Multi-core heat recovery charge air cooler

Abstract

A waste heat recovery system for an engine system includes a first charge air cooler in communication with a working fluid path of the waste heat recovery system. The first charge air cooler includes a first waste heat recovery core and a first cooling fluid core. The first waste heat recovery core includes a first working fluid inlet configured to receive working fluid from the working fluid path. A first working fluid conduit is coupled to the first working fluid inlet and the first working fluid outlet. The first cooling fluid core includes a first cooling fluid inlet in fluid communication with a cooling fluid source and a first cooling fluid conduit fluidly coupled to the first cooling fluid inlet and the first cooling fluid outlet. The first cooling fluid conduit is configured to direct cooling fluid from the first cooling fluid inlet to the first cooling fluid outlet.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 62 / 993,253, filed on March 23, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure generally relates to the field of waste heat recovery ("WHR") systems for engine systems.

[0004] background

[0005] During operation, an internal combustion engine discharges heat energy to the external environment through exhaust gases, engine cooling systems, charge air cooling systems, etc. This discharged heat energy that is not used to do useful work can be called "waste heat". The WHR system captures some of the waste heat to do useful work. Some WHR systems utilize the Rankine cycle. The Rankine cycle is a thermodynamic process that transfers heat to a working fluid in a Rankine cycle loop. The working fluid is pumped to a heat exchanger where it is vaporized. The vapor passes through an expander and then through a condenser where it is condensed back into a fluid. The expanded working fluid vapor causes the expander to rotate, thereby converting the waste heat energy into mechanical energy. The mechanical energy can be transferred to engine system components such as pumps, compressors, generators, etc.

[0006] Waste heat can be exhausted from the compressor on a turbocharger in the form of hot charge gases. To extract heat from the charge gases, a charge air cooler ("CAC") can be used. The charge cooler provides heat exchange between the charge gases and a working fluid (e.g., coolant, refrigerant, etc.), transferring heat from the charge gases to the working fluid. Because the charge gases may be returned to the intake manifold of the engine, it is desirable to cool the charge gases to a temperature at which the engine operates efficiently. However, in some cases, a charge cooler with a single core may not provide sufficient cooling to reduce the temperature of the charge gases to the desired level.

[0007] Overview

[0008] In one set of embodiments, a waste heat recovery system for an engine system includes a first charge air cooler in fluid communication with a working fluid path of the waste heat recovery system. The first charge air cooler includes a first waste heat recovery core and a first cooling fluid core. The first waste heat recovery core includes a first working fluid inlet configured to receive working fluid from the working fluid path. A first working fluid conduit is fluidly coupled to the first working fluid inlet and a first working fluid outlet, and the first working fluid conduit is configured to direct working fluid from the first working fluid inlet to the first working fluid outlet. A first air conduit is adjacent to the first working fluid conduit and in fluid communication with a first air inlet and a first air outlet. The first air conduit is configured to direct air from the first air inlet to the first air outlet, and the first air inlet is in fluid communication with an air source. The first cooling fluid core includes a first cooling fluid inlet in fluid communication with a cooling fluid source and a first cooling fluid conduit fluidly coupled to the first cooling fluid inlet and a first cooling fluid outlet. The first cooling fluid conduit is configured to direct cooling fluid from the first cooling fluid inlet to the first cooling fluid outlet. A second air conduit is adjacent to the first cooling fluid conduit and in fluid communication with a second air inlet and a second air outlet. The second air conduit is configured to direct air from the second air inlet to the second air outlet. The second air inlet is in fluid communication with the first air outlet, and the second air outlet is in fluid communication with an intake of the engine or a compressor inlet of the engine.

[0009] In some embodiments, the first air conduit is configured to transfer heat from the air to the first working fluid conduit, thereby reducing a temperature of the air from a first temperature to a second temperature.

[0010] In some embodiments, the second air conduit is configured to transfer heat from the air to the first cooling fluid conduit, thereby reducing a temperature of the air from the second temperature to a third temperature.

[0011] In some embodiments, the waste heat recovery system further includes:

[0012] a second charge air cooler in fluid communication with the working fluid path, the second charge air cooler including:

[0013] a second waste heat recovery core, the second waste heat recovery core including:

[0014] a second working fluid inlet configured to receive working fluid from the first working fluid outlet;

[0015] a second working fluid conduit fluidly coupled to the second working fluid inlet and a second working fluid outlet, the second working fluid conduit configured to direct working fluid from the second working fluid inlet to the second working fluid outlet; and

[0016] a third air conduit adjacent to the second working fluid conduit, the third air conduit in fluid communication with a third air inlet and a third air outlet, and the third air conduit configured to direct air from the third air inlet to the third air outlet, the third air inlet in fluid communication with the second air outlet; and

[0017] a second cooling fluid core, the second cooling fluid core comprising:

[0018] a second cooling fluid inlet in fluid communication with the first cooling fluid outlet; and

[0019] a second cooling fluid conduit fluidly coupled to the second cooling fluid inlet and a second cooling fluid outlet, the second cooling fluid conduit configured to direct the cooling fluid from the second cooling fluid inlet to the second cooling fluid outlet; and

[0020] a fourth air conduit adjacent to the second cooling fluid conduit, the fourth air conduit in fluid communication with a fourth air inlet and a fourth air outlet, and the fourth air conduit configured to direct air from the fourth air inlet to the fourth air outlet, the fourth air inlet in fluid communication with the third air outlet, the fourth air outlet in fluid communication with the intake of the engine.

[0021] In some embodiments, the waste heat recovery system further comprises:

[0022] a low pressure working fluid path, the second charge air cooler located within the low pressure working fluid path;

[0023] a high pressure working fluid path; and

[0024] a dual input turbine configured to receive working fluid from the low pressure working fluid path and the high pressure working fluid path.

[0025] In some embodiments, the first charge air cooler is in fluid communication with a low pressure working fluid path, the waste heat recovery system further comprising:

[0026] a second charge air cooler in fluid communication with a high pressure working fluid path, the second charge air cooler comprising:

[0027] a second waste heat recovery core, the second waste heat recovery core comprising:

[0028] a second working fluid inlet configured to receive working fluid from the high pressure working fluid path;

[0029] a second working fluid conduit fluidly coupled to the second working fluid inlet and a second working fluid outlet, the second working fluid conduit configured to direct working fluid from the second working fluid inlet to the second working fluid outlet; and

[0030] a third air conduit adjacent to the second working fluid conduit, the third air conduit in fluid communication with a third air inlet and a third air outlet, and the third air conduit configured to direct air from the third air inlet to the third air outlet, the third air inlet in fluid communication with the second air outlet; and

[0031] a second cooling fluid core, the second cooling fluid core comprising:

[0032] a second cooling fluid inlet in fluid communication with the cooling fluid source; and

[0033] a second cooling fluid conduit fluidly coupled to the second cooling fluid inlet and a second cooling fluid outlet, the second cooling fluid conduit configured to direct the cooling fluid from the second cooling fluid inlet to the second cooling fluid outlet; and

[0034] a fourth air conduit adjacent to the second cooling fluid conduit, the fourth air conduit in fluid communication with a fourth air inlet and a fourth air outlet, and the fourth air conduit configured to direct air from the fourth air inlet to the fourth air outlet, the fourth air inlet in fluid communication with the third air outlet, the fourth air outlet in fluid communication with the intake of the engine.

[0035] In some embodiments, the waste heat recovery system further comprises a dual input turbine configured to receive working fluid from the low pressure working fluid path and the high pressure working fluid path.

[0036] In another set of embodiments, an engine system is provided. The engine system includes a waste heat recovery system. The waste heat recovery system includes 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 includes a second charge air cooler in fluid communication with a second working fluid path, a second cooling fluid path, and the air source. The waste heat recovery system further includes a first flow control valve that selectively directs a portion of working fluid through the first working fluid path and directs a remaining portion of working fluid through the second working fluid path.

[0037] In some embodiments, the engine system further comprises a second flow control valve that selectively directs cooling fluid through the first cooling fluid path.

[0038] In some embodiments, the engine system further comprises a third flow control valve that selectively directs the cooling fluid through the second cooling fluid path.

[0039] In some embodiments, the engine system further comprises:

[0040] a first air conduit extending from a first air inlet of the first charge air cooler to a first air outlet of the first charge air cooler; and

[0041] a low pressure compressor in fluid communication with the air source and the first air conduit.

[0042] In some embodiments, the engine system further comprises:

[0043] a second air conduit extending from a second air inlet of the second charge air cooler to a second air outlet of the second charge air cooler; and

[0044] a high pressure compressor in fluid communication with the first air outlet and the second air inlet.

[0045] In some embodiments, the first working fluid path comprises a low pressure working fluid and the second working fluid path comprises a high pressure working fluid.

[0046] In some embodiments, the engine system further comprises a dual inlet turbine in fluid communication with the first working fluid path and the second working fluid path, the dual inlet turbine configured to receive the low pressure working fluid and the high pressure working fluid.

[0047] In some embodiments, the engine system further comprises an additional valve in fluid communication with the second working fluid path, the additional valve configured to selectively direct a portion of working fluid through the second working fluid path.

[0048] In yet another set of embodiments, a waste heat recovery system for an engine system includes a first charge air cooler in fluid communication with a working fluid path and a compressed air source. The first charge air cooler is configured to direct compressed air from a first air inlet to a first air outlet and to direct 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 compressed air source and is configured to direct compressed air from a second air inlet to a second air outlet and to direct 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 compressed air source and the third charge air cooler is configured to direct compressed air from a third air inlet to a third air outlet and to direct 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 air intake of the engine system.

[0049] In some embodiments, the waste heat recovery system further includes a boiler in fluid communication with the first charge air cooler and the second charge air cooler, the boiler configured to receive working fluid from the second working fluid outlet and direct working fluid to the first working fluid inlet.

[0050] In some embodiments, the boiler partially or completely boils the working fluid prior to directing the working fluid to the first working fluid inlet.

[0051] In some embodiments, the working fluid is a low pressure working fluid.

[0052] In some embodiments, the waste heat recovery system further includes a turbine configured to receive the low pressure working fluid and a high pressure working fluid and convert a first thermal energy of the low pressure working fluid and a second thermal energy of the high pressure working fluid to mechanical work. BRIEF DESCRIPTION OF DRAWINGS

[0054] The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the disclosure will become apparent from the description, the drawings, and the claims.

[0055] Figures 1-2 is an illustration of a dual core CAC and a WHR system containing the dual core CAC according to particular embodiments.

[0056] Figure 3 is an illustration of a two stage dual core CAC system according to particular embodiments.

[0057] Figure 4 is an illustration of a WHR system 400 including a two-stage dual-core CAC system 300 in series, according to certain embodiments.

[0058] Figure 5 is an illustration of a WHR system 500 including a two-stage dual-core CAC system 300 in parallel, according to certain embodiments.

[0059] Figures 6-7 is an illustration of a three-core CAC and a WHR system including the three-core CAC, according to certain embodiments.

[0060] DETAILED DESCRIPTION

[0061] The following is a more detailed description of various concepts and embodiments related to methods, apparatus, and systems for cooling charge air using a charge air cooler having multiple cores. The various concepts introduced above and discussed in greater detail below can be implemented in any of a variety of ways, because the described concepts are not limited to any particular manner of implementation. The specific embodiments and examples provided are intended to illustrate, but not limit, the concepts.

[0062] I. OVERVIEW

[0063] 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 a vehicle. The more waste heat energy that a WHR system extracts from a component or system, the higher the potential efficiency of the engine. In other words, rather than being lost, the extracted heat energy can be reused to, for example, supplement the power output from the internal combustion engine, thereby increasing the efficiency of the system.

[0064] Embodiments herein relate to various WHR systems that include a CAC having multiple cores as part of the WHR system. The CAC receives charge air from a compressor of a turbocharger (or other air handling component, such as a supercharger, an e-compressor, etc.), cools the charge air, and provides the charge air to an intake manifold of an engine. The heat extracted from the charge air is used as part of the WHR system and converted to mechanical energy to provide useful work. A CAC including multiple cores is able to cool charge air to a lower temperature than a CAC having a single core. Providing charge air to the intake manifold at a lower temperature can increase the efficiency of the engine. Moreover, a multi-core CAC can better utilize the available heat energy of the charge air to increase the power output or efficiency of the WHR system.

[0065] II. DUAL-CORE CAC SYSTEM

[0066] Figures 1-2are illustrations of a multi-core CAC 100 and a WHR system 200 including the multi-core CAC 100, respectively. The multi-core CAC 100 includes a WHR core 110 in fluid communication with a cooling fluid core 120.

[0067] The WHR core 110 includes a first air inlet 112, a first air outlet 114, a working fluid inlet 116, and a working fluid outlet 118. In some embodiments, the structure of the WHR core 110 is similar to a heat exchanger. In such embodiments, the charge air enters the WHR core 110 from the compressor of the turbocharger via the first air inlet 112 and is directed to the first air outlet 114 via a first air conduit (not shown) that couples the first air inlet 112 to the first air outlet 114. The charge air enters the first air inlet 112 at an elevated temperature (e.g., approximately 150-200 degrees Fahrenheit). The working fluid enters the WHR core 110 via the working fluid inlet 116 and is directed to the working fluid outlet 118 via a working fluid conduit (not shown) that couples the working fluid inlet 116 to the working fluid outlet 118. The working fluid can be any type of fluid capable of absorbing heat. Examples of working fluids include, but are not limited to, coolant, refrigerant, high molecular mass fluid, 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 reducing the temperature of the charge air and increasing the temperature of the working fluid.

[0068] The working fluid is directed around a working fluid path 202 that includes the working fluid conduit of the WHR core 110. After exiting the working fluid outlet 118, the working fluid enters a turbine 208 at which heat of the working fluid is converted to mechanical energy by the turbine 208. The working fluid continues to enter a condenser 206 that reduces the temperature of the working fluid, and the working fluid is pumped back through the WHR core 110 by a pump 204.

[0069] In some implementations, the temperature of the charge air exiting the WHR core 110 can be higher than a target intake air temperature of the engine. For example, the temperature of the charge air exiting the WHR core 110 can be approximately 100 degrees Fahrenheit, while the target intake air temperature can be between approximately 50 and 70 degrees Fahrenheit. Accordingly, the charge air is directed through the cooling fluid core 120 to further reduce the temperature of the charge air.

[0070] The cooling fluid core 120 includes a second air inlet 122, a second air outlet 124, a cooling fluid inlet 126, and a cooling fluid outlet 128. In some embodiments, the cooling fluid core 120 is structured similarly to a heat exchanger. In such embodiments, the charge air enters the cooling fluid core 120 from the first air outlet 114 via the second air inlet 122 and is directed to the second air outlet 124 via a second air conduit (not shown) that couples the second air inlet 122 to the second air outlet 124. The cooling fluid enters the cooling fluid core 120 via the cooling fluid inlet 126 and is directed to the cooling fluid outlet 128 via a cooling fluid conduit (not shown) that couples the cooling fluid inlet 126 to the cooling fluid outlet 128. The cooling fluid that flows through the cooling fluid core 120 can be any type of cooling fluid, including but not limited to coolant, refrigerant, water, etc.

[0071] In some arrangements in which the cooling fluid is water, the temperature of the water at the cooling fluid inlet 126 is approximately 35 to 45 degrees Fahrenheit. In some arrangements, the second air conduit and the cooling fluid conduit are adjacent to one another such that at least some heat from the charge air is absorbed by the water, thereby reducing 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 128 can be approximately 50 to 60 degrees Fahrenheit, and the temperature of the charge air at the second air outlet 124 can be approximately 55 to 65 degrees Fahrenheit. In some embodiments, the temperature of the charge air at the second air outlet 124 can be approximately equal to the ambient temperature around the vehicle (e.g., the temperature of the charge air can be within plus or minus 10 degrees Fahrenheit of the ambient temperature).

[0072] Arranged in this manner, the multi-core CAC 100 is configured to reduce the temperature of the charge air that exits the multi-core CAC 100 to a target intake temperature for engine intake air (in some embodiments, the target intake temperature is a temperature that is approximately equal to the ambient temperature). Providing air to the engine at the target intake temperature reduces the amount of work that the engine must do to counteract the effects of higher temperatures (e.g., less available oxygen for combustion, engine knock, etc.), thereby increasing the efficiency of the engine or otherwise improving the performance or operation of the engine.

[0073] The dimensions of the WHR core 110 and the cooling fluid core 120 can be optimized based on various target characteristics. These characteristics can include power output from the WHR system 200, target intake air temperature, and other characteristics associated with the WHR system. In some embodiments, the WHR core 110 can 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 the temperature of a conventional WHR system. This arrangement allows the turbine to convert the higher temperature working fluid into more mechanical work than in a conventional WHR system. In various arrangements, the WHR core 110 and / or the cooling fluid core 120 can be sized to optimize the temperature of the air at the second air outlet 124, such that the air enters the intake manifold at a temperature that is ideal for engine performance.

[0074] In various embodiments, the charge air entering the WHR core 110 can be compressed by a single compressor or by multiple compressors, such that the charge air is compressed in stages.

[0075] In some arrangements, an intermediate fluid can be used to transfer heat from the air to the working fluid. In such arrangements, additional input ports and / or output ports can be included in the WHR core 110 and / or the cooling fluid core 120, such that heat is transferred from the air to the intermediate fluid, and from the intermediate fluid to the working fluid.

[0076] In some cases, the WHR core 110 and the cooling fluid core 120 are independently operable, such that in the event of a failure of one core, the individual cores can remain operational. For example, if the cooling fluid core 120 fails (e.g., the cooling fluid stops flowing through the cooling fluid core 120 or the cooling fluid flowing through the cooling fluid core 120 is not at an appropriate temperature), the operation of the WHR core 110 can be modified in order to absorb additional heat from the charge air, to cool the charge air to an acceptable level and to avoid system failure. In one embodiment, a controller in communication with the WHR system 200 can cause the pump 204 to increase or decrease the flow rate of the working fluid, such that the working fluid absorbs additional heat from the charge air. The controller can also cause the condenser 206 to lower the temperature of the working fluid entering the pump 204, such that the working fluid can absorb additional heat from the charge air.

[0077] Conversely, if the WHR core 110 fails (e.g., the working fluid stops flowing through the WHR core 110, or the working fluid flowing through the WHR core 110 is not at an appropriate temperature), the operation of the cooling fluid core 120 can be modified to absorb additional heat from the charge air, thereby cooling the charge air to an acceptable level and avoiding system failure. In this case, the controller can increase or decrease the flow rate of the cooling fluid so that the cooling fluid absorbs additional heat from the charge air. The controller can also reduce the temperature of the cooling fluid entering the cooling fluid core 120 so that the cooling fluid can absorb additional heat from the charge air.

[0078] In some embodiments, the multi-core CAC 100 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 can control the flow of the working fluid so that the flow rate of the working fluid can be set to a desired rate. A second valve can control the flow of the cooling fluid so that the flow rate of the cooling fluid can be set to a desired rate. A third valve can control the flow of the charge air so that the flow rate of the charge air can be set to a desired rate. Valves can be used to adjust the flow rate of each of the working fluid, cooling fluid, and charge air to optimize the operation of the WHR system 200. Thus, one or more valves, used individually or in combination, can be used to isolate one or more cores from the other cores.

[0079] like Figure 2 As shown, the charge air is counter-flow relative to both the working fluid and the cooling fluid (e.g., the charge air flows in one direction, while the working fluid and the cooling fluid flow in opposite directions). However, in various embodiments, any of the fluids described can be in various flow arrangements with other fluids. Examples of flow arrangements include counter-flow, co-flow (e.g., the fluids flow in the same direction), cross-flow (e.g., the fluids flow in a non-parallel arrangement), or any combination thereof.

[0080] The various embodiments described above of the present disclosure should not be interpreted as being limited to a specific arrangement. For example, the various embodiments and alternatives described above can be applied to any of the embodiments described subsequently below.

[0081] III. Two-stage dual-core CAC system

[0082] Figure 3 is a diagram of a two-stage, dual-core CAC system 300 , according to certain embodiments. The two-stage, dual-core CAC system 300 includes a low-pressure, dual-core CAC 310 in fluid communication with a high-pressure, dual-core CAC 330 .

[0083] The low-pressure dual-core CAC 310 includes a first WHR core 350 and a first cooling fluid core 360, and its structure is similar to the multi-core CAC 100. The first WHR core 350 includes a first air inlet 312 and a first air outlet (not shown) coupled by a first air duct (not shown). A first working fluid inlet 316 and a first working fluid outlet 318 are coupled by a first working fluid duct (not shown). The first cooling fluid core 360 includes a second air inlet (not shown) and a second air outlet 314 coupled by a second air duct (not shown), and a first cooling fluid inlet 320 coupled to a first cooling fluid outlet 322 by a first cooling fluid duct (not shown). In some embodiments, air enters the first air inlet 312 after being compressed by the low-pressure compressor 302. However, air can enter the first air inlet 312 directly (e.g., without first being compressed by the low-pressure compressor 302). The structure and operation of the low-pressure dual-core CAC 310 is similar to the multi-core CAC 100, i.e., the charge air enters the first air inlet 312 at an elevated temperature and is cooled by interacting with both the working fluid of the first WHR core 350 and the first cooling fluid core 360, such that the temperature of the charge air at the second air outlet 314 is lower than at the first air inlet 312.

[0084] After exiting the low-pressure dual-core CAC 310 via the second air outlet 314, the charge air is directed to the high-pressure dual-core CAC 330 via the high-pressure compressor 324. The high-pressure dual-core CAC 330 includes a second WHR core 370 and a second cooling fluid core 380. The second WHR core 370 includes a third air inlet 332 and a third air outlet (not shown) coupled by a third air duct (not shown). A second working fluid inlet 336 and a second working fluid outlet 338 are coupled by a second working fluid duct (not shown). The second working fluid inlet 336 is coupled to the first working fluid outlet 318, such that the working fluid exiting the first WHR core 350 is directed to the second WHR core 370. The second cooling fluid core 380 includes a fourth air inlet (not shown) and a fourth air outlet 334 coupled by a fourth air duct (not shown), and a second cooling fluid inlet 340 coupled to a second cooling fluid outlet 342 by a second cooling fluid duct (not shown). The structure and operation of the high-pressure dual-core CAC 330 is similar to the multi-core CAC 100, i.e., the charge air enters the third air inlet 332 at an elevated temperature and is cooled by interacting with both the working fluid of the second WHR core 370 and the second cooling fluid core 380, such that the temperature of the charge air at the fourth air outlet 334 is lower than at the third air inlet 332 and at the target intake air temperature.

[0085] In some embodiments, a cooling fluid supply provides cooling fluid (e.g., water, coolant, refrigerant, etc.) to the first cooling fluid inlet 320 and the second cooling fluid inlet 340 such that the temperature of the fluid in the first cooling fluid core 360 is substantially the same as the temperature in the second cooling fluid core 380. In various arrangements, a first valve can be in fluid communication with the first cooling fluid inlet 320 and a second valve can be in fluid communication with the second cooling fluid inlet 340. The first valve and the second valve can operate independently of one another such that the flow of cooling fluid from the cooling fluid supply can be directed to both the first cooling fluid core 360 and the second cooling fluid core 380, to only one of the first cooling fluid core 360 and the second cooling fluid core 380, or to neither of the first cooling fluid core 360 and the second cooling fluid core 380 as desired. The operation of the first valve and the second valve can be based on the temperature of the charge air at the fourth air outlet 334. For example, if the temperature of the charge air at the fourth air outlet 334 is below the target intake air temperature, one or both of the first valve and the second valve can be used to stop the flow of cooling fluid to increase the temperature of the charge air to the target intake air temperature.

[0086] The second air outlet 314 is fluidly coupled to the third air inlet 332 such that charge air is directed from the second air outlet 314 to the third air inlet 332. In some embodiments, the charge air is directed through the high pressure compressor 324 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 332 without being compressed by the high pressure compressor 324.

[0087] Figure 4 is an illustration of a WHR system 400 including a two-stage, dual-core CAC system 300 in series according to particular embodiments. As shown, the WHR system 400 includes a low pressure working fluid path 402 and a high pressure working fluid path 404. The low pressure working fluid path 402 is configured to receive heat from a source that is typically at a relatively lower temperature (e.g., 50 to 150 degrees Celsius) compared to the source used on the high pressure working fluid path 404 and is in fluid communication with the two-stage, dual-core CAC system 300 in series. The series arrangement refers to the flow of working fluid in the low pressure working fluid path 402, i.e., the working fluid passes through the first WHR core 350 before being directed to the dual inlet turbine 406 and then through the second WHR core 370.

[0088] The high pressure working fluid path 404 is configured to receive heat from exhaust gas or other types of fluids or gases at a higher pressure than the source of heat used in the low pressure working fluid path 402.

[0089] Both working fluid from the low-pressure working fluid path 402 and working fluid from the high-pressure working fluid path 404 are directed to a dual-inlet turbine 406, which includes a first inlet in fluid communication with the low-pressure working fluid path 402 and a second inlet in fluid communication with the high-pressure working fluid path 404. The dual-inlet turbine 406 is configured to receive both low-pressure working fluid and high-pressure working fluid and convert thermal energy of these working fluids into mechanical work.

[0090] Figure 5 is an illustration of a WHR system 500 including a two-stage dual-core CAC system 300 in parallel, according to particular embodiments. As shown, the WHR system 500 includes a low-pressure working fluid path 502 and a high-pressure working fluid path 504. The low-pressure working fluid path 502 is configured to receive heat from a source that is typically at a relatively lower temperature (e.g., 50 to 150 degrees Celsius) compared to a source used on the high-pressure working fluid path 504 and is in fluid communication with the two-stage dual-core CAC system 300 arranged in parallel. The parallel arrangement refers to a manner in which working fluid can be directed through the two-stage dual-core CAC system 300 (e.g., working fluid can be independently directed through one or both of the low-pressure dual-core CAC 310 and the high-pressure dual-core CAC 330).

[0091] The low-pressure dual-core CAC 310 is in fluid communication with the low-pressure working fluid path 502 and the high-pressure dual-core CAC 330 is in fluid communication with the high-pressure working fluid path 504. A first valve 508 is in fluid communication with the low-pressure working fluid path 502 and is operable to direct working fluid through the low-pressure working fluid path 502 or prevent working fluid from flowing through the low-pressure working fluid path 502. A second valve (not shown) can be positioned in or on the high-pressure working fluid path 504 and is operable to direct working fluid through the high-pressure working fluid path 504 or prevent working fluid from flowing through the high-pressure working fluid path 504. Thus, based on the arrangement of the first valve 508 and the second valve, working fluid can be directed through one or both of the first WHR core 350 and the second WHR core 370 or working fluid can be prevented from flowing through both of the first WHR core 350 and the second WHR core 370.

[0092] The decision of whether to allow working fluid to pass through either of the first WHR core 350 and the second WHR core 370, neither of the first WHR core 350 and the second WHR core 370, or both of the first WHR core 350 and the second WHR core 370 can be based on the temperature of the charge air as it exits the high-pressure dual-core CAC 330. For example, in some embodiments, working fluid can flow through both the first WHR core 350 and the second WHR core 370. The temperature of the charge air as it exits the high-pressure dual-core CAC 330 can be lower than the target intake air temperature. In this case, one or both of the first valve 508 and the second valve can be operated to prevent working fluid from flowing through one or both of the first WHR core 350 and the second WHR core 370 to increase the temperature of the charge air as it exits the high-pressure dual-core CAC 330. As another example, in some embodiments, working fluid can flow through only the second WHR core 370 (e.g., the first valve 508 is closed to prevent working fluid from flowing through the first WHR core 350). The temperature of the charge air as it exits the high-pressure dual-core CAC 330 can be higher than the target intake air temperature. In this example embodiment, the first valve 508 can be opened to allow working fluid to flow through the first WHR core 350 to reduce the temperature of the charge air exiting the high-pressure dual-core CAC 330 to the target intake air temperature.

[0093] Working fluid from the low-pressure working fluid path 502 and working fluid from the high-pressure working fluid path 504 are both directed to a dual-inlet turbine 506. The dual-inlet turbine includes a first inlet in fluid communication with the low-pressure working fluid path 502 and a second inlet in fluid communication with the high-pressure working fluid path 504. The dual-inlet turbine 506 is configured to receive both low-pressure working fluid and high-pressure working fluid and convert thermal energy of these working fluids into mechanical work.

[0094] IV. Three-Core CAC System

[0095] Figures 6-7 FIGS. 1 and 2 illustrate a three-core CAC system 600 and a WHR system 700 including the three-core CAC system 600, respectively, according to certain embodiments. As shown, the three-core CAC system 600 includes a cooling fluid core 610, a preheater core 630, a superheater core 650, and a WHR boiler 660.

[0096] The cooling fluid core 610 includes a cooling fluid inlet 612 coupled to a cooling fluid outlet 614 via a cooling fluid conduit (not shown). The cooling fluid inlet 612 is in fluid communication with a cooling fluid source that provides cooling fluid (e.g., water, coolant, refrigerant, etc.) to the cooling fluid inlet 612. The cooling fluid core 610 also includes a third air inlet (not shown) coupled to a third air outlet 616 by a third air conduit, where the third air outlet 616 is in fluid communication with an air intake of the engine (or, in some embodiments, in fluid communication with the air intake via an additional compression stage). In some embodiments, the cooling fluid conduit and the third air conduit are adjacent to one another such that at least some heat from the charge air is absorbed by the cooling fluid, thereby reducing the temperature of the charge air and increasing the temperature of the cooling fluid.

[0097] The preheater core 630 includes a first working fluid inlet 632 coupled to a first working fluid outlet 634 via a first working fluid conduit (not shown). The first working fluid inlet 632 is in fluid communication with the low pressure working fluid path 702 such that working fluid in the low pressure working fluid path 702 is directed to the first working fluid inlet 632. The preheater core 630 also includes a second air inlet 636 coupled to a second air outlet 638 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 one another such that at least some heat from the charge air is absorbed by the working fluid, thereby reducing the temperature of the charge air and increasing the temperature of the working fluid.

[0098] The superheater core 650 includes a second working fluid inlet 652 coupled to a second working fluid outlet 654 via a second working fluid conduit (not shown), where the second working fluid inlet 652 is in fluid communication with the first working fluid outlet 634. The superheater core 650 also includes a first air inlet 656 and a first air outlet 658 coupled to the first air inlet 656 by a first air conduit, where the first air outlet is in fluid communication with the second air inlet. The first air inlet 656 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 one another such that at least some heat from the charge air is absorbed by the working fluid, thereby reducing the temperature of the charge air and increasing the temperature of the working fluid.

[0099] The WHR boiler 660 is positioned between the first working fluid outlet 634 and the second working fluid inlet 652 and is configured to heat the working fluid, causing the working fluid to partially or fully boil.

[0100] In operation, the three-core CAC system 600 is configured to receive charge air from a turbocharger at the first air inlet 656, where the charge air is at an elevated temperature (e.g., approximately 300-350 degrees Fahrenheit). The three-core CAC system 600 is also configured to receive working fluid from the low-pressure working fluid path 702 at a low temperature (e.g., approximately 40-60 degrees Fahrenheit) at the first working fluid inlet 632, and to receive cooling fluid at a low temperature (e.g., approximately 40-60 degrees Fahrenheit) at the cooling fluid inlet 612.

[0101] As the charge air flows through the first, second, and third air conduits, 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 and second working fluid conduits, increases. At the third air outlet 616, the temperature of the air has substantially reached the target intake air temperature and is provided to the intake manifold (or, in some embodiments, to the intake manifold via an additional compression stage or compressor inlet).

[0102] In this example embodiment, the WHR boiler 660 is used to heat the working fluid prior to the working fluid entering the superheater core 650. Heating the working fluid as described allows the charge air to be cooled as it flows through the superheater core 650, and increases the thermal energy of the working fluid as heat from the charge air is transferred to the working fluid. As described above, increasing the thermal energy of the working fluid provides for efficient waste heat recovery, and provides for greater mechanical power from the WHR system 700 as compared to not using the WHR boiler 660.

[0103] The WHR system 700 includes a low-pressure working fluid path 702 and a high-pressure working fluid path 704, with the three-core CAC system 600 positioned along the low-pressure working fluid path 702. Working fluid from the low-pressure working fluid path 702 is directed from the three-core CAC system 600 to a dual-inlet turbine 706. The dual-inlet turbine 706 is configured to receive both low-pressure working fluid and high-pressure working fluid, and to convert the thermal energy of these working fluids into mechanical power.

[0104] V. Configuration of Example Embodiments

[0105] While the specification contains many specific implementation details, these should not be construed as limiting the scope of what can be claimed, but as merely providing description of features that are particular implementations. Certain features that are, for clarity, described under separate headings should be considered individual implementations, of which an individual implementation can include fewer than all of the described features. Conversely, where various features are described as being used in certain combinations, individual implementations can employ a sub-combination or variation of those combinations. Further, to the extent that features can be described as being implemented in a certain way, even though that implementation can not have been claimed, an individual implementation can employ a variation on that implementation that was originally claimed and the general principles of that implementation can be applied to any feature or claim.

[0106] As used herein, the terms "substantially," "about," 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 present disclosure pertains. It is to be understood that such terms are intended to permit for variations from the absolute specific frequency, duration, level, position, etc. within a range that does not materially affect the expected performance of the present disclosure. Accordingly, such terms can be construed as indicating that only within a "preferred range" of values should be used when implementing the present disclosure. However, more preference is given to a closer rather than a more distant value, within measured ranges.

[0107] The term "coupled" or similar terms as used herein refer to two components being linked to one another directly or indirectly. Such linking can be fixed (e.g., permanent) or moveable (e.g., removable or releasable). Such linking can be achieved by two components being integrally formed as a single unit with one another or two components being integrally formed as a single unit with any additional intermediate components, by two components being attached to one another or two components being attached to one another with any additional intermediate components.

[0108] It is important to note that the construction and arrangement of the systems shown in the various example implementations is illustrative only and not restrictive in character. All changes and modifications that come within the spirit and / or scope of the described implementations are desired to be protected. It should be understood that some features can not be necessary, and implementing the described implementations lacking various features can be contemplated as within the scope of the application, the scope being defined by the claims appended hereto. When the language "a portion" is used, the item can include a portion and / or the entire item, unless specifically stated to the contrary.

[0109] Furthermore, the term "or" is used in the inclusive sense (and not the exclusive sense) so that when used, for example, in a conjunctive "or" manner, the conjunction "or" is intended to mean one, some, or all of the associated listed items. Conjunctive language such as the phrase "at least one of X, Y, and Z," unless specifically stated otherwise, is understood to mean that the item, term, etc. can be X, Y, Z, any one of X, Y, and Z, X and Y, X and Z, Y and Z, or X, Y, and Z (i.e., any combination of X, Y, and Z). Thus, unless specifically stated otherwise, such conjunctive language is not generally intended to mean that certain embodiments require at least one of X, at least one of Y, and at least one of Z each to exist, although such conjunctive language, depending on the context, can be so understood.

[0110] While several embodiments have been described in detail, those skilled in the art will recognize that the teachings herein can be applied in a multitude of embodiments and can be used for other applications as well. Moreover, the logical steps described in the exemplary embodiments can be implemented by computer software, hardware, or any combination of hardware and software suitable for this purpose. Accordingly, the term "processor" as used herein is intended to include any processing device, such as one that contains multiple processing units, and is intended to include devices that have more than one processing unit. Furthermore, the above-described effects and advantages are intended to be illustrative and not exhaustive. Numerous other effects and advantages will be apparent to those of ordinary skill in the art.

Claims

1. A waste heat recovery system for an engine system, comprising: A first multi-core charge air cooler in fluid communication with a working fluid path of the waste heat recovery system, the first multi-core charge air cooler comprising: a first waste heat recovery core; and A first cooling fluid core, the first cooling fluid core comprising: a first cooling fluid inlet in fluid communication with a cooling fluid source; a first cooling fluid conduit fluidly coupled to the first cooling fluid inlet and a first cooling fluid outlet, the first cooling fluid conduit configured to direct cooling fluid from the first cooling fluid inlet to the first cooling fluid outlet; and a first air duct adjacent to the first cooling fluid duct, the first air duct being in fluid communication with an air inlet and an air outlet, the first air duct being configured to direct air supplied by an air source from the air inlet to the air outlet, the air outlet being in fluid communication with an air intake of an engine or a compressor inlet of the engine; and A second multi-core charge air cooler in fluid communication with the working fluid path, the second multi-core charge air cooler comprising: a second waste heat recovery core; and A second cooling fluid core, the second cooling fluid core comprising: a second cooling fluid inlet in fluid communication with the cooling fluid source; a second cooling fluid conduit fluidly coupled to the second cooling fluid inlet and the second cooling fluid outlet, the second cooling fluid conduit configured to direct the cooling fluid from the second cooling fluid inlet to the second cooling fluid outlet; and A second air duct is adjacent to the second cooling fluid duct and in fluid communication with the first air duct and in fluid communication with the air intake of the engine.

2. The waste heat recovery system according to claim 1, wherein: The first waste heat recovery core comprises: a first working fluid inlet configured to receive the working fluid from the working fluid path; a first working fluid conduit fluidly coupled to the first working fluid inlet and a first working fluid outlet, the first working fluid conduit being configured to direct the working fluid from the first working fluid inlet to the first working fluid outlet; and an additional air duct adjacent to the first working fluid duct, the additional air duct being in fluid communication with an additional air inlet and an additional air outlet, and the additional air duct being configured to direct air from the additional air inlet to the additional air outlet, the additional air inlet being in fluid communication with the air source, and the additional air outlet being in fluid communication with the air inlet.

3. The waste heat recovery system according to claim 2, wherein: The further air duct is configured to transfer heat from the air to the first working fluid duct, thereby reducing the temperature of the air from a first temperature to a second temperature.

4. The waste heat recovery system according to claim 3, wherein: The first air duct is configured to transfer heat from the air to the first cooling fluid duct, thereby reducing the temperature of the air from the second temperature to a third temperature.

5. The waste heat recovery system according to any one of claims 2 to 4, wherein: The second waste heat recovery core comprises: a second working fluid inlet configured to receive the working fluid from the first working fluid outlet; a second working fluid conduit fluidly coupled to the second working fluid inlet; and A third air conduit is adjacent to the second working fluid conduit and is in fluid communication with the air outlet.

6. The waste heat recovery system according to claim 5, further comprising: a low-pressure working fluid path, the second multi-core charge air cooler being located within the low-pressure working fluid path; a high-pressure working fluid path; and A dual-input turbine is configured to receive working fluid from the low-pressure working fluid path and the high-pressure working fluid path.

7. The waste heat recovery system according to claim 5, wherein: The second working fluid conduit is fluidly coupled to a second working fluid outlet, the second working fluid conduit being configured to direct the working fluid from the second working fluid inlet to the second working fluid outlet.

8. The waste heat recovery system according to claim 5, wherein: The third air duct is in fluid communication with a third air inlet and a third air outlet, and the third air duct is configured to direct air from the third air inlet to the third air outlet. The third air inlet is in fluid communication with the air outlet.

9. The waste heat recovery system according to claim 8, wherein: The second air duct is in fluid communication with a fourth air inlet and a fourth air outlet, and the second air duct is configured to direct air from the fourth air inlet to the fourth air outlet, the fourth air inlet being in fluid communication with the third air outlet, and the fourth air outlet being in fluid communication with the air intake of the engine.

10. A waste heat recovery system for an engine system, comprising: A first multi-core charge air cooler in fluid communication with the low-pressure working fluid path, the first multi-core charge air cooler comprising: A first waste heat recovery core, the first waste heat recovery core comprising: a first working fluid conduit fluidly coupled to a first working fluid inlet and a first working fluid outlet, the first working fluid conduit being configured to direct working fluid from the first working fluid inlet to the first working fluid outlet; and a first air duct adjacent to the first working fluid duct, the first air duct being in fluid communication with an air inlet and an air outlet, and the first air duct being configured to direct air from the air inlet to the air outlet, the air inlet being in fluid communication with an air source, the air outlet being in fluid communication with an air intake of an engine or a compressor inlet of the engine; and A first cooling fluid core, the first cooling fluid core comprising: a first cooling fluid inlet in fluid communication with a cooling fluid source; a first cooling fluid conduit fluidly coupled to the first cooling fluid inlet and a first cooling fluid outlet, the first cooling fluid conduit configured to direct cooling fluid from the first cooling fluid inlet to the first cooling fluid outlet; and a second air duct adjacent to the first cooling fluid duct, the second air duct being in fluid communication with the first air duct and the air outlet; and A second charge air cooler in fluid communication with the high pressure working fluid path, the second charge air cooler comprising: A second waste heat recovery core, the second waste heat recovery core comprising: a second working fluid inlet configured to receive working fluid from the high-pressure working fluid path; a second working fluid conduit; and a third air conduit adjacent to the second working fluid conduit and in fluid communication with the air outlet; and A second cooling fluid core, the second cooling fluid core comprising: a second cooling fluid inlet in fluid communication with the cooling fluid source; a second cooling fluid conduit fluidly coupled to the second cooling fluid inlet; and A fourth air duct is adjacent to the second cooling fluid duct and in fluid communication with the third air duct and in fluid communication with the air intake of the engine. 11 . The waste heat recovery system of claim 10 , further comprising a dual-input turbine configured to receive working fluid from the low-pressure working fluid path and the high-pressure working fluid path.

12. The waste heat recovery system according to claim 10, wherein: The second working fluid conduit is fluidly coupled to the second working fluid inlet and the second working fluid outlet, the second working fluid conduit being configured to direct the working fluid from the second working fluid inlet to the second working fluid outlet.

13. The waste heat recovery system according to claim 10, wherein: The third air duct is in fluid communication with a third air inlet and a third air outlet, and the third air duct is configured to direct air from the third air inlet to the third air outlet. The third air inlet is in fluid communication with the air outlet.

14. The waste heat recovery system according to claim 13, wherein: The fourth air duct is in fluid communication with a fourth air inlet and a fourth air outlet, and is configured to direct air from the fourth air inlet to the fourth air outlet, the fourth air inlet being in fluid communication with the third air outlet, and the fourth air outlet being in fluid communication with the air intake of the engine.

15. The waste heat recovery system according to claim 10, wherein: The second cooling fluid conduit is fluidly coupled to the second cooling fluid inlet and the second cooling fluid outlet, the second cooling fluid conduit being configured to direct cooling fluid from the second cooling fluid inlet to the second cooling fluid outlet.

16. An engine system comprising: A waste heat recovery system, comprising: a first multi-core charge air cooler in fluid communication with the first working fluid path, the first cooling fluid path, and the air source, the first multi-core charge air cooler including at least a first waste heat recovery core and a first cooling fluid core; a second multi-core charge air cooler in fluid communication with the second working fluid path, the second cooling fluid path, and the air source, the second multi-core charge air cooler including at least a second waste heat recovery core and a second cooling fluid core; and A first flow control valve selectively directs a portion of the working fluid through the first working fluid path and a remaining portion of the working fluid through the second working fluid path. 17 . The engine system of claim 16 , further comprising a second flow control valve that selectively directs cooling fluid through the first cooling fluid path. 18 . The engine system of claim 17 , further comprising a third flow control valve that selectively directs the cooling fluid through the second cooling fluid path.

19. The engine system of claim 16, further comprising: a first air duct extending from a first air inlet of the first multi-core charge air cooler to a first air outlet of the first multi-core charge air cooler; and A low-pressure compressor is in fluid communication with the air source and the first air conduit.

20. The engine system of claim 19, further comprising: a second air duct extending from a second air inlet of the second multi-core charge air cooler to a second air outlet of the second multi-core charge air cooler; and A high pressure compressor is in fluid communication with the first air outlet and the second air inlet.

21. The engine system according to any one of claims 16-20, wherein: The first working fluid path includes a low-pressure working fluid, and the second working fluid path includes a high-pressure working fluid.

22. The engine system of claim 21, further comprising a dual-inlet turbine in fluid communication with the first working fluid path and the second working fluid path, the dual-inlet turbine configured to receive the low-pressure working fluid and the high-pressure working fluid.

23. The engine system of any one of claims 16-20 and 22, further comprising an additional valve in fluid communication with the second working fluid path, the additional valve configured to selectively direct a portion of the working fluid through the second working fluid path.

24. A waste heat recovery system for an engine system, comprising: a first multi-core charge air cooler in fluid communication with the working fluid path and a source of compressed air, the first multi-core charge air cooler configured to direct compressed air from a first air inlet to a first air outlet and to direct working fluid from the first working fluid inlet to a first working fluid outlet; a second multi-core charge air cooler in fluid communication with the working fluid path and the source of compressed air, the second multi-core charge air cooler being configured to direct the compressed air from a second air inlet to a second air outlet and to direct the working fluid from the second working fluid inlet to a second working fluid outlet, the second air inlet being in fluid communication with the first air outlet, and the second working fluid inlet being in fluid communication with the first working fluid outlet; and a third multi-core charge air cooler in fluid communication with a cooling fluid path and the compressed air source, the third multi-core charge air cooler being configured to direct the compressed air from a third air inlet to a third air outlet, and to direct cooling fluid from a first cooling fluid inlet to a first cooling fluid outlet, the third air inlet being in fluid communication with the second air outlet, and the third air outlet being in communication with an air intake of the engine system.

25. The waste heat recovery system of claim 24, further comprising a boiler in fluid communication with the first multi-core charge air cooler and the second multi-core charge air cooler, the boiler configured to receive the working fluid from the second working fluid outlet and direct the working fluid to the first working fluid inlet.

26. The waste heat recovery system according to claim 25, wherein: The boiler partially or fully boils the working fluid before directing the working fluid to the first working fluid inlet.

27. The waste heat recovery system according to claim 25, wherein: The working fluid is a low-pressure working fluid.

28. The waste heat recovery system according to claim 27, further comprising a turbine configured to receive the low-pressure working fluid and the high-pressure working fluid and convert the first thermal energy of the low-pressure working fluid and the second thermal energy of the high-pressure working fluid into mechanical work.

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