System and method for heating fluid using galvanically isolated electrical energy having zero voltage to ground

Abstract

A thermal control system for a fluid heating system including a tube defining an inlet and an outlet includes a galvanically isolated power supply to be electrically connected to the tube to provide an electric energy to heat the tube. The thermal control system also includes a power controller to control the galvanically isolated power supply. The power controller is to adjust an electric current to be provided by the galvanically isolated power supply to the tube. The galvanically isolated power supply is to provide at least two low voltage terminals at the tube and at least one high voltage terminal at the tube. The at least one high voltage terminal is disposed between the at least two low voltage terminals. The galvanically isolated power supply is to provide substantially zero voltage at the inlet and substantially zero voltage at the outlet of the tube.

Description

SYSTEM AND METHOD FOR HEATING FLUID USING GALVANICALLYISOLATED ELECTRICAL ENERGY HAVING ZERO VOLTAGE TO GROUNDCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. provisional application number 63 / 456,302 filed on March 31 , 2023. The disclosure of the above application is incorporated herein by reference.FIELD

[0002] The present disclosure relates to a method and system for direct electrical heating of a fluid system.BACKGROUND

[0003] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0004] In some industries, a system for heating fluid employs multiple tubes carrying fluid within, where the tubes are fire heated. Unfortunately, such fire heat treatment can emit greenhouse gases and can cause uneven temperature profiles across the tubes, which can cause inefficient operation of the system.SUMMARY

[0005] This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.

[0006] In one form of the present disclosure, a fluid heating system comprises a tube defining a fluid passage and comprising an electrically conductive material, wherein the tube defines an inlet and an outlet to receive and expel fluid. A set of power systems includes a galvanically isolated power supply electrically connected to the tube to provide an electric energy to heat the tube and a power controller configured to operate the galvanically isolated power supply to provide the electric energy to the tube. The power controller is configured to adjust an electric current to be provided by the galvanically isolated power supply, wherein the set of power systems is configured to control the electrical energy to have substantially zero voltage at the inlet and substantially zero voltage at the outlet.

[0007] In variations of this fluid heating system, which may be implemented individually or in any combination: a sensor system includes a pluralityof sensors to detect one or more operational parameters, wherein the operational parameters include one or more temperatures proximate the tube, one or more electrical characteristics, or a combination thereof, and the electrical current to be provided is based on at least one of the one or more operational parameters; the electrical characteristics include at least one of a ground electric current measured as an electric current traveling to ground, an isolation voltage measured as a voltage provided by the galvanically isolated power supplies of the set of power systems, and a ground voltage measured as a voltage between of at least one electrically conductive surface and ground; the set of power systems includes a first power system and a second power system, a first galvanically isolated power supply of the first power system is electrically connected at a first portion and a second portion of the tube, and a second galvanically isolated power supply of the second power system is electrically connected at the second portion and a third portion of the tube; the second portion of the tube is located between the first portion of the tube and the third portion of the tube; the second portion of the tube is located based on a desired thermal profile of the tube; the set of power systems includes a plurality of power systems, and the plurality of power systems are electrically connected to the tube in a plurality of zones, wherein each power system provides the electrical energy at a respective zone; at least one galvanically isolated power supply for at least one power system from among the plurality of power systems includes a transformer having a dual voltage output; at least one galvanically isolated power supply for at least one power system from among the plurality of power systems includes a transformer having a dual voltage output connected to the tube; wherein the set of power systems includes one power system, and the galvanically isolated power supply includes a transformer having a dual voltage output connected to the tube; the tube is connected to a fluid input manifold and a fluid output manifold, the set of power systems is connected to at least a first portion of the tube and a second portion of the tube, a first distance is defined between the fluid input manifold and a first portion of the tube closest to the fluid input manifold and connected to the set of power systems, and a second distance is defined between the fluid output manifold and a second portion of the tube closest to the fluid output manifold and connected to the set of power systems, and the first distance and the second distance are adapted to provide a desired amount of impedance between a respective electrically conductive surface and ground; the tube and the set of power systems form a heater subsystem, and the fluid heating system further comprises aplurality of the heater subsystems; and the plurality of the heater subsystems are electrically isolated from each other by way of the galvanically isolated power supplies.

[0008] In yet another form of the present disclosure, a thermal control system for a fluid heating system includes a tube defining an inlet and an outlet, the thermal control system comprising a galvanically isolated power supply electrically connected to the tube to provide an electric energy to heat the tube, and a power controller configured to control the galvanically isolated power supply. The power controller is configured to adjust an electric current to be provided by the galvanically isolated power supply to the tube. The galvanically isolated power supply is configured to provide at least two low voltage junctions at the tube and at least one high voltage junction at the tube, and the at least one high voltage junction is disposed between the at least two low voltage junctions to provide substantially zero voltage at the inlet and substantially zero voltage at the outlet of the tube.

[0009] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.DRAWINGS

[0010] In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

[0011] FIG. 1A illustrates a fluid heating system including a plurality of tubes and a plurality of power systems in accordance with the present disclosure;

[0012] FIG. 1 B is a top view of the plurality of tubes in accordance with the present disclosure;

[0013] FIG. 2 illustrates a heater subsystem including a tube and a set of power systems in accordance with the present disclosure;

[0014] FIG. 3 illustrates another form of a heater subsystem in accordance with the present disclosure; and

[0015] FIG. 4 illustrates another form of a heater subsystem having a dual output transformer.

[0016] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.DETAILED DESCRIPTION

[0017] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0018] According to the teachings of the present disclosure, fire (or natural gas) heated tubes are replaced with direct electric energy in which electrical energy is applied directly to the tube, which is made of a conductive material such as stainless steel, by way of example. Each tube can be equipped with its own electrical power system for heating, and the current to the tube can be adjusted to control the temperature of a fluid inside the tube. However, when using direct electric energy, each tube is to be electrically isolated from other tubes and from a main power source connected to each power system for each of the tubes.

[0019] In one form, a fluid heating system of the present disclosure includes a plurality of tubes, and each tube is heated by electric energy applied by a set of power systems connected to the tube. The set of power systems galvanically isolate the tube from, at least, other tubes of the fluid heating system and from the power source. Furthermore, the set of power systems is advantageously configured to provide zero voltage to ground. That is, the sum of voltage applied by the set of power systems is zero to reduce the amount of electric current flowing to ground, while providing a full range of voltage and / or current levels to the tube. As used herein, the term "fluid" should be construed to mean liquid, gas, or plasma, among others.

[0020] Referring to FIGS. 1 A,1 B, and 2, an example fluid heating system 100 includes a plurality of tubes 102 and a plurality of power systems 104 configured to heat fluid flowing within and through the tubes 102. A selected tube 102 is electrically connected to a set of power systems 104 from among the plurality of power systems 104, such as power systems 104A and 104B in the example of FIG. 2. Generally, fluid flows through the tube 102, and the set of power systems 104 applies electric energy to the tube 102 to heat the fluid therein. The set of power systems 104 form a thermal control system to control a temperature or more specifically, a thermal profile, of the tube 102 for heating the fluid. Together, the tube 102 and the set of power systems 104 form a heater subsystem, where the fluid heating system 100 includes a plurality of the heater subsystems. As described herein, the plurality of the heater subsystems are electrically isolated from each other, at least, by galvanicallyisolated power supplies and by providing a substantially zero sum voltage between opposite ends of the tube 102, as described in greater detail below.

[0021] In one form, the tube 102 defines a fluid passage and comprises electrically conductive material. The tube 102 further defines an inlet 112 connected to a fluid input manifold 116 and an outlet 114 connected to a fluid output manifold 118 to receive and expel the fluid. In one form, the manifolds 116 and 118 are electrically grounded. For purposes of clarity, only one tube 102 is illustrated, but it should be readily understood that multiple tubes 102 may be connected to the same fluid input manifold 116 and the fluid output manifold 118 while remaining within the scope of the present disclosure.

[0022] In an example application, the fluid heating system 100 is provided for a reactor system that employs a catalyst 119 to produce a chemical reaction within the tubes 102 when being heated by the electrical energy. Fluid enters the tube 102 through the fluid input manifold 116 and a byproduct of the chemical reaction is expelled via the fluid output manifold 118. The direction of the fluid and byproduct are provided with arrows 120 in FIG. 2. While the fluid heating system 100 having the tubes 102 and the power systems 104 is described with respect to a reactor system, the fluid heating system 100 of the present disclosure may be provided with other fluid heating applications, both with and without chemical reactions, and should not be limited to a reactor system as illustrated and described herein. For example, the fluid heating system 100 may be provided for a reactor system not employing a catalyst. In another example, the system 100 is employed for heating water within the tube 102 to generate steam. Accordingly, the fluid heating system 100 can be used for other suitable applications in which direct electrical energy as illustrated and described herein is employed to heat tubes, and thus the fluid flowing within the tubes.

[0023] In one form, the plurality of power systems are configured to provide high electric current (e.g., 1 ,000-10,000 Amps) directly to the tubes 102 and, as described herein, the electric current is controlled between at least two low voltage terminals or cold terminals of the set of power systems 104 connected to the selected tube 102. More particularly, in the example of FIG. 2, the set of power systems 104A, 104B are electrically connected to portions 122 of the tube 102 (e.g., portions 122A, 122B, 122C in FIG. 2) to apply electrical energy at the respective portions 122 of the tube 102. Each power system 104A, 104B includes a galvanically isolated (G-l) power supply 106A, 106B and a power controller 108A, 108B for controlling the G-l powersupply 106A, 106B. In the following, the G-l power supplies 106A, 106B may collectively be referred to as a “G-l power supply 106” and the power controllers 108A, 108B may collectively be referred to as a “power controller 108.” In one form, if the set of power systems 104 includes two or more power systems 104, the set of power systems 104 defines a plurality of zones, where each power system 104 provides electrical energy at a respective zone. For example, the power supply 106A defines a zone A generally between portions 122A and 122B and the power supply 106B defines zone B generally between portions 122B and 122C. While FIG. 2 illustrates the set of power systems 104 including two power systems 104A, 104B, the set of power systems may include one or more power systems 104 and should not be limited to two power systems.

[0024] The power controller 108 is configured to operate the G-l power supply 106 to provide the electric energy to the tube 102. More specifically, the power controller 108 is configured to control a temperature of the tube 102 by adjusting an electric current to be provided by the G-l power supply 106 based on one or more operational parameters. In one form, as detailed below, the power controllers 108 of the set of power systems 104 are configured to provide zero voltage to ground to reduce the amount of electric current traveling to ground. In one form, the power controller 108 includes a power converter electrically coupled to a power source (not shown), such as a single-phase alternating current (AC) or direct current (DC) power source, to adjust the power from the power source to a desired level (e.g., desired voltage and / or desired current). The power controller 108 may also include other circuitry such as a communication interface and / or a power safety switch (not shown). The communication interface is configured to communicate with external devices such a system controller 128 that provides an operational signal indicative of the amount of electric energy (i.e., power, voltage, and / or current) to be provided to the tube 102 by the G-l power supply 106. The power safety switch is configured to turn power OFF to the G-l power supply 106 in response to an electrical characteristic, described below, being at or above a desired threshold.

[0025] As shown, the G-l power supply 106 is electrically connected to multiple portions 122 of the tube 102 to provide the electric energy to heat the tube 102. In one form, among other components, the G-l power supply 106 includes a transformer 107 (shown as 107A and 107B in FIG. 2) configured to receive adjustable power from the power controller 108. The transformer 107 provides the electric energyto the tube 102 while electrically isolating the electric energy being applied from other devices, such as, the power source and the power controller 108. Thus, the G-l power supply 106 is operable to provide a vast range of voltage and / or electric current regardless of the type of power source being employed. Additional details regarding the power systems 104 is described further below.

[0026] In one form, the fluid heating system 100 further includes a sensor system that includes a plurality of sensors to detect one or more of the operational parameters, which may include, but is not limited to, temperature proximate the tube 102, electrical characteristics, and / or fluid characteristics. For example, the temperature of the tube 102 may be measured by one or more temperature sensors 130A provided at the tube 102. The electrical characteristics may include: a ground electric current (IGND) measured as the electric current traveling to ground; a line current (ILN); a load current (ILD) measured between terminals of the G-l power supply 106 (e.g., terminals of transformer); a ground voltage (VGND) measured between the tube 102 and ground; a line voltage (VLN); a load voltage (VLD) measured between terminals of the G-l power supply 106 (e.g., terminals of transformer). One or more of the electrical characteristics are measured by sensors 130B, which are provided as current and / or voltage sensors in one form of the present disclosure. The fluid characteristics may include, by way of example, fluid pressure, fluid flow rate, mass flow rate, fluid composition, turbulence, and fluid temperature, among others. One or more of the fluid characteristics may be measured by sensors 130C. The sensors 130A, 130B, 130C are collectively referenced as a sensor system 130, and are provided for illustrative purposes and are not intended to represent actual physical connection of the sensor system 130 in the system 100. While specific operational parameters are provided, it should be readily understood that not all of the operational parameters described herein need to be employed and / or other operational parameters may be included, such as, but not limited to, temperature at the manifolds 116, 118.

[0027] In one form, during operation, the system controller 128 processes the operational parameters to determine the amount of energy to be provided to each tube 102. The system controller 128 may be configured in various suitable ways for determining the current to be applied by the G-l power supply 106 and provide the operational signals to the set of power systems 104. For example, the system controller 128 is configured to include a closed-loop control routine defined todetermine the amount of electric current to apply based on one or more operational setpoints such as, but not limited to, temperature setpoint, voltage setpoint, current setpoint, and / or power setpoint. In another example, the system controller 128 is configured to include an open-loop control routine to provide a desired amount of current for a period of time. It should be readily understood that other control routines may be employed for the system controller 128, and the system controller 128 should not be limited to the examples provided herein. In one form, the system controller 128 may be part of the thermal control system to control the power systems 104. That is, in some applications, the power systems 104 of the present disclosure may be employed with a preexisting system controller. In other applications, the system controller 128 may be provided with the power systems 104.

[0028] To control the amount of electric current flowing to ground, the set of power systems 104 electrically connected to the tube 102 is configured to provide substantially zero voltage to ground. More particularly, in the example of FIG. 2, the voltage provided by the power supply system 104B is of substantially the same opposite voltage as the voltage provided by power supply system 104A. Specifically, the G-l power supply 106A is electrically connected at the portion 122A and the portion 122B of the tube 102, and the G-l power supply 106B is electrically connected at the portion 122B and the portion 122C of the tube 102. At least two terminals of the G-l power supplies 106A, 106B are connected such that the portion 122A and the portion 122C, which are arranged closest to the inlet 112 and the outlet 114, respectively, are low voltage terminals (i.e., substantially 0V) or, in other words, "cold" terminals. In addition, other terminals of the G-l power supplies 106A, 106B are connected such that the portion 122B, which is arranged between the portion 122A and 122C, is a high voltage terminal or, in other words, a "hot" terminal. Accordingly, the set of power systems 104A, 104B are arranged such that the voltage between portions 122A and 122B mirrors, or is the same as, the voltage between portions 122B and 122C. Accordingly, if the power system 104A provides 50V across portions 122A and 122B, the power system 104B provides -50V across portion 122B and 122C, such that the sum voltage between portions 122A and 122C is zero. Thus, the portions 122A and 122C provided closest to the inlet 112 and the outlet 114 are at about zero volts, respectively.

[0029] In one form, the set of power systems 104 is not required to provide a strict mirrored voltage to obtain substantially zero voltage to ground, asdescribed with respect to the example of FIG. 2. For example, FIG. 3 illustrates the tube 102 and the set of power systems 104A, 104B of FIG. 2, and further includes an additional power system 104C connected to the tube 102. The set of power systems 104 are connected such that: the power system 104A is electrically connected to portions 122A and 122B of the tube 102 defining a zone A; the power system 104B is electrically connected to portions 122B and 122C defining a zone B; and the power system 104C is electrically connected to portions 122C and 122D defining a zone C. The portions 122A and 122D are closest to the inlet 112 and the outlet 114 of tube 102, respectively, and thus the set of power systems 104 is connected to have two low voltage terminals connected to portions 122A and 122D (e.g., low voltage terminals of power system 104A and power system 104D are connected closest to the inlet 112 and the outlet 114, respectively). The high voltage terminals and other low voltage terminals of the set of power systems 104 are connected between the two low voltage terminals connected to portions 122A and 122D. The set of power systems 104 can be controlled in various suitable ways to provide the substantially zero voltage to ground. For example, the power system 104A is configured to provide 50V between portions 122A and 122B, the power system 104B is configured to provide -25V between portions 122B and 122C, and the power system 104C is configured to provide -25V between portions 122C and 122D. In yet another example, the power system 104A may provide 100V between 122A and 122B, the power system 104B is configured to provide -75V between portions 122B and 122C, and the power system 104C is configured to provide -25V between portions 122C and 122D, thereby providing a substantially zero voltage sum between portions 122A and 122C.

[0030] While specific voltages are provided herein, it should be readily understood that other voltage amounts may be provided. In the drawings, the portions 122 are provided as rectangular members to distinguish a section of the tube 102 that is connected to the G-l power supply from other portions of the tube 102. Furthermore, while the power systems 104 are illustrated as sharing portions 122 of the tube 102 (e.g., power systems 104A and 104B are both connected to portion 122B), the power systems 104 are not required to share connection portions. For example, with respect to FIG. 3, there may be a distance between the terminals of power system 104B and power system 104C.

[0031] In one form, the placement of the high voltage terminal(s) of the G-l power supply 106 is selected to provide a desired thermal profile for the applicationemploying the fluid heating system 100, and may be determined based on various parameters, such as but not limited to, a concentration of the catalyst and / or cold spots along the tube 102. For example, in the example application of FIG. 2, if the catalyst 119 is concentrated closer to the fluid output manifold 118, the hot terminals may be connected to a portion of the tube 102 closer to the portion 122C to concentrate the electric energy, and thus, the heat generated near the concentrated catalyst. It should be understood herein that any location that has a voltage different from ground, may be positive or negative.

[0032] In FIGS. 1A, 1 B, 2, and 3, the G-l power supply 106 of the power systems 104 includes a single output transformer 107, however, in one form, a multioutput transformer may also be used. For example, referring to FIG. 4, a power system 204 is provided for the tube 102 and is considered a set of power systems 204 for the tube 102. The power system 204 includes a G-l power system 206 and a power controller 208. The G-l power system 206 includes a dual voltage output transformer 207 having a primary coil and two secondary coils. In this configuration, one secondary coil is electrically connected to portions 122A and 122B of the tube 102 and the other secondary coil is electrically connected to portions 122B and 122C of the tube 102. The secondary coils are electrically connected to have portions 122A and 122C as low voltage terminals and portion 122B as the high voltage section. The G-l power system 206 is configured to provide a first voltage between portions 122A and 122B and provide a second voltage between portions 122B and 122C, where the second voltage is the negative value of the first voltage (e.g., first voltage is 100V and second voltage is -100V). Accordingly, the set of power systems for the tube 102 may include one power controller and one G-l power system. The power system 204 may be used in combination with the power systems 104 to form the set of power systems 104, 204 for heating the tube.

[0033] The amount of electric current flowing to ground may be further managed to inhibit wear to the overall fluid heating system 100 by providing a desired amount of impedance between low voltage terminals and ground. More particularly, the distances between the low voltage terminals and the fluid input manifold 116 and the fluid output manifold 118 is defined based on the desired impedance for the fluid heating system 100. For example, referring to FIG. 2, a first distance is defined between the fluid input manifold 116 and a portion of the tube 102 closest to the fluid input manifold 116 and connected to the set of power systems 104 (e.g., the portion122A in FIG. 2), and a second distance is defined between the fluid output manifold 118 and a second portion of the tube 102 closest to the fluid output manifold 118 and connected to the set of power systems 104 (e.g., portion 122C in FIG. 2). The first distance is generally identified by arrow 132 and the second distance is generally identified by arrow 134. The first distance and the second distance are adapted, or changed in length, to provide a desired amount of impedance between a respective electrically conductive surface of the tube 102 and ground, where the impedance reduces the electric current to ground. Accordingly, the location of terminals of the set of power systems 104 may be further selected to control the amount of electric current flowing to ground. In one example, the amount of electric current to ground may be controlled to be less than or equal to 10% of the electric current flowing in the tube 102.

[0034] In some variations, the fluid heating system 100 may further include a safety isolation transformer (not shown) to monitor current provided to ground. Specifically, the safety isolation transformer may be configured to perform a corrective action to inhibit current from exceeding a desired threshold, thereby reducing or inhibiting damage to the fluid heating system.

[0035] In the figures, the tube 102 is a long pipe, however, the tube 102 may be configured to have other suitable shape such as, but not limited to a “U” shape or a W shape. The set of power systems for the tube are arranged and connected to provide the zero voltage to ground in accordance with concept disclosed above.

[0036] Unless otherwise expressly indicated herein, all numerical values indicating mechanical / thermal properties, compositional percentages, dimensions and / or tolerances, or other characteristics are to be understood as modified by the word “about” or "approximately" in describing the scope of the present disclosure. This modification is desired for various reasons including industrial practice, material, manufacturing, and assembly tolerances, and testing capability.

[0037] As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

[0038] In this application, the term “controller” and / or “module” may refer to, be part of, or include: an Application Specific Integrated Circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixedanalog / digital integrated circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor circuit (shared, dedicated, or group) that executes code; a memory circuit (shared, dedicated, or group) that stores code executed by the processor circuit; other suitable hardware components (e.g., op amp circuit integrator as part of the heat flux data module) that provide the described functionality; or a combination of some or all of the above, such as in a system-on-chip.

[0039] The term memory is a subset of the term computer-readable medium. The term computer-readable medium, as used herein, does not encompass transitory electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); the term computer-readable medium may therefore be considered tangible and non-transitory. Non-limiting examples of a non-transitory, tangible computer-readable medium are nonvolatile memory circuits (such as a flash memory circuit, an erasable programmable read-only memory circuit, or a mask readonly circuit), volatile memory circuits (such as a static random access memory circuit or a dynamic random access memory circuit), magnetic storage media (such as an analog or digital magnetic tape or a hard disk drive), and optical storage media (such as a CD, a DVD, or a Blu-ray Disc).

[0040] The apparatuses and methods described in this application may be partially or fully implemented by a special purpose computer created by configuring a general-purpose computer to execute one or more particular functions embodied in computer programs. The functional blocks, flowchart components, and other elements described above serve as software specifications, which can be translated into the computer programs by the routine work of a skilled technician or programmer.

[0041] The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.

Claims

CLAIMSWhat is claimed is:

1. A thermal control system for a fluid heating system including a tube defining an inlet and an outlet, the thermal control system comprising: a galvanically isolated power supply configured to be electrically connected to the tube to provide an electric energy to heat the tube; and a power controller configured to control the galvanically isolated power supply, wherein the power controller is configured to adjust an electric current to be provided by the galvanically isolated power supply to the tube, wherein: the galvanically isolated power supply is configured to provide at least two low voltage terminals at the tube and at least one high voltage terminal at the tube, and the at least one high voltage terminal is disposed between the at least two low voltage terminals and configured to provide substantially zero voltage at the inlet and substantially zero voltage at the outlet of the tube.

2. The thermal control system of Claim 1 , further comprising: a sensor system including a plurality of sensors to detect one or more operational parameters, wherein: the one or more operational parameters include one or more temperatures proximate the tube, one or more electrical characteristics, or a combination thereof, and the electric current to be provided is based on at least one of the one or more operational parameters.

3. The thermal control system of Claim 2, wherein the one or more electrical characteristics include at least one of: a ground electric current measured as an electric current traveling to ground, an isolation voltage measured as a voltage provided by the galvanically isolated power supply, anda ground voltage measured as a voltage between at least one electrically conductive surface and ground.

4. The thermal control system of Claim 1 , wherein a first voltage between a first low voltage terminal of the at least two low voltage terminals and the at least one high voltage terminal at the tube mirrors a second voltage between a second low voltage terminal of the at least two low voltage terminals and the at least one high voltage terminal at the tube, wherein the first voltage and the second voltage sum to zero.

5. The thermal control system of Claim 1 , wherein a voltage between each of the at least two low voltage terminals and the at least one high voltage terminal at the tube sum to zero, and the at least one high voltage terminal at the tube is located based on a desired thermal profile of the tube.

6. The thermal control system of Claim 1 , wherein the galvanically isolated power supply includes a transformer having a dual voltage output.

7. The thermal control system of Claim 1 , wherein the galvanically isolated power supply includes at least one transformer having a dual voltage output connected to the tube.

8. The thermal control system of Claim 1 , wherein the inlet of the tube is configured to be connected to a fluid input manifold and the outlet of the tube is configured to be connected to a fluid output manifold, a first distance is defined between the fluid input manifold and a first low voltage terminal of the at least two low voltage terminals that is closest to the fluid input manifold, a second distance is defined between the fluid output manifold and a second low voltage terminal of the at least two low voltage terminals that is closest to the fluid output manifold, the first distance and the second distance are adapted to provide a desired amount of impedance between a respective electrically conductive surface and ground.

9. The thermal control system of Claim 1 , further comprising the fluid heating system, the fluid heating system comprising: the tube, the tube further defining a fluid passage and comprising an electrically conductive material; a set of power systems, each power system including: the galvanically isolated power supply electrically connected to the tube to provide an electric energy to heat the tube; and the power controller configured to operate the galvanically isolated power supply to provide the electric energy to the tube, wherein the set of power systems is configured to control the electric energy to have the substantially zero voltage at the inlet and the substantially zero voltage at the outlet.

10. The thermal control system of Claim 9, wherein: the set of power systems includes a first power system and a second power system, a first galvanically isolated power supply of the first power system is electrically connected at a first portion and a second portion of the tube, a second galvanically isolated power supply of the second power system is electrically connected at the second portion and a third portion of the tube, and the second portion of the tube is located between the first portion of the tube and the third portion of the tube and the second portion comprises the at least one high voltage terminal.

11. The thermal control system of Claim 10, wherein the set of power systems further includes a third power system having a third galvanically isolated power supply electrically connected at the third portion and a fourth portion of the tube, the second portion and the third portion of the tube being located between the first portion of the tube and the fourth portion of the tube, wherein respective voltages between the first portion and second portion of the tube, the second portion and third portion of the tube, and the third portion and the fourth portion of the tube sum to zero.

12. The thermal control system of Claim 9, wherein: the set of power systems includes a plurality of power systems; andthe plurality of power systems are electrically connected to the tube in a plurality of zones, wherein each power system provides the electric energy at a respective zone, wherein at least one galvanically isolated power supply for at least one power system from among the plurality of power systems includes a transformer having a dual voltage output.

13. The thermal control system of Claim 9, wherein the set of power systems includes one power system, and the galvanically isolated power supply includes a transformer having a dual voltage output connected to the tube.

14. The thermal control system of Claim 9, wherein: the tube is connected to a fluid input manifold and a fluid output manifold, the set of power systems is connected to at least a first portion of the tube and a second portion of the tube, a first distance is defined between the fluid input manifold and a first portion of the tube closest to the fluid input manifold and connected to the set of power systems, and a second distance is defined between the fluid output manifold and a second portion of the tube closest to the fluid output manifold and connected to the set of power systems, and the first distance and the second distance are adapted to provide a desired amount of impedance between a respective electrically conductive surface and ground.

15. The thermal control system of Claim 9, wherein the tube and the set of power systems form a heater subsystem, the fluid heating system further comprises a plurality of the heater subsystems and the plurality of the heater subsystems are electrically isolated from each other by way of the galvanically isolated power supplies.

Images