阅读说明：本技术 油田专用油管加热集肤电伴热装置 (Oil pipe heating skin electric heat tracing device special for oil field ) 是由 赵海峰 顾秀斌 于 2021-08-18 设计创作，主要内容包括：本发明涉及油田稠油输油管路电加热技术领域,公开了油田专用油管加热集肤电伴热装置,包括电源控制柜和与电源控制柜电性连接的集肤加热管,其中调制输出电路包括市电整流滤波电路、直流变频降压隔离电路、二次直流变频调制交直流混合输出电路和安全输出控制电路,380V动力电经市电整流滤波电路成为直流高压电,经高频开关管控制、直流变频降压隔离电路和隔离转换经整流滤波为低压直流电,低压直流电经二次直流变频调制交直流混合输出电路输出；等电位检测电路,控制输出电压电流使等电位电信号加入下一个加热输出周期波形内,从而在不影响加热本身正常工作的情况下大幅度消除等电位差,进一步保护管线因等电位差造成的电解腐蚀情况。(The invention relates to the technical field of electric heating of oil delivery pipes of thick oil in oil fields, and discloses a skin electric heat tracing device for heating oil pipes special for oil fields, which comprises a power supply control cabinet and a skin heating pipe electrically connected with the power supply control cabinet, wherein a modulation output circuit comprises a mains supply rectification filter circuit, a direct current frequency conversion voltage reduction isolation circuit, a secondary direct current frequency conversion modulation alternating current-direct current hybrid output circuit and a safety output control circuit, 380V power electricity becomes direct current high voltage electricity through the mains supply rectification filter circuit, the direct current high voltage electricity is controlled by a high-frequency switch tube, the direct current frequency conversion voltage reduction isolation circuit and the isolation conversion are rectified and filtered into low voltage direct current, and the low voltage direct current is output through the secondary direct current frequency conversion modulation alternating current-direct current hybrid output circuit; the equipotential detection circuit controls the output voltage and current to enable an equipotential electrical signal to be added into a waveform of the next heating output period, so that the equipotential is greatly eliminated under the condition that the normal work of heating is not influenced, and the electrolytic corrosion condition of a pipeline caused by the equipotential is further protected.)

1. The utility model provides a special oil pipe heating skin electric heat tracing device in oil field, includes power control cabinet (1) and with power control cabinet (1) electric connection's skin heating pipe (2), skin heating pipe (2) by seamless steel pipe and an interface be 16mm skin heating cable composition, its characterized in that: the power control cabinet (1) comprises an automatic voltage-regulating isolation power supply: the mains supply is effectively isolated and reduced to a safe voltage, and electric shock is effectively prevented;

a modulation output circuit: reasonable working voltage, current and frequency are output according to the actual working environment of the site, and the working efficiency is improved;

the safety detection control circuit comprises: the device can effectively prevent overhigh voltage and current output and electric leakage, and simultaneously detect the faults of the oil pipe heating circuit, thereby ensuring the production safety;

a temperature control system: the operation and the output power of the whole machine are automatically controlled, so that the temperature is constant in a set range, and the power consumption is reduced;

equipotential detection circuit: the equipotential detection sensing line and the skin heating line are shared, and the modulation output circuit is used for detecting the equipotential in a voltage current duty cycle stage in the use characteristic of the heating current of the skin line;

the 380V power electricity becomes direct-current high-voltage electricity through the commercial power rectification filter circuit, the direct-current high-voltage electricity is controlled by the high-frequency switching tube, is rectified and filtered through the direct-current variable-frequency voltage reduction isolation circuit and isolation conversion to form low-voltage direct current, and the low-voltage direct current is output through the secondary direct-current variable-frequency modulation alternating-current and direct-current hybrid output circuit;

the grounding point at the near end of the skin heating wire of the equipotential detection circuit is the lower end of a protection tube shell RL, the high-frequency alternating current component filtered by R15/R16 resistor voltage division C6 at the upper end of the sampling point skin heating wire is sent to a CD4052 input end 13 pin, and then is led out from an 11 pin and a 12 pin to be sent to a CPU detection pin, output signals of the 11 pin and the 12 pin are controlled by a 9 pin and a 10 pin, the signals are taken from related output pins of the CPU and used for removing heating electric signals output by the local machine, and the equipotential signals from the far end collected by the skin heating wire are collected only in the period when the local machine does not output.

2. The oil field dedicated oil pipe heating skin electric heat tracing device according to claim 1, characterized in that: the skin heating cable is externally wrapped with a seamless steel pipe (3), the seamless steel pipe is a galvanized seamless steel pipe, and a zinc coating is made of zinc-nickel binary alloy, wherein the nickel component accounts for 1-3% of the total mass, and the nickel is formed in an electrolytic deposition mode and has high abrasion resistance and corrosion resistance; the insulating layer of the skin heating cable is made of high-temperature-resistant and wear-resistant materials.

3. The oil field dedicated oil pipe heating skin electric heat tracing device according to claim 1 or 2, characterized in that: the working principle of the safety output control circuit is that a power supply loop consisting of a control part power supply management chip drive G1, G2, G3 and G4 controls output voltage and protects 4 IGBTs, DL1 and DL2 are power supply management chip current sampling devices, R2, R3, R4 and D3 form an isolation direct-current voltage sampling circuit, a CPU can adjust isolation direct-current voltage according to an output program, the CPU controls and outputs IGBTG5, G6, G7 and G8 to enable voltage and current applied to a load skin heating wire RL to reach an ideal state, DL3, DL4, DL5 and DL6 are CPU voltage current sampling devices used for protecting the IGBTs and output characteristics, RT is an IGBT temperature measuring resistor, R5-R12 are CPU-to-IGBT driver isolation resistors, and a/b/c/D/e/f/G/h is an IGBT driver model number of QP12W 08-37A.

4. The oil field dedicated oil pipe heating skin electric heat tracing device according to claim 1 or 2, characterized in that: the commercial power rectification filter circuit rectifies three-phase 380V commercial power into direct current through a rectifier bridge D1, the direct current is charged into capacitors C1 and C2 through a direct current fuse DR and a starting resistor R1, when the voltage is detected by a CPU and is charged to more than 70%, the CPU outputs a signal to enable a triode GB to be conducted to a K1 contactor for attraction, and the direct current main power supply is conducted.

5. The oil field dedicated oil pipe heating skin electric heat tracing device according to claim 1 or 2, characterized in that: the working principle of the direct-current variable-frequency step-down isolation circuit is that main direct current drives a primary side of a high-frequency transformer through a double push-pull loop consisting of G1, G2, G3 and G4, and a secondary side of the transformer T is rectified by a high-speed rectifier bridge D to output isolated direct current.

6. The oil field dedicated oil pipe heating skin electric heat tracing device according to claim 1 or 2, characterized in that: the working principle of the secondary direct current frequency conversion modulation alternating current and direct current hybrid output circuit is that low-voltage direct current is filtered by C3, L, C4 and C5 and then is sent to a double push-pull loop consisting of G5, G6, G7 and G8 to be output to an RL skin heating wire for heating.

7. The oil field dedicated oil pipe heating skin electric heat tracing device according to claim 1 or 2, characterized in that: the modulation output circuit is provided with a plurality of direct current power supplies, and the direct current power supplies adopt a 3842 combined power supply IGBT switching transformer to supply power to a CPU power supply management chip and a driver.

8. The oil field dedicated oil pipe heating skin electric heat tracing device according to claim 1 or 2, characterized in that: the modulation output circuit is provided with a 458 communication end, and the 458 communication end can realize information and control signal transmission of an upper computer, a local operation panel and wired and wireless remote transmission.

9. The oil field dedicated oil pipe heating skin electric heat tracing device according to claim 1 or 2, characterized in that: the modulation output circuit optimizes an equipotential detection circuit structure, an equipotential detection sensing line and a skin heating line are shared, the circuit is used for detecting equipotential in a voltage and current duty phase in the use characteristic of the heating current of the skin line, the equipotential is transmitted to a CPU (central processing unit) for calculation through detection operation, isolation and amplification, then the output voltage and the output current are controlled, so that an equipotential electric signal is added into the waveform of the next heating output period, and the equipotential is greatly eliminated under the condition that the normal work of the heating is not influenced.

10. The oil field dedicated oil pipe heating skin electric heat tracing device according to any one of claims 1 to 9, characterized in that: each group of heating units of the skin heating pipe (2) is 1m, and the temperature maintaining power is divided into three series of 20W, 30W and 50W per extension meter according to different specifications of the heating pipe.

Technical Field

The invention relates to the technical field of electric heating of oil pipelines of thick oil in oil fields, in particular to an oil pipe heating skin electric heat tracing device special for the oil fields.

Background

The skin heating and heat tracing band heating technology of the existing pipeline is a heating method which is always used in a metal pipeline heat tracing system in recent years.

The prior electric heating technical route has the following defects: for example, CN206439554U discloses a device for realizing automatic heat tracing and blockage removal of a ground pipeline by using a skin effect, which has the advantages of large heating power loss of a heat tracing band, short applicable distance, high failure rate, and low safety factor (power supply is generally commercial power, and electric shock hidden danger exists); skin heating is divided into two parts: the low-frequency skin heating volume is heavy, the heat power consumption is large, the efficiency is low, and the safety factor is low (non-safety voltage power supply has electric shock safety hidden trouble). Refer to fig. 1. For example, CN208934659U, CN2602155Y, CN110139412A, etc. disclose related techniques for skin heating, which solve the problems of safety and low efficiency of ac mains supply, but the above-mentioned related problems still exist, such as severe electrolytic corrosion of skin protection pipelines due to equipotential problem, short applicable distance of intermediate frequency skin heating, and high cost.

Disclosure of Invention

The invention aims to provide a skin electric heat tracing device for heating an oil pipe special for an oil field, which comprises a power supply control cabinet and a skin heating pipe electrically connected with the power supply control cabinet, greatly reduces the equipotential of the heating pipe, effectively solves the electrolytic corrosion of a metal pipeline caused by the equipotential problem, and simultaneously can ensure the electric safety, thereby solving the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: oil pipe heating skin electric heat tracing device special for oil field, including power control cabinet and with power control cabinet electric connection's skin heating pipe, the skin heating pipe comprises galvanized seamless steel pipe and a 16mm skin heating cable, the power control cabinet includes, automatic voltage regulation isolation power supply: the mains supply is effectively isolated and reduced to a safe voltage, and electric shock is effectively prevented;

a modulation output circuit: reasonable working voltage, current and frequency are output according to the actual working environment of the site, and the working efficiency is improved;

the safety detection control circuit comprises: effectively prevent voltage, electric current output too high and electric leakage, detect oil pipe heating circuit trouble simultaneously. The production safety is guaranteed;

a temperature control system: the operation and the output power of the whole machine are automatically controlled, so that the temperature is constant in a set range, and the power consumption is reduced;

equipotential detection circuit: the equipotential detection sensing line and the skin heating line are shared, and the modulation output circuit is used for detecting the equipotential in a voltage current duty cycle stage in the use characteristic of the heating current of the skin line;

the 380V power electricity becomes direct-current high-voltage electricity through the commercial power rectification filter circuit, the direct-current high-voltage electricity is controlled by the high-frequency switching tube, is rectified and filtered through the direct-current variable-frequency voltage reduction isolation circuit and isolation conversion to form low-voltage direct current, and the low-voltage direct current is output through the secondary direct-current variable-frequency modulation alternating-current and direct-current hybrid output circuit;

the grounding point at the near end of a skin heating wire of the equipotential detection circuit is the lower end of a protection tube shell RL, the high-frequency alternating current component filtered by R15/R16 resistor voltage division C6 at the upper end of the sampling point skin heating wire is sent to a CD4052 input end 13 pin, and then is led out from an 11 pin and a 12 pin to be sent to a CPU detection pin, output signals of the 11 pin and the 12 pin are controlled by a 9 pin and a 10 pin, the signals are taken from related output pins of the CPU and used for removing heating electric signals output by the local machine, and the equipotential signals from the far end collected by the skin heating wire are collected only in the period when the local machine does not output.

Furthermore, the skin heating cable is externally wrapped with a seamless steel pipe, the seamless steel pipe is a galvanized seamless steel pipe, and the galvanized layer is made of zinc-nickel binary alloy, wherein the nickel component accounts for 1-3% of the total mass, and the nickel component is formed in an electrolytic deposition mode and has high abrasion resistance and corrosion resistance; the insulating layer of the skin heating cable is made of high-temperature-resistant and wear-resistant materials.

Furthermore, the working principle of the safety output control circuit is that a power supply loop consisting of partial power management chip drivers G1, G2, G3 and G4 is controlled to output voltage and protect 4 IGBTs, DL1 and DL2 are power management chip current sampling devices, R2, R3, R4 and D3 form an isolated direct current voltage sampling circuit, a CPU can adjust the isolated direct current voltage according to an output program, the CPU controls outputs IGBTG5, G6, G7 and G8 to enable the voltage and the current applied to a load skin heating wire RL to reach an ideal state, DL3, DL4, DL5 and DL6 are CPU voltage current sampling devices for protecting the IGBTs and output characteristics, RT is an IGBT temperature measuring resistor, R5-R12 is a CPU-IGBT driver isolating resistor, and a/b/c/D/e/f/G/h is an IGBT driver model number 12W 08S-37A.

Further, the mains supply rectification filter circuit rectifies the three-phase 380V mains supply into direct current through the rectifier bridge D1, the direct current is charged into the capacitors C1 and C2 through the direct current fuse DR and the starting resistor R1, when the voltage is detected by the CPU to be more than 70%, the CPU outputs a signal to enable the triode GB to be conducted to the K1 contactor for attraction, and the direct current main power supply is conducted.

Furthermore, the working principle of the direct current variable-frequency step-down isolation circuit is that main direct current drives a primary side of a high-frequency transformer through a double push-pull loop consisting of G1, G2, G3 and G4, and a secondary side of the transformer T is rectified by a high-speed rectifier bridge D to output isolated direct current.

Further, the working principle of the secondary direct current frequency conversion modulation alternating current and direct current hybrid output circuit is that low-voltage direct current is filtered by C3, L, C4 and C5 and then is sent to a double push-pull loop consisting of G5, G6, G7 and G8 to be output to an RL skin heating wire for heating.

Furthermore, the modulation output circuit is provided with a plurality of direct current power supplies, and the direct current power supplies adopt 3842 combined power supply IGBT switching transformer to supply power to the CPU power management chip and the driver.

Furthermore, the modulation output circuit is provided with a 458 communication end, and the 458 communication end can realize information and control signal transmission of an upper computer, a local operation panel and wired and wireless remote transmission.

Furthermore, an output modulation circuit optimizes the structure of the equipotential detection circuit, an equipotential detection sensing line and a skin heating line are shared, the circuit is used for detecting equipotential in a voltage and current duty phase in the use characteristic of the heating current of the skin heating line, the equipotential is transmitted to a CPU (central processing unit) for calculation through detection operation, isolation and amplification, and then output voltage and current are controlled to enable an equipotential electric signal to be added into the waveform of the next heating output period, and the equipotential is greatly eliminated under the condition that the normal work of heating is not influenced.

Furthermore, each group of heating units of the skin heating pipe is 1m, and the temperature maintaining power is divided into three series of 20W, 30W and 50W per extension meter according to different specifications of the heating pipe.

Compared with the prior art, the invention has the following beneficial effects:

1. the invention provides an oil pipe heating skin electric tracing device special for an oil field, which collects a far-end equipotential signal collected from a skin heating wire by arranging an equipotential detection circuit, detects the equipotential signal at a voltage current duty stage in the use characteristic of heating current of the skin heating wire, and controls output voltage current after the equipotential signal is sent to a CPU (central processing unit) for calculation through detection operation, isolation and amplification so as to add the equipotential signal into a waveform of the next heating output period, thereby greatly eliminating the equipotential signal under the condition of not influencing the normal work of heating and further protecting the electrolytic corrosion condition of a pipeline caused by the equipotential.

2. The skin heating cable is externally wrapped with a seamless steel pipe, the seamless steel pipe is a galvanized seamless steel pipe, a zinc coating is made of zinc-nickel binary alloy, wherein the nickel component accounts for 1-3% of the total mass, and the skin heating cable is formed in an electrolytic deposition mode and has high abrasion resistance and corrosion resistance; the insulating layer of the skin heating cable is made of high-temperature-resistant and wear-resistant materials, the service life of the skin heating cable can be greatly prolonged, the cost is reduced, and the skin heating cable is one of important creative contributions of the applicant.

3. Meanwhile, a commercial power rectifying and filtering circuit, a direct-current variable-frequency step-down isolating circuit, a secondary direct-current variable-frequency modulation alternating-current and direct-current hybrid output circuit and a safe output control circuit are arranged in the modulation output circuit, a high-frequency transformer is used for replacing a low-frequency transformer to carry out power isolation, the size is effectively reduced, the weight is reduced, the safe voltage power supply effectively prevents electric shock accidents, the alternating-current and direct-current components are controlled and output by an intelligent chip to enable the skin heating wire to fully exert the heat effect, and therefore the heating purpose is achieved.

Drawings

FIG. 1 is a schematic diagram of a prior art skin heating technique;

FIG. 2 is a schematic structural view of the skin electric heat tracing device for heating oil pipe dedicated for oil field of the present invention;

FIG. 3 is a schematic structural diagram of the skin electric heat tracing device for heating oil pipes specially used for oil fields;

FIG. 4 is a schematic diagram of a modulation output circuit of the skin electric heat tracing device for heating oil pipes specially used for oil fields according to the present invention;

FIG. 5 is a schematic diagram of an equipotential detecting circuit of the skin electric heat tracing apparatus for heating oil pipes dedicated for oil fields according to the present invention;

FIG. 6 is a peripheral schematic diagram of an IGBT driver QP12W08S-37A of the skin electric heat tracing device for heating oil pipes special for oil fields.

In the figure: 1. a power supply control cabinet; 2. a skin heating pipe; 3. seamless steel pipe.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 2-6, the oil pipe heating skin electric heat tracing device for oil field comprises a power control cabinet 1 and a skin heating pipe 2 electrically connected with the power control cabinet 1, wherein the skin heating pipe 2 is composed of a galvanized seamless steel pipe and a 16mm skin heating cable, each group of heating units of the skin heating pipe 2 is 1m, the temperature and power are divided into three series of 20W, 30W and 50W per extension meter according to different specifications of the heating pipe, the skin heating cable is externally wrapped with a seamless steel pipe 3, and the power control cabinet 1 comprises an automatic voltage regulation isolation power supply: the mains supply is effectively isolated and reduced to a safe voltage, and electric shock is effectively prevented;

a modulation output circuit: reasonable working voltage, current and frequency are output according to the actual working environment of the site, and the working efficiency is improved;

the safety detection control circuit comprises: effectively prevent voltage, electric current output too high and electric leakage, detect oil pipe heating circuit trouble simultaneously. The production safety is guaranteed;

a temperature control system: the operation and the output power of the whole machine are automatically controlled, so that the temperature is constant in a set range, and the power consumption is reduced;

equipotential detection circuit: the equipotential detection sensing line and the skin heating line are shared, and the modulation output circuit is used for detecting the equipotential in a voltage current duty cycle stage in the use characteristic of the heating current of the skin line;

the 380V power electricity becomes direct-current high-voltage electricity through the commercial power rectification filter circuit, the direct-current high-voltage electricity is controlled by the high-frequency switching tube, is rectified and filtered through the direct-current variable-frequency voltage reduction isolation circuit and isolation conversion to form low-voltage direct current, and the low-voltage direct current is output through the secondary direct-current variable-frequency modulation alternating-current and direct-current hybrid output circuit;

referring to fig. 5, the grounding point at the near end of the skin heating wire of the equipotential detection circuit is the lower end of the protective tube housing RL, the high frequency ac component filtered by the R15/R16 resistor voltage dividing C6 at the upper end of the skin heating wire at the sampling point is sent to the input terminal 13 of the CD4052, and is led out from the pins 11 and 12 to the CPU detection pin, the output signals of the pins 11 and 12 are controlled by the pin 9 and pin 10, the signals are taken from the relevant output pins of the CPU to remove the heating electrical signals output by the local machine, the far-end equipotential signals collected by the skin heating wire are collected only in the period when the local machine does not output, and the electrolytic corrosion of the pipeline caused by equipotential is further protected.

Furthermore, the skin heating cable is externally wrapped with a seamless steel pipe, the seamless steel pipe is a galvanized seamless steel pipe, a zinc coating is made of zinc-nickel binary alloy, wherein the nickel component accounts for 1-3%, preferably 2% of the total mass, the nickel is formed in an electrolytic deposition mode, the wear resistance and the corrosion resistance are high, the effect is at least improved by more than 50% compared with the prior art through tests, and the comprehensive evaluation of thermal effect, service life and the like is realized; the insulating layer of skin heating cable make by high temperature resistant, wear-resisting material, insulating material can select fluoroplastics or ceramic silicon rubber, it has good performance, its life can be improved greatly in the setting of above-mentioned structure, reduce cost, the insulating layer can set up a plurality ofly moreover, all sets up in the cable core outside. In addition, ZnO (zinc oxide) can be selectively added into the cable core in the cable, the excellent skin effect of the zinc oxide is utilized to increase the concentrated generation of heat, the heating effect can be greatly improved, and glass fiber and mica tape are woven outside the cable core.

In addition, the sealing quality of the heat-tracing pipe junction box and the sealing of the terminal are also selected to be proper sealing materials, and the heat-tracing pipe junction box can work for a long time under the environment of water, high temperature and high pressure.

Please refer to fig. 4, the working principle of the safety output control circuit is to control a power circuit composed of partial power management chip drivers G1, G2, G3, and G4 to control the output voltage and protect 4 IGBTs, DL1 and DL2 are power management chip current sampling devices, R2, R3, R4, and D3 are isolated dc voltage sampling circuits, the CPU can adjust the isolation direct current voltage according to an output program, the CPU controls and outputs IGBTG5, G6, G7 and G8 to enable the voltage and the current applied to the load skin heating wire RL to reach an ideal state, DL3, DL4, DL5 and DL6 are CPU voltage and current sampling devices used for protecting the IGBT and output characteristics, RT is an IGBT temperature measuring resistor, R5-R12 are isolation resistors from the CPU to an IGBT driver, and a/b/c/d/e/f/G/h is an IGBT driver model QP12W 08S-37A.

The commercial power rectification filter circuit rectifies three-phase 380V commercial power into direct current through a rectifier bridge D1, the direct current is used for charging capacitors C1 and C2 through a direct current fuse DR and a starting resistor R1, when the voltage is charged to more than 70% through CPU detection voltage, a signal is output by a CPU, a triode GB is conducted to a K1 contactor for attraction, and the direct current main power supply is conducted.

The working principle of the direct-current variable-frequency step-down isolation circuit is that main direct current drives a primary side of a high-frequency transformer through a double push-pull loop consisting of G1, G2, G3 and G4, and a secondary side of the transformer T is rectified by a high-speed rectifier bridge D to output isolated direct current.

The working principle of the secondary direct current frequency conversion modulation alternating current and direct current hybrid output circuit is that low-voltage direct current is filtered by C3, L, C4 and C5 and then is sent to a double push-pull loop consisting of G5, G6, G7 and G8 to be output to an RL skin heating wire for heating.

Preferably, the modulation output circuit is provided with a plurality of direct current power supplies, each direct current power supply adopts a 3842 combined power supply IGBT switching transformer to supply power to the CPU power management chip and the driver, in addition, the modulation output circuit is provided with a 458 communication end, and the 458 communication end can realize information and control signal transmission of an upper computer, a local operation panel and wired and wireless remote transmission, realize remote monitoring and output control, and simultaneously improve the power utilization efficiency and reduce the fault rate.

Furthermore, the modulation output circuit optimizes the structure of the equipotential detection circuit, an equipotential detection sensing line and a skin heating line are shared, the circuit is used for detecting equipotential in a voltage current duty phase in the use characteristic of the heating current of the skin heating line, the equipotential is transmitted to a CPU (central processing unit) for calculation through detection operation, isolation and amplification, and then the output voltage current is controlled to enable an equipotential electric signal to be added into the waveform of the next heating output period, so that the equipotential is greatly eliminated under the condition that the normal work of the heating is not influenced.

Preferably, each group of heating units of the skin heating pipe 2 is 1m, and the temperature maintaining power is divided into three series of 20W, 30W and 50W per extension meter according to different specifications of the heating pipe.

In summary, the following steps: the invention provides a heating skin electric tracing device of an oil pipe special for an oil field, which collects a far-end equipotential signal collected from a skin heating wire by arranging an equipotential detection circuit, detects the equipotential signal at a voltage current duty stage in the use characteristic of heating current of the skin heating wire, and controls output voltage current after the equipotential signal is sent to a CPU (central processing unit) for calculation through detection operation, isolation and amplification so as to add the equipotential signal into a waveform of the next heating output period, thereby greatly eliminating the equipotential signal under the condition of not influencing the normal work of the heating per se and further protecting the electrolytic corrosion condition of the pipeline caused by the equipotential signal; meanwhile, a commercial power rectifying and filtering circuit, a direct-current variable-frequency step-down isolating circuit, a secondary direct-current variable-frequency modulation alternating-current and direct-current hybrid output circuit and a safe output control circuit are arranged in the modulation output circuit, a high-frequency transformer is used for replacing a low-frequency transformer to carry out power isolation, the size is effectively reduced, the weight is reduced, the safe voltage power supply effectively prevents electric shock accidents, the alternating-current and direct-current components are controlled and output by an intelligent chip to enable the skin heating wire to fully exert the heat effect, and therefore the heating purpose is achieved.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.