Patent Application
20190032575
This disclosure relates generally to the thermal management of gas combustion in an engine environment. More specifically, this disclosure relates to a method of making and using thermal measurements to monitor and adjust the performance of a gas combustion engine.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
The performance of a gas combustion engine is directly related to the maximum temperature achievable within the combustion chamber. For example, in a turbine engine continuous power or thrust is produced by a fast-moving flow of combustion gases that cause a rotor fitted with blades to revolve. The type of materials used to form the engine components (e.g., turbine blades, etc.) limits the magnitude of this thrust. As the push for higher thrust and greater efficiency drives engine temperatures closer to the limits associated with the materials used in the construction of the engine, it is becoming increasingly important to be able to measure and control these temperatures. In addition, design engineers need to know how blade temperatures respond to design changes, and maintenance personnel need to know to what temperatures engine components are exposed.
In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
The present disclosure generally provides a temperature control system and measurement method where individual smart thermocouple elements have integral electronics to provide a pre-conditioned digital signal. These digital temperature signals are communicated through a network to a control unit or engine controller that is capable of individually monitoring all of the temperature signals. During use, the temperature data is logged in real-time with optimized accuracy and response time. Upon analysis of the digital temperature signals, the engine controller can either decrease the fuel flow to one or more of the higher temperature zones or increase the fuel flow to one or more of the lower temperature zones in the combustion chamber.
The following description is merely exemplary in nature and is in no way intended to limit the present disclosure or its application or uses. For example, the temperature control system made and used according to the teachings contained herein is described throughout the present disclosure in conjunction with a gas turbine engine in order to more fully illustrate the temperature control system and the use thereof. The incorporation and use of such a temperature control system in other applications, including without limitation, a gas piston engine, or the like are contemplated to be within the scope of the present disclosure. In other words, the gas combustion engine may be a gas turbine engine or a gas piston engine; alternatively, the gas combustion engine is a gas turbine engine. It should be understood that throughout the description, corresponding reference numerals indicate like or corresponding parts and features.
Referring to
The conventional method of measuring the exhaust gas or turbine gas temperature uses two arrays of thermocouples to monitor engine temperature at 12 to 18 locations around the engine. These arrays represent a dual redundant configuration for safety and control functions. Each of the thermocouple arrays average the outputs of 6 to 8 individual thermocouple nodes to generate an average temperature that is representative of the engine operation. The use of this averaging function facilitates efficiency and provides redundancy. Although the individual thermocouples measure engine temperatures at each of the burner locations or in each of the combustion zones, the measured output is often misleading because the average engine temperature is used instead of the actual high and low temperatures measured by each thermocouple during operation. In addition, the average output may obscure a problem with a single combustor or be unable to note the location of an individual thermocouple failure or fault.
Referring now to
The temperature control system 50 of the present disclosure provides for improvement in engine 1 operation. Peak engine performance can be attained via the accurate and instantaneous monitoring of temperatures in each combustion zone 8. The temperature control system 50 allows the control unit 44 to identify in real-time an individual combustion zone 8 that is underperforming and adjust an engine operating parameter. In this manner, such control will allow for more efficient fuel burning, decreased emissions, and increased life of various components in the combustion engine. When desirable, more than one temperature control system 50(a, b) may be utilized to monitor and control the performance of a single combustion engine 1.
In addition, the temperature control system 50 of the present disclosure allows the control unit 44 to identify a failure with a thermal sensor 25 and to initiate an appropriate maintenance procedure. Each thermal sensor 25 is designed to operate within acceptable performance limits for a number of cycles that surpasses the point at which the engine is scheduled for maintenance and/or replacement of degraded components. In order for the engine to continue to operate at the same level of thrust as a new engine, it must operate hotter and/or faster in order to account for the deterioration of components. This shift from nominal operation increases with use and will eventually reach a point that exceeds the expected performance and/or recommended safety limit. Any sensor degradation or failure thereof cannot be tolerated, because it will further compound the degradation of the engine.
Referring once again to
The combustion chamber 7 as depicted in
Still referring to
The amount of fuel supplied to and mixed with the amount of air entering the combustion chamber depends upon the magnitude of the increase or decrease in temperature that is required or desired. Air entering the combustion chamber may exhibit velocities that exceed 100 m/s, alternatively between about 30 to 60 m/s for stationary engines, and between about 50 to 80 m/s for aircraft engines. The temperature in a combustion engine may range from about 850° C. to about 1,700° C. and as previously stated is limited by the characteristics of the materials from which the turbine blades and vanes are made. The air enters the combustion chamber at a temperature that is in the range of about 200° C. to about 550° C. due to the heating caused by compression. Thus, the temperature rise due to the combustion of fuel in the combustion chamber is expected to be in the range of about 650° C. to about 1150° C. This temperature rise may be achieved by varying the air to fuel ratio present in the combustion chamber between about 25:1 to about 150:1; alternatively in the range of 45:1 to 130:1; alternatively between about 65:1 to about 110:1.
Referring again to
Referring now to
The thermocouple element 27 may include, without limitation, a type of optical fiber sensor, pyrometer, or a Seebeck-type element. Optical fiber sensors or pyrometers may measure thermal radiation using one or more line of sight diagnostic techniques. A Seebeck-type element measures the electric potential between dissimilar metals. More specifically, these thermocouples measure the voltage produced by a temperature difference between two junctions formed between two thermoelectrically dissimilar metals (positive/negative). While any two metals with different thermal emissivity (c) can be used to produce a thermocouple, a small number of metals (both pure and alloys) are conventionally used due to their stability, linearity, reproducibility, and high temperature capability. Several examples of the various metal combinations that may be used to form a thermocouple are provided, without limitation, in Table 1 along with a description of their approximate limiting operating temperature and environments. The selection of specific metal combinations for use in any application is based upon the expected temperature range for the given application and the atmosphere or environment to which the thermocouple is to be exposed. A protective sheath may be optionally utilized to provide a barrier between the Seebeck-type element and the environment. This protective sheath may include, but not be limited to, a thin metallic outer layer and a ceramic or metal oxide-insulating layer, which is located between the outer metallic layer and the inner metal wires.
One skilled in the art will understand that the thermal sensor 25 may be directly wired 33 to the communications bus 42 as shown in
The control unit may be, without limitation, an electronic control unit (ECU), an electronic engine control (EEC) unit, or a full authority digital engine controller (FADEC). The control unit may be integrated with a fuel parameters measurement unit (FPMU), a fuel control unit (FCU), or fuel flow regulator (FFR). The FCU, FFR, or FPMU responds to the control unit's commands and performs the functions necessary, desired, and/or requested for engine operation and protection.
The control unit uses the signals from the temperature sensors to determine the required fuel mixture and ignition timing for the next combustion event in each combustion zone. The required quantity of fuel is injected into each combustion zone at the appropriate time, with respect to crank position, by a solenoid-style fuel injector. The injector's control coil may be driven directly by the associated control unit.
In addition, a Full Authority Digital Engine Control System (FADEC) is a total system for the control of an engine. The FADEC receives all the necessary data for engine operation and can assume virtually all of the steady state and transient control functions. Thus, fuel system components may be reduced to a pump, control valve and injector with the functioning of each being controllable by the FADEC. The FADEC's main purpose is to provide optimum engine efficiency for a given flight condition. Thus, the FADEC can monitor all of the normal engine parameters, including temperature, in order to avoid exceeding safety or performance limitations while controlling the engine through all modes of operation. FADECs are available for use with for piston engines and turbine engines.
According to another aspect of the present disclosure, a method of managing the thermal output of a combustion engine is provided. The temperature control system used in this method comprises a plurality of smart thermal sensors, wherein at least one smart thermal sensor is located in each of the combustion zones; a communication bus; and a control unit as previously discussed above and further defined herein.
Referring now to
The smart thermal sensor used in this method 100 comprises a thermocouple element, optionally, an analog to digital converter, and optionally, a protective sheath. The smart thermal sensor converts the measured temperature from an analog thermal signal to a digital thermal signal prior to transmission of the thermal signal to the communication bus. The gas combustion engine for use of this method 100 may include a gas turbine engine or a gas piston engine having a plurality of combustion zones ranging from 2 to 18. The control unit is an electronic control unit (ECU), an electronic engine control (EEC) unit, or a full authority digital engine controller (FADEC).
Still referring to
According to another aspect of the present disclosure, the use of the temperature control system comprising a plurality of smart thermal sensors integrated with a gas combustion engine having a plurality of combustion zones as described herein in order to adjust one or more operating parameters of the engine is contemplated. This temperature control system may be used according to the method described in
For the purpose of this disclosure, the terms “about” and “substantially” are used herein with respect to measurable values and ranges due to expected variations known to those skilled in the art (e.g., limitations and variability in measurements).
The recitations of numerical ranges by endpoints include the endpoints and all numbers within that numerical range. For example, a concentration ranging from 40% by weight to 60% by weight includes concentrations of 40% by weight, 60% by weight, and all concentrations there between (e.g., 40.1%, 41%, 45%, 50%, 52.5%, 55%, 59%, etc.).
The terms “at least one” and “one or more of’ an element are used interchangeably and may have the same meaning. These terms, which refer to the inclusion of a single element or a plurality of the elements, may also be represented by the suffix “(s)” at the end of the element. For example, “at least one fiber”, “one or more fibers”, and “fiber(s)” may be used interchangeably and are intended to have the same meaning.
To clarify the use of and to hereby provide notice to the public, the phrases “at least one of <A>, <B>, . . . and <N>” or “at least one of <A>, <B>, <N>, or combinations thereof” or “<A>, <B>, . . . and/or <N>” are defined by the Applicant in the broadest sense, superseding any other implied definitions hereinbefore or hereinafter unless expressly asserted by the Applicant to the contrary, to mean one or more elements selected from the group comprising A, B, . . . and N. In other words, the phrases mean any combination of one or more of the elements A, B, . . . or N including any one element alone or the one element in combination with one or more of the other elements, which may also include, in combination, additional elements not listed.
Within this specification, embodiments have been described in a way which enables a clear and concise specification to be written, but it is intended and will be appreciated that embodiments may be variously combined or separated without parting from the invention. For example, it will be appreciated that all preferred features described herein are applicable to all aspects of the invention described herein.
The subject-matter of the disclosure may also relate, among others, to the following aspects:
Aspect 1: A temperature control system integrated with a gas combustion engine that includes a plurality of combustion zones. The temperature control system comprises a plurality of smart thermal sensors, wherein the smart thermal sensors are located such that at least one smart thermal sensor measures a temperature in real-time for each of the combustion zones; a communication bus through which a thermal signal from each of the smart thermal sensors is transmitted; and a control unit that receives the thermal signals from the communication bus. The control unit uses the thermal signals to adjust one or more operating parameters of the gas combustion engine.
Aspect 2—The temperature control system according to Aspect 1, wherein the smart thermal sensor outputs a digital signal to the communication bus.
Aspect 3—The temperature control system according to Aspect 2, wherein the smart thermal sensor comprises a thermocouple element, an analog to digital signal converter, and optionally, a protective sheath.
Aspect 4—The temperature control system according to any of Aspects 1-3, wherein the gas combustion engine is a gas turbine engine or a gas piston engine.
Aspect 5—The temperature control system according to Aspect 4, wherein the gas combustion engine is a gas turbine engine.
Aspect 6—The temperature control system according to any of Aspects 1-5, wherein number of combustion zones ranges from 2 to 18.
Aspect 7—The temperature control system according to Aspect 6, wherein the number of combustion zones ranges from 4 to 16.
Aspect 8—The temperature control system according to any of Aspects 1-7, wherein the control unit is an electronic control unit (ECU), an electronic engine control (EEC) unit, or a full authority digital engine controller (FADEC).
Aspect 9—The temperature control system according to any of Aspects 1-8, wherein the control unit identifies a failure with one or more of the thermal sensors.
Aspect 10—The temperature control system according to any of Aspects 1-8, wherein the gas combustion engine further comprises a plurality of fuel injectors, such that fuel flows through at least one fuel injector into each of the combustion zones.
Aspect 11—The temperature control system according to Aspect 10, wherein the control unit decreases the flow of fuel through one or more of the fuel injectors into at least one combustion zone when the control unit determines the temperature in that at least one combustion zone is higher than the temperatures measured for the other combustion zones.
Aspect 12—The temperature control system according to Aspect 10, wherein the control unit increases the flow of fluid through one or more of the fuel injectors into at least one combustion zone when the control unit determines the temperature in that at least one combustion zone is lower than the temperatures measured for the other combustion zones.
Aspect 13—A method of managing the thermal output of a combustion engine comprises the following steps: providing a gas combustion engine that has a plurality of combustion zones; providing one or more temperature control systems integrated with the gas combustion engine; measuring the temperature in each of the combustion zones with smart thermal sensors; transmitting a thermal signal from each of the smart thermal sensors to a communication bus; and allowing the control unit to perform multiple functions. The multiple functions performed by the control unit include receiving the thermal signals from the communication bus, using the thermal signals to determine the need to adjust one or more operating parameters of the gas combustion engine, and adjusting one or more of the operating parameters. The temperature control system comprises a plurality of smart thermal sensors, a communication bus, and a control unit with at least one smart thermal sensor being located in each of the combustion zones.
Aspect 14—The method according to Aspect 13, wherein the smart thermal sensor comprises a thermocouple element, an analog to digital converter, and optionally, a protective sheath; wherein the smart thermal sensor converts the measured temperature from an analog thermal signal to a digital thermal signal prior to transmission of the thermal signal to the communication bus.
Aspect 15—The method according to any of Aspects 13 or 14, wherein the gas combustion engine is a gas turbine engine or a gas piston engine with the plurality of combustion zones ranging from 2 to 18.
Aspect 16—The method according to any of Aspects 13-15, wherein the control unit is an electronic control unit (ECU), an electronic engine control (EEC) unit, or a full authority digital engine controller (FADEC).
Aspect 17—The method according to any of Aspects 13-16, wherein the control unit identifies a failure with one or more of the thermal sensors.
Aspect 18—The method according to any of Aspects 13-16, wherein the gas combustion engine further comprises a plurality of fuel injectors, such that fuel flows through at least one fuel injector into each of the combustion zones. The control unit decreases the flow of fuel through one or more of the fuel injectors into at least one combustion zone when the control unit determines the temperature in that at least one combustion zone is higher than the temperatures measured for the other combustion zones. The control unit increases the flow of fluid through one or more of the fuel injectors into at least one combustion zone when the control unit determines the temperature in that at least one combustion zone is lower than the temperatures measured for the other combustion zones.
Aspect 19—The use of a temperature control system comprising a plurality of smart thermal sensors integrated with a gas combustion engine having a plurality of combustion zones according to any of Aspects 1-12; wherein measured thermal signals are used to adjust one or more operating parameters of the gas combustion engine.
Aspect 20—The use of a temperature control system comprising a plurality of smart thermal sensors integrated with a gas combustion engine having a plurality of combustion zones according to the method of any of Aspects 13-18.
The foregoing description of various forms of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Numerous modifications or variations are possible in light of the above teachings. The forms discussed were chosen and described to provide the best illustration of the principles of the invention and its practical application in order to enable one of ordinary skill in the art to utilize the invention in various forms and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.
