Gas production rate measuring device for arc fault in insulating oil

Abstract

The utility model discloses a gas production rate measuring device for an arc fault in insulating oil, which belongs to the technical field of power transmission and transformation of an electric power system and comprises a discharge cavity for containing the insulating oil and nitrogen and an electrode pair arranged in the discharge cavity, the top of the discharge cavity is communicated with an oil conservator, and a detection device penetrating out of the oil conservator is arranged in the oil conservator. An oil hole is formed in the bottom of the discharging cavity. According to the utility model, the discharge cavity is communicated with the oil conservator, and the digital static thermometer and the pressure gauge are adopted to measure the gas pressure and temperature change of the oil conservator before and after an arc fault so as to calculate the gas production rate; by opening a connecting pipeline valve before and after an experiment, the gas volume cardinal number of gas production calculation is increased under the condition that the volume of buffer gas in a discharge cavity is small in the arc discharge process, so that the measurement error of the gas production is reduced; and the internal pressure of the discharge cavity is greatly reduced during measurement, and the calculation error of the gas production rate caused by the deformation of the discharge cavity can be ignored, so that the calculation precision is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of power transmission and transformation of electric power systems, and particularly relates to a gas production measurement device for arc faults in insulating oil. Background Art

[0002] Power transformers are crucial to the safe and stable operation of power systems. When an arc discharge occurs inside an oil-immersed power transformer, the arc vaporizes and cracks the transformer oil, producing bubbles that envelop the arc. As the arc's deposited energy accumulates on a millisecond scale, the bubbles rapidly expand. Due to the weak compressibility of the transformer oil, overpressure is generated inside the transformer. High-energy arc faults can even cause the casing to rupture. The contact of high-temperature cracked gas and oil mist with air can trigger a secondary explosion, further exacerbating the hazards of arc faults. Arc-induced bubbles are the primary pressure source of arc faults, and the gas production is an important basis for studying arc fault pressure, which is of great significance for studying arc fault pressure characteristics.

[0003] There are currently two main ways to measure the gas production of insulating oil:

[0004] A diaphragm pressure relief valve is installed on the top of the discharge chamber, and the output port of the pressure relief valve is connected to the gas tank. The gas tank is evacuated before the experiment. During arc discharge, the interior of the discharge chamber is in an overpressure environment. When the pressure threshold of the pressure relief valve is reached, the diaphragm pressure relief valve ruptures, and the generated gas enters the gas tank. The gas production of the arc discharge is calculated by measuring the pressure and temperature of the gas tank before and after the experiment.

[0005] Another method involves retaining a trace amount of gas within the discharge chamber and calculating the arc discharge gas production by measuring the gas pressure and temperature before and after the experiment. The first method is more complex and expensive, while the second method is simpler and less expensive. However, when the arc discharge energy is high, the gas production increases. This causes significant deformation of the discharge chamber, which can significantly change the gas volume within the chamber, leading to significant errors in the gas production calculation. Furthermore, the discharge chamber has a relatively large cross-sectional area, so even small changes in the insulating oil level can cause significant errors in the gas production measurement. Utility Model Content

[0006] The purpose of the utility model is to provide a gas production measurement device for arc faults in insulating oil, which solves the technical problems of large discharge cavity deformation and large calculation error of gas production caused by buffer gas volume error during existing insulating oil gas production measurement.

[0007] The technical solution adopted by the utility model is a gas production measuring device for an arc fault in insulating oil, comprising a discharge cavity for containing insulating oil and nitrogen and an electrode pair arranged in the discharge cavity, the top of the discharge cavity is connected to an oil pillow, a detection device passing through the oil pillow is provided in the oil pillow, and an oil hole is opened at the bottom of the discharge cavity.

[0008] The utility model is also characterized in that:

[0009] The discharge cavity and the oil pillow are connected through a connecting pipe, and a valve b is provided on the connecting pipe.

[0010] The discharge chamber comprises a main body and a cover plate which are detachably sealed and connected, and a connecting pipe passes through the cover plate and is communicated with the interior of the main body.

[0011] The electrode pair comprises two electrodes whose ends extend out of the discharge cavity and are connected to a power source, and a copper wire is connected between the two electrodes.

[0012] The oil hole at the bottom of the discharge cavity is connected with a valve a, and the valve a is connected with an insulating oil tank.

[0013] The bottom of the oil pillow is connected with valve c, valve d and valve e respectively. Valve c is connected with a vacuum pump, valve d is connected with a nitrogen source, and valve e is connected with a gas collection device.

[0014] The detection device includes a digital static thermometer and a digital static pressure gauge that extend into the oil pillow.

[0015] An oil leakage pool is provided at the bottom of the discharge cavity.

[0016] The beneficial effects of the utility model are:

[0017] The utility model calculates the gas production by connecting the discharge cavity and the oil pillow and measuring the gas pressure and temperature changes of the oil pillow before and after the arc fault using a digital static thermometer and a digital static pressure gauge.

[0018] By opening the connecting pipe valve before the experiment, the volume of buffer gas in the discharge chamber is kept small during the arc discharge process, which increases the gas volume base for calculating the gas production and greatly reduces the measurement error of the gas production. By opening the connecting pipe valve after the experiment, the pressure inside the discharge chamber is greatly reduced, and the calculation error of the gas production caused by the deformation of the discharge chamber can be ignored, thereby improving the calculation accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The utility model is a structural schematic diagram of a gas production measuring device for arc fault in insulating oil.

[0020] In the figure, 1. discharge chamber, 2. oil pillow, 3. connecting pipe, 4. oil leakage pool, 5. insulating oil, 6. nitrogen, 7. electrode, 8. copper wire, 9. valve a, 10. valve b, 11. valve c, 12. valve d, 13. valve e, 14. digital static thermometer, 15. digital static pressure gauge. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0022] Example 1

[0023] like Figure 1 As shown, the gas production measuring device for arc fault in insulating oil disclosed in this embodiment includes a discharge chamber 1 for containing insulating oil 5 and nitrogen and an electrode pair arranged in the discharge chamber 1, the top of the discharge chamber 1 is connected to an oil pillow 2, and a detection device passing through the oil pillow 2 is provided in the oil pillow 2, and an oil hole is opened at the bottom of the discharge chamber 1.

[0024] In this embodiment, the discharge cavity 1 is used to contain insulating oil and nitrogen, the electrode pair is used to discharge in the discharge cavity 1, the detection device is used to detect the temperature and pressure inside the oil pillow 2, and the oil hole is used to input insulating oil into the discharge cavity 1 or output the insulating oil in the discharge cavity 1.

[0025] Example 2

[0026] The gas production measurement device for an arc fault in insulating oil disclosed in this embodiment includes a discharge chamber 1 for containing insulating oil 5 and nitrogen and an electrode pair arranged in the discharge chamber 1. The top of the discharge chamber 1 is connected to an oil pillow 2, and a detection device is provided in the oil pillow 2 and passes through the oil pillow 2. An oil hole is opened at the bottom of the discharge chamber 1.

[0027] The oil hole at the bottom of the discharge chamber 1 is connected to a valve a9, which is connected to the insulating oil tank. An oil leak sump 4 is located at the bottom of the discharge chamber 1. The discharge chamber 1 and the oil pillow 2 are connected via a connecting pipe 3, which is equipped with a valve b10 for connecting or disconnecting the discharge chamber 1 and the oil pillow 2.

[0028] In this embodiment, the discharge chamber 1 is used to hold insulating oil and nitrogen. The electrode pair is used to discharge within the discharge chamber 1. The detection device is used to detect the temperature and pressure within the oil pillow 2. The oil hole is used to input and output insulating oil into and from the discharge chamber 1. Valve a9 installed at the bottom of the discharge chamber 1 is used to control the injection and discharge of insulating oil 5 within the discharge chamber 1.

[0029] Valve b10 is used to connect or isolate the discharge chamber 1 and the oil pillow 2. Since the cross-sectional area of ​​the chamber used in the oil arc experiment is generally large, and the volume of the buffer gas in the discharge chamber is relatively small, a small change in the liquid level will result in a large change in the gas volume. By opening valve b10 on the connecting pipe 3 before the experiment, the buffer gas volume in the discharge chamber 1 is kept small during the arc discharge process. This increases the gas volume base for calculating the gas production, that is, V in Formula 1, thereby greatly reducing the measurement error of the gas production.

[0030] After the oil arc experiment, a large amount of gas is generated, and the internal pressure of the discharge chamber 1 is high. The discharge chamber 1 will be deformed to a certain extent, resulting in a change in the gas phase volume inside the discharge chamber 1, which in turn affects the calculation of the gas production. After the experiment, the valve b10 on the connecting pipe 3 is opened, and the internal pressure of the discharge chamber 1 is greatly reduced. The error in the calculation of the gas production caused by the deformation of the discharge chamber 1 can be ignored, thereby improving the calculation accuracy.

[0031] Example 3

[0032] The gas production measurement device for an arc fault in insulating oil disclosed in this embodiment includes a discharge chamber 1 for containing insulating oil 5 and nitrogen and an electrode pair arranged in the discharge chamber 1. The top of the discharge chamber 1 is connected to an oil pillow 2, and a detection device is provided in the oil pillow 2 and passes through the oil pillow 2. An oil hole is opened at the bottom of the discharge chamber 1.

[0033] The electrode pair includes two electrodes 7 whose ends extend out of the discharge chamber 1 and are connected to a power source, and a copper wire 8 is connected between the two electrodes 7 .

[0034] In this embodiment, the discharge chamber 1 is used to contain insulating oil and nitrogen. The electrode pair is used to generate discharge within the discharge chamber 1. The detection device is used to detect the temperature and pressure within the oil pillow 2. The oil hole is used to input and output insulating oil into the discharge chamber 1. Copper wire 8 is used to generate an arc.

[0035] Example 4

[0036] The gas production measurement device for an arc fault in insulating oil disclosed in this embodiment includes a discharge chamber 1 for containing insulating oil 5 and nitrogen and an electrode pair arranged in the discharge chamber 1. The top of the discharge chamber 1 is connected to an oil pillow 2, and a detection device is provided in the oil pillow 2 and passes through the oil pillow 2. An oil hole is opened at the bottom of the discharge chamber 1.

[0037] The bottom of the oil pillow 2 is connected with valve c11, valve d12 and valve e13 respectively. Valve c11 is connected with a vacuum pump, valve d12 is connected with a nitrogen source, and valve e13 is connected with a gas collection device.

[0038] In this embodiment, the discharge cavity 1 is used to contain insulating oil and nitrogen, the electrode pair is used to discharge in the discharge cavity 1, the detection device is used to detect the temperature and pressure inside the oil pillow 2, and the oil hole is used to input insulating oil into the discharge cavity 1 or output the insulating oil in the discharge cavity 1.

[0039] Valve c11 is connected to the vacuum pump for evacuating the oil pillow 2, valve d12 is connected to the nitrogen source for injecting nitrogen into the oil pillow 2, and valve e13 is connected to the gas collecting device for collecting the gas in the oil pillow 2.

[0040] Example 5

[0041] The gas production measurement device for an arc fault in insulating oil disclosed in this embodiment includes a discharge chamber 1 for containing insulating oil 5 and nitrogen and an electrode pair arranged in the discharge chamber 1. The top of the discharge chamber 1 is connected to an oil pillow 2, and a detection device is provided in the oil pillow 2 and passes through the oil pillow 2. An oil hole is opened at the bottom of the discharge chamber 1.

[0042] The detection device includes a digital static temperature gauge 14 and a digital static pressure gauge 15 extending into the interior of the oil pillow 2.

[0043] In this embodiment, the discharge chamber 1 is used to contain insulating oil and nitrogen, the electrode pair is used to discharge in the discharge chamber 1, the detection device is used to detect the temperature and pressure inside the oil pillow 2, and the oil hole is used to input insulating oil into the discharge chamber 1 or output the insulating oil in the discharge chamber 1.

[0044] The digital static thermometer 14 works primarily by converting temperature changes into digital signals through a temperature sensor and displaying them on a display. Both the digital static thermometer 14 and the digital static pressure gauge 15 offer high measurement accuracy and are easily readable through digital displays.

[0045] Example 6

[0046] The disclosed device for measuring gas production during an arc fault in insulating oil includes a discharge chamber 1, an oil pillow 2, a connecting pipe 3, and an oil leak reservoir 4. The discharge chamber 1 is filled with insulating oil 5 and a trace amount of nitrogen 6. A pair of horizontal rod electrodes 7 are installed, with a copper wire 8 interposed between the electrodes to generate an arc. A valve a9 is installed at the bottom of the discharge chamber 1 for injecting and discharging the insulating oil 5. The oil pillow 2 is equipped with a digital static thermometer 14 and a digital static pressure gauge 15. The wall of the oil pillow 2 is equipped with a valve c11 for vacuuming, a valve d12 for injecting nitrogen into the oil pillow 2, and a valve e13 for recovering gas from the oil pillow 2. A valve b10 is installed on the connecting pipe 3 to connect and disconnect the discharge chamber 1 from the oil pillow 2. The device calculates gas production by measuring changes in gas pressure and temperature before and after an arc fault, which is of great significance for studying the pressure characteristics of arc faults in insulating oil.

[0047] The utility model proposes a device for measuring gas production during arc fault in insulating oil. The measurement process is as follows:

[0048] Step 1: Open valve a9 and fill the discharge chamber 1 with insulating oil 5 to a specified level (the discharge chamber 1 includes a body and a cover plate that are detachably sealed. The connecting pipe 3 passes through the cover plate and communicates with the interior of the body. The cover plate is opened during oil filling). Open valve b10 on the connecting pipe 3 to connect the discharge chamber 1 to the oil pillow 2 through the connecting pipe 3.

[0049] Step 2: Open valve c11 and use a vacuum pump to extract the residual air inside the oil pillow 2. Then open valve d12 and inject high-purity nitrogen into the oil pillow 2 until the pressure inside the oil pillow 2 reaches 1 atmosphere.

[0050] Step 3: Before arc discharge, the temperature and pressure of the gas in the oil pillow 2 are measured by the high-precision static thermometer 14 and the high-precision static pressure gauge 15. After the measurement, the valve b10 is closed;

[0051] Step 4: After the arc discharge ends, open valve b10 and wait until the static pressure gauge reading 15 stabilizes before measuring the temperature and pressure of the gas in the oil pillow 2 again.

[0052] Ignoring the change in the volume of the insulating oil 5, and considering the gas generated by the arc in the insulating oil 5 as an ideal gas, the gas production calculation formula is as follows:

[0053] (1)

[0054] Where ∆V is the gas production normalized to standard conditions, in L; p1 and p2 are the steady-state pressures before and after the experiment, in kPa; T1 and T2 are the steady-state temperatures before and after the experiment, in K; p0 is the standard pressure of 101.325 kPa, T0 is the standard temperature of 273.15 K, and V is the gas volume.

[0055] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0056] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0057] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A device for measuring gas production during arc faults in insulating oil, characterized in that: The invention comprises a discharge cavity (1) for containing insulating oil and nitrogen and an electrode pair arranged in the discharge cavity (1); the top of the discharge cavity (1) is connected to an oil pillow (2); a detection device passing through the oil pillow (2) is arranged in the oil pillow (2); and an oil hole is opened at the bottom of the discharge cavity (1).

2. The device for measuring gas production during arc fault in insulating oil according to claim 1, characterized in that: The discharge cavity (1) and the oil pillow (2) are connected via a connecting pipe (3), and a valve b (10) is provided on the connecting pipe (3).

3. The device for measuring gas production during arc fault in insulating oil according to claim 2, characterized in that: The discharge cavity (1) comprises a body and a cover plate which are detachably sealed and connected, and the connecting pipe (3) passes through the cover plate and communicates with the interior of the body.

4. The device for measuring gas production during arc fault in insulating oil according to claim 1, characterized in that: The electrode pair comprises two electrodes (7) whose ends extend out of the discharge cavity (1) and are connected to a power source, and a copper wire (8) is connected between the two electrodes (7).

5. The device for measuring gas production during arc fault in insulating oil according to claim 1, characterized in that: The oil hole at the bottom of the discharge cavity (1) is connected to a valve a (9), and the valve a (9) is connected to an insulating oil tank.

6. The device for measuring gas production during arc fault in insulating oil according to claim 1, characterized in that: The bottom of the oil pillow (2) is connected to valve c (11), valve d (12), and valve e (13), respectively. Valve c (11) is connected to a vacuum pump, valve d (12) is connected to a nitrogen source, and valve e (13) is connected to a gas collecting device.

7. The device for measuring gas production during arc fault in insulating oil according to claim 1, characterized in that: The detection device comprises a digital static temperature gauge (14) and a digital static pressure gauge (15) extending into the interior of the oil pillow (2).

8. The device for measuring gas production during arc fault in insulating oil according to claim 1, characterized in that: An oil leakage pool (4) is provided at the bottom of the discharge cavity (1).

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