Electric heater for heating a process fluid with a working fluid

Abstract

An electric heater, systems comprising an electric heater, and methods of heating a process fluid using an electric heater. The electric heater has an electric heating element inside of a housing. A working fluid is passed into the housing and is heated by the electric heating element. The heated working fluid flows within the housing and transfer heat to process fluid contained in conduits extending within the housing of the heater.

Description

RELATED APPLICATIONS

[0001] This application claims priority to United States Provisional Patent Application Ser. No. 63 / 763,559, filed on Feb. 26, 2025, the entire disclosure of which is incorporated herein by reference.FIELD OF THE INVENTION

[0002] This invention relates generally to an electric heater, and more particularly to an electric heater that uses a working fluid to transfer heat from an electric heating element to a process fluid.BACKGROUND OF THE INVENTION

[0003] As a result of the Paris agreement and the Net Zero agreement initiative, there is an increased necessity to reduce carbon footprint and move towards greener fuels, hydrogen firing, and maximizing green electricity heating. Current industry offerings of electric heating are limited and is not suitable for particular heating applications. For example, electric immersion or impedance heating for liquid and two-phase hydrocarbons is not feasible due to variety of risks covering film temperature issues and higher risk of coking.

[0004] Accordingly, it would be desirable to have an electric heater which overcomes the limitations of immersion and impedance heating and is not limited to gas-only applications.SUMMARY OF THE INVENTION

[0005] The present inventors have developed an electric heater, and systems comprising the electric heater, which overcome the disadvantages in existing electric heaters. The present inventors have also developed methods for heating process fluids using an electric heater.

[0006] Therefore, the present invention may be characterized, in at least one aspect, as providing an electric heater for heating a process fluid, the electric heater including: a housing, an inlet for a process fluid and an outlet for the process fluid, an inlet for a working fluid and an outlet for the working fluid, and at least one electrical heating element configured to transfer heat to the working fluid within the housing.

[0007] The housing may further include at least one conduit, the at least one conduit fluidly connected to the inlet for the process fluid and the outlet for the process fluid, wherein each conduit is selected from a group consisting of: vertical conduit, horizontal conduit, serpentine conduit, helical conduit, U- conduit, arbor conduit, I conduit, double I conduit, W conduit, L conduit, and any combination thereof, and wherein each conduit is selected from a group consisting of: bare conduit, extended surface conduit, and any combination thereof.

[0008] The electric heater may further include a plurality of conduits, each conduit fluidically connected to the inlet for the process fluid and the outlet for the process fluid, wherein each conduit is selected from a group consisting of: bare conduit, extended surface conduit, vertical conduit, horizontal conduit, serpentine conduit, helical conduit, U- conduit, arbor conduit, I conduit, double I conduit, W conduit, L conduit, and any combination thereof.

[0009] The electric heater may further include a plurality of electrical heating elements.

[0010] The working fluid may be selected from a group consisting of: air, steam, carbon dioxide, sulfur dioxide, other gaseous, inert or polar molecules, and any combination thereof.

[0011] The present invention may be also characterized, in at least another aspect, as providing a system, the system including: an electric heater for heating a process fluid, the electric heater including: a housing, an inlet for a process fluid and an outlet for the process fluid, an inlet for a working fluid and an outlet for the working fluid, and at least one electrical heating element configured to transfer heat to the working fluid within the housing; and at least one recirculation loop, the at least one recirculation loop including: at least one conduit, the at least one conduit fluidly connected to the inlet for the working fluid and the outlet for the working fluid.

[0012] The at least one recirculation loop may further include at least one heater, the at least one heater configured to heat the working fluid in the at least one recirculation loop.

[0013] The at least one recirculation loop may further include at least one element from a group consisting of a fan, a blower, a turbine, a compressor, a pump, and any combination thereof, wherein the at least one recirculation loop comprises a negative pressure loop.

[0014] The system may further include at least one fired heater configured to heat the process fluid, wherein the at least one fired heater is arranged in series with the electric heater, or wherein the at least one fired heater is arranged in parallel with the electric heater.

[0015] The system may further include a second electric heater for heating the process fluid, the second heater including a housing, an inlet for the process fluid and an outlet for the process fluid, an inlet for the working fluid and an outlet for the working fluid, and at least one electrical heating element configured to transfer heat to the working fluid within the housing, wherein the electric heater and the second electric heater are arranged in series, or wherein the electric heater and the second electric heater are arranged in parallel.

[0016] The present invention may be further characterized, in at least another aspect, as providing a method of heating a process fluid, the method comprising: passing a working fluid into an inlet for a working fluid in a housing of an electrical heater, the housing including a first electrical heating element; passing an electric current into the first electrical heating element to heat the working fluid within the electrical heater to provide a heated working fluid; passing a process fluid into an inlet for a process of the electrical heater; and heating the process fluid within the electrical heater with the heated working fluid to provide a heated process fluid and a cooled working fluid.

[0017] The method may include passing the cooled working fluid to at least one recirculation loop, the at least one recirculation loop including at least one conduit, the at least one conduit fluidly connected to an outlet for the working fluid of the electric heater and the working fluid inlet; and passing the cooled working fluid to the inlet for the working fluid using the at least one conduit.

[0018] The at least one recirculation loop further may include at least one heater, the method may include heating the cooled working fluid using the at least one heater to provide a preheated working fluid; and passing the preheated working fluid to the inlet for the working fluid using the at least one conduit.

[0019] The method may include passing an electric current into a second electrical heating element to reheat the working fluid within the electrical heater to provide a reheated working fluid; and heating the process fluid within the electrical heater with the reheated working fluid.

[0020] Additional aspects, embodiments, and details of the invention, all of which may be combinable in any manner, are set forth in the following detailed description of the invention.DETAILED DESCRIPTION OF THE DRAWINGS

[0021] One or more exemplary embodiments of the present invention will be described below in conjunction with the following drawing figures, in which:

[0022] FIG. 1 shows a schematic depiction of an electric heater according to one or more aspects of the present invention.

[0023] FIG. 2 shows a schematic depiction of system according to one or more aspects of the present invention.

[0024] FIG. 3 shows a schematic depiction of system according to one or more aspects of the present invention.

[0025] FIG. 4 shows a schematic depiction of an electric heater according to one or more aspects of the present invention.

[0026] FIG. 5 shows a schematic depiction of system according to one or more aspects of the present invention.

[0027] FIG. 5 shows a process flow diagram according to one or more aspects of the present invention.

[0028] FIG. 6 shows a graph demonstrating the relationship between concentration of an exemplary polar molecule in the working fluid and shock / radiative heat transfer of the working fluid.

[0029] FIG. 7 shows a graph demonstrating the relationship between concentration of an exemplary polar molecule in the working fluid and heat transfer of the working fluid

[0030] FIG. 8 shows a graph demonstrating the relationship between the mass velocity of the working fluid and heat transfer of the working fluid.

[0031] It should be appreciated and understood by those of ordinary skill in the art that various other components such as valves, pumps, etc. were not shown in the drawings as it is believed that the specifics of same are well within the knowledge of those of ordinary skill in the art and a description of same is not necessary for practicing or understating the embodiments of the present invention.DETAILED DESCRIPTION OF THE INVENTION

[0032] As mentioned above, an electric heater, systems comprising an electric heater, and methods of heating a process fluid using an electric heater have been invented.

[0033] The electric heater, and systems comprising the electric heater, may be used to heat a process fluid. The electric heater may function as an alternative heating source, i.e., as an alternative to fired heaters, or may be used in systems with fired heaters. In some embodiments, electric heaters described herein may be used in systems with fired heaters when fired heaters are required for consumption of off-gasses (or any other gaseous fuel) and / or internally generated liquid fuels produced by a system. Also described herein are methods of heating a process fluid using an electric heater.

[0034] With these general principles in mind, one or more embodiments of the present invention will be described with the understanding that the following description is not intended to be limiting.

[0035] Turning to FIGS. 1 to 5, various embodiments of the present invention will be described which are utilized to heat a process fluid.

[0036] Turning to FIG. 1, an exemplary electric heater 100 will be described which is utilized to heat a process fluid. Electric heater 100 may include a housing 10. The electric heater 100 may include an inlet for a process fluid 12 and an outlet for the process fluid 14. The electric heater 100 may include an inlet for a working fluid 16 and an outlet for the working fluid 18. The electric heater 100 may include at least one electrical heating element 20 configured to transfer heat to the working fluid within the housing 10. Although specific components are shown in FIG. 1 as being included in electric heater 100, electric heater 100 may include more or fewer components. For example, electric heater 100 may include a plurality of electrical heating elements 20. Electric heater 100 may also integrate or separate various components shown in FIG. 1. The electric heater 100 may be part of, or integrated into, any system which require the heating of a process fluid, as described in more detail herein.

[0037] As shown in FIG. 1, housing 10 may further comprise at least one conduit 22, the conduit 22 fluidly connected to the inlet for the process fluid 12 and the outlet for the process fluid 14. As described in more detail herein, housing 10 may comprise a plurality of conduits 22, each conduit fluidically connected an inlet for the process fluid and to an outlet for the process fluid. Each conduit 22 may be, but is not limited to, a vertical conduit, a horizontal conduit, a serpentine conduit, a helical conduit, a U- conduit, an arbor conduit, an I conduit, a double I conduit, a W conduit, an L conduit, and any combination thereof. Each conduit 22 may be a bare conduit, an extended surface conduit, and any combination thereof. In some embodiments, conduit 22 may be configured to enhance heat transfer between the process fluid and the working fluid. For example, conduit 22 may include one or more internal layers or external layers or coatings of known heat transfer materials, including, but not limited to high flux coatings, internals to increase turbulence and like.

[0038] Still referring to FIG. 1, the housing 10 may be made of metal, refractory, ceramic, or a combination thereof. The housing 10 may be configured to prevent heat loss. For example, housing 10 may include one or more internal layers or external layers to further prevent heat loss. In some embodiments, housing 10 may include one or more internal or external layers of known insulating materials, including, but not limited to, refractory, fiberglass, mineral wool, cellulose, polymeric foams or panels, and combinations thereof.

[0039] The at least one electrical heating element 20 may be disposed of in any suitable manner within housing 10. For example, electrical heating element 20 may be disposed along the walls, ceiling, and / or floor of the housing 10. The at least one electrical heating element 20 may be suspended within the enclosure. The electrical heating element 20 may be, but is not limited to, a wire, a coil, a cartridge, a tube, a panel, and combinations thereof. The electrical heating element 20 may be a metal, an alloy, a semiconductor, a ceramic, and combinations thereof. In some embodiments, electric heating element 20 may be configured to enhance heat transfer between the heating element and the working fluid. For example, electrical heating element 20 may include one or more layers, coatings, or sheaths, the one or more layers, coatings, or sheaths may be of known materials to: enhance heat transfer including, but not limited to, high flux coatings, protect the electrical heating element 20 from corrosion, and so forth. The electrical heating element 20 may be a bare surface, an extended surface, and combinations thereof.

[0040] The electric heater 100 of FIG. 1 may be used in a method for heating a process fluid. In this embodiment, a working fluid 50 may be passed into the inlet for the working fluid 16 of housing 10. An electric current (not shown) may be passed to electrical heating element 20 to heat the working fluid 50 within the housing 10 to provide a heated working fluid 52. A process fluid 54 may be passed into the inlet for the process fluid 12 of housing 10. The process fluid 54 may be heated with the heated working fluid 52 to provide a heated process fluid 56 and a cooled working fluid 58.

[0041] The working fluid 50 may be any fluid that transfers heat. In some embodiments, the working fluid 50 is selected from a group consisting of air, steam, carbon dioxide, sulfur dioxide, other gaseous, inert or polar molecules, and any combination thereof. In some embodiments, one or more additives may be added to the working fluid 50 to enhance heat transfer including, but not limited to, helium, argon and xenon. In some embodiments, working fluid 50 may be in the gaseous or vapor state. The process fluid 54 is any fluid which a user of electric heater 100 desires to be heated.

[0042] Without being bound by theory, it is believed that the process fluid 54 is heated by both convective heat transfer and radiative heat transfer. The process fluid 54 is primarily heated through convective heat transfer from the heated working fluid 52. By “primarily” it is meant at least at least 60%, at least 90%, or at least 95% of the heat transfer is through convective heat transfer. The process fluid 54 is also slightly heated by radiative heat transfer from the at least one electrical heating element 20 and molecular radiation of the heated working fluid 52. By “slightly” it is meant less than 40%, less than 10%, or less than 5% of the heat transfer is through radiative heat transfer.

[0043] Turning now to FIG. 2, an exemplary system 2000 is shown. As described herein, electric heaters of the present invention may be part of, or integrated into, any system which requires the heating of a process fluid, including system 2000. As shown in FIG. 2, system 2000 may include electric heater 200 for heating a process fluid. While FIG. 2 shows one electric heater 200, the number of electric heaters 200 is not limited. The system 2000 may a plurality of electric heaters 200. In this embodiment, the plurality of electric heaters 200 may be arranged in series or in parallel.

[0044] In some embodiments, electric heater 200 may be of the type as described herein. Electric heater 200 may include a housing 210, an inlet for a process fluid (not shown), an outlet for the process fluid (not shown), an inlet for a working fluid (not shown), and an outlet for the working fluid (not shown). Electric heater 200 may include electrical heating elements 220 configured to heat the working fluid within housing 210. While FIG. 2 shows two electrical heating elements 220, the number of electrical heating elements is not limited. In some embodiments, housing 210 may further include at least one conduit (not shown), the at least one conduit fluidly connected to the inlet for the process fluid and the outlet for the process fluid.

[0045] System 2000 may further include at least one recirculation loop 230. The recirculation loop 230 may include at least one conduit (not shown) fluidly connected to the inlet for the working fluid and the outlet for the working fluid. The recirculation loop 230 may further comprise one or more additional elements, including a heater, a fan, a blower, a turbine, a compressor, a pump, and any combination thereof. These additional elements may be used to treat the working fluid as it is passed through recirculation loop 230. As shown in the specific example of FIG. 2, the recirculation loop 230 includes a heater 222 and a compressor 224 as the additional element. FIG. 2 shows the specific example where the additional element 224 is a compressor, as discussed above, other additional elements may be in recirculation loop 230. Further, while FIG. 2 shows that the compressor 224 is upstream of heater 222, the reverse order is contemplated. The recirculation loop 230 may be a negative pressure loop or a positive pressure loop.

[0046] Still referring to FIG. 2, the system 2000 may be used to heat a process fluid. In this embodiment, a working fluid 250 may be passed into the inlet for the working fluid of housing 210. An electric current (not shown) may be passed to heating elements 220 to heat the working fluid 250 within the housing 210 to provide a heated working fluid (not shown). A process fluid 254 may be passed into the inlet for the process fluid of housing 210. The process fluid 254 may be heated with the heated working fluid to provide a heated process fluid 256 and a cooled working fluid 258.

[0047] The cooled working fluid 258 may enter the recirculation loop 230 to be recirculated to the inlet for the working fluid in electric heater 200. In this way, cooled working fluid 258 may be recycled in system 2000 to heat a process fluid. Cooled working fluid 258 may be passed to optional cooler or heat sink 226 to further cool the cooled working fluid 258. In the recirculation loop 230, cooled working fluid 258 may be passed to compressor 224 to provide a compressed cooled working fluid 260. The compressed cooled working fluid 260 may be passed to heater 222 to provide heated compressed working fluid 262. Heated compressed working fluid 262 is returned to electric heater 200 via recirculation loop 230 as the working fluid 250.

[0048] Turning now to FIG. 3, an exemplary system 3000 for heating a process fluid is shown. As described herein, electric heaters of the present invention may be part of, or integrated into, any system which requires the heating of a process fluid, including system 3000. As shown in FIG. 3, system 3000 may include electric heater 300 for heating a process fluid. In some embodiments, electric heater 300 may be of the type as described herein. System 3000 may further include at least one recirculation loop 330. The recirculation loop 330 may be of the type as described herein. As shown in the specific example of FIG. 3, the recirculation loop 330 includes a heater 322 and a fan 326.

[0049] As shown in FIG. 3, system 3000 further includes fired heater 370 which is fluidly connected to electric heater 300. By “fired heater” what is meant is a heater which combusts fuel to produce heat. The fired heater 370 may be arranged in series or in parallel with the electric heater 300. In some embodiments, electric heater 300 may preheat a process fluid to be further heated by fired heater 370. In other embodiments, electric heater 300 may serve as a back-up heater when fired heater 370 is being cleaned, being repaired, and so forth.

[0050] The system 3000 may be used to heat a process fluid 354 using an electric heater 300 and a fired heater 370. In this embodiment, a working fluid 350 may be passed into electric heater 300. An electric current (not shown) may be passed to electrical heating element 320 to heat the working fluid 350 to provide a heated working fluid (not shown). In this embodiment, process fluid 354 is passed to fired heater 370 to provide preheated process fluid 380 heated to a first temperature T1. Preheated process fluid 380 may be passed into electric heater 300. The preheated process fluid 380 may be further heated with the heated working fluid within electric heater 300 to provide a heated process fluid 356 at a second temperature T2 and a cooled working fluid 358. Heated process fluid 356 may be recycled back to fired heater 370 to provide a heated process fluid 382 at a third temperature T3. Alternatively, heated process fluid 356 may exit system 3000 at temperature T2 as heated process fluid 384.

[0051] Still referring to FIG. 3, the cooled working fluid 358 may enter recirculation loop 330 to be recirculated to the inlet for the working fluid in electric heater 300. In this way, cooled working fluid 358 may be recycled in system 3000 to heat a process fluid. In the recirculation loop 330, cooled working fluid 358 may be passed to heater 322 to provide heated working fluid 364. Heated working fluid 364 may be passed to fan 326 to provide fanned heated working fluid 366. Fanned heated working fluid 366 is returned to electric heater 300 via recirculation loop 330 as the working fluid 350. The heater 322 may alternatively be placed downstream of fan 326.

[0052] Turning now to FIG. 4, an exemplary electric heater 400 will be described which is utilized to heat a process fluid. Electric heater 400 may include a housing 410. Electric heater 400 may include a plurality of inlets for a process fluid 412 and a plurality of outlets for the process fluid 414. The electric heater 400 may include an inlet for a working fluid 416 and an outlet for the working fluid 418. The electric heater 400 may include a plurality of electrical heating elements 420 configured to transfer heat to the working fluid within the housing 410. Housing 410 may further comprise a plurality of conduits 422. The conduits 422 may be fluidly connected to the plurality of inlets for a process fluid 412 and the plurality of outlets for the process fluid 414.

[0053] The electric heater 400 of FIG. 4 may be used in a method for heating a process fluid. In this embodiment, a working fluid 450 may be passed into the inlet for the working fluid 416 of housing 410. An electric current (not shown) may be passed to electrical heating elements 420 to heat the working fluid 450 within the housing 410 to provide a heated working fluid 452. A process fluid 454 may be passed into the plurality of inlets for a process fluid 412 of housing 410. The process fluid 454 may be heated with the heated working fluid 452 to provide a heated process fluid 456 and a cooled working fluid 458. In the specific embodiment shown in FIG. 4, the process fluid 454 flows counter currently to heated working fluid 452, however although not depicted as such, the process fluid 454 may be co-current flow or cross flow. Without being bound by theory, it is believed that having the process fluid 454 flow counter currently to heated process fluid 456 increases the heat transfer between process fluid 454 and heated working fluid 452.

[0054] Turning now to FIG. 5, an exemplary system 5000 for heating a process fluid is shown. As shown in FIG. 5, system 5000 may include electric heater 500 for heating a process fluid. In some embodiments, electric heater 500 may be of the type as described herein. Electric heater 500 may include a housing 510 and a plurality of electrical heating elements 520. System 5000 may further include at least one recirculation loop 530. The recirculation loop 530 may be of the type as described herein. As shown in the specific example of FIG. 5, recirculation loop 530 includes a heater 522, a compressor 524 as the additional element, and a filter 528.

[0055] The system 5000 may be used to heat a process fluid 554 using electric heater 500. In this specific example, a working fluid 550 is introduced into housing 510. Working fluid 550 flows through housing 510, and in doing so, flows past a plurality of electrical heating elements 520, providing a heated working fluid. At the same time, process fluid 554 is introduced and flows through into housing 510 counter currently to the heated working fluid. While FIG. 5, shows process fluid 554 moving counter currently to heated working fluid, as mentioned above, co-current flow or cross flow is also contemplated. As described in more detail herein, as process fluid 554 passes the heated working fluid counter currently, the heat transfers from heated working fluid to process fluid 554 to provide a heated process fluid 556 and a cooled working fluid 558.

[0056] As shown in FIG. 5, a working fluid 550 may enter housing 510 of electric heater 500. Initially, working fluid 550 may have an initial temperature T1 of 598.2 ºF (314.56 ºC) at point (A). As the working fluid 550 flows past electrical heating element 520 it is heated to at temperature T2 to provide a first heated working fluid at point (B), which may be 1150 ºF (621.11 ºC). When the first heated working fluid flows past process fluid 554, which is flowing counter currently in a conduit (not shown) through housing 510, at least some heat is transferred from first heated working fluid to process fluid, providing a first cooled working fluid and a heated process fluid. At point (C), first cooled working fluid may have a temperature T3 of 677.6 ºF (358.67 ºC). As first cooled working fluid flows past another electrical heating element 520 it is reheated to temperature T2 at point (D) to provide a second heated working fluid. When the second heated working fluid flows past slightly heated process fluid, at least some heat is transferred from second heated working fluid to heated process fluid, providing a second cooled working fluid and a further heated process fluid. At point (E), the second cooled working fluid may have a temperature T4 of 684 ºF (362.22 ºC). As second cooled working fluid flows past another electrical heating element 520 it is reheated to temperature T2 at point (F) to provide a third heated working fluid. When the third heated working fluid flows past further heated process fluid, at least some heat is transferred from third heated working fluid to process fluid 554, providing a third cooled working fluid and a further heated process fluid. At point (G), the second cooled working fluid may have a temperature T4 of 670.50 ºF (354.72 ºC). As third cooled working fluid flows past another electrical heating element 520 it is reheated to temperature T2 at point (H) to provide a fourth heated working fluid. When the fourth heated working fluid flows past further heated process fluid, at least some heat is transferred from fourth heated working fluid to further heated process fluid, providing a fourth cooled working fluid and heated process fluid 556. At point (I), the fourth cooled working fluid may have a temperature T5 of 598.20 ºF (314.56 ºC). The temperature values in this example are for illustrative purposes only and are not intended to be limiting.

[0057] Still referring to FIG. 5, fourth cooled working fluid may exit housing 510 as a cooled working fluid 558 and enter recirculation loop 530. Recirculation loop 530 may treat or process cooled working fluid 558 to be reused as working fluid 550, to be vented to the atmosphere, or a combination thereof. In some embodiments, at least a portion of the cooled working fluid 558 may be passed to filter or scrubber 528 to provide a cleaned working fluid 568, which may be vented to the atmosphere. The remainder of cooled working fluid 558 may be passed to compressor 524 to provide compressed cooled working fluid 560. The compressed cooled working fluid 560 may be passed to heater 522 to provide heated compressed working fluid 562. Heated compressed working fluid 562 may enter electric heater 500 as working fluid 550. In some embodiments, recirculation loop 530 may include working fluid feed 570 to supplement working fluid 550 as necessary.

[0058] As shown in FIG. 5, in this embodiment, process fluid 554 enters housing 510 at point (J) at a temperature T0. In this example, temperature T0 may be 512.90 ºF (267.17 ºC). As process fluid 554 flows counter currently to working fluid 550 throughout housing 510 of, it is continuously and incrementally heated to provide heated process fluid 556. Heated process fluid 556 may leave electric heater 200 and have a temperature of 565 ºF (296.11 ºC) at point (K). The temperature values in this example are for illustrative purposes only and are not intended to be limiting.

[0059] The systems described herein may include a controller or a computing device comprising a processing and a memory which has stored therein computer-executable instructions for implementing the processes described herein. The processing unit may comprise any suitable devices configured to cause a series of steps to be performed so as to implement the method such that instructions, when executed by the computing device or other programmable apparatus, may cause the functions / acts / steps specified in the methods described herein to be executed. The processing unit may comprise, for example, any type of general-purpose microprocessor or microcontroller, a digital signal processing (DSP) processor, a central processing unit (CPU), an integrated circuit, a field programmable gate array (FPGA), a reconfigurable processor, other suitably programmed or programmable logic circuits, or any combination.

[0060] The memory may be any suitable known or other machine-readable storage medium. The memory may comprise non-transitory computer readable storage medium such as, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. The memory may include a suitable combination of any type of computer memory that is located either internally or externally to the device such as, for example, random-access memory (RAM), read-only memory (ROM), compact disc read-only memory (CDROM), electro-optical memory, magneto-optical memory, erasable programmable read-only memory (EPROM), and electrically-erasable programmable read-only memory (EEPROM), Ferroelectric RAM (FRAM) or the like. The memory may comprise any storage means (e.g., devices) suitable for retrievably storing the computer-executable instructions executable by processing unit.

[0061] Computer-executable instructions may be in many forms, including modules, executed by one or more computers or other devices. Generally, modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. Typically, the functionality of the modules may be combined or distributed as desired in various embodiments.

[0062] It will be appreciated that the systems and devices and components thereof may utilize communication through any of various network protocols such as TCP / IP, Ethernet, FTP, HTTP and the like, and / or through various wireless communication technologies such as GSM, CDMA, Wi-Fi, and WiMAX, is and the various computing devices described herein may be configured to communicate using any of these network protocols or technologies.

[0063] Any of the above lines, conduits, units, devices, vessels, surrounding environments, zones or similar may be equipped with one or more monitoring components including sensors, measurement devices, data capture devices or data transmission devices. Signals, process or status measurements, and data from monitoring components may be utilized to monitor conditions in, around, and on process equipment. Signals, measurements, and / or data generated or recorded by monitoring components may be collected, processed, and / or transmitted through one or more networks or connections that may be private or public, general or specific, direct or indirect, wired or wireless, encrypted or not encrypted, and / or combination(s) thereof; the specification is not intended to be limiting in this respect.

[0064] Signals, measurements, and / or data generated or recorded by monitoring components may be transmitted to one or more computing devices or systems. Computing devices or systems may include at least one processor and memory storing computer-readable instructions that, when executed by the at least one processor, cause the one or more computing devices to perform a process that may include one or more steps.

[0065] For example, the one or more computing devices may be configured to receive, from one or more monitoring component, data related to at least one piece of equipment associated with the process. The one or more computing devices or systems may be configured to analyze the data. Based on analyzing the data, the one or more computing devices or systems may be configured to determine one or more recommended adjustments to one or more parameters of one or more processes described herein. The one or more computing devices or systems may be configured to transmit encrypted or unencrypted data that includes the one or more recommended adjustments to the one or more parameters of the one or more processes described herein.

[0066] It should be appreciated and understood by those of ordinary skill in the art that various other components such as valves, pumps, filters, coolers, etc. were not shown in the drawings as it is believed that the specifics of same are well within the knowledge of those of ordinary skill in the art and a description of same is not necessary for practicing or understanding the embodiments of the present invention.Experiments

[0067] The composition of the working fluid, and its control, may impact heat transfer. FIGS. 6 and 7 shows increasing the concentration of polar molecules in the working fluid can result in increased shock / radiative and total heat transfer of the working fluid respectively. Polar molecules increase radiant heat transfer. Thus, working fluids having or comprising polar molecules (e.g., water), will have increased radiant heat transfer between electrical heating elements and the working fluid. Thus, working fluids having or comprising polar molecules increase the heat-carrying capacity of the working fluid, and an increased heat transfer may be achieved from the same surface area at the same circulation rate.

[0068] The mass velocity modulation of the working fluid can also enhance heat transfer of the working fluid. FIG. 8 shows a co-relation of how increasing the mass velocity of working fluid can increase heat transfer, even while inlet temperature and process coil surface area remain the same.Specific Embodiments

[0069] While the following is described in conjunction with specific embodiments, it will be understood that this description is intended to illustrate and not limit the scope of the preceding description and the appended claims.

[0070] A first embodiment of the invention is an electric heater for heating a process fluid, the electric heater comprising a housing, an inlet for a process fluid and an outlet for the process fluid, an inlet for a working fluid and an outlet for the working fluid, and at least one electrical heating element configured to transfer heat to the working fluid within the housing. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, the housing further comprising at least one conduit, the at least one conduit fluidly connected to the inlet for the process fluid and the outlet for the process fluid. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, further comprising a plurality of conduits, each conduit fluidically connected to the inlet for the process fluid and the outlet for the process fluid. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, wherein each conduit is selected from a group consisting of bare conduit, extended surface conduit, vertical conduit, horizontal conduit, serpentine conduit, helical conduit, U- conduit, arbor conduit, I conduit, double I conduit, W conduit, L conduit, and any combination thereof. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, further comprising a plurality of electrical heating elements. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, wherein the working fluid is selected from a group consisting of air, steam, carbon dioxide, sulfur dioxide, other gaseous, inert or polar molecules, and any combination thereof.

[0071] A second embodiment of the invention is a system, the system comprising a system for heating a process fluid, the system including a housing, an inlet for a process fluid and an outlet for the process fluid, an inlet for a working fluid and an outlet for the working fluid, and at least one electrical heating element configured to transfer heat to the working fluid within the housing; and at least one recirculation loop, the at least one recirculation loop including at least one conduit, the at least one conduit fluidly connected to the inlet for the working fluid and the outlet for the working fluid. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, the at least one recirculation loop further comprising at least one heater, the at least one heater configured to heat the working fluid in the at least one recirculation loop. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, the at least one recirculation loop further comprising at least one element from a group consisting of a fan, a blower, a turbine, a compressor, a pump, and any combination thereof. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, wherein the at least one recirculation loop comprises a negative pressure loop. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, further comprising at least one fired heater configured to heat the process fluid. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, wherein the at least one fired heater is arranged in series with the system. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, wherein the at least one fired heater is arranged in parallel with the system. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, further comprising a second system for heating the process fluid, the second heater including a housing, an inlet for the process fluid and an outlet for the process fluid, an inlet for the working fluid and an outlet for the working fluid, and at least one electrical heating element configured to transfer heat to the working fluid within the housing. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, wherein the system and the second system are arranged in series. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, wherein the system and the second system are arranged in parallel.

[0072] A third embodiment of the invention is a method of heating a process fluid, the method comprising passing a working fluid into an inlet for a working fluid in a housing of an electrical heater, the housing including a first electrical heating element; passing an electric current into the first electrical heating element to heat the working fluid within the electrical heater to provide a heated working fluid; passing a process fluid into an inlet for a process of the electrical heater; and heating the process fluid within the electrical heater with the heated working fluid to provide a heated process fluid and a cooled working fluid. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the third embodiment in this paragraph, the method further comprising passing the cooled working fluid to at least one recirculation loop, the at least one recirculation loop including at least one conduit, the at least one conduit fluidly connected to an outlet for the working fluid of the system and the working fluid inlet; and passing the cooled working fluid to the inlet for the working fluid using the at least one conduit. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the third embodiment in this paragraph, the at least one recirculation loop further comprising at least one heater, the method further comprising heating the cooled working fluid using the at least one heater to provide a preheated working fluid; and passing the preheated working fluid to the inlet for the working fluid using the at least one conduit. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the third embodiment in this paragraph, further comprising passing an electric current into a second electrical heating element to reheat the working fluid within the electrical heater to provide a reheated working fluid; and heating the process fluid within the electrical heater with the reheated working fluid.

[0073] Without further elaboration, it is believed that using the preceding description that one skilled in the art can utilize the present invention to its fullest extent and easily ascertain the essential characteristics of this invention, without departing from the spirit and scope thereof, to make various changes and modifications of the invention and to adapt it to various usages and conditions. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limiting the remainder of the disclosure in any way whatsoever, and that it is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0074] In the foregoing, all temperatures are set forth in degrees Celsius and, all parts and percentages are by weight, unless otherwise indicated.

[0075] While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.

Examples

specific embodiments

[0069]While the following is described in conjunction with specific embodiments, it will be understood that this description is intended to illustrate and not limit the scope of the preceding description and the appended claims.

[0070]A first embodiment of the invention is an electric heater for heating a process fluid, the electric heater comprising a housing, an inlet for a process fluid and an outlet for the process fluid, an inlet for a working fluid and an outlet for the working fluid, and at least one electrical heating element configured to transfer heat to the working fluid within the housing. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, the housing further comprising at least one conduit, the at least one conduit fluidly connected to the inlet for the process fluid and the outlet for the process fluid. An embodiment of the invention is one, any or all of prior embodiments in this p...

RELATED APPLICATIONS

[0001] This application claims priority to United States Provisional Patent Application Ser. No. 63 / 763,559, filed on Feb. 26, 2025, the entire disclosure of which is incorporated herein by reference.FIELD OF THE INVENTION

[0002] This invention relates generally to an electric heater, and more particularly to an electric heater that uses a working fluid to transfer heat from an electric heating element to a process fluid.BACKGROUND OF THE INVENTION

[0003] As a result of the Paris agreement and the Net Zero agreement initiative, there is an increased necessity to reduce carbon footprint and move towards greener fuels, hydrogen firing, and maximizing green electricity heating. Current industry offerings of electric heating are limited and is not suitable for particular heating applications. For example, electric immersion or impedance heating for liquid and two-phase hydrocarbons is not feasible due to variety of risks covering film temperature issues and higher risk of coking.

[0004] Accordingly, it would be desirable to have an electric heater which overcomes the limitations of immersion and impedance heating and is not limited to gas-only applications.SUMMARY OF THE INVENTION

[0005] The present inventors have developed an electric heater, and systems comprising the electric heater, which overcome the disadvantages in existing electric heaters. The present inventors have also developed methods for heating process fluids using an electric heater.

[0006] Therefore, the present invention may be characterized, in at least one aspect, as providing an electric heater for heating a process fluid, the electric heater including: a housing, an inlet for a process fluid and an outlet for the process fluid, an inlet for a working fluid and an outlet for the working fluid, and at least one electrical heating element configured to transfer heat to the working fluid within the housing.

[0007] The housing may further include at least one conduit, the at least one conduit fluidly connected to the inlet for the process fluid and the outlet for the process fluid, wherein each conduit is selected from a group consisting of: vertical conduit, horizontal conduit, serpentine conduit, helical conduit, U- conduit, arbor conduit, I conduit, double I conduit, W conduit, L conduit, and any combination thereof, and wherein each conduit is selected from a group consisting of: bare conduit, extended surface conduit, and any combination thereof.

[0008] The electric heater may further include a plurality of conduits, each conduit fluidically connected to the inlet for the process fluid and the outlet for the process fluid, wherein each conduit is selected from a group consisting of: bare conduit, extended surface conduit, vertical conduit, horizontal conduit, serpentine conduit, helical conduit, U- conduit, arbor conduit, I conduit, double I conduit, W conduit, L conduit, and any combination thereof.

[0009] The electric heater may further include a plurality of electrical heating elements.

[0010] The working fluid may be selected from a group consisting of: air, steam, carbon dioxide, sulfur dioxide, other gaseous, inert or polar molecules, and any combination thereof.

[0011] The present invention may be also characterized, in at least another aspect, as providing a system, the system including: an electric heater for heating a process fluid, the electric heater including: a housing, an inlet for a process fluid and an outlet for the process fluid, an inlet for a working fluid and an outlet for the working fluid, and at least one electrical heating element configured to transfer heat to the working fluid within the housing; and at least one recirculation loop, the at least one recirculation loop including: at least one conduit, the at least one conduit fluidly connected to the inlet for the working fluid and the outlet for the working fluid.

[0012] The at least one recirculation loop may further include at least one heater, the at least one heater configured to heat the working fluid in the at least one recirculation loop.

[0013] The at least one recirculation loop may further include at least one element from a group consisting of a fan, a blower, a turbine, a compressor, a pump, and any combination thereof, wherein the at least one recirculation loop comprises a negative pressure loop.

[0014] The system may further include at least one fired heater configured to heat the process fluid, wherein the at least one fired heater is arranged in series with the electric heater, or wherein the at least one fired heater is arranged in parallel with the electric heater.

[0015] The system may further include a second electric heater for heating the process fluid, the second heater including a housing, an inlet for the process fluid and an outlet for the process fluid, an inlet for the working fluid and an outlet for the working fluid, and at least one electrical heating element configured to transfer heat to the working fluid within the housing, wherein the electric heater and the second electric heater are arranged in series, or wherein the electric heater and the second electric heater are arranged in parallel.

[0016] The present invention may be further characterized, in at least another aspect, as providing a method of heating a process fluid, the method comprising: passing a working fluid into an inlet for a working fluid in a housing of an electrical heater, the housing including a first electrical heating element; passing an electric current into the first electrical heating element to heat the working fluid within the electrical heater to provide a heated working fluid; passing a process fluid into an inlet for a process of the electrical heater; and heating the process fluid within the electrical heater with the heated working fluid to provide a heated process fluid and a cooled working fluid.

[0017] The method may include passing the cooled working fluid to at least one recirculation loop, the at least one recirculation loop including at least one conduit, the at least one conduit fluidly connected to an outlet for the working fluid of the electric heater and the working fluid inlet; and passing the cooled working fluid to the inlet for the working fluid using the at least one conduit.

[0018] The at least one recirculation loop further may include at least one heater, the method may include heating the cooled working fluid using the at least one heater to provide a preheated working fluid; and passing the preheated working fluid to the inlet for the working fluid using the at least one conduit.

[0019] The method may include passing an electric current into a second electrical heating element to reheat the working fluid within the electrical heater to provide a reheated working fluid; and heating the process fluid within the electrical heater with the reheated working fluid.

[0020] Additional aspects, embodiments, and details of the invention, all of which may be combinable in any manner, are set forth in the following detailed description of the invention.DETAILED DESCRIPTION OF THE DRAWINGS

[0021] One or more exemplary embodiments of the present invention will be described below in conjunction with the following drawing figures, in which:

[0022] FIG. 1 shows a schematic depiction of an electric heater according to one or more aspects of the present invention.

[0023] FIG. 2 shows a schematic depiction of system according to one or more aspects of the present invention.

[0024] FIG. 3 shows a schematic depiction of system according to one or more aspects of the present invention.

[0025] FIG. 4 shows a schematic depiction of an electric heater according to one or more aspects of the present invention.

[0026] FIG. 5 shows a schematic depiction of system according to one or more aspects of the present invention.

[0027] FIG. 5 shows a process flow diagram according to one or more aspects of the present invention.

[0028] FIG. 6 shows a graph demonstrating the relationship between concentration of an exemplary polar molecule in the working fluid and shock / radiative heat transfer of the working fluid.

[0029] FIG. 7 shows a graph demonstrating the relationship between concentration of an exemplary polar molecule in the working fluid and heat transfer of the working fluid

[0030] FIG. 8 shows a graph demonstrating the relationship between the mass velocity of the working fluid and heat transfer of the working fluid.

[0031] It should be appreciated and understood by those of ordinary skill in the art that various other components such as valves, pumps, etc. were not shown in the drawings as it is believed that the specifics of same are well within the knowledge of those of ordinary skill in the art and a description of same is not necessary for practicing or understating the embodiments of the present invention.DETAILED DESCRIPTION OF THE INVENTION

[0032] As mentioned above, an electric heater, systems comprising an electric heater, and methods of heating a process fluid using an electric heater have been invented.

[0033] The electric heater, and systems comprising the electric heater, may be used to heat a process fluid. The electric heater may function as an alternative heating source, i.e., as an alternative to fired heaters, or may be used in systems with fired heaters. In some embodiments, electric heaters described herein may be used in systems with fired heaters when fired heaters are required for consumption of off-gasses (or any other gaseous fuel) and / or internally generated liquid fuels produced by a system. Also described herein are methods of heating a process fluid using an electric heater.

[0034] With these general principles in mind, one or more embodiments of the present invention will be described with the understanding that the following description is not intended to be limiting.

[0035] Turning to FIGS. 1 to 5, various embodiments of the present invention will be described which are utilized to heat a process fluid.

[0036] Turning to FIG. 1, an exemplary electric heater 100 will be described which is utilized to heat a process fluid. Electric heater 100 may include a housing 10. The electric heater 100 may include an inlet for a process fluid 12 and an outlet for the process fluid 14. The electric heater 100 may include an inlet for a working fluid 16 and an outlet for the working fluid 18. The electric heater 100 may include at least one electrical heating element 20 configured to transfer heat to the working fluid within the housing 10. Although specific components are shown in FIG. 1 as being included in electric heater 100, electric heater 100 may include more or fewer components. For example, electric heater 100 may include a plurality of electrical heating elements 20. Electric heater 100 may also integrate or separate various components shown in FIG. 1. The electric heater 100 may be part of, or integrated into, any system which require the heating of a process fluid, as described in more detail herein.

[0037] As shown in FIG. 1, housing 10 may further comprise at least one conduit 22, the conduit 22 fluidly connected to the inlet for the process fluid 12 and the outlet for the process fluid 14. As described in more detail herein, housing 10 may comprise a plurality of conduits 22, each conduit fluidically connected an inlet for the process fluid and to an outlet for the process fluid. Each conduit 22 may be, but is not limited to, a vertical conduit, a horizontal conduit, a serpentine conduit, a helical conduit, a U- conduit, an arbor conduit, an I conduit, a double I conduit, a W conduit, an L conduit, and any combination thereof. Each conduit 22 may be a bare conduit, an extended surface conduit, and any combination thereof. In some embodiments, conduit 22 may be configured to enhance heat transfer between the process fluid and the working fluid. For example, conduit 22 may include one or more internal layers or external layers or coatings of known heat transfer materials, including, but not limited to high flux coatings, internals to increase turbulence and like.

[0038] Still referring to FIG. 1, the housing 10 may be made of metal, refractory, ceramic, or a combination thereof. The housing 10 may be configured to prevent heat loss. For example, housing 10 may include one or more internal layers or external layers to further prevent heat loss. In some embodiments, housing 10 may include one or more internal or external layers of known insulating materials, including, but not limited to, refractory, fiberglass, mineral wool, cellulose, polymeric foams or panels, and combinations thereof.

[0039] The at least one electrical heating element 20 may be disposed of in any suitable manner within housing 10. For example, electrical heating element 20 may be disposed along the walls, ceiling, and / or floor of the housing 10. The at least one electrical heating element 20 may be suspended within the enclosure. The electrical heating element 20 may be, but is not limited to, a wire, a coil, a cartridge, a tube, a panel, and combinations thereof. The electrical heating element 20 may be a metal, an alloy, a semiconductor, a ceramic, and combinations thereof. In some embodiments, electric heating element 20 may be configured to enhance heat transfer between the heating element and the working fluid. For example, electrical heating element 20 may include one or more layers, coatings, or sheaths, the one or more layers, coatings, or sheaths may be of known materials to: enhance heat transfer including, but not limited to, high flux coatings, protect the electrical heating element 20 from corrosion, and so forth. The electrical heating element 20 may be a bare surface, an extended surface, and combinations thereof.

[0040] The electric heater 100 of FIG. 1 may be used in a method for heating a process fluid. In this embodiment, a working fluid 50 may be passed into the inlet for the working fluid 16 of housing 10. An electric current (not shown) may be passed to electrical heating element 20 to heat the working fluid 50 within the housing 10 to provide a heated working fluid 52. A process fluid 54 may be passed into the inlet for the process fluid 12 of housing 10. The process fluid 54 may be heated with the heated working fluid 52 to provide a heated process fluid 56 and a cooled working fluid 58.

[0041] The working fluid 50 may be any fluid that transfers heat. In some embodiments, the working fluid 50 is selected from a group consisting of air, steam, carbon dioxide, sulfur dioxide, other gaseous, inert or polar molecules, and any combination thereof. In some embodiments, one or more additives may be added to the working fluid 50 to enhance heat transfer including, but not limited to, helium, argon and xenon. In some embodiments, working fluid 50 may be in the gaseous or vapor state. The process fluid 54 is any fluid which a user of electric heater 100 desires to be heated.

[0042] Without being bound by theory, it is believed that the process fluid 54 is heated by both convective heat transfer and radiative heat transfer. The process fluid 54 is primarily heated through convective heat transfer from the heated working fluid 52. By “primarily” it is meant at least at least 60%, at least 90%, or at least 95% of the heat transfer is through convective heat transfer. The process fluid 54 is also slightly heated by radiative heat transfer from the at least one electrical heating element 20 and molecular radiation of the heated working fluid 52. By “slightly” it is meant less than 40%, less than 10%, or less than 5% of the heat transfer is through radiative heat transfer.

[0043] Turning now to FIG. 2, an exemplary system 2000 is shown. As described herein, electric heaters of the present invention may be part of, or integrated into, any system which requires the heating of a process fluid, including system 2000. As shown in FIG. 2, system 2000 may include electric heater 200 for heating a process fluid. While FIG. 2 shows one electric heater 200, the number of electric heaters 200 is not limited. The system 2000 may a plurality of electric heaters 200. In this embodiment, the plurality of electric heaters 200 may be arranged in series or in parallel.

[0044] In some embodiments, electric heater 200 may be of the type as described herein. Electric heater 200 may include a housing 210, an inlet for a process fluid (not shown), an outlet for the process fluid (not shown), an inlet for a working fluid (not shown), and an outlet for the working fluid (not shown). Electric heater 200 may include electrical heating elements 220 configured to heat the working fluid within housing 210. While FIG. 2 shows two electrical heating elements 220, the number of electrical heating elements is not limited. In some embodiments, housing 210 may further include at least one conduit (not shown), the at least one conduit fluidly connected to the inlet for the process fluid and the outlet for the process fluid.

[0045] System 2000 may further include at least one recirculation loop 230. The recirculation loop 230 may include at least one conduit (not shown) fluidly connected to the inlet for the working fluid and the outlet for the working fluid. The recirculation loop 230 may further comprise one or more additional elements, including a heater, a fan, a blower, a turbine, a compressor, a pump, and any combination thereof. These additional elements may be used to treat the working fluid as it is passed through recirculation loop 230. As shown in the specific example of FIG. 2, the recirculation loop 230 includes a heater 222 and a compressor 224 as the additional element. FIG. 2 shows the specific example where the additional element 224 is a compressor, as discussed above, other additional elements may be in recirculation loop 230. Further, while FIG. 2 shows that the compressor 224 is upstream of heater 222, the reverse order is contemplated. The recirculation loop 230 may be a negative pressure loop or a positive pressure loop.

[0046] Still referring to FIG. 2, the system 2000 may be used to heat a process fluid. In this embodiment, a working fluid 250 may be passed into the inlet for the working fluid of housing 210. An electric current (not shown) may be passed to heating elements 220 to heat the working fluid 250 within the housing 210 to provide a heated working fluid (not shown). A process fluid 254 may be passed into the inlet for the process fluid of housing 210. The process fluid 254 may be heated with the heated working fluid to provide a heated process fluid 256 and a cooled working fluid 258.

[0047] The cooled working fluid 258 may enter the recirculation loop 230 to be recirculated to the inlet for the working fluid in electric heater 200. In this way, cooled working fluid 258 may be recycled in system 2000 to heat a process fluid. Cooled working fluid 258 may be passed to optional cooler or heat sink 226 to further cool the cooled working fluid 258. In the recirculation loop 230, cooled working fluid 258 may be passed to compressor 224 to provide a compressed cooled working fluid 260. The compressed cooled working fluid 260 may be passed to heater 222 to provide heated compressed working fluid 262. Heated compressed working fluid 262 is returned to electric heater 200 via recirculation loop 230 as the working fluid 250.

[0048] Turning now to FIG. 3, an exemplary system 3000 for heating a process fluid is shown. As described herein, electric heaters of the present invention may be part of, or integrated into, any system which requires the heating of a process fluid, including system 3000. As shown in FIG. 3, system 3000 may include electric heater 300 for heating a process fluid. In some embodiments, electric heater 300 may be of the type as described herein. System 3000 may further include at least one recirculation loop 330. The recirculation loop 330 may be of the type as described herein. As shown in the specific example of FIG. 3, the recirculation loop 330 includes a heater 322 and a fan 326.

[0049] As shown in FIG. 3, system 3000 further includes fired heater 370 which is fluidly connected to electric heater 300. By “fired heater” what is meant is a heater which combusts fuel to produce heat. The fired heater 370 may be arranged in series or in parallel with the electric heater 300. In some embodiments, electric heater 300 may preheat a process fluid to be further heated by fired heater 370. In other embodiments, electric heater 300 may serve as a back-up heater when fired heater 370 is being cleaned, being repaired, and so forth.

[0050] The system 3000 may be used to heat a process fluid 354 using an electric heater 300 and a fired heater 370. In this embodiment, a working fluid 350 may be passed into electric heater 300. An electric current (not shown) may be passed to electrical heating element 320 to heat the working fluid 350 to provide a heated working fluid (not shown). In this embodiment, process fluid 354 is passed to fired heater 370 to provide preheated process fluid 380 heated to a first temperature T1. Preheated process fluid 380 may be passed into electric heater 300. The preheated process fluid 380 may be further heated with the heated working fluid within electric heater 300 to provide a heated process fluid 356 at a second temperature T2 and a cooled working fluid 358. Heated process fluid 356 may be recycled back to fired heater 370 to provide a heated process fluid 382 at a third temperature T3. Alternatively, heated process fluid 356 may exit system 3000 at temperature T2 as heated process fluid 384.

[0051] Still referring to FIG. 3, the cooled working fluid 358 may enter recirculation loop 330 to be recirculated to the inlet for the working fluid in electric heater 300. In this way, cooled working fluid 358 may be recycled in system 3000 to heat a process fluid. In the recirculation loop 330, cooled working fluid 358 may be passed to heater 322 to provide heated working fluid 364. Heated working fluid 364 may be passed to fan 326 to provide fanned heated working fluid 366. Fanned heated working fluid 366 is returned to electric heater 300 via recirculation loop 330 as the working fluid 350. The heater 322 may alternatively be placed downstream of fan 326.

[0052] Turning now to FIG. 4, an exemplary electric heater 400 will be described which is utilized to heat a process fluid. Electric heater 400 may include a housing 410. Electric heater 400 may include a plurality of inlets for a process fluid 412 and a plurality of outlets for the process fluid 414. The electric heater 400 may include an inlet for a working fluid 416 and an outlet for the working fluid 418. The electric heater 400 may include a plurality of electrical heating elements 420 configured to transfer heat to the working fluid within the housing 410. Housing 410 may further comprise a plurality of conduits 422. The conduits 422 may be fluidly connected to the plurality of inlets for a process fluid 412 and the plurality of outlets for the process fluid 414.

[0053] The electric heater 400 of FIG. 4 may be used in a method for heating a process fluid. In this embodiment, a working fluid 450 may be passed into the inlet for the working fluid 416 of housing 410. An electric current (not shown) may be passed to electrical heating elements 420 to heat the working fluid 450 within the housing 410 to provide a heated working fluid 452. A process fluid 454 may be passed into the plurality of inlets for a process fluid 412 of housing 410. The process fluid 454 may be heated with the heated working fluid 452 to provide a heated process fluid 456 and a cooled working fluid 458. In the specific embodiment shown in FIG. 4, the process fluid 454 flows counter currently to heated working fluid 452, however although not depicted as such, the process fluid 454 may be co-current flow or cross flow. Without being bound by theory, it is believed that having the process fluid 454 flow counter currently to heated process fluid 456 increases the heat transfer between process fluid 454 and heated working fluid 452.

[0054] Turning now to FIG. 5, an exemplary system 5000 for heating a process fluid is shown. As shown in FIG. 5, system 5000 may include electric heater 500 for heating a process fluid. In some embodiments, electric heater 500 may be of the type as described herein. Electric heater 500 may include a housing 510 and a plurality of electrical heating elements 520. System 5000 may further include at least one recirculation loop 530. The recirculation loop 530 may be of the type as described herein. As shown in the specific example of FIG. 5, recirculation loop 530 includes a heater 522, a compressor 524 as the additional element, and a filter 528.

[0055] The system 5000 may be used to heat a process fluid 554 using electric heater 500. In this specific example, a working fluid 550 is introduced into housing 510. Working fluid 550 flows through housing 510, and in doing so, flows past a plurality of electrical heating elements 520, providing a heated working fluid. At the same time, process fluid 554 is introduced and flows through into housing 510 counter currently to the heated working fluid. While FIG. 5, shows process fluid 554 moving counter currently to heated working fluid, as mentioned above, co-current flow or cross flow is also contemplated. As described in more detail herein, as process fluid 554 passes the heated working fluid counter currently, the heat transfers from heated working fluid to process fluid 554 to provide a heated process fluid 556 and a cooled working fluid 558.

[0056] As shown in FIG. 5, a working fluid 550 may enter housing 510 of electric heater 500. Initially, working fluid 550 may have an initial temperature T1 of 598.2 ºF (314.56 ºC) at point (A). As the working fluid 550 flows past electrical heating element 520 it is heated to at temperature T2 to provide a first heated working fluid at point (B), which may be 1150 ºF (621.11 ºC). When the first heated working fluid flows past process fluid 554, which is flowing counter currently in a conduit (not shown) through housing 510, at least some heat is transferred from first heated working fluid to process fluid, providing a first cooled working fluid and a heated process fluid. At point (C), first cooled working fluid may have a temperature T3 of 677.6 ºF (358.67 ºC). As first cooled working fluid flows past another electrical heating element 520 it is reheated to temperature T2 at point (D) to provide a second heated working fluid. When the second heated working fluid flows past slightly heated process fluid, at least some heat is transferred from second heated working fluid to heated process fluid, providing a second cooled working fluid and a further heated process fluid. At point (E), the second cooled working fluid may have a temperature T4 of 684 ºF (362.22 ºC). As second cooled working fluid flows past another electrical heating element 520 it is reheated to temperature T2 at point (F) to provide a third heated working fluid. When the third heated working fluid flows past further heated process fluid, at least some heat is transferred from third heated working fluid to process fluid 554, providing a third cooled working fluid and a further heated process fluid. At point (G), the second cooled working fluid may have a temperature T4 of 670.50 ºF (354.72 ºC). As third cooled working fluid flows past another electrical heating element 520 it is reheated to temperature T2 at point (H) to provide a fourth heated working fluid. When the fourth heated working fluid flows past further heated process fluid, at least some heat is transferred from fourth heated working fluid to further heated process fluid, providing a fourth cooled working fluid and heated process fluid 556. At point (I), the fourth cooled working fluid may have a temperature T5 of 598.20 ºF (314.56 ºC). The temperature values in this example are for illustrative purposes only and are not intended to be limiting.

[0057] Still referring to FIG. 5, fourth cooled working fluid may exit housing 510 as a cooled working fluid 558 and enter recirculation loop 530. Recirculation loop 530 may treat or process cooled working fluid 558 to be reused as working fluid 550, to be vented to the atmosphere, or a combination thereof. In some embodiments, at least a portion of the cooled working fluid 558 may be passed to filter or scrubber 528 to provide a cleaned working fluid 568, which may be vented to the atmosphere. The remainder of cooled working fluid 558 may be passed to compressor 524 to provide compressed cooled working fluid 560. The compressed cooled working fluid 560 may be passed to heater 522 to provide heated compressed working fluid 562. Heated compressed working fluid 562 may enter electric heater 500 as working fluid 550. In some embodiments, recirculation loop 530 may include working fluid feed 570 to supplement working fluid 550 as necessary.

[0058] As shown in FIG. 5, in this embodiment, process fluid 554 enters housing 510 at point (J) at a temperature T0. In this example, temperature T0 may be 512.90 ºF (267.17 ºC). As process fluid 554 flows counter currently to working fluid 550 throughout housing 510 of, it is continuously and incrementally heated to provide heated process fluid 556. Heated process fluid 556 may leave electric heater 200 and have a temperature of 565 ºF (296.11 ºC) at point (K). The temperature values in this example are for illustrative purposes only and are not intended to be limiting.

[0059] The systems described herein may include a controller or a computing device comprising a processing and a memory which has stored therein computer-executable instructions for implementing the processes described herein. The processing unit may comprise any suitable devices configured to cause a series of steps to be performed so as to implement the method such that instructions, when executed by the computing device or other programmable apparatus, may cause the functions / acts / steps specified in the methods described herein to be executed. The processing unit may comprise, for example, any type of general-purpose microprocessor or microcontroller, a digital signal processing (DSP) processor, a central processing unit (CPU), an integrated circuit, a field programmable gate array (FPGA), a reconfigurable processor, other suitably programmed or programmable logic circuits, or any combination.

[0060] The memory may be any suitable known or other machine-readable storage medium. The memory may comprise non-transitory computer readable storage medium such as, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. The memory may include a suitable combination of any type of computer memory that is located either internally or externally to the device such as, for example, random-access memory (RAM), read-only memory (ROM), compact disc read-only memory (CDROM), electro-optical memory, magneto-optical memory, erasable programmable read-only memory (EPROM), and electrically-erasable programmable read-only memory (EEPROM), Ferroelectric RAM (FRAM) or the like. The memory may comprise any storage means (e.g., devices) suitable for retrievably storing the computer-executable instructions executable by processing unit.

[0061] Computer-executable instructions may be in many forms, including modules, executed by one or more computers or other devices. Generally, modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. Typically, the functionality of the modules may be combined or distributed as desired in various embodiments.

[0062] It will be appreciated that the systems and devices and components thereof may utilize communication through any of various network protocols such as TCP / IP, Ethernet, FTP, HTTP and the like, and / or through various wireless communication technologies such as GSM, CDMA, Wi-Fi, and WiMAX, is and the various computing devices described herein may be configured to communicate using any of these network protocols or technologies.

[0063] Any of the above lines, conduits, units, devices, vessels, surrounding environments, zones or similar may be equipped with one or more monitoring components including sensors, measurement devices, data capture devices or data transmission devices. Signals, process or status measurements, and data from monitoring components may be utilized to monitor conditions in, around, and on process equipment. Signals, measurements, and / or data generated or recorded by monitoring components may be collected, processed, and / or transmitted through one or more networks or connections that may be private or public, general or specific, direct or indirect, wired or wireless, encrypted or not encrypted, and / or combination(s) thereof; the specification is not intended to be limiting in this respect.

[0064] Signals, measurements, and / or data generated or recorded by monitoring components may be transmitted to one or more computing devices or systems. Computing devices or systems may include at least one processor and memory storing computer-readable instructions that, when executed by the at least one processor, cause the one or more computing devices to perform a process that may include one or more steps.

[0065] For example, the one or more computing devices may be configured to receive, from one or more monitoring component, data related to at least one piece of equipment associated with the process. The one or more computing devices or systems may be configured to analyze the data. Based on analyzing the data, the one or more computing devices or systems may be configured to determine one or more recommended adjustments to one or more parameters of one or more processes described herein. The one or more computing devices or systems may be configured to transmit encrypted or unencrypted data that includes the one or more recommended adjustments to the one or more parameters of the one or more processes described herein.

[0066] It should be appreciated and understood by those of ordinary skill in the art that various other components such as valves, pumps, filters, coolers, etc. were not shown in the drawings as it is believed that the specifics of same are well within the knowledge of those of ordinary skill in the art and a description of same is not necessary for practicing or understanding the embodiments of the present invention.Experiments

[0067] The composition of the working fluid, and its control, may impact heat transfer. FIGS. 6 and 7 shows increasing the concentration of polar molecules in the working fluid can result in increased shock / radiative and total heat transfer of the working fluid respectively. Polar molecules increase radiant heat transfer. Thus, working fluids having or comprising polar molecules (e.g., water), will have increased radiant heat transfer between electrical heating elements and the working fluid. Thus, working fluids having or comprising polar molecules increase the heat-carrying capacity of the working fluid, and an increased heat transfer may be achieved from the same surface area at the same circulation rate.

[0068] The mass velocity modulation of the working fluid can also enhance heat transfer of the working fluid. FIG. 8 shows a co-relation of how increasing the mass velocity of working fluid can increase heat transfer, even while inlet temperature and process coil surface area remain the same.Specific Embodiments

[0069] While the following is described in conjunction with specific embodiments, it will be understood that this description is intended to illustrate and not limit the scope of the preceding description and the appended claims.

[0070] A first embodiment of the invention is an electric heater for heating a process fluid, the electric heater comprising a housing, an inlet for a process fluid and an outlet for the process fluid, an inlet for a working fluid and an outlet for the working fluid, and at least one electrical heating element configured to transfer heat to the working fluid within the housing. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, the housing further comprising at least one conduit, the at least one conduit fluidly connected to the inlet for the process fluid and the outlet for the process fluid. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, further comprising a plurality of conduits, each conduit fluidically connected to the inlet for the process fluid and the outlet for the process fluid. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, wherein each conduit is selected from a group consisting of bare conduit, extended surface conduit, vertical conduit, horizontal conduit, serpentine conduit, helical conduit, U- conduit, arbor conduit, I conduit, double I conduit, W conduit, L conduit, and any combination thereof. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, further comprising a plurality of electrical heating elements. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, wherein the working fluid is selected from a group consisting of air, steam, carbon dioxide, sulfur dioxide, other gaseous, inert or polar molecules, and any combination thereof.

[0071] A second embodiment of the invention is a system, the system comprising a system for heating a process fluid, the system including a housing, an inlet for a process fluid and an outlet for the process fluid, an inlet for a working fluid and an outlet for the working fluid, and at least one electrical heating element configured to transfer heat to the working fluid within the housing; and at least one recirculation loop, the at least one recirculation loop including at least one conduit, the at least one conduit fluidly connected to the inlet for the working fluid and the outlet for the working fluid. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, the at least one recirculation loop further comprising at least one heater, the at least one heater configured to heat the working fluid in the at least one recirculation loop. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, the at least one recirculation loop further comprising at least one element from a group consisting of a fan, a blower, a turbine, a compressor, a pump, and any combination thereof. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, wherein the at least one recirculation loop comprises a negative pressure loop. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, further comprising at least one fired heater configured to heat the process fluid. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, wherein the at least one fired heater is arranged in series with the system. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, wherein the at least one fired heater is arranged in parallel with the system. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, further comprising a second system for heating the process fluid, the second heater including a housing, an inlet for the process fluid and an outlet for the process fluid, an inlet for the working fluid and an outlet for the working fluid, and at least one electrical heating element configured to transfer heat to the working fluid within the housing. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, wherein the system and the second system are arranged in series. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, wherein the system and the second system are arranged in parallel.

[0072] A third embodiment of the invention is a method of heating a process fluid, the method comprising passing a working fluid into an inlet for a working fluid in a housing of an electrical heater, the housing including a first electrical heating element; passing an electric current into the first electrical heating element to heat the working fluid within the electrical heater to provide a heated working fluid; passing a process fluid into an inlet for a process of the electrical heater; and heating the process fluid within the electrical heater with the heated working fluid to provide a heated process fluid and a cooled working fluid. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the third embodiment in this paragraph, the method further comprising passing the cooled working fluid to at least one recirculation loop, the at least one recirculation loop including at least one conduit, the at least one conduit fluidly connected to an outlet for the working fluid of the system and the working fluid inlet; and passing the cooled working fluid to the inlet for the working fluid using the at least one conduit. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the third embodiment in this paragraph, the at least one recirculation loop further comprising at least one heater, the method further comprising heating the cooled working fluid using the at least one heater to provide a preheated working fluid; and passing the preheated working fluid to the inlet for the working fluid using the at least one conduit. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the third embodiment in this paragraph, further comprising passing an electric current into a second electrical heating element to reheat the working fluid within the electrical heater to provide a reheated working fluid; and heating the process fluid within the electrical heater with the reheated working fluid.

[0073] Without further elaboration, it is believed that using the preceding description that one skilled in the art can utilize the present invention to its fullest extent and easily ascertain the essential characteristics of this invention, without departing from the spirit and scope thereof, to make various changes and modifications of the invention and to adapt it to various usages and conditions. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limiting the remainder of the disclosure in any way whatsoever, and that it is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0074] In the foregoing, all temperatures are set forth in degrees Celsius and, all parts and percentages are by weight, unless otherwise indicated.

[0075] While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.

Examples

specific embodiments

[0069]While the following is described in conjunction with specific embodiments, it will be understood that this description is intended to illustrate and not limit the scope of the preceding description and the appended claims.

[0070]A first embodiment of the invention is an electric heater for heating a process fluid, the electric heater comprising a housing, an inlet for a process fluid and an outlet for the process fluid, an inlet for a working fluid and an outlet for the working fluid, and at least one electrical heating element configured to transfer heat to the working fluid within the housing. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, the housing further comprising at least one conduit, the at least one conduit fluidly connected to the inlet for the process fluid and the outlet for the process fluid. An embodiment of the invention is one, any or all of prior embodiments in this p...

Claims

1. An electric heater for heating a process fluid, the electric heater comprising:a housing,an inlet for a process fluid and an outlet for the process fluid,an inlet for a working fluid and an outlet for the working fluid, andat least one electrical heating element configured to transfer heat to the working fluid within the housing.

2. The electric heater of claim 1, the housing further comprising at least one conduit, the at least one conduit fluidly connected to the inlet for the process fluid and the outlet for the process fluid.

3. The electric heater of claim 2, further comprising a plurality of conduits, each conduit fluidically connected to the inlet for the process fluid and the outlet for the process fluid.

4. The electric heater of claim 3, wherein each conduit is selected from a group consisting of: bare conduit, extended surface conduit, vertical conduit, horizontal conduit, serpentine conduit, helical conduit, U- conduit, arbor conduit, I conduit, double I conduit, W conduit, L conduit, and any combination thereof.

5. The electric heater of claim 1, further comprising a plurality of electrical heating elements.

6. The electric heater of claim 1, wherein the working fluid is selected from a group consisting of: air, steam, carbon dioxide, sulfur dioxide, other gaseous, inert or polar molecules, and any combination thereof.

7. A system, the system comprising:an electric heater for heating a process fluid, the electric heater including:a housing,an inlet for a process fluid and an outlet for the process fluid,an inlet for a working fluid and an outlet for the working fluid, andat least one electrical heating element configured to transfer heat to the working fluid within the housing; andat least one recirculation loop, the at least one recirculation loop including:at least one conduit, the at least one conduit fluidly connected to the inlet for the working fluid and the outlet for the working fluid.

8. The system of claim 7, the at least one recirculation loop further comprising at least one heater, the at least one heater configured to heat the working fluid in the at least one recirculation loop.

9. The system of claim 7, the at least one recirculation loop further comprising at least one element from a group consisting of a fan, a blower, a turbine, a compressor, a pump, and any combination thereof.

10. The system of claim 7, wherein the at least one recirculation loop comprises a negative pressure loop.

11. The system of claim 7, further comprising at least one fired heater configured to heat the process fluid.

12. The system of claim 11, wherein the at least one fired heater is arranged in series with the electric heater.

13. The system of claim 11, wherein the at least one fired heater is arranged in parallel with the electric heater.

14. The system of claim 7, further comprising a second electric heater for heating the process fluid, the second heater including a housing, an inlet for the process fluid and an outlet for the process fluid, an inlet for the working fluid and an outlet for the working fluid, and at least one electrical heating element configured to transfer heat to the working fluid within the housing.

15. The system of claim 14, wherein the electric heater and the second electric heater are arranged in series.

16. The system of claim 14, wherein the electric heater and the second electric heater are arranged in parallel.

17. A method of heating a process fluid, the method comprising:passing a working fluid into an inlet for a working fluid in a housing of an electrical heater, the housing including a first electrical heating element;passing an electric current into the first electrical heating element to heat the working fluid within the electrical heater to provide a heated working fluid;passing a process fluid into an inlet for a process of the electrical heater; andheating the process fluid within the electrical heater with the heated working fluid to provide a heated process fluid and a cooled working fluid.

18. The method of claim 17, the method further comprising:passing the cooled working fluid to at least one recirculation loop, the at least one recirculation loop including at least one conduit, the at least one conduit fluidly connected to an outlet for the working fluid of the electric heater and the working fluid inlet; andpassing the cooled working fluid to the inlet for the working fluid using the at least one conduit.

19. The method of claim 18, the at least one recirculation loop further comprising at least one heater, the method further comprising:heating the cooled working fluid using the at least one heater to provide a preheated working fluid; andpassing the preheated working fluid to the inlet for the working fluid using the at least one conduit.

20. The method of claim 17, further comprising:passing an electric current into a second electrical heating element to reheat the working fluid within the electrical heater to provide a reheated working fluid; andheating the process fluid within the electrical heater with the reheated working fluid.

Images