Heating Control Method, Apparatus and System for Maintaining Temperature of Target Fluids in Tanks and Fluid Transfer Lines

Abstract

The present invention relates to a heating control system for maintaining the temperature of a plurality of temperature-maintaining fluids, wherein each of the plurality of temperature-maintaining fluids corresponds to either a tank or a fluid transfer line, and a heater channel corresponding to each of the plurality of temperature-maintaining fluids is set, and a temperature input unit receives a temperature input value corresponding to the temperature at the time of temperature detection of the temperature-maintaining fluid corresponding to each of the plurality of heater channels; a setting value storage unit storing, for each of the plurality of heater channels, a set temperature value corresponding to the target maintenance temperature of the corresponding temperature-maintaining fluid, a lower error range based on the set temperature value, an upper error range based on the set temperature value, a temperature rise reference value for determining channel matching error, and a channel matching error alarm delay time; a plurality of heater units for heating the temperature-maintaining fluids corresponding to each of the plurality of heater channels; and a plurality of SSR driving units corresponding to each of the plurality of heater units and controlling the power supply to the corresponding heater units. A heating control system is provided, comprising: a touch panel unit that, for each of the plurality of heater channels, displays a temperature input value corresponding to the temperature at the time of temperature detection, a set temperature value corresponding to the target maintenance temperature, an SSR control output status, a heater on command status, and an alarm status, and receives a heater on command or a heater off command for each of the plurality of heater channels; and a control unit that generates a control signal for each of the plurality of SSR driving units and alarm information displayed on the touch panel unit using a temperature input value input through the temperature input unit, a set temperature value stored in the set value storage unit, a lower error range, an upper error range, a temperature rise reference value for determining channel matching error, and a channel matching error alarm delay time.

Description

Technology Field

[0001] The present invention relates to heating control technology for industrial automation equipment, and more specifically, to a heating control system for maintaining the temperature of a fluid subject to temperature maintenance, such as a chemical liquid, process liquid, or liquid, which is contained in a tank or transported through a fluid transfer line, within a certain range in semiconductor process equipment, chemical supply equipment, chemical liquid transfer equipment, or liquid transfer equipment. Background Technology

[0003] In industrial automation equipment such as semiconductor process facilities, chemical supply facilities, chemical transfer facilities, and liquid transfer facilities, equipment is used to supply chemicals, process fluids, or liquids stored in tanks to process devices or to transfer them to specific locations via fluid transfer lines. In such facilities, since the temperature of the fluid can affect process quality, fluid viscosity, transfer stability, and equipment operational stability, heating control technology may be utilized to maintain the fluid temperature within a certain range by installing heaters in tanks or fluid transfer lines and controlling the operation of the heaters.

[0004] Generally, a heating control system receives a temperature value from a temperature sensor installed in a tank or fluid transfer line, controls the supply of power to a heater when the input temperature value is lower than a set temperature, and operates by cutting off or regulating the power supply to the heater when the input temperature value reaches a target temperature range. Such heating control can be implemented using a control device, a temperature input unit, a power control unit, a heater, and a display input device, and in one embodiment, it can be implemented using a PLC, an SSR, an HMI, or a touch panel.

[0005] However, in industrial automation facilities, a single heating control system often manages multiple tanks or fluid transfer lines. In such cases, since multiple temperature sensors, heaters, power control units, and control channels are installed corresponding to each tank or fluid transfer line, there is a possibility of mismatching between heater channels during on-site wiring, construction, maintenance, or channel setup. For example, even if a specific heater channel is activated to raise the temperature of a particular tank, the heater in a different tank or fluid transfer line may actually be activated, or the temperature value displayed on a specific heater channel may be the temperature of a different location rather than the temperature of the fluid intended for temperature maintenance.

[0006] When such channel matching errors occur, users may perceive a specific heater channel as operating normally on the display input device; however, in the actual field, unintended tanks or fluid transfer lines may be heated, or the fluid requiring temperature maintenance may not be heated sufficiently. Particularly for fluids such as chemicals, process fluids, or liquids that may increase in viscosity or solidify with a drop in temperature, failure to properly maintain the temperature can lead to fluid transfer failures, line blockages, process delays, or equipment malfunctions.

[0007] Furthermore, conventional heating control methods often remain limited to controlling the heater's on / off state by comparing the input temperature value with the set temperature. In this case, it is difficult to distinguish between situations where the temperature does not rise despite the heater operating, where the temperature rises partially and then stagnates, or where the temperature rises abnormally rapidly. Consequently, there is a problem in that the user must personally inspect the site for causes such as failure of the power control unit, heater disconnection, circuit breaker off, power supply abnormalities, insufficient heater capacity, increased fluid volume, increased flow rate, errors in the temperature sensor installation location, miswiring of the temperature input system, or the heater's air heating state.

[0008] Furthermore, the heating control system may experience power outages, momentary power outages, or power re-application during the operation of process equipment. In such cases, if all heaters are kept in a stopped state without considering the heater operating state prior to the power cutoff, the temperature of the fluid to be maintained may drop; conversely, if all heaters are automatically restarted, safety issues may arise due to sensor errors, circuit breaker malfunctions, overload relay operation, or the heaters operating again in a high-temperature state.

[0009] Therefore, in a heating control system that manages heater channels corresponding to multiple tanks or multiple fluid transfer lines, there is a need for technology that goes beyond simple temperature comparison control to detect matching errors between heater channels, distinguish and display abnormal temperature responses due to heater operation, and reliably manage heating delays, power re-application, or instantaneous power outage recovery situations. Prior art literature

[0011] Korean Registered Patent Publication No. 10-1646438 (Method for controlling temperature of a urea tank and the control device thereof) The problem to be solved

[0012] The present invention aims to provide a heating control system capable of stably maintaining the temperature of a temperature-maintaining fluid contained in a tank or conveyed through a fluid transfer line in an industrial automation facility.

[0013] The present invention aims to provide a heating control system capable of verifying whether heating control for a specific heater channel normally corresponds to a fluid intended for temperature maintenance during the process of managing multiple heater channels corresponding to multiple tanks or multiple fluid transfer lines, and detecting channel matching errors caused by miswiring, incorrect installation, or mismatch in channel settings between heater channels.

[0014] The present invention aims to provide a heating control system capable of reducing discrepancies between the operating state on the display input device and the actual power supply state of the heater unit by managing the heater on command state, the actual power control state, and the temperature input value separately, even when a user sets a specific heater channel as the operating target.

[0015] The present invention aims to provide a heating control system capable of distinguishing between a state where the temperature does not rise, a state where the temperature rises partially and then stagnates, or a state where the temperature rises abnormally rapidly, by utilizing a change pattern of the temperature input value while heating control is performed on a heater unit, and displaying candidate causes of abnormality corresponding to each state.

[0016] The present invention aims to provide a heating control system capable of determining a heating delay state or a heating delay candidate state by utilizing the temperature rise rate and the estimated time to reach the lower limit control temperature, rather than merely making a determination based on the current temperature value when the time it takes for a temperature-maintaining fluid to reach a target maintenance temperature range is delayed.

[0017] The present invention aims to provide a heating control system capable of reducing both the temperature drop of a fluid subject to temperature maintenance and the risk of unnecessary reheating by determining whether to automatically restore a heater channel by considering the heater operating state prior to power cutoff and recovery judgment information together in the context of a power outage, momentary power outage, or power re-application.

[0018] The problems to be solved by the present invention are not limited to those mentioned above, and may include other problems within the scope that can be understood from the technical concept of the present invention. means of solving the problem

[0020] A heating control system for maintaining a tank temperature according to an embodiment of the present invention comprises: a heating control system for maintaining the temperature of a plurality of temperature-maintaining fluids, wherein each of the plurality of temperature-maintaining fluids corresponds to either a tank or a fluid transfer line, and a heater channel corresponding to each of the plurality of temperature-maintaining fluids is set, and a temperature input unit receives a temperature input value corresponding to the temperature at the time of temperature detection of the temperature-maintaining fluid corresponding to each of the plurality of heater channels; a setting value storage unit storing, for each of the plurality of heater channels, a setting temperature value corresponding to the target maintenance temperature of the corresponding temperature-maintaining fluid, a lower error range based on the setting temperature value, an upper error range based on the setting temperature value, a temperature rise reference value for determining a channel matching error, and a channel matching error alarm delay time; a plurality of heater units corresponding to each of the plurality of heater channels and heating the temperature-maintaining fluid contained in the corresponding tank or the temperature-maintaining fluid transferred through the corresponding fluid transfer line; and a plurality of SSR driving units corresponding to each of the plurality of heater units and controlling the power supply to the corresponding heater unit. For each of the plurality of heater channels, a touch panel unit that displays a temperature input value corresponding to the temperature at the time of temperature detection, a set temperature value corresponding to the target maintenance temperature, an SSR control output status, a heater on command status, and an alarm status, and receives a heater on command or a heater off command for each of the plurality of heater channels; and a control unit that generates a control signal for each of the plurality of SSR driving units and alarm information displayed on the touch panel unit using the temperature input value input through the temperature input unit, the set temperature value stored in the set value storage unit, a lower error range, an upper error range, a temperature rise reference value for determining channel matching error, and a channel matching error alarm delay time.

[0021] The control unit sets a heater channel among the plurality of heater channels in which the heater on command state is on as a selected heater channel, and when an on control signal is output to an SSR driver corresponding to the selected heater channel, sets one or more heater channels among the remaining heater channels excluding the selected heater channel in which the heater on command state is off and an off control signal is output to a corresponding SSR driver as monitored heater channels, and when it is determined that the temperature input value of the monitored heater channel has increased in response to the output of the on control signal for the selected heater channel, generates a channel matching error alarm between the selected heater channel and the monitored heater channel.

[0022] The control unit may set the heater on command state of any one heater channel among the plurality of heater channels to an ON state when a heater on command for any one heater channel is input through the touch panel unit, and may set the heater on command state of any one heater channel among the plurality of heater channels to an OFF state when a heater off command is input through the touch panel unit, and may output an OFF control signal to an SSR driver corresponding to any one heater channel, and may set the heater channel among the plurality of heater channels whose heater on command state is ON as a temperature control target heater channel, and may perform temperature control processing for each of the temperature control target heater channels, and may set the heater channel on which the temperature control processing is performed as a selected heater channel, and may output an ON control signal to an SSR driver corresponding to the selected heater channel if the temperature input value of the selected heater channel is less than or equal to the lower limit control temperature value obtained by subtracting the lower limit error range of the selected heater channel from the set temperature value of the selected heater channel, and the upper limit of the selected heater channel If the upper limit control temperature value, including the error range, is greater than or equal to the value, an off control signal can be output to the SSR driver corresponding to the selected heater channel, and if the temperature input value of the selected heater channel exceeds the lower limit control temperature value and is less than the upper limit control temperature value, the previous control signal for the SSR driver corresponding to the selected heater channel can be maintained.

[0023] The control unit may set the time at which an ON control signal is output to an SSR driver corresponding to the selected heater channel as the monitoring start time, and at the monitoring start time, among the plurality of heater channels excluding the selected heater channel, one or more heater channels in which the heater ON command state is OFF and an OFF control signal is output to the corresponding SSR driver may be set as the monitoring target heater channels, and for each of the monitoring target heater channels, the temperature input value at the monitoring start time may be stored as a comparison reference temperature value, and while an ON control signal is output to the SSR driver corresponding to the selected heater channel, the heater ON command state of the monitoring target heater channel is maintained in an OFF state, and an OFF control signal is output to the SSR driver corresponding to the monitoring target heater channel, the temperature rise amount may be calculated by subtracting the comparison reference temperature value of the corresponding monitoring target heater channel from the temperature input value of each of the monitoring target heater channels, and when the ON control signal output to the SSR driver corresponding to the selected heater channel ends, the calculation of the temperature rise amount for the monitoring target heater channel may end, and when the ON control signal is again output to the SSR driver corresponding to the selected heater channel When outputting, a new monitoring start time is set, and at the new monitoring start time, one or more monitoring target heater channels are newly set, and the temperature input value of each newly set monitoring target heater channel can be stored as a new comparison reference temperature value, and in order to determine whether there is a channel matching error according to the ON control signal output of the selected heater channel, if the temperature rise amount of any one of the monitoring target heater channels is greater than or equal to the channel matching error judgment temperature rise reference value stored corresponding to the selected heater channel and is maintained for longer than the channel matching error alarm delay time stored corresponding to the selected heater channel,In response to the ON control signal output for the selected heater channel, it is determined that the temperature input value of any one of the monitored heater channels has increased, and a channel matching error alarm can be generated between the selected heater channel and any one of the monitored heater channels. When the channel matching error alarm is generated, the heater ON command status of the selected heater channel and any one of the monitored heater channels can be switched to an OFF state. Furthermore, until an administrator confirmation input and an alarm release input regarding the channel matching error alarm are input through the touch panel, even if a heater ON command for the selected heater channel or any one of the monitored heater channels corresponding to the channel matching error alarm is input through the touch panel, the heater ON command status of the corresponding heater channel can be controlled so as not to be changed to an ON state.

[0024] The above setting value storage unit further stores, for each of the plurality of heater channels, an SSR inspection delay time, a first reference change amount, a second reference change amount, a temperature stagnation reference value, and a number of consecutive stagnation judgments, wherein the first reference change amount and the second reference change amount are temperature change amount judgment values ​​based on the temperature input value at the time of diagnosis start, and the second reference change amount may be a value greater than the first reference change amount.

[0025] The control unit above may set a heater channel among the plurality of heater channels to which an ON control signal is output to a corresponding SSR driver as a heater channel to be diagnosed in order to diagnose the heating response for each of the plurality of heater channels, and may set the time at which an ON control signal is output to the SSR driver corresponding to the heater channel to be diagnosed as the diagnosis start time; may store the temperature input value of the heater channel to be diagnosed at the diagnosis start time as a diagnosis reference temperature value; may store the temperature input values ​​input for each temperature detection time point during the SSR inspection delay time of the heater channel to be diagnosed as a plurality of diagnosis temperature values ​​in chronological order; may determine a non-rising pattern if the amount of temperature change obtained by subtracting the diagnosis reference temperature value from the diagnosis temperature value at the time when the SSR inspection delay time has elapsed is less than the first reference change amount of the heater channel to be diagnosed, and after the amount of temperature change obtained by subtracting the diagnosis reference temperature value from any one of the plurality of diagnosis temperature values ​​stored during the SSR inspection delay time becomes greater than or equal to the first reference change amount of the heater channel to be diagnosed, and the number of consecutive diagnosis times is greater than or equal to the number of consecutive times for determining stagnation of the heater channel to be diagnosed, and each At the time of diagnosis, if the amount of change compared to the previous diagnosis temperature value is within the temperature stagnation threshold value of the heater channel to be diagnosed, it can be determined as a stagnation pattern; and if the amount of temperature change, calculated by subtracting the diagnosis threshold temperature value from the maximum diagnosis temperature value among the plurality of diagnosis temperature values ​​stored during the SSR inspection delay time, exceeds the second threshold change amount of the heater channel to be diagnosed, it can be determined as a rapid rise pattern; and if the above rise pattern is determined, first abnormal cause candidate information corresponding to at least one of SSR non-operation, heater open circuit, possibility of circuit breaker off, or possibility of power supply abnormality for the heater channel to be diagnosed can be generated, and if the above stagnation pattern is determined, insufficient heater capacity for the heater channel to be diagnosed,Can generate second abnormal cause candidate information corresponding to at least one of an increase in the amount of fluid in the tank corresponding to the heater channel to be diagnosed, an increase in the flow rate of the fluid transfer line corresponding to the heater channel to be diagnosed, or an increase in the heat load; if the above-mentioned rapid rise pattern is determined, can generate third abnormal cause candidate information corresponding to at least one of a miswiring or misinstallation of the temperature input system for the heater channel to be diagnosed, a shortage of the fluid to be maintained in the tank corresponding to the heater channel to be diagnosed, a shortage of the fluid to be maintained transferred through the fluid transfer line corresponding to the heater channel to be diagnosed, or an air-heating state of the heater part corresponding to the heater channel to be diagnosed; can switch the heater on command state of the heater channel to be diagnosed, where the first abnormal cause candidate information, the second abnormal cause candidate information, or the third abnormal cause candidate information is generated, to an off state; and can control the touch panel unit to display the heater channel to be diagnosed, the temperature input value of the heater channel to be diagnosed, the SSR control output state of the heater channel to be diagnosed, and the first abnormal cause candidate information, the second abnormal cause candidate information, or the third abnormal cause candidate information.

[0026] The heating control system may further include: a power state input unit that receives a circuit breaker state and an overload relay state corresponding to each of the plurality of heater channels; a sensor state input unit that receives a sensor error state of a temperature input system corresponding to each of the plurality of heater channels; and a state storage unit that includes a non-volatile memory for storing a heater-on command state for each of the plurality of heater channels.

[0027] The above setting value storage unit further stores, for each of the plurality of heater channels, a reference rise rate used as a heating delay judgment criterion, a reference time for calculating the rise rate, an automatic recovery setting value indicating whether to restore the heater-on command state upon power re-application or recovery from a momentary power outage, an automatic recovery delay time, and a high temperature alarm reference value, wherein the reference rise rate may be a reference value for determining the degree of temperature rise during the reference time for calculating the rise rate.

[0028] The control unit may set a heater channel among the plurality of heater channels in which the heater-on command state is set to ON as the heater channel subject to delay determination, and may set the time when the heater-on command state of the heater channel subject to delay determination is set to ON as the heating start time; may store the temperature input value of the heater channel subject to delay determination at the heating start time as the heating start temperature value; if the heating start temperature value is less than the lower limit control temperature value obtained by subtracting the lower limit error range of the heater channel subject to delay determination from the set temperature value corresponding to the target maintenance temperature of the heater channel subject to delay determination, the difference in lower limit reached temperature may be calculated by subtracting the heating start temperature value from the lower limit control temperature value; the temperature rise rate of the heater channel subject to delay determination may be calculated using the temperature input value input at each temperature detection time during the rise rate calculation reference time of the heater channel subject to delay determination after the heating start time; if the temperature rise rate is greater than or equal to the reference rise rate of the heater channel subject to delay determination, the estimated time to reach the lower limit control temperature may be calculated by dividing the difference in lower limit reached temperature by the temperature rise rate, and the heater subject to delay determination If the temperature input value of the channel fails to rise above the lower limit control temperature value from the heating start time until the estimated time to reach the lower limit control temperature has elapsed, a heating delay alarm may be generated; if the temperature rise rate is less than the reference rise rate of the heater channel subject to delay determination, a heating delay candidate alarm may be generated; and if the heating delay alarm is generated, the touch panel unit may be controlled to display heating delay information including the estimated time to reach the lower limit control temperature, the actual elapsed time, and the temperature input value of the heater channel subject to delay determination; and if the heating delay candidate alarm is generated,The touch panel unit can be controlled to display heating delay candidate information including the actual elapsed time and the temperature input value of the heater channel subject to delay determination, and the heater ON command status of each of the plurality of heater channels can be periodically stored in the state storage unit, and when power re-application or momentary power outage recovery of the heating control system is detected, the heater ON command status of each of the plurality of heater channels stored in the state storage unit before power cut-off can be verified as the heater operating state prior to the power outage, and recovery determination information including the temperature input value, sensor error status, circuit breaker status, and overload relay status can be verified for each of the plurality of heater channels after power re-application or momentary power outage recovery, and if the automatic recovery setting value of the heater channel subject to recovery, whose heater operating state prior to the power outage was ON among the plurality of heater channels, is in the used state, when the automatic recovery delay time of the heater channel subject to recovery has elapsed, if the recovery determination information of the heater channel subject to recovery satisfies the recovery acceptance condition, the heater ON command status of the heater channel subject to recovery can be restored to the ON state, and the recovery acceptance condition is the temperature input value of the heater channel subject to recovery entered at the time when the automatic recovery delay time has elapsed, which is the high temperature alarm reference value of the heater channel subject to recovery. It may include conditions where the sensor error state of the heater channel to be recovered is released, and the circuit breaker state and overload relay state of the heater channel to be recovered are in a normal state, and when the automatic recovery setting value of the heater channel to be recovered is in an unused state, momentary power outage alarm information may be generated and the heater on command state of the heater channel to be recovered may be maintained in an off state. Effects of the invention

[0030] According to the present invention, the temperature of a temperature-maintaining fluid, which is contained in a tank or transported through a fluid transfer line in an industrial automation facility, can be stably maintained.

[0031] Furthermore, according to the present invention, in the process of managing a plurality of heater channels corresponding to a plurality of tanks or a plurality of fluid transfer lines, it is possible to verify whether the heating control for a specific heater channel corresponds normally to the fluid intended for temperature maintenance. Accordingly, channel matching errors caused by miswiring, incorrect installation, or inconsistencies in channel settings between heater channels can be detected early, and problems such as unintended tanks or fluid transfer lines being heated, or the fluid intended for temperature maintenance not being heated, can be reduced.

[0032] In addition, according to the present invention, the heater-on command status, the actual power control status, and the temperature input value can be managed separately from each other. Accordingly, the discrepancy between the operating status of the heater channel checked by the user and the actual power supply status of the heater unit can be reduced, and multiple heater channels can be managed more clearly.

[0033] In addition, according to the present invention, by checking the pattern of change in the temperature input value while heating control is performed on the heater unit, it is possible to distinguish between a state where the temperature does not rise despite the heater operating, a state where the temperature rises partially and then stagnates, or a state where the temperature rises abnormally rapidly. Accordingly, candidate causes of abnormalities such as non-operation of the power control unit, heater disconnection, circuit breaker off, power supply abnormality, insufficient heater capacity, increase in fluid volume, increase in flow rate, miswiring or misinstallation of the temperature input system, insufficient fluid for temperature maintenance, or an air-heating state of the heater unit can be provided to the user.

[0034] In addition, according to the present invention, the temperature rise rate and the estimated time to reach the lower limit control temperature can be utilized during the process in which a temperature-maintaining fluid reaches the target maintenance temperature range. Accordingly, rather than simply checking a state where the current temperature value is low, it is possible to distinguish and determine a heating delay state or a heating delay candidate state, and to identify in advance situations that may lead to fluid transfer failure, line blockage, or process delay.

[0035] In addition, according to the present invention, the heater operating state prior to power cutoff and recovery judgment information can be checked together in the event of a power outage, momentary power outage, or power re-application. Accordingly, while reducing the temperature drop of the fluid to be maintained, the risk of the heater unit being unnecessarily restarted due to sensor errors, circuit breaker malfunctions, overload relay operation, or high temperature conditions can be reduced.

[0036] In addition, according to the present invention, temperature control for a plurality of heater channels, detection of channel matching errors, diagnosis of heating response, determination of heating delay, and processing of power re-application or instantaneous power outage recovery can be verified through a display input device. Accordingly, field workers or managers can more easily identify the operating status and abnormal conditions of the heating control system, and reduce maintenance and inspection time.

[0037] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by a person skilled in the art from the description below. Brief explanation of the drawing

[0039] FIG. 1 is a block diagram schematically showing the overall configuration of a heating control system according to one embodiment of the present invention. FIG. 2 is a block diagram showing the corresponding relationships of a plurality of tanks, a plurality of fluid transfer lines, and a plurality of heater channels of a heating control system according to one embodiment of the present invention. Specific details for implementing the invention

[0040] Hereinafter, embodiments are described in detail with reference to the attached drawings. However, various modifications may be made to the embodiments, and thus the scope of the patent application is not limited or restricted by these embodiments. It should be understood that all modifications, equivalents, and substitutions to the embodiments are included within the scope of the rights.

[0041] Specific structural or functional descriptions of the embodiments are disclosed for illustrative purposes only and may be modified and implemented in various forms. Accordingly, the embodiments are not limited to the specific disclosed forms, and the scope of this specification includes modifications, equivalents, or substitutions that fall within the technical concept.

[0042] Terms such as "first" or "second" may be used to describe various components, but these terms should be interpreted solely for the purpose of distinguishing one component from another.

[0043] For example, the first component may be named the second component, and similarly, the second component may also be named the first component.

[0044] When it is stated that a component is "connected" to another component, it should be understood that it may be directly connected to or coupled with that other component, or that there may be other components in between.

[0045] The terms used in the embodiments are for illustrative purposes only and should not be interpreted as intended to be limiting. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0046] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the embodiments pertain. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0047] In addition, when describing with reference to the attached drawings, identical components are assigned the same reference numeral regardless of drawing symbols, and redundant descriptions thereof are omitted. In describing the embodiments, if it is determined that a detailed description of related prior art could unnecessarily obscure the essence of the embodiments, such detailed description is omitted.

[0048] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0049] In the embodiments of the present invention, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in the embodiments of the present invention.

[0050] The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are exemplary, and therefore the present invention is not limited to the depicted details. Furthermore, in describing the present invention, if it is determined that a detailed description of related known technology may unnecessarily obscure the essence of the present invention, such detailed description is omitted. Where terms such as "includes," "has," or "is made up" are used in this specification, other parts may be added unless "only" is used. Where a component is expressed in the singular, it includes cases where it includes the plural unless specifically stated otherwise.

[0051] In interpreting the components, they are interpreted to include a margin of error even in the absence of a separate explicit statement.

[0052] In the case of describing positional relationships, for example, when the positional relationship between two parts is described using expressions such as 'on,' 'upper,' 'lower,' or 'next to,' one or more other parts may be located between the two parts unless 'immediately' or 'directly' is used.

[0053] When elements or layers are referred to as "on" another element or layer, this includes cases where another layer or element is placed directly on top of or in between. Throughout the specification, the same reference numerals refer to the same components.

[0054] The size and thickness of each component shown in the drawings are illustrated for convenience of explanation, and the present invention is not necessarily limited to the size and thickness of the illustrated components.

[0055] The features of each of the various embodiments of the present invention may be combined or combined with one another, either partially or wholly, and as will be fully understood by those skilled in the art, various technical interlocking and operation are possible, and each embodiment may be implemented independently of one another or together in an interlocking relationship.

[0057] Hereinafter, a heating control system according to one embodiment of the present invention will be described with reference to FIGS. 1 and FIGS. 2.

[0059] FIG. 1 is a block diagram schematically showing the overall configuration of a heating control system according to one embodiment of the present invention, and FIG. 2 is a block diagram showing the corresponding relationship between a plurality of tanks, a plurality of fluid transfer lines, and a plurality of heater channels according to one embodiment of the present invention.

[0061] FIGS. 1 and 2 schematically illustrate the connection and correspondence relationships of the main components to aid in understanding the present invention. Accordingly, the actual placement location of each component, wiring type, number of signal lines, number of fluid transfer lines, number of tanks, number of heater channels, number of SSR drive units, and number of heater units are not limited to the examples shown in the drawings.

[0062] In addition, the temperature control processing, channel matching error determination processing, heating response diagnosis processing, heating delay determination processing, and power re-application or momentary power outage recovery processing described in this specification may not be illustrated in a separate flowchart for convenience of explanation. However, these processing may be performed by the operation of the temperature input unit, setting value storage unit, multiple SSR driving units, multiple heater units, touch panel unit, and control unit illustrated in FIGS. 1 and 2, and the specific processing order may be implemented according to the contents described in each embodiment of this specification.

[0063] The arrows shown in the drawing are intended to schematically represent the transmission flow of temperature input values, set values, control signals, heater on commands, heater off commands, alarm information, or status information. Therefore, the arrows shown in the drawing do not limit all actual wiring or signal transmission paths, and the control unit can manage the heater on command status, SSR control output status, temperature input value, and alarm status of each of the multiple heater channels in addition to the arrows shown in the drawing.

[0064] In addition, even if some detailed configurations or processing steps are omitted in the drawings, this is for the purpose of simplifying the drawings. Operations related to the input of temperature input values, storage of set values, output of control signals to the SSR driving unit, control of power supply to the heater unit, display and input through the touch panel unit, generation of alarm information, determination of channel matching errors, diagnosis of heating response, determination of heating delay, and power re-application or recovery from momentary power outage described in this specification may be performed under the control of the control unit.

[0066] Referring to FIG. 1, a heating control system according to one embodiment of the present invention may include a temperature input unit (100), a set value storage unit (200), a plurality of heater units (300), a plurality of SSR driving units (400), a touch panel unit (500), and a control unit (600).

[0067] The temperature input unit (100) can receive a temperature input value corresponding to the temperature at the time of temperature detection for each of the plurality of temperature-maintaining fluids and transmit it to the control unit (600). The setting value storage unit (200) can store a setting temperature value, a lower error range, an upper error range, a temperature rise reference value for determining channel matching errors, and a channel matching error alarm delay time corresponding to each of the plurality of heater channels.

[0068] The control unit (600) can generate control signals for each of the plurality of SSR driving units (400) and alarm information displayed on the touch panel unit (500) using the temperature input value input through the temperature input unit (100) and the setting value stored in the setting value storage unit (200). The plurality of SSR driving units (400) can control the power supply to each of the plurality of heater units (300) according to the control signal input from the control unit (600). The plurality of heater units (300) can directly or indirectly heat the temperature-maintaining fluid contained in the corresponding tank or the temperature-maintaining fluid being transported through the corresponding fluid transfer line.

[0069] Referring to FIG. 2, a plurality of tanks (700) may contain a fluid to be maintained at a temperature, and a plurality of fluid transfer lines (800) may transfer a fluid to be maintained at a temperature. Each of the plurality of heater channels (900) may be configured to correspond to either the plurality of tanks (700) or the plurality of fluid transfer lines (800).

[0070] In FIG. 2, the dotted box may schematically represent the corresponding relationship between the SSR drive unit and the heater unit for each heater channel. Each row inside the dotted box may represent the connection relationship between one heater channel, the SSR drive unit corresponding to the heater channel, and the heater unit corresponding to the heater channel. For example, the first heater channel may correspond to a temperature-maintaining fluid contained in the first tank, the second heater channel may correspond to a temperature-maintaining fluid contained in the second tank, and the third heater channel and the fourth heater channel may correspond to temperature-maintaining fluids conveyed through the first fluid transfer line and the second fluid transfer line, respectively.

[0071] Each heater channel may be a control unit for managing the temperature input value, set temperature value, heater unit, SSR driving unit, heater ON command status, SSR control output status, and alarm status of the corresponding temperature-maintaining fluid. Accordingly, the control unit (600) can distinguish each of the plurality of heater channels (900) to perform temperature control, determine channel matching errors, diagnose heating response, determine heating delay, and perform power re-application or instantaneous power outage recovery processing.

[0073] Meanwhile, for convenience of explanation in this specification, even if the heater unit (300), SSR drive unit (400), tank (700), fluid transfer line (800), heater channel (900), temperature input system, or temperature maintenance target fluid are described in a single number, this is not intended to limit the configuration to a single unit, and unless otherwise interpreted in the context, it may be applied to each of the plurality of heater units (300), plurality of SSR drive units (400), plurality of tanks (700), plurality of fluid transfer lines (800), plurality of heater channels (900), plurality of temperature input systems, or plurality of temperature maintenance target fluids.

[0075] Specifically, the heating control system according to the present invention is a system for maintaining the temperature of a plurality of temperature-maintaining fluids that are contained in a tank (700) or transferred through a fluid transfer line (800). Here, the temperature-maintaining fluid may refer to a liquid substance that needs to maintain its temperature within a certain range. The temperature-maintaining fluid may include water, cleaning solution, chemical solution, process solution, raw material solution, liquid solution, adhesive, resin, oil, food raw material, viscous fluid, or other fluids requiring temperature maintenance. The temperature of the temperature-maintaining fluid may be maintained while stored in the tank, or it may be maintained during the process of being transferred through the fluid transfer line. For example, the temperature-maintaining fluid may be a fluid used in semiconductor process equipment, chemical supply equipment, chemical solution transfer equipment, or liquid solution transfer equipment, and may be a fluid whose viscosity may increase or whose fluidity may decrease as the temperature decreases.

[0076] A tank (700) refers to a container or facility for storing or temporarily containing a fluid to be maintained at a temperature. The tank may be a process tank, a storage tank, a mixing tank, a chemical tank, a cleaning tank, a raw material tank, a blending tank, a circulation tank, a buffer tank, or a similar fluid receiving facility. The tank may be used for storage purposes to keep the fluid to be maintained at a temperature for a long time, or for buffer purposes to temporarily collect the fluid to be maintained at a temperature during a process. The tank may be formed of a metal material, a synthetic resin material, a lined material, a chemical-resistant material, or a material with insulation attached.

[0077] A fluid transfer line (800) refers to a pipe, conduit, tube, hose, or line facility that transfers a fluid to be maintained at a specific temperature from one location to another. The fluid transfer line may be placed between a tank and a process device, between tanks and tanks, between process devices and process devices, between a storage facility and a discharge facility, or between a pump and a point of use. The fluid transfer line may be a pipe in which a metal pipe, a synthetic resin pipe, a flexible hose, a tube, a jacket pipe, an insulated pipe, or a heating cable is placed. Since heat loss may occur during the transfer of the fluid to be maintained at a specific temperature, the fluid transfer line may be heated to maintain the viscosity, prevent solidification, prevent crystallization, maintain fluidity, or maintain the process temperature of the fluid to be maintained at a specific temperature.

[0078] Therefore, in the present invention, the object of temperature control is not limited to the tank (700) itself or the fluid transfer line (800) itself. In the present invention, the object of temperature control includes the temperature-maintaining fluid contained in the tank or the temperature-maintaining fluid transferred through the fluid transfer line. However, the heater unit (300), the temperature input system, and the SSR drive unit (400) may be installed or configured to correspond to the tank (700) in which the temperature-maintaining fluid is contained or the fluid transfer line (800) in which the temperature-maintaining fluid is transferred.

[0079] Multiple temperature-maintaining fluids may all be fluids contained in a tank (700), all be fluids transferred through a fluid transfer line (800), or some may be contained in a tank and others transferred through a fluid transfer line. For example, the first temperature-maintaining fluid may be a raw material liquid contained in a raw material tank, the second temperature-maintaining fluid may be a process liquid contained in a process liquid tank, and the third temperature-maintaining fluid may be a raw material liquid transferred through a fluid transfer line connecting the raw material tank and the process device. As another example, the multiple temperature-maintaining fluids may be fluids such as liquids, chemical solutions, or cleaning solutions, which may increase viscosity, solidify, or affect process quality if their temperature is not maintained.

[0080] A heater channel (900) corresponds to each of the multiple temperature-maintaining fluids. A heater channel refers to a control unit for managing a temperature input value, set temperature value, lower limit error range, upper limit error range, heater unit, SSR driving unit, heater ON command status, SSR control output status, and alarm status for a single temperature-maintaining fluid. A heater channel does not simply refer to a physical wiring terminal, but may be a logical control unit for the control unit (600) to distinguish each temperature-maintaining fluid and perform temperature control, alarm judgment, and status display.

[0081] A single heater channel may correspond to a single fluid to be maintained at a specific temperature. A single heater channel may be connected to a temperature input system that detects the temperature of the fluid to be maintained at a specific temperature, a heater unit that heats a tank containing the fluid to be maintained at a specific temperature or a fluid transfer line through which the fluid to be maintained at a specific temperature is transferred, an SSR drive unit that controls the power supply to the heater unit, a set temperature value corresponding to the target maintenance temperature of the fluid to be maintained at a specific temperature, and operating status information of the heater channel.

[0082] For example, the first heater channel may correspond to a temperature input value of a first temperature-maintaining fluid contained in a first tank, a set temperature value of the first temperature-maintaining fluid, a heater unit for heating the first tank or the first temperature-maintaining fluid contained in the first tank, and an SSR drive unit for controlling the power of said heater unit. As another example, the second heater channel may correspond to a temperature input value of a second temperature-maintaining fluid transferred through a first fluid transfer line, a set temperature value of the second temperature-maintaining fluid, a first fluid transfer line or a heater unit for heating the second temperature-maintaining fluid transferred through the first fluid transfer line, and an SSR drive unit for controlling the power of said heater unit.

[0083] The correspondence of the heater channels may be stored in the control unit (600) or the setting value storage unit (200). The correspondence of the heater channels may include heater channel identification information, temperature maintenance target fluid identification information, tank identification information, fluid transfer line identification information, temperature input system identification information, heater unit identification information, SSR drive unit identification information, and display name information. The display name information may be displayed as raw material tank, cleaning liquid tank, chemical liquid supply line, full supply line, circulation line, etc., so that the user can distinguish them on the touch panel unit (500).

[0084] If the correspondence of the heater channels is incorrectly set or the field wiring is incorrectly connected, the temperature input value of a temperature-maintaining fluid other than the intended temperature-maintaining fluid may increase, even though the control unit (600) has output an ON control signal to a specific heater channel. For example, even though an ON control signal has been output to a heater channel intended to heat a liquid medicine contained in a specific tank, the temperature input value of the liquid medicine being transported through a different fluid transport line may increase. The present invention enables such a situation to be determined as a channel matching error.

[0085] The temperature input unit (100) receives a temperature input value corresponding to the temperature at the time of temperature detection of the fluid to be maintained, which corresponds to each of the plurality of heater channels (900). The temperature input value is a detected value transmitted to the control unit (600) through the temperature input unit (100) and is distinguished from the set temperature value stored in the set value storage unit (200). The temperature input value may be a value that directly represents the temperature detected by the temperature sensor, or a value obtained by converting the voltage signal, current signal, or resistance value of the temperature sensor. The temperature input value may be a Celsius temperature value, a Fahrenheit temperature value, a digital temperature value, a temperature conversion value, or a numeric value that can be processed within the control unit (600).

[0086] The temperature input system may include a temperature sensor for detecting the temperature of a fluid to be maintained, wiring connecting the temperature sensor and the temperature input unit (100), an input terminal of the temperature input unit (100), an input channel transmitted from the temperature input unit (100) to the control unit (600), and channel setting information for matching the input channel to a heater channel in the control unit (600). The temperature input system does not simply refer to a single temperature sensor, but includes a path for detection, wiring, input, conversion, and channel matching until the temperature detection value of the fluid to be maintained is recognized as the temperature input value of a specific heater channel in the control unit (600).

[0087] The temperature detection point may refer to the point in time when the temperature input unit (100) receives a signal corresponding to the temperature of the fluid to be maintained, or when the control unit (600) reads the temperature input value. The temperature input value may be input repeatedly, and the control unit (600) may read the temperature input value at regular intervals and use it for temperature control, determining channel matching errors, diagnosing SSR, determining heating delay, or determining automatic recovery. The temperature detection period may be, for example, hundreds of milliseconds, 1 second, 5 seconds, 10 seconds, or a time interval set by the user, but is not limited to a specific value.

[0088] The temperature input unit (100) may receive a temperature detection signal from a thermocouple, RTD sensor, thermistor, infrared temperature sensor, digital temperature sensor, or other temperature detection element. The temperature sensor may be installed inside the tank, on the outer surface of the tank, at the bottom of the tank, at the tank discharge section, inside the fluid transfer line, on the outer surface of the fluid transfer line, on the inlet side of the fluid transfer line, on the outlet side of the fluid transfer line, or at a location that can represent the temperature of the fluid to be maintained. The temperature input unit (100) may include a temperature sensor input module, an analog input module, a digital input module, a communication input module, a temperature conversion circuit, or an input circuit of an industrial controller. The temperature input unit (100) may filter, correct, scale, or unit convert the input temperature detection signal to provide it as a temperature input value. For example, the temperature input unit (100) may convert a 4 to 20 mA signal into a temperature value or convert the voltage value of the thermocouple into a temperature value.

[0089] Miswiring of the temperature input system may refer to a state in which the wiring of a temperature sensor that is supposed to correspond to a specific heater channel is connected to an input terminal of the temperature input unit (100) of a different heater channel, or the input terminals of the temperature input unit (100) are connected in a swapped manner, or the signal line of the temperature sensor is connected to an input channel recognized by the control unit (600) as the temperature input value of a different heater channel. Misinstallation of the temperature input system may refer to a state in which the temperature sensor is installed at a location other than the temperature detection location of the tank or fluid transfer line corresponding to the heater channel, such as a location excessively close to a different tank, a different fluid transfer line, a location excessively close to a heat source, or a location that detects a temperature significantly different from the representative temperature of the fluid to be maintained. Additionally, misinstallation of the temperature input system may include a state in which the temperature sensor fails to make sufficient contact with the fluid to be maintained inside the tank, fails to make sufficient thermal contact with the outer surface of the fluid transfer line, or detects a temperature different from the actual temperature of the fluid to be maintained due to insulation material or a fixing member.

[0090] A temperature input channel setting error may refer to a state in which a specific input channel of the temperature input unit (100) is set to correspond to a different heater channel in the control unit (600) or touch panel unit (500). For example, even though a temperature sensor detecting the temperature of the first tank is actually connected to the first input terminal of the temperature input unit (100), the first input terminal may be set as the temperature input value of the second heater channel in the channel setting information of the control unit (600). In this case, since the control unit (600) can read the temperature of the first tank as the temperature input value of the second heater channel, a discrepancy may occur between the temperature input value between the heater channels and the fluid to be maintained at an actual temperature.

[0091] The setting value storage unit (200) stores a setting temperature value, a lower error range, an upper error range, a temperature rise reference value for determining channel matching error, and a channel matching error alarm delay time for each of the plurality of heater channels (900). The setting value storage unit (200) may be a non-volatile memory, a volatile memory, a PLC memory, a data register of an industrial controller, an internal storage area of ​​a touch panel unit (500), an external storage device, or a storage area accessible via communication.

[0092] The set temperature value corresponds to the target maintenance temperature of the corresponding temperature-maintaining fluid. The set temperature value can be entered by the user through the touch panel unit (500), or set through an upper control unit, a process control server, a communication unit, or pre-stored recipe data. The set temperature value can be set differently for each heater channel. For a heater channel corresponding to a temperature-maintaining fluid contained in a tank, the set temperature value can be set based on the storage temperature or process temperature of the fluid in the tank, and for a heater channel corresponding to a temperature-maintaining fluid transferred through a fluid transfer line, the set temperature value can be set based on a temperature range where the fluid passing through the line does not solidify or increase in viscosity.

[0093] The lower error range refers to the allowable range on the lower side based on the set temperature value. The control unit (600) can calculate the lower control temperature value by subtracting the lower error range from the set temperature value. The upper error range refers to the allowable range on the higher side based on the set temperature value. The control unit (600) can calculate the upper control temperature value by adding the upper error range to the set temperature value. The lower error range and the upper error range may be the same value or different values. For example, if the set temperature value is 60℃, the lower error range is 2℃, and the upper error range is 3℃, the lower control temperature value may be 58℃ and the upper control temperature value may be 63℃.

[0094] The heater unit (300) directly or indirectly heats the temperature-maintaining fluid corresponding to each of the plurality of heater channels (900). The heater unit can convert electrical energy into thermal energy to supply heat to the temperature-maintaining fluid contained in the tank or to the temperature-maintaining fluid being transported through the fluid transfer line. The heater unit corresponding to the tank may be placed on the outer surface, bottom surface, side, internal jacket, circulation piping, or heat transfer member connected to the tank. The heater unit corresponding to the fluid transfer line may be wound along the outer surface of the fluid transfer line, attached along the length of the line, or placed together with a jacket or insulation material that wraps around the line. The heater unit may be a band heater, cartridge heater, plate heater, planar heater, heating wire heater, heating cable, jacket heater, silicone rubber heater, electric resistance heater, or other electric heater.

[0095] The statement that the heater unit (300) directly heats the fluid to be maintained in temperature may mean that the heater unit comes into direct contact with the fluid to be maintained in temperature or supplies heat to the internal space through which the fluid to be maintained in temperature flows. The statement that the heater unit indirectly heats the fluid to be maintained in temperature may mean that the heater unit heats the wall of the tank, the bottom of the tank, the outer surface of the fluid transfer line, the jacket unit, the heat transfer member, or the surface of the pipe, and that the heat is transferred to the fluid to be maintained in temperature. Therefore, even if the heater unit is installed in the tank or the fluid transfer line, the heating control in the present invention can be understood as a control for ultimately maintaining the temperature of the fluid to be maintained in temperature.

[0096] The SSR driver (400) corresponds to each of the plurality of heater units (300) and controls the power supply to the corresponding heater unit. When the SSR driver receives an ON control signal from the control unit (600), it causes power to be supplied to the corresponding heater unit, and when it receives an OFF control signal from the control unit (600), it causes the power supply to the corresponding heater unit to be cut off. The SSR driver may be a solid-state relay, an SSR module, a semiconductor switching circuit, a heater power control circuit, or a power control module. The SSR driver may be selected according to the rated voltage, rated current, power supply method, and load characteristics of the heater unit.

[0097] The ON control signal refers to a control signal output by the control unit (600) to control the SSR driver corresponding to a specific heater channel to a conduction state or a power supply allowance state. The OFF control signal refers to a control signal output by the control unit (600) to control the SSR driver corresponding to a specific heater channel to a cut-off state or a power supply cut-off state. The ON control signal and the OFF control signal may be provided in the form of a relay output, a digital output, a communication command, a control voltage applied to the SSR driving circuit, or an output state value inside the control unit (600).

[0098] The touch panel unit (500) displays a temperature input value, a set temperature value, an SSR control output status, a heater on command status, and an alarm status for each of the plurality of heater channels (900). The touch panel unit (500) may be an operation display device that allows a user to check the status of each heater channel and input a heater on command or a heater off command. The touch panel unit (500) may be an HMI, a touch screen, an industrial operation panel, a monitoring terminal, or a field operation panel.

[0099] The touch panel unit (500) can display, for each heater channel, the name or identification information of the fluid to be maintained at a certain temperature, the name or identification information of the tank in which the fluid to be maintained at a certain temperature is received, the name or identification information of the fluid transfer line in which the fluid to be maintained at a certain temperature is transferred, the temperature input value, the set temperature value, the lower limit control temperature value, the upper limit control temperature value, the heater on command status, the SSR control output status, the channel matching error alarm status, the heating delay alarm status, the heating delay candidate alarm status, the SSR diagnostic result, and the momentary power outage alarm information. When a channel matching error alarm occurs, the touch panel unit (500) can display the selected heater channel and the monitored heater channel together. Accordingly, the user can check which other heater channel's temperature input value has risen when attempting to heat a certain heater channel.

[0100] The control unit (600) generates a control signal for each of the plurality of SSR driving units (400) and alarm information displayed on the touch panel unit (500) using the temperature input value input through the temperature input unit (100) and the setting value stored in the setting value storage unit (200). The control unit (600) may be a PLC, a microcontroller, an embedded controller, an industrial computer, a logic controller, a distributed control unit, or a server-type control unit. The control unit (600) can execute program commands to perform temperature control processing, channel matching error determination processing, SSR diagnosis processing, heating delay determination processing, and power re-application or momentary power outage recovery processing.

[0101] The heater on command status, SSR control output status, and temperature input value are distinguished from one another. The heater on command status is a command status indicating whether the user has set the corresponding heater channel as an operation target. The SSR control output status is the status of the control signal that the control unit (600) is actually outputting to the SSR driver corresponding to the corresponding heater channel. The temperature input value is a temperature detection value input through the temperature input unit (100). Therefore, even when the heater on command status is in the ON state, if the temperature input value is greater than or equal to the upper limit control temperature value, an OFF control signal may be output to the corresponding SSR driver. Additionally, a heater channel in which the heater on command status is in the OFF state may be set as a monitored heater channel in channel matching error monitoring.

[0102] When a heater-on command for any one heater channel is input through the touch panel unit (500), the control unit (600) sets the heater-on command state of the corresponding heater channel to the ON state. The fact that the heater-on command state is ON means that the corresponding heater channel can be a temperature control target. However, just because the heater-on command state is ON does not mean that an ON control signal is always output to the SSR driver. The control unit (600) determines whether the temperature input value of the corresponding heater channel is below the lower control temperature value, above the upper control temperature value, or between the lower control temperature value and the upper control temperature value, and then determines the control signal for the SSR driver.

[0103] When a heater off command for any one heater channel is input through the touch panel unit (500), the control unit (600) sets the heater on command state of the corresponding heater channel to an off state and outputs an off control signal to the SSR driver corresponding to the corresponding heater channel. Accordingly, the heater channel for which the user input the heater off command is excluded from the temperature control target, and the power supply to the heater unit corresponding to the heater channel can be cut off.

[0104] The control unit (600) sets a heater channel among a plurality of heater channels (900) in which the heater on command state is on as a temperature control target heater channel. The control unit (600) performs temperature control processing for each temperature control target heater channel, and sets the heater channel on which temperature control processing is performed as a selected heater channel. Here, a selected heater channel refers to a heater channel that serves as a standard for temperature control processing, channel matching error monitoring processing, or diagnostic processing. When a plurality of heater channels (900) are set as temperature control target heater channels, the control unit (600) may process each heater channel sequentially as a selected heater channel, or may repeatedly perform control processing for each heater channel within a control cycle.

[0105] The control unit (600) outputs an ON control signal to the SSR drive unit corresponding to the select heater channel if the temperature input value of the select heater channel is lower than or equal to the lower limit control temperature value obtained by subtracting the lower limit error range of the select heater channel from the set temperature value of the select heater channel. In this case, since the temperature-maintaining fluid corresponding to the select heater channel is in a state lower than the target maintenance temperature, the control unit (600) controls the heater unit to supply power.

[0106] The control unit (600) outputs an off control signal to the SSR drive unit corresponding to the select heater channel if the temperature input value of the select heater channel is greater than or equal to the upper control temperature value obtained by adding the upper error range of the select heater channel to the set temperature value of the select heater channel. In this case, since the temperature-maintaining fluid corresponding to the select heater channel is in a state higher than the target maintenance temperature, the control unit (600) controls the power supply to the heater unit to be cut off.

[0107] The control unit (600) maintains the previous control signal for the SSR driver corresponding to the selected heater channel when the temperature input value of the selected heater channel exceeds the lower control temperature value and is less than the upper control temperature value. Maintaining the previous control signal may mean maintaining the on control signal or off control signal that was output to the corresponding SSR driver in the previous control cycle. Accordingly, even if the temperature input value fluctuates repeatedly around the set temperature value, the SSR driver may be turned on and off excessively frequently.

[0108] When the control unit (600) outputs an ON control signal to the SSR driver corresponding to the selected heater channel, it sets one or more heater channels among the remaining heater channels excluding the selected heater channel as the heater channel to be monitored, wherein the heater ON command state is OFF and an OFF control signal is output to the corresponding SSR driver. The heater channel to be monitored is a heater channel for which the user has not issued a heater ON command and the control unit (600) is also outputting an OFF control signal to the SSR driver corresponding to the heater channel. Therefore, under normal circumstances, the temperature input value of the heater channel to be monitored should not rise significantly due to the ON control signal output of the selected heater channel.

[0109] The control unit (600) sets the time at which it outputs an ON control signal to the SSR driver corresponding to the selected heater channel as the monitoring start time. At the monitoring start time, the control unit (600) stores the temperature input value of each monitored heater channel as a comparison reference temperature value. The comparison reference temperature value is a reference value for calculating the temperature rise of the monitored heater channel. Since each monitored heater channel may have a different temperature input value at the monitoring start time, the control unit (600) stores the comparison reference temperature value individually for each monitored heater channel.

[0110] The control unit (600) calculates the temperature increase amount by subtracting the comparison reference temperature value of the corresponding heater channel from the temperature input value of each heater channel under monitoring while an ON control signal is output to the SSR driver corresponding to the selected heater channel, the heater ON command state of the heater channel under monitoring is maintained in the OFF state, and an OFF control signal is output to the SSR driver corresponding to the heater channel under monitoring. The temperature increase amount of the heater channel under monitoring indicates how much the temperature input value of the heater channel under monitoring has increased since the start of monitoring.

[0111] The control unit (600) terminates the calculation of the temperature rise amount for the monitored heater channel when the ON control signal output for the SSR driver corresponding to the selected heater channel is terminated. This is to prevent temperature changes unrelated to the ON control signal output period of the selected heater channel from being reflected in the determination of channel matching errors. Subsequently, when the ON control signal is output again to the SSR driver corresponding to the selected heater channel, the control unit (600) sets a new monitoring start time, sets one or more monitored heater channels anew at the new monitoring start time, and stores the temperature input value of each newly set monitored heater channel as a new comparison reference temperature value.

[0112] A temperature rise threshold value for determining channel matching errors can be stored corresponding to a selected heater channel. In this case, the control unit (600) compares the temperature rise of the monitored heater channel with the temperature rise threshold value for determining channel matching errors stored corresponding to the selected heater channel during the monitoring period in which an ON control signal is output to the selected heater channel. Accordingly, even for the same monitored heater channel, different threshold values ​​may be applied depending on which selected heater channel's ON control signal output is monitored. For example, a selected heater channel corresponding to a temperature-maintaining fluid contained in a tank with a large heat capacity and a selected heater channel corresponding to a temperature-maintaining fluid transferred through a fluid transfer line with a small heat capacity may have different temperature rise threshold values ​​for determining channel matching errors.

[0113] The control unit (600) determines whether there is a channel matching error based on the ON control signal output of the selected heater channel by determining whether the temperature rise of any one of the monitored heater channels is greater than or equal to the channel matching error judgment temperature rise threshold value stored corresponding to the selected heater channel, and whether this state is maintained for longer than the channel matching error alarm delay time stored corresponding to the selected heater channel. The channel matching error judgment temperature rise threshold value is a threshold value for determining whether the rise in the temperature input value of the monitored heater channel is a rise sufficient to indicate the possibility of a channel matching error, rather than being due to simple sensor noise, ambient temperature changes, or temporary fluctuations. The channel matching error alarm delay time is a time value for filtering out cases where the state in which the temperature rise is greater than the threshold value occurs temporarily.

[0114] The control unit (600) determines that the temperature input value of the monitored heater channel has increased in response to the ON control signal output for the selected heater channel when the temperature rise amount of the monitored heater channel is greater than or equal to the channel matching error judgment temperature rise threshold value stored corresponding to the selected heater channel and is maintained for longer than the channel matching error alarm delay time stored corresponding to the selected heater channel. In this case, the control unit (600) generates a channel matching error alarm between the selected heater channel and the monitored heater channel.

[0115] The channel matching error alarm may include at least one of identification information of the selected heater channel, identification information of the monitored heater channel, the time of output of the on control signal for the selected heater channel, the start time of monitoring, a comparison reference temperature value, a temperature input value at the time of alarm occurrence, a temperature rise amount, a temperature rise reference value for determining the channel matching error, and a channel matching error alarm delay time. The touch panel unit (500) can display the selected heater channel and the monitored heater channel together where the channel matching error alarm occurred. Accordingly, the user can check which other heater channel's temperature input value has risen when attempting to heat a certain heater channel.

[0116] A channel matching error alarm may be related to a temperature sensor wiring error, a heater unit wiring error, an SSR driver unit wiring error, an input / output channel setting error of the control unit (600), a channel display error of the touch panel unit (500), a channel matching information error of the setting value storage unit (200), or an on-site construction error. For example, if an ON control signal is output to the SSR driver corresponding to the first heater channel, but the temperature input value of the first heater channel does not rise and the temperature input value of the second heater channel rises, there is a possibility that there is a channel matching error between the first heater channel and the second heater channel. In this case, the SSR output of the first heater channel may be connected to the second heater unit, the first temperature sensor input and the second temperature sensor input may be connected in reverse, or the channel display of the touch panel unit (500) may be inconsistent with the actual wiring.

[0117] To reduce misjudgment in determining channel matching errors, the control unit (600) considers together the ON control signal output state for the selected heater channel, the heater ON command state of the monitored heater channel, the OFF control signal output state of the SSR driver corresponding to the monitored heater channel, and the channel matching error alarm delay time. Therefore, rather than generating a channel matching error alarm based solely on the fact that the temperature input value of a specific heater channel has risen, the channel matching error can be determined when the conditions of the selected heater channel receiving a heating command and the monitored heater channel remaining in an OFF state are satisfied together. This method can reduce misjudgment caused by normal ambient temperature rise, process heat transfer, transient sensor noise, or natural temperature fluctuations.

[0118] The control unit (600) may switch the heater-on command status of the selected heater channel and the corresponding monitored heater channel to an off state when a channel matching error alarm is generated. This is to prevent the temperature-maintaining fluid from being continuously heated unintended by the user. After switching the heater-on command status of the selected heater channel and the monitored heater channel to an off state, the control unit (600) may output an off control signal to the SSR driver corresponding to the heater channels.

[0119] The control unit (600) can control the heater on command status of the heater channel to not be changed to the ON state even if a heater ON command for the selected heater channel or the monitored heater channel corresponding to the channel matching error alarm is input through the touch panel unit (500) until an administrator confirmation input and an alarm release input for the channel matching error alarm are input through the touch panel unit (500). The administrator confirmation input is an input indicating that the administrator has confirmed the alarm content, and the alarm release input may be an input to release the alarm state after wiring inspection, construction inspection, channel setting inspection, or sensor connection inspection. Accordingly, even if the user accidentally inputs the heater ON command again after the alarm occurs, it is possible to prevent reheating without inspection.

[0120] The control unit (600) can diagnose the heating response of a heater channel to which an ON control signal is output to the SSR drive unit. To this end, the setting value storage unit (200) can store an SSR inspection delay time, a first reference change amount, a second reference change amount, a temperature stagnation reference value, and a number of consecutive stagnation judgments for each heater channel. The SSR inspection delay time is the time observed while waiting after the ON control signal is output to determine whether the heater unit actually exhibits a heating effect. The first reference change amount is a reference value for determining how much the temperature input value must rise at least to be considered as a heating response. The second reference change amount is a reference value for determining whether the temperature input value has risen excessively, and the second reference change amount is set to a value greater than the first reference change amount. The temperature stagnation reference value is a reference amount for the temperature change between consecutive diagnosis points to be considered as stagnant. The number of consecutive stagnation judgments is a value that determines how many consecutive times the temperature change stagnates to be judged as a stagnation pattern.

[0121] The SSR check delay time is the time required to observe changes in the temperature input value of the heater channel itself after an ON control signal is output to the heater channel under diagnosis. On the other hand, the channel matching error alarm delay time is the time required to determine whether the rising state of the temperature input value of the monitored heater channel is maintained for a certain period of time or longer in response to the ON control signal output of the selected heater channel. Therefore, the SSR check delay time and the channel matching error alarm delay time are time values ​​with different judgment purposes and can be set identically or differently for each heater channel.

[0122] The first reference change amount refers to a reference value for determining how much the temperature input value of the heater channel under diagnosis must rise during the SSR inspection delay time after the ON control signal is output to the heater channel under diagnosis in order to be considered as having a heating response. The second reference change amount refers to a reference value for determining whether the temperature input value of the heater channel under diagnosis has risen excessively beyond the normal heating response range after the ON control signal is output to the heater channel under diagnosis. The second reference change amount may be set to a value greater than the first reference change amount.

[0123] The first abnormal cause candidate information, the second abnormal cause candidate information, and the third abnormal cause candidate information refer to different types of abnormal cause candidate information generated by the control unit (600) based on the result of distinguishing the pattern of the heating reaction. The first abnormal cause candidate information is information generated in response to a non-rising pattern, the second abnormal cause candidate information is information generated in response to a stagnant pattern, and the third abnormal cause candidate information is information generated in response to a rapid rise pattern. Here, the expressions "first," "second," and "third" are merely identification expressions to distinguish each abnormal cause candidate information from one another, and do not necessarily limit the importance, order of occurrence, or risk level of the abnormal cause.

[0124] The first candidate cause information may be generated when the temperature input value does not rise above a first reference change amount even though an ON control signal is output to the heater channel under diagnosis, and may include at least one of SSR non-operation, heater open circuit, possibility of circuit breaker off, or possibility of power supply abnormality. The second candidate cause information may be generated when the temperature input value of the heater channel under diagnosis rises above the first reference change amount and then the temperature rise stagnates, and may include at least one of insufficient heater capacity, increased fluid volume of the fluid to be maintained in the tank, increased flow rate of the fluid to be maintained in the tank through the fluid transfer line, or increased heat load. The third candidate cause information may be generated when the temperature input value of the heater channel under diagnosis rises above a second reference change amount, and may include at least one of miswiring or misinstallation of the temperature input system, insufficient fluid to be maintained in the tank, insufficient fluid to be maintained in the tank through the fluid transfer line, or an air-heating state of the heater unit.

[0125] The control unit (600) sets the heater channel to which an ON control signal is output to the corresponding SSR drive unit among the plurality of heater channels (900) as the heater channel to be diagnosed. The control unit (600) sets the time at which an ON control signal is output to the SSR drive unit corresponding to the heater channel to be diagnosed as the diagnosis start time, and stores the temperature input value of the heater channel to be diagnosed at the diagnosis start time as the diagnosis reference temperature value. The control unit (600) stores the temperature input values ​​input for each temperature detection time during the SSR inspection delay time of the heater channel to be diagnosed as a plurality of diagnosis temperature values ​​in chronological order.

[0126] The diagnostic temperature value refers to the temperature input value of the target heater channel for diagnosis that is input at each temperature detection point during the SSR inspection delay time after the start of diagnosis. Multiple diagnostic temperature values ​​can be stored in chronological order, and the control unit (600) can determine a non-rising pattern, a stagnant pattern, or a rapid rising pattern using the multiple diagnostic temperature values. The diagnostic reference temperature value refers to the temperature input value of the target heater channel for diagnosis at the start of diagnosis, and the control unit (600) can calculate the amount of temperature change by subtracting the diagnostic reference temperature value from each diagnostic temperature value.

[0127] The control unit (600) determines a non-rising pattern if the amount of temperature change obtained by subtracting the diagnostic reference temperature value from the diagnostic temperature value at the time when the SSR inspection delay time has elapsed is less than the first reference change amount of the diagnostic target heater channel. A non-rising pattern means a state in which the temperature input value does not rise sufficiently even though an ON control signal is output to the diagnostic target heater channel. A non-rising pattern may occur when the SSR driving unit does not actually operate, the heater unit is disconnected, the circuit breaker is in an OFF state, or power is not supplied to the heater unit. When a non-rising pattern is determined, the control unit (600) may generate first abnormal cause candidate information corresponding to at least one of the following: SSR non-operation, heater disconnection, circuit breaker OFF possibility, or power supply abnormality.

[0128] SSR non-operation may mean a state in which the SSR driver does not switch to a conduction state or a power supply allowance state even though the control unit (600) has output an ON control signal to the SSR driver corresponding to the heater channel to be diagnosed, or a state in which power is not supplied from the output side of the SSR driver to the heater unit. Heater disconnection may mean a state in which the heating wire or electrical resistor inside the heater unit is broken and current does not flow normally. Circuit breaker off possibility may mean a possibility in which the power breaker corresponding to the heater channel is in an OFF state or tripped state, so power is not delivered to the heater unit. Power supply abnormality possibility may mean a possibility in which the power voltage, current, phase power, or power supply path that should be supplied to the heater unit is not normal. In such a state, even if an ON control signal is output, the temperature input value of the fluid to be maintained does not rise sufficiently, so the control unit (600) can generate a non-rising pattern in conjunction with the first abnormal cause candidate information.

[0129] The control unit (600) determines a stagnation pattern if, after the temperature change amount obtained by subtracting a diagnostic reference temperature value from any one of the multiple diagnostic temperature values ​​stored during the SSR inspection delay time becomes greater than or equal to a first reference change amount, the number of consecutive diagnostic points is greater than or equal to the number of consecutive stagnation judgments, and the change amount relative to the previous diagnostic temperature value at each diagnostic point is within the temperature stagnation reference value. A stagnation pattern refers to a state in which the temperature input value initially rises but subsequently does not rise sufficiently and stagnates. A stagnation pattern may be associated with insufficient heater capacity, an increase in the volume of the fluid to be maintained in the tank, an increase in the flow rate of the fluid to be maintained transferred through the fluid transfer line, an increase in external heat loss, poor insulation, or an increase in process heat load. When a stagnation pattern is determined, the control unit (600) may generate second abnormal cause candidate information corresponding to at least one of insufficient heater capacity, an increase in the volume of the fluid to be maintained in the tank, an increase in the flow rate of the fluid to be maintained transferred through the fluid transfer line, or an increase in heat load.

[0130] Insufficient heater capacity may refer to a state where, even if the heater unit operates according to the ON control signal, the amount of heat generated by the heater unit is insufficient compared to the fluid volume, flow rate, viscosity, heat capacity, or process heat loss of the fluid to be maintained at a given temperature. An increase in the amount of fluid to be maintained at a given temperature within the tank may refer to a state where the amount of fluid that must be heated with the same amount of heat generated by the heater unit increases, causing the rate of temperature rise to decrease or the rate of temperature rise to stagnate. An increase in the flow rate of the fluid to be maintained at a given temperature conveyed through the fluid transfer line may refer to a state where the amount of fluid passing through the fluid transfer line increases, causing the heat supplied from the heater unit to move or disperse rapidly by the flow of the fluid. An increase in heat load may refer to a state where the amount of heat that the heater unit must supply increases due to a decrease in external temperature, a decrease in insulation performance, an increase in heat absorption by the process device, an increase in fluid viscosity, or an increase in the heat capacity of the fluid. In such a state, even if the temperature input value rises initially, the rate of subsequent rise may decrease or stagnate; therefore, the control unit (600) can generate a stagnation pattern in conjunction with second abnormal cause candidate information.

[0131] The control unit (600) determines a rapid rise pattern if the amount of temperature change obtained by subtracting the diagnostic reference temperature value from the maximum diagnostic temperature value among the multiple diagnostic temperature values ​​stored during the SSR inspection delay time exceeds a second reference change amount. A rapid rise pattern refers to a state in which the temperature input value rises faster than a normal heating response. A rapid rise pattern may be related to a miswiring or incorrect installation of the temperature input system, a shortage of the fluid to be maintained in the tank, a shortage of the fluid to be maintained transported through the fluid transfer line, or an air-heating state of the heater unit. An air-heating state of the heater unit may refer to a state in which the heater unit is heated while there is a shortage of the fluid to be maintained or the heat transfer target that the heater unit needs to heat. When a rapid rise pattern is determined, the control unit (600) may generate third abnormal cause candidate information corresponding to at least one of the miswiring or incorrect installation of the temperature input system, a shortage of the fluid to be maintained in the tank, a shortage of the fluid to be maintained transported through the fluid transfer line, or an air-heating state of the heater unit.

[0132] The reason why miswiring or incorrect installation of the temperature input system can be a candidate cause of a rapid rise pattern is that the temperature input value of the heater channel to be diagnosed may not represent the representative temperature of the fluid to be maintained at an actual temperature. For example, if the wiring of the temperature sensor corresponding to the heater channel to be diagnosed is connected to the temperature input terminal of another heater channel, or if the detection value of the temperature sensor corresponding to another heater channel is input as the temperature input value of the heater channel to be diagnosed, the control unit (600) may recognize a temperature rise at a location other than the fluid to be maintained at an actual temperature of the heater channel to be diagnosed as a temperature rise of the heater channel to be diagnosed. In addition, if the temperature sensor is installed at a location excessively close to the heater section, a local overheating location on the tank wall, a local heating location on the fluid transfer line, or a location with a large difference from the representative temperature of the fluid to be maintained at an actual temperature, the temperature input value may rise faster than a normal fluid temperature rise. Therefore, when a rapid rise pattern is determined, the control unit (600) may include miswiring or incorrect installation of the temperature input system as a third candidate cause.

[0133] The reason a shortage of the temperature-maintaining fluid within the tank can be a candidate cause of the rapid temperature rise pattern is that if the fluid volume inside the tank is insufficient, there is not enough fluid to absorb the heat generated by the heater, which can cause the temperature of the tank walls, the area around the heater, or the temperature sensor to rise rapidly. The reason a shortage of the temperature-maintaining fluid transported through the fluid transfer line can be a candidate cause of the rapid temperature rise pattern is that if the fluid flow inside the transfer line is insufficient or stopped, the heat generated by the heater cannot be sufficiently transported by the fluid flow and may become concentrated in specific sections. The reason an air-heating state of the heater can be a candidate cause of the rapid temperature rise pattern is that if the heater operates without being sufficiently thermally connected to the temperature-maintaining fluid being heated, the temperature around the heater or the temperature detected by the temperature sensor may rise faster than under normal fluid heating conditions.

[0134] The non-rising pattern, stagnation pattern, and rapid rise pattern are judgment classifications for estimating different causes of abnormality. When multiple pattern conditions are simultaneously satisfied in a single heater channel, the control unit (600) may prioritize displaying the pattern with a high risk or display multiple candidate abnormality causes together. For example, since the rapid rise pattern may be associated with air heating or a shortage of fluid for temperature maintenance, the control unit (600) may switch the heater on command status of the corresponding heater channel to an off state when the rapid rise pattern is determined, and display it as an alarm requiring immediate verification on the touch panel unit (500). However, the present invention is not limited to a specific pattern priority, and the display method may be changed according to field safety standards or user settings.

[0135] The control unit (600) can switch the heater on command status of the heater channel to be diagnosed, where the first abnormal cause candidate information, the second abnormal cause candidate information, or the third abnormal cause candidate information is generated, to an off state. Additionally, the control unit (600) can control the touch panel unit (500) to display the heater channel to be diagnosed, the temperature input value of the heater channel to be diagnosed, the SSR control output status of the heater channel to be diagnosed, and the abnormal cause candidate information. Accordingly, the user can check not only the fact that an abnormality has occurred in the heater channel, but also the item presumed to be the cause of the abnormality.

[0136] The control unit (600) can determine the heating delay. To this end, the setting value storage unit (200) can store a reference rise rate and a reference time for calculating the rise rate for each heater channel. The reference rise rate is a reference value for determining how much the temperature input value must rise above during the reference time for calculating the rise rate to be considered a normal heating response. The reference time for calculating the rise rate is the time for observing the temperature input value to calculate the temperature rise rate after the start of heating.

[0137] The control unit (600) sets the heater channel in which the heater on command state is set to the ON state as the heater channel for delay determination target. The control unit (600) sets the time when the heater on command state of the heater channel for delay determination target is set to the ON state as the heating start time, and stores the temperature input value of the heater channel for delay determination target at the heating start time as the heating start temperature value. If the heating start temperature value is less than the lower limit control temperature value obtained by subtracting the lower limit error range from the set temperature value of the heater channel for delay determination target, the control unit (600) calculates the difference in lower limit reached temperature by subtracting the heating start temperature value from the lower limit control temperature value.

[0138] The control unit (600) calculates the temperature rise rate of the heater channel subject to delay determination using the temperature input values ​​input at each temperature detection point during the rise rate calculation reference time after the heating start time. The temperature rise rate may be the value obtained by dividing the increase in the temperature input value during the rise rate calculation reference time by the rise rate calculation reference time. If the temperature rise rate is greater than or equal to the reference rise rate, the control unit (600) calculates the estimated time to reach the lower limit control temperature by dividing the difference in the lower limit reached temperature by the temperature rise rate.

[0139] The control unit (600) generates a heating delay alarm if the temperature input value of the heater channel subject to delay determination does not rise above the lower control temperature value from the start of heating until the expected time to reach the lower control temperature has elapsed. The heating delay alarm may include heating delay information including the expected time to reach the lower control temperature, the actual elapsed time, and the temperature input value of the heater channel subject to delay determination. If the temperature rise rate is less than the reference rise rate, the control unit (600) may generate a heating delay candidate alarm before calculating the expected time to reach the lower control temperature. The heating delay candidate alarm may be an alarm indicating that there is a possibility of future heating delays occurring because the temperature rise rate itself is low. When a heating delay candidate alarm is generated, the touch panel unit (500) may display heating delay candidate information including the actual elapsed time and the temperature input value of the heater channel subject to delay determination.

[0140] A heating delay candidate alarm is a preliminary alarm generated when the temperature rise rate during the rise rate calculation reference time is less than the reference rise rate, and a heating delay alarm may be a confirmed alarm generated when the temperature input value fails to rise above the lower control temperature value even after the estimated time to reach the calculated lower control temperature has elapsed. Therefore, the heating delay candidate alarm is intended to indicate the possibility of a heating delay early, while the heating delay alarm is intended to indicate a state where an actual delay in reaching the temperature has been confirmed. Accordingly, the user can identify the possibility of a heating delay early due to insufficient capacity of the heater unit, an increase in the volume of the fluid to be maintained, an increase in the flow rate, an increase in external heat loss, or changes in process conditions.

[0141] The power status input unit can receive the circuit breaker status and the overload relay status corresponding to each of the plurality of heater channels (900). The circuit breaker status may indicate the normal state, off state, trip state, or power cut-off state of the power circuit breaker corresponding to the corresponding heater channel. The overload relay status may indicate an overcurrent, overload, or protection operation state related to the heater unit or the SSR drive unit.

[0142] The sensor status input unit can receive the sensor error status of the temperature input system corresponding to each of the plurality of heater channels (900). The sensor error status may include a temperature sensor open circuit, a temperature sensor short circuit, an input range exceeded, a communication abnormality, an abnormal detection value, a temperature input module malfunction, or an undetectable state. Since the reliability of the temperature input value is low for a heater channel in which a sensor error status has occurred, the control unit (600) may maintain the heater on command status of the corresponding heater channel in an off state or limit automatic recovery.

[0143] The state storage unit may include a non-volatile memory that stores the heater-on command status of each of the plurality of heater channels (900). The state storage unit may be a storage means that maintains the stored state even after the power is cut off. The control unit (600) periodically stores the heater-on command status of each of the plurality of heater channels (900) in the state storage unit. Accordingly, even if a power cut or momentary power outage occurs, the control unit (600) can check whether each heater channel was in an ON state or an OFF state before the power cut off after power re-application or recovery from the momentary power outage.

[0144] The setting value storage unit (200) can store an automatic recovery setting value, an automatic recovery delay time, and a high temperature alarm reference value for each of the plurality of heater channels (900). The automatic recovery setting value is a value indicating whether to automatically restore the heater ON command state upon power re-application or recovery from a momentary power outage. The automatic recovery setting value can be set to an active state or an inactive state for each heater channel. The automatic recovery delay time is a time value for waiting until the temperature input value, sensor error state, circuit breaker state, and overload relay state are stably verified, without immediately restoring the heater ON command state after power re-application or recovery from a momentary power outage. The high temperature alarm reference value is a reference value for limiting automatic recovery when the temperature input value of the heater channel to be recovered is already high.

[0145] When the control unit (600) detects the re-application of power to the heating control system or the recovery of a momentary power outage, it checks the heater-on command status of each of the plurality of heater channels (900) stored in the state storage unit before the power cutoff as the heater operating state prior to the power outage. After the re-application of power or the recovery of a momentary power outage, the control unit (600) checks recovery judgment information for each of the plurality of heater channels (900), including temperature input values, sensor error status, circuit breaker status, and overload relay status.

[0146] The control unit (600) determines whether the recovery judgment information satisfies the recovery allowance conditions at the time when the automatic recovery delay time of the recovery target heater channel has elapsed, when the automatic recovery setting value of the recovery target heater channel, which is in the ON state before the power outage, is in the used state. The recovery allowance conditions may include the condition that the temperature input value of the recovery target heater channel entered at the time when the automatic recovery delay time has elapsed is less than the high temperature alarm threshold value of the recovery target heater channel, the condition that the sensor error state of the recovery target heater channel is released, the condition that the circuit breaker state of the recovery target heater channel is in a normal state, and the condition that the overload relay state of the recovery target heater channel is in a normal state.

[0147] The control unit (600) restores the heater on command state of the heater channel to be restored to the ON state when the restoration judgment information of the heater channel to be restored satisfies the restoration allowance condition. Conversely, if the automatic restoration setting value of the heater channel to be restored is in an unused state, the control unit (600) generates momentary power outage alarm information and maintains the heater on command state of the heater channel to be restored in the OFF state. In addition, even if the automatic restoration setting value is in an active state, if the temperature input value of the heater channel to be restored is greater than or equal to the high temperature alarm threshold value, or if the sensor error state is not released, or if the circuit breaker state or overload relay state is not in a normal state, the control unit (600) may maintain the heater on command state of the heater channel to be restored in the OFF state.

[0148] Even if the automatic recovery setting value is in use, if any of the recovery allowance conditions are not satisfied, the control unit (600) may not restore the heater on command state of the recovery target heater channel to the on state and may maintain it in the off state. In this case, the control unit (600) may generate at least one of an automatic recovery limit alarm, a high temperature recovery cutoff alarm, a sensor error recovery cutoff alarm, a circuit breaker abnormal recovery cutoff alarm, or an overload relay abnormal recovery cutoff alarm. Accordingly, the heater unit may be prevented from automatically restarting immediately after power re-application or recovery from a momentary power outage when the temperature input value is excessively high, the reliability of the temperature input system is low, or the power system is not in a normal state.

[0149] The momentary power outage alarm information may include at least one of the heater channel in which the heater on command state was ON before the power cut-off, the automatic recovery setting value, whether automatic recovery was performed, the reason why automatic recovery was restricted, the temperature input value at the time of recovery determination, the sensor error state, the circuit breaker state, and the overload relay state. The touch panel unit (500) displays the momentary power outage alarm information so that the user can check which heater channel was automatically recovered and which heater channel remained in the OFF state after power re-application or recovery from the momentary power outage.

[0150] The heating control system can be applied when multiple temperature-maintaining fluids are all contained in a tank, when multiple temperature-maintaining fluids are all transferred through a fluid transfer line, or when some temperature-maintaining fluids are contained in a tank and other temperature-maintaining fluids are transferred through a fluid transfer line. It can also be applied when multiple tanks (700) and multiple fluid transfer lines (800) are managed together within a single process facility.

[0151] The heating control system is not limited to a specific numerical range, a specific type of temperature sensor, a specific type of heater, or a specific type of SSR drive unit. The set temperature value, lower error range, upper error range, temperature rise threshold value for determining channel matching error, channel matching error alarm delay time, SSR inspection delay time, first threshold change amount, second threshold change amount, temperature stagnation threshold value, number of consecutive stagnation judgments, threshold rise rate, threshold time for calculating rise rate, automatic recovery delay time, and high temperature alarm threshold value may be set differently depending on the type of fluid to be maintained, the viscosity of the fluid to be maintained, the flow rate of the fluid to be maintained, the capacity of the heater unit, the heat loss of the equipment, process conditions, and safety standards.

[0152] The heating control system determines the correlation between the output of the ON control signal for the selected heater channel and the rise in the temperature input value of the monitored heater channel. Accordingly, rather than generating an alarm based solely on the fact that the temperature input value of a specific heater channel has risen, it can determine channel matching errors by considering both the time when the selected heater channel receives a heating command and the condition under which the monitored heater channel remains in the OFF state.

[0153] The heating control system manages the heater ON command status, SSR control output status, and temperature input values ​​separately, and performs temperature control, determines channel matching errors, diagnoses SSRs, detects heating delays, and processes power re-application or momentary power outage recovery based on the setpoints and status values ​​for each heater channel. Accordingly, in facilities handling multiple temperature-maintaining fluids, risks such as miswiring between heater channels, incorrect installation, setting discrepancies, heater response abnormalities, heating delays, and restart risks during recovery can be systematically managed.

[0155] A heating control system according to another embodiment of the present invention stores thermal response fingerprint information indicating the temperature change characteristics during normal heating for each of a plurality of heater channels (900), and can determine the cause of an abnormality in a heater channel by comparing the temperature change characteristics measured during actual operation with the thermal response fingerprint information.

[0156] The heating control system according to the other embodiment above may further include a thermal response fingerprint storage unit that stores thermal response fingerprint information for each of a plurality of heater channels (900). The thermal response fingerprint information may be information indicating a normal time response characteristic in which the temperature input value changes after an ON control signal is output to an SSR driving unit corresponding to the heater channel. The thermal response fingerprint information may include at least one of an initial rise delay time, a time to reach a reference rise amount, a temperature rise amount within a reference time, a maximum rise rate, an average rise rate, a time point for the rise rate to decrease, a time point for the occurrence of a temperature stagnation section, a duration of the temperature stagnation section, and a temperature drop rate after the output of an OFF control signal.

[0157] The initial rise delay time may refer to the time from when an ON control signal is output to the SSR driver corresponding to the heater channel under diagnosis until the temperature input value of the heater channel under diagnosis rises above a preset minimum rise amount. The reference rise amount arrival time may refer to the time from when the ON control signal is output until the temperature input value of the heater channel under diagnosis reaches a preset reference rise amount. The maximum rise rate may refer to the largest temperature rise rate among multiple temperature rise rates calculated during a preset observation time after the ON control signal is output. The average rise rate may be the value obtained by dividing the increase in the temperature input value during the observation time by the observation time. The rise rate decrease point may be the point at which the temperature rise rate begins to decrease below a preset rate after reaching the maximum rise rate. The temperature plateau section may be a section in which the amount of change relative to the previous diagnosis temperature value at multiple consecutive diagnosis points remains within the temperature plateau reference value. The temperature drop rate after the OFF control signal output may be a value indicating the degree to which the temperature input value decreases after the OFF control signal is output to the SSR driver corresponding to the heater channel.

[0158] Thermal response fingerprint information can be generated during pre-shipment testing, commissioning after installation, verification operation after maintenance, or in a stable state during normal operation. The control unit (600) outputs an ON control signal to an SSR driver corresponding to a specific heater channel, collects temperature input values ​​of the heater channel in chronological order during a preset fingerprint generation time, and calculates at least one of an initial rise delay time, a reference rise amount arrival time, a maximum rise rate, an average rise rate, a rise rate decrease point, a temperature stagnation period, and a temperature drop rate after outputting an OFF control signal from the collected temperature input values, and stores it as thermal response fingerprint information of the heater channel.

[0159] Thermal response fingerprint information can be stored differently for each heater channel. A heater channel corresponding to a temperature-maintaining fluid contained in a tank may have relatively mild thermal response fingerprint information depending on the fluid volume, tank capacity, tank material, heater section capacity, and insulation condition. A heater channel corresponding to a temperature-maintaining fluid transferred through a fluid transfer line may have thermal response fingerprint information different from that of the tank depending on the flow rate, pipe length, pipe diameter, installation length of the heater section, and insulation condition. Therefore, the control unit (600) does not apply the same standard to all heater channels, but can determine whether there is an abnormality based on the normal thermal response fingerprint information for each heater channel.

[0160] The control unit (600) can set one of the plurality of heater channels (900) as the heater channel for fingerprint comparison during actual operation. After an ON control signal is output to the SSR driver corresponding to the heater channel for fingerprint comparison, the control unit (600) can collect temperature input values ​​of the heater channel for fingerprint comparison in chronological order during a preset fingerprint comparison time, and calculate actual thermal response information from the collected temperature input values. The actual thermal response information may include at least one of the actual initial rise delay time, the actual time to reach the reference rise amount, the actual maximum rise rate, the actual average rise rate, the actual rise rate decrease point, the actual temperature stagnation period, and the actual temperature drop rate after turning off.

[0161] The control unit (600) can calculate a thermal response deviation value by comparing the actual thermal response information of the fingerprint comparison target heater channel with the thermal response fingerprint information stored corresponding to the fingerprint comparison target heater channel. The thermal response deviation value may include at least one of the difference between the actual initial rise delay time and the stored initial rise delay time, the difference between the actual reference rise amount arrival time and the stored reference rise amount arrival time, the difference between the actual maximum rise rate and the stored maximum rise rate, the difference between the actual average rise rate and the stored average rise rate, the difference between the actual temperature stagnation period and the stored temperature stagnation period, or the difference between the actual temperature drop rate after off and the stored temperature drop rate after off.

[0162] The control unit (600) can determine that the heating response of the fingerprint comparison target heater channel is within the normal thermal response range if the thermal response deviation value is within the preset fingerprint allowable deviation value. Conversely, if the thermal response deviation value exceeds the fingerprint allowable deviation value, the control unit (600) can determine that the heating response of the fingerprint comparison target heater channel is outside the normal thermal response range and generate a thermal response fingerprint deviation alarm.

[0163] The control unit (600) can generate different candidate information for abnormal causes depending on the occurrence pattern of the thermal response deviation value. For example, if the actual initial rise delay time is longer than the stored initial rise delay time and the actual average rise rate is lower than the stored average rise rate, the control unit (600) can generate candidate information for abnormal causes corresponding to at least one of the following: heater unit performance degradation, heater capacity insufficient, SSR drive unit output degradation, circuit breaker contact abnormality, power supply abnormality, or thermal load increase.

[0164] The control unit (600) can generate candidate information for abnormal causes corresponding to at least one of an increase in the fluid volume of the fluid to be maintained at temperature, an increase in the flow rate of the fluid to be maintained at temperature transferred through the fluid transfer line, an increase in external heat loss, poor insulation, or an increase in process heat load, when the actual initial rise delay time is within the normal range but the duration of the actual temperature stagnation section is longer than the duration of the stored temperature stagnation section or the actual rise rate decrease point is earlier than the stored rise rate decrease point.

[0165] The control unit (600) can generate candidate information for abnormal causes corresponding to at least one of the following: a shortage of fluid to be maintained at temperature inside the tank, a shortage of fluid to be maintained at temperature transferred through the fluid transfer line, an error in the installation location of the temperature sensor, a mis-construction of the temperature input system, or an air-heating state of the heater unit, when the actual maximum rise rate is greater than the stored maximum rise rate and the actual time to reach the reference rise amount is shorter than the time to reach the stored reference rise amount.

[0166] The control unit (600) can generate a candidate for a channel matching error between the heater channel to be compared with the fingerprint comparison target and another heater channel when, even though an ON control signal is output to the SSR driver corresponding to the heater channel to be compared with the fingerprint comparison target, the actual thermal response information of the heater channel to be compared with the stored thermal response fingerprint information is significantly different, and at the same time, a temperature change similar to the stored thermal response fingerprint information appears in the temperature input value of another heater channel. In this case, the control unit (600) can generate a candidate for a channel matching error by comparing whether the temporal shape of the temperature rise curve is similar to the thermal response fingerprint information of which heater channel, rather than simply comparing only the amount of temperature rise.

[0167] The control unit (600) can calculate a similarity score for each heater channel to compare the thermal response fingerprint information for each of the plurality of heater channels (900) with the actual thermal response information. The similarity score can be calculated as higher as the deviation between the actual thermal response information and the stored thermal response fingerprint information is smaller. If the actual thermal response information of the heater channel subject to fingerprint comparison has a higher similarity score with the thermal response fingerprint information of another heater channel than with the thermal response fingerprint information of the heater channel subject to fingerprint comparison, the control unit (600) can generate a channel matching error candidate between the heater channel subject to fingerprint comparison and the other heater channel.

[0168] The control unit (600) can switch the heater on command state of the corresponding fingerprint comparison target heater channel to an off state when a thermal response fingerprint deviation alarm or a channel matching error candidate is generated. Additionally, the control unit (600) can control the touch panel unit (500) to display information regarding the fingerprint comparison target heater channel, thermal response deviation value, similarity score, thermal response fingerprint deviation alarm, channel matching error candidate, and abnormal cause candidate.

[0169] The control unit (600) can update the thermal response fingerprint information only when there is an administrator approval input, even after the thermal response fingerprint information has been generated. For example, the existing thermal response fingerprint information may differ from the actual normal state after replacing the heater unit, replacing the temperature sensor, replacing the tank, changing the fluid transfer line, replacing the insulation material, or changing the process conditions. In this case, the control unit (600) performs a fingerprint update mode after the administrator approval input and can update the thermal response fingerprint information using the newly collected temperature input value in the fingerprint update mode.

[0170] The control unit (600) can compare the thermal response fingerprint information prior to update with the thermal response fingerprint information candidate for update even when the fingerprint update mode is performed. If the thermal response fingerprint information candidate for update differs from the thermal response fingerprint information prior to update by exceeding a preset update allowable deviation value, the control unit (600) can restrict the automatic update of the thermal response fingerprint information and generate an administrator confirmation alarm. Accordingly, it is possible to prevent thermal response information collected in an actual abnormal state from being incorrectly stored as normal thermal response fingerprint information.

[0171] According to the present embodiment, the control unit (600) is not limited to controlling whether the temperature input value is lower or higher than the set temperature value, but can determine whether the response characteristics of the heater channel itself have deviated from the normal range by comparing the normal thermal response fingerprint information for each heater channel with the actual thermal response information. In addition, the control unit (600) can distinguish and generate candidates for heater unit performance degradation, increased heat load, insufficient fluid to maintain temperature, incorrect construction of the temperature input system, air heating state of the heater unit, or channel matching error based on the deviation form between the thermal response fingerprint information and the actual thermal response information. Accordingly, in a heating control system including a plurality of heater channels (900), wiring errors, construction errors, fluid state abnormalities, and heater performance abnormalities that are difficult to identify through simple temperature control can be determined early.

[0173] A heating control system according to another embodiment of the present invention can determine the possibility of solidification, crystallization, increased viscosity, or decreased fluidity of a fluid to be maintained at a temperature, and change the control conditions of a heater channel according to the possibility.

[0174] The heating control system according to the above-described other embodiment may further include a fluid characteristic storage unit that stores fluid characteristic information of a fluid to be maintained at a temperature corresponding to each of a plurality of heater channels (900). The fluid characteristic information may include at least one of a solidification reference temperature, a viscosity increase reference temperature, a crystallization reference temperature, a fluidity decrease reference temperature, a temperature drop allowance time, a reheat allowance time, and a maintenance priority of the fluid to be maintained at a temperature.

[0175] The control unit (600) can calculate the risk of phase change for each of the plurality of heater channels (900) using a temperature input value, a set temperature value, and fluid characteristic information. The risk of phase change may be a value indicating the possibility that the fluid to be maintained at a temperature will reach a state of solidification, crystallization, increased viscosity, or decreased fluidity.

[0176] The control unit (600) can set a heater channel as a phase change risk heater channel even if the temperature input value of one heater channel is higher than the set temperature value of the heater channel, if the temperature input value of the heater channel approaches a solidification reference temperature, a viscosity increase reference temperature, a crystallization reference temperature, or a fluidity decrease reference temperature, and the temperature decrease rate is greater than or equal to the reference decrease rate.

[0177] The control unit (600) can output an ON control signal to the SSR drive unit corresponding to the phase change risk heater channel, temporarily reduce the lower limit error range of the corresponding phase change risk heater channel, or increase the lower limit control temperature value based on the set temperature value. Accordingly, heating of the heater unit can be preceded before the temperature-maintained fluid actually reaches a state of solidification, crystallization, or viscosity increase.

[0178] When two or more of the plurality of heater channels (900) are simultaneously set as phase change risk heater channels, the control unit (600) can adjust the heating order or heating holding time of the heater units based on the holding priority stored in the fluid characteristic storage unit. The holding priority can be set in order of the likelihood that the fluid to be maintained at temperature will solidify or increase in viscosity, thereby causing process stoppage, line blockage, poor cleaning, or equipment damage.

[0179] The control unit (600) can release the phase change risk state for the corresponding phase change risk heater channel when the temperature input value of the phase change risk heater channel rises above the phase change risk release temperature value. The phase change risk release temperature value can be set to a value higher than the solidification standard temperature, viscosity increase standard temperature, crystallization standard temperature, or fluidity decrease standard temperature.

[0180] The control unit (600) can generate a phase change risk alarm if the state in which the phase change risk level is greater than or equal to the reference risk level is maintained for longer than the phase change risk alarm delay time. The phase change risk alarm may include identification information of the corresponding heater channel, the type of fluid to be maintained at temperature, a temperature input value, a solidification reference temperature, a viscosity increase reference temperature, a crystallization reference temperature, a fluidity decrease reference temperature, a temperature drop rate, and a phase change risk level.

[0181] According to the present embodiment, the control unit (600) does not merely control the heater unit based on the difference between the set temperature value and the temperature input value, but can also pre-control the heating of the heater unit based on the possibility of solidification, crystallization, increased viscosity, or decreased fluidity of the fluid to be maintained at temperature. Accordingly, it is possible to suppress the solidification or decreased flowability of the chemical liquid, liquid, viscous fluid, or process liquid with the potential for crystallization.

[0183] Although embodiments of the present invention have been described in more detail with reference to the attached drawings, the present invention is not necessarily limited to these embodiments and may be modified in various ways within the scope of the technical spirit of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not limit, the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of protection of the present invention shall be interpreted by the claims below, and all technical spirits within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention.

[0184] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims set forth below. Explanation of the symbols

[0186] 100 : Temperature input section 200 : Setting value storage 300 : Multiple heater units 400 : Multiple SSR drivers 500 : Touch panel section 600 : Control unit 700 : Multiple tanks 800: Multiple fluid transfer lines 900: Multiple heater channels

Claims

Claim 1 In a heating control system for maintaining the temperature of a plurality of temperature-maintaining fluids, each of the plurality of temperature-maintaining fluids is contained in a tank or transported through a fluid transport line, and a heater channel is set corresponding to the tank containing each of the plurality of temperature-maintaining fluids or the fluid transport line being transported, and a temperature input unit receives a temperature input value corresponding to the temperature at the time of temperature detection of the temperature-maintaining fluid contained in the tank or transported through the fluid transport line corresponding to each of the plurality of heater channels; a setting value storage unit that stores, for each of the plurality of heater channels, a set temperature value corresponding to the target maintenance temperature of the corresponding temperature-maintaining fluid, a lower error range based on the set temperature value, an upper error range based on the set temperature value, a temperature rise reference value for determining channel matching error, and a channel matching error alarm delay time; a plurality of heater units corresponding to each of the plurality of heater channels and heating the temperature-maintaining fluid contained in the corresponding tank or transported through the corresponding fluid transport line; a plurality of SSR driving units corresponding to each of the plurality of heater units and controlling the power supply to the corresponding heater units; and for each of the plurality of heater channels, temperature detection A touch panel unit that displays a temperature input value corresponding to the temperature at a given point in time, a set temperature value corresponding to the target maintenance temperature, an SSR control output status, a heater on command status, and an alarm status, and receives a heater on command or a heater off command for each of the plurality of heater channels; and a control unit that generates a control signal for each of the plurality of SSR driving units and alarm information displayed on the touch panel unit by using the temperature input value input through the temperature input unit, the set temperature value stored in the set value storage unit, a lower error range, an upper error range, a temperature rise reference value for determining channel matching error, and a channel matching error alarm delay time.A heating control system comprising: a heater channel among the plurality of heater channels in which the heater on command state is on as a selected heater channel; when an on control signal is output to an SSR driver corresponding to the selected heater channel, one or more heater channels among the remaining heater channels excluding the selected heater channel in which the heater on command state is off and an off control signal is output to a corresponding SSR driver are set as monitored heater channels; and when it is determined that the temperature input value of any one of the monitored heater channels has increased in response to the on control signal output for the selected heater channel, a channel matching error alarm is generated between the selected heater channel and any one of the monitored heater channels. Claim 2 In claim 1, the control unit sets the heater on command state of any one heater channel among the plurality of heater channels to an ON state when a heater ON command for any one heater channel is input through the touch panel unit, sets the heater on command state of any one heater channel to an OFF state when a heater OFF command for any one heater channel among the plurality of heater channels is input through the touch panel unit, outputs an OFF control signal to an SSR driver corresponding to any one heater channel, outputs an ON control signal to an SSR driver corresponding to the select heater channel if the temperature input value of the select heater channel is less than or equal to a lower control temperature value obtained by subtracting the lower error range of the select heater channel from the set temperature value of the select heater channel, outputs an ON control signal to an SSR driver corresponding to the select heater channel if the temperature input value of the select heater channel is greater than or equal to an upper control temperature value obtained by adding the upper error range of the select heater channel to the set temperature value of the select heater channel, and outputs an OFF control signal to an SSR driver corresponding to the select heater channel if the temperature input value of the select heater channel exceeds the lower control temperature value and is less than the upper control temperature value. In the case of a heating control system that maintains an immediate control signal for an SSR drive unit corresponding to the selected heater channel. Claim 3 In claim 1, the control unit sets the time at which an ON control signal is output to an SSR driver corresponding to the selected heater channel as the monitoring start time; at the monitoring start time, for each of the monitored heater channels, the temperature input value at the monitoring start time is stored as a comparison reference temperature value; while an ON control signal is output to an SSR driver corresponding to the selected heater channel, the heater ON command state of the monitored heater channel is maintained in an OFF state, and an OFF control signal is output to an SSR driver corresponding to the monitored heater channel, the temperature rise amount is calculated by subtracting the comparison reference temperature value of the corresponding monitored heater channel from the temperature input value of each of the monitored heater channels; when the output of the ON control signal to the SSR driver corresponding to the selected heater channel ends, the calculation of the temperature rise amount for the monitored heater channel ends; when an ON control signal is output again to an SSR driver corresponding to the selected heater channel, a new monitoring start time is set, one or more monitored heater channels are newly set at the new monitoring start time, and the temperature input value of each of the newly set monitored heater channels is stored as a new comparison reference temperature value, and the selected heater In order to determine whether there is a channel matching error based on the ON control signal output of a channel, if the temperature rise of any one of the monitored heater channels is greater than or equal to the channel matching error judgment temperature rise threshold value stored corresponding to the selected heater channel and this condition is maintained for longer than the channel matching error alarm delay time stored corresponding to the selected heater channel, it is determined that the temperature input value of any one of the monitored heater channels has risen in response to the ON control signal output for the selected heater channel, and a channel matching error alarm is generated between the selected heater channel and any one of the monitored heater channels, and when the channel matching error alarm is generated,A heating control system that switches the heater-on command status of the selected heater channel and any one of the monitored heater channels to an off state, and controls the heater-on command status of the corresponding heater channel not to change to an on state even if a heater-on command for the selected heater channel or any one of the monitored heater channels corresponding to the channel matching error alarm is input through the touch panel unit until an administrator confirmation input and an alarm release input regarding the channel matching error alarm are input through the touch panel unit.

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