Thermal management system

In one embodiment a gas turbine engine is disclosed having a heat exchanger at least partially disposed in a bypass duct. In one form the gas turbine engine is a high bypass ratio engine. The heat exchanger may be coupled with a directed energy weapon to provide coolant flow and regulate the temperature of the directed energy weapon. Other devices may also be coupled with the heat exchanger, either as an alternative to in addition to the directed energy weapon.

TECHNICAL FIELD

The present application generally relates to heat exchange systems, and more particularly, but not exclusively, to gas turbine integrated heat exchangers.

BACKGROUND

Effective heat transfer remains an area of significant interest for heat producing components used in conjunction with gas turbine engine energy production and/or propulsion. Some existing systems have certain shortcomings. Accordingly, there remains a need for further contributions in this area of technology.

SUMMARY

One embodiment of the present application is a unique heat transfer technique for a gas turbine engine. Other embodiments include unique apparatus, systems, devices, hardware, and methods for heat transfer systems. Further embodiments, forms, objects, features, advantages, aspects, and benefits of the present invention shall become apparent from the following description and drawings.

DETAILED DESCRIPTION

FIG. 1illustrates a gas turbine engine50having a heat exchange system55that embodies one form of the present invention. The gas turbine engine50provides energy as part of an electrical generator set in some forms, and/or in other forms may provide power to an aircraft. As used herein, the term “aircraft” includes, but is not limited to, helicopters, airplanes, unmanned space vehicles, fixed wing vehicles, variable wing vehicles, rotary wing vehicles, hover crafts, and other airborne and/or extraterrestrial vehicles. Further, the present inventions are contemplated for utilization in other applications that may not be coupled with an aircraft such as, for example, industrial applications, power generation, pumping sets, naval propulsion weapons systems, security systems, perimeter defense/security systems, and the like known to one of ordinary skill in the art.

The gas turbine engine50operates by receiving working fluid through an inlet60of the gas turbine engine50and discharging working fluid through an outlet65, which typically includes combustion exhaust gases and air. The working fluid entering through inlet60is typically air. The gas turbine engine of the illustrative embodiment is a turbofan engine that includes a fan70, a compressor75, a combustor80, and a turbine85. In other embodiments, however, the gas turbine engine50may take on other forms, such as, but not limited to, turboprop, turbojet, etc. Airflow entering the inlet60of the gas turbine engine50is accelerated and compressed by the fan70which produces a fan flow stream95. The fan flow stream is split and becomes a core flow100and a bypass flow105. The core flow100flows from the fan70and through the compressor75, the combustor80, and the turbine85before exiting at the outlet65of the gas turbine engine50. As airflow traverses gas turbine engine50the core flow100it is expanded through the turbine85thereby creating mechanical work to drive the fan70and the compressor75. The bypass flow105traverses from the fan70through a bypass duct115thereby bypassing the core of the gas turbine engine50before exhausting at the outlet65. The bypass flow105can be created by any type of bladed rotor operable to increase the pressure of the airflow, whether the bladed rotor is a fan70as depicted in the illustrative embodiment, or a compressor as depicted further below. Airflow flowing through any of the flow paths may be used to provide thrust for an aircraft and/or cooling for a relatively high temperature component, to set forth just two non-limiting examples. Suitable flow paths include the core flow path, the bypass flow path, or any other flow path provided by the gas turbine engine.

The heat exchange system55is incorporated with the gas turbine engine50, and in one form includes an ejector120and a heat exchanger125. In some applications, the gas turbine engine50may be an existing gen-set or aircraft power plant which is retrofitted to include the heat exchange system55. The heat exchange system55is used to transfer heat from at least one portion of a heat producing component into a media at cooler temperatures. In one non-limiting example, the heat producing component is a directed energy weapon. The heat exchange system55may be configured to operate at a variety of temperatures and pressures. To set forth just a few non-limiting examples, the heat exchange system55may be used to accommodate different operating conditions or unique needs of different heat producing components.

In one form, the ejector120of the heat exchange system55includes an ejector inlet130, an ejector flow path135, and a mixer140. In one form the ejector inlet130is formed in the inlet60of the gas turbine engine50and is sized to capture an ambient airflow145. In some embodiments, the ejector inlet130is integrally formed in the inlet60of the gas turbine engine50, but in other embodiments the ejector inlet130is a separately formed construction that is added/retrofitted to a pre-existing engine. In still other embodiments, the ejector inlet130is positioned at locations other than the inlet60.

The ejector flow path135extends from the ejector inlet130in the illustrative embodiment and is configured to convey the ambient airflow145to the bypass duct115by means of a fluid pump described below. In one form, the ejector flow path135extends axially from the ejector inlet130and occupies a circumferential area of the inlet60, but in other forms the flow path takes on any variety of configurations. In still other forms, the ejector flow path135occupies substantially the entire circumferential distance around the inlet60, or just a portion thereof.

The mixer140is oriented at the downstream end of the ejector flow path135in the illustrative embodiment, and is configured to intermix the ambient airflow145traversing the ejector flow path135with the fan flow stream95downstream of the fan70. A mixed airflow147, which results from mixing the ambient airflow145with the fan flow stream95, traverses through the bypass duct115. The mixer140may have a variety of configurations useful for mixing the ambient airflow145with the fan flow stream95, including vertical flow generators and swirled lobed mixers, to set forth just two non-limiting examples. In some embodiments, the ejector120includes a mixer140having plain features such as that depicted in the illustrative embodiment. In such embodiments, airflow entrained through ejector may be mixed through shearing action with airflow traversing through the bypass flow path.

In the illustrative embodiment, the heat exchanger125includes a heat exchange member150, an intake manifold155, an exit manifold160, and heat exchanger conduits165and170. In other embodiments, the heat exchanger125may include fewer components or additional components. In one form the heat exchange member150may operate as part of a refrigerant circuit. For example, the heat exchange member150can take the form of a condenser or evaporator, to set forth just two non-limiting examples.

The heat exchange member150is configured to convey a heat exchange fluid185and may do so through a variety of internal passageways (not shown). In one form the heat exchange member150includes at least one surface or portion that is in thermal contact with the bypass duct115of the gas turbine engine50. In one form, the heat exchange member is configured to extend across the bypass duct115from an upstream position in a case side175to a downstream position in a core side180, but other configurations are also contemplated herein. For example, the heat exchanger125can be substantially disposed within either the case side175or the core side180, or can be disposed from a downstream position in the case side175to an upstream position in the core side180. In the illustrative embodiment, the heat exchange member150is configured to convey the heat exchange fluid185from a downstream position at the intake manifold155to an upstream position at the exit manifold160. In other embodiments, however, the heat exchange fluid185flows from an upstream position to a downstream position. In still further embodiments, the heat exchange member150is a passive heat exchanger such that the heat exchange fluid185may not be needed.

In one form of operation, heat is transferred from a relatively high temperature heat exchange fluid185to the mixed airflow147. Heat exchange rates will generally vary depending on the relative temperature difference between the heat exchange fluid185and the mixed airflow147, the flow rates of the heat exchange fluid185and the mixed airflow147, as well as the outer geometry of the heat exchanger125, to mention just a few variables that may affect heating exchange rates. In one embodiment the heat exchange member150includes radiator fins or other similar device(s) to provide higher heat transfer rates. As referred to above, in some embodiments, the heat exchange member is a solid heat sink that is in thermal contact with a heat producing component, thus eliminating the need to circulate the heat exchange fluid185.

In one form the intake manifold155is used to receive the heat exchange fluid185returning from a heat producing component through the heat exchanger conduit165, and thereafter deliver the heat exchange fluid185to the heat exchange member150. The intake manifold155can be configured to accept one stream or multiple streams of the heat exchange fluid from multiple heat exchange components. In some embodiments, the heat exchanger125does not include intake manifold155, rather, the heat exchange fluid185returning from a heat producing component flows directly into the heat exchange member150.

The exit manifold160may be configured to receive a relatively cool heat exchange fluid185and distribute it to a heat producing component. The exit manifold160may be configured to return the heat exchange fluid to one or multiple heat producing components. In some embodiments, the heat exchanger125does not include the exit manifold160, rather, the heat exchange fluid185flows directly from the heat exchange member150to a heat producing component.

The heat exchanger conduits165and170are configured to convey the heat exchange fluid185to and from a heat producing component (not shown). The heat exchanger conduits165and170may include single or multiple conduits. In some non-limiting forms, the multiple conduits may be routed to and from multiple heat producing components, the conduits may be used to deliver the heat exchange fluid to multiple locations within a single heat producing component, or may be used in any other type of distraction scheme, or any type of a combination. In other embodiments, the heat exchanger conduits165and/or170have sectors that correspond to different sources and/or destinations of the heat exchange fluid185. In one non-limiting example, multiple conduits are combined to form a single sectorized conduit.

One implementation of the present application includes a heat exchange fluid that is used to cool a heat producing component, such as a directed energy weapon system that is coupled to a gas turbine engine. The heat exchange fluid flows from a relatively high temperature heat exchange component, through a heat exchange conduit, and into a heat exchange member which is exposed to an airflow at a relatively cool temperature. The airflow can include ambient air and fan bypass air and preferably is at a lower temperature than the heat exchange fluid. The ambient air or other suitable air source can be entrained with the fan bypass air through the action of a fluid pump in the form of an ejector formed in the inlet of the gas turbine engine. Once the heat exchange fluid has been cooled by the heat exchange member, it is returned to the relatively high temperature heat producing component.

Referring toFIG. 2, another embodiment of the present invention is depicted. A turbojet engine190in the illustrative embodiment includes the heat exchange system55and a compressed air pathway187. The compressed air pathway187extends from a core flow path189to the bypass duct115and is configured to supply a compressed airflow at relatively high velocity. An ejector may be formed when the compressed airflow enters the bypass duct115, thereby pumping the ambient airflow145into the bypass duct115to create the mixed airflow147. The mixer140may be configured to mix the ambient airflow145with airflow from the compressed air pathway187. Although engine190is depicted as a turbojet, other types of gas turbine engines having a compressed air pathway187are also contemplated herein.

For this illustrative embodiment, the heat exchanger125includes the heat exchange member150, the intake manifold155, the exit manifold160, and the heat exchanger conduits165and170, but other embodiments may include fewer or additional components. The heat exchange member150at least partially resides in the bypass duct115of the turbojet engine190and in one form is configured with heat exchange sectors195,200, and205. In one form the heat exchange sectors195,200, and205provide independent conduits through which the heat exchange fluid185may flow. The heat exchange fluid185may flow in the same direction across the heat exchange sectors195,200, and205, or may flow in opposite directions. The heat exchange sectors195,200, and205may be defined by conduit walls210and215or any other sector-forming structure. In some applications, the conduit walls210and215may extend only partially along the length of the heat exchange member150thus allowing the heat exchange fluid185to intermix before exiting the heat exchanger125.

In one form the intake manifold155is used to receive the heat exchange fluid185returning from a heat producing component through the heat exchanger conduit165, and thereafter deliver the heat exchange fluid185to the heat exchange member150. The intake manifold155can be configured to accept and separately maintain multiple streams of the heat exchange fluid from multiple heat exchange components. In some embodiments, the heat exchanger125does not include the intake manifold155, rather, the heat exchange fluid185returning from one or more heat producing components flows directly into the heat exchange member150and into an independent heat exchange sector.

The exit manifold160may be configured to receive a relatively cool heat exchange fluid185and distribute it to a heat producing component. The exit manifold160may be configured to return the heat exchange fluid to multiple heat producing components. In other embodiments, the heat exchanger125does not include the exit manifold160, rather, the heat exchange fluid185flows directly from the heat exchange member150to a heat producing component.

The heat exchanger conduits165and170are configured to convey the heat exchange fluid185to and from a heat producing component (not shown). The heat exchanger conduits165and170may include multiple conduits. In some non-limiting forms, the multiple conduits may be routed to and from multiple heat producing components, the conduits may be used to deliver the heat exchange fluid to multiple locations within a single heat producing component, or may be used in any other type of distraction scheme, or any type of a combination. In other embodiments, the heat exchanger conduits165and/or170have sectors that correspond to different sources and/or destinations of the heat exchange fluid185. In one non-limiting example, multiple conduits are combined to form a single sectorized conduit.

Referring toFIG. 3, the gas turbine engine50is shown coupled to a directed energy weapon220through the heat exchanger125and a power conduit225. The directed energy weapon220may also be referred to as a radiant energy generating device. In one form the directed energy weapon220may convert the electricity input from a source into a radiant electromagnetic energy output that can be directed to a target. In some applications the directed energy weapon220may generate a directed, radiant, electromagnetic energy output in the microwave range. In still other forms, the directed energy weapon may be based on a form of laser, such as a free electron laser, that may extend from the microwave regime to the visible light spectrum; a combination of different radiant energy generators; and/or a different type of high-level electromagnetic energy generator suitable for a variety of operations. In some forms the directed energy weapon220may be replaced with any variety of other components that may be provided with power and/or heat exchange capabilities. Such components may include high power electronics, among other possibilities. In some forms, the gas turbine engine50may be strictly used to provide electrical power and heat transfer to the directed energy weapon220, thus requiring another source of propulsion if the directed energy weapon220is installed on a moving platform such as an aircraft. In other forms, however, the directed energy weapon220may be installed on an aircraft powered by the gas turbine engine50that provides both propulsion and heat transfer. For example, the directed energy weapon220may be installed on a watercraft, such as a naval vessel, to provide perimeter defense, in which the gas turbine engine provides both propulsion for the vessel as well as electrical power and heat dissipation.

The power conduit225may be used to provide power to the directed energy weapon220. The direction of the arrow indicates that the gas turbine engine50provides such power to the directed energy weapon220. The gas turbine engine50may provide any form of useful energy such as, but not limited to, mechanical, thermal, and/or electrical. In some forms, the gas turbine engine50may receive power from the directed energy weapon or other devices.

The heat exchanger125is shown having a double arrowhead which indicates the recirculating nature of the heat exchange fluid (not shown). For example, a relatively high temperature heat exchange fluid may be circulated from the directed energy weapon220through the heat exchanger125to lower the temperature of the heat exchange fluid before it is returned to the directed energy weapon220to absorb additional heat. Though the heat exchanger125is depicted having two arrowheads, it will be appreciated that the heat exchanger125may take the form of a solid heat sink in which case it may not include a recirculating heat exchange fluid.

FIG. 4depicts a multi-sector heat exchanger. The gas turbine engine50is shown coupled to a component235through a multi-sector heat exchanger237. Fluid flow direction arrows240,245, and250indicate that the fluid disposed within the multi-sector heat exchanger237may flow in different directions and that the multi-sector heat exchanger237may comprise separate compartments for each of those directions240,245, and250. Though only one component235is depicted inFIG. 4, other components may be added in other embodiments.

One embodiment of the present invention is a heat exchanger integrated with a gas turbine engine, with the heat exchanger disposed in a bypass duct of the engine. A heat exchange fluid within the heat exchanger circulates between the heat exchanger and a heat producing component, such as, but not limited to, a directed energy weapon system.

One form of the present invention provides a gas turbine engine including a bladed rotor to receive air from an inlet, the bladed rotor being in fluid communication with a duct to supply a compressed air flow downstream of the inlet, an ejector operable to provide an ambient air flow to the duct, a first ejector stream of the ejector including the compressed air flow, and a second ejector stream of the ejector including the ambient air flow, a mixer to mix the ambient air flow and the compressed air flow together to provide a mixed air flow downstream of the inlet, and a heat exchanger located in the duct to transfer heat between the heat exchanger and the mixed air flow, the heat exchanger located downstream of the mixer.

Another form of the present invention provides a directed energy weapon including at least one heat producing component, a gas turbine engine having a duct operable to convey air, and a heat exchanger located in the duct and thermodynamically coupled with the gas turbine engine and the directed energy weapon to exchange heat with a flow stream of the gas turbine engine, the heat exchanger located in the duct.

Yet another form of the present invention provides a gas turbine engine having a bypass duct downstream of a compressor fan, a heat producing component, an ejector having a first fluid flow path through the bypass duct and a second fluid flow path, and means for ejector cooling the heat producing component.

Yet a further form of the present invention provides a method including rotating a bladed rotor, flowing a bypass flow stream downstream of the bladed rotor, pumping cooling air by an ejector action using the bypass flow stream, mixing the cooling air and the bypass flow stream to create a mixed stream, and exchanging heat between a heat exchanger and the mixed stream.