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In order to meet the standard management of coal pile in coal yard and provide a kind of digital display thermometer for measuring the temperature inside coal pile, a kind of thermometer for measuring the temperature inside coal pile is designed and manufactured. The coal pile thermometer is composed of two parts: the injection type of the coal pile thermometer and the special temperature probe for the coal pile. The coal pile thermometer can be used to measure the internal temperature of the coal pile quickly and conveniently on site and prevent the spontaneous combustion of the coal pile effectively.
It is a special coal pile temperature measuring instrument for measuring internal temperature of coal pile. By measuring the internal temperature of the coal pile with the coal pile thermometer, the heat condition in the coal pile can be known in time, and measures can be taken as soon as possible to eliminate the occurrence of spontaneous combustion of the coal pile and prevent the serious consequences of spontaneous combustion of the coal pile in the coal yard. Welcome to use coal pile thermometers. The coal pile thermometer is simple to operate. A hand-held coal pile thermometer, a hand-held coal pile temperature probe, the coal pile temperature probe inserted into the coal pile, the coal pile thermometer is that can read the temperature.
It is composed of two parts: coal pile thermometer and needle pile temperature probe. Needle coal pile temperature measurement probe, the head is needle structure, and has a strong steel, inserted into the coal pile inside not bending, not broken, can smoothly measure the temperature of the coal pile. Temperature probe conventional length of 1 m, 1.5 m, 2 m, 3 m. The measuring end of the temperature probe is at the top, in other words, the temperature measured is the temperature at which the temperature probe is inserted deep into the coal pile.
Transformer capacity and empty load tester can measure the capacity of various distribution transformers, passive measurement, and can measure various types of transformer no-load current, no-load loss, short-circuit voltage, short-circuit loss, zero sequence impedance. Also can be automatically waveform distortion correction, temperature correction, voltage correction (no-load test under non-rated voltage), current correction (short circuit test under non-rated current condition), the operator only according to the transformer type input calibration index instrument, can automatically calculate the results after correction.
Allow external voltage, current transformer extended range measurement can be measured arbitrary parameters of the tested products. It is very suitable for units without short circuit test conditions of slightly larger capacity transformers. Voltage loop width limit: the voltage can be measured to 750V, and the accuracy can be guaranteed without switching gears. No damage to the instrument itself due to the wrong selection of voltage range. Users can test the data at any time through the micro printer to print out the results.
Large screen, high brightness LCD display, full Chinese menu and operation hints to achieve friendly man-machine dialogue, touch the key to make the operation more convenient, wide temperature LCD with brightness adjustment, can adapt to winter and summer seasons. Do not touch the metal part of the test line during the measurement to avoid being injured by electricity. The test wiring shall be carried out under the condition of grounding of the tested line to prevent electric shock by induced voltage. All short circuits, grounding and leads shall have sufficient cross sections and shall be securely connected. The test organization should be strict and the communication should be smooth to ensure the smooth progress of the test work.
Transformer oils of early fault characteristics of the gas is carbon monoxide and hydrogen, which is mainly the organic insulation materials and insulating oil inside the transformer, along with the increase of the transformer running time, and under the long-term effects of heat and electricity produced by aging, decomposition, and together they produce gas and carbon dioxide and hydrocarbon gases, are most of these gases dissolved in transformer oil.
The work principle of transformer on-line monitoring device is characteristic of transformer oil gas through attached directly to the transformer body sensor inside the osmosis membrane selectively into the gas detector, and with the sensor inside the fuel cell and oxygen in the air react to produce a reaction rate is proportional to the output signal, After the rectifier amplifies the output signal and temperature compensation signal, the device display in the form of volume fraction value μL/L to the technical personnel.
The sensor is a passive component, no rotating part, and does not need any reagents or other materials. The fuel it needs is characteristic gas. The sensitivity of on-line partial discharge monitoring of transformer is generally above 1000 pC, which is higher than the value specified in off-line transformer factory test. Therefore, the existing system mainly analyzes the transformer insulation status according to the long-term development trend of PD, rather than completely according to a single measurement value. In addition, partial discharge ellipse, two-dimensional spectrum and three-dimensional spectrum can be used to analyze the types of partial discharge.
In addition, the transformer core grounding current can be monitored online to judge whether the transformer core has multi-point grounding fault. The status of on-load voltage regulating switch of transformer and the dielectric loss of bushing are monitored on line, but the moisture in transformer oil, the temperature distribution of winding (determining the temperature of winding hot spot) and the aging parameters of paper insulation (such as furfural) cannot be monitored on line.
There are two ways of transformer core grounding, namely direct grounding and casing lead grounding. Direct grounding involves putting one end of the tinned copper sheet between the yoke laminators. When the yoke is pressed, it becomes a dead end, and the other end is bolted to the yoke clamps, because normally the yoke clamps are in direct contact with the fuel tank, which is grounded. In the case of hanging cover (hanging core), it can be disassembled at any time to measure the insulation of the core.
The lead grounding of bushing is required to measure the medium loss Angle of coil for large power transformer with electricity. The iron yoke clamp is insulated from the oil tank. After connecting the iron core to the yoke clamp with copper sheet, the lead is led out from the small insulating bushing installed at the bottom of the oil tank and then grounded outside the oil tank. At this point, the core part of the power transformer is insulated from the tank.
Transformer core grounding reason: when the power transformer is in normal operation, the iron core must have a little reliable grounding. If there is no grounding, the suspension voltage of the iron core to the ground will cause the intermittent breakdown and discharge of the iron core to the ground, and the possibility of forming the suspension potential of the iron core is eliminated after the iron core is grounded. However, when the core is grounded at more than two points, the uneven potential between the cores will form a circulation between the ground points, and cause the multi-point grounding heating fault of the core.
The ground fault of the iron core of the transformer will cause the local overheating of the iron core. In serious cases, the local temperature rise of the iron core will increase, light gas action, and even the trip accident of heavy gas action will be caused. The short-circuit fault between the iron chips caused by the burnt partial iron core increases the iron loss and seriously affects the performance and normal operation of the transformer, so that it is necessary to replace the iron core silicon steel sheet for repair. So transformers do not allow multi-point grounding and only one point grounding.
The detection of insulating oleic acid value is a routine inspection item for electric power system and oil-filled electrical equipment in industrial and mining enterprises. Oleic acid value tester adopts the principle of neutralization method, under normal temperature state, microcomputer control automatically complete liquid, stirring, titration and end point judgment. Adopt touch type LCD screen to select all working parameters, man-machine dialogue interface is simple and friendly, easy to operate, the average analysis cycle of oil sample is about 2 minutes. Can display up to 35 groups of measurement results, and can print out a number of parameters related to the measurement. The purchase of "insulating oleic acid value tester" should pay attention to several points:
1. Reagent bottle contains extraction liquid and neutralization liquid. The extracted liquid is stored in glass containers to ensure no plastic additives. The neutralization liquid is stored in polyethylene plastic bottle, which completely avoids the possibility of reaction between potash and glass. Instrument with neutralization liquid balance gas solid purification device, completely avoid carbon dioxide and water vapor on the concentration of neutralization liquid, more will not happen to high concentration of caustic potash or caustic soda purification solution as titration standard solution used accident.
2, microcomputer control automatically complete liquid, stirring, titration and end point judgment. Adopt touch type LCD screen to select all working parameters, man-machine dialogue interface is simple and friendly, easy to operate, the average analysis cycle of oil sample is about 2 minutes. Can display up to 35 groups of measurement results, and can print out a number of parameters related to the measurement.
3. The level of the oleic acid value tester and the accuracy of the instrument are two different concepts, and the instrument level is not completely consistent with its accuracy. Acid value is determined by the level of its indicator (referred to as meter) indexing value (resolution or small display value), such as: indexing for 0.1pH instrument called 0.1 instrument; Instruments with a small display value of 0.001pH are called 0.001 class instruments and so on.
And the accuracy of the oleic acid value tester is the comprehensive error of the standard solution of the meter and the electrode, which is not only related to the meter, but also related to the glass electrode and the reference electrode. Starting from the actual use requirements, the meter's index value is 0.1 ~ 0.001pH, if necessary, according to the current level of science and technology, can make a more precise meter. However, due to structural and manufacturing reasons, the performance of common electrodes can not reach a completely ideal level.
1, input power supply: connect the grounding of the oil pressure tester, insert 220V AC power supply, check the power supply is correct. Adjust the distance between the two electrodes of the oil cup to 2.5mm, rotate the feeler rod at one end of the oil cup shaft rod counterclockwise, adjust the other end electrode in the center position, tighten the screw locking the shaft rod, take the feeler rod between the two electrodes close the two electrodes, lock the screw, remove the feeler rod, rotate clockwise in the original shaft rod.
2. Clean the oil cup, place a clean magnetic oscillator in the oil cup, fill it with the prepared oil sample, remove the high pressure cover, place the oil cup between the two high pressure columns in the high pressure chamber, and place the high pressure cover on the cover smoothly and press the switch. Then it is the scheduled setting of the insulating oil pressure tester. Press the "test value" button when testing, stirring, standing, boosting and printing functions will be in the order of fixed values. Press the "stop" button in the process of boosting, it will stop boosting, and the value on the digital display is the high voltage output value of the high voltage terminal at this time.
After 3, booster sample breakdown, acoustic remind continuous sound "di" is a short 20 seconds, two "di" after two short sound, the sixth "di", a long a short sound, the seventh "di" is a long sound 2 short, average stay after the show "di" non-stop ringing for 20 seconds, if it's not acoustic warning, click on the voice control key to enter relating to remind, optical indicator, The number of flashes is the same as the number of "beep" sound. Pressing the voice control button again is invalid. Keep the light control unchanged, and the voice control will be effective when the power is turned on again.
4. After the test, if you want to view the data again, press "Display" and "print". These two keys belong to repeated use. When you press "Print", the voltage value will not be printed repeatedly. When the "reset" button is pressed, the word "OCPU" displayed in English means the initial waiting state after the reset is in place, referred to as the initial state or OCPU state. If the "Reset" button is pressed in the test boost process, it will not enter the initial state. It is the same as the situation in the breakdown of oil sample. If continuously press the "reset" key, it will be confirmed as "reset" and enter the initial state.
5, start waiting: when the power is ON, the machine enters the self-checking state, the printer responds with the indicator light ON, and the display screen shows the words OCPU. If the voltage regulator is not at zero, the display word DIJJ indicates the reset process. The drop indicator light is ON, and the initial OCPU waiting state is displayed after falling to zero.
6. Click the "test value" key and start to run according to the preset value; The stirring indicator light is on and the magnetic oscillator rotates rapidly. One di digit on the display screen shows the number of DI times, and the last three digits show the stirring time. Mixer mixing, oscillator stop light, a quiet place indicator to let stand, after lights out, switching, pressure indicator, and into the display synchronous booster, the display screen after three digital display for voltage (00.0 KV) after being sample breakdown, boosting the power automatic brake, a stop display 5 seconds, the printer to print time, voltage value.
7. Under the voltage regulator, the drop indicator light is on, and the mixing indicator light is on DI second test begins. At the same time, the printing and display screen display breakdown voltage, display secondary value flashing, and voice control reminder; After the voltage regulator returns to zero, the drop indicator is off, the display stops flashing, and the voice control disappears. Then di is tested twice. After all test times are run, the screen displays the average of the total times, such as a24.3kV for only one test, f24.3kV for six tests; Then print the average voltage, the oil sample test is completed, at this time can be repeated display, print, press the reset button, all data disappear. After taking out the oil sample in OPCU state, the new oil sample can be replaced and tested again. After testing, the power supply is turned OFF in the OFF position under reset state.
Dc resistance tester is a convenient and effective test to inspect the winding insulation and current loop connection of electrical equipment. By measuring the DC resistance, you can check the welding or connection quality of the lead, whether the winding is short or open between turns, and whether the contact of the tap switch is good.
According to "GB26860-2001 Power safety work regulations" provisions, transformer in the handover, overhaul, minor repair, change tap location fault and preventive test, dc resistance test must be carried out. In the past, single-arm and double-arm Bridges were used to measure the main resistance. The measuring current of this kind of bridge is milliampere level, and the measuring process is time-consuming and the accuracy is low. The appearance of the current resistance tester shortens the measuring time and effectively reduces the workload of the tester.
Dc resistance tester in addition to superior performance, good reliability, easy to use and other characteristics, can also be used as 1μV~2V voltage measurement, as well as testing small motor, transformer winding resistance, widely used in laboratories, mining sites and other places, is an ideal DC resistance measurement instrument.
Dc resistance tester adopts typical four-wire measurement method. In order to improve the accuracy of measuring resistance (especially low resistance). Program-controlled constant current source, program-controlled preamplifier and A/D converter constitute the main body of the measuring circuit. The central control unit applies a constant and high-precision current to the external load to be tested by controlling the constant current source. Then, the obtained data (including test voltage, current test current, etc.) are processed to obtain the actual resistance value.
The prerequisite of transformer on-line monitoring is network with computer. Use IT technology to obtain transformer status information through standardized software or browser. Through the system analysis, calculation of measured data, combined with expert system to do comprehensive intelligent diagnosis. The technical superiority of online monitoring is mainly reflected in its own self-checking function and the ability of comprehensive fault judgment after combination.
Because the purpose of online monitoring is to prolong the life of high-voltage equipment, improve the power supply quality and economic benefit of the power department, the cost of online monitoring device should not be too high. According to the statistical analysis of the domestic power department, if the transformer accident rate is set at 0.5 ~ 1%, then the cost of online monitoring should not exceed this range.
The main feature of transformer on-line monitoring is to judge transformer operation status by continuously monitoring the variation trend of transformer parameters for a period of time. On-line monitoring can capture the precursor information of non-instantaneous failure. Its outstanding feature is that it can be monitored in real time during operation. This is the technical advantage of online monitoring. Although there are great limitations in the prediction of sudden faults in transformers based on the dynamic information captured by on-line monitoring, it is a means of modern state maintenance.
It has very important practical guiding significance for making and arranging maintenance plan and scheme in the next step. The monitoring instrument used in mutual monitoring (such as sensor, etc.) has high reliability, installed on the transformer does not need to be maintained, with high self-check function. Once the monitor itself has problems, it can automatically send out sound and light alarm. Therefore, all kinds of errors and inaccuracies caused by human beings in conventional detection methods are eliminated. The period of online monitoring is set for man and can range from a few hours to several years.
Transformer capacity tester is a common high voltage electrical testing equipment, mainly used to measure the DC resistance of power transformers. Transformer DC resistance tester is a common high voltage electrical testing equipment, mainly used to measure the DC resistance of power transformers. It has also been widely used in power industry, but many people do not know about its measurement and discharge work. For transformer DC resistance tester measurement, after connecting the test line, turn off the power switch, turn on the power indicator, press the "start and stop button".
Select the range of resistance range according to the measured value, press the range switch, the range indicator will light up, the stable value displayed on the LCD screen is the measured resistance value. When reading the values, note the units in the selected range and measure large inductance samples such as power transformers and other test circuits other than coils. To avoid electromagnetic interference, it is not necessary to measure short circuits. Transformer DC resistance tester discharge, test should be directly cut off the main power supply.
If the power supply should not be cut off immediately after operation in a perception test, the instrument should have a continuous discharge process, usually at least 20 seconds. Otherwise the inductance of the back potential will be a crisis of personal safety, in the power industry has also been widely used. Transformer DC resistance tester for measurement, after connecting the test line, turn off the power switch, turn on the power indicator, press the "start and stop button". Select the range of resistance range according to the measured value, press the range switch, the range indicator will light up, the stable value displayed on the LCD screen is the measured resistance value.
When reading the values, note the units in the selected range and measure large inductance samples such as power transformers and other test circuits other than coils. To avoid electromagnetic interference, it is not necessary to measure short circuits. When discharging, the main power supply should be cut off directly after testing. If the power supply should not be cut off immediately after operation in a perception test, the instrument should have a continuous discharge process, usually at least 20 seconds. Otherwise, the back potential of the inductor will be a personal crisis.
Transformer capacity and loss measuring instrument has small volume, light weight, high measurement accuracy, good stability and other features, also USES the large screen LCD display window, menu action figure form with Chinese characters suggest that set many parameters in a screen display interface, the man-machine dialogue friendly interface, easy operation, and the advantages of easy to learn, greatly improving the work efficiency, It is the product of various power users and quality supervision departments.
Transformer capacity tester is composed of two parts, the host is the core of the instrument, all the electrical parts are inside the host, the host box adopts high strength imported waterproof injection molding case, durable, accessories box is used to place test wires and tools. Before testing, make sure that the parameters set are correct.
The test wiring of transformer capacity and loss tester must be carried out under the condition of grounding of the tested line to prevent electric shock by induced voltage. All short circuits, grounding and leads shall have sufficient cross sections and shall be securely connected. The test organization should be strict and the communication should be smooth to ensure the smooth progress of the test work. Use an electrical outlet with a ground cable.
During the short circuit test, if the high voltage or medium voltage side outlet bushing is equipped with annular current transformer, the secondary current transformer must be short-circuited before the test. During the short circuit test, the short connection of the non-pressurized side must be good, otherwise it will affect the test result. Cannot operate under voltage and current overlimits. Do not touch the metal part of the test line during the measurement to avoid being injured. Measuring wiring must be operated strictly according to the instructions, otherwise the consequences shall be borne by you.