CN218824563U

CN218824563U - Current monitoring logic control circuit and system

Info

Publication number: CN218824563U
Application number: CN202221802334.7U
Authority: CN
Inventors: 袁继鹏
Original assignee: Cangzhou China Resources Thermal Power Co Ltd
Current assignee: Cangzhou China Resources Thermal Power Co Ltd
Priority date: 2022-07-13
Filing date: 2022-07-13
Publication date: 2023-04-07
Anticipated expiration: 2032-07-13

Abstract

The utility model discloses a current monitoring logic control circuit and system belongs to electric tracing technical field, and logic control circuit includes: the temperature detection module is used for detecting the environmental temperature of the electric tracing system and outputting a temperature detection signal; the first operation module is used for obtaining a delay time length signal according to the temperature detection signal and a preset broken line function; the current acquisition module is used for acquiring the current value flowing in a current line of the electric tracing system; a current comparison module for judging whether the current value meets a preset threshold value and outputting a judgment result; a timing module for dynamically monitoring the receiving time length when the judgment result is yes and outputting a current alarm instruction when the receiving time length reaches the delay time length corresponding to the delay time length signal; and the alarm module is used for carrying out alarm prompt according to the current alarm instruction. The utility model provides a problem that can't in time discover when there is the trouble in the electric heat tracing system of the thermal control measurement station setting of current thermal power factory, reach high-efficient, reliably and in time discover the effect of electric heat tracing system trouble.

Description

Current monitoring logic control circuit and system

Technical Field

The utility model relates to an electric tracing technical field, in particular to current monitoring logic control circuit and system.

Background

The electric tracing system is an integral system which is formed by designing proper electric tracing materials and heat-insulating materials, matching relevant electric requirements and being installed and debugged. An electric tracing system is generally arranged at a thermal control measuring point of a thermal power plant and is mainly used for preventing freezing of the thermal control measuring point in winter.

Most of the current electric tracing systems are provided with independent controllers for displaying the current condition of the electric tracing systems. When the staff detects and patrols, the staff needs to check on the spot at the electric tracing system, manually check the current condition and make a judgment. The problem that exists in this kind of mode is, it is difficult to guarantee the timeliness of fault handling, may lead to the current abnormal condition not in time to be found, and cause bigger incident.

SUMMERY OF THE UTILITY MODEL

The utility model discloses a main aim at: the utility model provides a current monitoring logic control circuit and system, when aiming at solving the electric tracing system that the thermal control measurement station of current thermal power factory set up and has the trouble, the problem that can't in time discover.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

in a first aspect, the present invention provides a current monitoring logic control circuit, the logic control circuit includes:

the temperature detection module is used for detecting the environmental temperature of the electric tracing system and outputting a temperature detection signal;

the first operation module is connected with the temperature detection module and used for obtaining a delay time length signal according to the temperature detection signal and a preset broken line function and outputting the delay time length signal;

the current acquisition module is used for acquiring the current value flowing in a current line of the electric tracing system;

the current comparison module is connected with the current acquisition module and used for judging whether the current value meets a preset threshold value or not and outputting a judgment result;

the timing module is respectively connected with the current comparison module and the first operation module and is used for dynamically monitoring the receiving time length when the judgment result is yes and outputting a current alarm instruction when the receiving time length reaches the delay time length corresponding to the delay time length signal;

and the alarm module is connected with the timing module and used for carrying out alarm prompt according to the current alarm instruction.

Optionally, in the current monitoring logic control circuit, the current collecting module includes:

the current transmitter is used for collecting current flowing in a current line of the electric tracing system to obtain an alternating current signal, converting the alternating current signal and outputting a direct current signal;

and the signal converter is respectively connected with the current transmitter and the current comparison module, and is used for carrying out analog quantity conversion on the direct current signal to obtain a current value and outputting the current value to the current comparison module.

Optionally, in the current monitoring logic control circuit, the current comparing module includes:

the high-low comparator is connected with the current acquisition module and used for judging whether the current value meets a preset low limit threshold value and a preset high limit threshold value respectively and outputting two comparison results respectively;

and the logic AND is connected with the high-low comparator and used for performing logic AND processing on the two comparison results to obtain a final judgment result of the current value and outputting the judgment result.

Optionally, in the current monitoring logic control circuit, the first operation module includes:

the function generator is connected with the temperature detection module and used for obtaining delay time according to the temperature detection signal and a preset broken line function;

and the adapter is respectively connected with the function generator and the timing module and used for generating a delay time length signal according to the delay time length and outputting the delay time length signal to the timing module.

Optionally, in the current monitoring logic control circuit, the timing module includes:

and the timer is respectively connected with the timing module and the adapter and is used for receiving the delay time length signal, adjusting a built-in delay parameter to be the delay time length according to the delay time length signal, dynamically monitoring the receiving time length when the judgment result is yes, and outputting a current alarm instruction when the receiving time length reaches the delay time length.

Optionally, in the above current monitoring logic control circuit, the electric tracing system includes a first heating device disposed inside the on-site equipment and a second heating device disposed outside the on-site equipment;

the current collecting module is further configured to collect a first current value flowing in a current line of the first heating device and a second current value flowing in a current line of the second heating device;

the logic control circuit further comprises:

the second operation module is connected with the current acquisition module and used for obtaining a total current value according to the first current value and the second current value and outputting the total current value;

the current comparison modules are connected with the second operation module and used for comparing the total current value with a plurality of different preset thresholds and outputting corresponding judgment results;

the plurality of timing modules are connected with the plurality of current comparison modules in a one-to-one correspondence mode and used for correspondingly outputting the current alarm instruction according to the received judgment result.

Optionally, in the current monitoring logic control circuit, the logic control circuit further includes:

the fault diagnosis module is used for carrying out fault diagnosis on the electric tracing system and outputting a fault alarm instruction;

the logic or module is respectively connected with the plurality of timing modules and the fault diagnosis module and is used for carrying out logic or processing on the current alarm instruction and the fault alarm instruction and outputting the processed alarm instruction;

and the alarm module is also connected with the logic OR module and is used for carrying out alarm prompt according to the processed alarm instruction.

the plurality of first operation modules are connected with the temperature detection module, connected with the plurality of timing modules in a one-to-one correspondence manner, and used for respectively outputting the plurality of delay time length signals to the corresponding timing modules.

Optionally, in the above current monitoring logic control circuit, the multiple different preset thresholds include preset thresholds corresponding to when only the first heating device works, when only the second heating device works, when both the first heating device and the second heating device work, and when neither the first heating device nor the second heating device works.

In a second aspect, the present invention further provides a current monitoring system, the current monitoring system is connected to the electric heat tracing system disposed at the thermal control measuring point of the thermal power plant, and the current monitoring system includes a current monitoring logic control circuit as mentioned above.

The utility model provides an above-mentioned one or more technical scheme can have following advantage or at least realized following technological effect:

the utility model provides a current monitoring logic control circuit and system, through adopting the ambient temperature that temperature detection module detected electric heat tracing system, output temperature detected signal, obtain time length signal when delaying by first operation module according to temperature detected signal and preset broken line function, obtain the data foundation of fault diagnosis; when the electric tracing system works, the current value flowing in a current line of the electric tracing system is collected through the current collection module, whether the current value meets a preset threshold value is judged through the current comparison module, a judgment result is output, the receiving time when the judgment result is yes is dynamically monitored through the timing module, the receiving time reaches the delay time corresponding to the delay time signal, the electric tracing system is determined to have faults, a current alarm instruction is output, the alarm module is enabled to alarm according to the current alarm instruction, and a worker is timely informed, so that the electric tracing faults are timely found. After the utility model is applied to each thermal control measuring point of the thermal power plant, special staff is not needed to patrol, the waste of human resources can be reduced, and the working efficiency is higher; the utility model discloses combine ambient temperature with long time parameter, it is long when utilizing the time delay that the broken line function reachs, make the electric current control have corresponding and reliability more, realized high-efficient, reliable and in time discover the effect of electric tracing system trouble.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

Fig. 1 is a schematic connection diagram of a first embodiment of the current monitoring logic control circuit of the present invention;

fig. 2 is a schematic connection diagram of a second embodiment of the current monitoring logic control circuit of the present invention;

fig. 3 is a schematic connection diagram of a third embodiment of the current monitoring logic control circuit of the present invention;

fig. 4 is a signal transmission example diagram of a third embodiment of the current monitoring logic control circuit of the present invention.

The objects, features and advantages of the present invention will be further described with reference to the accompanying drawings.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that, in the present invention, the terms "comprises", "comprising" or any other variation thereof are intended to cover a non-exclusive inclusion, so that a device or system including a series of elements includes not only those elements but also other elements not explicitly listed or inherent to such a device or system. Without further limitation, an element defined by the phrases "comprising 8230; \8230;" 8230; "does not exclude the presence of additional like elements in a device or system that comprises the element. In the present application, unless expressly stated or limited otherwise, the terms "connected" and "fixed" are to be construed broadly, e.g., "connected" may be a fixed connection or a removable connection, or may be integral therewith; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium; either internally or in interactive relation. In the present invention, if there is a description referring to "first", "second", etc., the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicit indication of the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the present invention, suffixes such as "module", "part", or "unit" used to denote elements are used only for facilitating the description of the present invention, and have no specific meaning by themselves. Thus, "module", "component" or "unit" may be used mixedly.

The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art. In addition, the technical solutions of the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent, and is not within the protection scope of the present invention.

The analysis of the prior art shows that most of the current electric tracing systems are provided with independent controllers for displaying the current conditions of the electric tracing systems. Because the existing electric tracing system does not interact with a DCS (distributed control system) of a thermal control measuring point, when a worker detects and patrols, the worker needs to check the electric tracing system on site, manually check the current condition and make a judgment. The problem that this kind of mode exists is that detection efficiency is lower, is difficult to ensure data validity and the promptness of fault handling, and the condition that probably leads to the current anomaly is not found in time, and causes bigger incident.

In view of the electric heat tracing system that thermal power factory's thermal control measurement station set up among the prior art when having the trouble, the technical problem that can't in time discover, the utility model provides a current monitoring logic control circuit and system, concrete embodiment and implementation are as follows:

example one

Referring to fig. 1, fig. 1 is a schematic connection diagram of a first embodiment of the current monitoring logic control circuit of the present invention; the present embodiment provides a current monitoring logic control circuit. The logic control circuit may include:

The logic control circuit can be applied to a DCS system interacting with an electric tracing system, and the DCS system gives an alarm; the method can also be applied to independent current monitoring systems which are respectively interacted with the electric tracing system and the DCS, when alarm prompt is carried out, the alarm prompt can be directly carried out in the current monitoring system, signals related to the alarm prompt can be sent to the DCS, and prompt is carried out by the DCS.

Specifically, the electric tracing system may be an electric tracing system provided in any scene, for example, an electric tracing system provided at a thermal control point of a thermal power plant. In the logic control circuit, a temperature detection module can be a temperature sensor or a temperature measuring resistor and other devices and is used for detecting the external environment temperature of the electric tracing system to obtain a temperature detection signal; the preset broken line function in the first operation module can be directly set by a worker, and when the temperature detection module works, after receiving a temperature detection signal, the value of the environmental temperature contained in the temperature detection signal is directly substituted into the broken line function to obtain corresponding delay time length and generate a delay time length signal containing the delay time length; the current acquisition module acquires a current circuit of the electric tracing system, specifically, the current acquisition module acquires a value of current flowing through a heating device of the electric tracing system or a current circuit corresponding to the heating circuit to obtain a current value analog quantity, and the current value analog quantity is input to the current comparison module; the current comparison module extracts a current value corresponding to the current value analog quantity, judges whether a preset threshold value is met or not, the preset threshold value can be directly set by a worker, when the current value meets the preset threshold value, when the output judgment result is yes (indicated as 1 in a logic control circuit), the signal is output to the timing module, the timing module starts timing when receiving the signal, and when the judgment result is no (indicated as 0 in the logic control circuit), the timing module does not work; the timing module dynamically monitors the receiving time length of the received signal 1, continuously times, receives a delay time length signal output by the first operation module, changes the delay parameter of the timing module to the delay time length calculated by the first operation module, and then outputs a current alarm instruction when the timed receiving time length reaches the delay time length, at the moment, the current value in the electric tracing system is shown to be in an unreasonable range (a preset threshold value) for a long time (the time corresponding to the delay time length), the situation is generally caused by the fault of the electric tracing system, namely, the electric tracing system at the moment is very likely to have the fault; and finally, the alarm module carries out alarm prompt according to the current alarm instruction to remind workers of paying attention to the fact that the current value of the electric tracing system is abnormal and the workers need to go to the electric tracing system for processing in time. Therefore, the logical operation of the current value of the electric tracing system is realized, and the monitoring and alarming of the working condition of the electric tracing system are provided.

In the current monitoring logic control circuit of the embodiment, the temperature detection module is adopted to detect the environmental temperature of the electric heat tracing system, the temperature detection signal is output, and the first operation module obtains the time delay duration signal according to the temperature detection signal and the preset broken line function to obtain the data basis of fault judgment; when the electric tracing system works, the current value flowing in a current line of the electric tracing system is collected through the current collection module, whether the current value meets a preset threshold value is judged through the current comparison module, a judgment result is output, the receiving time when the judgment result is yes is dynamically monitored through the timing module, the receiving time reaches the delay time corresponding to the delay time signal, the electric tracing system is determined to have faults, a current alarm instruction is output, the alarm module is enabled to alarm according to the current alarm instruction, and a worker is timely informed, so that the electric tracing faults are timely found. After the utility model is applied to each thermal control measuring point of the thermal power plant, special staff is not needed to patrol, the waste of human resources can be reduced, and the working efficiency is higher; the utility model discloses combine ambient temperature and long time parameter, it is long when utilizing the time delay that the broken line function reachs, make the electric current control have more corresponding and reliability, realized high-efficient, reliable and in time discover the effect of electric tracing system trouble.

Example two

Referring to fig. 2, fig. 2 is a schematic connection diagram of a second embodiment of the current monitoring logic control circuit of the present invention; on the basis of the first embodiment, the present embodiment further provides a current monitoring logic control circuit.

Further, the current collection module may include:

the current transducer is used for collecting current flowing in a current line of the electric tracing system to obtain an alternating current signal, converting the alternating current signal and outputting a direct current signal;

and the signal converter is respectively connected with the current transmitter and the current comparison module and is used for carrying out analog quantity conversion on the direct current signal to obtain a current value and outputting the current value to the current comparison module.

Specifically, when the current transducer collects current flowing in a current line, a current value signal in the form of an alternating current signal is obtained, the current transducer can convert the alternating current signal into a direct current signal, for example, a current value signal in the form of a direct current signal of 4-20mA, and then output the direct current signal to the signal converter, perform analog quantity conversion, convert the direct current signal into a current value signal in the form of an alternating current analog quantity, and obtain a current value, and output the current value to the current comparison module for current abnormality judgment.

Further, the current comparison module may include:

the high-low comparator is connected with the current acquisition module and used for judging whether the current value meets a preset low-limit threshold value and a preset high-limit threshold value respectively and outputting two comparison results respectively;

When the current comparison module is used for judging current abnormity, different low alarm values and high alarm values can be set for different thermal control measuring points, namely different preset low limit threshold values and different preset high limit threshold values, and current abnormity is judged to exist only when two conditions are met in the high-low comparator through logic and realization. For example, when the current value is kept between 1 and 2 for a certain time, the electric tracing system is considered to have a fault, aiming at the setting, the preset low limit threshold value of the high-low comparator can be set to be 2, the preset high limit threshold value is set to be 1, if the acquired current value is 1.5, the current value 1.5 reaches the high alarm value 1 and is also lower than the low alarm value 2, the high-low comparator can output two 1 signals, and the current abnormality can be judged to exist at the moment by combining the logical and the logical and output 1; if the collected current value is 3, the current value 3 reaches the high alarm value 1, but is not lower than the low alarm value 2, the high-low comparator can only output a 1 signal and a 0 signal, and the current abnormality can be judged not to exist at the moment by combining the logical AND and the logical AND output 0, so that the final judgment result related to the current abnormality can be obtained to be 1 or 0.

Further, the first operation module may include:

Specifically, the method performs a fold line function operation on the external environment temperature of the electric tracing system to obtain a delay time length parameter related to current alarm of the electric tracing system at the heat control measuring point, so that the maximum bearable time length parameter, namely the delay time length, under abnormal current conditions in the timing module can be set according to the external environment temperature or the heat tracing environment temperature of different heat control measuring points, instead of directly determining whether to alarm or not by the default of the timing module or the parameter set by the timing module, thereby having more pertinence. The input of the function generator is a temperature detection signal containing ambient temperature, the preset broken line function can be a function of the change relation of the ambient temperature along with the maximum duration parameter of the abnormal current value corresponding to the electric tracing system at the thermal control measuring point, generally, the preset broken line function is directly set in advance by workers, the maximum duration parameter meeting the change relation is directly output, the maximum duration parameter corresponding to the ambient temperature is used as an operation result, namely, delay duration, then, in the adapter, a delay duration signal containing the delay duration is generated and output to the timing module, and the parameter of the timing module is subjected to adaptive adjustment.

Still further, the timing module may include:

and the timer is respectively connected with the timing module and the adapter and is used for receiving the delay time length signal, adjusting the built-in delay parameter to be the delay time length according to the delay time length signal, dynamically monitoring the receiving time length when the judgment result is yes, and outputting a current alarm instruction when the receiving time length reaches the delay time length.

For example, when the built-in delay parameter is 10 seconds, the timer receives a 1 signal sent by the current comparison module to start timing, and the 1 signal is still received after 10 seconds, so that the current abnormal condition of the electric tracing system at the moment is considered to exist, and the timing module generates a current alarm instruction and outputs the current alarm instruction. It can be understood that the built-in time delay parameter can also be directly timed in sequence, and the current alarm instruction is directly generated when the timing is reached. And combining the judgment result with the delay time to realize that the alarm instruction is output when the delay time is reached after the current meets the alarm value.

The current monitoring logic control circuit of the embodiment is characterized in that a current transmitter is arranged on an electric tracing system at a heat control measuring point to be monitored, analog quantity of a current value is obtained and sent to a current comparison module, a time delay duration parameter with abnormal current value is obtained by combining with the environment temperature, logic judgment is carried out on the result of current value comparison, an alarm instruction with abnormal current is output, a current monitoring function is realized, and when fault conditions such as tripping and heating equipment damage occur to the electric tracing system at the heat control measuring point, an alarm prompt is sent out to remind a worker to pay attention so as to enable the overhaul and maintenance personnel to take necessary measures in time and prevent abnormal events from further expanding.

EXAMPLE III

Referring to fig. 3, fig. 3 is a schematic connection diagram of a third embodiment of the current monitoring logic control circuit of the present invention; on the basis of the first embodiment or the second embodiment, the present embodiment further provides a current monitoring logic control circuit.

Further, the electric tracing system may include a first heating apparatus disposed inside the on-site apparatus and a second heating apparatus disposed outside the on-site apparatus;

the current acquisition module can be further used for acquiring a first current value flowing in a current circuit of the first heating device and a second current value flowing in a current circuit of the second heating device;

the logic control circuit may further include:

the current comparison modules are connected with the second operation module and are used for comparing the total current value with a plurality of different preset thresholds and outputting corresponding judgment results;

and the timing modules are correspondingly connected with the current comparison modules one by one and used for correspondingly outputting current alarm instructions according to the received judgment results.

In the current collection module, a current transformer and a signal converter may be correspondingly arranged for the condition of the heating device, as shown in the signal transmission example diagram of fig. 4, the current value of the first heating device and the current value of the second heating device are respectively collected by two current transformers, and the first current value and the second current value are correspondingly obtained. The first current value and the second current value are both current values of 4-20mA direct current signals, and the signal converters correspondingly connected with the two current transmitters can adopt sensors of AIS/FBS type to convert the current values of the 4-20mA direct current signals into current values of analog quantity to participate in subsequent logic operation. It can be understood that, in practical applications, the number of the heating devices may be increased, and the number of the collected current values may be correspondingly increased in response to the increase of the number of the heating devices.

The second operation module can adopt an adder sigma (I) to perform summation operation on the input current value so as to input the current value to the current comparison module for current abnormity judgment. Here the adder sigma (I) is a two-input adder. It will be appreciated that in practice the input to the adder may be multiple input, when there are multiple heating devices.

When the current comparison module judges the current abnormity, different low alarm values and high alarm values, namely different preset low limit threshold values and different preset high limit threshold values, can be set for different working states of the thermal control measuring point in the plurality of current comparison modules. For example, when the thermal control measurement point has two heating devices inside the local device and outside the local device, the two heating devices generally operate at different current values, and for this situation, a preset low-limit threshold and a preset high-limit threshold may be set in one of the current comparison modules when only one of the heating devices operates, and a preset low-limit threshold and a preset high-limit threshold may be set when neither of the two heating devices operates.

When different high-low comparators and logic and devices are adopted for abnormality judgment in different working states, the timing module also needs to correspondingly set different time parameter judgment standards so as to perform current abnormality judgment and fault determination more specifically.

Still further, the logic control circuit may further include:

The fault diagnosis module can be a fault recognizer which is set for other devices in an electric heat tracing system or a logic control circuit, outputs a fault alarm instruction in the form of a switching value signal, and is connected with the logic or module together with the timers in the plurality of timing modules, so that the fault diagnosis module can directly alarm as long as any fault condition or other fault problems in different working states exist.

Still further, the logic control circuit may further include:

and the first operation modules are connected with the temperature detection modules, correspondingly connected with the timing modules one by one and used for respectively outputting the time delay signals to the corresponding timing modules.

The preset broken line function of the function generator in each first operation module can be different, so that the delay time duration under different working states can be calculated for one environment temperature, and the delay time duration can be used on different timers. As shown in the signal transmission example diagram of fig. 4, three function generators in three first operation modules all receive the temperature detection signal of the same ambient temperature, can obtain three different delay duration parameters, and output the three different delay duration parameters to the adapters ADAPT connected correspondingly; the adapter ADAPT has a function of modifying parameters of other functional code devices, and the adapter ADAPT herein can modify parameters of the timer TD-DIG connected thereto, specifically, modify the delay parameter built therein.

Furthermore, the plurality of different preset thresholds include preset thresholds corresponding to when only the first heating device is operated, when only the second heating device is operated, when both the first heating device and the second heating device are operated, and when neither the first heating device nor the second heating device is operated.

As shown in fig. 4, the electric tracing system at a certain thermal control measuring point of the thermal power plant is monitored for current. Assuming that a first heating device is arranged inside the on-site equipment of the thermal control measuring point, and a second heating device is arranged outside the on-site equipment, the heat tracing of instrument pipelines inside and outside the box is respectively realized, assuming that the rated current of the first heating device during the independent operation is 1.4, the rated current of the second heating device during the independent operation is 1.93, the rated current of the second heating device during the independent operation is 3.33, the rated current of the second heating device during the independent operation is 0, and the actually detected current value can have a deviation of about 0.3. The current monitoring logic control circuit corresponding to fig. 4 may be configured to determine that certain three states corresponding to the heating device do not last too long, and if the three states are kept for a certain time, it indicates that the automatic heating set by the electric tracing system has a failure, and thus maintenance is required.

Aiming at the setting, current values are respectively acquired through a current transducer and a signal converter to respectively obtain a first current value and a second current value, the first current value and the second current value are input into an adder sigma (I), and a total current value is obtained through summation; the total current value is then input into three different current comparison modules, respectively.

Assuming that the high value and the low value of the high-low comparator H/L in the first current comparison module are 1.2 and 1.6 respectively, when the total current value is greater than the high value 1.2 and less than the low value 1.6, the situation that the first heating device works and the second heating device does not work can be judged; assuming that the high value of the high-low comparator H// L in the second current comparison module is 1.8 and the low value is 4, when the total current value is greater than the high value 1.8 and less than the low value 4, it can be determined that the second heating device is working, the first heating device is not working and the first heating device and the second heating device are both working, and it is assumed that the abnormal delay parameters corresponding to the two conditions are the same, so that a group of current comparison modules and corresponding subsequent devices can be reduced to save the whole logic determination process; if the high value of the high-low comparator H/L in the third current comparison module is-0.5 and the low value thereof is 0.5, when the total current value is greater than the high value of-0.5 and less than the low value of 0.5, the situation that the first heating device and the second heating device do not work can be judged; for example, assuming that the obtained total current value is 0.005, when the total current value is input into the three current comparison modules, only the high-low comparator in the third current comparison module satisfies the conditions of high value AND low value at the same time, the high-low comparator outputs two 1 signals at the same time, AND gives the subsequent logical AND, the logical AND receives the two 1 signals, the 1 signal will be output, AND if the received 1 signal AND 0 signal, the 1 signal will not be output.

The logic AND outputs a 1 signal to a corresponding timer TD-DIG, a delay parameter in the timer TD-DIG is the delay time contained in a delay time signal output by an adapter ADAPT connected with the timer TD-DIG, the timer TD-DIG starts to time after receiving the 1 signal, AND when the time reaches the delay time, the timer TD-DIG outputs a 1 signal, which indicates that at the moment, the first heating device AND the second heating device do not work for a certain time, a current abnormal condition exists, AND an electric tracing system possibly has equipment faults.

The logic OR module receives the outputs of the three timers TD-DIG and the output of the fault diagnosis module, wherein the outputs of the first timer TD-DIG, the second timer TD-DIG and the fault diagnosis module are all 0, only the output of the third timer TD-DIG is 1, and the logic OR module outputs a 1 signal, namely an alarm instruction, as long as the logic OR module receives the 1 signal; after the alarm module receives the alarm instruction of the signal 1, alarm prompt can be carried out, so that a user can know the fault condition that the electric tracing system has current abnormity in time.

The fault conditions of the electric tracing system shown in the example are that the time for independently heating the interior of the local equipment cannot exceed the time length of A, and if the time length exceeds the time length of A, the local equipment is regarded as a fault; the time for heating the outside of the on-site equipment independently or heating the inside and the outside of the on-site equipment together cannot exceed the time length of B, and if the time length of B exceeds the time length of B, the on-site equipment is regarded as a fault; the time for which the inside and the outside of the on-site equipment are not heated can not exceed the time length of C, and if the time length exceeds the time length of C, the equipment is regarded as a fault; and other faults of the electric tracing system detected by the fault diagnosis module, such as abnormal power failure, current transducer faults arranged on the electric tracing system, and the like. In practical applications, different working states may be set for specific situations, and current monitoring may be performed based on the different working states, so that connection relationships of more groups of devices of different numbers may be set, and specific connection relationships may refer to fig. 3 and fig. 4, which are not described herein again.

The current monitoring logic control circuit of the embodiment judges whether the current is abnormal by applying the characteristic that the current generally fluctuates when the circuit normally works and does not stay in one state for too long time, and judges whether the current is abnormal or not by judging whether the current stays in one state for too long time, so that whether the electric tracing system is in fault or not is alarmed, the logic judgment principle is simple, the connection structure is not complex, and the current abnormity monitoring and alarm prompt of the electric tracing system comprising a plurality of heating devices can be realized only by some simple logic devices.

Example four

The embodiment provides a current monitoring system which can be connected with an electric tracing system arranged at a thermal control point of a thermal power plant, and the current monitoring system can comprise a current monitoring logic control circuit.

The current monitoring system can be a subsystem in a DCS (distributed control system) in which thermal control measuring points of a thermal power plant are located, interaction between the electric tracing system and the DCS is realized, and an alarm of the DCS is directly called when alarm prompt is carried out, so that a worker can conveniently monitor the thermal control measuring points and monitor the electric tracing system at the thermal control measuring points; the current monitoring system can also be a peer system which is independent of the DCS and connected with the DCS, alarm instructions are sent to the DCS while alarm prompting is carried out, alarm prompting is respectively carried out, linkage alarm between the two systems is achieved, and the condition that the alarm is missed by workers is avoided.

The specific structure of the current monitoring logic control circuit refers to the above embodiments, and since this embodiment adopts all technical solutions of all the above embodiments, all beneficial effects brought by the technical solutions of the above embodiments are at least achieved, and are not described in detail herein.

It should be noted that the numbers of the embodiments of the present invention are merely for description, and do not represent the merits of the embodiments. The above is only the optional embodiment of the present invention, and not therefore the limit of the patent scope of the present invention, all the concepts of the present invention utilize the equivalent structure transformation of the content of the specification and the attached drawings, or directly or indirectly applied to other related technical fields, all included in the patent protection scope of the present invention.

Claims

1. A current monitoring logic control circuit, the logic control circuit comprising:

the current acquisition module is used for acquiring the value of current flowing in a current line of the electric tracing system;

the timing module is respectively connected with the current comparison module and the first operation module and is used for dynamically monitoring the receiving time when the judgment result is yes and outputting a current alarm instruction when the receiving time reaches the delay time corresponding to the delay time signal;

2. The current monitoring logic control circuit of claim 1, wherein the current collection module comprises:

3. The current monitoring logic control circuit of claim 1, wherein the current comparison module comprises:

4. The current monitor logic control circuit of claim 1, wherein the first operational block comprises:

5. The current monitor logic control circuit of claim 4, wherein the timing module comprises:

6. The current monitoring logic control circuit of claim 1, wherein the electric trace heating system comprises a first heating device disposed inside the on-site equipment and a second heating device disposed outside the on-site equipment;

the current collection module is further used for collecting a first current value flowing in a current circuit of the first heating device and a second current value flowing in a current circuit of the second heating device;

the logic control circuit further comprises:

7. The current monitor logic control circuit according to claim 6, wherein said logic control circuit further comprises:

8. The current monitoring logic control circuit of claim 6, wherein the logic control circuit further comprises:

9. The current monitoring logic control circuit of claim 6, wherein the plurality of different preset thresholds include preset thresholds corresponding to when only the first heating device is operating, when only the second heating device is operating, when both the first heating device and the second heating device are operating, and when neither the first heating device nor the second heating device is operating.

10. An electric current monitoring system connected to an electric tracing system provided at a thermal control point of a thermal power plant, the electric current monitoring system comprising an electric current monitoring logic control circuit according to any one of claims 1 to 9.