Gas chromatography detection device protection system for dissolved gas in transformer oil

Abstract

The invention relates to a protection system of a gas chromatography detection device for dissolved gas in transformer oil, and belongs to the technical field of electronic elements. The protection system comprises a filter, a heater, a gas supply device, a first three-way valve and a second three-way valve, the first three-way valve is provided with a connector A, a connector B and a connector C, and the second three-way valve is provided with a connector a, a connector b and a connector c. According to the gas chromatography detection device, the filter is arranged and is used for adsorbing oil mist or impurities in gas removed by the degassing device, so that a gas chromatographic column and a gas sensor in the gas chromatography detection device can be effectively protected, and the gas chromatography detection device is prevented from losing efficacy due to the oil mist or the impurities; the air supply device, the heater, the filter and the first three-way valve are sequentially connected through the pipeline to form a reverse blowing line, and the filter element of the filter is subjected to reverse blowing recovery, so that the filter can continuously and effectively play a role in filtering.

Description

Technical Field

[0001] The invention relates to the technical field of transformer fault detection, and in particular to a protection system for a gas chromatography detection device of dissolved gas in transformer oil. Background Art

[0002] Transformers are important equipment in the power system. They play the role of power conversion and hub in the power network, which directly affects the safe and reliable operation of the power system. Compared with dry-type transformers, oil-immersed power transformers are more widely used. Generally speaking, the changes in the oil and gas composition in oil-immersed power transformers are mainly related to the insulating oil and the environmental conditions in which they are located. When a latent fault occurs inside the transformer, under the action of heat and electricity, the transformer oil and solid insulating materials will gradually age and decompose, producing various low-molecular hydrocarbons and gases such as CO and CO2. The analysis of dissolved gases in transformer oil can determine the type of transformer fault and predict its future development trend. The analysis of dissolved gases in transformer oil is one of the important means to monitor the operating status of the transformer, and gas chromatography plays a key role in the analysis of transformer oil gas.

[0003] When there is a fault inside the transformer, different types of gases will be generated and dissolved in the transformer oil. By collecting transformer oil samples, the gases dissolved in the oil are separated using a degassing device, and then the gases are analyzed using a gas chromatograph. Different fault types will produce specific gas combinations. By analyzing the types, contents and proportions of these gases, the operating status and fault type of the transformer can be determined. In the gas chromatography detection method, there are two key parts that determine its performance and service life, one is the gas chromatography column and the other is the gas sensor; the components in the sample are repeatedly distributed in the chromatographic column with the flow of the carrier gas. Due to the different affinities between the two phases, the time they flow out of the chromatographic column is also different, thereby achieving separation. The commonly used gas sensor is a contact combustion gas sensor, which can convert the gas flowing through the sensor into heat by combustion and further convert it into an electrical signal through a thermistor, thereby measuring the concentration of the gas components released from the transformer oil. Since the previous stage of the gas chromatography detection device is the gas separation function module in the transformer oil, in the process of separating the dissolved gas, it is inevitable that part of the oil mist or even part of the impurities will be brought out during the process of using vibration, stirring or piston, and mixed in the gas and output together. The gas chromatography column will adsorb the oil mist or impurities mixed in the gas in the process of separating the different components of the gas removed from the transformer oil, thereby reducing the separation degree of the gas chromatography column or even completely failing; and the gas sensor, especially the contact combustion type gas sensor, is provided with a catalyst. The oil mist or impurities mixed in the gas removed from the transformer oil enter the gas sensor and adhere to the surface of the catalyst, which will poison the catalyst, thereby reducing the activity of the gas sensor or even completely failing.

[0004] Therefore, it is very necessary to develop a protection system for a gas chromatography detection device of dissolved gases in transformer oil to avoid failure of the gas chromatography detection device. Summary of the invention

[0005] The object of the present invention is to overcome the deficiencies of the prior art and provide a protection system for a gas chromatography detection device of dissolved gases in transformer oil.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A protective system for a gas chromatography detection device of dissolved gas in transformer oil comprises a filter, a heater, an air supply device, a first three-way valve and a second three-way valve, wherein the first three-way valve has an interface A, an interface B and an interface C, and the second three-way valve has an interface a, an interface b and an interface c, the interface A of the first three-way valve is connected to a degassing device in the transformer through a pipeline, the interface B of the first three-way valve is connected to an air inlet of the filter through a pipeline, the air outlet of the filter is connected to an interface a of the second three-way valve through a pipeline, the interface b of the second three-way valve is connected to a gas chromatography detection device through a pipeline, the interface c of the second three-way valve is connected to an air outlet of the heater, and the air inlet of the heater is connected to the air supply device through a pipeline.

[0008] As a preferred embodiment of the present invention, the heater includes a shell and a heat transfer tube, the shell is provided with an air inlet, an air outlet and a heating chamber connecting the inlet and the outlet, the heat transfer tube is arranged in the heating chamber, one end of the heat transfer tube is connected to the air inlet of the heater, and the other end of the heat transfer tube is connected to the air outlet of the heater, and a heating element is embedded and installed on the inner wall of the heating chamber.

[0009] Furthermore, the heat transfer tube is a serpentine structure.

[0010] Furthermore, a temperature sensor is provided at the air inlet of the heater.

[0011] Furthermore, the heating element includes at least one of a heating coil, a heating rod and a heating rod.

[0012] Furthermore, the heat transfer tube is made of stainless steel.

[0013] Furthermore, the shell is made of aluminum oxide.

[0014] As a preferred embodiment of the present invention, the filter element in the filter is made of brass.

[0015] As a preferred embodiment of the present invention, the interface C of the first three-way valve is connected to an exhaust pipe.

[0016] As a preferred embodiment of the present invention, the protection system for the gas chromatography detection device for dissolved gas in transformer oil further includes a controller, and the first three-way valve, the second three-way valve, the heater and the gas supply device are respectively connected to the controller.

[0017] Furthermore, a flow meter is provided on the pipeline between the interface b of the second three-way valve and the gas chromatography detection device, and the flow meter is connected to the controller.

[0018] Furthermore, the controller stores a preset flow rate threshold. The controller obtains gas flow rate information according to a time sequence and compares the current gas flow rate with the preset flow rate threshold. If the current gas flow rate is less than the preset flow rate threshold, the protection system switches from the gas guide working state to the backblowing working state.

[0019] Further, at least one flow meter is respectively arranged on the pipeline between the interface b of the first three-way valve and the air inlet of the filter, the pipeline between the air outlet of the filter and the interface a of the second three-way valve, and the pipeline between the interface b of the second three-way valve and the gas chromatography detection device, and the total number of flow meters in the protection system is n;

[0020] The controller stores a flow rate difference threshold value. The controller obtains and stores the gas flow rate information from the flow meter at preset time intervals, calculates the difference between the gas flow rate at the previous moment and the gas flow rate at the current moment in sequence, and accumulates and sums the n obtained differences at an interval of the preset time between the previous moment and the current moment to obtain a cumulative summation result, compares the cumulative summation result with the flow rate difference threshold value, and if the summation result is less than the flow rate difference threshold value, the protection system switches from the gas guide working state to the backwash working state.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention provides a filter and uses the filter to absorb the oil mist or impurities in the gas through the degassing device, thereby effectively protecting the gas chromatographic column and the gas sensor in the gas chromatographic detection device and preventing the gas chromatographic detection device from failing due to the oil mist or impurities.

[0023] The present invention sequentially connects the air supply device, the heater, the filter and the first three-way valve through a pipeline to form a backflush circuit, and backflushs and restores the filter element of the filter, so that the filter can continuously and effectively play a filtering role. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of a protection system for a gas chromatography detection device for dissolved gas in transformer oil provided by the present invention;

[0025] Figure 2 This is a schematic structural diagram of the heater provided by the present invention. DETAILED DESCRIPTION

[0026] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0027] See also Figures 1-2 The present invention provides a protective system for a gas chromatography detection device of dissolved gas in transformer oil, comprising a filter 2, a heater 4, an air supply device 5, a first three-way valve 1 and a second three-way valve 3, wherein the first three-way valve 1 has an interface A, an interface B and an interface C, and the second three-way valve 3 has an interface a, an interface b and an interface c, the interface A of the first three-way valve 1 is connected to a degassing device in the transformer through a pipeline, the interface B of the first three-way valve 1 is connected to an air inlet of the filter 2 through a pipeline, the air outlet of the filter 2 is connected to an interface a of the second three-way valve 3 through a pipeline, the interface b of the second three-way valve 3 is connected to a gas chromatography detection device through a pipeline, the interface c of the second three-way valve 3 is connected to an air outlet of the heater 4, and the air inlet of the heater 4 is connected to the air supply device 5 through a pipeline.

[0028] The present invention sets a filter 2, and utilizes the filter 2 to absorb the oil mist or impurities in the gas through the degassing device, thereby effectively protecting the gas chromatographic column and the gas sensor in the gas chromatographic detection device and preventing the gas chromatographic detection device from failing due to the oil mist or impurities. The present invention sequentially connects the gas supply device 5, the heater 4, the filter 2 and the first three-way valve 1 through a pipeline to form a backflush circuit, and backflushs and restores the filter element of the filter 2, so that the filter 2 can continue to effectively perform a filtering function.

[0029] In one embodiment, the heater 4 includes a shell 41 and a heat transfer tube 42. The shell 41 is provided with an air inlet, an air outlet, and a heating chamber 44 connecting the inlet and the outlet. The heat transfer tube 41 is arranged in the heating chamber 44. One end of the heat transfer tube 42 is connected to the air inlet of the heater 4, and the other end of the heat transfer tube 42 is connected to the air outlet of the heater 4. A heating element is embedded in the inner wall of the heating chamber 44.

[0030] Specifically, the heat transfer tube 42 is a serpentine structure.

[0031] Specifically, a temperature sensor 43 is provided at the air outlet of the heater 4 .

[0032] Specifically, the heating element includes at least one of a heating coil, a heating rod and a heating rod.

[0033] Specifically, the heat transfer tube 42 is made of stainless steel.

[0034] Specifically, the housing 41 is made of aluminum oxide.

[0035] In one embodiment, the filter element in the filter 2 is made of brass.

[0036] In one embodiment, the port C of the first three-way valve 1 is connected to an exhaust pipe.

[0037] In one embodiment, the protection system for the gas chromatography detection device for dissolved gas in transformer oil further includes a controller 6 , and the first three-way valve 1 , the second three-way valve 3 , the heater 4 , and the gas supply device 5 are respectively connected to the controller 6 .

[0038] The temperature sensor 43 is used to detect the real-time temperature at the air outlet of the heater 4, and transmits the detected real-time temperature information to the controller 6. The controller 6 compares the real-time temperature value with the preset temperature value. If the real-time temperature reaches or exceeds the preset temperature value, the controller 6 issues an instruction to cut off the power supply to stop the heating element from heating; conversely, if the real-time temperature is lower than the preset temperature value, the controller 6 controls the heating element to turn on the power supply to allow the heating rod to continue heating.

[0039] Specifically, a flow meter 7 is provided on the pipeline between the interface b of the second three-way valve 3 and the gas chromatography detection device. The flow meter 7 is used to measure the flow rate information of the gas flowing through the pipeline where the flow meter 7 is located. The flow meter 7 is connected to the controller 6.

[0040] In the present invention, the first three-way valve 1 and the second three-way valve 3 are both three-way solenoid valves.

[0041] Specifically, a preset flow rate threshold is stored in the controller 6. The controller 6 obtains the gas flow rate information according to the time sequence, and compares the current gas flow rate with the preset flow rate threshold. If the current gas flow rate is less than the preset flow rate threshold, the protection system is switched from the gas guide working state to the backblowing working state.

[0042] Specifically, at least one flow meter 7 is respectively arranged on the pipeline between the interface b of the first three-way valve 1 and the air inlet of the filter 2, the pipeline between the air outlet of the filter 2 and the interface a of the second three-way valve 3, and the pipeline between the interface b of the second three-way valve 3 and the gas chromatography detection device; the number of flow meters 7 is n; the controller 6 stores a flow rate difference threshold, and the controller 6 obtains and stores the gas flow rate from the flow meter 7 at preset time intervals, calculates the difference between the gas flow rate at the previous moment and the gas flow rate at the current moment in sequence, and the preset time is separated between the previous moment and the current moment, and the n obtained differences are accumulated and summed to obtain a cumulative summation result, and the cumulative summation result is compared with the flow rate difference threshold. If the summation result is less than the flow rate difference threshold, the protection system switches from the gas guide working state to the backwash working state. The present invention judges the state of the filter 2 according to the accumulation of the gas flow rate difference change, so that the result is more accurate.

[0043] In the present invention, when the protection system is in the gas-conducting working state, interface A of the first three-way valve 1 is connected to interface B, and interface a of the second three-way valve 3 is connected to interface c; the gas degassing through the degassing device flows through interface A and interface B of the first three-way valve 1, the filter 2, interface a and interface c of the second three-way valve in sequence, and then enters the gas chromatography detection device.

[0044] When the protection system is in the backwash working state, the interface B of the first three-way valve 1 is connected to the interface C, the interface c of the second three-way valve 3 is connected to the interface a, the heater 4 and the air supply device 5 are working, and the clean gas output by the air supply device 5 is heated by the heater 4, and then flows through the interface c and interface a of the second three-way valve 3, the filter 2, and the interface B and interface C of the first three-way valve 1 in sequence, thereby realizing the backwash function of the filter 2.

[0045] In the description of the present invention, it should be noted that the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. All directional indicators (such as up and down) in the present invention are only used to explain the relative position relationship, movement, etc. between the various parts under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0046] In the description of the present invention, it should also be noted that the terms "include", "have" and any variations thereof are intended to cover non-exclusive inclusions.

[0047] For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A protection system for a gas chromatography detection device for dissolved gas in transformer oil, characterized in that: The utility model comprises a filter, a heater, an air supply device, a first three-way valve and a second three-way valve, wherein the first three-way valve has interfaces A, B and C, the second three-way valve has interfaces a, b and c, the interface A of the first three-way valve is connected to the degassing device in the transformer through a pipeline, the interface B of the first three-way valve is connected to the air inlet of the filter through a pipeline, the air outlet of the filter is connected to the interface a of the second three-way valve through a pipeline, the interface b of the second three-way valve is connected to the gas chromatography detection device through a pipeline, the interface c of the second three-way valve is connected to the air outlet of the heater, and the air inlet of the heater is connected to the air supply device through a pipeline.

2. The protective system for gas chromatography detection device of dissolved gas in transformer oil according to claim 1, characterized in that: The heater includes a shell and a heat transfer tube. The shell is provided with an air inlet, an air outlet and a heating chamber connecting the inlet and the outlet. The heat transfer tube is arranged in the heating chamber. One end of the heat transfer tube is connected to the air inlet of the heater, and the other end of the heat transfer tube is connected to the air outlet of the heater. A heating element is embedded and installed on the inner wall of the heating chamber.

3. The protective system for gas chromatography detection device of dissolved gas in transformer oil according to claim 2, characterized in that: The heat transfer tube is a serpentine structure.

4. The protective system for gas chromatography detection device of dissolved gas in transformer oil according to claim 2, characterized in that: A temperature sensor is arranged at the air inlet of the heater.

5. The protective system for gas chromatography detection device of dissolved gas in transformer oil according to claim 2, characterized in that: The heating element includes at least one of a heating coil, a heating rod and a heating rod.

6. The protective system for gas chromatography detection device of dissolved gas in transformer oil according to claim 2, characterized in that: The heat transfer tube is made of stainless steel, the shell is made of alumina, the filter element in the filter is made of brass, and the interface C of the first three-way valve is connected to an exhaust pipe.

7. The protective system for gas chromatography detection device of dissolved gas in transformer oil according to claim 1, characterized in that: It also includes a controller, and the first three-way valve, the second three-way valve, the heater and the air supply device are respectively connected to the controller.

8. The protective system for gas chromatography detection device of dissolved gas in transformer oil as claimed in claim 7, characterized in that: A flow meter is provided on the pipeline between the interface b of the second three-way valve and the gas chromatography detection device, and the flow meter is connected to the controller.

9. The protective system for gas chromatography detection device of dissolved gas in transformer oil as claimed in claim 8, characterized in that: The controller stores a preset flow rate threshold. The controller obtains gas flow rate information according to a time sequence and compares the current gas flow rate with the preset flow rate threshold. If the current gas flow rate is less than the preset flow rate threshold, the protection system switches from the gas guide working state to the backblowing working state.

10. The protective system for gas chromatography detection device of dissolved gas in transformer oil according to claim 7, characterized in that: At least one flow meter is respectively arranged on the pipeline between the interface b of the first three-way valve and the air inlet of the filter, the pipeline between the air outlet of the filter and the interface a of the second three-way valve, and the pipeline between the interface b of the second three-way valve and the gas chromatography detection device; the total number of flow meters in the protection system is n; The controller stores a flow rate difference threshold value. The controller obtains and stores the gas flow rate from the flow meter at preset time intervals, calculates the difference between the gas flow rate at the previous moment and the gas flow rate at the current moment in sequence, and accumulates and sums the n obtained differences between the previous moment and the current moment at the preset time interval to obtain a cumulative summation result, compares the cumulative summation result with the flow rate difference threshold value, and if the summation result is less than the flow rate difference threshold value, the protection system switches from the gas guide working state to the backwash working state.

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