Fluid heater

Abstract

A fluid heater is provided and includes a conduit, an insert, and a heating element. The conduit is for conveying a fluid flow and has an inner surface and an outer surface. An insert is positioned inside the conduit and includes a plurality of fins extending radially inward relative to the conduit and a core member occupying at least a portion of a radially inward cross-sectional area of the plurality of fins to drive a portion of the fluid to flow around the core member and engage the plurality of fins. The heating element is energizable to heat the fluid.

Description

Technical Field

[0001] The present disclosure generally relates to the field of fluid heaters and, more particularly, to a liquid fluid heater for use in an electric vehicle. Background Art

[0002] Fluid heaters are known in electric vehicles (EVs) for the purpose of heating components that ultimately circulate through the EV and that need to be heated for performance reasons, such as the coolant of the vehicle's battery pack. Generally, there continues to be a focus on improving the performance and reliability of these devices and at least partially addressing some of the other problems that have existed with coolant heaters that have been used or proposed in the past, such as high cost. Summary of the Invention

[0003] In one aspect, a fluid heater is provided and the fluid heater includes a conduit, an insert, and a heating element. The conduit is for conveying a fluid flow and has an inner surface and an outer surface. The insert is positioned inside the conduit and includes a plurality of fins and a core member, the plurality of fins extending radially inwardly relative to the conduit, the core member occupying at least a portion of the radially inward cross-sectional area of the plurality of fins so as to drive a portion of the fluid to flow around the core member and engage the plurality of fins. The heating element is energizable to heat the fluid.

[0004] In another aspect, a fluid heater is provided and the fluid heater includes a conduit and a heating element. The conduit is for conveying a fluid flow and has an inner surface and an outer surface. An insert is positioned inside the conduit and includes a core member and at least one fin extending radially. The at least one fin is at least one helical fin connected to the core member and spirally extending around the core member. The core member occupies at least a portion of the radially inward cross-sectional area of the at least one helical fin so as to drive a portion of the fluid to flow around the core member and engage the at least one helical fin. The heating element is energizable to heat the fluid.

[0005] In addition to the above aspects, other aspects of the present disclosure are considered inventive and superior to the prior art. Brief Description of the Drawings

[0006] The foregoing and other aspects of the invention will be better understood with reference to the accompanying drawings, which are as follows:

[0007] Figure 1 is a side view of a vehicle including a fluid heater according to an embodiment of the present disclosure.

[0008] Figure 2 is for Figure 1 a schematic diagram of the thermal management system for the vehicle shown in

[0009] Figure 3 is asFigure 2 Perspective view of a fluid heater that is part of the thermal management system shown in

[0010] Figure 4 is Figure 3 Exploded perspective view of the fluid heater shown in

[0011] Figure 5A is for Figure 3 Exploded perspective view of an insert for the fluid heater shown in

[0012] Figure 5B is for Figure 3 Enlarged perspective view of a part of an insert for the fluid heater shown in

[0013] Figure 5C is for Figure 3 Enlarged perspective view of another part of an insert for the fluid heater shown in

[0014] Figure 6A is Figure 3 Exploded perspective view of a part of the fluid heater shown in

[0015] Figure 6B is Figure 6A Perspective view of a part of the fluid heater shown in

[0016] Figure 7 is Figure 6A Another perspective view of a part of the fluid heater shown in

[0017] Figure 8 is from Figure 3 Perspective view of an element with an optional circumferential gap from the insert of the fluid heater shown in

[0018] Figure 9 is of Figure 8 End view of the elements shown in at several stacked positions

[0019] Figure 10 is Figure 8 Perspective view of an element with an alternative optional circumferential gap shown in

[0020] Figure 11 is a perspective view showing an alternative insert for use in the fluid heater shown in Figure 3

[0021] Figure 12 is inserted into the duct of the fluid heater according to Figure 3 shown in Figure 11 End view of the insert shown in

[0022] Figure 13 is an end view of an alternative insert inserted into a conduit of a fluid heater as shown in Figure 3 .

[0023] Figure 14 is Figure 13 a perspective view of the insert as shown in

[0024] Figure 15 is an image of fluid in a fluid heater, with regions indicating relative amounts of fluid flow.

[0025] Figure 16 is a sectional perspective view of a conduit, heating element, conduit housing, and inlet and outlet members of a fluid heater as shown in Figure 3 .

[0026] Figure 17 is a sectional plan view of a conduit, conduit housing, inlet and outlet members, and alternative heating elements that may be used.

[0027] Figure 18 is a plan view of a higher output configuration that uses two heating elements to heat fluid.

[0028] Figure 19 is a perspective view of an alternative embodiment of an insert for a fluid heater as shown in Figure 2 , the alternative embodiment including alternative optional circumferential gaps and expansion members.

[0029] Figure 20 is Figure 19 an end view of the insert as shown in DETAILED DESCRIPTION

[0030] Explanation

[0031] For simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. Further, numerous specific details are set forth to provide a thorough understanding of one or more embodiments described herein. However, one of ordinary skill in the art will understand that the embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the embodiments described herein. First, it should be understood that although exemplary embodiments are illustrated in the figures and described below, the principles of the present disclosure may be implemented using any number of techniques, whether currently known or not. The present disclosure should in no way be limited to the exemplary embodiments and techniques illustrated in the figures and described below.

[0032] Unless the context indicates otherwise, the various terms used throughout this specification can be read and understood as follows: The "or" used throughout is inclusive, as if written "and / or"; the singular articles and pronouns used throughout include their plural forms, and the plural articles and pronouns used throughout include their singular forms; similarly, gender pronouns include their corresponding pronouns, so pronouns should not be understood as restricting anything described herein to use, implementation, execution, etc. by a single gender; "exemplary" should be understood as "illustrative" or "by way of example" and not necessarily as "preferred" to other embodiments. Further definitions of terms may be set forth herein; as will be understood by reading this specification, these definitions may apply to prior and subsequent instances of those terms. It will also be noted that, unless otherwise expressly stated or unless it is understood to clearly have to mean "one", the use of the term "a" or "an" will be understood to mean "at least one" in all cases.

[0033] Without departing from the scope of the present disclosure, modifications, additions, or omissions may be made to the systems, devices, and methods described herein. For example, components of the systems and devices may be combined or separated. Additionally, the operations of the systems and devices disclosed herein may be performed by more, fewer, or other components, and the methods described may include more, fewer, or other steps. Additionally, the steps may be performed in any suitable order. As used in this document, "each" refers to each member of a group or each member of a subgroup of a group.

[0034] As used in this document, when describing the relationship between two connected parts, "attached" includes both the case where the two connected parts are "directly attached" and the two connected parts are in contact with each other, and the case where the connected parts are "indirectly attached" and are not in contact with each other but are connected by one or more other intervening parts.

[0035] As used in this document, unless the context clearly dictates otherwise, terms describing the relative position of elements such as "top", "upper", "bottom", "lower", or other similar terms will be understood to refer to the placement of the described element during the use of the device of which it is a part. It should be understood that, for example, the above placement of an element can still be considered its placement even when the object of which it is a part is in some position other than the position where it will be used. By way of example, if reference is made to a device having an upper member, it should be understood that, unless the context clearly dictates otherwise, the upper member is described as having an upper position when the device of which it is a part is in use or in a use position. In addition to this example, it should be understood that the upper member of the aforementioned object can still be considered its upper member even when the object is lying on its side for storage, or for transportation, or for other reasons.

[0036] "Memory" refers to a non-transitory tangible computer-readable medium for storing information (e.g., data or data structures) in a processor-readable format and / or instructions (e.g., computer code or software program or module) that can be read and executed by a processor to implement an algorithm. The term "memory" includes a single device or multiple physically separated and operatively connected devices, although the term is used in the singular. Non-limiting types of memory include solid-state semiconductors, optical, magnetic, and magneto-optical computer-readable media. Examples of memory technologies include optical discs such as compact discs (CD-ROMs) and digital versatile discs (DVDs), magnetic media such as floppy disks, magnetic tapes, or cassette tapes, and solid-state semiconductor random access memory (RAM) devices, read-only memory (ROM) devices, electrically erasable programmable read-only memory (EEPROM) devices, flash memory devices, memory chips, and combinations of the above. Memory can be non-volatile or volatile. Memory can be physically attached to the processor or remote from the processor. Memory can be removable or non-removable from a system including the processor. Memory can be operatively connected to the processor such that it can be accessed by the processor. The instructions stored in the memory can be based on a variety of programming and / or markup languages known in the art, non-limiting examples of which include C, C++, C#, Python TM , MATLAB TM , Java TM , JavaScript TM , Perl TM , PHP TM , SQL TM , Visual Basic TM , Hypertext Markup Language (HTML), Extensible Markup Language (XML), and combinations of the above. The instructions stored in the memory can also be implemented by configuration settings for fixed-function devices, gate arrays, or programmable logic devices.

[0037] "Processor" refers to one or more electronic hardware devices capable of reading and executing instructions stored in memory to perform operations on data, which can be stored in memory or provided in the form of a data signal. The term "processor" includes a single device or multiple physically separated and operatively connected devices, although the term is used in the singular. Multiple processors can be arranged or distributed. Non-limiting examples of processors include integrated circuit semiconductor devices and / or processing circuit devices known as computers, servers or terminals with single-processor or multi-processor architectures, microprocessors, microcontrollers, microcontroller units (MCUs), central processing units (CPUs), field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), digital signal processors, and combinations of the foregoing.

[0038] Any method, application, or module described herein can be implemented using computer-readable / executable instructions that can be stored by a memory or otherwise preserved and executed by a processor. Aspects of the present invention can be described with reference to the flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present invention. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor, such that the processor and the memory storing the instructions executed by the processor together constitute a machine for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0039] The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram can represent a module, segment, or portion of code, which includes one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions noted in the blocks may not occur in the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending on the functionality involved. It should also be noted that each block in the block diagrams and / or flowchart illustrations, and combinations of blocks in the block diagrams and / or flowchart illustrations, can be implemented by a dedicated hardware-based system that performs the specified functions or actions, or by a combination of dedicated hardware and computer instructions.

[0040] The embodiments of the present invention described herein are exemplary (e.g., in terms of materials, shapes, dimensions, and construction details) and are not limited by the appended claims and any modifications thereto. Those skilled in the art will understand that there are more possible alternative implementations and modifications, and the following examples are merely illustrative of one or more implementations. Therefore, the scope of the present invention is limited only by the appended claims and any modifications thereto.

[0041] Any reference to up, down, top, bottom, etc. is intended to refer to the orientation of a particular element during the use of the claimed subject matter and not necessarily to its orientation during transportation or manufacture. For example, the upper surface of an element can still be considered the upper surface of the element even when the element is lying on its side.

[0042] The terms "comprises" and "comprising" and their various variations (such as "including") shall be understood to be inclusive and open-ended, rather than exclusive. This means that if element A comprises or includes element B, it should be understood that in addition to comprising or including element B, element A may also comprise or include other elements. The term "has" and its various variations shall also be understood to be open-ended in the same manner as "comprises" and "comprising". These terms should not be construed as excluding the presence of other features, steps, or components.

[0043] Brief Description of the Vehicle and the Thermal Management System

[0044] Reference Figure 1 , Figure 1 shows a vehicle 10, which may be an electric vehicle. The term "electric vehicle" is intended to include any vehicle that includes a battery pack 12 and an electric motor 13 that drives one or more wheels 15 of the vehicle 10. In addition to the battery pack 12, the vehicle 10 may also include any other suitable type of energy storage device. The electric motor 13 may operate alone or may be one of a plurality of electric motors. Additionally, the vehicle 11 may include other types of power plants, such as an internal combustion engine.

[0045] Figure 1 The vehicle 10 shown in [reference] is an automobile. However, it should be understood that the vehicle 10 may be any other suitable type of vehicle, such as a minivan, pickup truck, commercial van or truck, bus, SUV, ATV, tracked or wheeled construction vehicle, such as an excavator, backhoe loader, bulldozer or skid steer loader. The vehicle may also be a boat or an aircraft. The vehicle may be remotely operated or operated by a driver. The vehicle may be fully or partially autonomous, or not autonomous. The vehicle may carry one or more persons and / or cargo, or may not carry anything. In Figure 1 the example vehicle 10 shown, the vehicle 10 carries people and optional cargo in the vehicle compartment 18 and may also carry cargo in the trunk shown at 19.

[0046] In Figure 1 the vehicle 10 is shown plugged into a charging station 16.

[0047] Reference Figure 2 , Figure 2FIG. 0 shows a schematic diagram of a simple example of a thermal management system 20 for a vehicle 10. The thermal management system 20 is configured to heat and cool a plurality of thermal loads shown at 22 in the vehicle 10 (i.e., for thermal management of a plurality of thermal loads 22 in the vehicle 10). The thermal loads 22 can include, for example, a first thermal load 22 that can be a battery pack 12, a second thermal load 22 that can be an electric motor 13 and associated power electronics, and a third thermal load 22 that can be a vehicle cabin shown at 18.

[0048] Alternatively, the thermal load 22 can be any other suitable element of the vehicle 10 that requires additional heat or removal of heat for temperature regulation.

[0049] The thermal management system 20 includes a duct system 24 for delivering fluid to and from the plurality of thermal loads 22. The thermal management system 20 also includes a fluid propeller 26 for driving fluid flow through the duct system 24. In embodiments where the fluid is a liquid, such as a coolant or a dielectric fluid, the fluid propeller 26 can be a pump, such as a centrifugal pump. In embodiments where the fluid is a gas, such as a refrigerant, the fluid propeller 26 can be a compressor. The thermal management system 20 also includes a fluid heater 28 and a fluid cooler 30. The fluid heater 28 is configured to heat the fluid in order to heat one or more of the thermal loads 22. The fluid cooler 30 is configured to cool the fluid in order to cool one or more of the thermal loads 22. The duct system 24 can include one or more control valves (not shown) for controlling which thermal loads receive fluid flow and which do not.

[0050] Figure 2 The thermal management system 20 shown in FIG. is merely an example. Any other suitable thermal management system can be provided for the thermal management of the plurality of thermal loads 22.

[0051] General Description of Fluid Heater

[0052] Referring to Figure 3 and Figure 4 , Figure 3 and Figure 4 show a perspective view and an exploded view of a fluid heater 28 according to an embodiment of the present disclosure, respectively. The fluid heater 28 includes a duct 32 for conveying a fluid flow, an insert 34, and a heating element 36. The duct 32 is for conveying a fluid flow and has an inner surface 38 and an outer surface 40 ( Figure 16 ). The insert 34 is positioned inside the duct 32 ( Figure 16 ). Referring to Figure 5A , Figure 5B and Figure 5C, the insert 34 includes a plurality of fins 42 that extend radially inwardly relative to the conduit 32 and a core member 44 that occupies at least a portion of the radially inward cross-sectional area of the plurality of fins 42 so as to drive a portion of the fluid to flow around the core member 44 and engage the plurality of fins 42.

[0053] In Figures 5A to 5C In the illustrated embodiment, the insert 34 further includes an outer peripheral member 46 positioned to engage the inner surface 38 of the conduit 32. The plurality of fins 42 are (optionally integrally) connected to the outer peripheral member 46 and extend radially inwardly from the outer peripheral member 46. The combination of the fins 42 and the outer peripheral member 46 may be referred to as a fin carrier 47. Each fin 42 has a radially inner end 48. The core member 44 may be separate from the plurality of fins 42 and may engage the plurality of fins 42 in any suitable manner so as to stabilize the radially inner ends 48 of the plurality of fins 42. The core member 44 may include, for example, a plurality of longitudinal slots 50 for receiving the radially inner ends 48 of the plurality of fins 42. Each longitudinal slot 50 has a blind end 52 at a first end 54 of the core member 44 and an open end 56 at a second end 58 of the core member 44. The fluid heater 28 further includes a core locking member 60 that mechanically engages the second end 58 of the core member 44 to prevent the core member 44 from being removed from the fin carrier 47.

[0054] In the illustrated embodiment, the core locking member 60 includes a plurality of slot protrusions 62 that extend into the plurality of longitudinal slots 50, and the core member 44 further includes a plurality of circumferential slot side paths 64 that extend away from the plurality of slots 50 in the circumferential direction.

[0055] In this embodiment, to install the core member 44 to the fins 42, the fin carrier 47 is slid over the core member 44, where the fins 42 slide along the slots 50 until the fins 42 engage the blind ends 52 of the slots 50. The core locking member 60 can be slid onto the core member 44 by sliding the slot protrusions 62 along the slots 50 until reaching the circumferential slot side paths 64. Then, the core locking member 60 is rotated circumferentially until the slot protrusions 62 are at least partially captured in the circumferential slot side paths 64. At this time, the core member 44 is captured on the fins 42 and prevents the core member 44 from being removed from the fin carrier 47.

[0056] The conduit 32 can be made of any suitable material, such as a thermally conductive material such as metal. This allows the conduit 32 to better conduct heat from the heating element 36 to the fluid.

[0057] In some embodiments, the conduit 32 is made of stainless steel. The insert 34 can be made of any suitable material. In some embodiments, the insert 34 can be made of several materials. For example, the fin carrier 47 can be made of any suitable material, such as a metal, and more specifically, such as stainless steel, to help conduct heat from the conduit 32 to more of the fluid flowing through the conduit 32. The core member 44 can be made of any suitable material. An example of a suitable material is a polymeric material such as a nylon, which makes the core member 44 lighter than it would be if the core member were made of some other material, such as many metals. In addition, a polymeric material having a relatively low thermal conductivity, such as nylon, prevents heat from being conducted out of the fins 42. This allows the fins 42 to be at a higher temperature than they would be if a large amount of heat were conducted into the core member 44. The higher temperature of the fins 42 allows the fins 42 to transfer heat to the fluid better. However, the core member 44 can be made of other suitable materials, other suitable materials including any suitable metal.

[0058] Before inserting the fin carrier 47 into the conduit 32, a suitable lubricant can be applied to the inner surface 38 of the conduit 32 and / or the outer surface of the fin carrier 47 (shown at 68 in Figure 5A ). Any suitable lubricant can be used. For example, the lubricant can be a grease, such as a bearing grease. In some embodiments, the lubricant can be the fluid itself. For example, it has been seen that ethylene glycol has lubricating properties. Thus, in embodiments where the fluid is ethylene glycol, it may be advantageous to use ethylene glycol as the lubricant to facilitate insertion of the fin carrier 47 into the conduit 32. In yet another embodiment, the lubricant can be graphite powder.

[0059] It should be noted that the lubricant also inhibits the presence of small air gaps between some portions of the outer surface 68 of the insert 34 and the inner surface 38 of the conduit 32 by filling any regions where air gaps may be present. Thus, heat is transferred from the conduit 32 into the insert 34 and thus from the insert 34 into the fluid.

[0060] The fins 42 can have any suitable shape. For example, each fin 42 can have a wavy shape. This increases the total surface area of each fin 42 compared to fins that are flat and extend directly radially inward. The increased surface area of the fins 42 having a wavy shape allows the fins 42 to have increased heat transfer to the fluid compared to fins that are flat and extend directly radially inward.

[0061] The features described herein for providing increased heat transfer to the fluid are advantageous because they transfer a selected amount of heat to the fluid to heat the fluid while maintaining the heating element 46 at a lower temperature than it would otherwise have to be if these features were not present. This allows the amount of power consumed by the heating element 46 to be reduced, but also helps to heat the fluid while inhibiting overheating of the heating element.

[0062] The heating element 46 can be any suitable type of heating element. For example, the heating element 46 can be a thick film heating element. Alternatively, the heating element 46 can be a thin film heating element. Other types of heating elements 46 can be used. The heating element 46 can be mounted to engage the outer surface 40 of the conduit 32 (e.g., by bonding the heating element 46 to a thermally conductive layer on the outer surface of the conduit 32).

[0063] Referring Figure 6A The fluid heater 28 can also include a conduit housing 66 surrounding the conduit 32. The conduit housing 66 can be made of any suitable material, such as a material that is less thermally conductive than the material of the conduit 32, to help inhibit heat transfer from the fluid heater 28 to the surrounding environment. Examples of such materials for the conduit housing 66 include polymeric materials, such as a nylon.

[0064] The conduit housing 66 includes a plurality of conduit housing portions. In the illustrated example, the conduit housing 66 includes a first conduit housing portion 66a and a second conduit housing portion 66b. However, the conduit housing 66 can optionally also include additional conduit housing portions. The conduit housing 66 has a first end 72 and a second end 74.

[0065] The fluid heater 28 can also include an inlet member 76 sealingly engaged to the inlet end 78 of the conduit 32 and an outlet member 80 sealingly engaged to the outlet end 82 of the conduit 32. Both the inlet member 76 and the outlet member 80 can be made of a polymeric material that is less thermally conductive than the material of the conduit 32. For example, the inlet member 76 and the outlet member 80 can be made of a nylon.

[0066] The inlet member 76 and the outlet member 80 can each include a conduit protrusion 84 that extends longitudinally into the conduit 32 and sealingly mates with the conduit 32 (e.g., via at least one sealing member 86, such as Figure 4 the plurality of O-rings shown).

[0067] The inlet member 76 and the outlet member 80 can each also include a flange 87 that sealingly mates with the conduit housing 66. For example, the flange 86 of the inlet member 76 can sealingly engage the first end 72 of the conduit housing 66, and the flange 86 of the outlet member 80 can sealingly engage the second end 74 of the conduit housing 66.

[0068] The inlet member 76 and the outlet member 80 are joined to the conduit housing 66 by any suitable means, such as by welding (e.g., ultrasonic welding) or by a suitable adhesive, or even mechanically by threaded fasteners. Similarly, multiple conduit housing portions can be joined together by welding, by a suitable adhesive, or even by threaded fasteners.

[0069] In the illustrated embodiment, the inlet member 76 and the outlet member 80 themselves can be formed of multiple elements that can be joined together by any suitable means, such as by welding, by a suitable adhesive, or by threaded fasteners.

[0070] Referring Figure 3 and Figure 4 , the fluid heater 28 can also include a controller 88 and a controller housing 90. The controller 88 includes a processor 88a and a memory 88b connected to the processor 88a (e.g., since both the memory 88b and the processor 88a are mounted on a common printed circuit board (PCB) 88c). The memory 88b stores instructions executable by the processor 88a to control the operation of the heating element 36. The processor 88a can control the operation of the heating element 36 by any suitable means, such as by one or more IGBTs that can be mounted to the PCB 88c. The instructions for controlling the operation of the heating element 36 can be any suitable instructions and can incorporate any suitable control method. For example, the control method can include a PID control algorithm for operating the heating element 36 to reach a selected temperature. The heating element 36 can be turned on and off using pulse width modulation to execute the PID control algorithm. Alternatively, any other suitable control method can be used.

[0071] The controller housing 90 can optionally include a vent 92 that allows pressure equalization between the controller housing 90 and the surrounding environment in the event that the pressure in the controller housing 90 increases or decreases relative to the surrounding environment. For example, if the air in the controller housing 90 is heated, such as by heating one or more IGBTs, the pressure of the air in the controller housing 90 will increase. However, the vent 92 inhibits this by allowing air to leave the controller housing 90 as needed. The vent 92 can be covered by a membrane 94 that allows air to enter and leave the controller housing 90 as needed while inhibiting moisture from entering the controller housing 90. The membrane 94 can be made of a material such as a Gore-Tex TM material.

[0072] The controller housing 90 can be made of any suitable material such as a metal such as aluminum or stainless steel, or a polymeric material such as a nylon. The controller housing 90 can be made of one or more controller housing elements, such as a first controller housing element 90a and a second controller housing element 90b, which can be joined together by any suitable means, such as by glue.

[0073] Installation of the conduit housing to the controller housing

[0074] As Figure 3 shown, the conduit housing 66 can be installed to the controller housing 90. This installation can be carried out by any suitable means. For example, one of the conduit housing 66 and the controller housing 90 can include a position locking protrusion 96 that mates with a position locking orifice 98 ( Figure 4 ) on the other of the conduit housing 66 and the controller housing 90. The position locking protrusion 96 can have any suitable shape that mates with the position locking orifice 98 to fix the position of the conduit housing 66 on the controller housing 90. To this end, the position locking protrusion 96 can have any cross-sectional shape other than circular. In an example, the position locking protrusion 96 can have a generally trapezoidal cross-sectional shape. Alternatively, the position locking protrusion 96 can have the shape of another polygon, such as a square or a triangle. The polygon can be a regular polygon or an irregular polygon. Alternatively, the shape can be an ellipse, or any other regular or irregular shape. In the example shown, the conduit housing 66 includes the position locking protrusion 96, and the controller housing 90 includes the position locking orifice 98.

[0075] In the illustrated embodiment, there are a first position locking protrusion and a second position locking protrusion 96 shown separately as 96a and 96b. The first position locking protrusion 96a and the second position locking protrusion 96b can be used to more firmly position the first conduit housing portion 66a than a single position locking protrusion 96. The first position locking protrusion 96a includes a first portion 96a1 located on the first conduit housing portion 66a and a second portion 96a2 located on the second conduit housing portion 66b. Thus, the first position locking protrusion 96a additionally locks the position of the second conduit housing portion 66b relative to the first conduit housing portion 66a. The controller housing 90 correspondingly includes a first position locking orifice 98a shown as 98a and a second position locking orifice 98b shown as 98b for receiving the first position locking protrusion 96a and the second position locking protrusion 96b, respectively.

[0076] The controller housing 90 and the conduit housing 66 may also include fastener apertures, shown at 100 and 102 respectively, for receiving a threaded fastener 104 that is used to retain the conduit housing 66 on the controller housing 90. In the illustrated embodiment, the controller housing 90 includes two spaced-apart fastener apertures 100, and the conduit housing 66 also includes two spaced-apart fastener apertures 102 that are aligned with the fastener apertures 100. Any suitable number of fastener apertures 100 and 102 and threaded fasteners 104 may be used.

[0077] Although multiple position locking protrusions 96 and position locking apertures 98 are shown, alternatively, especially when other mounting mechanisms, such as fastener apertures 100 and 102 and associated fasteners 104, are also provided, only one position locking protrusion 96 may be provided instead of two position locking protrusions.

[0078] Through-hole between the conduit housing and the controller housing

[0079] The controller housing 90 includes a first controller housing air port 106 ( Figure 4 ), and the conduit housing 66 includes a first conduit housing air port 108 ( Figure 7 ), which is sealingly coupled to the first controller housing air port 106 to form a first through-hole between the controller housing 90 and the conduit housing 66, thereby allowing pressure equalization between the conduit housing 66 and the controller housing 90.

[0080] By providing a vent 92 on the controller housing 90 and by providing a first through-hole between the controller housing 90 and the conduit housing 66, the pressures in the conduit housing 66 and the controller housing 90 can both be maintained at approximately atmospheric pressure.

[0081] The first controller housing air port 106 and the first conduit housing air port 108 may be coupled using glue or any other suitable means.

[0082] The first through-hole may also be used to electrically connect the controller 88 to the heating element 36. As Figure 4 and Figure 7 shown, a bus bar 112 is shown, which includes a first set of bus bar terminals 114 and a second set of bus bar terminals 116. The first set of bus bar terminals 114 (which includes a positive terminal and a negative terminal) connects the bus bar 112 to the controller 88. The second set of bus bar terminals 116 (which also includes a positive terminal and a negative terminal) connects the bus bar 112 to the heating element 36, thereby electrically connecting the heating element 36 to the controller 88. Thus, the controller 88 can drive the operation of the heating element 36.

[0083] Optionally, a second controller housing air port 118 and a second conduit housing air port 120 may be provided on the controller housing 90 and the conduit housing 66, respectively. The second controller housing air port 118 and the second conduit housing air port 120 are sealingly mated together (e.g., by glue or by any other suitable means) to form a second through-orifice between the controller housing 90 and the conduit housing 66. The second through-orifice may allow the electrical conduit 124 ( Figure 7 ) to extend between the controller 88 and the temperature sensor 126, which is positioned to sense a temperature related to the temperature of the fluid and send a signal indicative of the temperature of the fluid to the controller 88. The temperature sensor 126 may be positioned directly inside the conduit 32 to directly sense the temperature of the fluid. Alternatively, the temperature sensor 126 may be positioned directly on the outer surface 40 of the conduit 32, as Figure 7 shown, and the controller 88 may be programmed to apply a selected conversion formula to determine the temperature of the fluid based on the temperature sensed by the temperature sensor 126 (i.e., based on the temperature of the conduit 32). Alternatively, the temperature sensor 126 may be positioned in contact with some other component of the fluid heater 28, where a different conversion formula may be used to determine the temperature of the fluid based on the temperature sensed by the temperature sensor 126.

[0084] Circumferential gap in the insert

[0085] Referring to Figure 8 , Figure 8 an optional circumferential gap 128 is shown extending longitudinally along the entire outer surface 68 of the insert 34. The circumferential gap 128 allows the fin carrier 47 to be radially compressed away from the neutral position. The neutral position is shown by a dotted line denoted 130 in Figure 9 . The fin carrier 47 is shown by a dashed line denoted 132 in Figure 9 to be in a radially compressed position, where the side edges of the circumferential gap 128 are closer to each other than when in the neutral position, and the side edges may even be as Figure 9abut against each other as shown in. By compressing the fin carrier 47 into a radially compressed state, the fin carrier 47 can be easily inserted into the conduit 32. Once inserted into the conduit 32, the fin carrier 47 can be released from the radial compression to allow it to subsequently expand radially towards the neutral position 130. However, the conduit 32 can be sized to have a selected amount of interference with the fin carrier 47, and thus, the conduit 32 can be sized to prevent the fin carrier 47 from returning to the neutral position 130 when the fin carrier 47 is released from the radial compression while the fin carrier 47 is inside the conduit 32. Shown at 134 is the fin carrier 47 in the use position engaged with the inner surface 38 of the conduit 32 when released inside the conduit 32. It should be noted that, for simplicity, Figure 9 the fins 42 are not shown. Only the peripheral member 46 is shown.

[0086] Referring to Figure 10 , Figure 10 an alternative configuration for the circumferential gap is shown at 136. The circumferential gap 136 extends helically along the insert 34, but can still be said to extend longitudinally along the entire outer surface 68 of the insert 34, even though the circumferential gap does not extend directly longitudinally.

[0087] In Figure 10 the configuration shown, although the fins are not shown, it should be noted that the gap 136 can extend radially downward through a portion of the radial length of the fins 42 to allow portions of the fins 42 to move relative to each other as needed to accommodate radial compression of the insert 34. Although the gap 128 has been shown as extending through the entire radial thickness of the peripheral member 46, it should be noted that in some embodiments, the gap 128 can extend only partially through the radial thickness of the peripheral member 46 while still allowing sufficient radial compression of the fin carrier 47 prior to insertion of the fin carrier 47 into the conduit 32.

[0088] Instead of providing such as Figure 8 and Figure 10For the circumferential gap shown in the figure, any other suitable way of inserting the fin carrier 47 into the conduit 32 can be used. For example, the fin carrier 47 can be cooled to a first suitable temperature to cause it to thermally contract, while the conduit 32 can be heated to a second suitable temperature to cause it to thermally expand, such that the relative dimensions of the fin carrier 47 and the conduit 32 allow the fin carrier 47 to be inserted into the conduit 32 more easily than when the fin carrier and the conduit are at the same temperature. After the fin carrier 47 is inserted into the conduit 32, the fin carrier 47 and the conduit 32 can be brought to the same temperature (e.g., the temperature in the assembly plan for manufacturing the fluid heater 28), and the fin carrier 47 and the conduit 32 will be joined together by an interference fit, thereby providing good thermal contact between them.

[0089] Once the fin carrier 47 is inserted into the conduit 32, the core member 44 can be inserted into the fin carrier 47 as described above, and the core locking member 60 can be installed onto the core member 44 to lock it to the fins 42 of the fin carrier 47.

[0090] Generally, it is advantageous for the temperature of the heating element 36 not to exceed a selected temperature in order to ensure that the heating element 36 is not damaged. Additionally, it is advantageous for the pressure drop across the conduit 32 to be below a selected threshold in order to ensure that not too much energy is wasted in driving the fluid flow through the conduit 32. Based on simulations, it has been found that the illustrated embodiment of the insert 34 will have a pressure drop of approximately 28 mbar, and the heating element 36 will have a maximum temperature of 271 degrees Celsius.

[0091] Therefore, an embodiment of the insert 34 is provided that achieves a favorable combination of a relatively low maximum temperature in the heating element 36 and a relatively low pressure drop across the conduit 32.

[0092] Referring to Figure 19 and Figure 20 , Figure 19 and Figure 20 show another embodiment of the insert 34. In the embodiment shown in Figure 19 , the fin carrier 47 is shown as having an outer peripheral member 46 and fins 42. A circumferential gap 128 is shown in these figures. It should be noted that the circumferential gap 128 extends radially all the way through the fin carrier 47 in the embodiments shown in Figure 19 and Figure 20 (and in the embodiment shown in Figure 8 , even though the fins 42 are not shown in this figure). In Figure 19 and Figure 20In the embodiment shown, the insert 34 includes a core member 44. However, in this embodiment, the core member 44 is an expansion member shown at 182. The expansion member 182 itself has a circumferential gap shown at 184. The circumferential gap 184 of the expansion member 182 is aligned with the circumferential gap 128 of the fin carrier 47. In this sense, the circumferential gap 184 of the expansion member 182 is located between the first fin 42a and the second fin 42b, and the circumferential gap 128 of the fin carrier 47 is also located between the first fin 42a and the second fin 42b.

[0093] The circumferential gap 184 allows the expansion member 182 to be elastically radially compressed away from the neutral position (represented by the dashed circle shown at 186 in Figure 9 ) in a manner similar to the elastic radial compression of the fin carrier 47 shown in Figure 20 . The dashed circle represents the perimeter of the outer surface of the expansion member 182 in the neutral position of the expansion member 182. To install the expansion member 182 in the fin carrier 47, the fin carrier 47 itself can first be installed in the conduit 32. The expansion member 182 can be elastically radially compressed by shrinking the circumferential gap 184, and then can be inserted into the space between the inner ends 48 of the fins 42. Once the expansion member 182 has been inserted, it can be allowed to radially expand towards the neutral position of the expansion member 182 under its own restoring force. The inner ends 48 of the fins 42 are positioned to prevent the expansion member 182 from returning to the neutral position of the expansion member 182 when the expansion member 182 is released from the elastic radial compression of the expansion member 182, so that the expansion member 182 urges the fin carrier 47 to expand by applying a radially outward force (i.e., an expansion force) against the fins 42. This radially outward force drives the fin carrier 47 into stronger contact with the inner surface 38 of the conduit 32 to further reduce any air gap in the radial direction between the fin carrier 47 and the conduit 32, in order to improve heat transfer between the conduit 32 and the fin carrier 47.

[0094] In the embodiment shown, the expansion member 182 is hollow, and thus at least some fluid flow passes through the expansion member. Nevertheless, the expansion member 182 occupies at least a portion of the radially inward cross-sectional area of the plurality of fins 42, so as to drive a portion of the fluid to flow around the expansion member 182 and engage the plurality of fins 42. In the embodiment shown, the expansion member 182 drives a portion of the fluid (i.e., the first portion of the fluid) to flow around the expansion member 182 and engage the plurality of fins 42, and drives a second portion of the fluid to flow inside the expansion member 182.

[0095] The expansion member 182 can be made of any suitable material such as metal, for example stainless steel or aluminum.

[0096] Alternative configurations for fins

[0097] Although the insert 34 has been shown to include both a fin carrier 47 and a core member 44, it should be noted that in some embodiments, an insert including only the fin carrier 47 may be provided such that there is no obstruction to fluid flow radially internal to the fins 42. This embodiment has a lower pressure drop; however, because fluid flow is permitted in the region of the conduit that is radially internal to the fins 42, the heating element 36 needs to reach a higher temperature in order to achieve a selected temperature for the fluid. Based on simulation, the pressure drop across the conduit 32 is 17 mbar and the maximum temperature of the heating element 36 is 312 degrees Celsius.

[0098] Reference Figure 11 and Figure 12 , Figure 11 and Figure 12 show alternative embodiments for the insert 34. In the embodiments shown in Figure 11 and Figure 12 , the insert includes a plurality of fins 42 in the form of helical vanes 140 that are connected to and spiral around a core member 44. The helical vanes 140 optionally extend radially from the core member 44 to the inner surface 38 of the conduit 32 in order to engage the inner surface 38 of the conduit 32. Based on simulation, the pressure drop across the conduit 32 is 36 mbar and the maximum temperature of the heating element 36 is 245 degrees Celsius. In an alternative embodiment similar to the embodiments shown in Figure 11 and Figure 12 , there may be only a single helical vane 140 rather than a plurality of helical vanes 140. Thus, it can be said that the insert 34 includes at least one fin 42, the at least one fin 42 including at least one helical vane 140 that is connected to and spiral around a core member 44. In the embodiments shown in Figure 11 and Figure 12 and in the alternative embodiments described above, it should be noted that, as in the embodiment shown in Figure 4 , the core member 44 may be polymeric and, similar to the fins 42 shown in Figure 4 , the at least one helical vane 140 may be polymeric or may be made of a material with good thermal conductivity such as metal in order to transfer heat from the conduit 32 along the at least one helical vane 140 to the fluid.

[0099] Specifically as can be seen in Figure 11 , the helical vanes 140 may be relatively thin. In order to hold the insert 34 securely within the conduit 32, a plurality of support arms 180 may extend outward to engage the inner surface 38 of the conduit 32. As in Figure 12As can be seen, the support arm 180 is strong enough to engage the inner surface 38 firmly and hold the insert 34 in place during operation of the fluid heater 28 while fluid flows through the conduit 32. For example, the support arm 180 can be sized to interference fit with the inner surface 38 of the conduit 32 to engage the inner surface 38 firmly and be strong enough to avoid buckling. As shown in Figure 11 As can be seen, the support arm 180 can be disposed at a plurality of axial positions along the core member 44, such as at the first end 54 and the second end 58 of the core member 44.

[0100] It should be noted that in the above alternative embodiments and in the embodiments shown and described with respect to Figure 11 and Figure 12 it can be said that the core member 44 occupies at least a portion of the radially inward cross-sectional area of at least one helical fin 140 so as to drive a portion of the fluid to flow around the core member 44 and engage at least one helical fin 140.

[0101] Referring to Figure 13 and Figure 14 and Figure 13 and Figure 14 illustrate embodiments of the insert 34 in which the insert 34 includes a plurality of fins 42 in the form of helical fins 142 that are connected to the core member 44 and extend helically around the core member 44, and the plurality of fins 42 extend radially from the core member 44 towards the inner surface 38 of the conduit 32 such that the plurality of helical fins 142 are spaced apart from the inner surface 38 of the conduit 32 by a radial gap 141. In an alternative embodiment similar to the embodiments shown in Figure 13 and Figure 14 there may be only a single helical fin 142 instead of a plurality of helical fins 142. Based on simulations of such an embodiment, the pressure drop across the conduit 32 is 40 mbar and the maximum temperature of the heating element 36 is 293 degrees Celsius. Thus, it can be said that the insert 34 includes at least one fin 42 that includes at least one helical fin 142 that is connected to the core member 44 and extends helically around the core member 44. It should be noted that in the embodiments shown and described with respect to Figure 13 and Figure 14 it can be said that the core member 44 occupies at least a portion of the radially inward cross-sectional area of at least one helical fin 142 so as to drive a portion of the fluid to flow around the core member 44 and engage at least one helical fin 142.

[0102] Based on the above with respect to Figures 11 to 14Description of the associated alternative embodiments, it can be said that the fluid heater 28 includes: a conduit (such as conduit 32) for conveying a fluid stream and having an inner surface and an outer surface (such as inner surface 38 and outer surface 40); an insert (such as Figures 11 to 14 the insert 34 shown in Figures 11 to 14 or otherwise described and provided with at least one fin 42), which is positioned inside the conduit and includes a core member (such as Figures 11 to 14 the core member 44 shown in Figures 11 to 14 ) and at least one fin, the at least one fin extending radially and including at least one helical fin (such as one or more helical fins 140 or one or more helical fins 142) connected to and helically extending around the core member. The core member occupies at least a part of the radially inward cross-sectional area of at least one helical fin so as to drive a part of the fluid to flow around the core member and engage at least one helical fin. The fluid heater 28 further includes a heating element (such as any embodiment of the heating element 36 described herein), which is energizable to heat the fluid.

[0103] In Figure 13 and Figure 14 In the embodiments shown in Figure 13 and Figure 14 , it should be noted that the core member 44 can be polymeric, as in the embodiments shown in Figure 4 Figure 4 , and at least one helical fin 140 can be polymeric or made of metal or any other suitable material or combination of suitable materials, since at least one helical fin 142 is spaced apart from the inner surface of the conduit 32.

[0104] As described above, the helical fin 142 does not engage the inner surface 38 of the conduit 32. To firmly hold the insert 34 in the conduit 32, a plurality of support arms 180 can extend outwardly to engage the inner surface 38 of the conduit 32. As can be seen in Figure 13 Figure 13 , the support arms 180 are strong enough to firmly engage the inner surface 38 and hold the insert 34 in place during the operation of the fluid heater 28 while the fluid flows through the conduit 32. For example, the support arms 180 can be sized to interference fit with the inner surface 38 of the conduit 32 so as to firmly engage the inner surface 38 and be strong enough to avoid buckling. As can be seen in Figure 14 Figure 14 , the support arms 180 can be provided at a plurality of axial positions along the core member 44, such as at the first end 54 and the second end 58 of the core member 44.

[0105] Increased fluid flow outside the curve

[0106] Referring to Figure 15 , Figure 15 shows a computer-generated image that illustrates based on Figures 5A to 5CThe fluid flow in conduit 32 of fin 42 as shown. The fluid is represented by the section shown at 143. The negative space in the image is the space occupied by fin 42 itself and the space occupied by core member 44. To the right of the image of the section with fluid 143 is a graph showing the flow velocity associated with the selected shading. As can be seen, the area of fluid 143 with the highest flow velocity is shown at 143a and is all on the left side of the image. It can also be seen that the overall flow in the section of fluid 143 on the left side of the image is higher than the overall flow in the section of fluid 143 on the right side of the image. This is because, in Figures 3 to 7 the embodiment shown, based on the orientation of inlet member 76 and outlet member 80, centrifugal force pushes the fluid towards the "outer side of the curve". More clearly and with reference to Figure 16 , Figure 16 shows a cross-sectional view of conduit 32 and inlet member 76 and outlet member 80. Conduit 32 has a longitudinal plane P. The inlet end (shown at 145) of inlet member 76 and the outlet end (shown at 147) of outlet member 80 are both on the first side 144 of longitudinal plane P such that, due to centrifugal force, a greater proportion of the fluid flow through fluid heater 28 travels on the second side 146 of the longitudinal plane than travels on the first side of the longitudinal plane. To more uniformly heat the fluid in conduit 32 and thus avoid overheating of certain parts of heating element 36 which could damage heating element 36, heating element 36 is positioned to generate a greater amount of heat on the second side 146 of longitudinal plane P than on the first side 144 of longitudinal plane P. In Figure 4 and Figure 6A the embodiment shown, heating element 36 can be positioned such that the entire circular cross-section of conduit 32 on the second side 146 of longitudinal plane P is heated by heating element 36, while only a portion of the circular cross-section of conduit 32 on the first side 144 of longitudinal plane P is heated by heating element 36. More specifically, it can be seen that there is an unheated circumferential region 148 on the first side 144 of longitudinal plane P of conduit 32.

[0107] Induction heating element

[0108] With reference to Figure 17 . Heating element 36 can be something other than a resistance-based heating element. For example, Figure 17The heating element 36 therein is shown as an induction heating element 150. Thus, the induction heating element 150 includes an induction coil 152 which may have any suitable form. For example, the induction coil 152 may be in the form of a Litz wire. Alternatively, the induction coil may be in the form of a hollow tube. The induction heating element 150 may inductively heat the fluid in any suitable manner. For example, the induction heating element 150 may inductively heat the conduit 32, which in turn may conduct heat into the fin carrier 47 in the case where the fin carrier 47 is made of a material not inductively heated by the induction heating element 150 itself. Alternatively, the induction heating element 150 may inductively heat the conduit 32 and the fin carrier 47. It should be noted that even if both the conduit 32 and the fin carrier 47 are heated by the induction heating element 150, the conduit 32 may still conduct heat into the fin carrier 47. Alternatively, the induction heating element 150 may heat the fin carrier 47 more than it heats the conduit 32, or may heat only the fin carrier 47 and not the conduit 32. Those skilled in the art will understand that which of the fin carrier 47 and the conduit 32 is heated by the induction heating element 150 depends on factors such as the frequency of the EMF emitted by the induction heating element 150 and the construction materials of the fin carrier 47 and the conduit 32. Thus, these factors can be selected to achieve any desired configuration.

[0109] Although the induction coil 152 is shown as helically wound around the entire circumference of the conduit 32, alternatively, the induction coil 152 may also be arranged in a planar arrangement in a slightly helical manner, which can be applied to the outer surface 40 of the conduit 32.

[0110] In Figure 17In the embodiment shown, there is an optional amount of internal insulator 154 located radially between catheter 32 and induction heating element 150. The amount of internal insulator 154 can be any suitable type of insulator and is made of a material that inhibits heat transfer and is "transparent" to the EMF transmitted by induction heating element 150. Additionally or alternatively, there can be an amount of external insulator (not shown) located radially between induction heating element 10 and catheter housing 66. The amount of external insulator can be any suitable type of insulator and is made of a material that inhibits heat transfer and can be or can not be "transparent" to the EMF transmitted by induction heating element 150. There can be an EMF shield 158 also radially positioned between induction heating element 10 and catheter housing 66. EMF shield 158 can be made of a material selected to absorb the EMF forces emitted by induction heating element 150 so as to inhibit the emission of EMF forces radially beyond EMF shield 158. EMF shield 158 can be a separate element mounted in catheter housing 66. Alternatively, EMF shield 158 can be a layer or coating applied to the interior of catheter housing 66. Alternatively, EMF shield 158 can be formed in any other suitable manner and can be positioned at any other location suitable for shielding EMF forces from induction heating element 150.

[0111] U-shaped configuration for increasing heat transfer

[0112] For some applications, it may be beneficial to provide the fluid with a relatively greater amount of heat than that provided by heating element 36. For such applications, the configuration of catheter 32 can be as shown in Figure 18 In this embodiment, catheter 32 is U-shaped and includes a straight inlet catheter portion 160, a direction-changing catheter portion 162, and a straight outlet catheter portion 164. Insert 34 is a first insert (shown as 34a) and is positioned in inlet catheter portion 160, and heating element 36 is a first heating element (shown as 36a) and is positioned adjacent to the outer surface 40 of catheter 32 at inlet catheter portion 160. Catheter 32 also includes a second insert 34 (specifically shown as 34b) positioned inside outlet catheter portion 164. Second insert 34b can be similar to first insert 34a and thus can include a plurality of second fins 42 and a second core member 44, the plurality of second fins 42 extending radially inwardly relative to catheter 32 at second catheter portion 164, and second core member 44 occupying at least a portion of the radially inward cross-sectional area of the plurality of second fins 42 so as to drive a portion of the fluid to flow around second core member 44 and engage the plurality of second fins 42.

[0113] In some embodiments, inlet catheter portion 162 and outlet catheter portion 164 can be similar in construction toFigure 4 The conduit 32 shown in , and can thus be metallic. The direction-changing conduit portion 162 can be polymeric and can be sealingly engaged with the inlet conduit portion 162 and the outlet conduit portion 164 using a structure similar to that shown for the inlet member 76 and the outlet member 80 (e.g., by insertion into the inlet conduit portion 162 and the outlet conduit portion 164 and using a sealing member 86).

[0114] Additional articles

[0115] Reference Figure 3 , the fluid heater 28 can also include a high-voltage connector 170 for connecting a high-voltage power source to transmit power from the high-voltage source (e.g., the battery pack 12) to the controller 88 for ultimately powering the heating element 36. The fluid heater 28 can also include a low-voltage connector 172 for connecting a low-voltage power source to transmit power from the low-voltage source (e.g., a low-voltage (e.g., 12V) battery (not shown) on the vehicle 10) to the controller 88 for powering the controller 88 itself.

[0116] Description of other alternatives

[0117] Although Figure 1 the vehicle 10 shown in is an electric vehicle, it should be understood that the vehicle 10 can alternatively be a vehicle that uses an internal combustion engine and does not use an electric motor to drive the wheels 15. In such a case, the fluid heater 28 can be used to heat the fluid used in the vehicle's power steering system or any other suitable fluid for any other suitable purpose.

[0118] Throughout this disclosure, it has been stated that the core member occupies at least a portion of the radially inward cross-sectional area of at least one helical fin in order to drive a portion of the fluid to flow around the core member and engage at least one helical fin or a plurality of fins. To make the meaning of the foregoing text clearer, the phrase "a portion of the fluid" is used herein rather than "the fluid" or "the entire fluid" because some portions of the fluid (e.g., the portions of the fluid that are in direct contact with the conduit 32 or the peripheral member 46) have flowed around the core member and engaged the plurality of fins 42 rather than being driven to do so by the core member 44.

[0119] The fluid heater 28 also includes a heating element (e.g., any embodiment of the heating element 36 described herein) that can be energized to heat the fluid.

[0120] Although the descriptions contained herein constitute various embodiments of the present invention, it will be understood that further modifications and changes can be made to the present invention without departing from the fair meaning of the appended claims.

[0121] List of articles and reference numerals

[0122]

[0123]

[0124]

[0125]

[0126]

Claims

1. A fluid heater, comprising: a conduit for conveying a fluid stream, having an inner surface and an outer surface; and an insert positioned inside the conduit and including a plurality of fins and a core member, the plurality of fins extending radially inwardly relative to the conduit, the core member occupying at least a portion of the radially inward cross-sectional area of the plurality of fins so as to drive a portion of the fluid to flow around the core member and engage the plurality of fins; and a heating element that is energizable to heat the fluid.

2. The fluid heater according to claim 1, wherein, The insert includes a peripheral member positioned to engage the inner surface of the conduit, and wherein the plurality of fins are connected to the peripheral member to form a fin carrier and extend radially inwardly from the peripheral member, wherein each fin has a radially inner end, and wherein the core member is separate from and engages the plurality of fins so as to stabilize the radially inner ends of the plurality of fins.

3. The fluid heater according to claim 1, further comprising: an inlet member sealingly engaged to an inlet end of the conduit; an outlet member sealingly engaged to an outlet end of the conduit; and wherein the conduit is metallic and the inlet member and the outlet member are made of a polymeric material.

4. The fluid heater according to claim 3, further comprising a conduit housing made of a polymeric material and surrounding the conduit, and the conduit housing is connected to the inlet member and the outlet member.

5. The fluid heater according to claim 4, wherein, The inlet member and the outlet member each include a conduit projection longitudinally extending into the conduit and sealingly mating with the conduit, and wherein the inlet member and the outlet member each include a flange sealingly mating with the conduit housing.

6. The fluid heater according to claim 5, wherein, The flange is welded to the conduit housing.

7. The fluid heater according to claim 4, further comprising: a controller housing; and a controller including a processor and a memory connected to the processor, wherein the memory stores instructions executable by the processor to control the operation of the heating element, and wherein the controller is positioned inside the controller housing.

8. The fluid heater according to claim 7, wherein, The controller housing includes a vent to allow fluid communication between the controller housing and the surrounding environment around the fluid heater, and wherein the controller housing includes a controller housing air port and the conduit housing includes a conduit housing air port, the conduit housing air port being sealingly connected to the controller housing air port to allow pressure equalization between the conduit housing and the controller housing.

9. The fluid heater according to claim 1, wherein, The heating element is a thick film heater.

10. The fluid heater according to claim 1, wherein, The heating element is an induction heating element.

11. The fluid heater according to claim 10, further comprising a quantity of internal insulator radially located between the conduit and the induction heating element.

12. The fluid heater according to claim 10, further comprising a quantity of external insulator radially located between the induction heating element and the conduit housing.

13. The fluid heater according to claim 3, wherein, The catheter has a longitudinal plane, and wherein, the inlet member has an inlet end, and the outlet member has an outlet end, and wherein, both the inlet end and the outlet end are on a first side of the longitudinal plane, such that a greater proportion of the fluid flow through the fluid heater travels on a second side of the longitudinal plane than travels on the first side of the longitudinal plane, and wherein, the heating element is positioned to generate a greater amount of heat on the second side of the longitudinal plane than on the first side of the longitudinal plane.

14. The fluid heater according to claim 2, wherein, The fin carrier has an outer surface and has an outer peripheral edge, and has a circumferential gap extending longitudinally along the entire outer surface of the fin carrier, wherein, the circumferential gap allows the insert to be elastically radially compressed away from a neutral position for inserting the fin carrier into the catheter, and then radially expand towards the neutral position when the fin carrier is released from the elastic radial compression, wherein, the catheter is sized to prevent the fin carrier from returning to the neutral position when the fin carrier is released from the elastic radial compression while the fin carrier is inside the catheter.

15. The fluid heater according to claim 2, wherein, The core member includes a plurality of longitudinal grooves for receiving the radially inner ends of the plurality of fins.

16. The fluid heater according to claim 15, wherein, Each longitudinal groove has a blind end at a first end of the core member and an open end at a second end of the core member, and wherein, the fluid heater further includes a core locking member that mechanically engages the second end of the core member to prevent the core member from being removed from the fin carrier.

17. The fluid heater according to claim 1, wherein, The catheter is U-shaped and includes a straight inlet catheter portion, a direction-changing catheter portion, and a straight outlet catheter portion, wherein, the insert is a first insert and is positioned in the inlet catheter portion, and the heating element is a first heating element and is positioned adjacent to the outer surface of the catheter at the inlet catheter portion, and wherein, the catheter further includes a second insert positioned inside the outlet catheter portion, wherein, the second insert includes a plurality of second fins and a second core member, the plurality of second fins extend radially inward relative to the catheter at the second catheter portion, and the second core member occupies at least a part of the radially inward cross-sectional area of the plurality of second fins so as to drive the portion of the fluid to flow around the second core member and engage the plurality of second fins.

18. The fluid heater according to claim 17, wherein, The direction-changing catheter portion is polymeric, and wherein, the inlet catheter portion and the outlet catheter portion are metallic.

19. The fluid heater according to claim 2, wherein, The core member is polymeric, and the plurality of fins and the outer peripheral edge member are metallic.

20. The fluid heater according to claim 1, wherein, The plurality of fins are a plurality of helical fins connected to the core member and spirally extending around the core member.

21. The fluid heater according to claim 20, wherein, The plurality of helical fins radially extend from the core member to the inner surface of the catheter so as to engage the inner surface of the catheter.

22. The fluid heater according to claim 20, wherein, The plurality of helical fins extend radially from the core member towards the inner surface of the conduit such that the plurality of helical fins are spaced apart from the inner surface of the conduit.

23. The fluid heater according to claim 22, wherein Each of the plurality of fins has a wavy shape.

24. The fluid heater according to claim 14, wherein, The plurality of fins include a first fin and a second fin, and wherein the circumferential gap extends longitudinally between the first fin and the second fin, and wherein the core member is an expandable member having a circumferential gap that extends longitudinally between the first fin and the second fin and that permits the expandable member to be elastically radially compressed away from a neutral position of the expandable member for insertion of the expandable member into the space between the inner ends of the plurality of fins and then to radially expand towards the neutral position of the expandable member when the fin carrier is released from the elastic radial compression of the expandable member, wherein the inner ends of the fins are positioned to prevent the expandable member from returning to the neutral position of the expandable member when the expandable member is released from the elastic radial compression of the expandable member, such that the expandable member urges the fin carrier to expand by applying a radially outward force against the plurality of fins.

25. The fluid heater according to claim 24, wherein, The expandable member is hollow and thereby drives a first portion of the fluid to flow around the expandable member and engage the plurality of fins and also drives a second portion of the fluid to flow inside the expandable member.

26. A fluid heater comprising: a conduit for conveying a fluid stream and having an inner surface and an outer surface; an insert positioned inside the conduit and comprising: a core member; at least one fin that extends radially, wherein the at least one fin is at least one helical fin connected to and helically extending around the core member, wherein the core member occupies at least a portion of the radially inward cross-sectional area of the at least one helical fin so as to drive a portion of the fluid to flow around the core member and engage the at least one helical fin; and a heating element that is energizable to heat the fluid.

27. The fluid heater according to claim 26, wherein, The at least one helical fin extends radially from the core member to the inner surface of the conduit so as to engage the inner surface of the conduit.

28. The fluid heater according to claim 26, wherein, The at least one helical fin extends radially from the core member towards the inner surface of the conduit such that the at least one helical fin is spaced apart from the inner surface of the conduit.

Images