Condensate water prevention device of grounding box in tunnel and grounding box

Abstract

The invention relates to the technical field of grounding boxes, and discloses a condensate water prevention device of a grounding box in a tunnel and the grounding box. The power taking unit is configured to obtain induced voltage of a cable line in the tunnel and supply power to the heater under the condition that the induced voltage is sufficient; the storage battery is configured to supply power to the heater under the condition that the induced voltage is insufficient; the control unit is configured to control at least one of the power taking unit and the storage battery to work under the condition that the temperature in the grounding box is lower than a preset temperature, and control the power taking unit to charge the storage battery; the control unit is configured to determine the standard heating power of the heater and adjust the standard heating power to obtain the target heating power, so that the heater works at the target heating power. According to the application, electricity is taken through the induced voltage of the cable line to supply power to the heater, so that the heating power consumption is reduced, and the long-time endurance of the heater is realized.

Description

Technical Field

[0001] The present application relates to the technical field of grounding boxes, and in particular to an anti-condensation water device for a grounding box in a tunnel and a grounding box. Background Art

[0002] As the reliability requirements for power transmission and supply become higher and higher, the proportion of high-voltage cables in urban power supply lines continues to increase, and the advantages of cable transmission in tunnels are becoming more and more obvious. Cable tunnels are generally located at a depth of tens of meters underground, with a large temperature difference from the outside. In hot seasons or rainy weather, condensation and water droplets are prone to appear in the grounding box in the tunnel, which can easily cause risks such as rust on the bolted connection parts and aging of insulation due to condensation. This greatly affects the safe and stable operation of the cable line test and causes great safety hazards.

[0003] In the related art, the commonly used cabinet dehumidification methods mainly include forced ventilation, desiccant and electric heating. The forced ventilation method is to reduce the humidity in the cabinet by forming convection with the dry air outside, but it is not suitable for the situation where the humidity in the cable tunnel is also high. The desiccant method is to hang a desiccant in the cabinet and use the desiccant to absorb moisture to achieve the purpose of dehumidification, but the desiccant needs to be replaced manually regularly, and the maintenance cost is high. In addition, the grounding box in the tunnel is deep underground, so the difficulty of ventilation and replacement of desiccant is very great. The electric heating method is to install a heater in the box body, and heat the local temperature in the cabinet to increase, thereby reducing the relative humidity in the box. However, since the heater is installed in the grounding box in the tunnel, it is not only difficult to replace the heater battery, but also the power consumption of the heater is large, resulting in the problem that the heater is difficult to last for a long time. Summary of the invention

[0004] The present application provides an anti-condensation water device and a grounding box for a grounding box in a tunnel, which solves the technical problems that the current heaters used to prevent condensation water consume a lot of power and it is inconvenient to replace the battery in the tunnel, resulting in difficulty in long-term battery life and difficulty in being suitable for grounding boxes in tunnels. The present application draws power through the induced voltage of the cable line to power the heater, and adaptively adjusts the heating power of the heater, thereby reducing the heating power consumption and achieving long-term battery life of the heater.

[0005] In order to achieve the above objectives, the main technical solutions adopted in this application include: In a first aspect, an embodiment of the present application provides an anti-condensation water device for a grounding box in a tunnel, the anti-condensation water device comprising: A heater, the heater is arranged on the inner side of the box body side plate of the grounding box, and the heater is used to heat the surrounding space of the grounding copper busbar in the grounding box to evaporate the condensed water in the grounding box; A power taking unit, which is arranged on the outside of the side plate of the box body and is configured to obtain the induced voltage of the cable line in the tunnel and supply power to the heater when the induced voltage is sufficient; a battery configured to supply power to the heater when the induced voltage is insufficient; A control unit, the control unit being configured to control at least one of the power taking unit and the battery to operate when the temperature inside the grounding box is lower than a preset temperature, and to control the power taking unit to charge the battery when the temperature inside the grounding box is not lower than a preset temperature; The control unit is configured to determine the standard heating power of the heater based on the temperature inside the box and the historical load current of the cable line, and adjust the standard heating power according to the real-time load current of the cable line to obtain the target heating power, so that the heater operates at the target heating power.

[0006] The anti-condensation water device proposed in the embodiment of the present application is provided with a heater, a power supply unit, a battery and a control unit in a grounding box in a tunnel, and the power supply unit uses the induced voltage of the cable line as the main power supply for the heater, and uses the battery as the backup power supply for the heater, and the control unit adaptively adjusts the heating power of the heater according to the temperature in the box and the load current of the cable line, so as to dynamically control the heater to keep the temperature in the box at the desired temperature under the heating power suitable for the temperature in the box. Therefore, the embodiment of the present application can utilize the coordinated work of the power supply unit and the battery to ensure that the heater meets the demand for evaporating condensed water, and also adaptively adjust the heating power of the heater to avoid the waste of power supply energy caused by the heater overheating the temperature in the box, greatly reducing unnecessary heating energy consumption, and ensuring that the heater can last for a long time under the energy provided by the induced voltage of the cable line, thereby effectively avoiding grounding box failures caused by condensed water.

[0007] Optionally, in some embodiments of the present application, the control unit is further configured to: When the real-time load current of the cable line is greater than or equal to a first threshold, determining that the induced voltage is sufficient; In a case where the real-time load current of the cable line is less than the first threshold, it is determined that the induced voltage is insufficient.

[0008] The embodiment of the present application realizes real-time monitoring of the induced voltage according to the size of the real-time load current of the cable line, so as to determine whether the induced voltage is sufficient, and then enables the control unit to obtain the energy supply capacity of the cable line in time, so as to realize precise dynamic control of the coordinated work of the power taking unit and the battery.

[0009] Optionally, in some embodiments of the present application, the control unit is further configured to: When the historical load current of the cable line is greater than or equal to the first threshold, the surface temperature of the grounding copper bar is determined according to the historical load current of the cable line, and a thermal field simulation is performed according to the current temperature inside the grounding box, the surface temperature of the grounding copper bar and different heating powers, so as to determine the standard heating power according to the simulation results; When the historical load current of the cable line is less than the first threshold, thermal field simulation is performed according to the current temperature inside the grounding box and different heating powers, so as to determine the standard heating power according to the simulation result; The standard heating power is used to increase the temperature in the box and maintain it at a desired temperature.

[0010] The embodiment of the present application conducts a comprehensive analysis of the temperature inside the box, the surface temperature of the grounding copper busbar, and the load current of the cable line to determine the standard heating power using the thermal field simulation results under different heating powers. The embodiment of the present application introduces the surface temperature of the grounding copper busbar as a factor in the thermal field simulation, and makes full use of the thermal effect generated by the grounding copper busbar's own flow to assist in evaporating condensed water, thereby making the thermal field simulation effect more accurate, and ensuring that the standard heating power determined according to the simulation results can achieve a more accurate and economical energy supply strategy, reduce the unnecessary consumption and waste of the induction power and battery power by the heater, and provide an accurate data basis for subsequent adaptive adjustment to obtain the target heating power, which is conducive to improving the accuracy of the adaptive adjustment.

[0011] Optionally, in some embodiments of the present application, when the historical load current of the cable line is greater than or equal to the first threshold, the control unit is further configured to: Determine a change trend of the real-time load current according to the real-time load current and the historical load current, and obtain a load current fluctuation amount; In the case where the load current fluctuation amount is greater than or equal to a second threshold value, if the real-time load current shows an upward trend, a first adjustment coefficient is determined according to the difference between the load current fluctuation amount and the second threshold value, and the standard heating power is reduced according to the first adjustment coefficient to obtain the target heating power; if the real-time load current shows a downward trend, a second adjustment coefficient is determined according to the difference between the load current fluctuation amount and the second threshold value, and the standard heating power is increased according to the second adjustment coefficient to obtain the target heating power; And when the load current fluctuation amount is smaller than the second threshold value, the standard heating power is used as the target heating power.

[0012] The embodiment of the present application sets the first threshold and the second threshold for adaptive adjustment based on the standard heating power, and can accurately control the heating power of the heater according to the different thermal effects generated by the flow of current through the grounding copper busbar under different load current conditions. The target heating power obtained through the adaptive adjustment can not only more accurately meet the thermal demand for evaporation of condensed water under different load current conditions, but also save electricity consumption, so that the grounding box can be kept stable and dry while maximizing electricity conservation and reducing unnecessary energy waste, so as to avoid the risk of excessive energy consumption of the power taking unit and the battery, which is beneficial to improving the long-term endurance of the heater.

[0013] Optionally, in some embodiments of the present application, the power taking unit includes: A power taking coil, wherein the power taking coil is configured to generate the induced voltage according to the operating magnetic field of the cable line, wherein the coil plane of the power taking coil is perpendicular to the cable line, and the cable line passes through the center point of the coil plane; A rectifier and voltage regulator module, wherein an input end of the rectifier and voltage regulator module is connected to the power taking coil, and the rectifier and voltage regulator module is configured to perform voltage stabilization processing on the induced voltage and output a first voltage signal; A DC / DC conversion module is configured to perform voltage conversion on the first voltage signal and output a second voltage signal, so as to supply power to the heater according to the second voltage signal.

[0014] The embodiment of the present application obtains the induced voltage of the cable line through the power taking coil, and performs voltage stabilization and voltage conversion on the induced voltage through the rectifier voltage stabilization module and the DC / DC conversion module, which can effectively convert the induced voltage generated by the cable running magnetic field into a power source that can directly drive the heater, thereby providing a continuous and relatively independent power supply for the heater. Compared with the traditional method of using batteries to power the heater, the use of power taking units can directly obtain power from the running magnetic field of the tunnel cable, without the need to frequently enter the tunnel to open the grounding box for battery replacement, which is conducive to improving the endurance of the heater, reducing both the manpower maintenance cost and the power utilization rate, and the circuit structure is simple and low cost, thus greatly reducing the construction difficulty.

[0015] Optionally, in some embodiments of the present application, the control unit includes: a first controllable switch connected between the DC / DC conversion module and the heater; A control chip, wherein a first output end of the control chip is connected to a control end of the first controllable switch, and the control chip is configured to control the first controllable switch to close when the temperature inside the grounding box is lower than a preset temperature.

[0016] Optionally, in some embodiments of the present application, the control unit further includes: a second controllable switch connected between the battery and the heater; The first input end of the control chip is connected to the output end of the DC / DC conversion module, and the second output end of the control chip is connected to the control end of the second controllable switch. The control chip is also configured to control the second controllable switch to close when the second voltage signal output by the DC / DC conversion module is lower than the first preset voltage and the temperature inside the grounding box is lower than the preset temperature, so as to power the heater through the battery.

[0017] The embodiment of the present application provides a battery to ensure that the heater can still be effectively powered when the induced voltage of the cable line is insufficient, thereby ensuring the continuous operation of the heater under special working conditions. Through dynamic switching between the power supply unit and the battery, the reliability of the anti-condensation water device is improved while the reasonable distribution and flexible use of electric energy are achieved, thereby ensuring the stability of the anti-condensation water performance to the greatest extent.

[0018] Optionally, in some embodiments of the present application, the control unit further includes: The second input end of the control chip is connected to the output end of the rectifier and voltage regulator module, and the third output end of the control chip is connected to the control end of the rectifier and voltage regulator module. The control chip is also configured to compare the first voltage signal output by the rectifier and voltage regulator module with the second preset voltage, and generate a control signal according to the comparison result and send it to the control end of the rectifier and voltage regulator module.

[0019] The embodiment of the present application compares the first voltage signal corresponding to the induced voltage with the second preset voltage through the control chip, and controls the rectification and voltage regulation module to adjust according to the comparison result to achieve voltage regulation processing of the first voltage signal, thereby improving the power supply quality of the power supply unit.

[0020] In a second aspect, an embodiment of the present application provides a grounding box, the grounding box comprising: Grounding copper busbar; Box; And the anti-condensation water device according to the above embodiment, wherein the anti-condensation water device is arranged inside the grounding box.

[0021] The grounding box proposed in the embodiment of the present application maintains the temperature inside the box at the desired temperature and has a long-term endurance through the anti-condensation water device arranged inside the grounding box. Therefore, while ensuring that the demand for evaporation of condensed water is met, the heating power of the anti-condensation water device can be adaptively adjusted to avoid the anti-condensation water device from over-heating the temperature inside the box and causing a waste of power supply energy, thereby greatly reducing unnecessary heating energy consumption, ensuring that the anti-condensation water device can have a long-term endurance, and thus effectively avoiding grounding box failures caused by condensed water.

[0022] Optionally, the box body includes a box cover and a box bottom, and the box cover and the box bottom are connected by hinges and bolts, and the grounding copper bar is fixed to the box bottom by a metal fixing piece; Wherein, a one-way breathing valve is arranged on the box cover, and the one-way breathing valve is used to discharge water vapor converted from condensed water.

[0023] The embodiment of the present application provides sufficient operating space for operations inside the grounding box through the connection structure between the box cover and the box bottom, which is conducive to the maintenance work and improves work efficiency. In addition, the embodiment of the present application achieves the function of limiting air convection while maintaining the air pressure balance inside and outside the grounding box through the one-way breathing valve set on the box cover, thereby effectively improving the anti-condensation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 A schematic diagram of the structure of an anti-condensation water device for a grounding box in a tunnel proposed in one embodiment of the present application; Figure 2 A schematic diagram of thermal field simulation proposed in one embodiment of the present application; Figure 3 A schematic diagram of the power supply principle of a power taking unit and a battery unit proposed in one embodiment of the present application; Figure 4 A schematic cross-sectional structure diagram of a grounding box proposed in one embodiment of the present application; Figure 5 A schematic diagram of the box structure of a grounding box proposed in one embodiment of the present application; Figure 6 A schematic structural diagram of an anti-condensation water device for a grounding box in a tunnel proposed in another embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0027] With the increasing requirements for the reliability of power transmission and supply, the proportion of high-voltage cables in urban power supply lines continues to increase, and the advantages of cable transmission in tunnels are becoming more and more obvious. The grounding box in the tunnel is an important equipment used in the cable transmission system in the tunnel. It can effectively guide the current of the cable to the ground, thereby providing grounding protection for the cable, preventing electrical fires, electric shocks and other accidents caused by current leakage, so as to ensure the safe operation of the power system. Cable tunnels are generally located at a depth of tens of meters underground, with a large temperature difference from the outside world. In hot seasons or rainy weather, condensation water and water droplets are prone to appear in the grounding box in the tunnel, which is prone to rust of bolted connection parts and insulation aging due to condensation water. This greatly affects the safe and stable operation of the cable line test and causes great safety hazards.

[0028] In some application scenarios, the relevant technologies generally adopt common cabinet dehumidification methods such as forced ventilation, desiccant, semiconductor condensation dehumidification and electric heating. The forced ventilation method is to reduce the humidity in the cabinet by forming convection with the dry air outside, but it is not suitable for the situation where the humidity in the cable tunnel is also high. The desiccant method is to achieve the purpose of dehumidification by hanging desiccant in the cabinet and using the desiccant to absorb moisture, but the desiccant needs to be replaced manually regularly, and the maintenance cost is high. In addition, the grounding box in the tunnel is deep underground, so the difficulty of ventilation and replacement of desiccant is very great. The semiconductor condensation dehumidification method is a dehumidification method that uses a semiconductor condensation device to quickly condense the water molecules contained in the air in the cabinet space into liquid water and discharge it from the cabinet through a guide pipe. Its advantage is rapid condensation, but the effect is not obvious in an environment with low temperature and high humidity, and the construction of a drainage device in the tunnel is difficult and costly.

[0029] In another application scenario, an electric heating method is used to dehumidify the grounding box. The electric heating method is to install a heater in the box to increase the local temperature in the box by heating, thereby reducing the relative humidity in the box. However, the grounding boxes in the tunnel are widely distributed along the cable lines, and it is difficult and costly to lay additional power supply lines in the tunnel to provide electricity for the heating equipment. In addition, since the heater is installed in the grounding box in the tunnel, not only is it difficult to replace the heater battery, but the humidity in the tunnel is also high, and continuous heating is usually required to keep the air in the grounding box dry. Therefore, the power consumption of the heater is large, and solar power generation and other methods are not suitable for the tunnel environment. Therefore, relying solely on battery power cannot meet the requirements of long-term stable operation of the heating system, resulting in the problem of the heater having difficulty in long-term battery life.

[0030] According to an embodiment of the present application, a condensation prevention device 10 for a grounding box in a tunnel is provided, which can be used for a grounding box in a tunnel, and can also be used for power equipment boxes such as a distribution box and a control box, such as Figure 1 As shown, the anti-condensation water device 10 includes a heater 11 , a power extraction unit 12 , a battery 13 and a control unit 14 .

[0031] Among them, the heater 11 is arranged on the inner side of the box side panel of the grounding box, and the heater 11 is used to heat the space around the grounding copper bus in the grounding box to evaporate the condensed water in the grounding box; the power supply unit 12 is arranged on the outer side of the box side panel, and the power supply unit 12 is configured to obtain the induced voltage of the cable line 20 in the tunnel, and supply power to the heater 11 when the induced voltage is sufficient; the battery 13 is configured to supply power to the heater 11 when the induced voltage is insufficient; the control unit 14 is configured to control at least one of the power supply unit 12 and the battery 13 to work when the temperature inside the grounding box is lower than the preset temperature, and to control the power supply unit 12 to charge the battery 13 when the temperature inside the grounding box is not lower than the preset temperature.

[0032] Specifically, the heater 11 is installed on the inner side of the side plate of the grounding box to heat the space around the grounding copper bar to evaporate condensed water, and the power extraction unit 12 is installed on the outer side of the box to obtain sufficient induced voltage from the cable line outside the grounding box to power the heater 11 and serve as the main power source for the heater 11. The battery 13 can be installed inside the grounding box and serve as a backup power source for the heater 11.

[0033] When the temperature inside the grounding box is lower than the preset temperature, the air humidity in the tunnel is high and condensation water is easily generated. Therefore, at least one of the power extraction unit 12 and the battery 13 is controlled to work, wherein the power extraction unit 12 is preferentially used to power the heater 11, and the battery 13 is used to power the heater when the induced voltage is insufficient, so as to continuously and stably evaporate the condensation water and maintain the dry state inside the box. When the temperature inside the grounding box is not lower than the preset temperature, the higher temperature will reduce the generation of condensation water, so there is no need to heat the box additionally. At this time, the induced voltage obtained by the power extraction unit 12 is used to charge the battery 13, so as to make full use of the induced voltage generated by the operating magnetic field of the cable and improve the efficiency of electric energy utilization.

[0034] Furthermore, the control unit 14 is configured to determine the target heating power of the heater 11 based on the temperature inside the box and the historical load current of the cable line 20, and adaptively adjust the standard heating power according to the real-time load current of the cable line 20 to obtain the target heating power, so that the heater 11 operates at the target heating power.

[0035] Since the grounding copper busbar has a certain surface temperature due to its own current flow, and the greater the real-time load current of the cable line 20, the greater the current flowing through the grounding copper busbar, which in turn causes the surface temperature to increase with the increase of the load current. Considering that the surface temperature of the grounding copper busbar will produce a certain thermal effect on the surrounding space, it can assist in the evaporation of condensed water to a certain extent. In addition, the energy of the power supply unit 12 and the battery 13 comes from the induced voltage of the cable line 20, and its energy supply is limited. Therefore, if the surface temperature of the grounding copper busbar is large enough, the power of the heater 11 can be appropriately reduced, thereby saving the energy supply of the power supply unit 12 and the battery 13, and further improving the long-term endurance of the heater 11.

[0036] Therefore, the embodiment of the present application determines the corresponding standard heating power based on the temperature inside the box and the historical load current of the cable line 20, and adaptively adjusts the standard heating power according to the real-time load current of the cable line 20, thereby determining the heating power that can both achieve anti-condensation water energy supply and save electricity.

[0037] The anti-condensation water device 10 proposed in the embodiment of the present application is provided with a heater 11, a power supply unit 12, a battery 13 and a control unit 14 in a grounding box in a tunnel, and the power supply unit 12 uses the induced voltage of the cable line 20 as the main power supply of the heater 11, and uses the battery 13 as the backup power supply of the heater 11, and the control unit 14 adaptively adjusts the heating power of the heater 11 according to the temperature in the box and the load current of the cable line 20, so as to dynamically control the heater 11 to keep the temperature in the box at the desired temperature under the heating power suitable for the temperature in the box. Therefore, the embodiment of the present application can utilize the coordinated work of the power supply unit 12 and the battery 13 to ensure that the heater 11 meets the demand for evaporating condensed water, and also adaptively adjusts the heating power of the heater 11 to avoid the waste of power supply energy caused by the excessive heating of the temperature in the box by the heater 11, greatly reducing unnecessary heating energy consumption, so as to ensure that the heater 11 can last for a long time under the energy provided by the induced voltage of the cable line 20, thereby effectively avoiding the grounding box failure caused by condensed water.

[0038] In some embodiments of the present application, the control unit 14 is further configured to: When the real-time load current of the cable line 20 is greater than or equal to the first threshold, determining that the induced voltage is sufficient; In the case where the real-time load current of the cable line 20 is less than the first threshold, it is determined that the induced voltage is insufficient.

[0039] It should be noted that in the embodiment of the present application, the first threshold is determined according to the minimum heating power of the heater 11, that is, only when the real-time load current of the cable line 20 reaches at least the first threshold, its corresponding induced voltage can support the operation of the heater 11. When the load current passes through the cable line 20, a magnetic field will be generated in the surrounding area, so that the power extraction unit 12 generates an induced voltage based on the magnetic field. The greater the real-time load current, the greater the surrounding magnetic field strength, and the induced voltage generated in the power extraction unit 12 will also increase accordingly, so the real-time load current of the cable line 20 is positively correlated with the induced voltage.

[0040] Therefore, in special circumstances such as power outage or low voltage in the cable line 20, the real-time load current is very small, causing the induced voltage to drop to a level that is insufficient to support the operation of the heater 11. At this time, if the temperature inside the grounding box is lower than the preset temperature, the battery 13 is required to power the heater 11.

[0041] The embodiment of the present application realizes real-time monitoring of the induced voltage according to the load current of the cable line 20, so as to determine whether the induced voltage is sufficient, and then enables the control unit 14 to obtain the energy supply capacity of the cable line 20 in time, so as to realize precise dynamic control of the coordinated operation of the power supply unit 12 and the battery 13.

[0042] In some embodiments of the present application, the control unit 14 is further configured to: when the historical load current of the cable line is greater than or equal to a first threshold value, determine the surface temperature of the grounding copper busbar according to the historical load current of the cable line, and perform thermal field simulation according to the current box temperature of the grounding box, the surface temperature of the grounding copper busbar and different heating powers to determine the standard heating power according to the simulation results; when the historical load current of the cable line is less than the first threshold value, perform thermal field simulation according to the current box temperature of the grounding box and different heating powers to determine the standard heating power according to the simulation results.

[0043] The standard heating power is used to increase the temperature inside the box and maintain it at the desired temperature.

[0044] Since the current flowing through the grounding copper bar is very small when the load current is less than the first threshold, the thermal effect of the grounding copper bar can be ignored. Therefore, in the embodiment of the present application, the influence of the surface temperature of the grounding copper bar on the temperature inside the box needs to be considered only when the historical load current is greater than or equal to the first threshold.

[0045] It should be noted that, during the operation of the heater 11, the control unit 14 adjusts the target heating power according to a preset cycle, wherein the historical load current in the embodiment of the present application may be the load current of the cable line 20 at the end of the previous cycle, or may be the average load current of the cable line 20 in the previous cycle. In addition, the embodiment of the present application determines the historical grounding current corresponding to the grounding copper busbar according to the historical load current, and determines the surface temperature of the grounding copper busbar according to the Joule heat distribution generated by the historical grounding current.

[0046] In some embodiments of the present application, the heat transfer analysis module in COMSOL software is used to establish a three-dimensional model of the grounding box and the heating system. For example, the size of the grounding box is set to 30cm×20cm×50cm, the box is an air fluid domain, two heaters 11 are configured, and the heaters 11 are installed on the side of the grounding box according to the spatial arrangement of the original equipment in the grounding box, and the spacing distance between the grounding copper bar and the side of the grounding box where the heaters 11 are installed is set, and the surface temperature of the grounding copper bar is set to the surface temperature of the grounding copper bar corresponding to the historical load current. In addition, it is also necessary to set the geometric structure, thermal conductivity, density, specific heat capacity and other properties of the grounding copper bar in the above three-dimensional model, set the current temperature in the box to 25°C, adjust the heater 11 to work at different powers, and simulate the thermal field distribution under the corresponding power.

[0047] Figure 2 The thermal field simulation results for the above example are shown in Figure 2As shown, the surface temperature of heater 11 reaches 126°C, which is also the highest point in the grounding box. The temperature around the heater is high. Since the temperature inside the external box is low and the metal shell of the grounding box dissipates heat quickly, the temperature drops rapidly as the distance from the heater increases.

[0048] The embodiment of the present application calculates the average temperature between the heater 11 and the grounding copper busbar based on the thermal field simulation results. For example, the average temperature calculation results corresponding to the simulation results shown in the above example are shown in Table 1.

[0049] Table 1 As can be seen from Table 1, when the grounding box heater 11 is running and reaches stability, the box temperature can be increased and maintained at a certain level. In order to ensure sufficient heating efficiency, the box temperature should not be too low, and in order to avoid overheating in the box and damage to components, the temperature should not be too high. The expected temperature is set to 35°C to 40°C. Therefore, it can be obtained that when the current box temperature is 25°C, the standard heating power corresponding to the historical load current is 30W.

[0050] The embodiment of the present application conducts a comprehensive analysis of the temperature inside the box, the surface temperature of the grounding copper busbar, and the load current of the cable line to determine the standard heating power using the thermal field simulation results under different heating powers. The embodiment of the present application introduces the surface temperature of the grounding copper busbar as a factor in the thermal field simulation, and makes full use of the thermal effect generated by the grounding copper busbar's own flow to assist in evaporating condensed water, thereby making the thermal field simulation effect more accurate, and ensuring that the standard heating power determined according to the simulation results can achieve a more accurate and economical energy supply strategy, reduce the unnecessary consumption and waste of the induction power and battery power by the heater 11, and provide an accurate data basis for subsequent adaptive adjustment to obtain the target heating power, which is conducive to improving the accuracy of the adaptive adjustment.

[0051] In some embodiments of the present application, the control unit 14 is further configured to perform the following adaptive adjustment process, including: Step S1, determining the change trend of the real-time load current according to the real-time load current and the historical load current, and obtaining the load current fluctuation amount, wherein if the real-time load current is greater than or equal to the historical load current, it is determined that the real-time load current is on an upward trend; if the real-time load current is less than the historical load current, it is determined that the real-time load current is on a downward trend, and the load current fluctuation amount is the absolute value of the difference between the real-time load current and the historical load current.

[0052] Step S2, when the load current fluctuation is greater than or equal to the second threshold value, if the real-time load current shows an upward trend, the first adjustment coefficient is determined according to the difference between the load current fluctuation and the second threshold value, and the standard heating power is reduced according to the first adjustment coefficient to obtain the target heating power; if the real-time load current shows a downward trend, the second adjustment coefficient is determined according to the difference between the load current fluctuation and the second threshold value, and the standard heating power is increased according to the second adjustment coefficient to obtain the target heating power; and when the load current fluctuation is less than the second threshold value, the standard heating power is used as the target heating power.

[0053] Specifically, since the load current of the cable line 20 will fluctuate with the change of the load, the current flowing through the grounding copper busbar will also fluctuate. When the current flows through the grounding copper busbar, it will generate heat due to its resistance, and there is a Joule heating effect. Therefore, the change of the load current will make the surface temperature of the grounding copper busbar fluctuate, and the fluctuation amplitude will be large in the case of a sudden load change, thereby affecting the change of the temperature in the box. In response to the above-mentioned fluctuations, the embodiment of the present application further accurately adjusts the standard heating power according to the load current fluctuation amount and the second threshold value, so as to better meet the anti-condensation water requirements while saving the energy consumption of the power extraction unit 12 and the battery 13.

[0054] Among them, when the load current fluctuation is greater than or equal to the second threshold value, if the load current of the cable line 20 shows an upward trend and the increase is large, the surface temperature of the grounding copper busbar will increase significantly at this time. If the heater 11 continues to work at the standard heating power determined above, there will be overheating, resulting in a waste of electric energy of the power taking unit 12. Therefore, the standard heating power is appropriately reduced according to the first adjustment coefficient to fully utilize the thermal effect of the grounding copper busbar to assist the evaporation of condensed water. On the contrary, if the load current of the cable line 20 shows a downward trend and the decrease is large, the surface temperature of the grounding copper busbar will decrease significantly at this time. If the heater 11 continues to work at the standard heating power determined above, there will be insufficient heating, affecting the anti-condensation effect, and it is necessary to appropriately increase the standard heating power to ensure the evaporation of condensed water. Therefore, the standard heating power is appropriately increased according to the second adjustment coefficient.

[0055] When the load current fluctuation is less than the second threshold, it indicates that the real-time load current does not change much, and thus the surface temperature of the grounding copper bar does not change much, so the heater 11 can continue to work at the above-determined standard heating power.

[0056] It should be noted that, the greater the difference between the load current fluctuation and the second threshold, the greater the first adjustment coefficient and the second adjustment coefficient, that is, the load current fluctuation is positively correlated with the first adjustment coefficient and the second adjustment coefficient, respectively.

[0057] The embodiment of the present application sets the first threshold and the second threshold to adaptively adjust on the basis of the standard heating power, and can accurately control the heating power of the heater according to the different thermal effects generated by the flow of current through the grounding copper busbar under different load current conditions. The target heating power obtained through the adaptive adjustment can not only more accurately meet the thermal demand for evaporation of condensed water under different load current conditions, but also save electricity consumption, so that the grounding box can be kept stable and dry while maximizing electricity conservation and reducing unnecessary energy waste, so as to avoid the risk of excessive energy consumption of the power taking unit and the battery, which is beneficial to improving the long-term endurance of the heater.

[0058] Furthermore, in some embodiments of the present application, the control unit 14 is further configured to: Determine a pre-trained load current prediction model, and input the historical load current and the real-time load current into the load current prediction model to obtain a predicted load current in a future time period according to the load current prediction model, and determine a predicted average load current in the future time period; The predicted average load current and the real-time load current are compared, and one of the first adjustment coefficient and the second adjustment coefficient is optimized according to the comparison result.

[0059] Specifically, when the real-time load current shows an upward trend, the surface temperature of the grounding copper bar shows an upward trend accordingly. If the predicted average load current is less than the real-time load current, it means that the surface temperature of the grounding copper bar may drop in the future. Therefore, although the heating power of the heater 11 needs to be reduced at this time, the heating power of the heater 11 may need to return to a higher level in the future. In some embodiments of the present application, the first adjustment coefficient is multiplied by the first preset parameter, wherein the first preset parameter is a positive number less than 1, so as to reduce the first adjustment coefficient, so that the degree of reduction of the standard heating power can be appropriately reduced to cope with the future load current change trend in advance. If the predicted average load current is greater than or equal to the real-time load current, it means that the surface temperature of the grounding copper bar may continue to rise in the future, so the first adjustment coefficient is kept unchanged.

[0060] In the case where the real-time load current is on a downward trend, correspondingly, the surface temperature of the grounding copper bar is on a downward trend at this time. If the predicted average load current is greater than or equal to the real-time load current, it means that the surface temperature of the grounding copper bar may rise in the future. Therefore, although the heating power of the heater 11 needs to be increased at this time, the heating power of the heater 11 may need to return to a lower level in the future. In some embodiments of the present application, the second adjustment coefficient is multiplied by the second preset parameter, wherein the second preset parameter is a positive number less than 1, so as to reduce the second adjustment coefficient, so that the degree of increase in the standard heating power can be appropriately reduced to cope with the future load current change trend in advance. If the predicted average load current is less than the real-time load current, it means that the surface temperature of the grounding copper bar may continue to decline in the future, so the second adjustment coefficient is kept unchanged.

[0061] In some embodiments of the present application, Figure 3 As shown, the power taking unit 12 includes a power taking coil 121 , a rectifying and voltage stabilizing module 122 and a DC / DC conversion module 123 .

[0062] The power taking coil 121 is configured to generate an induced voltage according to the operating magnetic field of the cable, wherein the coil plane of the power taking coil 121 is perpendicular to the cable line 20, and the cable line 20 passes through the center point of the coil plane; The input end of the rectifying and stabilizing module 122 is connected to the power taking coil 121, and the rectifying and stabilizing module 122 is configured to stabilize the induced voltage and output a first voltage signal U1; The DC / DC conversion module 123 is configured to perform voltage conversion on the first voltage signal U1 and output a second voltage signal U2 , so as to supply power to the heater 11 according to the second voltage signal U2 .

[0063] The embodiment of the present application obtains the induced voltage of the cable line 20 through the power taking coil 121, and performs voltage stabilization and voltage conversion on the induced voltage through the rectifier voltage stabilization module 122 and the DC / DC conversion module 123, which can effectively convert the induced voltage generated by the cable running magnetic field into a power source that can directly drive the heater 11, thereby providing a continuous and relatively independent power supply for the heater 11. Compared with the traditional method of using batteries to power the heater 11, the power taking unit 12 can directly obtain power from the running magnetic field of the tunnel cable, without the need to frequently enter the tunnel to open the grounding box for battery replacement, which is conducive to improving the endurance of the heater 11, reducing both the manpower maintenance cost and the power utilization rate, and the circuit structure is simple and low cost, thus greatly reducing the construction difficulty.

[0064] Specifically, Figure 3As shown, the cable line 20 takes the power coil vertically and passes through the center, and obtains an AC induced voltage on the coil, which is then rectified by the rectifier and voltage regulator circuit and the DC / DC conversion circuit to obtain a stable second voltage signal U2. The control chip 141 collects the rectified first voltage signal U1 and compares it with the first preset voltage. According to the comparison result, the rectifier output is adjusted using the thyristor control (Silicon Controlled Rectifier, SCR) to stabilize the first voltage signal U1 within the set range. The first voltage signal U1 is converted into a voltage through the DC / DC conversion module 123 and a second voltage signal U2 is output. The heater 11 is powered by the second voltage signal U2, so that the heater 11 can work at the target heating power.

[0065] Furthermore, the control unit 14 includes a first controllable switch S1 , a second controllable switch S2 , a third controllable switch S3 and a control chip 141 .

[0066] The first controllable switch S1 is connected between the DC / DC conversion module 123 and the heater 11, the second controllable switch S2 is connected between the battery 13 and the heater 11, and the third controllable switch S3 is connected between the DC / DC conversion module 123 and the battery 13; The first output end of the control chip 141 is connected to the control end of the first controllable switch S1, and the control chip 141 is configured to control the first controllable switch S1 to be closed when the temperature inside the grounding box is lower than the preset temperature; the first input end of the control chip 141 is connected to the output end of the DC / DC conversion module 123, and the second output end of the control chip 141 is connected to the control end of the second controllable switch S2. The control chip 141 is also configured to control the second controllable switch S2 to be closed when the second voltage signal U2 output by the DC / DC conversion module 123 is lower than the first preset voltage and the temperature inside the grounding box is lower than the preset temperature, so as to supply power to the heater 11 through the battery 13; the second input end of the control chip 141 is connected to the output end of the rectification and voltage regulation module 122, and the third output end of the control chip 141 is connected to the control end of the rectification and voltage regulation module 122. The control chip 141 is also configured to compare the first voltage signal output by the rectification and voltage regulation module 122 with the second preset voltage, and generate a control signal according to the comparison result and send it to the control end of the rectification and voltage regulation module 122.

[0067] The embodiment of the present application provides a battery 13 to ensure that the heater 11 can still be effectively powered when the induced voltage of the cable line 20 is insufficient, thereby ensuring the continuous operation of the heater 11 under special working conditions. Through dynamic switching between the power supply unit 12 and the battery 13, the reliability of the anti-condensation water device is improved while achieving reasonable distribution and flexible use of electric energy, thereby ensuring the stability of the anti-condensation water performance to the greatest extent.

[0068] In addition, the embodiment of the present application compares the first voltage signal U1 corresponding to the induced voltage with the second preset voltage through the control chip 141, and controls the rectification and voltage regulation module 122 to adjust according to the comparison result to achieve voltage regulation processing of the first voltage signal U1, thereby improving the power supply quality of the power taking unit 12.

[0069] Specifically, the control chip 141 collects the temperature inside the grounding box through the temperature sensor. When the temperature inside the box is lower than the set temperature T1, if the second voltage signal U2 output by the DC / DC conversion module 123 is greater than or equal to the first preset voltage, it indicates that the induced voltage is sufficient, so the first controllable switch S1 is controlled to close to start the heater to heat up the local temperature, convert the condensed water into water vapor and discharge it. And when the temperature inside the box reaches the set maximum temperature T2, the first controllable switch S1 is controlled to be disconnected to stop the heater 11 from working, so that the temperature inside the grounding box is always maintained within the range of T1~T2, and the control chip 141 controls the third controllable switch S3 to close, so as to charge the battery 13 using the DC / DC conversion module 123. If the second voltage signal U2 output by the DC / DC conversion module 123 is lower than the first preset voltage, it indicates that the induced voltage is insufficient, so the control chip 141 controls the second controllable switch S2 to close, so as to power the heater 11 through the battery 13.

[0070] Accordingly, please refer to Figure 4 An embodiment of the present application provides a grounding box 1, which includes a grounding copper bus 30, a box body 40, and an anti-condensation water device 10 according to the above embodiment, wherein the anti-condensation water device 10 is arranged inside the grounding box 1.

[0071] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0072] The grounding box 1 proposed in the embodiment of the present application maintains the temperature inside the box at the desired temperature and has a long-term endurance through the anti-condensation water device 10 arranged inside the grounding box 1. Therefore, while ensuring that the demand for evaporation of condensed water is met, the heating power of the anti-condensation water device 10 can be adaptively adjusted to avoid the anti-condensation water device 10 overheating the temperature inside the box and causing a waste of power supply energy, which greatly reduces unnecessary heating energy consumption and is conducive to the anti-condensation water device 10 to have a long-term endurance, thereby effectively avoiding grounding box failures caused by condensed water.

[0073] In some embodiments of the present application, Figure 5 As shown, the box body 40 includes a box cover 41 and a box bottom 42, and the box cover 41 and the box bottom 42 are connected by hinges and bolts, the grounding copper bus 30 is fixed to the box bottom 42 by metal fixings, and a temperature sensor 50 is arranged on the grounding copper bus 30.

[0074] At present, the cable grounding box in the tunnel is generally composed of an integrated non-detachable box body and a flat box cover, which are connected and fixed with multiple sets of bolts. When it is necessary to inspect the wiring terminals in the box and conduct test wiring in the grounding box, the operating space of the staff is small and the work is extremely inconvenient. Considering the convenience of working in the box, the embodiment of the present application proposes the following Figure 5 In the box structure shown, when it is necessary to perform wiring or maintenance work at the wiring terminals or the grounding copper bar, the bolts are first removed, and the box cover 41 can be opened outward with the hinge as the axis to provide sufficient operating space for the work inside the box. Therefore, the embodiment of the present application can provide sufficient operating space for the work inside the grounding box through the connection structure between the box cover and the box bottom, which is conducive to the maintenance work and improves the work efficiency.

[0075] Further, in some embodiments of the present application, Figure 5 As shown, a one-way breathing valve 411 is provided on the box cover 41, and the one-way breathing valve 411 is used to discharge water vapor converted from condensed water.

[0076] At present, most of the grounding boxes used in tunnels are not sealed, and the cable inlet and cover plate connection are interconnected with the outside world. The ambient humidity in the tunnel is also relatively high. If certain sealing measures are not taken, the air convection inside and outside the grounding box will be too fast, which will greatly reduce the dehumidification effect of the heater. Therefore, sealant is used to seal the cable inlet and the cover plate connection.

[0077] When the heater 11 in the grounding box 1 is working, the temperature in the box is stabilized between 35°C and 40°C, and the condensed water in the box evaporates due to heat and the temperature rises, resulting in a high air pressure in the box. In order to limit air convection while maintaining the air pressure balance inside and outside the grounding box, a one-way breathing valve 411 is installed on the box cover 41. When there is an air pressure difference between the inside and outside of the grounding box and the air pressure P1 inside the box is greater than the air pressure P2 outside the box, the gas passes from the inside of the box to the outside of the box through the breathing valve, and the air outside the box cannot enter, so the purpose of balancing the air pressure can be achieved. Therefore, the embodiment of the present application realizes the function of limiting air convection while maintaining the air pressure balance inside and outside the grounding box through the one-way breathing valve structure set on the box cover 41, thereby effectively improving the anti-condensation water effect.

[0078] In other embodiments of the present application, Figure 6 As shown, the anti-condensation water device 10 includes a heater 11, a power supply unit 12 and a control unit 14. Compared with the previous embodiment, the anti-condensation water device 10 in this embodiment is not provided with a battery 13, but the battery 13 is arranged outside the tunnel to improve the working safety of the grounding box in the tunnel.

[0079] The systems, devices, modules or units described in the above embodiments may be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, an industrial computer, a control terminal, or a combination thereof.

[0080] For the convenience of description, the above device is described in various units according to their functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0081] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0082] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0083] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

[0084] Although the embodiments of the present application have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A condensation water prevention device for a grounding box in a tunnel, characterized in that: The anti-condensation water device comprises: A heater, the heater is arranged on the inner side of the box body side plate of the grounding box, and the heater is used to heat the surrounding space of the grounding copper busbar in the grounding box to evaporate the condensed water in the grounding box; A power taking unit, which is arranged on the outside of the side plate of the box body and is configured to obtain the induced voltage of the cable line in the tunnel and supply power to the heater when the induced voltage is sufficient; a battery configured to supply power to the heater when the induced voltage is insufficient; A control unit, the control unit being configured to control at least one of the power taking unit and the battery to operate when the temperature inside the grounding box is lower than a preset temperature, and to control the power taking unit to charge the battery when the temperature inside the grounding box is not lower than a preset temperature; The control unit is configured to determine the standard heating power of the heater based on the temperature inside the box and the historical load current of the cable line, and adaptively adjust the standard heating power according to the real-time load current of the cable line to obtain the target heating power, so that the heater operates at the target heating power.

2. The anti-condensation water device according to claim 1, characterized in that: When the real-time load current of the cable line is greater than or equal to a first threshold, determining that the induced voltage is sufficient; In a case where the real-time load current of the cable line is less than the first threshold, it is determined that the induced voltage is insufficient.

3. The anti-condensation water device according to claim 2, characterized in that: The control unit is further configured to: When the historical load current of the cable line is greater than or equal to the first threshold, the surface temperature of the grounding copper bar is determined according to the historical load current of the cable line, and a thermal field simulation is performed according to the current temperature inside the grounding box, the surface temperature of the grounding copper bar and different heating powers, so as to determine the standard heating power according to the simulation results; When the historical load current of the cable line is less than the first threshold, thermal field simulation is performed according to the current temperature inside the grounding box and different heating powers, so as to determine the standard heating power according to the simulation result; The standard heating power is used to increase the temperature in the box and maintain it at a desired temperature.

4. The anti-condensation water device according to claim 3, characterized in that: In a case where the historical load current of the cable line is greater than or equal to the first threshold, the control unit is further configured to: Determine a change trend of the real-time load current according to the real-time load current and the historical load current, and obtain a load current fluctuation amount; In the case where the load current fluctuation amount is greater than or equal to a second threshold value, if the real-time load current shows an upward trend, a first adjustment coefficient is determined according to the difference between the load current fluctuation amount and the second threshold value, and the standard heating power is reduced according to the first adjustment coefficient to obtain the target heating power; if the real-time load current shows a downward trend, a second adjustment coefficient is determined according to the difference between the load current fluctuation amount and the second threshold value, and the standard heating power is increased according to the second adjustment coefficient to obtain the target heating power; And when the load current fluctuation amount is smaller than the second threshold value, the standard heating power is used as the target heating power.

5. The anti-condensation water device according to claim 1, characterized in that: The power taking unit comprises: A power taking coil, wherein the power taking coil is configured to generate the induced voltage according to the operating magnetic field of the cable line, wherein the coil plane of the power taking coil is perpendicular to the cable line, and the cable line passes through the center point of the coil plane; A rectifier and voltage regulator module, wherein an input end of the rectifier and voltage regulator module is connected to the power taking coil, and the rectifier and voltage regulator module is configured to perform voltage stabilization processing on the induced voltage and output a first voltage signal; A DC / DC conversion module is configured to perform voltage conversion on the first voltage signal and output a second voltage signal, so as to supply power to the heater according to the second voltage signal.

6. The anti-condensation water device according to claim 5, characterized in that: The control unit comprises: a first controllable switch connected between the DC / DC conversion module and the heater; A control chip, wherein a first output end of the control chip is connected to a control end of the first controllable switch, and the control chip is configured to control the first controllable switch to close when the temperature inside the grounding box is lower than a preset temperature.

7. The anti-condensation water device according to claim 6, characterized in that: The control unit also includes: a second controllable switch connected between the battery and the heater; The first input end of the control chip is connected to the output end of the DC / DC conversion module, and the second output end of the control chip is connected to the control end of the second controllable switch. The control chip is also configured to control the second controllable switch to close when the second voltage signal output by the DC / DC conversion module is lower than the first preset voltage and the temperature inside the grounding box is lower than the preset temperature, so as to power the heater through the battery.

8. The anti-condensation water device according to claim 6 or 7, characterized in that: The control unit also includes: The second input end of the control chip is connected to the output end of the rectifier and voltage regulator module, and the third output end of the control chip is connected to the control end of the rectifier and voltage regulator module. The control chip is also configured to compare the first voltage signal output by the rectifier and voltage regulator module with the second preset voltage, and generate a control signal according to the comparison result and send it to the control end of the rectifier and voltage regulator module.

9. A grounding box, characterized in that: The grounding box comprises: Grounding copper busbar; Box; And the anti-condensation water device according to any one of claims 1 to 8 above, wherein the anti-condensation water device is arranged inside the grounding box.

10. The grounding box according to claim 9, characterized in that: The box body includes a box cover and a box bottom, and the box cover and the box bottom are connected by hinges and bolts, and the grounding copper bar is fixed to the box bottom by a metal fixing piece; Wherein, a one-way breathing valve is arranged on the box cover, and the one-way breathing valve is used to discharge water vapor converted from condensed water.

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