Patent Description:
During operation, internal combustion engines discharge heat energy into the external environment through exhaust gas, engine cooling systems, charge air cooling systems, etc. The discharged heat energy that is not used to perform useful work may be referred to as "waste heat. " WHR systems capture a portion of the waste heat to perform useful work. Some WHR systems utilize a Rankine cycle. The Rankine cycle is a thermodynamic process in which heat is transferred to a working fluid in a Rankine cycle circuit. The working fluid is pumped to a heat exchanger where it is vaporized. The vapor is passed through an expander and then through a condenser, where the vapor is condensed back to a fluid. The expanding working fluid vapor causes the expander to rotate, thereby converting the waste heat energy to mechanical energy. The mechanical energy may be transmitted to engine system components, such as a pump, a compressor, a generator, etc..

The waste heat can be in the form of hot charge gases exiting a compressor on a turbocharger. To extract heat from the charge gases, a charge air cooler ("CAC") can be used. A charge cooler provides for heat to be exchanged between the charge gases and a working fluid (e.g., a coolant, a refrigerant, etc.) such that heat is transferred from the charge gases to the working fluid. Because the charge gases may be routed back to an intake manifold of the engine, cooling the charge gases to a temperature at which the engine operates efficiently is desirable. However, in some instances a charge cooler with a single core does not provide sufficient cooling to reduce the temperature of the charge gases to a desirable temperature.

D1 (<CIT>) relates to an Organic Rankine Cycle (ORC) Waste Heat Recovery (WHR) System that has an LT working fluid loop and an HT working fluid loop. The working fluid loops may each have a pump, one or more heat exchanger boilers, an expander, and a condenser. A recuperator is arranged within the LT working fluid loop between the pump and the first heat exchanger boiler. D2 (<CIT>) relates to a vehicle with a waste heat recovery (WHR) system and an engine. The WHR system includes a WHR working fluid circuit with a pump, a power turbine, and a condenser. An engine coolant circuit circulates coolant between the engine and an engine coolant heat exchanger/working fluid boiler in the WHR working fluid circuit. At least one exhaust gas heat exchanger/superheater in the WHR working fluid circuit receives waste heat from an exhaust circuit and/or from an exhaust gas recirculation circuit. D3 (<CIT>) relates to a cooling circuit and an independent heat recovery circuit that are associated with an internal combustion engine. A coolant is circulated a pump in a first and a second cooling sub-circuit. An increase in pressure in a work medium is achieved within the heat recovery circuit by a pump. This work medium is changed from liquid aggregate state to vaporous aggregate state and back to the liquid aggregate state in heat exchangers.

An engine system according to the invention is described in claim <NUM>. The engine system comprises a waste heat recovery system. The waste heat recovery system comprises a first charge air cooler in fluid communication with a first working fluid path, a first cooling fluid path, and an air source. The waste heat recovery system further comprises a second charge air cooler is in fluid communication with a second working fluid path, a second cooling fluid path, and the air source. The waste heat recovery system further comprises a first flow control valve selectively directs a portion of a working fluid through the first working fluid path and the remainder of the working fluid through the second working fluid path.

A waste heat recovery system according to the invention is described in claim <NUM> and includes a first charge air cooler in fluid communication with a working fluid path and a source of compressed air. The first charge air cooler is configured to direct the compressed air from a first air inlet to a first air outlet and to direct a working fluid from a first working fluid inlet to a first working fluid outlet. A second charge air cooler is in fluid communication with the working fluid path and the source of compressed air and is configured to direct the compressed air from a second air inlet to a second air outlet and to direct the working fluid from a second working fluid inlet to a second working fluid outlet. The second air inlet is in fluid communication with the first air outlet and the second working fluid inlet is in fluid communication with the first working fluid outlet. A third charge air cooler is in fluid communication with a cooling fluid path and the source of compressed air and is configured to direct the compressed air from a third air inlet to a third air outlet and to direct a cooling fluid from a first cooling fluid inlet to a first cooling fluid outlet. The third air inlet is in fluid communication with the second air outlet, and the third air outlet is in communication with an intake of the engine system.

Other features, aspects, and advantages of the disclosure will become apparent from the description, the drawings, and the claims, in which:.

Following below are more detailed descriptions of various concepts related to, and implementations of, methods, apparatuses, and systems for cooling charge air using a charge air cooler with multiple cores. The various concepts introduced above and discussed in greater detail below may be implemented in any of numerous ways, as the described concepts are not limited to any particular manner of implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes.

A WHR system recovers heat energy that would otherwise be lost from a vehicle component or system, such as from an internal combustion engine of the vehicle. The more waste heat energy that is extracted from the component or system by a WHR system, the greater the potential efficiency of the engine. In other words, rather than the extracted heat being lost, the extracted heat energy may be repurposed to, e.g., supplement the power output from the internal combustion engine, thereby increasing the efficiency of the system.

Implementations herein relate to various WHR systems that incorporate CACs with multiple cores as part of the WHR system. A CAC receives charge air from a compressor of a turbocharger (or other air-handling component, such as a supercharger, e-compressor, etc.), cools the charge air, and provides the charge air to an intake manifold of the engine. The heat that is removed from the charge air is used as part of the WHR system and converted to mechanical energy to provide useful work. A CAC that includes multiple cores is capable of cooling the charge air to a lower temperature than a CAC with a single core. Providing the charge air to the intake manifold at a lower temperature can increase the efficiency of the engine. Additionally, a multi-core CAC may better utilize the available thermal energy of the charge gas to increase the power output or efficiency of the WHR system.

<FIG> are illustrations of a multi-core CAC <NUM> and a WHR system <NUM> incorporating the multi-core CAC <NUM>, respectively. The multi-core CAC <NUM> includes a WHR core <NUM> in fluid communication with a cooling fluid core <NUM>.

The WHR core <NUM> includes a first air inlet <NUM>, a first air outlet <NUM>, a working fluid inlet <NUM>, and a working fluid outlet <NUM>. In some examples, the WHR core <NUM> is structured similarly to a heat exchanger. In such examples, charge air enters the WHR core <NUM> from a compressor of a turbocharger via the first air inlet <NUM> and is directed to the first air outlet <NUM> via a first air conduit (not shown) that couples the first air inlet <NUM> to the first air outlet <NUM>. The charge air enters the first air inlet <NUM> at an elevated temperature (e.g., approximately <NUM>-<NUM> degrees Celsius (<NUM>-<NUM> degrees Fahrenheit)). Working fluid enters the WHR core <NUM> via the working fluid inlet <NUM> and is directed to the working fluid outlet <NUM> via a working fluid conduit (not shown) that couples the working fluid inlet <NUM> to the working fluid outlet <NUM>. The working fluid can be any type of fluid capable of absorbing heat. Examples of the working fluid include, but are not limited to, coolants, refrigerants, high molecular mass fluids, etc. In some arrangements, the first air conduit and the working fluid conduit are adjacent to each other such that at least some heat from the charge air is absorbed by the working fluid, thereby decreasing the temperature of the charge air and increasing the temperature of the working fluid.

The working fluid is directed around a working fluid path <NUM>, which includes the working fluid conduit of the WHR core <NUM>. After exiting the working fluid outlet <NUM>, the working fluid enters a turbine <NUM>, where the heat of working fluid is converted to mechanical energy by the turbine <NUM>. The working fluid continues to a condenser <NUM> that lowers the temperature of the working fluid, and the working fluid is pumped back through the WHR core <NUM> by a pump <NUM>.

In some implementations, the temperature of the charge air exiting the WHR core <NUM> may be above a target intake temperature for the engine. For example, the temperature of the charge air exiting the WHR core <NUM> may be approximately thirty seven degrees Celsius (one hundred degrees Fahrenheit), while the target intake temperature may be between approximately ten degrees and twenty one degrees Celsius (fifty degrees and seventy degrees Fahrenheit). Accordingly, the charge air is directed through the cooling fluid core <NUM> to further reduce the temperature of the charge air.

The cooling fluid core <NUM> includes a second air inlet <NUM>, a second air outlet <NUM>, a cooling fluid inlet <NUM>, and a cooling fluid outlet <NUM>. In some examples, the cooling fluid core <NUM> is structured similarly to a heat exchanger. In such examples, the charge air enters the cooling fluid core <NUM> from the first air outlet <NUM> via the second air inlet <NUM> and is directed to the second air outlet <NUM> via a second air conduit (not shown) that couples the second air inlet <NUM> to the second air outlet <NUM>. Cooling fluid enters the cooling fluid core <NUM> via the cooling fluid inlet <NUM> and is directed to the cooling fluid outlet <NUM> via a cooling fluid conduit (not shown) that couples the cooling fluid inlet <NUM> to the cooling fluid outlet <NUM>. The cooling fluid flowing through the cooling fluid core <NUM> can be any type of cooling fluid including, but not limited to, coolant, refrigerant, water, etc..

In some arrangements where the cooling fluid is water, the temperature of the water at the cooling fluid inlet <NUM> is approximately one to seven degrees Celsius (thirty-five to forty-five degrees Fahrenheit). In some arrangements, the second air conduit and the cooling fluid conduit are adjacent to each other such that at least some heat from the charge air is absorbed by the water, thereby decreasing the temperature of the charge air and increasing the temperature of the water. For example, the temperature of the water at the cooling fluid outlet <NUM> may be approximately ten to fifteen degrees Celsius (fifty to sixty degrees Fahrenheit) and the temperature of the charge air at the second air outlet <NUM> may be approximately twelve to eighteen degrees Celsius (fifty-five to sixty-five degrees Fahrenheit). In some examples, the temperature of the charge air at the second air outlet <NUM> may be approximately equal to the ambient temperature around the vehicle (e.g., the temperature of the charge air may be within plus or minus ten degrees Fahrenheit of the ambient temperature).

Arranged in the manner described, the multi-core CAC <NUM> is configured to reduce the temperature of the charge air exiting the multi-core CAC <NUM> to a target intake temperature (in some examples, the target intake temperature is a temperature approximately equal to the ambient temperature) for the intake of the engine. Providing air to the engine at the target intake temperature reduces the amount of work the engine must do to combat the effects of higher temperatures (e.g., less available oxygen for combustion, engine knocking, etc.), thereby increasing the efficiency or otherwise improving the performance or operation of the engine.

The sizes of the WHR core <NUM> and the cooling fluid core <NUM> can be optimized based on various target characteristics. These characteristics can include power output from the WHR system <NUM>, the target intake temperature, and other characteristics associated with a WHR system. In some embodiments, the WHR core <NUM> may be sized to extract more heat from the charge air than a conventional WHR system such that the temperature of the working fluid entering the turbine is higher than that of a conventional WHR system. This arrangement allows the turbine to convert the higher temperature working fluid to more mechanical work than in a conventional WHR system. In various arrangements, the WHR core <NUM> and/or the cooling fluid core <NUM> may be sized to optimize the temperature of the air at the second air outlet <NUM> such that the air enters the intake manifold at a temperature ideal for engine performance.

In various examples, the charge air entering the WHR core <NUM> may be compressed by a single compressor or by multiple compressors such that the charge air is compressed in stages.

In some arrangements, an intermediate fluid may be used to transfer heat from the air to the working fluid. In such arrangements, additional inputs and/or outputs may be included in the WHR core <NUM> and/or the cooling fluid core <NUM> such that heat is transferred from the air to the intermediate fluid, and from the intermediate fluid to the working fluid.

In some instances, the WHR core <NUM> and the cooling fluid core <NUM> are independently operable such that each core can remain functional in the event that the other core experiences a failure. For example, if the cooling fluid core <NUM> fails (e.g., the cooling fluid stops flowing through the cooling fluid core <NUM> or the cooling fluid flowing through the cooling fluid core <NUM> is not at the appropriate temperature), operation of the WHR core <NUM> can be modified so as to absorb additional heat from the charge air to cool the charge air to an acceptable level and avoid a system failure. In one example, a controller in communication with the WHR system <NUM> may cause the pump <NUM> to increase or decrease the flowrate of working fluid such that the working fluid absorbs additional heat from the charge air. The controller may also cause the condenser <NUM> to lower the temperature of the working fluid entering the pump <NUM> such that the working fluid can absorb additional heat from the charge air.

Conversely, if the WHR core <NUM> fails (e.g., the working fluid stops flowing through the WHR core <NUM> or the working fluid flowing through the WHR core <NUM> is not at the appropriate temperature), operation of the cooling fluid core <NUM> can be modified to absorb additional heat from the charge air to cool the charge air to an acceptable level and avoid a system failure. In such instances, the controller may cause the flow of cooling fluid to increase or decrease such that the cooling fluid absorbs additional heat from the charge air. The controller may also cause the temperature of the cooling fluid entering the cooling fluid core <NUM> to decrease such that the cooling fluid can absorb additional heat from the charge air.

In some examples, the multi-core CAC <NUM> includes various flow control devices (e.g., bypass valves, flow control valves, pumps, etc.) to manage the flow of one or more of the charge air, working fluid, or cooling fluid. For example, a first valve may control the flow of the working fluid such that a flowrate of the working fluid can be set to a desired rate. A second valve may control the flow of the cooling fluid such that a flowrate of the cooling fluid can be set to a desired rate. A third valve may control the flow of charge air such that a flowrate of the charge air can be set to a desired rate. The flowrates of each of the working fluid, cooling fluid, and charge air can be adjusted using the valves to optimize operation of the WHR system <NUM>. Accordingly, using one or more valves, alone or in combination, can isolate one or more cores from other cores.

As shown in <FIG>, the charge air is in counterflow with both the working fluid and the cooling fluid (e.g., the charge air flows in one direction and the working fluid and cooling fluid flow in the opposite direction). However, in various examples any of the fluids described may be in various flow arrangements with the other fluids. Examples of flow arrangements include counterflow, co-flow (e.g., fluids flow in the same direction), cross-flow (e.g., fluids flow in a non-parallel arrangement), or any combination thereof.

<FIG> is an illustration of a two stage dual core CAC system <NUM>, according to a particular example. The two stage dual core CAC system <NUM> includes a low pressure dual core CAC <NUM> in fluid communication with a high pressure dual core CAC <NUM>.

The low pressure dual core CAC <NUM> includes a first WHR core <NUM> and a first cooling fluid core <NUM> and is structured similarly to the multi-core CAC <NUM>. The first WHR core <NUM> includes a first air inlet <NUM> and a first air outlet (not shown) coupled by a first air conduit (not shown). A first working fluid inlet <NUM> and a first working fluid outlet <NUM> are coupled by a first working fluid conduit (not shown). The first cooling fluid core <NUM> includes a second air inlet (not shown) and a second air outlet <NUM> coupled by a second air conduit (not shown), and a first cooling fluid inlet <NUM> coupled to a first cooling fluid outlet <NUM> by a first cooling fluid conduit (not shown). In some examples, air enters the first air inlet <NUM> after being compressed by a low pressure compressor <NUM>. However, the air can enter the first air inlet <NUM> directly (e.g., without first being compressed the by low pressure compressor <NUM>). The low pressure dual core CAC <NUM> is structured similarly to, and operates similarly to, the multi-core CAC <NUM> in that the charge air enters the first air inlet <NUM> at an elevated temperature and is cooled via interactions with both the working fluid of the first WHR core <NUM> and the first cooling fluid core <NUM> such that the temperature of the charge air is lower at the second air outlet <NUM> than at the first air inlet <NUM>.

After exiting the low pressure dual core CAC <NUM> via the second air outlet <NUM>, the charge air is directed to the high pressure dual core CAC <NUM> via the high pressure compressor <NUM>. The high pressure dual core CAC <NUM> includes a second WHR core <NUM> and a second cooling fluid core <NUM>. The second WHR core <NUM> includes a third air inlet <NUM> and a third air outlet (not shown) coupled by a third air conduit (not shown). A second working fluid inlet <NUM> and a second working fluid outlet <NUM> are coupled by a second working fluid conduit (not shown). The second working fluid inlet <NUM> is coupled to the first working fluid outlet <NUM> such that the working fluid exiting the first WHR core <NUM> is directed to the second WHR core <NUM>. The second cooling fluid core <NUM> includes a fourth air inlet (not shown) and a fourth air outlet <NUM> coupled by a fourth air conduit (not shown), and a second cooling fluid inlet <NUM> coupled to a second cooling fluid outlet <NUM> by a second cooling fluid conduit (not shown). The high pressure dual core CAC <NUM> is structured similarly to, and operates similarly to, the multi-core CAC <NUM> in that the charge air enters the third air inlet <NUM> at an elevated temperature and is cooled via interactions with both the working fluid of the second WHR core <NUM> and the second cooling fluid core <NUM> such that the temperature of the charge air is lower at the fourth air outlet <NUM> than at the third air inlet <NUM> and is at the target intake temperature.

In some examples, a cooling fluid supply provides a cooling fluid (e.g., water, coolant, refrigerant, etc.) to the first cooling fluid inlet <NUM> and the second cooling fluid inlet <NUM> such that the temperature of the fluid in the first cooling fluid core <NUM> is substantially the same as the temperature in the second cooling fluid core <NUM>. In various arrangements a first valve may be in fluid communication with the first cooling fluid inlet <NUM>, and a second valve may be in fluid communication with the second cooling fluid inlet <NUM>. The first valve and the second valve may be operated independently of each other such that the flow of cooling fluid from the cooling fluid supply can be directed to both of the first cooling fluid core <NUM> and the second cooling fluid core <NUM>, only one of the first cooling fluid core <NUM> and the second cooling fluid core <NUM>, or neither of the first cooling fluid core <NUM> and the second cooling fluid core <NUM>, as desired. Operation of the first valve and the second valve may be based on the temperature of the charge air at the fourth air outlet <NUM>. For example, if the temperature of the charge air at the fourth air outlet <NUM> is lower than the target intake temperature, one or both of the first valve and the second valve may be used to stop the flow of cooling fluid to increase the temperature of the charge air to the target intake temperature.

The second air outlet <NUM> is fluidly coupled to a third air inlet <NUM> such that the charge air is directed from the second air outlet <NUM> to the third air inlet <NUM>. In some examples, the charge air is directed through a high pressure compressor <NUM> to compress the charge air, thereby increasing the temperature of the charge air. In some arrangements, the charge air is directed to the third air inlet <NUM> without being compressed by the high pressure compressor <NUM>.

<FIG> is an illustration of a WHR system <NUM> that incorporates the two stage dual core CAC system <NUM> in series, according to a particular example. As shown, the WHR system <NUM> includes a low pressure working fluid path <NUM> and a high pressure working fluid path <NUM>. The low pressure working fluid path <NUM> is configured to receive heat from sources that are typically at a relatively low temperature (e.g., fifty to one hundred fifty degrees Celsius) compared to the sources used on the high pressure working fluid path <NUM>, and is in fluid communication with the two stage dual core CAC system <NUM>, which is arranged in series. A series arrangement refers to the flow of the working fluid in the low pressure working fluid path <NUM>, in that the working fluid passes through the first WHR core <NUM> and then the second WHR core <NUM> before being directed to a dual inlet turbine <NUM>.

The high pressure working fluid path <NUM> is configured to receive heat from exhaust gas or other type of fluid or gas at a pressure that is higher than that of the heat sources used in the low pressure working fluid path <NUM>.

The working fluid from the low pressure working fluid path <NUM> and the working fluid from the high pressure working fluid path <NUM> are both directed to the dual inlet turbine <NUM>, which includes a first inlet in fluid communication with the low pressure working fluid path <NUM> and a second inlet in fluid communication with the high pressure working fluid path <NUM>. The dual inlet turbine <NUM> is configured to receive both low pressure working fluid and high pressure working fluid and covert the thermal energy of those working fluids to mechanical work.

<FIG> is an illustration of a WHR system <NUM> that incorporates the two stage dual core CAC system <NUM> in parallel, according to a particular embodiment. As shown, the WHR system <NUM> includes a low pressure working fluid path <NUM> and a high pressure working fluid path <NUM>. The low pressure working fluid path <NUM> is configured to receive heat from sources that are typically at a relatively lower temperature (e.g., fifty to one hundred fifty degrees Celsius) compared to the sources used on the high pressure working fluid path <NUM>, and is in fluid communication with the two stage dual core CAC system <NUM>, which is arranged in parallel. A parallel arrangement refers to the way in which the working fluid can be directed through the two stage dual core CAC system <NUM> (e.g., the working fluid can be directed independently through either or both of the low pressure dual core CAC <NUM> and the high pressure dual core CAC <NUM>).

The low pressure dual core CAC <NUM> is in fluid communication with the low pressure working fluid path <NUM>, and the high pressure dual core CAC <NUM> is in fluid communication with the high pressure working fluid path <NUM>. A first valve <NUM> is in fluid communication with the low pressure working fluid path <NUM> and is operable to direct the working fluid through the low pressure working fluid path <NUM> or prevent the working fluid from flowing through the low pressure working fluid path <NUM>. A second valve (not shown) may be positioned in or on the high pressure working fluid path <NUM> and is operable to direct the working fluid through the high pressure working fluid path <NUM> or prevent the working fluid from flowing through the high pressure working fluid path <NUM>. Accordingly, based on the arrangement of the first valve <NUM> and the second valve, the working fluid can be directed through one or both of the first WHR core <NUM> and the second WHR core <NUM>, or the working fluid can be prevented from flowing through both of the first WHR core <NUM> and the second WHR core <NUM>.

The decision as to how much working fluid is allowed through either, neither, or both of the first WHR core <NUM> and the second WHR core <NUM> may be based on the temperature of the charge air as it exits the high pressure dual core CAC <NUM>. For example, in some embodiments the working fluid may be flowing through both the first WHR core <NUM> and the second WHR core <NUM>. The temperature of the charge air as it exits the high pressure dual core CAC <NUM> may be lower than the target intake temperature. In such instances, one or both of the first valve <NUM> and the second valve may be operated to prevent the working fluid from flowing through one or both of the first WHR core <NUM> and the second WHR core <NUM> to increase the temperature of the charge air as it exits the high pressure dual core CAC <NUM>. As another example, in some embodiments the working fluid may be flowing through only the second WHR core <NUM> (e.g., the first valve <NUM> is closed to prevent the working fluid from flowing through the first WHR core <NUM>). The temperature of the charge air as it exits the high pressure dual core CAC <NUM> may be higher than the target intake temperature. In this example embodiment, the first valve <NUM> may be opened to allow the working fluid to flow through the first WHR core <NUM> to decrease the temperature of the charge air exiting the high pressure dual core CAC <NUM> to the target intake temperature.

The working fluid from the low pressure working fluid path <NUM> and the working fluid from the high pressure working fluid path <NUM> are both directed to a dual inlet turbine <NUM>. The dual inlet turbine includes a first inlet in fluid communication with the low pressure working fluid path <NUM> and a second inlet in fluid communication with the high pressure working fluid path <NUM>. The dual inlet turbine <NUM> is configured to receive both low pressure working fluid and high pressure working fluid and covert the thermal energy of those working fluids to mechanical work.

<FIG> are illustrations of a triple core CAC system <NUM> and a WHR system <NUM> incorporating the triple core CAC system <NUM>, respectively, according to a particular embodiment. As shown, the triple core CAC system <NUM> includes a cooling fluid core <NUM>, a preheater core <NUM>, a superheater core <NUM>, and a WHR boiler <NUM>.

The cooling fluid core <NUM> includes a cooling fluid inlet <NUM> coupled to a cooling fluid outlet <NUM> via a cooling fluid conduit (not shown). The cooling fluid inlet <NUM> is in fluid communication with a cooling fluid source that provides cooling fluid (e.g., water, coolant, refrigerant, etc.) to the cooling fluid inlet <NUM>. The cooling fluid core <NUM> also includes a third air inlet (not shown) coupled to a third air outlet <NUM> by a third air conduit, where the third air outlet <NUM> is in fluid communication with an intake of the engine (or, in some embodiments, to the intake via further compression stages). In some embodiments, the cooling fluid conduit and the third air conduit are adjacent to each other such that at least some heat from the charge air is absorbed by the cooling fluid, thereby decreasing the temperature of the charge air and increasing the temperature of the cooling fluid.

The preheater core <NUM> includes a first working fluid inlet <NUM> coupled to a first working fluid outlet <NUM> via a first working fluid conduit (not shown). The first working fluid inlet <NUM> is in fluid communication with a low pressure working fluid path <NUM> such that the working fluid in the low pressure working fluid path <NUM> is directed to the first working fluid inlet <NUM>. The preheater core <NUM> also includes a second air inlet (not shown) coupled to a second air outlet (not shown) by a second air conduit, where the second air outlet is in fluid communication with the third air inlet. In some embodiments, the first working fluid conduit and the second air conduit are adjacent to each other such that at least some heat from the charge air is absorbed by the working fluid, thereby decreasing the temperature of the charge air and increasing the temperature of the working fluid.

The superheater core <NUM> includes a second working fluid inlet <NUM> coupled to a second working fluid outlet <NUM> via a second working fluid conduit (not shown), where the second working fluid inlet <NUM> is in fluid communication with the first working fluid outlet <NUM>. The superheater core <NUM> also includes a first air inlet <NUM> and a first air outlet (not shown) coupled to the first air inlet <NUM> via a first air conduit, where the first air outlet is in fluid communication with the second air inlet. The first air inlet <NUM> is configured to receive charge air from a compressor of a turbocharger. In some arrangements, the second working fluid conduit and the first air conduit are adjacent to each other such that at least some heat from the charge air is absorbed by the working fluid, thereby decreasing the temperature of the charge air and increasing the temperature of the working fluid.

The WHR boiler <NUM> is positioned between the first working fluid outlet <NUM> and the second working fluid inlet <NUM> and is configured to heat the working fluid, partially or completely boiling the working fluid.

In operation, the triple core CAC system <NUM> is configured to receive charge air from a turbocharger at the first air inlet <NUM>, where the charge air is at an elevated temperature (e.g., approximately <NUM>-<NUM> degrees Celsius (<NUM>-<NUM> degrees Fahrenheit)). The triple core CAC system <NUM> is also configured to receive a working fluid from the low pressure working fluid path <NUM> at a low temperature (e.g., approximately <NUM>-<NUM> degrees Celsius (<NUM>-<NUM> degrees Fahrenheit) at the first working fluid inlet <NUM> and cooling fluid at a low temperature (e.g., approximately <NUM>-<NUM> degrees Celsius (<NUM>-<NUM> degrees Fahrenheit)) at the cooling fluid inlet <NUM>.

As the charge air flows through the first air conduit, the second air conduit, and the third air conduit, the temperature of the charge air decreases as the temperature of the cooling fluid in the cooling fluid conduit and the working fluid in the first working fluid conduit and the second working fluid conduit increases. At the third air outlet <NUM>, the temperature of the air reaches approximately the target intake temperature and is provided to the intake manifold (or, in some embodiments, to the intake manifold via further compression stages, or a compressor inlet).

In this example embodiment, the WHR boiler <NUM> is used to heat the working fluid before the working fluid enters the superheater core <NUM>. Heating the working fluid as described allows the charge air to cool as it flows through the superheater core <NUM>, and increases the thermal energy of the working fluid as heat from the charge air is transferred from the working fluid. Increasing the thermal energy of the working fluid as described provides for efficient waste heat recovery and provides for more mechanical power from the WHR system <NUM> than if the WHR boiler <NUM> was not used.

The WHR system <NUM> includes the low pressure working fluid path <NUM> and a high pressure working fluid path <NUM>, where the triple core CAC system <NUM> is positioned along the low pressure working fluid path <NUM>. The working fluid from the low pressure working fluid path <NUM> is directed from the triple core CAC system <NUM> to a dual inlet turbine <NUM>. The dual inlet turbine <NUM> is configured to receive both low pressure working fluid and high pressure working fluid and convert the thermal energy of those working fluids to mechanical work.

As utilized herein, the term "substantially," "approximately," and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described are considered to be within the scope of the invention as recited in the appended claims.

The terms "coupled" and the like, as used herein, mean the joining of two components directly or indirectly to one another. Such joining may be stationary (e.g., permanent) or moveable (e.g., removable or releasable). Such joining may be achieved with the two components or the two components and any additional intermediate components being integrally formed as a single unitary body with one another, with the two components, or with the two components and any additional intermediate components being attached to one another.

It is important to note that the construction and arrangement of the system shown in the various example implementations is illustrative only and not restrictive in character. It should be understood that some features may not be necessary, and implementations lacking the various features may be contemplated as within the scope of the application, the scope being defined by the claims that follow. When the language a "portion" is used, the item can include a portion and/or the entire item unless specifically stated to the contrary.

Claim 1:
An engine system, comprising:
a waste heat recovery system (<NUM>), comprising:
a first charge air cooler (<NUM>) in fluid communication with a first working fluid path (<NUM>), a first cooling fluid path, and an air source; a second charge air cooler (<NUM>) in fluid communication with a second working fluid path (<NUM>) a second cooling fluid path, and the air source; and
a first flow control valve (<NUM>) selectively directing a portion of a working fluid through the first working fluid path (<NUM>) and a remainder of the working fluid through the second working fluid path (<NUM>).