KR20220127170A - Heater bundles for thermal gradient compensation - Google Patents

Abstract

A heater bundle comprises: a plurality of heater assembling bodies. At least one among the heater assembling bodies includes a plurality of heater units. At least one among the heater units forms at least one heating section which is independently controlled. To compensate for uneven temperature inside the at least one heater unit, thermal provision is configured to modify thermal conductivity along a length of the at least one heater assembling body. The heater bundle includes a power supplying device including a controlling device which is configured to control power in the heating section which is independently controlled through power conductors based on a temperature determined to provide desired output along the length of the at least one heater assembling body.

Description

HEATER BUNDLES FOR THERMAL GRADIENT COMPENSATION

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Application Serial No. 15/058,838, filed March 2, 2016, and now U.S. Patent No. 10,247,445, entitled “Heater Bundles for Adaptive Control,” filed on February 11, 2019. It is a continuation-in-part of US Application No. 16/272,668. The contents of the above disclosures are incorporated herein by reference in their entirety.

The present disclosure relates to electric heaters, and more particularly to heaters for heating a fluid, such as a fluid inside a heat exchanger.

The description in this section merely provides background information related to the present disclosure and may not constitute prior art.

The fluid heater may be in the form of a cartridge heater, which has a rod configuration for heating fluid flowing along or past an outer surface of the cartridge heater. A cartridge heater may be disposed within the heat exchanger to heat a fluid flowing through the heat exchanger. If the cartridge heater is not properly sealed, moisture and fluid can enter the cartridge heater and contaminate the insulating material that electrically insulates the resistive heating element from the metal sheath of the cartridge heater, resulting in dielectric breakdown and consequent heater failure. Moisture can also cause short circuits between the power conductors and the outer metal sheath. Failure of the cartridge heater can stop the device using the cartridge heater, and the downtime is costly.

This section provides a general summary of the disclosure and is not an exhaustive disclosure of its full scope or all of its features.

The present disclosure provides a heater system comprising a heater bundle, the heater bundle comprising a plurality of heater assemblies, at least one of the heater assemblies comprising a plurality of heater units, and at least one heater The unit is an independently controlled heating zone. At least one thermal provision is configured to modify the thermal conductivity along the length of the at least one heater assembly to compensate for temperature non-uniformity. A plurality of power conductors are electrically connected to the heater units, and means for determining a temperature are provided. The power supply includes a controller configured to regulate power to an independently controlled heating zone via the power conductors based on a temperature determined to provide a desired power output along a length of the at least one heater assembly.

In variants of this heater system, which may be implemented individually or in any combination: the at least one heater unit is an end heater unit disposed at an end of the at least one heater assembly; the thermal means increase thermal conductivity within the at least one heater unit; the at least one thermal means comprises a conductive sleeve proximate to the resistive heating element of the at least one heater unit, the conductive sleeve having a higher thermal conductivity than a thermal conductivity of a material surrounding the resistive heating element; each of said heater units comprises an outer sheath, said at least one thermal means comprising at least one heater unit having an outer sheath having a greater thickness than adjacent heater unit outer sheaths; each of the heater units comprises an outer sheath, wherein the at least one thermal means comprises at least one heater unit having an outer sheath having a higher thermal conductivity than adjacent heater unit outer sheaths; the at least one thermal means comprises at least two power conductors operatively connected to the at least one heater unit, at least one of the two power conductors having a greater thickness in proximity to the at least one heater unit with; the at least one thermal means comprises at least two power conductors operatively connected to the at least one heater unit, at least one of the two power conductors having a higher thermal conductivity in proximity to the at least one heater unit with; said at least one thermal means comprises a length of said at least one heater unit that is shorter than a length of adjacent heater units; said at least one heater assembly defining spacings between adjacent heater units, said at least one thermal means comprising at least one of said spacings different between heater units; spacers are disposed between adjacent heater units, said at least one thermal means comprising a spacer between said at least one heater unit and adjacent heater units that is thicker than other spacers; said at least one thermal means comprising a plurality of power conductors having a cross-sectional area between adjacent heater units less than a nominal cross-sectional area; the at least one heater assembly includes resistive heating elements, wherein at least one of the resistive heating elements functions as a sensor; More than one of the heater units defines at least one independently controlled heating zone.

In another aspect of the present disclosure, a heater system includes a heater bundle, the heater bundle comprising: a plurality of heater assemblies, wherein at least one of the plurality of heater assemblies includes a plurality of heater units, and at least one heater unit is an independently controlled heating zone; a plurality of heater assemblies; at least one thermal provision configured to modify thermal conductivity along a length of the at least one heater assembly to compensate for temperature non-uniformity; and a plurality of power conductors electrically connected to the plurality of heater units. Means are provided for determining at least one of heating conditions and heating requirements, wherein the power supply is heated to provide a desired power output along a length of the at least one heater assembly. and a controller configured to regulate power to an independently controlled heating zone via the power conductors based on at least one of conditions and heating requirements.

In variants of this heater system, which may be implemented individually or in any combination: the at least one heater unit is an end heater unit disposed at an end of the at least one heater assembly; the thermal means increase thermal conductivity within the at least one heater unit; At least one of heating conditions and heating requirements is: a lifetime of the heater units, a reliability of the heater units, a size of the heater units, a cost of the heater units, a local local heater flux, the heater unit their characteristics and operation, and total power output; More than one of the heater units defines at least one independently controlled heating zone.

In another aspect, there is provided a heater assembly comprising a plurality of heater units, wherein at least one heater unit is an independently controlled heating zone; at least one thermal provision configured to modify thermal conductivity along a length of the heater assembly to compensate for temperature non-uniformity; a plurality of power conductors electrically connected to the plurality of heater units; and a controller configured to regulate power to an independently controlled heating zone via the power conductors based on at least one of heating conditions and heating requirements to provide a desired power output along the length of the heater assembly. A heater system including a power supply device is provided.

In variants of this heater system, which may be implemented individually or in any combination: the at least one heater unit is an end heater unit disposed at an end of the heater assembly; means for determining the temperature are provided; means are provided for determining heating conditions and heating requirements; more than one of the heater units defines at least one independently controlled heating zone; The at least one heater assembly includes resistive heating elements, wherein at least one of the resistive heating elements functions as a sensor.

In yet another variation, the heater system is included in a fluid heating device. The apparatus includes a sealed housing defining an interior chamber and having a fluid inlet and a fluid outlet, and a heater assembly disposed within the interior chamber of the housing. The heater assembly is configured to provide a responsive heat distribution to the fluid within the housing. The heat distribution is responsive based on the implementation of the thermal means, as shown and described herein.

Additional areas of applicability will become apparent from the description provided herein. It is to be understood that the description and specific examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure.

In order that the present disclosure may be better understood, various forms, given by way of example, will now be described with reference to the accompanying drawings.
1 is a perspective view of a heater bundle constructed in accordance with the teachings of the present disclosure;
2 is a perspective view of a heater assembly of the heater bundle of FIG. 1 in accordance with the teachings of the present disclosure;
3 is a perspective view of a variant of the heater assembly of the heater bundle of FIG. 1 in accordance with the teachings of the present disclosure;
FIG. 4 is a perspective view of the heater assembly of FIG. 3 in accordance with the teachings of the present disclosure, with the outer covering of the heater assembly removed for clarity;
5 is a perspective view of the core body of the heater assembly of FIG. 3 in accordance with the teachings of the present disclosure;
6 is a perspective view of a heat exchanger including the heater bundle of FIG. 1 in accordance with the teachings of the present disclosure, wherein the heater bundle is partially disassembled from the heat exchanger to expose the heater bundle for illustration purposes;
7 is a block diagram of a method of operating a heater system including a heater bundle constructed in accordance with the teachings of the present disclosure;
8 is a perspective view of a heater assembly including thermal means in accordance with the teachings of the present disclosure;
9 is a cross-sectional view of a heater assembly along lines 9-9 of FIG. 8, in accordance with the teachings of this disclosure;
10 is a cross-sectional view of a heater assembly along line 10-10 of FIG. 8, in accordance with the teachings of this disclosure;
11 is a perspective view of a heater assembly including another thermal means in accordance with the teachings of the present disclosure;
12 is a cross-sectional view of a heater assembly along line 12-12 of FIG. 11 in accordance with the teachings of this disclosure;
13 is a cross-sectional view of a heater assembly along line 13-13 of FIG. 11 in accordance with the teachings of the present disclosure;
14 is a perspective view of a heater assembly including another thermal means in accordance with the teachings of the present disclosure;
15 is a side view of a thermal means of the heater assembly of FIG. 14 in accordance with the teachings of the present disclosure;
16 is a perspective view of a heater assembly including thermal means in accordance with the teachings of the present disclosure;
17 is a perspective view of a heater assembly including thermal means in accordance with the teachings of the present disclosure;
18 is a cross-sectional view of a heater assembly along lines 18-18 of FIG. 17, in accordance with the teachings of this disclosure;
19 is a cross-sectional view of a heater assembly along line 19-19 of FIG. 17, in accordance with the teachings of this disclosure;
20 is a perspective view of a heater assembly including thermal means in accordance with the teachings of the present disclosure.
The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way.

The following description is merely illustrative in nature and is not intended to limit the disclosure, application or use of the present disclosure.

1 , a heater system constructed in accordance with the teachings of this disclosure is indicated generally by reference numeral 10 . The heater system 10 includes a heater bundle 12 and a power supply 14 electrically connected to the heater bundle 12 . The power supply 14 includes a controller 15 for controlling the power supply to the heater bundle 12 . “Heater bundle”, as used in this disclosure, refers to a heater device comprising two or more physically distinct heating devices that can be controlled independently. Thus, when one of the heating devices in the heater bundle fails or deteriorates, the remaining heating devices in the heater bundle 12 can continue to operate.

In one form, the heater bundle 12 includes a mounting flange 16 and a plurality of heater assemblies 18 secured to the mounting flange 16 . The mounting flange 16 includes a plurality of openings 20 through which the heater assemblies 18 extend. Although the heater assemblies 18 are arranged parallel in this configuration, it should be understood that alternative positions/dispositions of the heater assemblies 18 are within the scope of the present disclosure.

As further shown, the mounting flange 16 includes a plurality of mounting holes 22 . By using screws or bolts (not shown) through the mounting holes 22, the mounting flange 16 can be assembled to the wall of a vessel or pipe (not shown) carrying the fluid to be heated. At least a portion of the heater assemblies 18 is immersed in a fluid within a vessel or pipe to heat the fluid in this form of the present disclosure.

Referring to FIG. 2 , the heater assemblies 18 according to one form may be in the form of a cartridge heater 30 . The cartridge heater 30 generally includes a core body 32, a resistive heating wire 34 wound around the core body 32, and a metal sheath surrounding the core body 32 and the resistive heating wire 34 ( 36 ), and insulation filled in the space within the metal sheath 36 to insulate the resistive heating wire 34 from the metal sheath 36 and conduct heat from the resistive heating wire 34 to the metal sheath 36 . A tube-shaped heater comprising material 38 . The core body 32 may be made of ceramic. The insulating material 38 may be compressed magnesium oxide (MgO). A plurality of power conductors 42 extend through the core body 32 along the longitudinal direction and are electrically connected to the resistive heating wire 34 . The power conductors 42 also extend through an end piece 44 sealing the metal sheath 36 . The power conductors 42 are connected to a power supply 14 (shown in FIG. 1 ) to provide power from the power supply 14 to the resistive heating wire 34 . Although FIG. 2 tightens only two power conductors 42 extending through the end piece 44 , more than two power conductors 42 may extend through the end piece 44 . The power conductors 42 may be in the form of conductive pins. Various configurations of cartridge heaters and additional structural and electrical details are set forth in greater detail in US Pat. Nos. 2,831,951 and 3,970,822, which are jointly incorporated herein by reference, the contents of which are incorporated herein by reference in their entirety. incorporated by reference. Accordingly, the forms shown herein are illustrative only and should not be construed as limiting the scope of the present disclosure.

Alternatively, multiple pairs of resistive heating wires 34 and multiple power conductors 42 can be used to form multiple heating circuits that can be independently controlled to improve the reliability of cartridge heater 30 . have. Thus, when one of the resistive heating wires 34 fails, the remaining resistive heating wires 34 continue to heat without causing failure of the entire cartridge heater 30 and costly machine downtime. can cause

3 to 5 , the heater assemblies 50 may be in the form of a cartridge heater having a configuration similar to that of FIG. 2 except for the number of core bodies and the number of power conductors used.

More specifically, each of the heater assemblies 50 has an outer metal sheath 54 surrounding the plurality of heater units 52 together with the plurality of heater units 52 and the plurality of power conductors 56 . include An insulating material (not shown in FIGS. 3-5 ) is provided between the plurality of heater units 52 and the outer metal sheath 54 to electrically insulate the heater units 52 from the outer metal sheath 54 . . The plurality of heater units 52 each include a core body 58 and a resistive heating element 60 surrounding the core body 58 . The resistive heating element 60 of each heater unit 52 may form one or more heating circuits to form one or more heating zones 62 .

In this form, each heater unit 52 forms one heating zone 62 and a plurality of heater units 52 in each heater assembly 50 are aligned along the longitudinal direction X. Thus, each heater assembly 50 defines a plurality of heating zones 62 aligned along the longitudinal direction X. The core body 58 of each heater unit 52 defines a plurality of through holes/openings 64 through which the power conductors 56 extend. The resistive heating elements 60 of the heater units 52 are connected to power conductors 56 , which in turn are connected to a power supply 14 . The power conductors 56 supply power from the power supply 14 to the plurality of heater units 52 . By properly connecting the power conductors 56 to the resistive heating elements 60 , the resistive heating elements 60 of the plurality of heater units 52 are connected to the controller 15 of the power supply 14 . can be independently controlled by As such, failure of one resistive heating element 60 for a particular heating zone 62 will not affect the proper functioning of the remaining resistive heating elements 60 for the other heating zones 62 . In addition, the heater units 52 and the heater assemblies 50 may be interchangeable for ease of maintenance or assembly.

In this form, six power conductors 56 are used in each heater assembly 50 to power five independent electrical heating circuits on the five heater units 52 . Alternatively, the six power conductors 56 may be connected to the resistive heating elements 60 in a manner that forms three completely independent circuits in the five heater units 52 . It may have any number of power conductors 56 to form any number of independently controlled heating circuits and independently controlled heating zones 62 . For example, seven power conductors 56 may be used to provide six heating zones 62 . Eight power conductors 56 may be used to provide seven heating zones 62 .

The power conductors 56 may include a plurality of power supply and power return conductors, a plurality of power return conductors and a single power supply conductor, or a plurality of power supply conductors and a single power return conductor. When the number of heating zones is n, the number of power supply and return conductors is n+1.

Alternatively, a greater number of electrically distinct heating zones via multiplexing, polarity sensitive switching, and other circuit topologies by the controller 15 of the power supply 14 Fields 62 may be created. Thermal arrays ( The use of various arrangements or multiplexing of thermal arrays is disclosed in US Pat. Nos. 9,123,755, 9,123,756, 9,177,840, 9,196,513, and related applications thereof, which are jointly incorporated herein by reference. Their contents are hereby incorporated by reference in their entirety.

With this structure, each heater assembly 50 includes a plurality of heating zones 62 that can be independently controlled to vary the power output or heat distribution along the length of the heater assembly 50 . The heater bundle 12 includes a plurality of such heater assemblies 50 . Accordingly, the heater bundle 12 provides a plurality of heating zones 62 for heating the fluid flowing through the heater bundle 12 and a tailored heat distribution to be tailored to specific applications. The power supply 14 may be configured to regulate power to each of the independently controlled heating zones 62 .

For example, the heater assembly 50 may define “m” heating zones, and the heater bundle may include “k” heater assemblies 50 . Thus, the heater bundle 12 can form m*k heating zones. The plurality of heating zones 62 in the heater bundle 12 are based on the lifetime and reliability of the individual heater units 52 , the size and cost of the heater units 52 , the local heater flux, and the heater units 52 . ) can be individually and dynamically controlled in response to heating conditions and/or heating requirements including, but not limited to, characteristics and operation, and overall power output.

Each circuit, or selected heating zone, is dependent on the power and/or temperature distribution of changes in system parameters (e.g., manufacturing variations/tolerances, changing environmental conditions, inlet temperature, inlet temperature distribution, flow rate, velocity distribution, fluid composition, individually controlled to a desired temperature or desired power level to adapt to changes in inlet flow conditions such as fluid heat capacity, etc.). More specifically, the heater units 52 may not generate the same heat output when operated at the same power level due to manufacturing variations and variations in the degree of heater deterioration over time. The heater units 52 may be independently controlled to adjust the heat output according to a desired heat distribution. The individual manufacturing tolerances of the heater system components and the heater system assembly tolerances increase according to the regulated power of the power supply, in other words, because the accuracy of heater control is high, the manufacturing tolerances of individual components may be tight or narrow. No need.

Each of the heater units 52 may include a temperature sensor (not shown) for measuring the temperature of the heater units 52 . When a hot spot is detected in the heater units 52 , the power supply device 14 controls the specific heater unit 52 where the hot spot is detected in order to avoid overheating or failure of the specific heater unit 52 . ) to reduce or cut off the power supplied to The global supply 14 may regulate the power supplied to the heater units 52 adjacent the deactivated heater unit 52 to compensate for the reduced heat output from the particular heater unit 52 .

The power supply 14 is configured to block or reduce the level of power delivered to any specific zone, and to increase power to heating zones adjacent to the specific heating zone that is deactivated and has reduced heat output; It may include multi-zone algorithms. By carefully adjusting the power to each heating zone, the overall reliability of the system can be improved. By detecting hot spots and controlling the power supply accordingly, the heater system 10 has improved safety.

A heater bundle 12 having multiple independently controlled heating zones 62 can achieve improved heating. For example, some circuits in the heater unit 52 may have a nominal (or “typical”) duty cycle of less than 100% (or line voltage being a fraction of the power to be generated by the applied heater). at an average power level). Lower duty cycles allow the use of larger diameter resistive heating wires, thereby improving reliability.

In general, smaller regions will employ finer wire sizes to achieve a given resistance. Variable power control allows larger wire sizes to be used and lower resistance values can be accommodated while protecting the heater from overload by a duty cycle limit related to the power dissipation capacity of the heater.

The use of a scaling factor may be related to the capacity of the heater units 52 or heating zone 62 . Multiple heating zones 62 allow more accurate determination and control of heater bundle 12 . The use of a specific coefficient factor for a particular heating circuit/zone will allow for a more aggressive (ie, higher) temperature (or power level) in almost all zones, which in turn will result in a smaller and more Leads to cheap design. Such counting factors and methods are disclosed in US Pat. No. 7,257,464, which is incorporated herein by reference, the contents of which are incorporated herein by reference in their entirety.

The sizes of the heating zones controlled by the individual circuits can be made the same or different to reduce the total number of zones needed to control the distribution of temperature or power with a desired accuracy.

Referring again to FIG. 1 , the heater assemblies 18 are shown as a single ended heater, ie, the conductive fin extends through only one longitudinal end of the heater assemblies 18 . The heater assembly 18 may extend through a mounting flange 16 or bulkhead (not shown) and is sealed to the flange 16 or bulkhead. As such, the heater assemblies 18 can be individually removed and replaced without removing the mounting flange 16 from the vessel or tube.

Alternatively, the heater assembly 18 may be a “double ended” heater. In a double-ended heater, the metal sheath is bent into a hairpin shape so that both longitudinal ends of the metal sheath pass through the flange or partition wall and are sealed to the flange or partition wall, and the power conductors pass through both longitudinal ends of the metal sheath. In this construction, the flange or septum needs to be removed from the housing or vessel before the individual heater assemblies 18 can be replaced.

Referring to FIG. 6 , the heater bundle 12 is integrated into the heat exchanger 70 . The heat exchanger 70 includes a sealed housing 72 defining an inner chamber (not shown), and a heater bundle 12 disposed within the inner chamber of the housing 72 . The sealed housing 72 includes a fluid inlet 76 and a fluid outlet 78 through which fluid is guided into and out of the inner chamber of the sealed housing 72 . The fluid is heated by a heater bundle 12 disposed within a sealed housing 72 . The heater bundle 12 may be arranged for cross-flow or flow parallel to its length.

The heater bundle 12 is connected to a power supply 14, which may include means for regulating power, such as switching means or a variable transformer, to regulate the power supplied to the individual zones. Power regulation may be performed as a function of time or based on the detected temperature of each heating zone.

The resistive heating wire can also function as a sensor that uses the resistance of the resistive wire to measure the temperature of the resistive wire and uses the same power conductors to transmit the temperature measurement information to the power supply 14 . The temperature sensing means for each zone will allow control of the temperature (up to the resolution of the individual zone) along the length of each heater assembly 18 in the heater bundle 12 . Accordingly, additional temperature sensing circuits and sensing means can be omitted, thereby reducing manufacturing cost. Direct measurement of heater circuit temperature is a clear advantage when trying to maximize heat flux within a given circuit while maintaining the desired level of reliability for the system, as it eliminates or minimizes many of the measurement errors associated with using separate sensors. The heating element temperature is the characteristic that has the greatest influence on heater reliability. The use of resistive elements to function as both a heater and a sensor is disclosed in US Pat. No. 7,196,295, which is incorporated herein by reference, the contents of which are incorporated herein by reference in their entirety.

Alternatively, the power conductors 56 of dissimilar metals may be made of dissimilar metals such that the power conductors 56 can create a thermocouple for measuring the temperature of the resistive heating elements. have. For example, the at least one set of power supply and power return conductors may include different materials such that a junction is formed between the different materials and the resistive heating element of the heater unit and the junction determines the temperature of the one or more zones. can be used to do so. The use of “integrated” and “very thermally coupled” sensing, eg the use of different metals for a heater, leads to the generation of a thermocouple-like signal. The use of integrated and coupled power conductors for temperature measurement is disclosed in US Application Serial No. 14/725,537, which is jointly incorporated herein by reference, the contents of which are incorporated herein by reference in their entirety. .

The controller 15 for regulating the power delivered to each zone may be a closed-loop automatic control system. The closed-loop automatic control system receives temperature feedback from each zone and automatically and dynamically controls the power supply to each zone, thereby providing each in the heater bundle 12 without continuous or frequent human monitoring and adjustment. Automatically and dynamically control power distribution and temperature along the length of the heater assembly 18 of

The heater units 52 disclosed herein may also be calibrated using a variety of methods including, but not limited to, energizing and sampling each heater unit 52 to calculate its resistance. The calculated resistance may then be compared to the calibrated resistance to determine a resistance ratio, or compared to a value to determine the actual heater unit temperature. Exemplary methods are disclosed in US Pat. Nos. 5,280,422 and 5,552,998, which are incorporated herein by reference, the contents of which are incorporated herein by reference in their entirety.

One form of calibration is to operate the heater system 10 in at least one mode of operation, the heater system 10 to produce a desired temperature for at least one of the independently controlled heating zones 62 . control, collecting and recording data for at least one independently controlled heating zone 62 for the mode of operation, then for a heating system having a reduced number of independently controlled heating zones accessing recorded data to determine operating specifications, then using a heating system with a reduced number of independently controlled heating zones. The data may include, for example, power level and/or temperature information, among other operational data from the heater system 10 for which the data was collected and recorded.

In variations of the present disclosure, the heater system may include a single heater assembly 18 , rather than a plurality of heater assemblies in a heater bundle 12 . A single heater assembly 18 will include a plurality of heater units 52 , each heater unit 52 defining at least one independently controlled heating zone. Similarly, power conductors 56 are electrically connected to each of the independently controlled heating zones 62 within each heater unit 52 , and a power supply is provided via the power conductors 56 to each of the heater units. configured to regulate power to each of the independently controlled heating zones 62 .

Referring to FIG. 7 , a method 100 of controlling a heater system includes, at step 102 , providing a heater bundle comprising a plurality of heater assemblies. Each heater assembly includes a plurality of heater units. Each heater unit defines at least one independently controlled heating circuit (and consequently a heating zone). In step 104 , power to each of the heater units is supplied via power conductors electrically connected to each of the independently controlled heating zones of each of the heater units. In step 106, the temperature inside each of the zones is detected. The temperature may be determined using a change in resistance of the resistive heating element of at least one of the heater units. The zone temperature can be initially determined by measuring the zone resistance (or by measuring the circuit voltage, if suitable materials are used).

The temperature values can be digitized. Signals may be passed to a microprocessor. In step 108 , the measured (detected) temperature values may be compared to a target (desired) temperature for each zone. In step 110 , in order to achieve target temperatures, the power supplied to each of the heater units may be adjusted based on the measured temperature.

Optionally, the method may further comprise using a scaling factor to adjust the modulation power. The coefficient factor may be a function of the heating capacity of each heating zone. The controller 15 controls (updating the system) to determine the amount of power to be provided to each zone (via duty cycle, phase angle firing, voltage modulation or similar techniques) until the next update. Algorithms potentially including mathematical models and/or coefficient factors of the dynamic behavior of the system (including knowledge of time). The desired power can be converted into a signal, which is sent to a switch or other power conditioning device to control the power output to the individual heating zones.

In this aspect, when at least one heating zone is turned off due to an abnormal condition, the remaining zones continue to provide the desired amount of power without failure. Power is regulated for the activated heating zone to provide a desired amount of power when an abnormal condition is detected in the at least one heating zone. When one or more heating zones are turned off according to the determined temperature, the remaining zones continue to provide the desired amount of power. Power is adjusted for each of the heating zones as a function of at least one of the received signals, the model, and as a function of time.

For safety or process control reasons, typical heaters are generally required to prevent a specific location of the heater from exceeding a given temperature due to undesired chemical or physical reactions (eg, combustion/ignition/oxidation, coke boiling, etc.) at that specific location. to operate below the maximum permissible temperature. Thus, this is generally accommodated by conservative heater designs (eg, large heaters with low power densities and with most of the surface area loaded at a much lower heat flux than is possible).

However, with the heater bundle of the present disclosure, it is possible to measure and limit the temperature at any location inside the heater to a resolution for the size of the individual heating zones. Hot spots large enough to affect the temperature of the individual circuit can be detected.

Because the temperature of the individual heating zones can be automatically adjusted and consequently limited, the dynamic and automatic limiting of the temperature within each zone ensures that this zone and all other zones are optimally controlled without the risk of exceeding the desired temperature limit in any zone. It will keep operating at the power/heat flux level. This provides an advantage in limiting temperature measurement accuracy over the current practice of clamping a separate thermocouple to the sheath of one of the elements in the bundle. The reduced margin and ability to regulate power to individual zones can be selectively applied to heating zones, individually, rather than to the entire heater assembly, thereby reducing the risk of exceeding a predetermined temperature limit. Reduce.

The characteristics of a cartridge heater can change over time. This time-varying nature would otherwise require the cartridge heater to be designed for a single selected (worse case) flow regime, so that the cartridge heater would not be suboptimal for other flow conditions. sub-optimum) will work.

However, by dynamic control of the power distribution for the entire bundle up to a core-sized resolution due to the multiple heating units provided in the heater assembly, optimized power distribution for various flow conditions can be achieved, which is typical of a cartridge In contrast to only one power distribution corresponding to only one flow state in the heater. Thus, the heater bundle of the present application allows for an increase in the total heat flux for all other flow conditions.

In addition, variable power control can increase the flexibility of heater design. Voltage can be decoupled (to a significant extent) from the resistance in the heater design, and the heaters can be designed to have the largest wire diameter that can be mounted to the heater. This allows for increased power dissipation capacity for a given heater size and reliability level (or heater life), and allows the size of the bundle to be reduced for a given overall power level. In this configuration, power may be regulated by variable duty cycle, which is part of variable wattage controllers currently available or in development. The heater bundle may be protected by a programmable (or pre-programmed, if desired) limit on the duty cycle for a given zone to prevent "overload" of the heater bundle.

Referring to FIG. 8 , a perspective view of a heater assembly 50 with thermal provision is shown. Generally, the thermal means is configured to modify the thermal conductance along the length of the at least one heater assembly to compensate for the non-uniform temperature. Non-uniform temperatures may be within at least one heater unit, for example an end heater unit as described below. Alternatively, the non-uniform temperature may be between adjacent heater units of the heater assembly. This thermal means may take a variety of forms, which are presented in greater detail below, and may be embodied in one or more of the heater units.

As described above, the heater assemblies 50 each include a plurality of heater units 52 . Each heater unit 52 forms an end heater unit 52-1 and one of adjacent heater units 52-2. 9-10, each of the heater units 52-2 adjacent to the end heater units 52-1 includes a core body 58 and resistive heating surrounding the core body 58. element 60 . The resistive heating element 60 of each end heater unit 52-1 defines one or more end heating zones 62-1, the resistive heating element 60 of each adjacent heater unit 52-2. forms one or more adjacent heating zones 62-2. The end heater units 52-1 and the resistive heating elements 60 of adjacent heater units 52-2 are connected to power conductors 56, which in turn are connected to a power supply 14. do. The power conductors 56 supply power from the power supply 14 to the end heater units 52-1 and adjacent heater units 52-2. By selectively connecting the power conductors 56 to the resistive heating elements 60 , the resistive heating elements 60 of the end heater units 52-1 and adjacent heater units 52-2 are powered It can be independently controlled by the controller 15 of the supply device 14 .

In one form, the thermal means of the heater assembly 50 is implemented by a conductive sleeve 120 . As an example, referring to FIG. 10 , the conductive sleeve 120 is disposed proximate the resistive heating element 60 of the end heater unit 52-1. In one form, the conductive sleeve 120 surrounds the resistive heating element 60 and the core body 58 , the conductive sleeve 120 being disposed between the outer metal sheath 54 and the resistive heating element 60 . do. It should be understood that the conductive sleeve 120 may not completely enclose the resistive heating element 60 and the core body 58 in other configurations. It should also be understood that the conductive sleeve 120 may not be disposed between the resistive heating element 60 and the outer metal sheath 54 in other configurations.

In one form, the conductive sleeve 120 has a thermal conductivity greater than that of the outer metal sheath 54 . Accordingly, the conductive sleeve 120 is configured to increase the conductivity of the end heater unit 52-1 relative to adjacent heater units 52-2, thereby resulting in an undesirable temperature along the heater assembly 50. Suppress the gradient.

Referring to FIG. 11 , a perspective view of a heater assembly 50 with another exemplary thermal means is shown. In one form, the thermal means of the heater assembly 50 is implemented by an outer sheathing thermal means 130 . More specifically, referring to FIGS. 12-13 , the heater assembly 50 includes end outer metallic sheaths 54-1 and adjacent outer metallic sheaths 54-2, respectively. The end outer metal sheaths 54 - 1 and adjacent outer metal sheaths 54 - 2 collectively form an outer metal sheath 54 , wherein the outer sheath thermal means 130 is, in one form, external to the end. It is implemented by metal sheaths 54-1. However, it should be understood that the outer covering thermal means 130 may be implemented by any heater unit, and thus is not limited to the end heater units 52-1.

In one form, the end outer metal sheaths 54 - 1 and adjacent outer metal sheaths 54 - 2 have different thicknesses and/or thermal conductivity. As an example, the end outer metallization 54-1 has greater thicknesses and higher thermal conductivity compared to the adjacent outer metallization 54-2. Thus, the outer end metal sheath 54-1 increases the conductivity of the end heater unit 52-1 relative to the adjacent heater units 52-2, thereby causing an undesirable temperature along the heater assembly 50. configured to suppress the gradient. The end outer metallization 54-1 and adjacent outer metallization 54-2 may have varying thicknesses and/or thermal conductivities in different variations to selectively control the thermal gradient along the heater assembly 50. can

Referring to FIG. 14 , a perspective view of a heater assembly 50 with another exemplary thermal means is shown. In this form, the thermal means of the heater assembly 50 are implemented by the power conductor thermal means 140 . The power conductor thermal means 140 includes power conductors 56-1 (which may be at the end as shown in one form, or at any other location along the heater assembly 50) and It is implemented by adjacent power conductors 56 - 2 . In one form, the power conductors 56 - 1 and adjacent power conductors 56 - 2 collectively form a plurality of power conductors 56 . The power conductors 56-1 are connected to the resistive heating elements 60 of the end heater units 52-1, and the adjacent power conductors 56-2 are connected to the adjacent heater units 52-2. connected to the resistive heating elements 60 of

In some forms, referring to FIGS. 14-15 , power conductors 56-1 and adjacent power conductors 56-2 have different thicknesses, cross-sectional areas, and/or thermal conductivity. For example, the power conductors 56-1 have a thickness T1 that is greater than the thickness T2 and cross-sectional area of the adjacent power conductors 56-2 (which is proportional to the thickness T2 in this form). and a cross-sectional area, which in this form is proportional to the thickness T1. Accordingly, the power conductors 56 - 1 are configured to increase the conductivity of the end heater unit 52-1 relative to adjacent heater units 52 - 2 , thereby advantageously along the heater assembly 50 . Suppresses undesirable temperature gradients. The end power conductors 56 - 1 and adjacent power conductors 56 - 2 have varying thicknesses, cross-sectional areas and/or thermal conductivity in different forms to selectively control a thermal gradient along the heater assembly 50 . You have to understand that you can have them.

Referring to FIG. 16 , a perspective view of a heater assembly 50 with another exemplary thermal means is shown. In one form, the heater assembly 50 includes gaps 150 and adjacent gaps 152 , wherein the thermal means of the heater assembly 50 includes the gaps 150 (which is shown in one form). may be at the end as shown, or at any other location along the heater assembly 50). As used herein, “spacing” refers to the gap between successive heater units 52 . As an example, the gap 150 refers to gaps between the end heater units 52-1 and the adjacent heater unit 52-2, and the adjacent gaps 152 are the adjacent heater units 52-2. gaps between them. In one form, the width W1 of the end gaps 150 in the longitudinal direction X is greater than the width of the adjacent gaps 152 ( W2 ) in the longitudinal direction X .

On the other hand, although the width W1 of the gaps 150 shown in FIG. 16 is the same, it should be understood that the width W1 of the gaps 150 may not be the same in other forms. Likewise, while the width W2 of adjacent spacings 152 shown in FIG. 16 is the same, it should be understood that the width W2 of adjacent spacings 152 may not be the same in other configurations. In one form, the width W1 of the end gaps 150 is less than or equal to the width W2 of the adjacent gaps 152 . By selectively specifying the width W1 of the gaps 150 and the width W2 of the adjacent gaps 152, the end heater units 52-1 ( Alternatively, the conductivity of any other heater unit along the length of the heater assembly 50 may be increased to suppress undesirable temperature gradients along the length of the heater assembly 50 .

Referring to FIG. 17 , a perspective view of a heater assembly 50 with another exemplary thermal means is shown. In some forms, the heater assembly 50 has spacers 160 (which may be at the ends as shown in one form, or may be at any other location along the heater assembly 50 ). ) and adjacent spacers 162 , and the thermal means of the heater assembly 50 is implemented by the spacers 160 . The spacers 160 are disposed between the end heater unit 52-1 and the adjacent heater unit 52-2, and the adjacent spacers 162 are disposed between the adjacent heater units 52-2. The spacers 160 and adjacent spacers 162 have a low thermal conductivity, such as a ceramic material (eg, aluminum nitride, boron nitride, polyurethane, and a glass-based material such as borosilicate glass, acrylic glass, fiberglass, etc.). It can be implemented by various materials with

In some aspects, the width W3 of the spacers 160 in the longitudinal direction X is greater than the width W4 of the adjacent spacers 162 in the longitudinal direction X. Meanwhile, it should be understood that although the width W3 of the spacers 160 shown in FIG. 17 is the same, the width W3 of the spacers 160 may not be the same in other shapes. In one embodiment, the width W3 of the spacers 160 is less than or equal to the width W4 of the adjacent spacers 162 . By selectively specifying the width W3 of the spacers 160 and the width W4 of adjacent spacers 162 , the end heater unit 52-1 or any other along the length of the heater assembly 50 . The conductivity of the heater unit may be increased relative to adjacent heater units 52 - 2 to suppress undesirable temperature gradients along the heater assembly 50 .

In one form, the power conductor thermal means 140 and the spacers 160 described above with respect to FIGS. 14-15 are combined to collectively form a thermal means. As an example, as shown in FIGS. 18-19 , the power conductors 56-1 are placed inside the spacer 160 to which the power conductors 56-1 correspond and the corresponding end heater unit 52-1. It extends along the heater assembly 50 in the longitudinal direction (X) to be disposed therein (not shown). Similarly, adjacent power conductors 56-2 are arranged such that adjacent power conductors 56-2 are disposed inside a corresponding adjacent spacer 162 and inside a corresponding adjacent heater unit 52-2 (not shown). It extends along the heater assembly 50 in the longitudinal direction (X). In some forms, power conductors 56 - 1 disposed inside spacer 160 have a greater cross-sectional area than adjacent power conductors 56 - 2 disposed inside adjacent spacers 162 . The power conductors 56-1 disposed inside the spacer 160 may have a cross-sectional area that is less than or equal to the cross-sectional area of the adjacent power conductors 56-2 disposed inside the adjacent spacers 162 in other forms. You have to understand that you can.

Referring to FIG. 20 , a perspective view of a heater assembly 50 with another exemplary thermal means is shown. In one form, the thermal means of the heater assembly 50 is implemented by a variable width thermal means 170 . The variable width thermal means 170 includes at least one of the end heater units 52-1 (or any other heater unit along the length of the heater assembly 50). In some forms, the width W5 of the end heater units 52-1 in the longitudinal direction X is greater than the width W6 of the adjacent heater units 52-2 in the longitudinal direction X. It should be understood that in other forms, the width W5 of the end heater units 52-1 may be less than or equal to the width W6 of the adjacent heater units 52-2. By selectively specifying the width W5 of the end heater units 52-1 and the width W6 of the adjacent heater units 52-2, the end heater units compared to the adjacent heater units 52-2 The conductivity of 52-1 may be increased to suppress undesirable temperature gradients along the heater assembly 50 . Although not shown, it should be readily understood that the power conductors for the heater units 52 extend between the end heater units 52-1 through adjacent heater units 52-2.

8-20 , the controller 15 is configured to end based on a predefined model (eg, a mathematical model representing the various components and/or dynamic behaviors of the heater system 10 ) and at least one input. configured to calculate the temperature inside the heater units 52-1. In one form, the at least one input is a temperature at another location within the heater bundle 12 , an average temperature of the heater unit 52 , one of independently controlled heating zones 62 located in the heater assembly 18 . average temperature of any one, power consumption of any one of heater bundle 12 and/or heater units 52 , and/or power consumption of any one of heater bundle 12 and/or heater units 52 . average power consumption over a predetermined time period of In one form, the at least one input is a voltage of any one of the heater bundle 12 and/or heater units 52 , the voltage of any one of the heater bundle 12 and/or heater units 52 . current, current leakage of the heater bundle 12 and/or any one of the heater units 52 , and/or the insulation resistance of the heater bundle 12 . To perform the functions described herein, the controller 15 may have one or more sensing to measure the power of one or more electrical circuits/components (eg, heater units 52 ) to obtain at least one input. circuits).

As an example, the controller 15 controls the temperature inside the end heater unit 52-1 by supplying an initially known current to the end heater unit 52-1 and measuring the voltage of the end heater unit 52-1. configured to calculate. The controller 15 then compares the measured voltage with a nominal voltage associated with a known current to identify voltage deviations and/or corresponding resistance deviations. Then, the controller 15 calculates the temperature of the end heater unit 52-1 based on the voltage deviation and/or the corresponding resistance deviation using the predefined model. As described above, the controller 15 then regulates the power to the independently controlled heating zones 62 via the power conductors 56 based on the temperature of the end heater unit 52-1. . To perform the functions described herein, the controller 15 includes one or more processors configured to execute instructions stored in a non-transitory computer-readable medium, such as random access memory (RAM) and/or read-only memory (ROM). do.

Unless expressly indicated otherwise herein, all numerical values representing mechanical/thermal properties, composition percentages, dimensions and/or tolerances, or other properties are referred to as “about” or “approximately” when describing the scope of the present disclosure. It should be understood as being modified by the word " Such modifications are desirable for a variety of reasons including industry practice, materials, manufacturing, and assembly tolerances, and testing capabilities. .

Spatial and functional relationships between elements include "connected", "interlocked", "coupled", "adjacent", "next to", "above", "above", "below", and "disposed". described using a variety of terms, including Unless explicitly stated as “direct,” when a relationship between first and second elements is described in the present disclosure, the relationship is a direct relationship between the first and second elements in which no other intermediate elements exist. relationship, and may also be an indirect relationship in which one or more intermediate elements exist (spatially or functionally) between the first element and the second element. As used herein, the phrase at least one of A, B, and C is to be construed to mean logical (A OR B OR C), using a non-exclusive logical OR, "at least one of A, B of at least one, and at least one of C."

The description of the present disclosure is merely exemplary in nature, and thus, modifications that do not depart from the gist of the present disclosure are intended to be within the scope of the present disclosure. Such modifications should not be considered as a departure from the spirit and scope of the present disclosure. In addition, various omissions, substitutions, combinations, and variations in the forms of the systems, apparatus, and methods described herein, such omissions, substitutions, combinations, and variations are not expressly described or shown in the drawings of this disclosure. Even if not, it may be made without departing from the spirit and scope of the present disclosure.

Claims (26)

A heater system comprising a heater bundle, means for determining a temperature, and a power supply, comprising:
The heater bundle includes:
a plurality of heater assemblies, wherein at least one of the plurality of heater assemblies comprises a plurality of heater units, wherein the at least one heater unit is an independently controlled heating zone;
at least one thermal provision configured to modify thermal conductivity along a length of the at least one heater assembly to compensate for temperature non-uniformity; and
a plurality of power conductors electrically connected to the plurality of heater units; and
wherein the power supply includes a controller configured to regulate power to an independently controlled heating zone via the power conductors based on a temperature determined to provide a desired power output along a length of the at least one heater assembly. , heater system. According to claim 1,
wherein the at least one heater unit is an end heater unit disposed at an end of the at least one heater assembly. According to claim 1,
and the thermal means increase thermal conductivity within the at least one heater unit. 4. The method of claim 3,
wherein the at least one thermal means comprises a conductive sleeve proximate to the resistive heating element of the at least one heater unit, the conductive sleeve having a higher thermal conductivity than a thermal conductivity of a material surrounding the resistive heating element. 4. The method of claim 3,
wherein each of the heater units comprises an outer sheath and the at least one thermal means comprises at least one heater unit having an outer sheath having a greater thickness than adjacent heater unit outer sheaths. . 4. The method of claim 3,
wherein each of the heater units comprises an outer sheath and the at least one thermal means comprises at least one heater unit having an outer sheath having a higher thermal conductivity than adjacent heater unit outer sheaths. 4. The method of claim 3,
the at least one thermal means comprises at least two power conductors operatively connected to the at least one heater unit, at least one of the two power conductors having a greater thickness in proximity to the at least one heater unit Eggplant, heater system. 4. The method of claim 3,
the at least one thermal means comprises at least two power conductors operatively connected to the at least one heater unit, at least one of the two power conductors having a higher thermal conductivity in proximity to the at least one heater unit Eggplant, heater system. 4. The method of claim 3,
and the at least one thermal means comprises a length of the at least one heater unit that is less than a length of adjacent heater units. According to claim 1,
wherein said at least one heater assembly defines spacings between adjacent heater units, said at least one thermal means comprising at least one of said spacings different between heater units. system. According to claim 1,
Spacers are disposed between adjacent heater units, and wherein the at least one thermal means comprises a spacer between the at least one heater unit and an adjacent heater unit that is thicker than other spacers. According to claim 1,
wherein the at least one thermal means comprises a plurality of power conductors having a smaller cross-sectional area between adjacent heater units than a nominal cross-sectional area. According to claim 1,
wherein the at least one heater assembly includes resistive heating elements, wherein at least one of the resistive heating elements functions as a sensor. According to claim 1,
wherein more than one of the heater units form at least one independently controlled heating zone. A heater system comprising a heater bundle, means for determining at least one of heating conditions and heating requirements, and a power supply;
The heater bundle includes:
a plurality of heater assemblies, wherein at least one of the plurality of heater assemblies comprises a plurality of heater units, wherein the at least one heater unit is an independently controlled heating zone;
at least one thermal provision configured to modify thermal conductivity along a length of the at least one heater assembly to compensate for temperature non-uniformity; and
a plurality of power conductors electrically connected to the plurality of heater units; and
The power supply is configured to provide power to a heating zone independently controlled via the power conductors based on at least one of heating conditions and heating requirements to provide a desired power output along the length of the at least one heater assembly. A heater system comprising a controller configured to regulate 16. The method of claim 15,
wherein the at least one heater unit is an end heater unit disposed at an end of the at least one heater assembly. 16. The method of claim 15,
and the thermal means increase thermal conductivity within the at least one heater unit. 16. The method of claim 15,
At least one of heating conditions and heating requirements is: a lifetime of the heater units, a reliability of the heater units, a size of the heater units, a cost of the heater units, a local local heater flux, the heater unit a heater system selected from the group consisting of their characteristics and operation, and total power output. 16. The method of claim 15,
wherein more than one of the heater units form at least one independently controlled heating zone. a heater assembly comprising a plurality of heater units, wherein at least one heater unit is an independently controlled heating zone;
at least one thermal provision configured to modify thermal conductivity along a length of the heater assembly to compensate for temperature non-uniformity;
a plurality of power conductors electrically connected to the plurality of heater units; and
power comprising a controller configured to regulate power to an independently controlled heating zone via the power conductors based on at least one of heating conditions and heating requirements to provide a desired power output along the length of the heater assembly. A heater system comprising a supply device. 21. The method of claim 20,
wherein the at least one heater unit is an end heater unit disposed at an end of the heater assembly. 21. The method of claim 20,
and means for determining the temperature. 21. The method of claim 20,
and means for determining heating conditions and heating requirements. 21. The method of claim 20,
wherein more than one of the heater units form at least one independently controlled heating zone. As a fluid heating device:
a sealed housing defining an inner chamber and having a fluid inlet and a fluid outlet; and
The heater system according to claim 20;
the heater assembly is disposed inside the inner chamber of the housing;
wherein the heater assembly is configured to provide a responsive heat distribution to the fluid within the housing. 21. The method of claim 20,
wherein the heater assembly includes resistive heating elements, wherein at least one of the resistive heating elements functions as a sensor.

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