Heating control method of nuclear power plant pipeline emergency heating device

Abstract

The invention relates to a heating control method of a nuclear power plant pipeline emergency heating device, which comprises the following steps of: determining a heating device to be controlled to obtain at least one target heating device; the set heating temperature of each target heating device is obtained, and the target heating devices are controlled to heat the pipeline according to the set heating temperatures; and collecting real-time working data of each target heating device to monitor the heating process. After the at least one target heating device is determined, the corresponding set heating temperature is obtained for control, the control requirement for simultaneous heating of the multiple heating devices can be met, and the heating temperature can be adjusted. In addition, the heating process of each target heating device is monitored in real time, potential safety hazards can be found in time, and the safety of pipeline heating is improved.

Description

Technical Field

[0001] The present invention relates to the field of control of electrical equipment in nuclear power plants, and particularly to a heating control method for an emergency heating device for pipelines in a nuclear power plant. Background Art

[0002] In a nuclear power plant, armored electric tracing cables are used to trace heat for pipelines such as boric acid pipelines, sodium solution pipelines, chilled water, instrument pipelines and other special process pipelines to maintain the fluid temperature and prevent crystallization or freezing of boric acid, sodium solution and other fluid media. However, the laying and removal operation processes of the electric tracing cables are relatively cumbersome, and the large number of processes makes it difficult to control the quality of the laying and removal processes of the electric tracing cables, and the construction and installation time is long. Especially, the removal of the electric tracing cables is more difficult, and any carelessness may damage the pipelines, which poses certain potential safety hazards to the safe and stable operation of the electric tracing system. Therefore, a pipeline emergency heating tape is used as an alternative solution, which can be quickly installed on the pipeline to achieve emergency heating of the pipeline. After the pipeline emergency heating tape is installed, an electric control device is required to supply power for heating. Therefore, there is an urgent need to design a heating control method for an emergency heating device for pipelines in a nuclear power plant to control the process of heating the pipeline. Summary of the Invention

[0003] The technical problem to be solved by the present invention is how to control the emergency heating device to heat the pipeline.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a heating control method for an emergency heating device for pipelines in a nuclear power plant, comprising the following steps: determining the heating device to be controlled to obtain at least one target heating device; respectively obtaining the set heating temperature of each target heating device, and controlling the target heating device to heat the pipeline according to the set heating temperature; collecting the real-time working data of each target heating device to monitor the heating process.

[0005] Further, the step of controlling the target heating device to heat the pipeline according to the set heating temperature includes: measuring the actual heating temperature of the target heating device in real time; when the actual heating temperature is lower than the set heating temperature, controlling the target heating device to heat up; when the actual heating temperature is higher than the set heating temperature, controlling the target heating device to cool down.

[0006] Further, the heating control method further includes: determining the set heating-up rate and the set cooling-down rate of each target heating device; when the target heating device heats up, controlling the target heating device according to the power-on time and the power-off time determined by the set heating-up rate; when the target heating device cools down, controlling the target heating device according to the power-on time and the power-off time determined by the set cooling-down rate.

[0007] Further, the step of collecting real-time working data of each target heating device to monitor the heating process includes: if it is determined that the target heating device is abnormal according to the real-time working data, an alarm prompt is given.

[0008] Further, the real-time working data includes the input current of the target heating device; when the target heating device is in an on state with the power supply unit, if the input current is 0, it is determined that there is an abnormal power outage, and a first prompt signal is output.

[0009] Further, the real-time working data includes the input current of the target heating device; when the input current exceeds a preset current threshold, it is determined that the heating is overloaded, and a second prompt signal is output.

[0010] Further, the real-time working data includes the actual heating temperature of the target heating device; when the difference between the actual heating temperature and the set heating temperature exceeds a first temperature threshold, it is determined that the heating temperature is too high, and a third prompt signal is output.

[0011] Further, the real-time working data includes the actual heating temperatures of each target heating device at different temperature measurement points; if the difference between two of the actual heating temperatures exceeds a second temperature threshold, it is determined that the heating is uneven, and a fourth prompt signal is output.

[0012] Further, the step of collecting real-time working data of each target heating device includes: measuring the actual heating temperatures of each target heating device at different temperature measurement points through a temperature sensor; wherein, at least two temperature measurement points are arranged at intervals along the axial direction of the temperature sensor.

[0013] Further, the temperature sensor includes at least two thermocouples, a housing and an insulating medium; a channel is formed inside the housing, the hot ends of the thermocouples are arranged at intervals along the axial direction of the channel, and the insulating medium is filled in the channel; the hot end of each thermocouple forms a temperature measurement point.

[0014] Implementing the present invention has the following beneficial effects: after determining at least one target heating device, the corresponding set heating temperatures are obtained respectively for control, which can meet the control requirements for multiple heating devices to heat simultaneously, and the heating temperature can be adjusted. In addition, the heating process of each target heating device is monitored in real time, potential safety hazards can be discovered in time, and the safety of pipeline heating is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below in conjunction with the drawings and embodiments, in the drawings:

[0016] Figure 1 is the main structural view of the electric control device in some embodiments of the present invention;

[0017] Figure 2 is a structural side view of an electric control device in some embodiments of the present invention;

[0018] Figure 3 is a flowchart of a heating control method for a nuclear power plant pipeline emergency heating device in some embodiments of the present invention;

[0019] Figure 4 is a schematic structural diagram of a temperature sensor in some embodiments of the present invention. Detailed implementation manners

[0020] For a clearer understanding of the technical features, objectives, and effects of the present invention, the detailed implementation manners of the present invention will now be described with reference to the accompanying drawings. In the following description, it should be understood that the terms "first", "second", "third", etc. are only for the convenience of describing the technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", "third", etc. may explicitly or implicitly include one or more of such features. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] In the following description, specific details such as specific system structures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present invention. However, those skilled in the art should clearly understand that the present invention can also be implemented in other embodiments without these specific details. In other cases, the detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present invention.

[0022] The heating control method of the nuclear power plant pipeline emergency heating device of the present invention can be applied to an electric control device, which is used to execute the heating control method to control the emergency heating device. The emergency heating device in this embodiment uses a heating tape, which can wrap the pipeline, generate heat to heat the pipeline when powered on, and stop heating when powered off. In other embodiments, the emergency heating device can also use other types of heating devices.

[0023] Such as Figure 1 and Figure 2As shown, in one embodiment, the electric control device includes a power supply unit, a PLC control unit (programmable logic controller), a fault alarm indicator 1, a touch operation screen 2, a front cabinet door lock 3, a cabinet body 4, a power switch 5, a power indicator 6, a first heating circuit manual switch 7, a second heating circuit manual switch 8, a third heating circuit manual switch 9, a fourth heating circuit manual switch 10, an automatic start switch 11, an emergency stop button 12, a first heating circuit working indicator 13, a second heating circuit working indicator 14, a third heating circuit working indicator 15, a fourth heating circuit working indicator 16, a heating tape storage box 17, a handrail 18, a pulley 19, a power socket 20, a temperature sensor socket 21, and a heating plug 22. The touch operation screen, each indicator, and each switch are communicatively connected to the PLC control unit. The electric control device of this embodiment allows controlling four heating tapes. In other embodiments, the number of heating tapes controlled can be adjusted according to actual needs, such as two, three, five, or more.

[0024] The fault alarm indicator 1 lights up and emits a beeping sound when an abnormality occurs in the target heating device. The touch operation screen 2 serves as the human-machine interface of the electric control device, and the user completes automated control operations on this interface. The front cabinet door lock 3 facilitates the opening of the interior of the cabinet body 4. The power switch 5 is the main power switch of the electric control device. The power indicator 6 lights up after the electric control device is powered on. Each heating circuit manual switch allows the user to manually turn on or off the heating tape of its respective circuit. By setting the automatic start switch 11, an automatic working mode or a manual working mode can be set. The heating tape storage box 17 is used to place the heating tape and provides a certain degree of protection. The handrail 18 is used to push the device to move. Two of the pulleys 19 have a limiting function, which can not only facilitate the short-distance movement of the device and improve mobility but also maintain stability during operation. The power socket 20 is used to connect to an external power source. After receiving power from the power socket 20, the power supply unit provides it to the heating tape through the heating plug 22. Each temperature sensor socket 21 is respectively connected to a temperature sensor and receives the monitoring signal of the temperature sensor. Each heating plug 22 is respectively connected to one heating tape and outputs electrical energy to the heating tape. The PLC control unit is used to execute programs to implement the heating control method of the nuclear power plant pipeline emergency heating device of the present invention.

[0025] A leakage protection switch and a fuse are connected in series between the power supply unit and each heating plug 22 to prevent safety accidents or other unpredictable dangers caused by the leakage of the heating tape.

[0026] As Figure 3 shown, in one embodiment of the heating control method of the nuclear power plant pipeline emergency heating device of the present invention, the following steps are included:

[0027] S1. Determine the heating device to be controlled to obtain at least one target heating device.

[0028] Specifically, in the manual working mode, the user can select the heating tape by turning on the manual switch of the heating circuit. The PLC control unit determines the heating tape to be controlled according to the selection instruction input by the manual switch of the heating circuit, and uses it as the target heating device. In the automatic working mode, the user can select the heating tape to be controlled on the operation interface of the touch operation screen, and the touch operation screen sends the selection instruction to the PLC control unit in the form of an analog signal. The user can choose to control some of the heating tapes or all four heating tapes simultaneously.

[0029] S2. Obtain the set heating temperature of each target heating device respectively, and control the target heating device to heat the pipeline according to the set heating temperature.

[0030] Specifically, the user can set the heating temperature of each target heating device on the touch operation screen respectively. The touch operation screen sends each set heating temperature to the PLC control unit. After receiving the start signal, the PLC control unit energizes the target heating tape and controls the heating tape to heat the pipeline at the set heating temperature. The set heating temperatures of different target heating devices can be the same or different. In other embodiments, if the user does not set the heating temperature, the PLC control unit can use the initial heating temperature as the set heating temperature to control each heating tape.

[0031] In one embodiment, the step of controlling the target heating device to heat the pipeline according to the set heating temperature includes: measuring the actual heating temperature of the target heating device in real time. When the actual heating temperature is lower than the set heating temperature, control the target heating device to heat up. When the actual heating temperature is higher than the set heating temperature, control the target heating device to cool down.

[0032] Specifically, the heating tape wraps the pipeline, and the temperature sensor is inserted into the gap between the heating tape and the pipeline. Without other additional fixing methods, it is convenient and fast, fully contacts with the heating tape, and the temperature measurement is more accurate. Each temperature sensor measures the temperature data of one heating tape in real time, connects to the temperature sensor socket through a cable, and then sends the temperature data to the PLC control unit. In addition, the PLC control unit can also send the actual heating temperature to the touch operation screen for display. When the actual heating temperature is lower than the set heating temperature, control the heating tape to heat up, otherwise control the heating tape to cool down, so that the heating tape is stabilized at the set heating temperature and ensure the heating effect on the pipeline.

[0033] In this embodiment, a solid-state relay is provided between the power supply unit of the electric control device and each heating plug. When the actual heating temperature of a certain heating belt is lower than the set heating temperature, the PLC control unit outputs a 24V low-voltage electrical signal to the solid-state relay. The relay coil is energized and the contact is closed, and the heating belt of this path is energized and starts to heat up. When the actual heating temperature of a certain heating belt is higher than the set heating temperature, the PLC control unit stops outputting a 24V low-voltage electrical signal to the solid-state relay. The relay coil loses power and the contact is disconnected, and the heating belt of this path is powered off and stops, and the heating belt starts to cool down. In this way, temperature control is achieved. In other embodiments, a contactor can also be used to replace the relay.

[0034] Furthermore, the heating control method further includes: determining the set heating-up rate and the set cooling-down rate of each target heating device. When the target heating device is heating up, the target heating device is controlled according to the energization time and the power-off time determined by the set heating-up rate. When the target heating device is cooling down, the target heating device is controlled according to the energization time and the power-off time determined by the set cooling-down rate.

[0035] Specifically, the user sets the heating-up rate and the cooling-down rate of each heating belt to be controlled through the touch operation screen, and then sends them to the PLC control unit through the touch operation screen. If the user does not set the heating-up rate and the cooling-down rate, the PLC control unit uses the initial heating-up rate and the initial cooling-down rate as the set heating-up rate and the set cooling-down rate. For example, the initial heating-up rate and the initial cooling-down rate are 1°C / min. When the actual heating temperature is lower than the set heating temperature, the target heating device is controlled to heat up according to the set heating-up rate. When the actual heating temperature is higher than the set heating temperature, the target heating device is controlled to cool down according to the set cooling-down rate. In this embodiment, the heating and cooling are achieved by intermittently controlling the energization and power-off of the heating belt. The higher the heating-up rate, the longer the energization time; the higher the cooling-down rate, the longer the power-off time. The energization time and the power-off time are determined according to the set heating-up rate and the set cooling-down rate respectively, and then the heating belt is powered on or off intermittently to achieve the corresponding rate. Reasonable use of the set heating-up rate can achieve soft start of the heating belt.

[0036] S3. Monitor the heating process by collecting the real-time working data of each target heating device.

[0037] Specifically, during the heating process, the real-time working data of each target heating device is collected in real time for monitoring. If it is determined that the target heating device is abnormal according to the real-time working data, an alarm prompt is given.

[0038] After determining at least one target heating device, the heating control method of this embodiment respectively obtains the corresponding set heating temperature for control, which can meet the control requirements of multiple heating devices for simultaneous heating and realize adjustable heating temperature. In addition, the heating process of each target heating device is monitored in real time, which can timely detect potential safety hazards and improve the safety of pipeline heating.

[0039] In one embodiment, the real-time working data includes the input current of the target heating device. When the target heating device is in an on state with the power supply unit, if the input current is 0, it is determined that there is an abnormal power failure, and a first prompt signal is output.

[0040] This embodiment uses a Hall current sensor to detect the current input to the heating tape. When it is detected that the contactor or solid-state relay is in a closed state but there is no current flowing into the corresponding heating tape, it is determined that there is an abnormal power failure, and the PLC control unit outputs a first prompt signal. The fault indicator light is turned on when it receives the first prompt signal, prompting the user that a fault has occurred. In addition, the PLC control unit can also output the first prompt signal to the touch operation screen, and the touch operation screen displays this prompt signal on the display interface.

[0041] In another embodiment, when the input current exceeds the preset current threshold, it is determined that there is a heating overload, and a second prompt signal is output. When the current input to a certain heating tape exceeds the preset current threshold, it is determined that there is a heating overload for this heating tape, and the PLC control unit outputs a second prompt signal. The fault indicator light is turned on when it receives the second prompt signal, prompting the user that a fault has occurred. In addition, the PLC control unit can also output the second prompt signal to the touch operation screen, and the touch operation screen displays this prompt signal on the display interface, for example, the red light on the display interface will flash continuously.

[0042] In one embodiment, the real-time working data includes the actual heating temperature of the target heating device. When the difference between the actual heating temperature and the set heating temperature exceeds the first temperature threshold, it is determined that the heating temperature is too high, and a third prompt signal is output.

[0043] This embodiment uses a temperature sensor with multiple thermocouples to measure the heating temperature of the heating tape, and the measurement data of one of the thermocouples can be selected as the actual heating temperature. The first temperature threshold is 10°C, and other temperature values can also be taken in other embodiments. When the actual heating temperature of a certain heating tape is greater than the set heating temperature by more than 10°C, the PLC control unit determines that the heating temperature is too high and outputs a third prompt signal. The fault indicator light is turned on when it receives the third prompt signal, prompting the user that a fault has occurred. In addition, the PLC control unit can also output the third prompt signal to the touch operation screen, and the touch operation screen displays this prompt signal on the display interface.

[0044] In one embodiment, the real-time working data includes the actual heating temperatures of each target heating device at different temperature measurement points. If the difference between two of the actual heating temperatures exceeds the second temperature threshold, it is determined that the heating is uneven, and a fourth prompt signal is output. Specifically, collecting the real-time working data of each target heating device includes: measuring the actual heating temperatures of each target heating device at different temperature measurement points through a temperature sensor; wherein, at least two temperature measurement points are arranged at intervals along the axial direction of the temperature sensor.

[0045] In this embodiment, an armored thermocouple temperature sensor is selected. The temperature sensor includes at least two thermocouples, a housing, and an insulating medium. A channel is formed inside the housing, the hot ends of the thermocouples are arranged at intervals along the axial direction of the channel, and the insulating medium is filled in the channel; the hot end of each thermocouple forms a temperature measurement point.

[0046] As Figure 4 shown, the temperature sensor includes a first thermocouple 23, a second thermocouple 24, and a third thermocouple 25. The housing 26 is a metal tube, a channel is formed inside the housing, the hot ends of the three thermocouples are arranged at intervals along the axial direction of the channel, the cold ends of the thermocouples are connected to cables, and then are connected to the temperature sensor socket through an aviation plug. One hot end is a temperature measurement point, each thermocouple can measure temperature, and one temperature sensor can provide three temperature inputs for one heating belt. The insulating medium 27 includes mineral insulating materials and other related accessories. In other embodiments, the temperature sensor can also be provided with more thermocouples, and the more thermocouples there are, the larger the diameter of the tubular housing is.

[0047] In other embodiments, other types of temperature sensors can also be selected as long as they can measure the temperatures at multiple points on the heating belt.

[0048] For example, the temperature measured by the temperature measurement point closest to the end of the channel is used for actual control of the heating belt, and the temperatures measured by the other two temperature measurement points are used for comparison and reference. If the temperatures measured by the other two points and the temperature measured by the end temperature measurement point exceed the second temperature threshold (usually set at 5°C), the PLC control unit determines that the temperature difference between each point of the heating belt is too large, the heating of the heating belt is uneven, and a fourth prompt signal is output. The fault indicator light is powered on and lit when receiving the fourth prompt signal, prompting the user that a fault has occurred. In addition, the PLC control unit can also output the fourth prompt signal to the touch operation screen, and the touch operation screen displays this prompt signal on the display interface.

[0049] By executing the heating control method of the nuclear power plant pipeline emergency heating device disclosed in the above embodiments, the electric control device can realize various functions such as multi-channel heating start and stop, accurate temperature control, fault identification and alarm, soft start of the heating belt, and temperature rise rate control. In addition, the electric control device also has the function of data recording and storage.

[0050] It can be understood that the above embodiments only represent the preferred embodiments of the present invention, and the description thereof is relatively specific and detailed. However, it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, all equivalent transformations and modifications made to the scope of the claims of the present invention shall fall within the scope covered by the claims of the present invention.

Claims

1. A heating control method for a nuclear power plant pipeline emergency heating device, characterized in that: The following steps are involved: Determining a heating device to be controlled to obtain at least one target heating device; respectively obtaining a set heating temperature of each target heating device, and controlling the target heating device to heat the pipeline according to the set heating temperature; Collect real-time working data of each target heating device to monitor the heating process.

2. The heating control method for the nuclear power plant pipeline emergency heating device according to claim 1, characterized in that: The step of controlling the target heating device to heat the pipeline according to the set heating temperature comprises: measuring the actual heating temperature of the target heating device in real time; When the actual heating temperature is lower than the set heating temperature, controlling the target heating device to heat and increase the temperature; When the actual heating temperature is higher than the set heating temperature, the target heating device is controlled to lower its temperature.

3. The heating control method for the nuclear power plant pipeline emergency heating device according to claim 2, characterized in that: The heating control method further includes: Determine a set heating rate and a set cooling rate for each target heating device; When the target heating device is heated up, controlling the target heating device according to the power-on time and the power-off time determined by the set heating rate; When the target heating device is cooled down, the target heating device is controlled according to the power-on time and the power-off time determined by the set cooling rate.

4. The heating control method for the nuclear power plant pipeline emergency heating device according to claim 1, characterized in that: The step of collecting the real-time working data of each target heating device to monitor the heating process includes: If it is determined according to the real-time working data that the target heating device is abnormal, an alarm is issued.

5. The heating control method for the nuclear power plant pipeline emergency heating device according to claim 4, characterized in that: The real-time working data includes the input current of the target heating device; When the target heating device is connected to the power supply unit, if the input current is 0, it is determined that an abnormal power failure has occurred, and a first prompt signal is output.

6. The heating control method for the nuclear power plant pipeline emergency heating device according to claim 4, characterized in that: The real-time working data includes the input current of the target heating device; When the input current exceeds the preset current threshold, it is determined that the heating is overloaded and a second prompt signal is output.

7. The heating control method for the nuclear power plant pipeline emergency heating device according to claim 4, characterized in that: The real-time working data includes the actual heating temperature of the target heating device; When the difference between the actual heating temperature and the set heating temperature exceeds a first temperature threshold, it is determined that the heating temperature is too high, and a third prompt signal is output.

8. The heating control method for the nuclear power plant pipeline emergency heating device according to claim 4, characterized in that: The real-time working data includes the actual heating temperature of each target heating device at different temperature measurement points; If the difference between two actual heating temperatures exceeds the second temperature threshold, it is determined that the heating is uneven and a fourth prompt signal is output.

9. The heating control method for the nuclear power plant pipeline emergency heating device according to claim 8, characterized in that: The collecting of real-time working data of each target heating device comprises: The actual heating temperature of each target heating device at different temperature measurement points is measured by a temperature sensor; Wherein, the temperature sensor is provided with at least two temperature measuring points at intervals along its axial direction.

10. The heating control method for the nuclear power plant pipeline emergency heating device according to claim 9, characterized in that: The temperature sensor includes at least two thermocouples, a housing and an insulating medium; A channel is formed inside the shell, the hot ends of the thermocouples are arranged at intervals along the axial direction of the channel, and the insulating medium is filled in the channel; the hot end of each thermocouple forms a temperature measuring point.

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