CN218917539U

CN218917539U - Fault monitoring and alarming system of electric tracing system

Info

Publication number: CN218917539U
Application number: CN202223224366.6U
Authority: CN
Inventors: 刘书杰; 王爱成; 陈洪河; 张运生; 王德诚; 郑志远
Original assignee: Dezhou Power Plant of Huaneng International Power Co Ltd
Current assignee: Dezhou Power Plant of Huaneng International Power Co Ltd
Priority date: 2022-12-02
Filing date: 2022-12-02
Publication date: 2023-04-25
Anticipated expiration: 2032-12-02

Abstract

And the fault monitoring and alarming system of the electric tracing system. The existing heat tracing band monitoring system mainly detects the temperature of a transmitter incubator, and mainly adopts the principle that a temperature measuring point is added to the incubator, data are transmitted to a cloud server by using a communication technology to carry out signaling, analysis and alarm, but the defects of single temperature point and delayed alarm exist. The composition of the utility model comprises: and the heat tracing cable (5) is provided with a current transformer (2) behind the power switch (1) of the heat tracing cable, the current transformer is electrically connected with a current transducer (3), and the current transducer is electrically connected with a control detector (4). The utility model is used for monitoring and alarming faults of the electric tracing system.

Description

Fault monitoring and alarming system of electric tracing system

Technical field:

the utility model relates to a fault monitoring and alarming system of an electric tracing system.

The background technology is as follows:

in order to prevent some pipelines and meters from being frozen and damaged in winter, electric tracing bands are additionally arranged in many power plants, one type of the electric tracing bands is a self-limiting temperature tracing band, a temperature control switch is not needed, heating power is automatically adjusted according to temperature, once the middle part of the heat tracing band breaks, a reliable detection means is not provided, the heat tracing band is still heated, but the pipelines at the broken part of the heat tracing band are frozen due to the loss of heat tracing, and normal measurement of equipment is affected; the other is an armoured or constant-temperature heat tracing band heating temperature control switch, but the temperature control switches are generally low in accuracy, temperature measuring points are generally arranged on a pipeline which is close to a heat tracing box by a distance of 1-2 meters and do not represent the temperature of the whole system, once the front end of the heat tracing band breaks, the temperature cannot be reflected in time, and a reliable detection and control system is not used for management, so that operation and maintenance staff cannot grasp the working state of the heat tracing band, and need to carry out inspection on site frequently, the working strength and the danger are increased, and the safe and stable operation of a unit is affected.

The existing heat tracing band monitoring system mainly detects the temperature of a transmitter incubator, and mainly adopts the principle that a temperature measuring point is added to the incubator, data are transmitted to a cloud server by using a communication technology to report, analyze and alarm, but the defects of single temperature point and lag in alarm exist, the temperature point is only set on the advantage of a pipeline, and the state of the whole heat tracing system cannot be monitored in time.

The utility model comprises the following steps:

the utility model aims to solve the problems and provide a fault monitoring and alarming system of an electric tracing system.

The above object is achieved by the following technical scheme:

a fault monitoring and alarming system of an electric tracing system comprises the following components: the heat tracing cable is characterized in that a current transformer is arranged behind a power switch of the heat tracing cable and is electrically connected with a current transducer, and the current transducer is electrically connected with a control detector.

The fault monitoring and alarming system of the electric tracing system is characterized in that the control detector is a DCS controller.

The beneficial effects are that:

1. a set of current transformer is additionally arranged after a heat tracing power supply switch, and then the current transformer is converted into 0-20mA standard current through a current transducer, the standard current is sent into a heat tracing control detector, the heat tracing current is detected in real time, a proper minimum and maximum current threshold value is set according to the actual power of a heat tracing cable, and once the limit is exceeded, an alarm contact signal is sent to a DCS to alarm.

2. The utility model can monitor whether the heat tracing system works normally or not in real time by detecting the heat tracing current.

Description of the drawings:

FIG. 1 is a schematic diagram of a self-limiting temperature heat tracing system;

FIG. 2 is a schematic diagram of a constant temperature heat trace system;

in the figure: 1. a power switch; 2. a current transformer; 3. a current transducer; 4. controlling the detector; 5. a heat tracing cable; 6. a temperature controller output contact; 7. thermal resistance; 8. and (5) a sampling tube.

The specific embodiment is as follows:

example 1:

the power of the heat tracing cable is generally less than about 1000W, the working current is generally about 5A, a 5/1A current transformer can be selected, and then the current transformer is converted into a 0-20mADC standard current signal through a circuit transmitter and is sent to a heat tracing control monitor or directly sent to a DCS system.

A fault monitoring and alarming system of an electric tracing system comprises the following components: and a heat tracing cable 5, wherein a current transformer 2 is arranged behind the power switch 1 of the heat tracing cable, the current transformer is electrically connected with a current transducer 3, and the current transducer is electrically connected with a control detector 4.

Referring to fig. 1, the self-temperature-limiting heat tracing band is generally laid directly along the instrumentation tube, and the system operating state can be detected directly by detecting the heat tracing current without providing a temperature detection signal. Assuming that the power of the heat tracing band is 45W/m (10 ℃), the power of the heat tracing band is 20m, the power is 900W, and the working current is about 4A; when the temperature of the pipeline is 60 ℃, the electric tracing power is 35W/m, the tracing band is 20m, the power is 700W, and the working current is about 3A; when the temperature of the pipeline is 0 ℃, the electric tracing power is 47W/m, the tracing band is 20m, the power is 700W, and the working current is about 4.3A;

assuming that the temperature of the pipeline is 10 ℃, if the middle of the heat tracing cable is broken, the power is reduced to 450W, and the working current is about 2A, so that the upper limit threshold of the heat tracing current can be set to be 4.3-4.5A, when the temperature of the pipeline is close to 0 ℃, and the working current exceeds the normal 4A, the controller or DCS logic judges that the heat tracing current is large to give an alarm, and the continuous low temperature of the pipeline is indicated, and the heat tracing system does not work or is in heat preservation absence; the lower limit threshold is set to be 1-2A, and once the intermediate fracture of the heat tracing cable is reduced, the heat tracing current is lost due to tripping of a switch caused by cable short circuit or other reasons, and the current is sent to a controller or a DCS to carry out heat tracing current small alarm.

Example 2:

referring to fig. 2, the constant temperature heat tracing belt is generally laid along an instrument pipeline, a temperature measuring point is arranged on a pipeline which is close to the heat tracing box by a distance of 1-2 meters and enters a temperature controller, the set temperature is adjustable, and the temperature at the tail end of the instrument pipe cannot be detected. By detecting the heat tracing current, whether the heat tracing system works normally or not can be monitored in real time.

Assuming that the total power of the heat tracing band is 1000W, the working current is about 4A, the temperature in the pipeline is measured through the thermal resistor in the pipeline, when the temperature of the pipeline is lower than the set temperature, a temperature signal is transmitted to the control detector, the control detector controls the output joint of the temperature controller to be closed, the current measured by the current transformer is transmitted to the control detector after a period of time delay through the current transmitter, when the measured heat tracing current is smaller than 2-3A, the heat tracing system is not heated after the output joint of the temperature controller is closed, the fault of the heat tracing system can be judged, and the alarm joint is output to the DCS.

The working state of the heat tracing system can be detected in real time by detecting the working current of the heat tracing system, once the faults such as power failure, breakage of a heat tracing cable and the like occur, the heat tracing current can be timely reflected, and is converted into a standard current signal of 0-20mADC through a circuit transmitter and then sent to a heat tracing control monitor or directly sent to a DCS (distributed control system), so that an abnormal alarm is sent out, operators are timely reminded to pay attention, the defects are timely processed, unsafe events caused by abnormal measuring points due to the heat tracing faults are reduced, and safe operation of a unit is ensured.

Claims

1. A fault monitoring and alarming system of an electric tracing system comprises the following components: heat tracing cable, characterized by: the power switch of the heat tracing cable is provided with a current transformer, the current transformer is electrically connected with a current transducer, and the current transducer is electrically connected with a control detector.

2. The electrical tracing system fault monitoring alarm system of claim 1, wherein: the control detector is a DCS controller.