High-power electric heater

Abstract

An electric heater comprising a core and a primary winding positioned adjacent to the core and capable of operating at power levels exceeding 1 MW to generate a flow of primary current. A first flow member extends around a first portion of the core and defines an inlet, and a second flow member extends around a second portion of the core and defines an outlet. A third flow member is positioned adjacent to the first surface and connected to the first and second flow members to complete a continuous flow path between the inlet and outlet. The first, second, and third flow members cooperate to define a portion of the secondary winding. A flowing fluid is supplied to the inlet and collected from the outlet, and the flowing fluid is heated in accordance with the secondary current that flows through the secondary winding, induced by the flowing primary current.

Description

Background Art

[0001] Many industrial processes and other processes require high-temperature heat. This heat is often provided using water or other fluids heated by a combustion process such as a boiler, furnace, or other heating device. Often, these heating devices are fueled using fossil fuels such as coal, oil, or natural gas.

[0002] From an environmental perspective, alternative heat sources in the form of generally hot water, steam, or other fluids that can provide the necessary level of heat without using fossil fuels should be desirable. On the other hand, conventional electric heating means currently available cannot be scaled up to the high power levels required by most industrial processes.

Summary of the Invention

[0003] An electric heater according to one aspect includes a core oriented to define a first surface and a second surface opposite the first surface. A primary winding is disposed around the core and is operable at a power level exceeding 1 MW to generate a flow of primary current. A first flow member extends around a first portion of the core to define an inlet, and a second flow member extends around a second portion of the core to define an outlet, the second portion being different from the first portion. A third flow member is disposed adjacent to the first surface and is connected to the first and second flow members to complete a continuous flow path for a process fluid between the inlet and the outlet. The first, second, and third flow members cooperate to define a portion of a secondary winding. The secondary winding is completed (closed) by a power transfer connection component between the first and second flow members. The flowing fluid is sent to the inlet and collected from the outlet, and the flowing fluid is heated in response to a secondary current flowing in the secondary winding induced by the flow of the primary current.

[0004] An electric heater according to another embodiment includes a core oriented to define a first surface and a second surface opposite the first surface. A primary winding is positioned between the core surfaces and is operable at power levels exceeding 1 MW to generate a flow of primary current. A first flow member extends around a first portion of the core to define an inlet, and a second flow member extends around a second portion of the core to define an outlet, the second portion being distinct from the first portion. A third flow member is positioned adjacent to the first surface and connected to the first and second flow members to complete a continuous flow path for process fluid between the inlet and the outlet. The first, second, and third flow members cooperate to define a portion of a secondary winding. The secondary winding is completed (closed) by a power transmission connection between the first and second flow members. The flowing fluid is delivered to the inlet and collected from the outlet. This flowing fluid is heated in response to a secondary current flowing through the secondary winding, which is induced by the flow of the primary current.

[0005] This electric heater includes, for example, a core having a plurality of laminates stacked in a first direction, in which case each laminate is formed from a magnetic material.

[0006] This electric heater includes, for example, a core in which a magnetic material is wound from a continuous strip of magnetic material.

[0007] This electric heater operates at power levels ranging from, for example, 1 MW to 1000 MW.

[0008] This electric heater includes, for example, a third flow member having a first pipe organized along a meandering path extending between a first flow member and a second flow member.

[0009] This electric heater includes, for example, a plurality of tubes and a plurality of end caps. In this case, each of the plurality of tubes is straight, and the plurality of tubes and the plurality of end caps work together to define a meandering path extending between a first flow member and a second flow member.

[0010] To distribute the fluid flow most uniformly, the multiple tubes of the third flow member can maintain a state where each tube is completely isolated. This can be combined with the first and second flow members, which consist of individual larger diameter tubes connected to the multiple individual tubes of the third flow member via connecting parts.

[0011] This electric heater includes, for example, an inlet manifold and an outlet manifold, in which the inlet of the first flow member is connected to the inlet manifold and the outlet of the second flow member is connected to the outlet manifold.

[0012] This electric heater includes, for example, a third flow member that can be removed from the first flow member and the second flow member without disassembling the core and primary winding.

[0013] The electric heater includes, for example, a core defining three core bars and two core apertures, in which the primary winding includes a first phase winding extending around a first core bar, a second phase winding extending around a second core bar, and a third phase winding extending around a third core bar, and the secondary winding includes a first continuous flow path extending around a first core bar, a second continuous flow path extending around a second core bar, and a third continuous flow path extending around a third core bar.

[0014] This electric heater includes, for example, first, second, and third phase primary windings surrounded by first, second, and third cores.

[0015] This electric heater is configured, for example, using a single-phase or two-phase power distribution system. The two-phase system can be operated as a three-phase system.

[0016] This electric heater includes, for example, a first surface which is the upper surface and a second surface which is the lower surface, and in this case the first direction extends between the lower surface and the upper surface and is the vertical direction.

[0017] This electric heater includes, for example, a first surface which is the right surface and a second surface which is the left surface, and in this case the first direction extends between the right surface and the left surface and is the left-right (lateral) direction.

[0018] This electric heater includes, for example, a first flow member which is one of a plurality of first flow members, each first flow member which includes an inlet connected to an inlet manifold. In this case, the second flow member is one of a plurality of second flow members, each second flow member which includes an outlet connected to an outlet manifold.

[0019] The electric heater includes, for example, a third flow member which is one of a plurality of third flow members, each third flow member being connected to a corresponding one of the first flow members and a corresponding one of the second flow members to define one of a plurality of continuous flow paths, each of which is fluidically isolated from the other continuous flow paths between them, except for an inlet manifold and an outlet manifold. Other technical features will be apparent to those ordinary in the art from the drawings, description and claims shown below.

[0020] At least the single-phase primary winding, core, and secondary winding are installed adjacent to each other, provided that the connection between these items is purely magnetic. This has the advantage that the high-temperature secondary winding is not physically connected to other parts of the electric heater, allowing them to operate at lower temperatures, thus avoiding high stress and enabling long-life performance.

[0021] A method for heating a flowing fluid according to another embodiment includes providing a primary winding in a core, arranging a secondary winding around the core, the secondary winding defining a continuous flow path between an inlet and an outlet, such that the flowing fluid passes from the inlet through the continuous flow path to the outlet. The method further includes allowing a primary current to flow through the primary winding, the primary current having a primary voltage that yields a power level of at least 1 MW. The method further includes inducing a secondary current flow in the secondary winding in response to the primary current flow, heating the secondary winding in response to the secondary current flow, and heating the flowing fluid in response to the heating of the secondary winding.

[0022] The method for heating a flowing fluid further includes stacking multiple laminates in a first direction, in which case each laminate is formed from a magnetic material.

[0023] This method for heating a flowing fluid includes, for example, operating at power levels of 1 MW to 1000 MW.

[0024] The method for heating a flowing fluid includes, for example, a third flow member comprising a first pipe arranged along a meandering path extending between a first flow member and a second flow member.

[0025] The method for heating a flowing fluid further includes a plurality of tubes and a plurality of end caps, each tube being linear. The method further includes connecting a first quarter of the plurality of tubes to a first flow member and a first end cap, connecting a second quarter of the plurality of tubes to a first end cap and a second end cap, connecting a third quarter of the plurality of tubes to a second end cap and a third end cap, and connecting a fourth quarter of the plurality of tubes to a third end cap and a second flow member, wherein the plurality of tubes and the plurality of end caps cooperate to define a meandering path between the first flow member and the second flow member.

[0026] This method of heating a flowing fluid includes, for example, a first flow member that is one of a plurality of first flow members, a second flow member that is one of a plurality of second flow members, each first flow member includes an inlet, and each second flow member includes an outlet. This method further includes connecting each inlet of the first flow members to an inlet manifold respectively, and connecting each outlet of the second flow members to an outlet manifold.

[0027] This method of heating a flowing fluid further includes removing a third flow member from the first flow member and the second flow member without disassembling the core and the primary winding.

[0028] This method of heating a flowing fluid includes, for example, using a core that defines three core bars and two core apertures, in which case the primary winding includes a first phase winding, a second phase winding, and a third phase winding, and the secondary winding includes a first continuous flow path, a second continuous flow path, and a third continuous flow path. This method further includes stretching the first phase winding around the first core bar, stretching the second phase winding around the second core bar, stretching the third phase winding around the third core bar, stretching the first continuous flow path around the first core bar, stretching the second continuous flow path around the second core bar, and stretching the third continuous flow path around the third core bar.

[0029] This method of heating a flowing fluid includes, for example, a third flow member that is one of a plurality of third flow members. This method further includes connecting each third flow member to a corresponding one of the first flow members and a corresponding one of the second flow members to define one of a plurality of continuous flow paths, and each of the continuous flow paths is fluidly isolated from other continuous flow paths between them, excluding the inlet manifold and the outlet manifold. Other technical features will be apparent to those of ordinary skill in the art from the drawings, description, and claims shown later.

Brief Description of the Drawings

[0030] To facilitate the review of specific elements or processes, the leading digit in the reference numbers refers to the figure number in which the corresponding element was first introduced. [Figure 1] Perspective view of a high-power electric heater operable to heat a flowing fluid. [Figure 2] Perspective view of the core used in the electric heater of FIG. 1. [Figure 3] Cross-sectional view of the electric heater of FIG. 1. [Figure 4] Schematic view of the electric heater of FIG. 1. [Figure 5] [[ID=第十五]]Shows the configuration of a high-power electric heater operable to heat a flowing fluid. [Figure 6] Shows another configuration of a high-power electric heater having a toroidal core and operable to heat a flowing fluid. [Figure 7] Shows aspects of the subject matter according to one embodiment.

Mode for Carrying Out the Invention

[0031] In describing embodiments of the present invention in detail, it should be understood that the present invention is not limited to the details of the configurations / structures and the arrangements of components described in the detailed description or illustrated in the drawings with respect to its application. The present invention is capable of other embodiments and can be embodied and implemented in various ways. It should also be understood that the expressions and terms used herein are for the purpose of description and should not be construed as having a limiting meaning. Further, although multiple embodiments or configurations / structures may be described herein, features, methods, steps, components, etc. described with respect to one embodiment are equally applicable to other embodiments, unless otherwise stated.

[0032] Various techniques relating to the system and method are described below with reference to the drawings, where similar reference numerals represent similar elements throughout the drawings. The drawings discussed below and the various embodiments used to illustrate the principles of the disclosure herein are for illustrative purposes only and should not be construed as limiting the scope of the disclosure. Those with ordinary skill in the art will understand that the principles of the disclosure can be implemented in any well-organized apparatus. It should be understood that a function described as being performed by a particular system element may be performed by multiple elements. Similarly, for example, one element may be configured to perform a function described as being performed by multiple elements. Many of the innovative teachings of this application are described with reference to the non-limiting embodiments described herein.

[0033] While terms such as “first,” “second,” and “third” may be used herein to refer to various elements, information, functions, or processes, these elements, information, functions, or processes should not be limited by such terms. Rather, these numerical adjectives are used to distinguish different elements, information, functions, or processes from one another. For example, without departing from the scope of this disclosure, the first element, information, function, or process may also be called the second element, information, function, or process, and similarly, the second element, information, function, or process may also be called the first element, information, function, or process.

[0034] Furthermore, "adjacent to" can mean that one element is relatively close to another but not touching it, or that one element touches another part, unless the context clearly indicates otherwise. In addition, "based on" is used to mean "based, at least in part, on" unless other meanings are specifically stated. "About," "substantially," or similar terms are used to include variations in values ​​that are within normal manufacturing tolerances for the dimension in question. If industry standards are not available, a 20% variation falls within the scope of the term unless other meanings are specified.

[0035] Many industrial processes require heat, which is typically supplied in the form of hot water or steam, hot gas, oil, or other thermal fluids such as brine, molten salt, air, supercritical CO2, helium, hydrogen, hydrocarbons, molten metal, or particulate gas streams. To date, most of this heat has been supplied by boilers or furnaces that burn fossil fuels such as coal, oil, or natural gas to produce steam, or by directly heating other fluids. In many cases, the energy required to generate the necessary heat exceeds 1 MW, reaching hundreds of MW, or even 1000 MW.

[0036] Figure 1 illustrates an example of a high-power electric heater 100 capable of operating at an induction frequency of 30 to 400 Hz in the range of 1 to 1000 MW, preferably in the range of 10 to 100 MW, and providing heat to a given process. Naturally, other configurations can operate in different power ranges, including 10 to 1000 MW. The electric heater 100 includes a core 200, a primary winding 102, and a secondary winding 104. The core 200, shown in detail in Figure 2, includes a plurality of laminates 202 stacked in a stacking direction, i.e., a first direction 204. In the illustrated configuration, the first direction 204 extends from the bottom surface 206 of the core 200 to the top surface 208 of the core 200 and is vertical, but other orientations and configurations are also possible. Each of the laminates 202 has a predetermined shape and is formed from a magnetic material of a ferromagnetic material such as iron, electrical steel, or carbon steel.

[0037] While cores can be stacked in one direction, we propose a type of toroidal core that can be "stacked" inexpensively because it is wound. We also wish to assert our rights to ferrite or powder cores, as they may offer larger, lower-cost alternatives, albeit of lower quality.

[0038] In the illustrated configuration, each laminate 202 has a shape that, when stacked with other laminates 202, cooperates to define a first core bar 210, a second core bar 212, and a third core bar 214. A core aperture 216 is defined between adjacent core bars. This results in a core 200 suitable for use as a three-phase core. The laminate 202 can be formed as a single continuous component or as a plurality of components aligned to form a predetermined final laminate shape.

[0039] Returning to Figure 1, the primary winding 102 includes a first phase winding 106 arranged around the first core bar 210, a second phase winding 108 arranged around the second core bar 212, and a third phase winding 110 arranged around the third core bar 214. When operating with three-phase power, the first phase carries current through the first phase winding 106, the second phase through the second phase winding 108, and the third phase through the third phase winding 110. Different arrangements may be used in other configurations. For example, a single-phase power supply may include a single winding around a single core bar.

[0040] The secondary winding 104 includes a plurality of first continuous flow channels 112 arranged around the first core bar 210, a plurality of second continuous flow channels 114 arranged around the second core bar 212, and a plurality of third continuous flow channels 116 arranged around the third core bar 214.

[0041] Each of the first continuous flow channels 112, the second continuous flow channel 114, and the third continuous flow channel 116 includes a first flow member 118, a second flow member 120, and a third flow member 122, which are connected to the inlet manifold 124 and the outlet manifold 126. For each continuous flow channel, each of the first flow members 118 includes an inlet opening connected to the inlet manifold 124 and a second end opposite to the inlet opening. In the illustrated configuration, each of the first flow members 118 is oriented vertically, substantially straight, and perpendicular to the central axis of the inlet manifold 124. The first flow members 118 are arranged along the first sides of the core bars 210, 212, and 214, respectively.

[0042] In the illustrated configuration, the inlet manifold 124 is a cylindrical pipe / tube with one end closed and the other end defining an inlet 128. Each of the first flow members 118 for a particular phase is connected to the inlet manifold 124 for that particular phase along the outer wall of the inlet manifold 124. In other configurations, other shapes or configurations may be used for the inlet manifold 124 as needed.

[0043] For each continuous flow path, each of the second flow members 120 for a particular phase includes an outlet opening connected to the outlet manifold 126 for that particular phase, and a second end opposite to the outlet opening. In the illustrated configuration, each of the second flow members 120 is oriented vertically, substantially straight, and perpendicular to the central axis of the outlet manifold 126. The second flow members 120 are positioned along the second side of each of the core bars 210, 212, and 214 opposite to the first side.

[0044] In the illustrated configuration, the outlet manifold 126 is a cylindrical pipe / tube with one end closed and the opposite end defining an outlet 130. Each of the second flow members 120 connects to the outlet manifold 126 along its outer wall. In other configurations, other shapes or configurations of the outlet manifold 126 may be used as needed.

[0045] The structure shown in Figure 1 includes a first flow member 118 and a second flow member 120 arranged parallel to each other and in a straight orientation in the vertical direction, but other configurations are also possible.

[0046] For each continuous flow channel, each of the third flow members 122 includes a first end connected to the second end of the first flow member 118 and a second end connected to the second end of the second flow member 120. Thus, each set consisting of the first flow member 118, the second flow member 120, and the third flow member 122 completes a continuous flow channel extending between the inlet 128 and the outlet 130.

[0047] In another configuration, the first flow member 118 and the second flow member 120 are formed as a single member having one inlet 128 and one outlet 130. This single member is connected to the end of the third flow member 122 to form a continuous flow path. The inlet and outlet manifolds for fluid connection are moved to one of the connections between this single member and the flow member 122.

[0048] To provide the most uniform flow distribution in the multiple pipes of the third flow member, each pipe can be completely isolated from the others. Flows from or to various pipes can be merged using the first flow member 118 and / or second flow member 120, which include a single large-diameter pipe that receives or directs the flow to all of the multiple pipes.

[0049] As shown in Figure 3, each third flow member 122 includes one or more pipes / tubes 132 arranged in a meandering path 302 (also shown in Figure 4) extending between the first flow member 118 and the second flow member 120. In the configurations shown in Figures 3 and 4, each pipe 132 (only one is shown in Figure 4) follows a meandering path 302 that includes three 180-degree turns, although other numbers of turns (e.g., one, five, seven, etc.) are also possible. End caps 304 are placed at each of the 180-degree turns and act like manifolds, receiving the flow from a pipe 132 flowing in one direction and redirecting that flow to a pipe 132 flowing in the opposite direction. This configuration allows the use of straight pipes 132 rather than pipes 132 that actually have bends in the middle. However, configurations with both straight and curved pipes are also possible.

[0050] As is evident, other configurations of the pipe 132 and meandering path 302 may include different turns (e.g., 45 degrees, 90 degrees, etc.), fewer than three 180-degree turns, more than three 180-degree turns, or any combination thereof. Furthermore, curved pipes 132 can be used instead of straight pipes 132. The meandering path 302 can be of any given length and arrangement and will be evident to be selected to achieve a given level of current and heat conduction, as will be described in more detail below. In addition, the first flow member 118, the second flow member 120, and / or the third flow member 122 may be surrounded by insulating material (not shown) to guide the generated heat to the process fluid and improve thermal efficiency.

[0051] Returning to Figure 1, the primary winding 102, which includes a first phase winding 106, a second phase winding 108, and a third phase winding 110, comprises multiple primary coils, each extending around its respective core bar. Similarly, the secondary winding 104, which includes a first continuous flow channel 112, a second continuous flow channel 114, and a third continuous flow channel 116, comprises multiple first flow members 118, a second flow member 120, and a power connector 306, which work together to define a secondary coil in the form of a continuous flow channel. The number of primary coils and secondary coils are selected such that a predetermined current flows at a predetermined voltage in the primary winding 102 and simultaneously generates predetermined currents and voltages in the secondary winding 104.

[0052] For example, in one configuration, if the number of primary coils is significantly greater than the number of secondary coils, it results in a step-down transformer configuration. That is, the secondary voltage of the secondary winding 104 is significantly reduced compared to the primary voltage of the primary winding 102. Similarly, the secondary current in the secondary winding 104 is significantly increased compared to the primary current in the primary winding 102.

[0053] The operation of the electric heater 100 will be explained in more detail with reference to Figures 3 and 4. Figure 3 illustrates a three-phase configuration, and Figure 4 illustrates only one phase of the configuration in Figure 1. The explanation in Figure 3 applies to each phase in a configuration employing a multi-phase configuration.

[0054] The flowing fluid 402 is introduced into the secondary winding 104 from the inlet 128. The flowing fluid 402 may include, but is not limited to, water, brine, or molten salt, and is selected based on a predetermined process to be supported. The flowing fluid 402 flows over the secondary winding 104 by first entering the inlet manifold 124 and then entering one of the first flow members 118. From the first flow member 118, the flowing fluid 402 enters a third flow member 122 connected to the first flow member 118, and flows through one of the pipes 132 to one of the uppermost end caps 304, where the flow of fluid 402 makes a 180-degree turn and enters another pipe 132, flowing downward. The flowing fluid 402 changes direction again by 180 degrees at the lowest end cap 304, returns to an upward direction, passes through another set of pipes 132, changes direction once more by 180 degrees after passing through another end cap 304, and finally enters a set of pipes 132 that directs the flow of fluid 402 downward, and then enters the second flow member 120 of the continuous flow channel to which the first flow member 118 belongs. The flowing fluid 402 passes through the second flow member 120, enters the outlet manifold 126, and finally exits the secondary winding 104 from the outlet 130.

[0055] The primary winding 102 includes multiple coils or windings, each coil wound around either the first core bar 210, the second core bar 212, or the third core bar 214. Power is applied to the primary winding 102 with a primary voltage and current. As described above, the power level of the power applied to the primary winding 102 is in the range of 1 MW to 1000 MW.

[0056] During operation, power is applied to the primary winding 102, and similar power is induced in the secondary winding 104 via the core 200. The number of coils in the primary winding 102 and the number of first flow members 118 and second flow members 120 are selected so that a predetermined voltage and current level is obtained in the secondary winding 104 for the voltage and current applied to the primary winding 102. For example, if the primary winding operates at 45kV and carries a primary current of 25A, the power level will be approximately 1.1MW. If the coil ratio between the primary winding 102 and the secondary winding 104 is 100:1, the resulting voltage in the secondary winding 104 will be approximately 450 volts and a secondary current of approximately 2500A will flow, which is then distributed among several parallel continuous flow paths. This large current flowing through the continuous channel of the secondary winding 104 heats the first flow member 118, the second flow member 120, and the third flow member 122, and then heats the fluid 402 flowing through the continuous channel. The extended length of the third flow member 122, which includes multiple bends (three 180-degree bends in the illustrated example), further heats the flowing fluid 402. By using different lengths, numbers of tubes, tube sizes, and the number of bends in the tubes, the level of heating applied to the flowing fluid 402 can be selected for the electric heater 100 in question. In other words, the electric heater 100 can be sized to produce a desired amount of fluid at a desired temperature.

[0057] In assembling the electric heater 100, first, a core 200 is assembled by stacking multiple laminates 202 in the stacking direction. In the illustrated configuration, the stacking direction is vertical, but other configurations are also possible. Each laminate is formed and stacked as is well known in the field of large-scale electrical machinery and transformers. Next, the primary winding 102 is arranged around the core according to the design. When a single-phase heater is used, a single primary winding 102 is applied to the core 200. In the case of a multi-phase configuration, the primary winding 102 includes multiple phase windings such as a first phase winding, a second phase winding, and a third phase winding. The number of coils in each phase winding is selected in conjunction with the number of coils (continuous flow paths) in the secondary winding 104 in order to obtain the desired secondary voltage and secondary current in the secondary winding 104.

[0058] The first flow member 118 and the second flow member 120 are then positioned around the core 200 and the primary winding 102. The first flow member 118 is connected to the inlet manifold 124, and the second flow member 120 is connected to the outlet manifold 126. In some configurations, the inlet manifold 124 and the outlet manifold 126 are connected to each other, allowing the first flow member 118, the second flow member 120, the inlet manifold 124, and the outlet manifold 126 to be installed as a single component such that the inlet manifold 124 and the outlet manifold 126 are positioned below the core 200, and the open second ends of the first flow member 118 and the second flow member 120 are positioned near or above the top of the core 200.

[0059] The third flow member 122 is assembled individually so that it has two open ends (the inlet and outlet are near the bottom end). The third flow member 122 is then attached to the open ends of the first flow member 118 and the second flow member 120 to complete the continuous flow path and the secondary winding 104.

[0060] The configuration illustrated here is advantageous from a maintenance standpoint for several reasons. Each pipe 132 of the third flow member 122 is the most prone to deterioration and requires regular maintenance. These items are located on top of the electric heater 100 and are in a position where they can be easily removed. The next most likely components to require maintenance are the first flow member 118, the second flow member 120, the inlet manifold 124, and the outlet manifold 126. These can also be easily removed with minimal disassembly of the other components. Finally, the components that are more difficult to reach, namely the core 200 and the primary winding 102, are the only components that would require disassembly of the other components to reach, repair, or replace them. In short, the illustrated configuration is easy to maintain and repair.

[0061] Figure 5 shows a flow-through electric heater 500 similar to the configuration described with respect to Figures 1 to 4. The flow-through electric heater 500 includes a primary winding 502 formed around a core 522 which is substantially the same as described with respect to Figure 4, and a secondary winding 504 positioned adjacent to the primary winding 502 and the core 522.

[0062] The secondary winding 504 includes a first flow-through member 506, a second flow-through member 508, an upper connector 510, and a lower connector 512, which cooperate to form a complete winding. In the illustrated configuration, the first flow-through member 506 and the second flow-through member 508 are substantially the same and include one or more inlets 514 at the first end of the flow-through electric heater 500 and one or more outlets 516 at the opposite end of the flow-through electric heater 500. In the illustrated configuration, the inlets 514 are located at the lowest end of the flow-through electric heater 500, but may be located at the upper end if necessary. Similarly, the positions of the outlets 516 may be reversed if necessary.

[0063] Each of the first flow-through member 506 and the second flow-through member 508 is surrounded by an insulating material 518 to improve the efficiency of the heating process. In addition, support members 520 are periodically arranged along the vertical direction to provide additional support to the components of the flow-through electric heater 500. A cover 524 may be provided to protect the internal components from the environment.

[0064] The flow-through electric heater 500 operates in the same manner as described for the electric heater 100. When power is applied to the primary winding 502, a current is induced in the secondary winding 504. The current flows through the first flow-through member 506 and the second flow-through member 508, and through the upper connector 510 and the lower connector 512 between the first flow-through member 506 and the second flow-through member 508, causing them to heat up.

[0065] The fluid to be heated is introduced into the first flow-through member 506 and the second flow-through member 508 through the inlet 514. As the fluid passes through each of the first flow-through member 506 and the second flow-through member 508, it is heated by the heat generated by the resistance to the current flowing through the secondary winding 504. The fluid then exits the first flow-through member 506 and the second flow-through member 508 through the outlet 516. In the illustrated configuration, each of the first flow-through member 506 and the second flow-through member 508 includes two inlets 514, from which four individual tubes are fed into each of the first flow-through member 506 and the second flow-through member 508, and then exit through four separate outlets 516. It should be noted that the number of inlets 514, the number of tubes, and the number of outlets 516 can be changed and are not important to the present invention. In other words, the inlet 514, outlet 516, and the quantity of pipes are selected in terms of convenience, efficiency, and other parameters.

[0066] The flow-through electric heater 500 includes a complete secondary winding 504 without any tubing or other components attached to the top of the first flow-through member 506 and the second flow-through member 508. That is, a meandering tubing as shown in Figures 1 to 4 may be used as needed. Furthermore, tubing that does not need to be conductive may be attached as needed, since these tubings do not form part of the secondary winding 504. In addition, the outlet 516 may be connected to various other components or tubing through which current is not desired.

[0067] Figure 6 shows another configuration of the toroidal electric heater 600 that operates in a similar manner to the laminated core structure described in Figures 1 to 5. In the configuration of Figure 6, the magnetic core 606 is constructed by winding one or more strips of magnetic laminate to form an elliptical, rounded rectangular, or “racetrack” shape. This wound core 606 has a longitudinal direction parallel to the long axis of the tube 610 (i.e., towards the back of the page in Figure 6). For each laminate, the length of the core 606 towards the back of the page in Figure 6 can be 50 to 150 cm, and other lengths are also possible. Several core modules 612, each defined by stacking one or more laminates in the longitudinal direction, can be stacked to extend the length of the core 606 as required for a particular application.

[0068] Continuing to refer to Figure 6, two core modules 612 are arranged adjacent to each other, in this case the long side of one core module 612 is adjacent to the similar long side of the other core module 612, defining a central core bar 614 having two apertures 616, with one aperture 616 on each side of the core bar 614.

[0069] The primary winding 602 extends around the central core bar 614, forming a closed primary winding 602. The secondary winding 604, in the form of a flow pipe 604, also forms a closed electrical circuit around the central core bar 614.

[0070] The thermal insulation material 608 is placed around the secondary winding 604, thermally isolating the secondary winding 604 from the primary winding 602 and laminate that constitute the core module 612. During operation, the current in the primary winding 602 induces a current in the secondary winding 604, particularly in the tube 610. The current in the secondary winding 604 heats the tube 610, and the fluid flowing through it is heated. The thermal insulation material 608 protects the primary winding 602 and the core module 612 from this heat.

[0071] The electric heater described here is suitable for efficient operation at very high power levels, exceeding 1 MW and up to approximately 1000 MW. In addition, this configuration can be manufactured inexpensively and is easy to maintain.

[0072] Figure 7 shows another configuration of an electric heater, in the form of a single-phase heater 700. It should be noted that "single-phase heater" means that the primary winding is provided as a single phase connected to a single-phase power supply or to a single phase connected to a multi-phase power supply. That is, a single-phase heater 700 as shown in Figure 7 can be used with a single-phase power supply. Also, if a three-phase power supply is available, three single-phase heaters 700 as shown in Figure 7 can be used, each of which has a primary winding 706 powered from one of the available power phases. In this way, multiple individual single-phase heaters 700 can be used in conjunction with a single multi-phase or three-phase power supply. Naturally, a single core with a three-phase winding similar to that shown in Figure 1 can also be used with a multi-phase or three-phase power supply.

[0073] Referring to Figure 7, the single-phase heater 700 includes a core 702, a primary winding 706, and a secondary winding 708. The core 702 includes a plurality of laminates stacked in the stacking direction 716 to a predetermined height or length. The core 702 defines a core envelope 704 that surrounds the laminates and may extend slightly beyond the laminates. Generally, the core envelope 704 is a region that encloses the laminates and may extend to a point where the magnetic field of the core maintains sufficient strength to function as a magnetic core. The shape of the laminates, and therefore the shape of the core 702, is selected according to a predetermined design such that the illustrated core 702 has a central bar 726 and two outer bars 728. Each outer bar 728 cooperates with the central bar 726 to define a core aperture 730 between them. Thus, the core 702 is very similar to the core 200 and can operate as a single-phase core or a three-phase core as needed.

[0074] The primary winding 706 comprises a plurality of wires, bars, or other conductors capable of transmitting a predetermined amount of power (e.g., 1 to 1000 MW, preferably 10 to 100 MW) in a manner that carries a primary current 732. As shown in Figure 7, the primary winding 706 includes one or more loops extending around the central bar 726, with a portion of each loop located within each of the core apertures 730, so that most, if not all, of the primary winding 706 is located within the core envelope 704. As described, the primary winding 706 is connected to a power source that operates to supply the predetermined power.

[0075] The secondary winding 708 includes a core flow member 710 and an external flow member 712 connected to each other to define a continuous flow path 724 for both the flowing fluid 714 and the flowing secondary current 734. The core flow member 710 includes one or more tubes arranged in a U-shape so that most, if not all, of the core flow member 710 is located within the core envelope 704. Specifically, the core flow member 710 includes lengthwise portions of two tubes that extend in the stacking direction and are located within the core aperture 730.

[0076] The external flow member 712 includes one or more pipes / tubes arranged in a meandering pattern. The number, size, length, and arrangement of the pipes in the external flow member 712 are selected to achieve a predetermined heating level of the flowing fluid 714.

[0077] One end of the external flow member 712 is connected to the core flow member 710 via a power connector 722. The power connector 722 acts as a conductor that allows communication of the flowing fluid 714 and ensures that a closed circuit is formed when the core flow member 710 and the external flow member 712 are connected. The second end of the external flow member 712 is connected to the core flow member 710 and defines an inlet 718 and an outlet 720. Each of the inlet 718 and the outlet 720 is formed either as part of the core flow member 710 or the external flow member 712, or as a single part or two separate parts attached to the core flow member 710 or the external flow member 712. The flowing fluid 714 does not flow out of the outlet 720 and return to the inlet 718, but the inlet 718 and the outlet 720 must be electrically connected to each other so that a closed circuit can be formed and a secondary current 734 can flow.

[0078] During operation, the single-phase heater 700 in Figure 7 receives power from a single-phase power supply or a single phase from a multi-phase power supply, and directs that power to the primary winding 706, resulting in the flow of a primary current 732.

[0079] The primary current 732 flowing through the primary winding 706 generates a magnetic field in the core 702, which in turn induces a secondary current 734 flowing through the secondary winding 708. Thus, the only interaction between the primary winding 706 and the secondary winding 708 arises as a result of the magnetic interaction between the primary winding 706, the secondary winding 708, and the core 702.

[0080] The flowing secondary current 734 flows along a closed circuit or continuous flow path 724 defined by the inlet 718, core flow member 710, power connector 722, external flow member 712, and outlet 720, heating the pipes that define the core flow member 710 and the external flow member 712.

[0081] The flowing fluid 714 is introduced into the secondary winding 708 at the inlet 718, flows through the core flow member 710, the power connector 722, and the external flow member 712, and exits from the secondary winding 708 at the outlet 720. As the flowing fluid 714 flows through the secondary winding 708, it is heated by the tubes along the flow.

[0082] While exemplary embodiments of this disclosure have been described in detail, those with ordinary skill in the art will understand that various modifications, substitutions, alterations, and improvements to the disclosure may be made without departing from the spirit and scope of the disclosure in its broadest form.

[0083] Nothing in the description in this application should be interpreted as meaning that any particular element, step, action, or function is an essential element that should be included in the claims, and the scope of post-patent subject matter is defined solely by the permitted claims. Furthermore, none of the claims are intended to introduce means-plus-function claim interpretation, except when the word "means for" is followed by a participle.

Claims

1. It is an electric heater, A core having a first surface and a second surface separated from the first surface in the stacking direction, defining a core envelope, A primary winding is arranged around the core and magnetically connected to the core, and is configured to operate at a power level exceeding 1 MW to generate a flow of primary current. A core flow member is magnetically connected to the core and arranged to surround a part of the core, An external flow member is positioned outside the core envelope and connected to the core flow member, defining a continuous flow path between the inlet and outlet. The core flow member and the external flow member cooperate to define the secondary winding. An electric heater comprising a fluid that flows to be supplied to the inlet and recovered from the outlet, and is heated in response to a secondary current that flows through the secondary winding, induced by the flow of the primary current.

2. The core includes a plurality of laminates stacked in the stacking direction, and the laminates are organized to define a central bar, a first outer bar, and a second outer bar. The electric heater according to claim 1, wherein the primary winding surrounds the central bar and passes through a first core aperture between the central bar and the first outer bar, and a second core aperture between the central bar and the second outer bar.

3. The electric heater according to claim 2, wherein the core flow member surrounds a part of the central bar and extends through the first core aperture and the second core aperture.

4. The electric heater according to claim 1, wherein the inlet and outlet are located outside the core envelope.

5. The electric heater according to claim 1, wherein the external flow member includes a plurality of continuous pipes, each of which is arranged along a meandering path.

6. The core defines a first core bar, a second core bar, and a third core bar. The first core bar and the second core bar cooperate to define the first core aperture, and the second core bar and the third core bar cooperate to define the second core aperture. The primary winding includes a first phase winding extending around the first core bar, a second phase winding extending around the second core bar, and a third phase winding extending around the third core bar. The electric heater according to claim 1, wherein the secondary winding includes a first continuous flow path extending around the first core bar, a second continuous flow path extending around the second core bar, and a third continuous flow path extending around the third core bar.

7. The electric heater according to claim 1, wherein the power level is between 10 MW and 100 MW.

8. The core includes a first core portion defining a first core aperture and a second core portion, separate from the first core portion, defining a second core aperture. The first core portion and the second core portion are arranged adjacent to each other, and a part of the first core portion and a part of the second core portion cooperate to define a central bar. The electric heater according to claim 1, wherein the primary winding is arranged to surround the central bar.

9. The electric heater according to claim 1, wherein the first core portion is formed from a continuous strip of magnetic material wound to form an elliptical first core portion.

10. The core includes a central bar, a first outer bar, and a second outer bar. The primary winding surrounds the central bar and passes through a first core aperture between the central bar and the first outer bar and a second core aperture between the central bar and the second outer bar. The core flow member surrounds a portion of the central bar and extends through the first core aperture and the second core aperture. The electric heater according to claim 1, wherein the core, the primary winding, and the secondary winding cooperate to define a single-phase heater.

11. The single-phase heater is the first single-phase heater, The electric heater further includes a second single-phase heater separate from the first single-phase heater, and a third single-phase heater separate from the first single-phase heater and the second single-phase heater. The electric heater according to claim 10, wherein a first phase of the three-phase power supply supplies power to the primary winding of the first single-phase heater, a second phase of the three-phase power supply supplies power to the primary winding of the second single-phase heater, and a third phase of the three-phase power supply supplies power to the primary winding of the third single-phase heater.

12. The electric heater according to claim 1, wherein the sole interaction between the primary winding and the secondary winding is a result of a magnetic interaction with the core.

13. A method for heating a flowing fluid, Applying a primary winding to a core having a core envelope, To arrange a secondary winding adjacent to the core, The secondary winding includes a core flow member surrounding a portion of the core and an external flow member positioned outside the core envelope, wherein the core flow member and the external flow member cooperate to define a continuous flow path between the inlet and outlet. The fluid is to flow from the inlet through the continuous flow path to the outlet. A primary current is supplied to the primary winding with a primary voltage that provides a power level of at least 1 MW. To induce the flow of a secondary current in the secondary winding in response to the flow of the primary current, Heating the secondary winding in response to the flow of the secondary current, A method comprising heating the fluid flowing in response to heating the secondary winding.

14. This further includes stacking multiple laminates in the stacking direction, The method according to claim 13, wherein each of the laminates is formed from a magnetic material.

15. The method according to claim 13, further comprising winding a continuous strip of magnetic material into a toroidal shape to form the core.

16. To provide the core including a first core bar, a second core bar, and a third core bar, The first core bar and the second core bar cooperate to define a first core aperture, and the second core bar and the third core bar cooperate to define a second core aperture. The first phase winding of the primary winding is wound around the first core bar, the second phase winding of the primary winding is wound around the second core bar, and the third phase winding of the primary winding is wound around the third core bar. The method according to claim 13, further comprising arranging a first continuous flow path of the secondary winding around the first core bar, arranging a second continuous flow path of the secondary winding around the second core bar, and arranging a third continuous flow path of the secondary winding around the third core bar.

17. The core is further formed to include a central bar, a first outer bar, and a second outer bar, Applying the primary winding includes surrounding the central bar, passing the primary winding through the first core aperture between the central bar and the first outer bar, and through the second core aperture between the central bar and the second outer bar. The arrangement of the secondary winding includes enclosing a portion of the central bar and extending the secondary winding through the first core aperture and the second core aperture, The method according to claim 13, wherein the core, the primary winding, and the secondary winding cooperate to define a single-phase heater.

18. The single-phase heater is connected to the first phase of the three-phase power supply. Connecting the second single-phase heater to the second phase of the three-phase power supply, The further includes connecting a third single-phase heater to the third phase of the three-phase power supply, The method according to claim 17, wherein the single-phase heater, the second single-phase heater, and the third single-phase heater are separated from each other.

19. The method according to claim 13, comprising operating an electric heater at a power level between 10 MW and 100 MW.

20. The secondary winding includes a core flow member and an external flow member, Arranging the secondary winding includes arranging the core flow member so as to surround a part of the core, and attaching the external flow member to the core flow member to define the continuous flow path between the inlet and the outlet, The method according to claim 13, wherein the external flow member is arranged outside the core envelope.

21. The method according to claim 20, further comprising forming the external flow member to include a meandering path.

22. It is an electric heater, A core oriented to define a first surface and a second surface opposite the first surface, A primary winding is positioned adjacent to the core and is capable of operating at a power level exceeding 1 MW to generate a primary current flow. A first flow member extends around the first portion of the core and defines an inlet, A second flow member extends around a second portion of the core that is different from the first portion and defines an outlet, A third flow member is positioned adjacent to the first surface and connected to the first flow member and the second flow member to complete a continuous flow path between the inlet and the outlet, The first flow member, the second flow member, and the third flow member cooperate to define a portion of the secondary winding. A fluid that flows to be supplied to the inlet and recovered from the outlet, An electric heater in which the flowing fluid is heated in response to a secondary current flowing in the secondary winding, which is induced by the flow of the primary current.

23. The electric heater according to claim 22, wherein the primary winding, the core, and the secondary winding are arranged adjacent to each other and interact with each other via a magnetic field.

24. The electric heater according to claim 22, further comprising a power connector connected to the first flow member and the second flow member.

25. The core includes a plurality of laminates stacked in a first direction, The electric heater according to claim 22, wherein each of the laminates is formed from a magnetic material.

26. The electric heater according to claim 22, wherein the core consists of a continuous strip of magnetic material and is wound to form a toroidal core.

27. The aforementioned core defines three core bars and two core apertures. The primary winding includes a first phase winding extending around a first core bar among the three core bars, a second phase winding extending around a second core bar among the three core bars, and a third phase winding extending around a third core bar among the three core bars. The electric heater according to claim 22, wherein the secondary winding includes a first continuous flow path extending around the first core bar, a second continuous flow path extending around the second core bar, and a third continuous flow path extending around the third core bar.

28. The core includes a central core bar, a first outer bar, and a second outer bar. The central core bar cooperates with the first outer bar to define a first core aperture and cooperates with the second outer bar to define a second core aperture. The primary winding includes a single-phase winding extending around the central core bar. The secondary winding includes a first continuous flow path extending around the central core bar, The electric heater according to claim 22, wherein a portion of the primary winding and the secondary winding respectively passes through the first core aperture and the second core aperture, respectively.

29. The electric heater according to claim 22, wherein the power level is between 10 MW and 100 MW.

30. The electric heater according to claim 22, wherein the third flow member includes a first pipe arranged along a meandering path extending between the first flow member and the second flow member.

31. The third flow member further includes a plurality of tubes and a plurality of end caps, Each of the aforementioned plurality of pipes is straight, The electric heater according to claim 22, wherein the plurality of pipes and the plurality of end caps cooperate to define a meandering path extending between the first flow member and the second flow member.

32. It further includes an inlet manifold and an outlet manifold, The electric heater according to claim 22, wherein the inlet of the first flow member is connected to the inlet manifold, and the outlet of the second flow member is connected to the outlet manifold.

33. The first flow member is one of a plurality of first flow members, each of which includes the inlet connected to the inlet manifold. The electric heater according to claim 32, wherein the second flow member is one of a plurality of second flow members, each of which includes the outlet connected to the outlet manifold.

34. The third flow member is one of a plurality of third flow members, and each of the third flow members is connected to a corresponding one of the first flow members and a corresponding one of the second flow members to define one of a plurality of continuous flow paths. The electric heater according to claim 33, wherein each of the plurality of continuous flow paths is fluidly isolated from the other continuous flow paths, except for the inlet manifold and the outlet manifold.

35. The electric heater according to claim 22, wherein the third flow member is removable from the first flow member and the second flow member without disassembling the core and the primary winding.

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