CN201218804Y - Resistor method on-line corrosion monitoring instrument for high pressure gas pipeline - Google Patents
Resistor method on-line corrosion monitoring instrument for high pressure gas pipeline Download PDFInfo
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- CN201218804Y CN201218804Y CNU2008201086349U CN200820108634U CN201218804Y CN 201218804 Y CN201218804 Y CN 201218804Y CN U2008201086349 U CNU2008201086349 U CN U2008201086349U CN 200820108634 U CN200820108634 U CN 200820108634U CN 201218804 Y CN201218804 Y CN 201218804Y
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Abstract
The utility model relates to an on-line corrosion monitor for a high-pressure natural gas pipeline with an electric resistance method, which is applied for on-line corrosion monitoring for temperature compensation in a natural gas pipeline, and is characterized in that a single chip machine is arranged in the shell of the monitor, and respectively connected with a real-time clock, a data memory, an interface and a voltage stabilizer which is connected with a lithium cell. The single chip machine is respectively connected with two converters which are respectively connected with an amplifier. The two amplifiers are respectively connected with a resistance probe through a lead. The resistance probe is connected with an alternating constant current source. The utility model has the advantages: the on-line corrosion monitor uses AC signals as excitation signals to monitor, compensates the drift of thermoelectric force of nodes through measuring the specific value of electric potential difference of electric current at each node of the probe under different phases, completely compensates the electrical potential at the nodes through changing the current direction of the excitation constant current source, simplifies the test process in the corrosion monitoring for the high-pressure natural gas pipeline.
Description
Technical field
The utility model patent relates to natural gas line corrosion monitoring technical field, particularly a kind of high pressure gas pipeline electric-resistivity method on-line corrosion monitoring instrument based on temperature compensation.Be that a kind of employing AC constant-current source encourages, finish the high pressure gas pipeline electric-resistivity method on-line corrosion monitoring instrument of temperature self-compensation.
Background technology
Along with the exploitation of Chinese large-sized oil gas field, particularly the exploitation successively of high pressure sulfur-bearing, carbonated rock gas is had higher requirement to the security in gas field.The corrosion prison detects concern and the attention that has more and more obtained larger hydrocarbon field manufacturing enterprise as an element task of corrosion protection.And resistance probe corrosion monitoring technology is by measuring the variation of hardware resistance value of corrosion process in processing medium, calculate the corrosion speed on-line monitoring of metal in processing medium, because resistance probe corrosion monitoring technology is applicable to and comprises gas phase, liquid phase, gas field such as solid phase and flow particles medium working environment and measurement are rapidly, the corrosion situation that can in time reflect equipment pipe, the rotten oil-gas pipeline of equipment pipe is carried out in real time, continuously, the networking remote monitoring, forecast pipeline or equipment corrosion erosion characteristics in the monitoring state all the time, be different from the advantage of other corrosion monitoring, often be used to degree assessment oil-gas pipeline corrosion damaged condition and pipeline expected life.
At present, electric-resistivity method monitoring both at home and abroad generally all is to carry out in low-pressure system, be pressure＜3MPa, and the temperature substantially constant of workspace, therefore all insensitive to thermoelectric force and contact electricity, and the high pressure gas pipeline road is a high-pressure system, i.e. pressure＞6.4MPa, the rock gas of monitoring is subjected to influence that environment and surface temperature change greatly from well head flows process in arriving at a station, requires higher to explosion-proof security, field environment and test data accuracy etc.United States Patent (USP) 5,446, and 369 (1995, Byrne, et al.) and United States Patent (USP) 6,556,027 (2003, all be Banks) about resistance probe corrosion detecting instrument.But the two does not all point out the influence of temperature to measurement result, do not adopt the auto thermal compensation technology yet, forming several commodity online resistance corrosion monitors application result in the corrosion monitoring of gas field according to above-mentioned technology shows: the reappearance of its measurement result and the stability of equipment are all less than solving, its reason is that the altitude temperature difference effect that the contact electricity of resistance probe inside is brought has greatly disturbed the corrosion monitoring result, rely on built-in reference resistance to carry out the compensation of temperature effect fully, be difficult to guarantee the corrosion monitoring accuracy of rock gas high pressure line and oil pipeline.Also there is the deficiency of monitoring result temperature influence in international magnetic resistance corrosion monitoring system simultaneously.
The utility model content
The purpose of this utility model is: a kind of high pressure gas pipeline electric-resistivity method on-line corrosion monitoring instrument is provided, utilize temperature compensation electric-resistivity method on-line corrosion monitoring instrument exploitation and eliminate junction potential, the thermoelectric force between the dissimilar metal in the resistance probe circuit, and the welding measuring error that effect caused, solve because the measuring resistance error due to the variation of ambient temperature by the exchange current circuit compensation, improve the measuring accuracy of corrosion rate.
The technical solution adopted in the utility model is: high pressure gas pipeline electric-resistivity method on-line corrosion monitoring instrument mainly comprises Resistance probe, alternating constant-current source, amplifier, converter, single-chip microcomputer, real-time clock, data-carrier store, lithium battery, voltage stabilizer and interface.It is characterized in that: single-chip microcomputer is arranged in Instrument shell, and single-chip microcomputer is connected with real-time clock, data-carrier store, interface and voltage stabilizer respectively, and voltage stabilizer is connected with lithium battery.Single-chip microcomputer connects two converters respectively, and two converters are connected with amplifier respectively.Two amplifiers have lead to connect Resistance probe respectively.Be connected with the alternating constant-current source on the Resistance probe.
Adopt high precision TPS71010 chip as the alternating constant-current source, the 3.6V lithium battery is the monitor power supply; Adopt two PGA203 programmable amplifiers to the terminal voltage of measured resistance Rx15 and reference resistance Rr14 (＜10mV) carry out preposition amplification; Sample simultaneously through AD770316bit ∑-Δ A/D converter then, its resolution can reach 1 μ V; Adopt high-speed low-power-consumption MCU single-chip microcomputer to carry out data acquisition and calculating, by Flash data-carrier store storage data, and announcement isolated form RS485 interface is sent to data in the host computer; This corrosion monitor adopts the DS1305 real-time clock, can wake up by self-timing (1～24 hour), and adopts controlled voltage stabilizer to prolong lithium battery serviceable life to greatest extent.
Described Resistance probe mainly is made up of cable socket, sealing screw thread and probing shell.Top at the sealing screw thread is connected with the cable socket, and the sealing filament portion of detaining is connected with the probing shell that insulating material is made.6 leads and a reference resistance Rr are arranged in probing shell, and reference resistance Rr two ends connect lead A and D respectively, are connected to the alternating constant-current source then.In the bottom of probing shell measured resistance Rx is arranged, measured resistance Rx two ends connect four of B in the lead and E, C and F etc. respectively, are connected to amplifier then.
The exchange current temperature compensation principle
The utility model proposes a kind of new measuring method based on the alternation waveform, promptly adopting AC signal to make the external excitation signal measures, by measuring the ratio of electric current in the electric potential difference of each node of resistance probe at out of phase angle, compensate the drift of node thermoelectric force, because node potential is the same with electrochmical power source, its electric potential difference is directive, therefore by changing the direction of current of excitation constant current source, can carry out full remuneration to node potential ξ.
When the exciting current direction is identical with clean node potential direction, then measure the combined potential in loop:
∑U(T)＝(V
IR+ξ)-(ξ-V
IR)＝2V
IR，
Thereby node potential ξ full remuneration is fallen.
The beneficial effects of the utility model: the utility model high pressure gas pipeline electric-resistivity method on-line corrosion monitoring instrument, the measuring accuracy of conventional, electric-resistance/magnetic resistance probe is improved 5～8 times, improved the measuring accuracy of equipment corrosion speed, adopt the high-speed low-power-consumption single-chip microcomputer as data acquisition, calculating and storage unit, reach fast, accurately measure the purpose of natural gas line corrosion rate.This patent is compared with existing electric-resistivity method on-line corrosion monitoring device, has following tangible advantage and characteristics:
1, high pressure gas pipeline electric-resistivity method on-line corrosion monitoring instrument adopts high-performance low-power-consumption 80C51F series monolithic and accurate AC constant-current source to encourage, built-in constant current circuit, the accurate Control current of energy is in 0～1A scope, the AC signal that constant current source produces makes by operational amplifier and is added on the probe, the two-way 16bit high-precision a/d converter of device interior and the measurement that the high-gain instrument amplifier is finished the weak voltage signal on the resistance probe simultaneously, by changing direction of current, carry out the automatic compensation of thermoelectric force, and according to the ratio of measurement voltage signal, be scaled the corrosion surplus and the corrosion rate of sensitive element, resistance corrosion monitoring instrument chip timing wake-up, the A/D data collection and analysis, the high capacity cell electric power system, the algorithm optimization of communications protocol optimization and datagraphic is optimized by software, and response speed is fast, the energy follow-on test, highly sensitive.
2, the resistance corrosion monitoring apparatus adopts alternating constant-current power supply and AV electric bridge mode to carry out the precision resister measurement, the main cause that has proposed to influence the corrosion rate measuring accuracy is not data-switching precision and the internal circuit noise from instrument internal, but poor from dissimilar metal junction potential in the sensor, this electric potential difference is the linear function of temperature.
3, reason and solution that the sensor measurement error exists have been proposed, measured the temperature coefficient of resistance probe, and because junction potential temperature that difference causes is floated problem, propose to adopt alternating constant-current power supply (current of commutation method) to carry out the compensation method of junction potential difference, improved the measuring accuracy of traditional resistor probe corrosion monitoring from hardware and software two aspects.
4, the resistance corrosion monitor in this patent is compared with weightless hanging slice method, and its response is fast, can follow-on test.Can effectively monitor the trickle trend that corrosion changes, the reliability height, data reappearance is good.
Description of drawings
Fig. 1. be the circuit design block diagram of high pressure gas pipeline electric-resistivity method on-line corrosion monitoring instrument.
Fig. 2 Resistance probe structural representation.
Fig. 3 is B in direct current, alternation are measured
X, r(t) with the variation of temperature curve
Among the figure, 1. Resistance probe, 2. alternating constant-current source, 3. amplifier, 4. converter, 5. single-chip microcomputer, 6. real-time clock, 7. data-carrier store, 8. lithium battery, 9. voltage stabilizer, 10. interface, 11. the cable socket, 12. sealing screw threads, 13. probing shells, 14. reference resistance Rr, 15. measured resistance Rx.
Embodiment
Embodiment 1:
Consult Fig. 1.The utility model high pressure gas pipeline electric-resistivity method on-line corrosion monitoring instrument mainly comprises Resistance probe 1, alternating constant-current source 2, amplifier 3, converter 4, single-chip microcomputer 5, real-time clock 6, data-carrier store 7, lithium battery 8, voltage stabilizer 9 and interface 10.
A single-chip microcomputer 5 is arranged in Instrument shell, and single-chip microcomputer 5 adopts tells low-power consumption 80C51F type MCU single-chip microcomputer 5.Single-chip microcomputer 5 is connected with a real-time clock 6, data storer 7, an interface 10 and a voltage stabilizer 9 respectively, and voltage stabilizer 9 is connected with lithium battery 8.What real-time clock 6 adopted is DS1305 real-time clock 6.What data-carrier store 7 adopted is Flash data-carrier store 7.Interface 10 is announcement isolated form RS485 interfaces 10.What lithium battery 8 adopted is the 3.6V lithium battery.
Single-chip microcomputer 5 also is connected with 4, two converters 4 of two converters respectively and is connected with amplifier 3 respectively.Two amplifiers 3 have lead to connect Resistance probe 1 respectively.Be connected with alternating constant-current source 2 on the Resistance probe 1.High precision TPS71010 chip is adopted in alternating constant-current source 2.Amplifier 3 adopts two PGA203 programmable amplifiers 3.Converter 4 is 16bit ∑-Δ A/D converters 4 of two AD7703.
Consult Fig. 2.Resistance probe 1 mainly is made up of cable socket 11, sealing screw thread 12 and probing shell 13.Sealing screw thread 12 is fixed on the high-pressure natural gas pipeline during installation.Top at sealing screw thread 12 is connected with cable socket 11, and sealing screw thread 12 bottoms are connected with the probing shell 13 that the insulating material resin is made.6 leads and a reference resistance Rr14 are arranged in probing shell 13, and reference resistance Rr14 two ends connect lead A and D respectively, are connected to alternating constant-current source 2 then.In the bottom of probing shell 13 measured resistance Rx15 is arranged, measured resistance Rx15 two ends connect four of B in the lead and E, C and F etc. respectively, are connected to amplifier 3 then.
Reference resistance Rr14 in the Resistance probe 1 and the resistance value of measured resistance Rx15 are less, generally below 10m Ω, therefore big electric current AC constant-current source 2 is carried out signal excitation, adopt high-precision front end difference (instrument) signal amplifier of two-way and data transmitter simultaneously, surveying instrument uses high-capacity lithium battery 8 and high precision alternation constant pressure source 2,5 of high speed MCU processing units adopt power-down mode to replace sleep pattern, guarantee the carrying out of regularly measuring.Adopted real-time clock 6 among the design, writing down real-time time accurately, and timing wake-up single-chip microcomputer 5 (MCU), recover surveying work.For analog to digital converter 4, select two-way 16bit ∑-Δ converter A/D converter 3 high sampling precisions for use, result of calculation is kept in the non-loss flash storer 7.This equipment has the RS485 serial interface 10 of an isolation, is responsible for the communication between equipment and remote computer.
Consult Fig. 2.In fact the key component of Resistance probe 1 is exactly an one metal wire, a part wiry is sealed in resin or the glass ceramics, isolate with external environment, resistance R r14 for referencial use, a part is directly exposed in the corrosion environment as corrosion monitoring measured resistance Rx15 in addition, as measuring sensor, the two is in the same temperature environment.Be connected by six core shielded cables between resistance corrosion detector and the Resistance probe 1, Resistance probe 1 one ends are fixedlyed connected with tested pipeline by NPT sealing screw thread 12, sealingly secure under the stable and high pressure of assurance test mode, Resistance probe 1 other end is measured resistance Rx15.Direct and the tested corrosion environment of measured resistance Rx15 contacts.
The influence of temperature variation to the precision resistance measurement result described among Fig. 3, the visible samples classic method, variation of temperature is very big to resistance measurement influence, curve description forward U
Bd(a-f) and oppositely U
Bd(f-a) temperature variant linear fit, and the temperature variant linear fit curve of the ratio of forward and reverse electromotive force.The exchange current method compensate the drift of node thermoelectric force by the commutation measurement of electric current by realizing in this patent.Because the resistance ratio B of forward and reverse measurement
X, r(t) temperature coefficient is opposite, the therefore absolute value of forward and reverse measurement result and not changing in theory with temperature, thus having reached the purpose of compensation node potential, realization is to the automatic compensation of thermoelectric force.Adopt the measured deviation that is caused by temperature after this patent method only to be 1/8 of classic method, exchange current is measured can eliminate junction potential, reduces the contact electricity that is caused by temperature fluctuation and changes, and has improved the corrosion rate measuring accuracy.
Claims (3)
1, a kind of high pressure gas pipeline electric-resistivity method on-line corrosion monitoring instrument, mainly comprise Resistance probe (1), alternating constant-current source (2), amplifier (3), converter (4), single-chip microcomputer (5), real-time clock (6), data-carrier store (7), lithium battery (8), voltage stabilizer (9) and interface (10), it is characterized in that: single-chip microcomputer (5) is arranged in Instrument shell, single-chip microcomputer (5) is connected with real-time clock (6) respectively, data-carrier store (7), interface (10) and voltage stabilizer (9), voltage stabilizer (9) is connected with lithium battery (8), single-chip microcomputer (5) connects two converters (4) respectively, two converters (4) are connected with amplifier (3) respectively, two amplifiers (3) have lead to connect Resistance probe (1) respectively, are connected with alternating constant-current source (2) on the Resistance probe (1).
2, high pressure gas pipeline electric-resistivity method on-line corrosion monitoring instrument according to claim 1 is characterized in that: high precision TPS71010 chip is adopted in described alternating constant-current source (2); Lithium battery (8) is 3.6V; Described amplifier (3) adopts two PGA203 programmable amplifiers (3); Described converter (4) is AD7703 16bit ∑-Δ A/D converter (4); Described single-chip microcomputer (5) adopts high-speed low-power-consumption 80C51F type MCU single-chip microcomputer (5); Described data-carrier store (7) is Flash data-carrier store (7); Described interface (10) is an announcement isolated form RS485 interface (10); What real-time clock (6) adopted is DS1305 real-time clock (6).
3, high pressure gas pipeline electric-resistivity method on-line corrosion monitoring instrument according to claim 1, it is characterized in that: described Resistance probe (1) is mainly by cable socket (11), sealing screw thread (12) and probing shell (13) are formed, top at sealing screw thread (12) is connected with cable socket (11), sealing screw thread (12) bottom is connected with the probing shell (13) that insulating material is made, a six conductors and a reference resistance Rr (14) are arranged in probing shell (13), reference resistance Rr (14) two ends connect lead A and lead D respectively, be connected to alternating constant-current source (2) then, in the bottom of probing shell (13) measured resistance Rx (15) is arranged, measured resistance Rx (15) two ends connect lead B and the lead E in the six conductors respectively, lead C and lead F are connected to amplifier (3) then.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008201086349U CN201218804Y (en) | 2008-06-04 | 2008-06-04 | Resistor method on-line corrosion monitoring instrument for high pressure gas pipeline |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008201086349U CN201218804Y (en) | 2008-06-04 | 2008-06-04 | Resistor method on-line corrosion monitoring instrument for high pressure gas pipeline |
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| CN201218804Y true CN201218804Y (en) | 2009-04-08 |
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102768228A (en) * | 2011-03-16 | 2012-11-07 | 深圳格鲁森科技有限公司 | Online pipeline corrosion measuring method |
| CN102998341A (en) * | 2012-10-30 | 2013-03-27 | 交通运输部公路科学研究所 | Device and method for testing corrosion degree of steel bundle |
| CN104155235A (en) * | 2014-09-10 | 2014-11-19 | 四川省科学城海天实业总公司 | Atmospheric corrosion rate online monitoring sensor |
| CN104458561A (en) * | 2014-12-02 | 2015-03-25 | 武汉科思特仪器有限公司 | Compound probe, device and method for monitoring corrosion of down-hole string on line and in real time |
| CN105181568A (en) * | 2015-09-28 | 2015-12-23 | 武汉科思特仪器有限公司 | Device for monitoring corrosion of oil and gas field gathering pipelines and corrosion inhibitor filling system |
| CN105988015A (en) * | 2016-06-06 | 2016-10-05 | 上海理工大学 | Oil-line corrosion and gas monitoring system of transformer |
| CN107725027A (en) * | 2017-09-25 | 2018-02-23 | 中海油常州涂料化工研究院有限公司 | A kind of online downhole well corrosion monitoring system |
| CN108996062A (en) * | 2018-06-28 | 2018-12-14 | 江苏瑞能防腐设备有限公司 | A kind of anti-corrosion storage tank system being provided with on-line monitoring prior-warning device |
| US20230119818A1 (en) * | 2021-10-14 | 2023-04-20 | Saudi Arabian Oil Company | Thermoelectric polymer system for corrosion monitoring |
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- 2008-06-04 CN CNU2008201086349U patent/CN201218804Y/en not_active Expired - Lifetime
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102768228B (en) * | 2011-03-16 | 2014-10-29 | 深圳格鲁森科技有限公司 | Online pipeline corrosion measuring method |
| CN102768228A (en) * | 2011-03-16 | 2012-11-07 | 深圳格鲁森科技有限公司 | Online pipeline corrosion measuring method |
| CN102998341A (en) * | 2012-10-30 | 2013-03-27 | 交通运输部公路科学研究所 | Device and method for testing corrosion degree of steel bundle |
| CN102998341B (en) * | 2012-10-30 | 2014-08-20 | 交通运输部公路科学研究所 | Device and method for testing corrosion degree of steel bundle |
| CN104155235A (en) * | 2014-09-10 | 2014-11-19 | 四川省科学城海天实业总公司 | Atmospheric corrosion rate online monitoring sensor |
| CN104458561B (en) * | 2014-12-02 | 2017-07-18 | 武汉科思特仪器股份有限公司 | Corrode the device and method of on-line real time monitoring for down-hole string |
| CN104458561A (en) * | 2014-12-02 | 2015-03-25 | 武汉科思特仪器有限公司 | Compound probe, device and method for monitoring corrosion of down-hole string on line and in real time |
| CN105181568A (en) * | 2015-09-28 | 2015-12-23 | 武汉科思特仪器有限公司 | Device for monitoring corrosion of oil and gas field gathering pipelines and corrosion inhibitor filling system |
| CN105988015A (en) * | 2016-06-06 | 2016-10-05 | 上海理工大学 | Oil-line corrosion and gas monitoring system of transformer |
| CN107725027A (en) * | 2017-09-25 | 2018-02-23 | 中海油常州涂料化工研究院有限公司 | A kind of online downhole well corrosion monitoring system |
| CN108996062A (en) * | 2018-06-28 | 2018-12-14 | 江苏瑞能防腐设备有限公司 | A kind of anti-corrosion storage tank system being provided with on-line monitoring prior-warning device |
| CN108996062B (en) * | 2018-06-28 | 2024-06-07 | 江苏瑞能氟材料科技有限公司 | Anti-corrosion storage tank system provided with online monitoring and early warning device |
| US20230119818A1 (en) * | 2021-10-14 | 2023-04-20 | Saudi Arabian Oil Company | Thermoelectric polymer system for corrosion monitoring |
| US11815444B2 (en) * | 2021-10-14 | 2023-11-14 | Saudi Arabian Oil Company | Thermoelectric polymer system for corrosion monitoring |
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