KR20220127174A - Heater bundles having virtual sensing for thermal gradient compensation - Google Patents

Abstract

A system includes a heater bundle having at least one heater assembly with a plurality of heater units. At least one of the heater units defines at least one independently controlled heating zone, and a plurality of power conductors are electrically connected to the heater units. A power supply device includes a controller configured to modulate power to the at least one independently controlled heating zone through the power conductors. The controller is configured to calculate a temperature within the at least one heater unit based on a predefined model and at least one input. The controller modulates power to the at least one heater unit based on the calculated temperature.

Description

HEATER BUNDLES HAVING VIRTUAL SENSING FOR THERMAL GRADIENT COMPENSATION

Cross-referencing of related applications

This application is a continuation of U.S. Patent Application Serial No. 15/058,838 (now U.S. Patent No. 10,247,445; filed March 2, 2016), U.S. Patent Application Serial No. 16/272,668 (filed on February 11, 2019) ; Title: "Heater Bundle for Adaptive Control") is a continuation-in-part application. The contents of these disclosures are incorporated herein by reference in their entirety.

technical field

The present disclosure relates to an electric heater, and more particularly to a heater 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 correspond to 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 the 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 fluids can enter the cartridge heater and contaminate the insulating material that electrically insulates the resistive heating element from the cartridge heater's outer metal sheath, resulting in dielectric breakdown and As a result, it may cause heater failure. Moisture can also cause short circuiting between the power conductors and the outer metal sheath. Failure of the cartridge heater can result in costly downtime for devices using the cartridge heater.

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 having at least one heater assembly having a plurality of heater units, wherein at least one of the heater units is at least one independent Defines a controlled heating zone. A plurality of power conductors are electrically connected to the heater units, the power supply including a controller configured to modulate power supplied to the at least one independently controlled heating zone via the power conductors do. The controller is configured to calculate a temperature in the at least one heater unit based on the predefined model and the at least one input, and the controller adjusts power to supply to the at least one heater unit based on the calculated temperature.

In variants of the present heater system, these variants may be implemented with any combination or each of the following features: at least one heater unit is an end heater unit; at least one input includes a temperature at another location within the heater bundle; the at least one input includes a temperature of at least one of at least one of the plurality of heater units; the at least one input includes a power consumption of the heater bundle; the at least one input includes an average power consumption of the heater bundle over a predetermined period of time; the at least one input includes a voltage of the heater bundle and/or a voltage of at least one of the heater units; the at least one input comprises a current of the heater bundle and/or a current of at least one of the heater units; the at least one input includes a current leakage of the heater bundle; at least one input includes an insulation resistance of the heater bundle; the at least one input includes at least one of a fluid temperature, a fluid speed, a fluid velocity, and a fluid mass flow rate; The controller is configured to supply a known current to the plurality of heater units, measure a voltage in at least one independently controlled heating zone, and combine the measured voltage with a nominal current associated with the known known current. calculating the temperature by comparing the voltage to the nominal voltage to determine voltage deviations and/or corresponding resistance deviations; and the controller is configured to apply a known voltage to the plurality of heater units, measure a current in the at least one independently controlled heating zone, and compare the measured current to a nominal current associated with the known voltage. By determining the current deviation and/or the corresponding resistance deviation, the temperature is calculated.

In another variant of this heater system, the fluid heating device includes a sealed housing defining an inner chamber and defining a fluid inlet and a fluid outlet, and wherein the at least one heater assembly comprises an inner chamber of the housing. placed within The at least one heater assembly is adapted to provide a responsive heat distribution to the fluid within the housing. The heat distribution is “responsive” based on the implementation of virtual sensing as described herein.

In another aspect of the present disclosure, a heater system includes a heater assembly comprising a plurality of heater units, wherein at least one heater unit defines at least one independently controlled heating zone. The plurality of power conductors are electrically coupled to the heater units, and the power supply includes a controller configured to regulate power supplied via the power conductors to the at least one independently controlled heating zone. the controller is configured to calculate a temperature in the at least one heater unit based on the predefined model and the at least one input, and the controller adjusts, based on the calculated temperature, power supplied to the at least one heater unit do.

In variants of the present heater system, these variants may be implemented with any combination or each of the following features: at least one heater unit is an end heater unit; The controller is configured to supply a known current to the plurality of heater units, measure a voltage in the at least one independently controlled heating zone, and compare the measured voltage to a nominal voltage associated with the known current to generate a voltage calculating the temperature by ascertaining the deviation and/or the corresponding resistance deviation; and the controller is configured to apply a known voltage to the plurality of heater units, measure a current in the at least one independently controlled heating zone, and compare the measured current to a nominal current associated with the known voltage. By determining the current deviation and/or the corresponding resistance deviation, the temperature is calculated. Also, an apparatus having these variants of a heater system includes a sealed housing defining an interior chamber and having a fluid inlet and a fluid outlet. The heater assembly is disposed within an interior chamber of the housing and is adapted to provide a responsive heat distribution to a fluid within the housing.

In yet another aspect, a heater system includes a heater assembly comprising a plurality of heater units, more than one of the plurality of heater units defining at least one independently controlled heating zone. The plurality of power conductors are electrically connected to the heater units, and the power supply includes a controller configured to regulate power supplied through the power conductors to an independently controlled heating zone. the controller is configured to calculate a temperature within the one or more heater units based on the predefined model and the at least one input, and the controller adjusts the power supplied to the one or more heater units based on the calculated temperature. do.

In variants of the present heater system, these variants may be implemented with any combination of or each of the following features: the at least one heater unit is an end heater unit; The controller is configured to supply a known current to the plurality of heater units, measure a voltage in the at least one independently controlled heating zone, and compare the measured voltage to a nominal voltage associated with the known current to generate a voltage calculating the temperature by ascertaining the deviation and/or the corresponding resistance deviation; and the controller is configured to apply a known voltage to the plurality of heater units, measure a current in the at least one independently controlled heating zone, and compare the measured current to a nominal current associated with the known voltage. By determining the current deviation and/or the corresponding resistance deviation, the temperature is calculated.

Additional areas of applicability will become apparent from the description provided herein. As will be understood, 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, provided by way of illustration, will be described below 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;
4 is a perspective view of the heater assembly of FIG. 3 in accordance with the teachings of the present disclosure, wherein the outer sheath of the heater assembly has been omitted 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 comprising 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 illustrative 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 this disclosure.
8 is a perspective view of a heater assembly including a heat supply device in accordance with the teachings of this disclosure;
9 is a cross-sectional view of a heater assembly along line 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 heat supply in accordance with the teachings of this 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 taken along line 13-13 of FIG. 11, in accordance with the teachings of this disclosure;
14 is a perspective view of a heater assembly including another heat supply in accordance with the teachings of this disclosure;
15 is a side view of a heat supply device 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 a heat supply device in accordance with the teachings of this disclosure;
17 is a perspective view of a heater assembly including a heat supply device in accordance with the teachings of this 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 a heat supply device in accordance with the teachings of this 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 exemplary in nature and is not intended to limit the disclosure, application, or use.

Referring to FIG. 1 , a heater system constructed in accordance with the teachings of the present disclosure is generally indicated 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 . As used herein, “heater bundle” 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 of the heater bundle fails or deteriorates in performance, the remaining heating devices of 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 to be parallel in this configuration, it should be understood that alternative positions/arrangements 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 openings 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 the fluid within the 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 is a tube-shaped heater, and the tube-shaped heater is typically a core body 32, a resistive heating wire 34 wrapped around the core body 32, and a core body ( 32 ) and a metal sheath 36 surrounding the resistive heating wire 34 , and an insulator material 38 filling the space within the metal sheath 36 . It is electrically insulated from the sheath 36 and thermally conducts heat from the resistive heating wire 34 to the metal sheath 36 . The core body 32 may be made of ceramic. The insulating material 38 may be filled with 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 wires 34 . The power conductors 42 also extend through an end piece 44 that seals the metal sheath 36 . Power conductors 42 are connected to power supply 14 (shown in FIG. 1 ) for supplying power from power supply 14 to resistive heating wire 34 . 2 shows 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 constructions and additional structural and electrical details of cartridge heaters are described in greater detail in US Pat. Nos. 2,831,951 and 3,970,822, which are commonly assigned with this application and are incorporated herein by reference in their entirety. incorporated herein by Accordingly, the forms illustrated herein are merely examples 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 may be used to form multiple heating circuits that can be independently controlled to improve the reliability of cartridge heater 30 . can 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 includes a plurality of heater units 52 , and a metal sheath 54 surrounding the plurality of heater units 52 together with a plurality of power conductors 56 . do. An insulating material (not shown in FIGS. 3-5 ) is provided between the plurality of heater units 52 and the metal sheath 54 to electrically insulate the heater units 52 from the 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 define one or more heating circuits to define one or more heating zones 62 .

In this form, each heater unit 52 defines 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 the 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 controlled by the controller 15 of the power supply 14 . can be independently controlled. 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 . Further, 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 defining three completely independent circuits on the five heater units 52 . It is possible to 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 .

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.

Using 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 . Thus, the heater bundle 12 provides a tailored heat distribution for heating the fluid flowing through the plurality of heating zones 62 and the heater bundle 12, making it suitable for specific applications. The power supply 14 may be configured to regulate the power supplied 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 may define 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 the characteristics and operation of

Each circuit is capable of varying temperature and/or power distributions such as changes in system parameters (e.g., manufacturing variations/tolerances, changing environmental conditions, inlet temperature, inlet temperature distribution, flow rate, velocity distribution, fluid composition, fluid heat capacity, etc.) individually controlled to a desired temperature or desired power level to adapt to changes in inlet flow conditions). More particularly, the heater units 52 may not generate the same heat output when operated under the same power level due to manufacturing variations as well as varying degrees of heater degradation over time. Heater units 52 may be independently controlled to adjust heat output according to a desired heat distribution. The individual manufacturing tolerances of the components of the heater system and the assembly tolerances of the heater system increase as a function of the regulated power of the power supply. Or, in other words, since the fidelity of heater control is high, the manufacturing tolerances of individual components need not be tight or narrow.

The heater units 52 may each 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 supplies power to the specific heater unit 52 in which the hot spot is detected in order to avoid overheating or failure of the specific heater unit 52 . can be reduced or turned off. The power supply 14 modulates the power supplied to the heater unit 52 adjacent the disabled heater unit 52 to compensate for the reduced heat output from that particular heater unit 52 . )can do.

Power supply 14 is a multi-zone algorithm for turning off or lowering the level of power delivered to any specific zone and increasing the power supplied to heating zones adjacent to that specific heating zone that has been deactivated and has reduced heat output. (multi-zone algorithms). By carefully controlling the power supplied to each heating zone, the overall reliability of the system can be improved. By detecting the hot spot 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 of heater units 52 may have a nominal (or “typical”) duty cycle (or line voltage) of less than 100%. at an average power level that is a fraction of the power that would be generated by the heater in the applied state). Lower duty cycles allow resistive heating wires with larger diameters to be used, improving reliability.

Typically, smaller regions use finer wire sizes to achieve a given resistance. Variable power control allows the use of larger wire sizes, accommodates lower resistance values, and at the same time protects the heater from overload, using a duty cycle limit tied to the power dissipation capacity of the heater. can protect

The use of a scaling factor may be tied to the capacity of the heater units 52 or heating zone 62 . Multiple heating zones 62 allow more accurate measurement and control of heater bundle 12 . Using a specific scaling factor for a specific 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 less expensive heater bundle. (12) leads to the design. Such scaling factors and methods are disclosed in US Pat. No. 7,257,464, which is assigned in common with this application, the contents of which are incorporated herein by reference in their entirety.

The size 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 temperature or power distribution with the desired accuracy.

Referring again to FIG. 1 , the heater assemblies 18 are shown as a single end heater, ie, a conductive pin spans only one longitudinal end of the heater assemblies 18 . extended through The heater assembly 18 may extend through a mounting flange 16 or bulkhead (not shown) and may be sealed to the mounting flange 16 or bulkhead. Accordingly, 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 power conductors pass through the 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 a heat exchanger 70 . Heat exchanger 70 includes a sealed housing 72 defining an interior chamber (not shown), and a heater bundle 12 disposed within the interior chamber of 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 . do. The fluid is heated by a heater bundle 12 disposed in a sealed housing 72 . The heater bundle 12 may be arranged for cross-flow or flow parallel to the length of the bundle.

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 sensed temperature of each heating zone.

The resistive heating wire may function as a sensor that uses the resistance of the resistive wire to measure the temperature of the resistive wire and also transmits the temperature measurement information to the power supply 14 using the same power conductors. The means for sensing the temperature for each zone makes it possible to control the temperature (up to the resolution of the individual zones) along the length of each heater assembly 18 in the heater bundle 12 . Accordingly, an additional temperature sensing circuit and sensing means can be omitted, thereby reducing the manufacturing cost. Direct measurement of heater circuit temperature eliminates or minimizes many of the measurement errors associated with the use of separate sensors when attempting to maximize heat flux within a given circuit while maintaining the desired level of reliability for the system. a distinct advantage. Heating element temperature is the characteristic that has the greatest influence on heater reliability. U.S. Patent No. 7,196,295, which is assigned jointly with this application, the contents of which are incorporated herein by reference in their entirety, discloses the use of resistive elements to function as both heaters and sensors. .

Alternatively, the power conductors 56 may be made of dissimilar metals such that the power conductors 56 of dissimilar metals may form a thermocouple for measuring the temperature of the resistive heating elements. For example, the power supply and at least one set of the power return conductor may include different materials such that a junction is formed between the resistive heating element of the heater unit and another material to be used to measure the temperature of one or more zones. can Using "integrated" and "highly thermally coupled" sensing, for example using different metals for the heater, results in the generation of a thermocouple type signal. The use of integrated and coupled power conductors for temperature measurement is disclosed in US Application Serial No. 14/725,537, which is assigned jointly with this application, the contents of which are incorporated herein by reference in their entirety. have.

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, thus without continuous or frequent human monitoring and adjustment, the heater bundle (12). Automatically and dynamically control the power distribution and temperature along the length of each heater assembly 18 within.

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 with the calibrated resistance to determine a resistance ratio, or its value, and then the actual heater unit temperature. Exemplary methods are disclosed in US Pat. Nos. 5,280,422 and 5,552,998, which are assigned jointly with this application, the contents of which are incorporated herein by reference in their entirety.

One form of calibration includes the following steps: operating the heater system 10 in at least one operating mode; controlling the heater system (10) to generate a desired temperature for at least one of the independently controlled heating zones (62); collecting and recording data for the at least one independently controlled heating zones (62) for that mode of operation; then accessing the recorded data to determine operating specifications for a heating system having a reduced number of independently controlled heating zones; and, then using a heating system having the 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 having its data 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 within the 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 connects the heater units via the power conductors 56 . 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, in 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). Power to each of the heater units is supplied in step 104 via power conductors electrically connected to each of the independently controlled heating zones within each of the heater units. The temperature within each zone is sensed in step 106 . The temperature may be measured using a change in resistance of the resistive heating element of at least one of the heater units. The zone temperature can be measured initially by measuring the zone resistance (or by measuring the circuit voltage, if a suitable material is used).

The temperature value can be digitized. The signal may be communicated to the microprocessor. The measured (sensed) temperature value may be compared to a target (desired) temperature for each zone in step 108 . Power supplied to each of the heater units may be adjusted based on the measured temperature in step 110 to achieve a target temperature.

Optionally, the method may further comprise using a scaling factor to adjust the modulating power. The scaling factor may be a function of the heating capacity of each heating zone. The controller 15 is configured to measure the amount of power provided to each zone (via a duty cycle, phase angle firing, voltage modulation, or similar technique) until the next update. , possibly including scaling factors and/or mathematical models of the dynamic behavior of the system, including knowledge of the system's update times. 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 form, when at least one heating zone is turned off due to an anomalous condition, the remaining zones continue to provide the desired wattage without failure. When an abnormal condition is detected in the at least one heating zone, power is regulated into a functional heating zone to provide the desired wattage. When at least one heating zone is turned off based on the measured temperature, the remaining zones continue to provide the desired wattage. Power is conditioned into each of the heating zones as a function of at least one of the received signals, as a function of the model, and as a function of time.

For safety or process control reasons, typical heaters are typically operated below the maximum allowable temperature, thereby preventing unwanted chemical or physical reactions at certain locations, such as combustion/fire/oxidation, coking boiling, etc. Due to this, a specific location of the heater is prevented from exceeding a given temperature. Thus, this is typically the case with conservative heater designs (eg, large heaters with low power densities and having a large portion of the surface area receive a much lower heat flux than would otherwise be possible). is accepted by

However, using the heater bundles of the present disclosure, it is possible to measure and limit the temperature of any location within the heater to a resolution on the order of the size of the individual heating zones. A hot spot large enough to affect the temperature of an individual circuit can be detected.

Because the temperature of individual heating zones can be automatically adjusted and consequently limited, a dynamic and automatic limitation of the temperature within each zone is the desired temperature limit for this zone and all other zones, in any zone. It will maintain operation at optimum power/heat flux levels without fear of exceeding This provides an advantage in high-limit temperature measurement accuracy over the current practice of fixing a separate thermocouple to the sheath of one of the elements in the bundle. The ability to regulate power to individual zones, and reduced margin, does not apply to the entire heater assembly, but selectively and individually to the heating zones. ) can be applied, thereby reducing the risk of exceeding a predetermined temperature limit.

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, due to the multiple heating units provided in the heater assembly, dynamic control of the power distribution over the entire bundle up to a core-sized resolution can be achieved, so that an optimized power distribution for various flow conditions can be achieved, which is typical Contrary to the case of only one power distribution corresponding to only one flow state in a cartridge heater. Thus, the heater bundle of the present application enables an increase in the total heat flux for all different flow conditions.

In addition, variable power control can increase heater design flexibility. The voltage can be de-coupled from the resistance (to a large extent) in the heater design, and the heater can be designed to have the largest wire diameter that can be mounted within the heater. This allows for an increased capacity for power dissipation, for a given heater size and reliability level (or heater life), and for a given overall power level, for the bundle size to be reduced. The power in this arrangement can be regulated by a variable duty cycle that is part of a variable wattage controller currently available or under 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 "overloading" the heater bundle.

Referring to FIG. 8 , a perspective view of a heater assembly 50 with a thermal provision is shown. Typically, the heat supply device is configured to modify a thermal conductance along the length of the at least one heater assembly to compensate for a non-uniform temperature within the at least one heater unit. This heat supply can take a variety of forms, as described in more detail below.

As mentioned above, the heater assemblies 50 each include a plurality of heater units 52 . Each heater unit 52 defines an end heater unit 52-1 and one of adjacent heater units 52-2. 9 to 10 , each of the end heater units 52-1 and the adjacent heater units 52-2 is a core body 58 and a resistive heating element surrounding the core body 58 . (resistive heating element) 60 . The resistive heating element 60 of each end heater unit 52-1 defines one or more end heating zones 62-1, and the resistive heating element 60 of each adjacent heater unit 52-2 defines one or more adjacent heating zones 62-2.

End heater units 52-1 and resistive heating elements 60 of adjacent heater units 52-2 are connected to power conductors 56, which in turn are connected to power supply 14 do. Power conductors 56 supply power from power supply 14 to end heater units 52-1 and adjacent heater units 52-2. By selectively connecting power conductors 56 to resistive heating elements 60 , resistive heating elements 60 of end heater units 52-1 and adjacent heater units 52-2 are can be independently controlled by the controller 15 of the power supply 14 .

In one form, the heat supply 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 metal sheath 54 and the resistive heating element 60 . 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 forms. It should also be understood that the conductive sleeve 120 may not be disposed between the resistive heating element 60 and the metallic sheath 54 in other forms.

In one form, the conductive sleeve 120 has a thermal conductivity greater than that of the metallic 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 causing an undesirable temperature gradient along the heater assembly 50. suppress

Referring to FIG. 11 , a perspective view of a heater assembly set 50 having another exemplary heat supply is shown. In one form, the heat supply of the heater assembly 50 is implemented by an outer sheath thermal provision 130 . More particularly, and with reference to FIGS. 12-13 , the heater assembly 50 includes end outer metal sheaths 54 - 1 and adjacent metal sheaths 54 - 2 respectively. The end metal sheaths 54 - 1 and adjacent metal sheaths 54 - 2 collectively form a metal sheath 54 , and an outer sheath thermal provision 130 is provided with the end metal sheaths. (54-2).

In one form, end metal sheaths 54-1 and adjacent metal sheaths 54-2 have different thicknesses and/or thermal conductivity. As an example, the end metal sheath 54 - 1 has greater thicknesses and higher thermal conductivity compared to the adjacent metal sheath 54 - 2 . Thus, the 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 gradient along the heater assembly 50 . is configured to suppress It is noted that the end metal sheath 54-1 and the adjacent metal sheath 54-2 may have varying thicknesses and/or thermal conductivities in different variations to selectively control the thermal gradient along the heater assembly 50. should be understood

Referring to FIG. 14 , a perspective view of a heater assembly 50 with another exemplary heat supply is shown. In this form, the heat supply of the heater assembly 50 is implemented by a power conductor heat supply 140 . Power conductor heat supply 140 is implemented by end power conductors 56-1 and adjacent power conductors 56-2. In one form, end power conductors 56 - 1 and adjacent power conductors 56 - 2 collectively form a plurality of power conductors 56 . The end 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, with reference to FIGS. 14-15 , end power conductors 56 - 1 and adjacent power conductors 56 - 2 have different thicknesses, different cross-sectional areas, and/or different thermal conductivities. For example, the end power conductors 56-1 have a thickness greater than the thickness T ₂ and the cross-sectional area (which in this form is proportional to the thickness T ₂ ) of the adjacent power conductors 56-2 ( T ₁ ) and a cross-sectional area, which in this form is proportional to the thickness T ₁ . Accordingly, the end power conductors 56 - 1 are configured to increase the conductivity of the end heater unit 52-1 relative to the adjacent heater units 52 - 2 , thereby resulting in a desirable according to the heater assembly 50 . Suppresses undesirable temperature gradients. End power conductors 56 - 1 and adjacent power conductors 56 - 2 have varying thicknesses, cross-sectional areas, and in different forms to selectively control thermal gradients along heater assembly 50 . It should be understood that/or may have thermal conductivities.

Referring to FIG. 16 , a perspective view of a heater assembly 50 with another exemplary heat supply is shown. In one form, the heater assembly 50 includes end spacings 150 and adjacent spacings 152 , wherein the heat supply of the heater assembly 50 is defined by the end spacings 150 . do. As used herein, “spacing” refers to the gap between successive heater units 52 . As an example, the end gaps 150 refer to gaps between the end heater units 52-1 and the adjacent heater unit 52-2, and the adjacent gaps 152 refer to the adjacent heater units 52-2. ) between the gaps. In one form, the width W ₁ of the end gaps 150 in the longitudinal direction X is greater than the width of the adjacent gaps 152 (W ₂ ) in the longitudinal direction X .

Although the width W ₁ of the end gaps 150 shown in FIG. 16 is the same, it should be understood that the width W ₁ of the end gaps 150 may not be the same in other forms. Likewise, while the width W ₂ of adjacent gaps 152 shown in FIG. 15 is the same, it should be understood that the width W ₂ of adjacent gaps 152 may not be the same in other configurations. In one form, the width W ₁ of the end gaps 150 is less than or equal to the width W ₂ of the adjacent gaps 152 . By selectively designing the width W ₁ of the end gaps 150 and the width W ₂ of the adjacent gaps 152 , the end heater units ( 52 - 2 ) compared to the adjacent heater units ( 52 - 2 ). 52-1) 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 heat supply is shown. In some forms, the heater assembly 50 includes end spacers 160 and adjacent spacers 162 , and the heat supply of the heater assembly 50 is provided by the end spacers 160 . is implemented The end spacers 160 are disposed between the end heater units 52-1 and the adjacent heater unit 52-2, and the adjacent spacers 162 are disposed between the adjacent heater units 52-2. . End spacers 160 and adjacent spacers 162 may be formed of a ceramic material (eg, aluminum nitride, boron nitride, polyurethane, and a glass-based material such as borosilicate glass, acrylic glass, fiberglass, etc.) ) can be implemented by various materials with lower thermal conductivity.

In some forms, the width W ₃ of the spacers 160 in the longitudinal direction X is greater than the width W ₄ of the adjacent spacers 162 in the longitudinal direction X. Although the width W ₃ of the end spacers 160 shown in FIG. 17 is the same, it should be understood that the width W ₃ of the end spacers 160 may not be the same in other configurations. Likewise, while the width W ₄ of adjacent spacers 162 shown in FIG. 15 is the same, it should be understood that the width W ₄ of adjacent spacers 162 may not be the same in other configurations. In one form, the width W ₃ of the end spacers 160 is less than or equal to the width W ₄ of the adjacent spacers 162 . By selectively designing the width W ₃ of the end spacers 160 and the width W ₄ of the adjacent spacers 162 , the end heater units ( 52 - 2 ) compared to the adjacent heater units ( 52 - 2 ) 52-1) can be increased to suppress undesirable temperature gradients occurring along the length of the heater assembly 50.

In one form, the power conductor heat supply 140 described above with respect to FIGS. 14-15 , and the end spacers 160 are combined to collectively form a heat supply. As an example, as shown in FIGS. 18-19 , the end power conductors 56 - 1 may have end power conductors 56 - 1 inside a corresponding end spacer 160 and at a corresponding end It extends along the heater assembly 50 in the longitudinal direction X so as to be disposed inside the heater unit 52-1 (not shown). Similarly, adjacent power conductors 56 - 2 may be connected such that adjacent power conductors 56 - 2 are disposed within a corresponding adjacent spacer 162 and within a corresponding adjacent heater unit 52 - 2 (not shown). to extend along the heater assembly 50 in the longitudinal direction (X). In some forms, end power conductors 56 - 1 disposed inside end spacer 160 have a greater cross-sectional area than adjacent power conductors 56 - 2 disposed inside adjacent spacers 162 . As should be understood, the end power conductors 56 - 1 disposed inside the end spacer 160 , in other forms, the adjacent power conductors 56 - 2 disposed inside the adjacent spacers 162 . It may have a cross-sectional area that is less than or equal to the cross-sectional area of .

Referring to FIG. 20 , a perspective view of a heater assembly 50 with another exemplary heat supply is shown. In one form, the heat supply of the heater assembly 50 is implemented by a variable width heat supply 170 . The variable width heat supply 170 includes at least one of the end heater units 52-1. In some forms, the width W ₅ of the end heater units 52-1 in the longitudinal direction X is greater than the width W ₆ of adjacent heater units 52-2 in the longitudinal direction X. bigger As should be understood, in other forms, the width W ₅ of the end heater units 52-1 may be less than or equal to the width W ₆ of the adjacent heater units 52-2. . By selectively designing the width W ₅ of the end heater units 52-1 and the width W ₆ of the adjacent heater units 52-2, the adjacent heater units 52-2 In comparison, the conductivity of the end heater units 52-1 may be increased to suppress undesirable temperature gradients occurring along the heater assembly 50 . Although not shown, as should be readily understood, 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 includes a predefined model (eg, in particular a mathematical model representing the dynamic behavior and/or various components of the heater system 10 ) and at least one based on the input, it is configured to calculate a temperature within at least one of the heater units 52 , such as the end heater unit 52-1 (this conventional approach is a “virtual” approach because the temperature is calculated rather than measured. Also called "virtual sensing"). In one form, the at least one input includes a temperature at another location within the heater bundle 12 , a temperature of another heater unit 52 , independently controlled heating zones 62 disposed on the heater assembly 18 . the temperature of any one of the heater bundles 12 and/or the power consumption of any one of the heater units 52 , and/or the predetermined Includes, but is not limited to, average power consumption over a period of time. In one form, at least one input includes a voltage of any one of heater bundle 12 and/or heater units 52 , a voltage of any one of heater bundle 12 and/or heater units 52 . current, the amount of 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 , but are not limited thereto. To perform the function described herein, the controller 15 is configured to obtain at least one input, one or more electrical circuits/components (eg, one for measuring the power of the heater units 52 ). the above sensing circuits).

For example, the controller 15 may initially supply a known current to the heater units 52 and measure the voltage of the end heater unit 52-1, whereby the temperature in the end heater unit 52-1 is is configured to calculate The controller 15 then compares the measured voltage to a nominal voltage coupled 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, based on the temperature of the end heater unit 52-1 , supplies power to the independently controlled heating zones 62 via the power conductors 56 . adjust the To perform the functions described herein, the controller 15 is configured to execute one or more instructions stored in a non-transitory computer-readable medium, such as random access memory (RAM) and/or read-only memory (ROM). including processors. Alternatively, the controller 15 may perform the steps of supplying a known voltage to the plurality of heater units 52 , measuring a current in the at least one independently controlled reversible region 62 , and the measured current The temperature is calculated by comparing the s to the nominal current associated with a known voltage to determine the current deviation and/or the corresponding resistance deviation.

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

Spatial and functional relationships between elements are "connected", "engaged", "coupled", "adjacent", "next to", " It is described using various terms including "on top of", "above", "below", and "disposed". In the present disclosure, when describing a relationship between a first element and a second element, unless explicitly stated as "directly", such relationship is such that there is no other intervening element between the first element and the second element. It may be a direct relationship that does not exist, or it may be an indirect relationship in which one or more intervening 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 interpreted to mean logical (A OR B OR C) using a non-exclusive logical OR, "at least one of A, B at least one of, 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 (23)

A heater system comprising:
A heater bundle comprising:
at least one heater assembly comprising a plurality of heater units, wherein at least one of the plurality of heater units defines at least one independently controlled heating zone of heater assembly; and
a plurality of power conductors electrically connected to the heater units; comprising,
heater bundle; and
a power supply including a controller configured to modulate power supplied to the at least one independently controlled heating zone via the power conductors;
The controller is configured to calculate a temperature in the at least one heater unit based on a predefined model and at least one input, and wherein the controller is further configured to calculate, based on the calculated temperature, the at least one heater unit. to regulate the power supplied to
heater system. The heater system of claim 1 , wherein the at least one heater unit is an end heater unit. The heater system of claim 1 , wherein the at least one input includes a temperature at another location within the heater bundle. The heater system of claim 1 , wherein the at least one input comprises at least one temperature of at least one heater unit of the plurality of heater units. The heater system of claim 1 , wherein the at least one input comprises a power consumption of the heater bundle. The heater system of claim 1 , wherein the at least one input comprises an average power consumption of the heater bundle over a predetermined period of time. The heater system of claim 1 , wherein the at least one input comprises a voltage of the heater bundle and/or a voltage of at least one of the heater units. The heater system of claim 1 , wherein the at least one input comprises a current of the heater bundle and/or a current of at least one of the heater units. The heater system of claim 1 , wherein the at least one input comprises an amount of current leakage of the heater bundle. The heater system of claim 1 , wherein the at least one input comprises an insulation resistance of the heater bundle. The heater system of claim 1 , wherein the at least one input comprises at least one of a fluid temperature, a fluid velocity, a fluid velocity, and a fluid mass flow rate. The method of claim 1 , wherein the controller comprises: supplying a known current to the plurality of heater units; measuring a voltage in the at least one independently controlled heating zone; and and comparing a voltage to a nominal voltage associated with the known current to ascertain voltage deviations and/or corresponding resistance deviations. The method of claim 1 , wherein the controller comprises: supplying a known voltage to the plurality of heater units; measuring a current in the at least one independently controlled heating zone; and converting the measured current to the known voltage. and ascertaining a current deviation and/or a corresponding resistance deviation compared to a nominal current associated with a voltage of the heater system. A fluid heating device comprising:
a sealed housing defining an inner chamber and having a fluid inlet and a fluid outlet; and
The heater system of claim 1 , wherein the at least one heater assembly is disposed within the inner chamber of the housing;
wherein the at least one heater assembly is adapted to provide a responsive heat distribution to the fluid within the housing;
fluid heating device. A heater system, the heater system comprising:
a heater assembly comprising a plurality of heater units, at least one of the heater units defining at least one independently controlled heating zone;
a plurality of power conductors electrically connected to the heater units; and
a power supply including a controller configured to regulate power supplied to the at least one independently controlled heating zone via the power conductors;
The controller is configured to calculate a temperature in the at least one heater unit based on a predefined model and at least one input, and wherein the controller is further configured to calculate, based on the calculated temperature, the at least one heater unit. to regulate the power supplied to
heater system. 16. The heater system of claim 15, wherein the at least one heater unit is an end heater unit. A fluid heating device comprising:
a sealed housing defining an inner chamber and having a fluid inlet and a fluid outlet; and
16. The heater system of claim 15, wherein the heater assembly comprises: a heater system disposed within the inner chamber of the housing;
wherein the heater assembly is adapted to provide a responsive heat distribution to the fluid within the housing;
fluid heating device. 16. The method of claim 15, wherein the controller comprises: supplying a known current to the plurality of heater units; measuring a voltage in the at least one independently controlled heating zone; and converting the measured voltage to the known voltage. and ascertaining a voltage deviation and/or a corresponding resistance deviation compared to a nominal voltage associated with a current in the heater system. 16. The method of claim 15, wherein the controller comprises: supplying a known voltage to the plurality of heater units; measuring a current in the at least one independently controlled heating zone; and ascertaining a current deviation and/or a corresponding resistance deviation compared to a nominal current associated with a voltage of the heater system. A heater system, the heater system comprising:
a heater assembly comprising a plurality of heater units, wherein more than one of the plurality of heater units defines at least one independently controlled heating zone;
a plurality of power conductors electrically connected to the heater units; and
a power supply including a controller configured to regulate power supplied to the independently controlled heating zones via the power conductors;
The controller is configured to calculate a temperature in the one or more heater units based on a predefined model and at least one input, and wherein the controller is further configured to calculate a temperature in the one or more heater units based on the calculated temperature. regulating the power supplied to the units,
heater system. 21. The heater system of claim 20, wherein the at least one heater unit is an end heater unit. 21. The method of claim 20, wherein the controller comprises: supplying a known current to the plurality of heater units; measuring a voltage in the at least one independently controlled heating zone; and converting the measured voltage to the known voltage. and ascertaining a voltage deviation and/or a corresponding resistance deviation compared to a nominal voltage associated with a current in the heater system. 21. The method of claim 20, wherein the controller comprises: supplying a known voltage to the plurality of heater units; measuring a current in the at least one independently controlled heating zone; and converting the measured current to the known voltage. and identifying a current deviation and/or a corresponding resistance deviation compared to a nominal current associated with a voltage of the heater system.

Images