[0001] The present disclosure generally relates to heat transfer and, particularly, relates to heat transfer enhancement in tubes of heat exchangers.

BACKGROUND ART

[0002] Recent technological advances and increasing demands for high-performance heat exchangers have motivated researchers to study and develop innovative approaches to augment heat transfer characteristics. Heat transfer enhancement may refer to application of basic concepts of heat transfer processes to improve the rate of heat removal or deposition on a surface. In the flow of a fluid through a tube of a heat exchanger, the boundary layer theorem establishes that a laminar sub-layer exists where the fluid velocity is minimal. Heat transfer through this stagnant layer is partially removed or eliminated. Heat transfer enhancement methods may be classified into two main categories which are passive methods and active methods.

[0003] In the passive methods, no external energy may be used to increase the heat transfer coefficient. In the passive methods, various techniques may be used to break the thermal boundary layer. The use of expanded surfaces, inserting baffles, or application of soluble nanoparticles to change the base liquid’s thermodynamic properties are among the different passive methods for heat transfer enhancement. One of the main drawbacks of the passive methods may be their high-pressure drop which may decrement their performance.

[0004] The active methods for heat transfer enhancement may use an external energy source to enhance the heat transfer rate. Generally, these methods may be categorized as mechanical aids, fluid vibrating systems (ultrasound), magnetic field excitation for Fe-based nanofluids (magnetic hydrodynamic (MHD)), and electric current field excitation (electrohydrodynamic (EHD)) for the dielectric working fluids. Ultrasonic waves have not been famous due to their uneconomical efficiency and the local effect of this method on heat transfer, despite numerous studies. The MHD method may use iron-based nanofluids with low stability which may result in nanoparticles deposition and damage to equipment, making it inapplicable in industry.

[0005] The EHD method has also a limited range of industrial applications due to the use of dielectric working fluid, while the working fluid in the industry is mainly water. The use of surface vibration for heat transfer interface tubes and creating stress in the tubes does not effectively enhance heat transfer. Moreover, the energy consumed to vibrate the surface of the tubes is more than the increase in amount of associated heat transfer. There is, therefore, a need for a system that is able to increase heat transfer in tubes of heat exchangers with a positive energy balance.

SUMMARY OF THE DISCLOSURE

[0006] This summary is intended to provide an overview of the subject matter of the present disclosure, and is not intended to identify essential elements or key elements of the subject matter, nor is it intended to be used to determine the scope of the claimed implementations. The proper scope of the present disclosure may be ascertained from the claims set forth below in view of the detailed description below and the drawings.

[0007] In one general aspect, the present disclosure describes a system for increasing heat transfer and decreasing sedimentation in a tube of a heat exchanger. In an exemplary embodiment, the tube of the heat exchanger may contain a fluid. In an exemplary embodiment, the system may include a vibrating elastic wire, a permanent magnet, and an AC power supply.

[0008] In an exemplary embodiment, the vibrating elastic wire may be configured to be disposed inside a tube of a heat exchanger. In an exemplary embodiment, the permanent magnet may be attached to the vibrating elastic wire. In an exemplary embodiment, the electromagnet may be configured to be mounted on an outer surface of the tube of the heat exchanger.

[0009] In an exemplary embodiment, the AC power supply may be connected to the electromagnet. In an exemplary embodiment, the AC power supply may be configured to provide a variable electric current for the electromagnet. In an exemplary embodiment, the electromagnet may be configured to create a variable magnetic field inside the tube of the heat exchanger responsive to receiving the variable electric current from the AC power supply.

[0010] In an exemplary embodiment, the permanent magnet may be configured to vibrate inside the tube of the heat exchanger responsive to the permanent magnet being exposed to the variable magnetic field. In an exemplary embodiment, the vibrating elastic wire may be configured to increase heat transfer and decrease sedimentation inside the tube of the heat exchanger due to vibration of the vibrating elastic wire inside the tube of the heat exchanger responsive to vibrating the permanent magnet inside the tube of the heat exchanger.

[0011] In an exemplary embodiment, the electromagnet may be configured to be mounted on a middle point of the tube of the heat exchanger. In an exemplary embodiment, the permanent magnet may be attached to a middle point of the vibrating elastic wire. In an exemplary embodiment, the AC power supply may be configured to provide a variable electric current with a predefined frequency for the electromagnet. In an exemplary embodiment, the predefined frequency may be equal to a resonance frequency of the vibrating elastic wire.

[0012] In an exemplary embodiment, the vibrating elastic wire may be configured to be disposed inside the tube of the heat exchanger and along a first axis. In an exemplary embodiment, the first axis may coincide a main longitudinal axis of the tube. In an exemplary embodiment, the permanent magnet may be configured to vibrate inside the tube of the heat exchanger and along a second axis responsive to the permanent magnet being exposed to the variable magnetic field. In an exemplary embodiment, the second axis may be perpendicular to the first axis.

[0013] In an exemplary embodiment, the system may further include a first clamp. In an exemplary embodiment, the first clamp may be configured to attach a first end of the vibrating elastic wire to a first end of the tube. In an exemplary embodiment, the first clamp may include a first hollow cylinder and a first rod.

[0014] In an exemplary embodiment, the first hollow cylinder may be configured to be fitted inside the tube. In an exemplary embodiment, the first rod may be attached to an inner surface of the first hollow cylinder. In an exemplary embodiment, the first end of the vibrating elastic wire may be configured to be wrapped around the first rod.

[0015] In an exemplary embodiment, the system may further include a second clamp. In an exemplary embodiment, the second clamp may be configured to attach a second end of the vibrating elastic wire to a second end of the tube. In an exemplary embodiment, the second clamp may include a second hollow cylinder and a second rod.

[0016] In an exemplary embodiment, the second hollow cylinder may be configured to be fitted inside the tube. In an exemplary embodiment, the second rod may be attached to an inner surface of the second hollow cylinder. In an exemplary embodiment, the second end of the vibrating elastic wire may be configured to be wrapped around the second rod.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawing figures depict one or more implementations in accord with the present teachings, by way of example only, not by way of limitation. In the figures, like reference numerals refer to the same or similar elements.

[0018] FIG. 1A illustrates a perspective view of a system for increasing heat transfer and decreasing sedimentation in a tube of a heat exchanger, consistent with one or more exemplary embodiments of the present disclosure.

[0019] FIG. IB illustrates a side view of a system for increasing heat transfer and decreasing sedimentation in a tube of a heat exchanger, consistent with one or more exemplary embodiments of the present disclosure.

[0020] FIG. 2A illustrates a perspective view of a first clamp, consistent with one or more exemplary embodiments of the present disclosure.

[0021] FIG. 2B illustrates a side view of a first clamp, consistent with one or more exemplary embodiments of the present disclosure.

[0022] FIG. 2C illustrates a perspective view of a second clamp, consistent with one or more exemplary embodiments of the present disclosure.

[0023] FIG. 2D illustrates a side view of a second clamp, consistent with one or more exemplary embodiments of the present disclosure. DESCRIPTION OF EMBODIMENTS

[0024] In the following detailed description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant teachings. However, it should be apparent that the present teachings may be practiced without such details. In other instances, well known methods, procedures, components, and/or circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings.

[0025] The following detailed description is presented to enable a person skilled in the art to make and use the methods and devices disclosed in exemplary embodiments of the present disclosure. For purposes of explanation, specific nomenclature is set forth to provide a thorough understanding of the present disclosure. However, it will be apparent to one skilled in the art that these specific details are not required to practice the disclosed exemplary embodiments. Descriptions of specific exemplary embodiments are provided only as representative examples. Various modifications to the exemplary implementations will be readily apparent to one skilled in the art, and the general principles defined herein may be applied to other implementations and applications without departing from the scope of the present disclosure. The present disclosure is not intended to be limited to the implementations shown, but is to be accorded the widest possible scope consistent with the principles and features disclosed herein.

[0026] The present disclosure is directed to exemplary embodiments of a system for increasing heat transfer and decreasing sedimentation in a tube of a heat exchanger. FIG. 1A shows a perspective view of a system 100 for increasing heat transfer and decreasing sedimentation in a tube 150 of a heat exchanger, consistent with one or more exemplary embodiments of the present disclosure. FIG. IB shows a side view of system 100 for increasing heat transfer and decreasing sedimentation in tube 150 of a heat exchanger, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, tube 150 may be a pipe of a heat exchanger or any other pipe. In an exemplary embodiment, tube 150 may be used as a heat interface in a heat exchanger. In an exemplary embodiment, tube 150 may contain a working fluid such as water. As shown in FIG. 1A and FIG. IB, in an exemplary embodiment, system 100 may include a vibrating elastic wire 102. In an exemplary embodiment, vibrating elastic wire 102 may be configured to be disposed inside tube 150 of the heat exchanger. In an exemplary embodiment, vibrating elastic wire 102 may be a string or a strip. In an exemplary embodiment, vibrating elastic wire 102 may be placed along a first axis 157. In an exemplary embodiment, first axis 157 may coincide a main longitudinal axis of tube 150. In an exemplary embodiment, a first end 122 of vibrating elastic wire 102 may be attached to a first end 152 of tube 150. In an exemplary embodiment, a second end 124 of vibrating elastic wire 102 may be attached to a second end 154 of tube 150. In an exemplary embodiment, the tension in vibrating elastic wire 102 may be such that allow vibrating elastic wire 102 to vibrate freely inside tube 150. For purpose of reference, it should be understood that when vibrating elastic wire 102 is disposed inside tube 150 very tightly or very loosely, variable elastic wire 102 may not be able to vibrate freely. In an exemplary embodiment, vibrating elastic wire 102 may be disposed inside tube 150 with a tension between 8 Newton and 20 Newton. In an exemplary embodiment, vibrating elastic wire 102 may be disposed inside tube 150 with a tension equal to 12 Newton.

[0027] In an exemplary embodiment, first end 122 of vibrating elastic wire 102 may be attached to first end 152 of tube 150 by utilizing a first clamp 103. FIG. 2A shows a perspective view of first clamp 103, consistent with one or more exemplary embodiments of the present disclosure. FIG. 2B shows a side view of first clamp 103, consistent with one or more exemplary embodiments of the present disclosure. As shown in FIG. 2A and FIG. 2B, in an exemplary embodiment, first clamp 103 may include a first hollow cylinder 202. In an exemplary embodiment, first hollow cylinder 202 may be fitted inside tube 150. In an exemplary embodiment, an outer diameter 222 of first hollow cylinder 202 may correspond to an inner diameter 153 of tube 150. In an exemplary embodiment, first clamp 103 may further include a first rod 204. In an exemplary embodiment, first rod 204 may be attached to an inner surface 224 of first hollow cylinder 202. In an exemplary embodiment, first end 122 of vibrating elastic wire 102 may be attached to first rod 204. In an exemplary embodiment, first end 122 of vibrating elastic wire 102 may firmly wrapped around first rod 204.

[0028] In an exemplary embodiment, second end 124 of vibrating elastic wire 102 may be attached to second end 154 of tube 150 by utilizing a second clamp 106. In an exemplary embodiment, second clamp 106 may be similar to first clamp 103 in shape, structure, and functionality. FIG. 2C shows a perspective view of second clamp 106, consistent with one or more exemplary embodiments of the present disclosure. FIG. 2D shows a side view of second clamp 106, consistent with one or more exemplary embodiments of the present disclosure. As shown in FIG. 2C and FIG. 2D, in an exemplary embodiment, second clamp 106 may include a second hollow cylinder 203. In an exemplary embodiment, second hollow cylinder 203 may be fitted inside tube 150. In an exemplary embodiment, an outer diameter 232 of second hollow cylinder 203 may correspond to inner diameter 153 of tube 150. In an exemplary embodiment, second clamp 106 may further include a second rod 205. In an exemplary embodiment, second rod 205 may be attached to an inner surface 234 of first hollow cylinder 203. In an exemplary embodiment, second end 124 of vibrating elastic wire 102 may be attached to second rod 205. In an exemplary embodiment, second end 124 of vibrating elastic wire 102 may firmly wrapped around second rod 205.

[0029] As further shown in FIG. IB, in an exemplary embodiment, system 100 may further include a permanent magnet 107. In an exemplary embodiment, permanent magnet 107 may be attached to vibrating elastic wire 102. In an exemplary embodiment, system 100 may further include an electromagnet 108. In an exemplary embodiment, electromagnet 108 may be mounted on an outer surface 156 of tube 150. In an exemplary embodiment, electromagnet

108 may be a U-shaped electromagnet. In an exemplary embodiment, electromagnet 108 may include two poles placed at opposite sides of tube 150. In an exemplary embodiment, electromagnet 108 and permanent magnet 107 may be placed in alignment with each other. In an exemplary embodiment, a distance between electromagnet 108 and first end 152 of tube 150 may be substantially equal to a distance between permanent magnet 107 and first end 122 of vibrating elastic wire 102. In an exemplary embodiment, permanent magnet 107 may be placed at a middle of vibrating elastic wire 102. In an exemplary embodiment, electromagnet 108 may be place at a middle of tube 150.

[0030] As further shown in FIG. 1A and FIG. IB, in an exemplary embodiment, system 100 may further include a AC power supply 109. In an exemplary embodiment, AC power supply

109 may be configured to provide a variable electric current for electromagnet 108. In an exemplary embodiment, when electromagnet 108 is connected to AC power supply 109 and receive variable electric current from AC power supply 109, electromagnet 108 may create a variable magnetic field inside tube 150. In an exemplary embodiment, when electromagnet 108 and permanent magnet 107 are placed in alignment with each other, permanent magnet 107 may be exposed to the variable magnetic field created by electromagnet 108. In an exemplary embodiment, when permanent magnet 107 is placed in and exposed to the variable magnetic field created by electromagnet 108, permanent magnet 107 may vibrate along a second axis 158. In an exemplary embodiment, continuous pole changes in electromagnet 108 may urge permanent magnet 107 to vibrate along a second axis 158. In an exemplary embodiment, second axis 158 may be perpendicular to first axis 157. In an exemplary embodiment, when permanent magnet 107 vibrates along second axis 158 and inside tube 150, vibrating elastic wire 102 may vibrate accordingly with permanent magnet 107. In an exemplary embodiment, vibration of vibrating elastic wire 102 may significantly disrupt the fluid inside the tube and may increase heat transfer and decrease sedimentation inside tube 150 of the heat exchanger.

[0031] In an exemplary embodiment, AC power supply 109 may provide a variable electric current with a predefined frequency for electromagnet 108. In an exemplary embodiment, the predefined frequency may be equal to a natural resonance frequency of vibrating elastic wire 102. In an exemplary embodiment, when the predefined frequency is equal to the natural resonance frequency of vibrating elastic wire 102, it may cause greater heat transfer increase inside tube 150. For example, vibrating elastic wire 102 may have a length of 90 centimeters and a young’s modulus of 80 GPa. Also, vibrating elastic wire 102 may be disposed inside tube 150 with a tension of 12 Newton. In this scenario, the natural resonance frequency of vibrating elastic wire 102 may be equal to 16 Hz. In an exemplary embodiment, the predefined frequency may be set to 16 Hz. In an exemplary embodiment, the predefined frequency may also be set to 16 Hz, 32 Hz, 48 Hz, ....

In an exemplary embodiment, when vibrating elastic wire 102 vibrates with high natural resonance frequencies inside tube 150, an intense turbulence may be imposed to the working fluid inside tube 150. In an exemplary embodiment, this turbulence may significantly decrease sedimentation inside tube 150. Furthermore, it may be understood that when vibrating elastic wire 102 is excited at vibrating elastic wire’s 102 natural frequencies, by a low amount of energy consumption, a great turbulence may be imposed to the fluid inside tube 150. In an exemplary embodiment, by utilizing system 100, the heat transfer may increase at a positive energy level. In an exemplary embodiment, it may mean that by consuming a small amount of energy, heat transfer inside tube 150 may increase by an amount that is much more than the consumed energy. Furthermore, by utilizing system 100, fouling may be prevented in tubes of heat exchangers and the heat transfer may be increased efficiently and economically.

[0032] While the foregoing has described what may be considered to be the best mode and/or other examples, it is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all applications, modifications and variations that fall within the true scope of the present teachings.

[0033] Unless otherwise stated, all measurements, values, ratings, positions, magnitudes, sizes, and other specifications that are set forth in this specification, including in the claims that follow, are approximate, not exact. They are intended to have a reasonable range that is consistent with the functions to which they relate and with what is customary in the art to which they pertain.

[0034] The scope of protection is limited solely by the claims that now follow. That scope is intended and should be interpreted to be as broad as is consistent with the ordinary meaning of the language that is used in the claims when interpreted in light of this specification and the prosecution history that follows and to encompass all structural and functional equivalents. Notwithstanding, none of the claims are intended to embrace subject matter that fails to satisfy the requirement of Ends 101, 102, or 103 of the Patent Act, nor should they be interpreted in such a way. Any unintended embracement of such subject matter is hereby disclaimed.

[0035] Except as stated immediately above, nothing that has been stated or illustrated is intended or should be interpreted to cause a dedication of any component, step, feature, object, benefit, advantage, or equivalent to the public, regardless of whether it is or is not recited in the claims.

[0036] It will be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective spaces of inquiry and study except where specific meanings have otherwise been set forth herein. Relational terms such as first and second and the like may be used solely to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “a” or “an” does not, without further constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0037] The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various implementations. This is for purposes of streamlining the disclosure, and is not to be interpreted as reflecting an intention that the claimed implementations require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed implementation. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.

[0038] While various implementations have been described, the description is intended to be exemplary, rather than limiting and it will be apparent to those of ordinary skill in the art that many more implementations and implementations are possible that are within the scope of the implementations. Although many possible combinations of features are shown in the accompanying figures and discussed in this detailed description, many other combinations of the disclosed features are possible. Any feature of any implementation may be used in combination with or substituted for any other feature or element in any other implementation unless specifically restricted. Therefore, it will be understood that any of the features shown and/or discussed in the present disclosure may be implemented together in any suitable combination. Accordingly, the implementations are not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims.