A heating control method for adaptive breathing state and maintenance-free dehumidifier

Abstract

The present invention discloses a heating control method for adaptive breathing state and a maintenance-free dehumidifier, the method comprising: installing a flow monitoring device and a temperature and humidity monitoring device on a pipe connecting a dehumidifier body and a transformer, respectively monitoring the breathing state of the transformer and the internal temperature and humidity of the dehumidifier body; judging whether to start the silica gel regeneration program of the dehumidifier body according to the collected exhalation rate, temperature and humidity, so as to start the heating device inside the dehumidifier body to restore the water absorption capacity of the color-changing silica gel adsorbent in the dehumidifier body, and using the exhalation state of the transformer to discharge the steam water generated by the heating device during dehumidification. The present invention solves the problem that the hot steam generated by the existing maintenance-free dehumidifier body during the silica gel regeneration process invades the interior of the oil storage cabinet upward.

Description

Technical Field

[0001] The invention relates to the technical field of transformer desiccant bodies, in particular to a heating control method for adaptive breathing states and a maintenance-free desiccant. Background Art

[0002] The breathing state of the transformer is a key indicator for determining whether the overall oil and gas circuits are unobstructed. It is urgent to realize the digital improvement of the oil-immersed transformer desiccant, which will help to control the overall state of the transformer.

[0003] The transformer desiccant body is an important part of the transformer in the power system. It can protect the insulating oil inside the transformer from the invasion of external moisture and impurities, ensuring the insulation strength and operation safety of the transformer. During the operation of the transformer, due to the change of oil temperature, the volume of the internal oil will expand or contract, resulting in the need for gas exchange with the outside world. During the gas exchange process, the desiccant body can absorb the moisture and impurities in the incoming air through the internal desiccant to keep the oil dry and clean.

[0004] When the temperature of transformer oil rises, its volume expands and squeezes the capsule in the oil storage cabinet, exhausting the gas and keeping the internal pressure stable. When the temperature of transformer oil drops, its volume decreases, the capsule inhales the gas, and the silica gel inside the desiccant body prevents external humid air from entering the interior.

[0005] Current desiccant body designs usually rely on fixed ventilation and filtration mechanisms and cannot adapt to dynamic airflow changes. This may result in the hot steam generated by the existing maintenance-free desiccant body during silica gel regeneration, if it is in the inhalation state or the exhalation rate is too low, it may invade the oil storage cabinet capsule, thus affecting the oil quality and equipment performance.

[0006] Traditional maintenance methods mainly rely on regular inspections, which fail to effectively solve the problem of real-time monitoring of exhalation rate and its impact on equipment. Therefore, a transformer adaptive maintenance-free dehumidifier body based on dynamic airflow is needed, which can dynamically adjust to cope with changes in exhalation rate and prevent humid air from flowing into the transformer, thereby improving the reliability and operating efficiency of the transformer.

[0007] In the prior art, the invention patent with the patent publication number CN115621002A discloses a digital transformer desiccant and a transformer breathing flow monitoring method. When judging the desiccant, the control unit first starts the heating belt to generate heat that can evaporate water vapor from the silica gel barrel. The water vapor condenses into water droplets on the glass cover shell and flows into the funnel-shaped overflow groove processed on the lower cover, and the electromagnetic valve is started to discharge the desiccant through the drain port. However, if the desiccant body is in the inhalation state or the exhalation rate is too low, the water vapor may enter the oil storage cabinet capsule. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a heating control method for adaptive breathing state and a maintenance-free dehumidifier.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0010] A heating control method for adaptive breathing state, comprising:

[0011] Install the flow monitoring device and the temperature and humidity monitoring device on the pipe connecting the desiccant body and the transformer to monitor the breathing state of the transformer and the internal temperature and humidity of the desiccant body respectively;

[0012] According to the collected exhalation rate, temperature and humidity, it is determined whether to start the silica gel regeneration program of the desiccant body, so as to start the heating device inside the desiccant body to restore the water absorption capacity of the color-changing silica gel adsorbent in the desiccant body, and use the exhalation state of the transformer to discharge the steam water generated by the heating device during dehumidification.

[0013] Advantages: The present invention utilizes the exhalation state of the transformer itself to discharge the steam water generated when the heating device is dehumidified, which can effectively prevent the hot steam caused by the transformer being in the inhalation state or the exhalation rate being too low from entering the transformer oil storage cabinet, thereby contaminating the oil quality and affecting the equipment performance.

[0014] In one embodiment of the present invention, the steam water generated by the heating device during dehumidification is discharged, including:

[0015] When the temperature and humidity monitoring device detects that the humidity inside the desiccant body is greater than the humidity threshold, the silica gel regeneration program is adjusted to the waiting state for heating;

[0016] Determine the current breathing state of the transformer based on the monitoring data of the flow monitoring device;

[0017] If the transformer is in the exhalation state and the exhalation rate is greater than the set minimum exhalation rate, the heating device is turned on and the silica gel regeneration program is started; otherwise, the silica gel regeneration program is not started temporarily and will be started when the transformer exhalation rate is greater than the minimum exhalation rate.

[0018] In one embodiment of the present invention, after the silica gel regeneration program is started, if it is monitored that the transformer exhalation rate is less than the minimum exhalation rate, the heating device is turned off, the silica gel regeneration program is suspended, and it is restarted when the transformer exhalation rate is greater than the minimum exhalation rate.

[0019] In one embodiment of the present invention, after the silica gel regeneration program is started, when the temperature and humidity monitoring device detects that the humidity inside the desiccant body is lower than the humidity threshold, the heating device is turned off and the silica gel regeneration program is stopped.

[0020] In one embodiment of the present invention, the minimum exhalation rate is that the transformer is in an exhalation state, and the exhalation rate is sufficient to discharge the hot steam generated by heating.

[0021] In one embodiment of the present invention, the minimum exhalation rate is obtained by the following formula:

[0022] ;

[0023] In the formula, Expressed as the minimum exhalation rate, P Expressed as the power of the heating device, ρ Expressed as air density, r Expressed as the breathing duct radius.

[0024] The present invention also provides a maintenance-free desiccator, which applies the above-mentioned adaptive breathing state heating control method, including: a desiccator body; a flow monitoring device and a temperature and humidity monitoring device are installed on the pipeline connecting the desiccator body and the transformer.

[0025] In one embodiment of the present invention, the length of the breathing duct of the dehumidifier body is optimized based on the breathing duct radius parameter and the maximum flow rate in the breathing duct.

[0026] In one embodiment of the present invention, the length of the breathing duct of the dehumidifier body is obtained by the following formula:

[0027] ;

[0028] In the formula, L Expressed as the length of the breathing tube, ρ Expressed as air density, r Expressed as the breathing duct radius, It is expressed as the measured value of the maximum flow rate in the breathing tube. ψ Expressed as the dynamic viscosity of air.

[0029] In one embodiment of the present invention, if there is no actual measured value of the maximum flow rate in the breathing duct, a reference value of the maximum flow rate in the breathing duct is obtained based on the model of the dehumidifier body.

[0030] Compared with the prior art, the beneficial effect of the present invention is that it solves the problem that the hot steam generated by the existing maintenance-free desiccator during the silica gel regeneration process invades the oil storage cabinet upward. The present invention controls the start-up of the heating rod and the regeneration of silica gel according to the change of the dynamic airflow of the transformer. The start-up condition of the heating rod is: the exhalation rate reaches the value required by the desiccator of this model, and the humidity reaches the set requirement. This mechanism can effectively prevent the hot steam caused by the transformer being in the inhalation state or the exhalation rate being too low from entering the transformer oil storage cabinet, thereby contaminating the oil quality and affecting the equipment performance.

[0031] In addition, the present invention also optimizes the length of the breathing duct according to the parameters of different models of desiccators and the radius of the breathing duct, ensures smooth airflow, and avoids affecting the breathing efficiency due to excessive duct resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The present invention is a flow chart of a heating control method for adaptive breathing state according to an embodiment of the present invention.

[0033] Figure 2 The invention discloses a maintenance-free desiccant according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to facilitate those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention is further described in conjunction with the accompanying drawings of the specification.

[0035] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0036] Example 1

[0037] See also Figure 1 As shown, the present invention discloses a heating control method for adaptive breathing state, comprising:

[0038] S10, installing a flow monitoring device and a temperature and humidity monitoring device on a pipe connecting the desiccant body and the transformer, and monitoring the breathing state of the transformer and the internal temperature and humidity of the desiccant body respectively.

[0039] See also Figure 1 and Figure 2 As shown, in one embodiment of the present invention, the desiccator body includes a first silicone tube 21, a second silicone tube 22, a connecting plate 23 and a control chamber 24. The first silicone tube 21, the second silicone tube 22 are detachably connected to the connecting plate 23, and the desiccator body is connected to the transformer through the mounting flange 25. The pipes of the first silicone tube 21 and the second silicone tube 22 pass through the connecting plate 23 and the mounting flange 25 and are connected to the oil storage cabinet structure of the transformer.

[0040] In this embodiment, a heating device is provided at the center of the first silicone tube 21 and the second silicone tube 22, and a color-changing silica gel adsorbent is stored inside. The flow monitoring device 11 is fixed in the sleeve of the mounting flange 25 in a nested manner, and the probe of the temperature and humidity monitoring device 12 is installed inside the mounting flange 25. An integrated circuit board is provided in the control room 24, and is communicatively connected with the flow monitoring device 11, the temperature and humidity monitoring device 12, and the heating device, and a silica gel regeneration program is stored inside. Specifically, in this embodiment, the flow monitoring device 11 is a flow sensor, the temperature and humidity monitoring device 12 is a temperature and humidity sensor, and the heating device is a heating rod.

[0041] In this embodiment, the first silicone tube 21 and the second silicone tube 22 are provided with an isolation tube, and the isolation tube is provided with a protective tube. A pressure sensor is also provided at the location where the desiccant body is connected to the mounting flange 25 to monitor the pressure inside the first silicone tube 21 and the second silicone tube 22. Furthermore, the output signal of the temperature and humidity monitoring device is transmitted through a wired transmission line, which extends from the front of the mounting flange 25 and is connected to the controller in the integrated circuit board, so that the temperature and humidity signals inside the desiccant body are collected at the circuit board, and the outside of the line is wrapped with a heat shrink tube to prevent the line from short-circuiting when it encounters water.

[0042] S20, based on the collected exhalation rate, temperature and humidity, determines whether to start the silica gel regeneration program of the desiccant body, so as to start the heating device inside the desiccant body to restore the water absorption capacity of the color-changing silica gel adsorbent in the desiccant body, and utilizes the exhalation state of the transformer to discharge the steam water generated by the heating device during dehumidification.

[0043] In one embodiment of the present invention, the silica gel regeneration procedure is started when the temperature, humidity and respiration volume collected by the sensor reach specific conditions. At this time, the heating rod will heat the color-changing silica gel adsorbent to restore its water absorption capacity. The color-changing silica gel adsorbent is used to absorb water. When the color-changing silica gel adsorbent used to store water reaches a certain saturation, its water absorption effect will gradually weaken until it fails. At this time, it is necessary to restore its water absorption capacity by heating the color-changing silica gel adsorbent. In this embodiment, the silica gel regeneration procedure is not limited, and conventional technology is used.

[0044] In this embodiment, the steam water generated by the heating device during dehumidification is discharged, including:

[0045] S21, when the temperature and humidity monitoring device detects that the humidity inside the desiccant body is greater than the humidity threshold, the silica gel regeneration program is adjusted to the heating state.

[0046] In this embodiment, the humidity threshold is set to 30% RH.

[0047] S22, judging the current breathing state of the transformer according to the monitoring data of the flow monitoring device.

[0048] S23, if the transformer is in the exhalation state, and the exhalation rate is greater than the set minimum exhalation rate, the heating device is turned on and the silica gel regeneration program is started; otherwise, the silica gel regeneration program is not started temporarily, and it is started again when the transformer exhalation rate is greater than the minimum exhalation rate.

[0049] In this embodiment, the silica gel regeneration program is started only when the transformer is in an exhalation state and the exhalation rate is sufficient to discharge the hot steam generated by heating. To prevent the hot steam from entering the transformer oil storage cabinet capsule, a minimum exhalation rate needs to be set in m / s.

[0050] By monitoring the breathing operation of different types of dehumidifiers during heating, the minimum exhalation rate under 5 experimental models was obtained. The radius of the breathing tube was 0.03m, and the air density was 1.29kg / m³. The experimental data are shown in the following table.

[0051] Table 1 Minimum exhalation rate of different types of dehumidifiers

[0052]

[0053] The minimum exhalation rate formula obtained by fitting the experimental data is as follows:

[0054] ;

[0055] In the formula, Expressed as the minimum exhalation rate, P It is expressed as the power of the heating device, in W. ρ Expressed as air density in kg / m³, r Expressed as the radius of the breathing duct, unit: m.

[0056] In this embodiment, after the silica gel regeneration program is started, if it is monitored that the transformer exhalation rate is less than the minimum exhalation rate, the heating device is turned off, the silica gel regeneration program is suspended, and it is restarted when the transformer exhalation rate is greater than the minimum exhalation rate.

[0057] In this embodiment, after the silica gel regeneration program is started, when the temperature and humidity monitoring device detects that the humidity inside the desiccant body is lower than the humidity threshold, the heating device is turned off and the silica gel regeneration program is stopped.

[0058] In one embodiment of the present invention, when designing a maintenance-free desiccator, it is necessary to enable the desiccator to appropriately monitor the dynamic airflow. Through fluid mechanics simulation, the design of the desiccator is optimized, and flow sensors of different models are selected so that the breathing duct can not only ensure the smooth flow of dynamic airflow, but also monitor the flow in both directions in a timely manner. At the same time, the airflow adaptability of the duct and the stability of the material under different extreme working conditions such as humidity, high temperature and low temperature are tested, and good test results are obtained.

[0059] In the existing transformer operation data, there is a lack of sufficient real-time monitoring data, especially data on airflow dynamics and exhalation rate, which makes the basic information for designing adaptive dehumidifiers insufficient. By hanging a dehumidifier with flow monitoring function on two main transformers in operation for half a year, the breathing data of the transformers were collected and fitted with the simulation. It was found that the error was less than 3%, which shows that the simulation results are good and the data obtained from the experiment are of reference value.

[0060] During the regeneration process of the desiccant silica gel, the heating efficiency may decrease due to the dynamic changes of the airflow, and the water vapor may enter the capsule. An automatic control system has been developed to adjust the working state of the desiccant according to real-time data such as flow, temperature and humidity, to ensure timely regeneration when the silica gel is saturated, and to specify corresponding operating procedures for the regeneration schemes of silica gel with different capacities.

[0061] In this embodiment, the determination of the minimum exhalation rate can prevent water vapor from entering the oil storage cabinet capsule under heating conditions, thereby avoiding potential failure risks and equipment damage. The moisture absorption efficiency is ensured, the normal operation of the system is ensured, and the silica gel regeneration process is optimized. Although setting the minimum exhalation rate may extend the heating time of silica gel regeneration, this does not affect the regeneration effect of silica gel, but further improves the operating reliability and efficiency of the transformer.

[0062] Example 2

[0063] See also Figure 1 and Figure 2 As shown, the present invention also provides a maintenance-free dehumidifier, which uses the heating control method of the adaptive breathing state described in Example 1, including: a dehumidifier body. A flow monitoring device 11 and a temperature and humidity monitoring device 12 are installed on the pipeline connecting the dehumidifier body and the transformer.

[0064] In one embodiment of the present invention, it is necessary to compare the exhalation state of the transformer and the real-time exhalation rate with the minimum exhalation rate to discharge the hot steam, which shows the importance of the exhalation rate, and the exhalation rate is related to the length of the breathing duct of the dehumidifier. Therefore, this embodiment optimizes the length of the breathing duct. Specifically, according to the breathing duct radius parameter and the maximum flow rate in the breathing duct, the length of the breathing duct of the dehumidifier body is optimized, as shown in the following formula:

[0065] ;

[0066] In the formula, L It is expressed as the length of the breathing tube, in meters. ρ Expressed as air density, r Expressed as the breathing duct radius, It is expressed as the maximum measured flow rate in the breathing pipe, in m / s. ψ Expressed as the dynamic viscosity of air, unit N·s / m 2 Among them, the actual measured value of the maximum flow rate in the breathing duct can be obtained by a flow monitoring device in this embodiment.

[0067] In another embodiment, if the breathing duct is optimized without flow sensor to measure the maximum flow rate, the maximum flow rate reference value in the breathing duct can be obtained according to the model of the dehumidifier, and the following reference table is given in this embodiment:

[0068] Table 2 Reference values ​​for maximum flow rates of the breathing tube of the dehumidifier

[0069]

[0070] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any reference numerals in the claims should not be regarded as limiting the claims involved.

[0071] The above-described embodiments merely represent implementation methods of the invention. The protection scope of the present invention is not limited to the above-described embodiments. For those skilled in the art, several modifications and improvements may be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A heating control method for adaptive breathing state, characterized in that: include: Dehumidifier body, flow monitoring device, temperature and humidity monitoring device; Install the flow monitoring device and the temperature and humidity monitoring device on the pipe connecting the desiccant body and the transformer to monitor the breathing state of the transformer and the internal temperature and humidity of the desiccant body respectively; According to the collected exhalation rate, temperature and humidity, determine whether to start the silica gel regeneration program of the dehumidifier body, so as to start the heating device inside the dehumidifier body to restore the water absorption capacity of the color-changing silica gel adsorbent in the dehumidifier body, and use the exhalation state of the transformer to discharge the steam water generated by the heating device during dehumidification, including: When the temperature and humidity monitoring device detects that the humidity inside the desiccant body is greater than the humidity threshold, the silica gel regeneration program is adjusted to the waiting state for heating; Determine the current breathing state of the transformer based on the monitoring data of the flow monitoring device; If the transformer is in the exhalation state, and the exhalation rate is greater than the set minimum exhalation rate, the heating device is turned on and the silica gel regeneration program is started; otherwise, the silica gel regeneration program is not started temporarily, and it is started again when the transformer exhalation rate is greater than the minimum exhalation rate; The minimum exhalation rate is obtained by the following formula: ； In the formula, Expressed as the minimum exhalation rate, P Expressed as the power of the heating device, ρ Expressed as air density, r Expressed as the breathing duct radius.

2. The heating control method according to claim 1, characterized in that: When the silica gel regeneration program is started, if it is monitored that the transformer exhalation rate is less than the minimum exhalation rate, the heating device is turned off, the silica gel regeneration program is suspended, and it will continue to start when the transformer exhalation rate is greater than the minimum exhalation rate.

3. The heating control method according to claim 1, characterized in that: After the silica gel regeneration program is started, when the temperature and humidity monitoring device detects that the humidity inside the desiccant body is lower than the humidity threshold, the heating device is turned off and the silica gel regeneration program is stopped.

4. The heating control method according to claim 1, characterized in that: The minimum exhalation rate is when the transformer is in the exhalation state and the exhalation rate is sufficient to discharge the hot steam generated by heating.

5. A maintenance-free dehumidifying breather, using the heating control method for adaptive breathing state according to any one of claims 1 to 4, characterized in that: include: Desiccant body; a flow monitoring device and a temperature and humidity monitoring device are installed on the pipeline connecting the desiccant body and the transformer.

6. The maintenance-free dehumidifying breather according to claim 5, characterized in that: The length of the breathing duct of the dehumidifier body is optimized according to the breathing duct radius parameter and the maximum flow rate in the breathing duct.

7. The maintenance-free dehumidifying breather according to claim 5, characterized in that: The length of the breathing tube of the dehumidifier body is obtained by the following formula: ； In the formula, L Expressed as the length of the transformer's breathing duct, ρ Expressed as air density, r Expressed as the breathing duct radius, It is expressed as the measured value of the maximum flow rate in the breathing tube. ψ Expressed as the dynamic viscosity of air.

8. The maintenance-free dehumidifying breather according to claim 5, characterized in that: If there is no actual measured value of the maximum flow rate in the breathing duct, obtain the reference value of the maximum flow rate in the breathing duct based on the model of the dehumidifier body.

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