An intrinsically safe grounding resistance on-line monitoring device

Abstract

The utility model discloses an intrinsic safety type grounding resistance on -line monitoring device, intrinsic safety type grounding resistance on -line monitoring device contains explosion -proof casing, power unit, control unit. Explosion -proof casing uses cast -iron explosion -proof casing or cast -aluminum explosion -proof casing, and power unit and control unit are installed in the explosion -proof casing, and power unit contains voltage stabilizing module and excitation current module, and respectively is control unit and grounding resistance measuring circuit power supply, and power unit passes through control and brings the energy of explosion dangerous area, and makes intrinsic safety type grounding resistance on -line monitoring loop reach intrinsic safety explosion -proof requirement, and control unit measures voltage measuring pole and current measuring pole's data, and microprocessor records and handles data, and serial communication element will data transmission give host computer. The utility model discloses adopting intrinsic safety type power supply design, can realize all day real -time on -line monitoring grounding resistance of grounding down lead, can effectively shorten the measurement period, can carry out the continuity monitoring to grounding resistance, reduces the artificial maintenance of equipment.

Description

Technical Field

[0001] This utility model relates to the field of monitoring device technology, and more specifically to an intrinsically safe online monitoring device for grounding resistance. Background Technology

[0002] Lightning-induced fires and explosions cause severe property damage and casualties, and lightning disasters have been listed as one of the top ten natural disasters. Online grounding resistance monitoring devices are commonly used in industries such as industrial, power, telecommunications, and rail transportation. Especially in fire and explosion-proof locations such as petrochemical and oil and gas storage and transportation facilities, the requirements for lightning protection grounding measures are more stringent. The grounding resistance of the lightning protection grounding down conductor must meet lightning protection requirements to ensure that lightning is quickly discharged into the ground in the event of a lightning strike, effectively protecting personal and equipment safety. The petrochemical and oil and gas storage and transportation industries have extremely high requirements for grounding resistance monitoring, demanding both measurement accuracy and compliance with intrinsic safety and explosion-proof certification requirements.

[0003] Currently, the grounding resistance of down conductors is generally measured using the "three-electrode method," and this is done manually and periodically, with measurement intervals of four to six months. This manual, periodic "three-electrode method" cannot meet the explosion-proof requirements of hazardous areas, nor can it provide continuous monitoring of the measured object. Furthermore, it suffers from the problem of a large workload. For online monitoring of grounding down conductors in the petrochemical and oil and gas storage and transportation industries, how to prevent fires and explosions, ensure the inherent safety of the monitoring process, and achieve real-time online monitoring of grounding resistance has become an urgent problem to be solved. Utility Model Content

[0004] To solve the above-mentioned technical problems, or at least partially solve them, this disclosure provides an intrinsically safe online grounding resistance monitoring device. It adopts intrinsically safe real-time online grounding resistance monitoring technology, which improves the explosion-proof safety factor in the grounding resistance monitoring process and solves the drawbacks of traditional manual measurement.

[0005] To achieve the above objectives, this utility model provides an intrinsically safe online grounding resistance monitoring device, the specific technical solution of which is as follows: Power supply unit (b) is powered by a 24V intrinsically safe power supply 110 installed in a non-explosive hazardous area. The transformer chip of power supply unit (b) converts the voltage into multiple levels to power various parts of the circuit. The first path uses a step-down regulator module 206 to reduce the 24VDC power supply to a 3.5~5VDC (adjustable) regulated power supply to power the control unit (c) circuit; the second path uses an excitation current module 202 to convert the DC power supply into a constant current of 100~200mA (adjustable) as the grounding resistance measurement power supply, ensuring that the energy entering the hazardous area is less than 2W and stabilizing the output value.

[0006] Optionally, the power supply unit (b) is equipped with an electronic current limiting element (402) and a physical fuse element (401) to enable the monitoring device to have overcurrent protection, lightning protection, and reverse connection protection functions, so as to protect the normal operation of the monitoring device.

[0007] The control unit (c) includes a microprocessor 201, a voltage analog-to-digital converter 204, a current analog-to-digital converter 203, a serial communication element 105, an indicator element 205, a current measurement 102, and a voltage measurement 103.

[0008] Optionally, the microprocessor 201 has programmable, signal input, signal output, and data processing functions.

[0009] Optionally, the microprocessor 201 inputs an adjustable duty cycle PWM signal to the power supply unit (b) to adjust the first output voltage and the second output current of the power supply unit (b).

[0010] Optionally, the voltage analog-to-digital converter 204 converts the voltage data of the voltage measuring electrode 108 from analog to digital and inputs the data into the microprocessor 201.

[0011] Optionally, the current analog-to-digital converter 203 converts the current data of the current measuring electrode 109 from an analog quantity to a digital quantity and inputs the data into the microprocessor 201.

[0012] Optionally, the serial communication element 105 can transmit the data of the microprocessor 201 to the host computer 111, and the data is stored by the host computer 111.

[0013] Optionally, the indicator element 205 includes a display indicator element 501, an audio indicator element 502, and a physical button 503, which can display the real-time value of grounding resistance, alarm status, and parameter settings.

[0014] Optionally, the display indicator element 501 is a 128*128 LED display screen, which can display the real-time grounding resistance value and display alarm prompts.

[0015] Optionally, the sound indicator element 502 provides an audible alert when there is an alarm message.

[0016] Optionally, the physical button 503 is used to set relevant parameters.

[0017] Optionally, the current measuring 102 measures the current value of the current measuring electrode 109.

[0018] Optionally, the voltage measuring 103 measures the voltage value of the voltage measuring electrode 108.

[0019] The explosion-proof housing (a) is provided, and the power supply unit (b) and control unit (c) are both located inside the explosion-proof housing (a).

[0020] In the above technical solution, the intrinsically safe online grounding resistance monitoring device provided by this utility model has the following advantages compared with the prior art: The explosion-proof type of this utility model is intrinsically safe. The intrinsically safe design ensures that explosive gases will not be ignited in flammable and explosive environments (such as petroleum, chemical and mining) by limiting the energy of the circuit (voltage and current). Traditional devices may require additional explosion-proof enclosures or isolation measures, which are costly and bulky.

[0021] This utility model employs a low-power circuit and a special protection mechanism to isolate the energy between the dangerous area and the non-dangerous area, thus avoiding the electrical sparks generated by short circuits or malfunctions in traditional monitoring devices.

[0022] This invention can monitor changes in grounding resistance in real time and immediately alarm when abnormalities (such as corrosion or breakage) are detected, while traditional methods rely on periodic manual testing (such as megohmmeter testing) and cannot detect sudden failures. Attached Figure Description

[0023] Figure 1 An installation diagram provided for an embodiment of this utility model; Figure 2 A schematic diagram of the circuit structure provided for an embodiment of this utility model; Figure 3 A schematic diagram of the internal circuit of the power supply unit (b) provided in an embodiment of this utility model; Figure 4 A schematic diagram of the indicator element structure provided in an embodiment of this utility model; Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0025] To enable those skilled in the art to more clearly understand the above-mentioned objectives, features, and advantages of this disclosure, the solutions of this disclosure will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0026] Numerous specific details are set forth in the following description in order to provide a full understanding of this disclosure, but this disclosure may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some, and not all, of the embodiments of this disclosure.

[0027] Figure 1This invention provides an installation schematic diagram of an intrinsically safe online grounding resistance monitoring device according to an embodiment of the present invention. Figure 2 This is a circuit structure diagram of an intrinsically safe online grounding resistance monitoring device provided for an embodiment of this utility model. (Combined with...) Figure 1 and Figure 2 The intrinsically safe online grounding resistance monitoring device includes a control unit 101, a voltage measuring electrode 108, and a current measuring electrode 109. The control unit 101 includes a microprocessor 201, a power supply unit (b), a serial communication element 105, a monitoring unit 104, a voltage measuring electrode 103, a current measuring electrode 102, and an indicating element 205, and is housed within an explosion-proof enclosure (a). The control unit 101, voltage measuring electrode 108, and current measuring electrode 109 are installed in an explosion hazard zone. The power supply unit (b) corresponds to the intrinsically safe power supply 111 located in a safe zone. The serial communication element 105 corresponds to the host computer 111 located in a safe zone. The monitoring unit 104 is configured to correspond to the grounding lead 106 of the storage tank 107, the voltage measuring electrode 103 corresponds to the voltage measuring electrode 108, and the current measuring electrode 102 corresponds to the current measuring electrode 109.

[0028] Specifically, the intrinsically safe power supply 111, installed in a non-explosion-hazardous area, provides 24VDC power to the entire intrinsically safe online grounding resistance monitoring device and provides power isolation. The transformer chip of power supply unit (b) converts the voltage into multiple levels to power various parts of the circuit. The step-down regulator module 206 reduces the 24VDC power to a regulated 3.5~5VDC voltage to power the control unit (c) circuit. The constant current module 202 converts the 24VDC into a constant current of 100~200mA (adjustable) as the measurement current, ensuring that the energy entering the hazardous area is less than 2W and stabilizing the output value.

[0029] Specifically, the current from the constant current module 202 flows into the grounding lead 106 of the storage tank 107 through the monitoring component 104, passes through the grounding grid, and forms a current loop with the current measuring electrode 109. Additionally, the voltage measuring device 103 measures the voltage between the grounding lead 106 and the voltage measuring electrode 108. The microprocessor 201 records the voltage and current values ​​and calculates their ratio to determine the grounding resistance value of the grounding lead 106.

[0030] Figure 3 This is a schematic diagram of the internal circuit of the power supply unit (b) in an embodiment of the present invention, which includes a step-down voltage regulator module 206, an excitation current module 202, an electronic current limiting element 402, and a physical fuse element 401.

[0031] Specifically, the step-down regulator module 206 reduces the 24VDC power supply to 3.5~5VDC through the BUCK step-down circuit. The output voltage level is controlled by the duty cycle of the PWM signal output by the microprocessor 201, which enables the monitoring device to have overcurrent protection, lightning protection, and reverse connection protection functions, thus protecting the normal operation of the monitoring device.

[0032] Specifically, the constant current module 202 obtains the voltage through a voltage divider diode, and the constant current value can be adjusted by adjusting the resistance value of the voltage divider resistor. The current value can be controlled between 100 and 200mA, and the current magnitude is controlled by the PWM signal output by the microprocessor 201.

[0033] Figure 4 This is a schematic diagram of the structure of the indicator element 205 provided in an embodiment of the present invention. The indicator element 205 includes a display indicator element 501, a sound indicator element 502, and a physical button 503. The display indicator element 501, the sound indicator element 502, and the physical button 503 can be disposed on the top or side of the housing of the control component 101 to facilitate the viewing of the status and setting of parameters by relevant personnel. For example, the display indicator element can be a digital display composed of LEDs.

[0034] Specifically, the display indicator 501 can display the real-time value of the grounding resistance, system operating status, system alarm code, alarm status, and parameter settings. The sound indicator 502 emits a buzzer alarm when an alarm is detected. The physical buttons 503 can adjust parameters such as voltage, current, and alarm value.

[0035] Optionally, the control unit 101 can be connected to the host computer 111 via a wired or wireless connection. The control unit 101 is used to transmit resistance monitoring data to the host computer 111. Specifically, the host computer 111 can be a personnel monitoring platform, and the control unit 101 can be connected to the host computer 111 via a cable. The wired connection method can be RS485, and the communication protocol can be the MODBUS RTU protocol. The host computer 111 can view the resistance monitoring data in real time and store historical grounding resistance data for easy access by technicians.

[0036] This allows the total power consumption of the online grounding resistance monitoring device to be between 1W and 2W, controlling the energy introduced into the explosion hazard zone and ensuring that the entire online grounding resistance monitoring circuit meets intrinsically safe explosion-proof requirements. Simultaneously, it enables real-time, 24 / 7 online monitoring of the grounding resistance of the grounding down conductor 106 of storage tank 107, effectively shortening the measurement cycle and allowing for continuous monitoring of grounding resistance without the need for manual equipment maintenance, significantly saving manpower and resources. It can also promptly detect faults such as excessive grounding resistance in the lightning protection grounding down conductor 106 caused by corrosion or other environmental factors, as well as the location of potential safety hazards, providing alarm information and thus promptly eliminating the dangers posed by lightning to storage tanks, ensuring the safe operation of storage tanks in the petrochemical and oil and gas storage and transportation industries.

Claims

1. An intrinsically safe online grounding resistance monitoring device, which can be used for online monitoring of grounding resistance in explosion-hazardous areas, characterized in that, The intrinsically safe online grounding resistance monitoring device includes: an explosion-proof housing (a), a power supply unit (b), and a control unit (c); The explosion-proof enclosure (a) is installed in an explosion hazard zone and includes a cast iron explosion-proof enclosure or a cast aluminum explosion-proof enclosure; The power supply unit (b) includes a step-down voltage regulator module (206), an excitation current module (202), an electronic current limiting element (402), and a physical fuse element (401). The control unit (c) includes a microprocessor (201), a current measurement (102), a voltage measurement (103), a serial communication element (105), a current analog-to-digital converter (203), a voltage analog-to-digital converter (204), and an indicator element (205).

2. The intrinsically safe online grounding resistance monitoring device according to claim 1, characterized in that: The explosion-proof enclosure (a) is installed in an explosion hazard zone, and the power supply unit (b) and control unit (c) are both located inside the explosion-proof enclosure (a).

3. The intrinsically safe online grounding resistance monitoring device according to claim 1, characterized in that: The power supply unit (b) is connected to the intrinsically safe power supply (110) in the non-explosive hazardous area. The step-down voltage regulator module (206) converts the 24VDC power supply into a 3.5~5VDC regulated power supply. The excitation current module (202) converts the DC power supply into a constant small current so that the energy entering the hazardous area is less than 2W and the output value is stable.

4. The intrinsically safe online grounding resistance monitoring device according to claim 1, characterized in that: The electronic current limiting element (402) and the physical fuse element (401) enable the monitoring device to have overcurrent protection, lightning protection, and reverse connection protection functions to protect the normal operation of the monitoring device.

5. The intrinsically safe online grounding resistance monitoring device according to claim 1, characterized in that: The control unit (c) can be easily programmed, effectively measure various data, and perform data processing in the microprocessor (201). Data is uploaded through the serial communication element (105), and the real-time value of grounding resistance, alarm status, and parameter settings can be displayed through the indicator element (205).

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