is configured such that, during operative use of the gas turbine engine starter system (100), the speed-dependent regulated torque value (312) of the starter torque is less than the speed-dependent maximum torque value (302) of the starter torque at each starter rotational speed of an interval of starter rotational speeds that are produced during at least a portion of the spool-up time interval (350).
A5. The gas turbine engine starter system (100) of paragraph A4, wherein the engine starter (200) is characterized by a regulated starter torque curve (310) during the engine startup process; and wherein the regulated starter torque curve (310) represents the speed-dependent regulated torque value (312) of the starter torque that is produced by the engine starter (200) as a function of the starter rotational speed.
A6. The gas turbine engine starter system (100) of any of paragraphs A1-A5, wherein the gas turbine engine starter system (100) is configured such that the engine starter (200) generates the starter torque such that the engine rotational speed follows a selected predetermined engine target acceleration profile (306) during at least a portion of the spool-up time interval (350).
A7. The gas turbine engine starter system (100) of paragraph A6, wherein the engine rotational speed of the gas turbine engine (110) deviates from the engine rotational speed represented by the selected predetermined engine target acceleration profile (306) within at least a portion of the engine startup process by an average deviation that is one or more of at most 10%, at most 5%, and at most 1%.
A8. The gas turbine engine starter system (100) of any of paragraphs A1-A7, further comprising the gas turbine engine (110).
A9. The gas turbine engine starter system (100) of any of paragraphs A1-A8, wherein the gas turbine engine (110) is operable to produce the engine torque and to convey the engine torque via the engine shaft (120).
A10. The gas turbine engine starter system (100) of any of paragraphs A1-A9, wherein the gas turbine engine (110) includes:
a powerhead compressor (140) configured to compress an engine airflow (132);
a combustion chamber (150) configured to combust an air-fuel mixture (134), which includes a mixture of the engine airflow (132) and a fuel flow (178), to produce combustion gases (136); and
a powerhead turbine (160) configured to extract energy from the combustion gases (136) to produce the engine torque.
A11. The gas turbine engine starter system (100) of paragraph A10, wherein the gas turbine engine (110) further includes a fuel pump (176) configured to convey the fuel flow (178) to the combustion chamber (150).
A12. The gas turbine engine starter system (100) of any of paragraphs A10-A11, wherein the gas turbine engine (110) further includes an ignition system (170) configured to initiate combustion of the air-fuel mixture (134) within the combustion chamber (150).
A13. The gas turbine engine starter system (100) of paragraph A12, wherein the ignition system (170) includes:
an ignitor plug (174) configured to produce an electrical spark to ignite the air-fuel mixture (134); and
an exciter (172) configured to convey a high-voltage electrical signal to the ignitor plug (174).
A14. The gas turbine engine starter system (100) of any of paragraphs A10-A13, wherein the starter torque output (202) is operatively coupled to the powerhead compressor (140) to convey the starter torque to the powerhead compressor (140).
A15. The gas turbine engine starter system (100) of any of paragraphs A10-A14, wherein the starter torque output (202) is operatively coupled to the engine shaft (120).
A16. The gas turbine engine starter system (100) of any of paragraphs A10-A15, wherein the starter torque output (202) is operatively coupled to the powerhead compressor (140) via the engine shaft (120).
A17. The gas turbine engine starter system (100) of any of paragraphs A10-A16, wherein the gas turbine engine (110) further includes an air intake (130) for introducing the engine airflow (132) into the powerhead compressor (140).
A18. The gas turbine engine starter system (100) of any of paragraphs A10-A17, wherein the gas turbine engine (110) further includes an exhaust outlet (180) for exhausting the combustion gases (136) from the gas turbine engine (110).
A19. The gas turbine engine starter system (100) of any of paragraphs A1-A18, further comprising a gearbox (102) that operatively interconnects the starter torque output (202) and the gas turbine engine (110).
A20. The gas turbine engine starter system (100) of paragraph A19, wherein the gearbox (102) is operatively coupled to the engine shaft (120).
A21. The gas turbine engine starter system (100) of any of paragraphs A1-A20, wherein the starter torque output (202) includes one or more of a gear, a pinion gear, and a splined mechanical interface.
A22. The gas turbine engine starter system (100) of any of paragraphs A1-A21, wherein the engine starter (200) includes a starter motor (210) configured to produce the starter torque.
A23. The gas turbine engine starter system (100) of paragraph A22, wherein the engine starter (200) includes a one-way clutch mechanism (220); and wherein the starter motor (210) is operatively coupled to the starter torque output (202) via the one-way clutch mechanism (220) to prevent the gas turbine engine (110) from driving the starter motor (210).
A24. The gas turbine engine starter system (100) of paragraph A22, wherein the starter motor (210) includes a starter generator (230) configured to receive a torque from the starter torque output (202) and to generate an electrical current during operation of the gas turbine engine (110).
A25. The gas turbine engine starter system (100) of any of paragraphs A1-A24, further comprising a starter power supply (104) configured to provide electrical power to the engine starter (200) to produce the starter torque.
A26. The gas turbine engine starter system (100) of paragraph A25, wherein the starter power supply (104) is spatially removed from each of the engine starter (200) and the gas turbine engine (110).
A27. The gas turbine engine starter system (100) of any of paragraphs A1-A26, further comprising an engine controller (190) programmed to generate and transmit a starter control signal (192) to at least partially control operation of the engine starter (200).
A28. The gas turbine engine starter system (100) of paragraph A27, wherein the engine controller (190) is programmed to generate the starter control signal (192) such that the engine rotational speed follows a/the selected predetermined engine target acceleration profile (306) during at least a portion of the spool-up time interval (350).
A29. The gas turbine engine starter system (100) of any of paragraphs A27-A28, wherein the engine controller (190) is programmed to generate the starter control signal (192) such that the speed-dependent regulated torque value (312) of the starter torque is less than the speed-dependent maximum torque value (302) of the starter torque at each starter rotational speed of an interval of starter rotational speeds that are produced during at least a portion of the spool-up time interval (350).
A30. The gas turbine engine starter system (100) of any of paragraphs A27-A29, wherein the starter control signal (192) includes, and optionally is, an electrical power signal (194) that powers the engine starter (200).
A31. The gas turbine engine starter system (100) of paragraph A30, wherein the engine controller (190) is programmed to modulate one or both of an electrical current and an electrical voltage of the electrical power signal (194) to regulate operation of the engine starter (200).
A32. The gas turbine engine starter system (100) of any of paragraphs A27-A31, wherein the engine controller (190) is programmed to transmit the starter control signal (192) to the engine starter (200).
A33. The gas turbine engine starter system (100) of paragraph A32, wherein the engine controller (190) is programmed to transmit the starter control signal (192) directly to a/the starter motor (210).
A34. The gas turbine engine starter system (100) of any of paragraphs A27-A33, further comprising a starter controller (240) configured to at least partially control operation of a/the starter motor (210); and wherein the engine controller (190) is programmed to transmit the starter control signal (192) to the starter controller (240).
A35. The gas turbine engine starter system (100) of paragraph A34, wherein the engine starter (200) includes the starter controller (240).
A36. The gas turbine engine starter system (100) of any of paragraphs A34-A35, wherein the starter controller (240) is configured to transmit an/the electrical power signal (194) to the starter motor (210) to power the engine starter (200).
A37. The gas turbine engine starter system (100) of any of paragraphs A34-A36, wherein the starter controller (240) is configured to vary one or both of an/the electrical current and an/the electrical voltage of the electrical power signal (194) to regulate operation of the engine starter (200).
A38. The gas turbine engine starter system (100) of any of paragraphs A34-A37, wherein the starter controller (240) is configured to generate a starter status signal (242) that represents an operating condition of the engine starter (200) and to transmit the starter status signal (242) to the engine controller (190); and wherein the starter control signal (192) is based, at least in part, on the starter status signal (242).
A39. The gas turbine engine starter system (100) of paragraph A38, wherein the starter status signal (242) represents one or more of:
(i) the starter rotational speed;
(ii) a temperature of the engine starter (200);
(iii) a/the maximum starter torque curve (300); and
(iv) an actual value of the starter torque produced by the engine starter (200).
A40. The gas turbine engine starter system (100) of any of paragraphs A27-A39, wherein the engine controller (190) is programmed to receive a gas turbine engine status signal (112) that represents an operating condition of the gas turbine engine (110); and wherein the starter control signal (192) is based, at least in part, on the gas turbine engine status signal (112).
A41. The gas turbine engine starter system (100) of paragraph A40, wherein the gas turbine engine status signal (112) includes an engine speed signal (124) that represents the engine rotational speed.
A42. The gas turbine engine starter system (100) of paragraph A41, wherein the gas turbine engine (110) further includes an engine speed sensor (122) that is configured to measure the engine rotational speed and to generate the engine speed signal (124).
A43. The gas turbine engine starter system (100) of paragraph A42, wherein the engine speed sensor (122) is operatively coupled to the engine shaft (120).
A44. The gas turbine engine starter system (100) of any of paragraphs A40-A43, wherein the gas turbine engine status signal (112) represents a temperature associated with the gas turbine engine (110).
A45. The gas turbine engine starter system (100) of paragraph A44, wherein the gas turbine engine status signal (112) includes an exhaust gas temperature (EGT) signal (184) that represents an exhaust gas temperature (EGT) of a/the combustion gases (136) as the combustion gases (136) are exhausted from the gas turbine engine (110).
A46. The gas turbine engine starter system (100) of paragraph A45, wherein the gas turbine engine status signal (112) includes the EGT signal (184).
A47. The gas turbine engine starter system (100) of any of paragraphs A45-A46, further comprising an EGT sensor (182) configured to measure the EGT of the combustion gases (136) as the combustion gases (136) are exhausted from the gas turbine engine (110); and wherein the EGT sensor (182) is configured to generate and transmit the EGT signal (184).
A48. The gas turbine engine starter system (100) of paragraph A47, wherein the EGT sensor (182) is positioned downstream of a/the powerhead turbine (160).
A49. The gas turbine engine starter system (100) of any of paragraphs A47-A48, wherein the EGT sensor (182) is positioned within an/the exhaust outlet (180).
A50. The gas turbine engine starter system (100) of any of paragraphs A44-A49, wherein the gas turbine engine status signal (112) includes an oil temperature signal (188) that represents a temperature of an oil utilized by the gas turbine engine (110).
A51. The gas turbine engine starter system (100) of paragraph A50, further comprising an oil temperature sensor (186) that is configured to generate and transmit the oil temperature signal (188).
A52. The gas turbine engine starter system (100) of paragraph A51, wherein the oil temperature sensor (186) is operatively coupled to a/the gearbox (102).
A53. The gas turbine engine starter system (100) of any of paragraphs A27-A52, wherein the gas turbine engine starter system (100) is incorporated into a vehicle (10) that includes one or more vehicle status sensors (22); wherein each vehicle status sensor (22) of the one or more vehicle status sensors (22) is configured to generate and transmit a respective portion of a vehicle status signal (24) that represents an operational condition of the vehicle (10); and wherein the starter control signal (192) is based, at least in part, on the vehicle status signal (24).
A54. The gas turbine engine starter system (100) of paragraph A53, wherein the vehicle status signal (24) represents one or more of:
(i) an ambient temperature of air surrounding the vehicle (10);
(ii) an ambient pressure of air surrounding the vehicle (10);
(iii) a speed at which the vehicle (10) is traveling; and
(iv) an altitude at which the vehicle (10) is traveling.
A55. The gas turbine engine starter system (100) of any of paragraphs A27-A54, wherein the engine controller (190) is programmed to repeatedly update the starter control signal (192) during the spool-up time interval (350), optionally such that the engine rotational speed follows a/the selected predetermined engine target acceleration profile (306) during at least a portion of the spool-up time interval (350).
A56. The gas turbine engine starter system (100) of any of paragraphs A27-A55, wherein the engine controller (190) is programmed to determine a/the selected predetermined engine target acceleration profile (306); and optionally wherein the engine controller (190) programmed to determine the selected predetermined engine target acceleration profile (306) based, at least in part, on one or more of a/the starter status signal (242), a/the gas turbine engine status signal (112), a/the oil temperature signal (188), and a/the vehicle status signal (24).
A57. The gas turbine engine starter system (100) of any of paragraphs A1-A56, wherein the engine startup process further includes a dwell time interval (360) that initiates immediately subsequent to the end of the spool-up time interval (350); and wherein the gas turbine engine starter system (100) is configured such that the engine rotational speed remains within the engine starting speed envelope (330) during the dwell time interval (360).
A58. The gas turbine engine starter system (100) of paragraph A57, wherein an/the engine controller (190) is programmed to generate a/the starter control signal (192) such that the engine rotational speed remains within the engine starting speed envelope (330) during the dwell time interval (360).
A59. The gas turbine engine starter system (100) of any of paragraphs A57-A58, wherein the gas turbine engine starter system (100) is configured such that a/the speed-dependent regulated torque value (312) of the starter torque is less than the speed-dependent maximum torque value (302) of the starter torque at each starter rotational speed of an interval of starter rotational speeds that are produced during at least a portion of the dwell time interval (360).
A60. The gas turbine engine starter system (100) of paragraph A59, wherein an/the engine controller (190) is programmed to generate an/the starter control signal (192) such that the speed-dependent regulated torque value (312) of the starter torque is less than the speed-dependent maximum torque value (302) of the starter torque at each starter rotational speed of an interval of starter rotational speeds that are produced during at least a portion of the dwell time interval (360).
A61. The gas turbine engine starter system (100) of any of paragraphs A57-A60, wherein an/the engine controller (190) is programmed to repeatedly update the starter control signal (192) during the dwell time interval (360), optionally such that the engine rotational speed remains within the engine starting speed envelope (330) during the dwell time interval (360).
A62. The gas turbine engine starter system (100) of any of paragraphs A1-A61, wherein the engine startup process further includes a maximum torque interval (370) that initiates immediately subsequent to the end of a/the dwell time interval (360); and wherein the gas turbine engine starter system (100) is configured such that, during operative use of the gas turbine engine starter system (100) during the maximum torque interval (370), the starter torque is equal to the speed-dependent maximum torque value (302).
A63. The gas turbine engine starter system (100) of paragraph A62, wherein a/the engine controller (190) is programmed to generate the starter control signal (192) such that a/the speed-dependent regulated torque value (312) of the starter torque is equal to the speed-dependent maximum torque value (302) of the starter torque during at least a portion of the maximum torque interval (370).
A64. The gas turbine engine starter system (100) of any of paragraphs A62-A63, wherein an/the engine controller (190) is programmed to generate a/the starter control signal (192) such that the maximum torque interval (370) terminates when the engine rotational speed reaches a threshold cutoff speed (342) that is a threshold percentage of a steady-state operational engine rotational speed (340); and wherein the threshold percentage is one or more of at least 30%, at least 40%, at least 50%, at least 60%, at most 70%, at most 55%, at most 45%, and at most 35%.
A65. The gas turbine engine starter system (100) of any of paragraphs A1-A64, wherein the gas turbine engine (110) is a component of an auxiliary power unit (APU) (30).
A66. The gas turbine engine starter system (100) of paragraph A65, wherein the APU (30) includes a load compressor (32) that is configured to compress a load compressor airflow (34) to generate a bleed air flow (36); and wherein the gas turbine engine (110) is configured such that the engine torque drives the load compressor (32).
A67. The gas turbine engine starter system (100) of paragraph A66, wherein the engine shaft (120) operatively couples the powerhead turbine (160) to the load compressor (32) to convey the engine torque from the powerhead turbine (160) to the load compressor (32).
A68. The gas turbine engine starter system (100) of any of paragraphs A1-A67, wherein the gas turbine engine (110) is a component of a turbofan engine (40).
A69. The gas turbine engine starter system (100) of paragraph A68, wherein the turbofan engine (40) includes a fan (42) that is configured to accelerate an airflow to produce a thrust; and wherein the gas turbine engine (110) is configured such that the engine torque drives rotation of the fan (42).
A70. The gas turbine engine starter system (100) of paragraph A69, wherein the engine shaft (120) operatively couples the powerhead turbine (160) to the fan (42) to convey the engine torque from the powerhead turbine (160) to the fan (42).
B1. A vehicle (10) comprising the gas turbine engine starter system (100) of any of paragraphs A1-A70.
B2. The vehicle (10) of paragraph B1, wherein the vehicle (10) is an aircraft (20).
B3. The vehicle (10) of paragraph B2, wherein the aircraft (20) includes a/the turbofan engine (40); and wherein the turbofan engine (40) includes the gas turbine engine (110).
B4. The vehicle (10) of any of paragraphs B2-B3, wherein the aircraft (20) includes an/the APU (30); and wherein the APU (30) includes the gas turbine engine (110).
C1. A method (400) of operating a gas turbine engine starter system (100) to initiate operation of a gas turbine engine (110) during an engine startup process, wherein the gas turbine engine starter system (100) includes an engine starter (200) configured to generate a starter torque during the engine startup process to initiate operation of the gas turbine engine (110), and an engine controller (190) programmed to generate and transmit a starter control signal (192) to the engine starter (200), the method (400) comprising:
regulating (410), with the engine controller (190), the operation of the engine starter (200);
wherein the regulating (410) the operation of the engine starter (200) includes accelerating (418) the gas turbine engine (110) to bring an engine rotational speed of the gas turbine engine (110) to within an engine starting speed envelope (330) that encompasses a range of engine starting rotational speeds (332) corresponding to initiation of a combustion process within the gas turbine engine (110) during the engine startup process; and
wherein the accelerating (418) the gas turbine engine (110) includes operating the engine starter (200) such that the starter torque is less than a speed-dependent maximum torque value (302) of the starter torque that the engine starter (200) is configured to produce during at least a portion of a spool-up time interval (350) of the engine startup process in which the engine rotational speed increases from a non-operative engine rotational speed to a speed within the engine starting speed envelope (330).
C2. The method (400) of paragraph C1, wherein the method (400) is performed entirely within the engine startup process.
C3. The method (400) of any of paragraphs C1-C2, wherein the engine starter (200) is configured to produce a speed-dependent regulated torque value (312) of the starter torque during operative use of the gas turbine engine starter system (100); and wherein the regulating (410) the operation of the engine starter (200) includes regulating such that the speed-dependent regulated torque value (312) of the starter torque is less than the speed-dependent maximum torque value (302) of the starter torque at each starter rotational speed of an interval of starter rotational speeds that are produced during at least a portion of the spool-up time interval (350).
C4. The method (400) of any of paragraphs C1-C3, wherein the regulating (410) the operation of the engine starter (200) includes:
generating (412), with the engine controller (190), the starter control signal (192); and
transmitting (416), with the engine controller (190), the starter control signal (192) to the engine starter (200).
C5. The method (400) of paragraph C4, wherein the generating (412) the starter control signal (192) includes generating (414) an electrical power signal (194) that powers the engine starter (200).
C6. The method (400) of paragraph C5, wherein the generating (412) the starter control signal (192) includes modulating one or both of an electrical current and an electrical voltage of the electrical power signal (194).
C7. The method (400) of any of paragraphs C4-C6, wherein the engine starter (200) includes a starter motor (210) configured to produce the starter torque; and wherein the transmitting (416) the starter control signal (192) to the engine starter (200) includes transmitting the starter control signal (192) directly to the starter motor (210).
C8. The method (400) of paragraph C7, wherein the transmitting (416) the starter control signal (192) to the engine starter (200) includes transmitting the electrical power signal (194) to the starter motor (210).
C9. The method (400) of any of paragraphs C4-C8, wherein the engine starter (200) includes a/the starter motor (210) configured to produce the starter torque; wherein the gas turbine engine starter system (100) further includes a starter controller (240) configured to at least partially control operation of the starter motor (210); and wherein the transmitting (416) the starter control signal (192) includes transmitting the starter control signal (192) to the starter controller (240).
C10. The method (400) of any of paragraphs C4-C9, wherein the generating (412) the starter control signal (192) includes generating such that the engine rotational speed follows a selected predetermined engine target acceleration profile (306) during at least a portion of the spool-up time interval (350).
C11. The method (400) of any of paragraphs C4-C10, wherein the generating (412) the starter control signal (192) includes repeatedly updating the starter control signal (192) during the spool-up time interval (350) such that the engine rotational speed follows a/the selected predetermined engine target acceleration profile (306) during at least a portion of the spool-up time interval (350).
C12. The method (400) of any of paragraphs C1-C11, further comprising, prior to the regulating (410) the operation of the engine starter (200), determining (408), with the engine controller (190), a/the selected predetermined engine target acceleration profile (306).
C13. The method (400) of any of paragraphs C1-C12, further comprising:
receiving (402), with the engine controller (190), a starter status signal (242) that represents an operating condition of the engine starter (200); and
wherein the regulating (410) the operation of the engine starter (200) is based, at least in part, on the starter status signal (242).
C14. The method (400) of paragraph C13, wherein the generating (412) the starter control signal (192) is based, at least in part, on the starter status signal (242).
C15. The method (400) of any of paragraphs C13-C14, wherein a/the determining (408) the selected predetermined engine target acceleration profile (306) is based, at least in part, on the starter status signal (242).
C16. The method (400) of any of paragraphs C1-C15, further comprising:
receiving (404), with the engine controller (190), a gas turbine engine status signal (112) that represents an operating condition of the gas turbine engine (110); and
wherein the regulating (410) the operation of the engine starter (200) is based, at least in part, on the gas turbine engine status signal (112).
C17. The method (400) of paragraph C16, wherein the generating (412) the starter control signal (192) is based, at least in part, on the gas turbine engine status signal (112).
C18. The method (400) of any of paragraphs C16-C17, wherein a/the determining (408) the selected determined engine target acceleration profile (306) is based, at least in part, on the gas turbine engine status signal (112).
C19. The method (400) of any of paragraphs C1-C18, wherein the gas turbine engine starter system (100) is incorporated into a vehicle (10) that includes one or more vehicle status sensors (22), wherein each vehicle status sensor (22) of the one or more vehicle status sensors (22) is configured to generate and transmit a respective portion of a vehicle status signal (24) that represents an operational condition of the vehicle (10);
wherein the method (400) further comprises:
receiving (406), with the engine controller (190), the vehicle status signal (24); and
wherein the regulating (410) the operation of the engine starter (200) is based, at least in part, on the vehicle status signal (24).
C20. The method (400) of paragraph C19, wherein the generating (412) the starter control signal (192) is based, at least in part, on the vehicle status signal (24).
C21. The method (400) of any of paragraphs C19-C20, wherein a/the determining (408) the selected predetermined engine target acceleration profile (306) is based, at least in part, on the vehicle status signal (24).
C22. The method (400) of any of paragraphs C1-C21, wherein the regulating (410) the operation of the engine starter (200) further includes maintaining (420) the engine rotational speed within the engine starting speed envelope (330) during a dwell time interval (360) of the engine startup process that initiates immediately subsequent to the end of the spool-up time interval (350).
C23. The method (400) of paragraph C22, wherein the regulating (410) the operation of the engine starter (200) includes generating the starter control signal (192) such that a/the speed-dependent regulated torque value (312) the starter torque is less than a/the speed-dependent maximum torque value (302) of the starter torque at each starter rotational speed of an interval of starter rotational speeds that are produced during at least a portion of the dwell time interval (360).
C24. The method (400) of any of paragraphs C22-C23, wherein the generating (412) the starter control signal (192) includes repeatedly updating the starter control signal (192) during the dwell time interval (360) such that the engine rotational speed remains within the engine starting speed envelope (330) during the dwell time interval (360).
C25. The method (400) of any of paragraphs C1-C24, wherein the regulating (410) the operation of the engine starter (200) further includes, subsequent to the maintaining (420) the engine rotational speed within the engine starting speed envelope (330), generating (422), with the engine starter (200), a maximum starter torque during a maximum torque interval (370) of the engine startup process that initiates immediately subsequent to the end of a/the dwell time interval (360).
C26. The method (400) of paragraph C25, wherein the generating (422) the maximum starter torque includes a/the generating (412) the starter control signal (192) such that a/the speed-dependent regulated torque value (312) of the starter torque is equal to the speed-dependent maximum torque value (302) of the starter torque during the maximum torque interval (370).
C27. The method (400) of any of paragraphs C25-C26, wherein the generating (422) the maximum starter torque is performed responsive to an indication that the gas turbine engine (110) has initiated operation, optionally an indication that stable combustion has initiated within the gas turbine engine (110).
C28. The method (400) of any of paragraphs C25-C27, wherein a/the receiving (404) the gas turbine engine status signal (112) includes receiving an exhaust gas temperature (EGT) signal (184) that indicates an EGT of combustion gases (136) generated by the gas turbine engine (110); and wherein the generating (422) the maximum starter torque is performed responsive to the EGT signal (184) indicating that the EGT exceeds a threshold EGT.
C29. The method (400) of any of paragraphs C1-C28, wherein the regulating (410) the operation of the engine starter (200) further includes ceasing (424) operation of the engine starter (200).
C30. The method (400) of paragraph C29, wherein the ceasing (424) the operation of the engine starter (200) includes ceasing to transmit the starter control signal (192) to the engine starter (200).
C31. The method (400) of any of paragraphs C29-C30, wherein the ceasing (424) the operation of the engine starter (200) is performed at the end of a/the maximum torque interval (370).
C32. The method (400) of any of paragraphs C29-C31, wherein the ceasing (424) the operation of the engine starter (200) is performed responsive to a/the gas turbine engine status signal (112) indicating that the engine rotational speed has reached a threshold cutoff speed (342) that is a threshold percentage of a steady-state operational engine rotational speed (340); and wherein the threshold percentage is one or more of at least 30%, at least 40%, at least 50%, at least 60%, at most 70%, at most 55%, at most 45%, and at most 35%.
C33. The method (400) of any of paragraphs C1-C32, wherein the gas turbine engine starter system (100) is the gas turbine engine starter system (100) of any of paragraphs A1-A70.
As used herein, the phrase “at least substantially,” when modifying a degree or relationship, includes not only the recited “substantial” degree or relationship, but also the full extent of the recited degree or relationship. A substantial amount of a recited degree or relationship may include at least 75% of the recited degree or relationship. For example, a first direction that is at least substantially parallel to a second direction includes a first direction that is within an angular deviation of 22.5° relative to the second direction and also includes a first direction that is identical to the second direction.
As used herein, the phrase “nominally fully,” when modifying a degree or relationship, includes the full extent of the recited degree or relationship as well as degrees or relationships that differ from the full extent of the recited degree or relationship by up to 1%. For example, a first direction that is nominally fully parallel to a second direction includes a first direction that is within an angular deviation of 0.9° relative to the second direction and also includes a first direction that is identical to the second direction. In this manner, the phrase “nominally fully” may be substituted in place of the phrase “at least substantially.” Stated differently, as used herein, the phrase “at least substantially” is intended to encompass degrees or relationships that are described with the phrase “nominally fully.” Similarly, as used herein, the phrase “nominally equal,” as used to compare a first quantity and a second quantity, describes examples in which the first quantity and the second quantity are exactly equal to one another, as well as examples in which the first quantity and the second quantity differ from one another by up to 1%.
As used herein, the terms “selective” and “selectively,” when modifying an action, movement, configuration, or other activity of one or more components or characteristics of an apparatus, mean that the specific action, movement, configuration, or other activity is a direct or indirect result of one or more dynamic processes, as described herein. The terms “selective” and “selectively” thus may characterize an activity that is a direct or indirect result of user manipulation of an aspect of, or one or more components of, the apparatus, or may characterize a process that occurs automatically, such as via the mechanisms disclosed herein.
As used herein, the terms “adapted” and “configured” mean that the element, component, or other subject matter is designed and/or intended to perform a given function. Thus, the use of the terms “adapted” and “configured” should not be construed to mean that a given element, component, or other subject matter is simply “capable of” performing a given function but that the element, component, and/or other subject matter is specifically selected, created, implemented, utilized, programmed, and/or designed for the purpose of performing the function. It is also within the scope of the present disclosure that elements, components, and/or other recited subject matter that is recited as being adapted to perform a particular function may additionally or alternatively be described as being configured to perform that function, and vice versa. Similarly, subject matter that is recited as being configured to perform a particular function may additionally or alternatively be described as being operative to perform that function.
As used herein, the term “and/or” placed between a first entity and a second entity means one of (1) the first entity, (2) the second entity, and (3) the first entity and the second entity. Multiple entries listed with “and/or” should be construed in the same manner, i.e., “one or more” of the entities so conjoined. Other entities optionally may be present other than the entities specifically identified by the “and/or” clause, whether related or unrelated to those entities specifically identified. Thus, as a non-limiting example, a reference to “A and/or B,” when used in conjunction with open-ended language such as “comprising,” may refer, in one example, to A only (optionally including entities other than B); in another example, to B only (optionally including entities other than A); in yet another example, to both A and B (optionally including other entities). These entities may refer to elements, actions, structures, steps, operations, values, and the like.
As used herein, the phrase “at least one,” in reference to a list of one or more entities should be understood to mean at least one entity selected from any one or more of the entities in the list of entities, but not necessarily including at least one of each and every entity specifically listed within the list of entities and not excluding any combinations of entities in the list of entities. This definition also allows that entities may optionally be present other than the entities specifically identified within the list of entities to which the phrase “at least one” refers, whether related or unrelated to those entities specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) may refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including entities other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including entities other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other entities). In other words, the phrases “at least one,” “one or more,” and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B, and C,” “at least one of A, B, or C,” “one or more of A, B, and C,” “one or more of A, B, or C,” and “A, B, and/or C” may mean A alone, B alone, C alone, A and B together, A and C together, B and C together, A, B, and C together, and optionally any of the above in combination with at least one other entity.
As used herein, the phrase, “for example,” the phrase, “as an example,” and/or simply the term “example,” when used with reference to one or more components, features, details, structures, embodiments, and/or methods according to the present disclosure, are intended to convey that the described component, feature, detail, structure, embodiment, and/or method is an illustrative, non-exclusive example of components, features, details, structures, embodiments, and/or methods according to the present disclosure. Thus, the described component, feature, detail, structure, embodiment, and/or method is not intended to be limiting, required, or exclusive/exhaustive; and other components, features, details, structures, embodiments, and/or methods, including structurally and/or functionally similar and/or equivalent components, features, details, structures, embodiments, and/or methods, are also within the scope of the present disclosure.
In the present disclosure, several of the illustrative, non-exclusive examples have been discussed and/or presented in the context of flow diagrams, or flow charts, in which the methods are shown and described as a series of blocks, or steps. Unless specifically set forth in the accompanying description, it is within the scope of the present disclosure that the order of the blocks may vary from the illustrated order in the flow diagram, including with two or more of the blocks (or steps) occurring in a different order, concurrently, and/or repeatedly. It is also within the scope of the present disclosure that the blocks, or steps, may be implemented as logic, which also may be described as implementing the blocks, or steps, as logics. In some applications, the blocks, or steps, may represent expressions and/or actions to be performed by functionally equivalent circuits or other logic devices. The illustrated blocks may, but are not required to, represent executable instructions that cause a computer, processor, and/or other logic device to respond, to perform an action, to change states, to generate an output or display, and/or to make decisions.
The various disclosed elements of apparatuses and systems and steps of methods disclosed herein are not required to all apparatuses, systems, and methods according to the present disclosure, and the present disclosure includes all novel and non-obvious combinations and subcombinations of the various elements and steps disclosed herein. Moreover, one or more of the various elements and steps disclosed herein may define independent inventive subject matter that is separate and apart from the whole of a disclosed apparatus, system, or method. Accordingly, such inventive subject matter is not required to be associated with the specific apparatuses, systems, and methods that are expressly disclosed herein and such inventive subject matter may find utility in apparatuses, systems, and/or methods that are not expressly disclosed herein.
It is believed that the disclosure set forth above encompasses multiple distinct inventions with independent utility. While each of these inventions has been disclosed in its preferred form, the specific embodiments thereof as disclosed and illustrated herein are not to be considered in a limiting sense as numerous variations are possible. The subject matter of the inventions includes all novel and non-obvious combinations and subcombinations of the various elements, features, functions and/or properties disclosed herein. Similarly, where the claims recite “a” or “a first” element or the equivalent thereof, such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements.
It is believed that the following claims particularly point out certain combinations and subcombinations that are directed to one of the disclosed inventions and are novel and non-obvious. Inventions embodied in other combinations and subcombinations of features, functions, elements, and/or properties may be claimed through amendment of the present claims or presentation of new claims in this or a related application. Such amended or new claims, whether they are directed to a different invention or directed to the same invention, whether different, broader, narrower, or equal in scope to the original claims, are also regarded as included within the subject matter of the inventions of the present disclosure.