A remote monitoring system for the status of a self-limiting temperature heating belt

Abstract

The present invention provides a remote monitoring system for the status of a self-limiting temperature heating tape, comprising: a heating tape power distribution control device, multiple self-limiting temperature heating tapes, a PLC acquisition device, and a monitoring host. The self-limiting temperature heating tape is installed on the pipeline to be heated, with a current transformer at one end and a temperature sensor at the other end. The acquisition device connects the current transformer and the temperature sensor to respectively acquire the current in the self-limiting temperature heating circuit and the temperature signal on the pipeline surface, which are then transmitted to the monitoring host. The self-limiting temperature heating tape is connected to the heating tape power distribution control device, which is in turn connected to the monitoring host. The heating tape power distribution control device controls the start or stop of the self-limiting temperature heating tape based on the pipeline surface temperature. The present invention can relatively accurately determine various types of heating tape faults, such as short circuit faults, disconnection faults, and heating element failures. Operators can remotely monitor the operating status of the heating tape and promptly identify faulty heating tapes, providing reliable protection.

Description

Technical Field

[0001] The present invention relates to the field of remote fault diagnosis, and in particular to a remote monitoring system for the status of a self-limiting temperature heating belt for outdoor pipelines in high-altitude cold areas. Background Art

[0002] Self-limiting temperature heating cables can automatically heat the pipeline according to the ambient temperature to keep the pipeline within a certain temperature range. However, when the heating cable fails or is disconnected, if the fault cannot be discovered in time, the pipeline will be frozen and damaged. The existing monitoring method is to determine whether the heating cable is faulty by whether the power supply circuit breaker is tripped. This method can only judge faults caused by short circuits, and cannot judge faults such as disconnections or failure of heating elements. For outdoor pipelines in high-altitude and cold areas, there is a very high demand for insulation, including GIL pipelines of distribution devices, temperature-sensitive chemical raw material pipelines, fire water pipes and other pipelines that need to be heated. Once the heating cable breaks, the operation and maintenance personnel cannot discover and eliminate the heating cable fault in time, which will lead to reduced electrical insulation of the pipeline or ice damage, causing significant economic losses and even serious social impacts.

[0003] As the temperature of the self-limiting temperature heating cable rises, its loop current will decrease accordingly. When the ambient temperature changes greatly, the current will also change greatly. Therefore, it is impossible to determine whether the heating cable has a broken wire problem based on its working current, especially a broken wire at the tail. Summary of the Invention

[0004] In response to the problems existing in the existing technology, a self-limiting temperature heating belt status remote monitoring system is provided. It uses the "similar ratio difference principle" as the main criterion and optimizes the layout of temperature sensors to accurately judge the short circuit fault and line break fault of the heating belt. The operating status of the heating belt can be monitored in real time through remote automatic alarm. When a fault occurs, the operation and maintenance personnel are reminded to promptly discover and repair the faulty heating belt, thereby ensuring production safety and avoiding major economic losses.

[0005] The technical solution adopted by the present invention is as follows: a remote monitoring system for the status of a self-limiting temperature heating tape, comprising: a heating tape power distribution control device, multiple self-limiting temperature heating tapes, a PLC acquisition device and a monitoring host; the self-limiting temperature heating tape is arranged on the pipeline to be heated, and a current transformer is arranged at one end thereof, and a temperature sensor is arranged at the other end thereof; the PLC acquisition device connects the current transformer and the temperature sensor to respectively collect the current of the self-limiting temperature heating circuit and the temperature signal of the pipeline surface, and then transmits them to the monitoring host; the self-limiting temperature heating tape is connected to the heating tape power distribution control device, and the monitoring host is connected to the heating tape power distribution control device, and the self-limiting temperature heating tape is controlled to start or stop according to the temperature of the pipeline surface through the heating tape power distribution control device.

[0006] Furthermore, the heating tape power distribution control device includes a PLC controller, multiple contactors and a power supply. The PLC controller is respectively connected to the multiple contactors to control the closing or opening of the contactor contacts; each contactor corresponds to a self-limiting temperature heating tape, and the self-limiting temperature heating tape is connected to the power supply through the contactor.

[0007] Furthermore, the monitoring host receives the collected temperature signal, and when the temperature is lower than the set first lower limit value, sends an instruction to the PLC controller to control the contactor contacts to close and start the self-limiting temperature heating tape heating; when the temperature value is higher than the set upper limit value, sends an instruction to the PLC controller to control the contactor contacts to open and stop the self-limiting temperature heating tape heating.

[0008] Furthermore, when the temperature received by the monitoring host is lower than a second lower limit value, it indicates that there is a fault in the self-limiting temperature heating tape and an alarm signal is issued; wherein, the second lower limit value is smaller than the first lower limit value.

[0009] Furthermore, the monitoring host is set with a heating tape loop fault current setting value. When the collected current is greater than the setting value, it is determined that a short circuit fault occurs in the corresponding heating tape.

[0010] Furthermore, the monitoring host also determines whether the self-limiting temperature heating tape has a disconnection fault or a heating element failure by comparing the current and length ratio difference of the adjacent self-limiting temperature heating tape, and issues an alarm when a fault occurs.

[0011] Furthermore, the specific method for comparing the current and length ratio difference of adjacent self-limiting temperature heating belts is:

[0012] For adjacent self-limiting temperature heating tapes 1 and 2, calculate their current-to-length ratio difference: Kd1 = |I1 / L1 - I2 / L2|; where I1 is the current of the self-limiting temperature heating tape 1 circuit, and L1 is the length of self-limiting temperature heating tape 1; I2 is the current of the self-limiting temperature heating tape 2 circuit, and L2 is the length of self-limiting temperature heating tape 2. Calculate the average current-to-length ratio: Kd = (I1 / L1 + I2 / L2) / 2. When Kd1 > |I1 / L1 - Kd| or Kd1 > |I2 / L2 - Kd|, a fault alarm signal is issued for the corresponding self-limiting temperature heating tape.

[0013] Furthermore, an air circuit breaker is provided between the contactor and the power supply for short circuit or overcurrent protection.

[0014] Compared with existing technologies, the above-mentioned technical solution offers the following advantages: it can more accurately identify various faults in self-limiting heating cables, such as short circuits, disconnections, and heating element failures. Operators can remotely monitor the operating status of the heating cables, enabling timely detection and repair of faulty ones. This provides a reliable guarantee for ensuring production safety and avoiding significant economic losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram of the remote monitoring system for the self-limiting temperature heating tape proposed by the present invention. DETAILED DESCRIPTION

[0016] The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar modules or modules with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications, and equivalents that fall within the spirit and scope of the appended claims.

[0017] like Figure 1 This embodiment proposes a remote monitoring system for the status of a self-limiting temperature heating cable to meet the needs of outdoor pipelines in cold and high-altitude areas with high insulation requirements, including GIL pipelines for power distribution devices, temperature-sensitive chemical raw material pipelines, fire water pipes, and other pipelines that require heating. The specific solution is as follows:

[0018] The system includes: a heating tape power distribution control device, multiple self-limiting temperature heating tapes, a PLC acquisition device and a monitoring host; the self-limiting temperature heating tapes are set on the pipeline to be heated, and each self-limiting temperature heating tape is equipped with a current transformer at one end for measuring the heating tape loop current, and a temperature sensor at the other end for the temperature of the pipeline surface to realize automatic startup of the heating tape.

[0019] The PLC acquisition device is connected to the current transformer and temperature sensor through the I / O board. At the same time, the analog signals collected by the current transformer and temperature sensor are received through the optical cable and monitored, and converted into corresponding digital signals. The collected signals are then transmitted to the monitoring host through optical fiber.

[0020] The self-limiting temperature heating tape is connected to the heating tape power distribution control device, and the monitoring host is connected to the heating tape power distribution control device. The heating tape power distribution control device controls the start or stop of the self-limiting temperature heating tape according to the temperature of the pipeline surface.

[0021] Specifically, the heating cable power distribution control device includes a PLC controller, multiple contactors, and a power supply. The PLC controller is connected to each of the contactors to control the closing or opening of the contactors. Each contactor corresponds to a self-limiting temperature heating cable, which is connected to the power supply via a contactor. In a preferred embodiment, an air circuit breaker is installed between the contactor and the power supply for short-circuit and overcurrent protection.

[0022] In this embodiment, the specific process of starting or stopping the self-limiting temperature heating tape is as follows: the monitoring host receives the collected temperature signal, and when the temperature is lower than the set first lower limit, it sends a command to the PLC controller to control the contactor contacts to close and start the self-limiting temperature heating tape heating; when the temperature value is higher than the set upper limit, it sends a command to the PLC controller to control the contactor contacts to open and stop the self-limiting temperature heating tape heating; when the measured temperature is lower than the set second lower limit, it indicates that the heating tape is not working properly, which can be used as a backup measure for line break monitoring;

[0023] Among them, the set second lower limit value, first lower limit value and upper limit value can be adjusted according to the actual situation on site, including the temperature range that the medium in the pipeline can withstand and the influence of ambient temperature; the second lower limit value < first lower limit value < upper limit value.

[0024] The temperature sensor is used to measure the ambient temperature of the outer surface of the pipeline. Although the current monitoring is real-time, the current of the heating cable will change slightly with the difference in the environment, and there will be a certain error. In order to improve reliability, a temperature sensor is installed at the end of the heating pipeline to monitor the temperature of the tail end of the heating cable as a backup measure. That is, when the temperature received by the monitoring host is lower than the second lower limit value, it indicates that there is a fault in the self-limiting temperature heating cable and an alarm signal is issued.

[0025] Furthermore, the monitoring host is set with a heating tape loop fault current setting value. When the collected current is greater than the setting value, it is determined that a short circuit fault has occurred in the corresponding heating tape.

[0026] A current sensor is installed at the head of each heating cable branch, connected in series with the heating cable loop, to monitor the loop current in real time. Since the current in self-limiting heating cables decreases as temperature rises and becomes relatively stable after 36 hours of operation, the operating current value still varies with ambient temperature. This makes it difficult to accurately determine whether a cable is broken or its heating element is malfunctioning based on the current of a single heating cable. When two identical heating cables are used in similar environments, their heating power and current per unit length are similar. Therefore, comparing the current-to-length ratio of adjacent heating cables can be used to determine whether a cable is broken or its heating element is malfunctioning.

[0027] Specifically, the specific method for comparing the current and length ratio difference of adjacent self-limiting temperature heating belts is:

[0028] Heating tape current-to-length ratio: K=I / L; I is the heating tape loop current, and L is the heating tape length.

[0029] For adjacent heating cables 1 and 2, calculate their current-to-length ratio difference: Kd1 = |I1 / L1-I2 / L2|; where I1 is the current of heating cable 1 circuit, and L1 is the length of heating cable 1; I2 is the current of heating cable 2 circuit, and L2 is the length of heating cable 2;

[0030] Calculate the average current-length ratio: Kd = (I1 / L1+I2 / L2) / 2, heating cable operation criterion: I1>0 or I2>0;

[0031] Since two identical heating cables have similar heating power and current per unit length under similar environmental conditions, theoretically, I1 / L1 = I2 / L2 = Kd. However, if one of the cables is broken or the heating element is not working, the current will drop significantly, and I1 / L1, I2 / L2, and Kd will become unequal. Therefore, the fault determination logic for heating cable 1 is: when Kd1 > |I1 / L1 - Kd|, a heating cable 1 fault alarm is issued. The fault determination logic for heating cable 2 is: when Kd1 > |I2 / L2 - Kd|, a heating cable 2 fault alarm is issued.

[0032] In this embodiment, the PLC acquisition device collects current and temperature signals in analog form, converts them into digital quantities, and then sends them to the monitoring host. Upon receiving the collected information, the monitoring host compiles a control program based on the aforementioned current ratio difference criterion formula and automatically notifies the operator of an alarm signal through audio and text messages.

[0033] It should be noted that, in the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "setting" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances; the drawings in the embodiments are used to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations.

[0034] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A remote monitoring system for the state of a self-limiting temperature heating belt, characterized in that: include: A heating tape power distribution control device, multiple self-limiting temperature heating tapes, a PLC data acquisition device, and a monitoring host; the self-limiting temperature heating tape is installed on the pipeline to be heated, with a current transformer at one end and a temperature sensor at the other end; the PLC data acquisition device connects the current transformer and the temperature sensor to respectively collect the current of the self-limiting temperature heating circuit and the temperature signal of the pipeline surface, and then transmits them to the monitoring host; the self-limiting temperature heating tape is connected to the heating tape power distribution control device, and the monitoring host is connected to the heating tape power distribution control device, and the heating tape power distribution control device is used to control the start or stop of the self-limiting temperature heating tape according to the temperature of the pipeline surface; The monitoring host also determines whether the self-limiting temperature heating tape has a disconnection fault or a heating element failure by comparing the current and length ratio difference of the adjacent self-limiting temperature heating tape, and issues an alarm when a fault occurs; The specific method for comparing the current and length ratio difference of adjacent self-limiting temperature heating belts is: For adjacent self-limiting temperature heating tapes 1 and 2, calculate their current-to-length ratio difference: Kd1 = |I1 / L1 - I2 / L2|. Here, I1 is the current in the SRT1 circuit, and L1 is the length of SRT1. I2 is the current in the SRT2 circuit, and L2 is the length of SRT2. Calculate the average current-to-length ratio: Kd = (I1 / L1 + I2 / L2) / 2. When Kd1 > |I1 / L1 - Kd| or Kd1 > |I2 / L2 - Kd|, a fault alarm signal is issued for the corresponding SRT.

2. The remote monitoring system for the self-limiting temperature heating belt status according to claim 1 is characterized in that: The heating tape power distribution control device includes a PLC controller, multiple contactors and a power supply. The PLC controller is connected to the multiple contactors respectively to control the closing or opening of the contactor contacts; each contactor corresponds to a self-limiting temperature heating tape, and the self-limiting temperature heating tape is connected to the power supply through the contactor.

3. The remote monitoring system for the self-limiting temperature heating belt state according to claim 2 is characterized in that: The monitoring host receives the collected temperature signal. When the temperature is lower than the set first lower limit value, it sends an instruction to the PLC controller to control the contactor contacts to close and start the self-limiting temperature heating tape heating; when the temperature value is higher than the set upper limit value, it sends an instruction to the PLC controller to control the contactor contacts to open and stop the self-limiting temperature heating tape heating.

4. The remote monitoring system for the self-limiting temperature heating belt state according to claim 1 is characterized in that: The remote monitoring system for the status of a self-limiting temperature heating tape according to claim 1 is characterized in that when the temperature received by the monitoring host is lower than a second lower limit value, it indicates that the corresponding self-limiting temperature heating tape has a fault and an alarm signal is issued; wherein the second lower limit value is less than the first lower limit value.

5. The remote monitoring system for the self-limiting temperature heating belt state according to claim 1 is characterized in that: The monitoring host is set with a heating tape loop fault current setting value. When the collected current is greater than the setting value, it is determined that a short circuit fault occurs in the corresponding heating tape.

6. The remote monitoring system for the self-limiting temperature heating belt state according to claim 1 is characterized in that: The PLC acquisition device is connected to the monitoring host via an optical cable. The I / O board inside the PLC acquisition device is connected to the current transformer and temperature sensor, receives the analog signal collected by the sensor, converts it into a digital signal, and then sends it to the monitoring host via the optical cable.

7. The remote monitoring system for the self-limiting temperature heating belt state according to claim 2 is characterized in that: An air circuit breaker is provided between the contactor and the power supply for short circuit or overcurrent protection.

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