Patent Publication Number: US-2022236013-A1

Title: Heat exchange system

Description:
FIELD 
     The present disclosure relates to a heat exchange system, such as a heat exchange system for a gas turbine engine. 
     BACKGROUND 
     Typical aircraft propulsion systems include one or more gas turbine engines. The gas turbine engines generally include a turbomachine, the turbomachine including, in serial flow order, a compressor section, a combustion section, a turbine section, and an exhaust section. In operation, air is provided to an inlet of the compressor section where one or more axial compressors progressively compress the air until it reaches the combustion section. Fuel is mixed with the compressed air and burned within the combustion section to provide combustion gases. The combustion gases are routed from the combustion section to the turbine section. The flow of combustion gasses through the turbine section drives the turbine section and is then routed through the exhaust section, e.g., to atmosphere. 
     Certain operations and systems of the gas turbine engine and aircraft may generate a relatively large amount of heat. Fuel has been determined to be an efficient heat sink to receive at least some of such heat during operations due at least in part to its heat capacity and an increased efficiency in combustion operations that may result from combusting higher temperature fuel. Other fluids have been determined to be efficient heat sinks to receive at least some of such heat during operations of the gas turbine engine. The inventors of the present disclosure have come up with various configurations and devices to improve on currently known heat exchange systems. 
     BRIEF DESCRIPTION 
     Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention. 
     In one exemplary embodiment of the present disclosure, a heat exchange system for a gas turbine engine is provided. The heat exchange system includes a first heat exchanger that defines a first heat source flowpath, a second heat exchanger that defines a second heat source flowpath, and a coolant fluid circuit. The coolant fluid circuit defines a first coolant flowpath that extends through the first heat exchanger and is in thermal communication with the first heat source flowpath, and a second coolant flowpath that extends through the second heat exchanger and is in thermal communication with the second heat source flowpath. The first coolant flowpath and the second coolant flowpath are arranged in a parallel flow configuration. 
     In another exemplary embodiment of the present disclosure, a gas turbine engine having a compressor section, a combustion section, and a turbine section is provided. The gas turbine system includes a first heat generating component, a second heat generating component, and a heat exchange system. The heat exchange system includes a first heat exchanger that defines a first heat source flowpath, a second heat exchanger that defines a second heat source flowpath, and a coolant fluid circuit. The coolant fluid circuit defines a first coolant flowpath that extends through the first heat exchanger and is in thermal communication with the first heat source flowpath, and a second coolant flowpath that extends through the second heat exchanger and is in thermal communication with the second heat source flowpath. The first coolant flowpath and the second coolant flowpath are arranged in a parallel flow configuration. 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: 
         FIG. 1  is a cross-sectional view of a gas turbine engine in accordance with an exemplary aspect of the present disclosure. 
         FIG. 2  is a schematic view of a heat exchange system in accordance with an exemplary aspect of the present disclosure. 
         FIG. 3  is a schematic view of a heat exchange system in accordance with an exemplary aspect of the present disclosure. 
         FIG. 4  is a schematic view of a heat exchange system in accordance with an exemplary aspect of the present disclosure. 
         FIG. 5  is a schematic view of a heat exchange system in accordance with an exemplary aspect of the present disclosure. 
         FIG. 6  is a perspective view of a diverter in accordance with an exemplary aspect of the present disclosure. 
         FIG. 7  is a perspective view of a drum of the diverter of  FIG. 6  in accordance with an exemplary aspect of the present disclosure. 
         FIG. 8  is a cross-sectional, top-view of the diverter of  FIG. 6  in accordance with an exemplary aspect of the present disclosure. 
         FIGS. 9A-9C  are perspective views of different operational modes of the diverter of  FIG. 6  in accordance with an exemplary aspect of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to present embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the invention. 
     The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations. Additionally, unless specifically identified otherwise, all embodiments described herein should be considered exemplary. 
     As used herein, the terms “first”, “second”, and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. 
     The terms “forward” and “aft” refer to relative positions within a gas turbine engine or vehicle, and refer to the normal operational attitude of the gas turbine engine or vehicle. For example, with regard to a gas turbine engine, forward refers to a position closer to an engine inlet and aft refers to a position closer to an engine nozzle or exhaust. 
     The terms “upstream” and “downstream” refer to the relative direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the direction from which the fluid flows, and “downstream” refers to the direction to which the fluid flows. 
     The term “fluid” may be a gas or a liquid. The term “fluid communication” means that a fluid is capable of making the connection between the areas specified. 
     The term “thermal communication” means that heat is capable of being transferred between the areas specified. 
     The terms “coupled,” “fixed,” “attached to,” and the like refer to both direct coupling, fixing, or attaching, as well as indirect coupling, fixing, or attaching through one or more intermediate components or features, unless otherwise specified herein. 
     The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. 
     Approximating language, as used herein throughout the specification and claims, is applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about”, “approximately”, and “substantially”, are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value, or the precision of the methods or machines for constructing or manufacturing the components and/or systems. For example, the approximating language may refer to being within a 1, 2, 4, 10, 15, or 20 percent margin. These approximating margins may apply to a single value, either or both endpoints defining numerical ranges, and/or the margin for ranges between endpoints. 
     Here and throughout the specification and claims, range limitations are combined and interchanged, such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. 
     In accordance with one or more embodiments described herein, a gas turbine engine can be equipped with one or more heat exchange systems. The heat exchange system can be provided to cool certain systems of the gas turbine engine or of the aircraft that the gas turbine engine is installed upon. For example, the heat exchange system can be provided to cool one or more heat generating components, such as a gearbox, a bearing, a pump, a fan blade pitch change mechanism, or a motor-generator, to name a few. The heat exchange system can cool these components by cooling a relatively hot fluid, such as a lubricant that is delivered to those components, with a cooler fluid, such as fuel. When fuel is used as a coolant fluid, instead of other coolant fluids such as supercritical fluids, dielectric fluids, air, or synthetic heat transfer fluids, the heat exchange system can have the additional benefit of heating the fuel. Heating the fuel of a gas turbine engine can increase the efficiency of the engine by reducing the amount of fuel needed to achieve desired combustor firing temperatures. Additionally, heating the fuel can improve the power output of the gas turbine engine. 
     In at least one embodiment, the heat exchange system includes a coolant fluid circuit that has a first coolant flowpath that extends through a first heat exchanger and a second coolant flowpath that extends through a second heat exchanger. Each of the coolant flowpaths can cool a relatively hot fluid that is flowing through a heat source flowpath that flows through its respective heat exchanger. The first and second coolant flowpaths can be arranged in a parallel flow configuration, instead of in a series flow configuration. As will be appreciated from the discussion herein, arranging the coolant flowpaths in a parallel flow configuration can minimize the pressure drop of the coolant fluid circuit. Additionally, when fuel is used as a coolant fluid circuit, arranging the coolant flowpaths in a parallel flow configuration can reduce the reaction time of the engine. 
     The heat exchange system may further include a plurality of valves or a diverter that can selectively provide at least a portion of the flow to one or more of the coolant flowpaths and/or to a bypass flowpath. As will be explained in greater detail, including a diverter or a plurality of valves, instead of a single two-way valve or no valves, can allow for the optimization of the amount of coolant flow provided to each of the heat exchangers and/or to the bypass flowpath. Allowing the optimization of the coolant flow can allow for a maximum amount of coolant fluid to be provided to the bypass flowpath, and a minimum amount of coolant fluid to be provided to the coolant flowpaths. Allowing only a minimum amount of coolant fluid to be provided to the coolant flowpaths reduces the amount of flow that passes through fluid-restricting devices, such as heat exchangers, which can result in a pressure loss of the coolant fluid circuit. When fuel is used as the coolant fluid, reducing pressure loss can increase the efficiency or power output of the gas turbine engine. When fuel is used as a coolant fluid, maximizing the amount of fuel delivered to the bypass flowpath can reduce the reaction time of the engine. 
     In at least one embodiment, components of the heat exchange system are arranged in close proximity to each other and/or as a unitary component, instead of arranged separately and/or far apart from each other. When the components of the heat exchange system are arranged in close proximity to each other and/or as a unitary component, heat can be transferred between the components, through the conductive material that is nearby. In this way, one or more of the heat source flowpaths can be further cooled by the conductive material that surrounds them, via induction. 
     Systems are described herein that extend beyond the claimed heat exchange system. It will be appreciated that these systems are provided by way of example only, and the claimed systems are not limited to applications using or otherwise incorporated with these other systems. The disclosure is not intended to be limiting. For example, it should be understood that one or more embodiments described herein may be configured to operate independently or in combination with other embodiments described herein. 
     Referring now to the drawings, wherein identical numerals indicate the same elements throughout the figures,  FIG. 1  is a schematic cross-sectional view of a gas turbine engine in accordance with an exemplary embodiment of the present disclosure. More particularly, for the embodiment of  FIG. 1 , the gas turbine engine is a high-bypass turbofan jet engine, referred to herein as “turbofan engine  10 .” As shown in  FIG. 1 , the turbofan engine  10  defines an axial direction A (extending parallel to a longitudinal centerline  12  provided for reference) and a radial direction R. In general, the turbofan  10  includes a fan section  14  and a turbomachine  16  disposed downstream from the fan section  14 . 
     The exemplary turbomachine  16  depicted generally includes a substantially tubular outer casing  18  that defines an annular inlet  20 . The outer casing  18  encases, in serial flow relationship, a compressor section including a booster or low pressure (LP) compressor  22  and a high pressure (HP) compressor  24 ; a combustion section  26 ; a turbine section including a high pressure (HP) turbine  28  and a low pressure (LP) turbine  30 ; and a jet exhaust nozzle section  32 . A high pressure (HP) shaft or spool  34  drivingly connects the HP turbine  28  to the HP compressor  24 . A low pressure (LP) shaft or spool  36  drivingly connects the LP turbine  30  to the LP compressor  22 . The compressor section, combustion section  26 , turbine section, and nozzle section  32  together define a core air flowpath  37 . 
     For the embodiment depicted, the fan section  14  includes a fan  38  having a plurality of fan blades  40  coupled to a rotor disk  42  in a spaced apart manner. As depicted, the fan blades  40  extend outwardly from rotor disk  42  generally along the radial direction R. The disk  42  is covered by rotatable front hub  48  aerodynamically contoured to promote an airflow through the plurality of fan blades  40 . Additionally, the exemplary fan section  14  includes an annular fan casing or outer nacelle  50  that circumferentially surrounds the fan  38  and/or at least a portion of the turbomachine  16 . It should be appreciated that the nacelle  50  may be configured to be supported relative to the core  16  by a plurality of circumferentially-spaced outlet guide vanes  52 . Moreover, a downstream section  54  of the nacelle  50  may extend over an outer portion of the turbomachine  16  so as to define a bypass airflow passage  56  therebetween. 
     During operation of the turbofan engine  10 , a volume of air  58  enters the turbofan  10  through an associated inlet  60  of the nacelle  50  and/or fan section  14 . As the volume of air  58  passes across the fan blades  40 , a first portion of the air  58  as indicated by arrows  62  is directed or routed into the bypass airflow passage  56  and a second portion of the air  58  as indicated by arrow  64  is directed or routed into the core air flowpath  37 , or more specifically into the LP compressor  22 . The ratio between the first portion of air  62  and the second portion of air  64  is commonly known as a bypass ratio. The pressure of the second portion of air  64  is then increased as it is routed through the HP compressor  24  and into the combustion section  26 , where it is mixed with fuel and burned to provide combustion gases  66 . 
     The combustion gases  66  are routed through the HP turbine  28  where a portion of thermal and/or kinetic energy from the combustion gases  66  is extracted via sequential stages of HP turbine stator vanes  68  that are coupled to the outer casing  18  and HP turbine rotor blades  70  that are coupled to the HP shaft or spool  34 , thus causing the HP shaft or spool  34  to rotate, thereby supporting operation of the HP compressor  24 . The combustion gases  66  are then routed through the LP turbine  30  where a second portion of thermal and kinetic energy is extracted from the combustion gases  66  via sequential stages of LP turbine stator vanes  72  that are coupled to the outer casing  18  and LP turbine rotor blades  74  that are coupled to the LP shaft or spool  36 , thus causing the LP shaft or spool  36  to rotate, thereby supporting operation of the LP compressor  22  and/or rotation of the fan  38 . 
     The combustion gases  66  are subsequently routed through the jet exhaust nozzle section  32  of the turbomachine  16  to provide propulsive thrust. Simultaneously, the pressure of the first portion of air  62  is substantially increased as the first portion of air  62  is routed through the bypass airflow passage  56  before it is exhausted from a fan  38  nozzle exhaust section  76  of the turbofan  10 , also providing propulsive thrust. The HP turbine  28 , the LP turbine  30 , and the jet exhaust nozzle section  32  at least partially define a hot gas path  78  for routing the combustion gases  66  through the turbomachine  16 . 
     It should be appreciated, however, that the exemplary turbofan engine  10  depicted in  FIG. 1  is by way of example only, and that in other exemplary embodiments, the turbofan engine  10  may have any other suitable configuration. For example, in other exemplary embodiments, the fan  38  may be configured as a variable pitch fan including, e.g., a suitable actuation assembly for rotating the plurality of fan blades about respective pitch axes, the turbofan engine  10  may be configured as a geared turbofan engine having a reduction gearbox between the LP shaft  36  and fan section  14 , etc. It should also be appreciated, that in still other exemplary embodiments, aspects of the present disclosure may be incorporated into any other suitable gas turbine engine. For example, in other exemplary embodiments, aspects of the present disclosure may be incorporated into, e.g., turboprop engine. 
     Referring now to  FIG. 2 , a schematic view of a heat exchange system  100  in accordance with an exemplary embodiment of the present disclosure is shown. The heat exchange system  100  includes a plurality of heat exchangers  122   a - c , a plurality of heat source flowpaths  120   a - c , each extending through a heat exchanger  122 , and a coolant fluid circuit  110 . The coolant fluid circuit  110  includes a plurality of coolant flowpaths  115   a - c , each extending through a heat exchanger  122   a - c . For the embodiment shown, the coolant fluid circuit  110  includes a bypass flowpath  117  that does not extend through a heat exchanger  122 . 
     The coolant fluid that flows through the coolant fluid circuit  110  can be any fluid that can transfer heat between the heat source flowpaths  120  and the coolant flowpaths  115 . For example, the coolant fluid can be a fuel, a dielectric fluid, air, or a heat transfer fluid such as DOWTHERM or THERMINOL. 
     The coolant flowpaths  115  of the coolant fluid circuit  110  and the heat exchangers  122  are arranged in a parallel flow configuration. Each of the coolant flowpaths  115  have a common inlet of a flow of fluid, which is the input  111  to the coolant fluid circuit  110 , and have a common outlet of the flow of fluid, which is the output  119  of the coolant fluid circuit  110 . Additionally, the coolant flowing from the input  111  branches off into multiple coolant flowpaths  115  and then into respective heat exchangers  122 . The parallel configuration may allow the flow of coolant through each coolant flowpath  115  to be independently adjusted or discontinued while the flow of coolant fluid continues through one or more of the other coolant flowpaths  115 . 
     The bypass flowpath  117  can also be arranged in a parallel flow configuration with the coolant flowpaths  115  such that the bypass flowpath  117  has a common source of a flow of fluid with the coolant flowpaths  115  and a common outlet of the flow of fluid with the coolant flowpaths  115 . 
     Each of the heat source flowpaths  120  can be a flowpath circuit, such as an oil circuit, and can include a heat generating component  124 . The relatively hot fluid flowing through each of the heat source flowpaths  120  can be provided to the respective heat generating component  124 . The heat generating component  124  can be a gearbox, a bearing, a pump, a fan blade pitch change mechanism, or a motor-generator, to name a few. Additionally, each of the heat source flowpaths  120  are fluidly independent from one another such that they are not in fluid communication. Also, each of the heat source flowpaths  120  are fluidly independent from the coolant fluid circuit  110  such that each of the heat source flowpaths  120  are not in fluid communication with the coolant fluid circuit  110 . 
     In this example, the heat exchange system  100  includes three heat exchangers  122   a - c , three heat source flowpaths  120   a - c , and three coolant flowpaths  115   a - c . However, it should be understood that the heat exchange system  100  can include any number of heat exchangers  122 , heat source flowpaths  120 , and coolant flowpaths  115 . For example, two, four, five, six, or more heat exchangers  122 , heat source flowpaths  120 , and coolant flowpaths  115 . 
     The heat exchange system  100  can include a plurality of valves  113  configured to control a flow of a fluid. For example, each of the valves  113  can control a flow of a coolant fluid, such as fuel, flowing through one of the coolant flowpaths  115  and/or through the bypass flowpath  117 . In this example, coolant flowpaths  115   a  and  115   b  include a valve  113  to regulate an amount of the coolant fluid that is flowing through the respective heat exchanger  122 . Each of the valves  113  can selectively open and close, either partially or fully, to control the amount of the coolant fluid that flows through each of their respective coolant flowpaths  115  and each of the respective heat exchangers  122 . Coolant flowpaths  115   c  does not include a valve  113 ; however, the other valves  113  that are included in the heat exchange system  100  can collectively control the amount of flow flowing through coolant flowpath  115   c . For example, if the valves allow twenty percent of the flow to be provided to each of coolant flowpath  115   a ,  115   b , and bypass flowpath  117 , the remaining flow, which is forty percent of the flow, is provided to coolant flowpath  115   c . It should be understood, however, that in some examples, an additional valve could be provided to directly control the flow provided to coolant flowpath  115   c.    
     Each heat exchanger  122  is configured to cool the relatively hot fluid flowing through the respective heat source flowpath  120  and heat the coolant fluid that is flowing through the respective coolant flowpath  115 . This is accomplished by arranging each heat source flowpath  120  to be in thermal communication with a respective coolant flowpath  115 . More specifically, the portions of the heat source flowpaths  120  that extend through the heat exchangers  122  are arranged to be in thermal communication with a portion of one of the coolant flowpaths  115  that extend through the same heat exchanger  122 . For example, the portion of the first heat source flowpath  120   a  that extends through the first heat exchanger  122   a  is in thermal communication with the portion of the first coolant flowpath  115   a  that extends through the first heat exchanger  122   a.    
     Even though flowpath  120  has been described as a heat source flowpath and flowpaths  115  and circuit  110  have been described as coolant flowpaths and coolant circuits, it should be understood that a configuration is contemplated where the circuit  110  and flowpaths  115  are heat source flowpaths and the flowpaths  120  are coolant source flowpath. For example, flowpaths  115  could be heat source flowpaths and in fluid communication with each other and arranged in a parallel configuration, and the flowpaths  120  could be coolant flowpaths and are arranged in either a parallel or series configuration. 
     Referring now to  FIG. 3 , a schematic view of a heat exchange system  100  in accordance with an exemplary embodiment of the present disclosure is shown. The heat exchange system  100  of  FIG. 3  may be configured in a similar manner as the exemplary heat exchange system  100  described above with reference to  FIG. 2 . For example, the coolant flowpaths  115   a - c  of the coolant fluid circuit  110  in this example are also arranged in a parallel flow configuration. 
     However, for the exemplary embodiment of  FIG. 3 , the heat exchange system  100  includes a diverter  200  that is configured to separate a flow of fluid into two or more branches and can be further configured to discontinue and/or throttle the flow of fluid into each of the two or more branches, such as the coolant flowpaths  115 . For example, the diverter  200  can be a port diverter valve, a rotary multi-port valve, or the segmented diverter of  FIG. 4  or the drum diverter of  FIG. 6 , which will both be explained in more detail, below. 
     The diverter  200  is configured to selectively provide at least a portion of the flow to one or more of the coolant flowpaths  115  and/or the bypass flowpath  117 . In one example, the diverter  200  can provide equal amounts to each of the coolant flowpaths  115  and no flow to the bypass flowpath  117 . In another example, the diverter  200  can provide equal amounts to each of the coolant flowpaths  115  and to the bypass flowpath  117 . In another example, the diverter  200  can provide unequal amounts to two or more of the coolant flowpaths  115  and/or to the bypass flowpath  117 . For example, one of the coolant flowpaths  115  can receive more than one and a half times as much of the flow as another one of the coolant flowpaths  115 , as measured in pounds per square inch (PSIA). For example, one of the coolant flowpaths  115  can receive at least twice as much, such as at least four times as much, such as at least six times as much of the flow as another one of the coolant flowpaths  115 , and up to about ten times as much, such as about eight times as much, such as about six times as much of the flow as another one of the coolant flowpaths  115 . Even though several examples have been provided, it should be understood that many other variations regarding the amount of flow to be diverted to each of the coolant flowpaths  115  and the bypass flowpath  117  are contemplated. 
     Referring now to  FIGS. 4 and 5 , schematic views of heat exchange systems  100  in accordance with additional exemplary embodiments of the present disclosure are shown. Like the examples of  FIGS. 2 and 3 , the coolant flowpaths  115   a - d  of the coolant fluid circuit  110  and the heat exchangers  122   a - d  are arranged in a parallel flow configuration. As such, the heat exchange system  100  may be configured in a similar manner as the exemplary heat exchange systems  100  described above with reference to  FIGS. 2 and 3 . For example, each of the coolant flowpaths  115  have a common inlet of a flow of fluid, which is the input  111  to the coolant fluid circuit  110 , and have a common outlet of the flow of fluid, which is the output  119  of the coolant fluid circuit  110 . Additionally, the coolant flowing from the input  111  branches off into multiple coolant flowpaths  115  and then into respective heat exchangers  122 . The parallel configuration allows the flow of coolant through each coolant flowpath  115  to be independently adjusted or discontinued while the flow of coolant fluid continues through one or more of the other coolant flowpaths  115 . 
     In the example of  FIG. 4 , the heat exchange system  100  does not include a bypass flowpath  117 , whereas the heat exchange system  100  of  FIG. 5  includes a bypass flowpath  117  that is arranged in parallel configuration with the coolant flowpaths  115 . 
     Each of the heat source flowpaths  120  are fluidly independent from the coolant fluid circuit  110  such that each of the heat source flowpaths  120  are not in fluid communication with the coolant fluid circuit  110 . Additionally, each of the heat source flowpaths  120  are fluidly independent from all other heat source flowpaths  120  in the heat exchange system  100  such that none of the heat source flowpaths  120  are in fluid communication with each other. 
     In this example, the heat exchange system  100  includes four heat exchangers  122   a - d , four heat source flowpaths  120   a - d , and four coolant flowpaths  115   a - d . However, it should be understood that the heat exchange system  100  can include any number of heat exchangers  122 , heat source flowpaths  120 , and coolant flowpaths  115 . For example, two, three, five, six, or more heat exchangers  122 , heat source flowpaths  120 , and coolant flowpaths  115 . 
     In some examples, which are not shown, one or more of the coolant flowpaths  115  pass through a plurality of heat exchangers  122 , each of the heat exchangers  122  being associated with a different heat source flowpath  120 . In this way, the heat exchangers  122  are arranged in a series-parallel circuit. 
     The heat exchange system  100  can include a diverter  200  that is configured to separate a flow of fluid into two or more branches and can be further configured to discontinue and/or throttle the flow of fluid into each of the two or more branches, such as the coolant flowpaths  115 . For example, the diverter  200  can be a port diverter valve, a rotary multi-port valve, the drum diverter of  FIG. 6 , which will both be explained in more detail, below, or a segmented diverter, as shown. 
     As shown, the segmented diverter  200  is partitioned into segments  201 . The partitions  202  between the segments  201  can include windows (not shown) that allow the flow of coolant fluid from the input  111  to enter a first segment  201  and then flow to adjacent segments  201 . From each of the segments  201 , the coolant fluid can flow into its respective coolant flowpath  115 . The partitions can include sliding doors (not shown) that can be used to close, either partially or fully, each of the windows to adjust the amount of flow provided to each of the segments  201 . 
     The non-moving portions of the diverter  200  can be coupled, either directly or indirectly, to one or more of the heat exchangers  122 , or can be a unitary component with one or more of the heat exchangers  122 . The diverter  200  can be positioned approximately equidistant from each of the heat exchangers  122  and/or can be arranged in close proximity to each of the heat exchangers  122 . 
     Two or more of the non-moving components of the diverter  200 , the heat exchangers  122 , the coolant flowpaths  115 , and a portion of each of the heat source flowpaths  120  can form a heat transfer unit  300  such that each is in thermal communication with another. The heat transfer unit  300  can be configured as a heatsink to passively transfer heat. The heat transfer unit  300  can include features, such as fins, that increases its surface area that is in contact with a cooler fluid, such as air, that can surround it. 
     Certain components of the heat transfer unit  300  can be in thermal communication with each other via a thermally conductive material  310  extending between the components. In certain exemplary embodiments, the thermally conductive material  310  may be a metal material. The term “between” in this context does not necessarily mean that that the thermally conductive material  310  extends directly from one component to another, in a straight line. Instead, it should be understood that heat could be transferred from one component to another component with a meandering route taken between the two components. 
     In some examples, the first coolant flowpath  115   a  is in thermal communication with the second heat source flowpath  120   b  via the thermally conductive material  310  between the first coolant flowpath  115   a  and the second heat source flowpath  120   b . In some examples, first heat source flowpath  120   a  is in thermal communication with the second heat exchanger  122   b  via the thermally conductive material  310  between the first heat source flowpath  120   a  and the second heat exchanger  122   b . In some examples, the non-moving components of the diverter  200  can be in thermal communication with the heat source flowpaths  120  via the thermally conductive material  310  between the diverter  200  and the heat source flowpaths  120 . Even though several examples have been provided, it should be understood that many combinations of components of heat transfer unit  300  that are in thermal communication with each other are contemplated. 
     The heat transfer unit  300  can be a unitary component. As used herein, the term “unitary component” refers to the aspects of the component being formed together, or integrally fixed to one another. The heat transfer unit  300  may be formed as a unitary, monolithic component by manufacturing the heat transfer unit  300  with an additive manufacturing process. In another example, the heat transfer unit  300  is an assembly and portions of the heat transfer unit  300  are coupled together such that the portions are in thermal communication with each other. Those portions can be additively manufactured or manufactured with other conventional methods, such as machining the portions from a casting, forging, or bar stock. Either way, the thermally conductive material  310  between each of the heat exchangers  122  and/or heat source flowpaths  120  can draw heat from the heat exchangers  122  and/or the heat source flowpaths  120  to cool the heat transfer unit  300  via induction. Notably, even when coolant fluid is not being provided to one of the coolant flowpaths  115 , the respective heat source flowpath  120  can still be cooled by the metal material that is surrounding the heat source flowpath  120 , via induction. 
     In operation, a coolant fluid, such as fuel, enters the heat exchange system  100  through the input  111 . The flow of coolant fluid can be provided to the diverter  200 , which can selectively provide at least a portion of the flow to one or more of the coolant flowpaths  115  ( FIG. 4  and  FIG. 5 ) and/or to the bypass flowpath  117  ( FIG. 5 ). The flow of coolant fluid can then flow through the heat exchangers  122  where it absorbs heat from the respective heat source flowpath  120 , and then flows toward the output  119  where it exits the heat exchange system  100 . 
     In one example, the first heat generating component  124   a  is an engine lubrication system that is used to lubricate bearings, the second heat generating component  124   b  is a fan pitch change mechanism, the third heat generating component  124   c  is a fan gearbox, and the fourth heat generating component  124   d  is an embedded motor generator. In this example, the diverter  200  can provide approximately 40%, such as between 30% to 50%, of the flow of coolant fluid to the first coolant flowpath  115   a , and approximately 20%, such as between 10% to 30%, of the flow of coolant fluid to each of the second, third, and fourth coolant flowpath  115 . 
     In other examples, there are three heat exchangers  122 , three heat source flowpaths  120 , and three heat generating components  124 . The first heat generating component  124  is an engine lubrication system that is used for bearings, the second heat generating component  124  is a plurality of servos, and the third heat generating component  124  is an embedded motor generator. The diverter  200  can provide approximately 50%, such as between 40% to 60%, of the flow of coolant fluid to the first coolant flowpath  115 , and approximately 25%, such as between 15% to 35%, of the flow of coolant fluid to each of the second and third coolant flowpaths  115 . However, it should be understood that other combinations of ranges are contemplated, and that the distribution of the flow can change over time during operation of the engine. 
     For example, the amount of the flow of coolant fluid that is provided to each of the coolant flowpaths  115  and/or to the bypass flowpath  117  can be selectively adjusted based on one or more engine parameters. One of the engine parameters can be a temperature of one or more heat generating components  124 . When it is determined that the temperature of the heat generating component  124  exceeds a threshold or calculated value, the diverter  200  can increase the amount of the flow of coolant fluid to be provided to the respective coolant flowpath  115 . When it is determined that the temperature of the heat generating component  124  is less than a threshold or calculated value, the diverter  200  can decrease the amount of the flow of coolant fluid to be provided to the respective coolant flowpath  115 . 
     One of the engine parameters can be the ratio of the amount of coolant fluid flowing through a heat exchanger  122  versus the amount of hot fluid flowing through the same heat exchanger  122 . When the amount of coolant fluid, such as fuel, flowing through the heat exchanger  122  is much greater than the amount of hot fluid, such as a lubricant, flowing through the heat exchanger  122 , such as a two to one ratio, a three to one ratio, a four to one ratio, the diverter  200  can allow more of the coolant fluid to be provided to the bypass flowpath  117  to reduce the pressure loss of the coolant fluid circuit  110 . 
     One of the engine parameters can be a requested power level of the engine. When an increase to the power level is requested, fuel, a coolant fluid in some examples, can be provided to the bypass flowpath  117 . Diverting more fuel to the bypass flowpath  117  can reduce the reaction time of the engine when an increase to the power level is requested. More specifically, when the throttle is moved to request more power output, additional fuel is supplied to the combustor of the engine. The fuel can be provided to the combustor quicker if it has a shorter flowpath to travel. As such, fuel that travels through the bypass flowpath  117  can be supplied to the combustor quicker than fuel that travels through one or more heat exchangers  122 . Therefore, providing fuel to the bypass flowpath  117  reduces the reaction time of the engine when an increase to the power level is requested. 
     One of the engine parameters can be the current phase of flight that the aircraft is currently in. In some examples, when the aircraft that the engine is installed on is in flight, one heat generating component  124  may require more cooling, whereas another heat generating component  124  may require less cooling. Conversely, when the aircraft is on the ground, the cooling needs may be swapped. For example, a lubrication system for a propellor gearbox may require less cooling while the aircraft is in flight due to the ambient air in the flowpath being colder, whereas the lubrication system for an accessory gearbox or bearing system may require more cooling while the aircraft is in flight. 
     One of the engine parameters can be the current fuel consumption of the engine. For example, current fuel consumption is typically measured in gallons per hour (GPH) and is lowest when an aircraft is taxing or idling on the ground and the highest when the aircraft is taking-off or ascending. When the fuel consumption is low, less coolant fluid can be provided to the bypass flowpath  117 , whereas more coolant fluid, as a percentage of total flow, can be provided to one or more of the coolant flowpaths  115 . For example, when the fuel consumption is low, such as during taxing or idling on the ground, none of the flow of coolant fluid can be provided to the bypass flowpath or a small percentage, such as up to five percent, such as up to ten percent, of the coolant fluid can be provided to the bypass flowpath  117 . The remaining amount of the flow of coolant fluid can be provided to the coolant flowpaths  115  and distributed to each based on other engine parameters, such as a desired temperature of the fluid flowing through the respective heat source flowpath  120 . 
     In some examples, the amount of the flow of coolant fluid to be provided to the coolant flowpaths  115 , and to the heat exchangers  122 , can be optimized such that a minimal amount of coolant fluid is provided to each of the coolant flowpaths  115 , the remainder of the coolant fluid is provided to the bypass flowpath  117 . This allows a maximum amount of the flow of coolant fluid to be provided to the bypass flowpath  117  and not pass through any flow-restricting devices, such as heat exchangers  122 , which can result in pressure loss. Bypassing a maximum amount of the flow of coolant fluid reduces the pressure loss experienced from the input  111  of the coolant fluid circuit  110  to the output  119  of the coolant fluid circuit  110 , and also reduces the reaction time of the engine when additional power output is requested. 
     Referring now to  FIG. 6 , a perspective view of a diverter  200  in accordance with an exemplary embodiment of the present disclosure is shown. The diverter  200  in this example includes a drum  210  and branch housings  220 . Each of the branch housings  220  can correspond to a coolant flowpath  115 . As best seen in  FIG. 7 , the drum  210  includes one or more windows  215 . The drum  210  can be configured to rotate on an axis such that one or more of the windows  215  align, either partially or fully, with a respective inlet  222  of a branch housing  220 . Each branch housing  220  can further include one or more openings  224  that can align with one or more openings of a heat exchanger  122 . As will be explained in more detail below, one or more, or all, of the openings  224  can be an outlet  226  for the coolant flowpath  115 . The remaining openings  224 , if any, can be inlets or outlets for the heat source flowpath  120 . 
     Referring now to  FIG. 8 , a top view of the diverter  200  of  FIG. 6  in accordance with an exemplary embodiment of the present disclosure is shown. In operation, coolant fluid can flow from the input  111  of the coolant fluid circuit  110  to the drum  210  of the diverter  200 . In this example, the coolant fluid enters the top of the drum  210 . From the drum  210 , the fluid can enter through one or more of the branch housing inlets  222  when the windows  215  are aligned, either partially or fully, with the respective branch housing inlets  222 . From the branch housing inlet  222 , the coolant fluid can flow through the branch housing  220  until it reaches an outlet  226 . From the outlet  226 , it can enter a respective heat exchanger  122 . 
     One or more of the branch housings  220  can also have an opening that is a heat source inlet  228  and an opening  224  that is a heat source outlet  229 . The relatively hot fluid from the heat source flowpath  120  can flow into the inlet  228 , through the branch housing  220 , and out of the outlet  229 . The portions of the coolant flowpath  115  and the heat source flowpath  120  that extend through the branch housing  220  can be in thermal communication such that the coolant flowpath  115  absorbs heat from the heat source flowpath  120 . In this way, the branch housing  220  can be an extension of the heat exchanger  122  to also cool the relatively hot fluid that is flowing through the heat source flowpath  120 . 
     Referring now to  FIGS. 9A-9C , a perspective view of the diverter  200  of  FIG. 6  in different operational modes can be seen. As previously explained, the drum  210  can be rotated so that the windows  215  of the drum  210  align fully, or partially, with one or more branch housing inlets  222 . When the windows  215  align with a branch housing inlet  222 , coolant fluid is able to enter the respective coolant flowpath  115 . More specifically,  FIG. 9A  shows the drum  210  so that one of the windows  215  is aligned with a first branch housing inlet  222   a , one of the windows  215  is aligned with a second branch housing inlet  222   b , and one of the windows  215  is aligned with a third branch housing inlet  222   c . In this position, because there are only three windows  215  on the drum  210 , a window  215  is not positioned with the fourth branch housing inlet  222   d . Instead, a wall of the drum  210  covers the fourth branch housing inlet  222   d . In this mode, the flow of coolant fluid is restricted from entering the fourth branch housing inlet  222   d , but is allowed to enter the first, second, and third branch housing inlets  222   a,b,c  and their respective coolant flowpath  115   a,b,c . The drum  210  in  FIG. 9B  is rotated counterclockwise by ninety degrees so that the wall of the drum  210  aligns with the third branch housing inlet  222   c  and one of the three windows  215  is each aligned with the first, second, and fourth branch housing inlets  222   a,b,d . In this mode, the flow of coolant fluid is restricted from entering the third branch housing inlet  222   c , but is allowed to enter the first, second, and fourth branch housing inlets  222   a,b,d  and their respective coolant flowpath  115   a,b,d . The drum  210  in  FIG. 9C  is rotated by forty-five degrees such that none of the windows  215  align with any of the branch housing inlets  222 . In this mode, the flow of coolant fluid is restricted from entering any of the branch housing inlets  222   a - d.    
     In lieu of, or in addition to, the drum  210  rotating, sliding doors can be provide that selectively move in an upward and downward direction to control and throttle an amount of coolant fluid that enters each of the branch housing inlets  222 . Additionally, an additional opening or port can be provided in the drum  210  to allow coolant fluid to enter the bypass flowpath  117 . 
     The heat exchange system  100  as described has many benefits. First, by arranging the coolant flowpaths  115  and the heat exchangers  122  in a parallel configuration, instead of in series, the volume of coolant fluid in the heat exchange system  100  is reduced because the length of the path that the coolant fluid takes is reduced. Because some coolant fluids, such as fuel, are compressible and expandable, reducing the amount of coolant fluid within the system results in a reduced reaction time of the engine when an increase of power is requested. 
     Second, by arranging the coolant flowpaths  115  and the heat exchangers  122  in a parallel configuration, instead of in series, a pressure drop of the coolant fluid circuit  110 , from the input  111  to the output  119 , is reduced. Additionally, a bypass flowpath  117  can be provided to minimize the pressure drop from the input  111  to the output  119  of the coolant fluid circuit  110 . 
     Third, by arranging the coolant flowpaths  115  and the heat exchangers  122  in a parallel configuration, instead of in series, flow can be more accurately calculated. Typically, sensors to measure fuel flow, a coolant fluid, are located upstream from the heat exchangers  122 . If the heat exchangers  122  are in a series configuration, more variables exist to calculate the fuel flow into the combustor of the engine, making the calculation more complicated and less reliable. however, arranging the heat exchangers  122  in a parallel configuration removes many of the variables and simplifies the calculation, making it more reliable. 
     Fourth, by arranging the coolant flowpaths  115  and the heat exchangers  122  in a parallel configuration, instead of in series, the flow of coolant fluid that enters each coolant flowpath  115  can be optimized. More specifically, if the heat exchangers  122  were arranged in series, a certain flow of coolant fluid must enter each of the heat exchangers  122 . However, with the parallel configuration, coolant fluid can be selectively diverted and/or throttled for current needs. 
     Fifth, by arranging the heat exchangers  122  in close proximity to each other ( FIG. 4  and  FIG. 5 ) and configured as a heat transfer unit  300 , additional cooling can be realized, by induction, as previously explained. Therefore, even when coolant fluid is not being provided to one of the coolant flowpaths  115 , the respective heat source flowpath  120  can still be cooled by the metallic material that is surrounding the heat source flowpath  120 , via induction. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. 
     The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 
     Further aspects are provided by the subject matter of the following clauses: 
     1. A heat exchange system for a gas turbine engine, the heat exchange system comprising a first heat exchanger defining a first heat source flowpath, a second heat exchanger defining a second heat source flowpath, and a coolant fluid circuit defining a first coolant flowpath extending through the first heat exchanger and in thermal communication with the first heat source flowpath, and a second coolant flowpath extending through the second heat exchanger and in thermal communication with the second heat source flowpath, wherein the first coolant flowpath and the second coolant flowpath are arranged in a parallel flow configuration. 
     2. The heat exchange system of any preceding clause, wherein the heat source flowpaths are fluidly independent. 
     3. The heat exchange system of any preceding clause, wherein a flow of coolant through the first coolant flowpath and the second coolant flowpath are independently adjustable. 
     4. The heat exchange system of any preceding clause, wherein the flow of coolant through the first coolant flowpath and the second coolant flowpath are independently adjustable based on an engine parameter. 
     5. The heat exchange system of any preceding clause, wherein a coolant fluid flowing through the coolant fluid circuit is a fuel. 
     6. The heat exchange system of any preceding clause, further comprising a diverter configured to separate a flow of coolant fluid into the first coolant flowpath and the second coolant flowpath. 
     7. The heat exchange system of any preceding clause, wherein the first heat exchanger, the second heat exchanger, the first coolant flowpath, and the second coolant flowpath form a heat transfer unit that is configured as a heat sink. 
     8. The heat exchange system of any preceding clause, wherein the heat transfer unit is a unitary component. 
     9. The heat exchange system of any preceding clause, wherein the first heat exchanger is coupled to or formed integrally with the second heat exchanger, and wherein the first heat exchanger is in thermal communication with the second heat exchanger. 
     10. The heat exchange system of any preceding clause, wherein the coolant fluid circuit further defines a bypass flowpath that is arranged in the parallel flow configuration with the first and second coolant flowpaths. 
     11. The heat exchange system of any preceding clause, wherein the heat exchange system further comprises a third heat source flowpath extending through a third heat exchanger, and the coolant fluid circuit further defines a third coolant flowpath that extends through the third heat exchanger and is in thermal communication with the third heat source flowpath. 
     12. A gas turbine engine having a compressor section, a combustion section, and a turbine section, the gas turbine engine comprising a first heat generating component and a second heat generating component, and a heat exchange system comprising a first heat exchanger defining a first heat source flowpath, the first heat source flowpath configured to receive a first fluid, the first fluid in thermal communication with the first heat generating component, a second heat exchanger defining a second heat source flowpath, the second heat source flowpath configured to receive a second fluid, the second fluid in thermal communication with the second heat generating component, and a coolant fluid circuit defining a first coolant flowpath extending through the first heat exchanger and in thermal communication with the first heat source flowpath, and a second coolant flowpath extending through the second heat exchanger and in thermal communication with the second heat source flowpath, wherein the first coolant flowpath and the second coolant flowpath are arranged in a parallel flow configuration. 
     13. The gas turbine engine of any preceding clause, wherein the heat source flowpaths are fluidly independent. 
     14. The gas turbine engine of any preceding clause, wherein a flow of coolant through the first coolant flowpath and the second coolant flowpath are independently adjustable. 
     15. The gas turbine engine of any preceding clause, wherein the flow of coolant through the first coolant flowpath and the second coolant flowpath are independently adjustable based on an engine parameter. 
     16. The gas turbine engine of any preceding clause, further comprising a diverter configured to separate a flow of coolant fluid into the first coolant flowpath and the second coolant flowpath. 
     17. The gas turbine engine of any preceding clause, wherein the first heat exchanger, the second heat exchanger, the first coolant flowpath, and the second coolant flowpath form a heat transfer unit that is configured as a heat sink. 
     18. The gas turbine engine of any preceding clause, wherein the first heat exchanger is coupled to or formed integrally with the second heat exchanger, and wherein the first heat exchanger is in thermal communication with the second heat exchanger. 
     19. The gas turbine engine of any preceding clause, wherein the coolant fluid circuit further defines a bypass flowpath that is arranged in the parallel flow configuration with the first and second coolant flowpaths. 
     20. The gas turbine engine of any preceding clause, wherein the heat exchange system further comprises a third heat source flowpath extending through a third heat exchanger, and the coolant fluid circuit further defines a third coolant flowpath that extends through the third heat exchanger and is in thermal communication with the third heat source flowpath.