Transformer maintenance-free moisture absorber and control method thereof

Abstract

The application provides a transformer maintenance-free moisture absorber and a control method thereof. When the transformer maintenance-free moisture absorber is vertically installed and breathes through an outer filter screen and a desiccant, impurities and moisture in the entering air are removed, real-time monitoring is performed through a built-in temperature and humidity sensor, and water in the desiccant is automatically removed through heating control. The transformer maintenance-free moisture absorber comprises a control box, a support is bolted to one side of the control box, a fixed sensing head mounting block and a second outlet are arranged on the outer side of the support, one end of a fixed frame is connected to the inner side of the support, a plurality of heating sheet fixing frames are arranged on the fixed frame, corresponding heating sheets are fixed on the heating sheet fixing frames, an outer filter screen is arranged on the outer side of the fixed frame, a glass cover is arranged on the outer side of the outer filter screen, an outer filter screen flange is connected to the other end of the fixed frame, an outer filter screen blocking plate is connected to the outer filter screen flange, a rear seat is connected to the outer filter screen blocking plate, and the inner side of the outer filter screen is filled with a desiccant.

Description

Technical Field

[0001] This invention relates to the field of substation maintenance technology, specifically to a maintenance-free dehumidifier for transformers and its control method. Background Technology

[0002] The insulating strength of transformer oil is one of the key factors ensuring the normal operation of transformers. If moisture and impurities are mixed into the transformer oil, its insulating strength will decrease, leading to equipment failure. As a critical piece of equipment in power transmission and distribution systems, the operating condition of transformers directly affects the stability and security of the power system. Therefore, higher requirements are placed on the maintenance and upkeep of transformers.

[0003] During transformer operation, changes in load or ambient temperature cause the transformer oil to expand and contract, forcing the gas inside the oil conservator to "breathe" through a dehumidifier. During this process, impurities and moisture from the air can enter the transformer, affecting the insulation strength of the transformer oil. Therefore, a dehumidifier capable of efficiently removing these impurities and moisture is needed to optimize the transformer's "breathing" process.

[0004] While traditional dehumidifiers can filter impurities and moisture from the air to some extent, they have high maintenance costs and the following drawbacks:

[0005] Desiccant needs to be replaced regularly: The desiccant in traditional dehumidifiers will become saturated after absorbing a certain amount of moisture, and needs to be replaced manually and regularly. This not only increases the workload of maintenance, but may also lead to a decrease in the moisture absorption effect if the replacement is not timely.

[0006] Inconvenient maintenance: Dehumidifiers are usually installed high up on the transformer or in hard-to-reach locations, making operations such as changing the desiccant and cleaning the filter difficult and dangerous.

[0007] Unable to monitor in real time: Traditional dehumidifiers lack real-time humidity monitoring and automatic control functions, and cannot respond promptly to the state of desiccant saturation, thus affecting the moisture absorption effect.

[0008] This not only increases the workload of on-site personnel but also increases expenses. Furthermore, improper disposal of the waste generated after replacement can pollute the environment. In addition, traditional dehumidifiers have limitations in dehumidification efficiency and intelligence, failing to meet the stability and intelligence requirements of modern power systems.

[0009] Therefore, considering the needs of the power industry, the limitations of traditional dehumidifiers, the protection of transformer oil insulation strength, the requirements of intelligent and green environmental protection, and the optimization of transformer breathing process, it is urgent to develop a maintenance-free dehumidifier. The emergence of this maintenance-free dehumidifier not only solves the problems of traditional dehumidifiers, but also improves the stability and reliability of the equipment, providing a strong guarantee for the safe and stable operation of the power system. Summary of the Invention

[0010] This invention aims to address the technical deficiencies of existing technologies by providing a maintenance-free dehumidifier for transformers and its control method. When vertically installed, the dehumidifier breathes through an outer filter and desiccant, removing impurities and moisture from the incoming air. Its built-in temperature and humidity sensor monitors in real time and automatically controls heating to remove moisture from the desiccant.

[0011] This invention provides the following technical solution: a transformer maintenance-free dehumidifier, including a control box. A bracket is bolted to one side of the control box. A mounting block for a fixed induction head and a second cable outlet are provided on the outer side of the bracket. One end of a fixing frame is connected to the inner side of the bracket. Several heating element fixing frames are provided on the fixing frame, and corresponding heating elements are fixed on the heating element fixing frames. An outer filter screen is fitted onto the outer side of the fixing frame, and a glass cover is fitted onto the outer side of the outer filter screen. The other end of the fixing frame is connected to an outer filter screen flange. The outer filter screen flange is connected to an outer filter screen blocking plate. The outer filter screen blocking plate is connected to a rear seat. A circular... The circular opening has an outer ring welded along its circumference. A second filter screen is provided inside the outer ring, and a first filter screen is connected to the inner side of the second filter screen. A filter tube is embedded in the inner circumference of the second filter screen. A heating ring is sleeved on the outer side of the outer ring and is fixed to the rear seat by a pressure plate. The rear seat is connected to a rear cover plate by bolts. The filter tube passes through the middle of the rear cover plate, and a first wire outlet is also provided on the rear cover plate. The heating ring connecting wire is connected to the circuit board through the first wire outlet and a first interface. The glass cover and the outer filter screen are placed between the bracket and the rear seat, and the inner side of the outer filter screen is filled with desiccant.

[0012] The control box contains a circuit board, a pressure sensor, and a power supply. The top of the control box has a connection interface, a third interface, a second interface, and a first interface. The side of the control box has a power port, a first communication port, and a second communication port.

[0013] The sensor head mounting block is equipped with a temperature and humidity sensor inside. The sensor head mounting block is equipped with a crimping head, a flange joint, and a third outlet on its outer side. The crimping head is connected to a pressure sensor via a connection port. The temperature and humidity sensor is connected to a circuit board via a third outlet and a third interface. The heating element is connected to a circuit board via a second outlet and a second interface. The flange joint is used to connect to the transformer oil conservator bladder.

[0014] Preferably, the control box is also equipped with a waterproof connector, a self-reset switch, and a debugging interface.

[0015] Preferably, the control box is also equipped with a power indicator light, a fault indicator light, and a heating indicator light.

[0016] Preferably, the bracket is further provided with a PTFE pad on the inner side, and a fixing bracket is fixedly installed on the PTFE pad. The inner side of the outer circumference of the PTFE pad is also provided with a groove for accommodating the outer filter screen. The bracket is provided with a groove for accommodating the glass cover on the inner side. A sealing rubber ring is also provided in the groove for accommodating the glass cover. The rear seat is provided with grooves for accommodating the outer filter screen and the glass cover respectively on the inner side. A sealing rubber ring is provided in the groove.

[0017] Preferably, the fixing frame further includes a top plate and a bottom plate welded on both sides. The bottom plate is used to connect the bracket, and the top plate is used to connect the outer filter flange. The fixing frame is composed of three independent accommodating spaces, each accommodating space is equipped with a heating element, and one of the accommodating spaces is equipped with an inner temperature and humidity sleeve. An inner temperature and humidity sensor is installed inside the inner temperature and humidity sleeve. The inner temperature and humidity sensor and the heating element are connected in parallel by wires and connected to the circuit board through a second outlet and a second interface.

[0018] Preferably, the bracket is provided with mounting ears on both sides, and the mounting ears are provided with mounting holes.

[0019] Preferably, the bracket is also provided with a grounding terminal on its outer side.

[0020] Preferably, the heating element is a semiconductor ceramic heating element.

[0021] Preferably, the outer filter screen is made of stainless steel 304.

[0022] The control method for a transformer maintenance-free dehumidifier involves the following steps:

[0023] (1) The system performs a self-test upon startup and continuously monitors internal temperature and humidity, external temperature and humidity, and pressure.

[0024] (2) Determine whether the temperature is lower than the set threshold temperature. If yes, control the heating element and heating ring to heat. Otherwise, return to step (1).

[0025] (3) Determine whether the humidity exceeds the set threshold humidity;

[0026] (4) If yes, calculate the heating power based on the current humidity, the pressure is positive, start heating, update the indicator light display, and determine whether the humidity is lower than the standard humidity. If yes, return to step (3); otherwise, return to step (4).

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] This invention discloses a maintenance-free dehumidifier for transformers, which is a purification device specifically designed for transformers. Its main function is to remove and dry impurities and moisture from the air that enters the transformer oil conservator due to changes in transformer oil temperature. At the same time, it realizes automated monitoring and maintenance, which greatly improves the operating efficiency and safety of transformers.

[0029] The control box, as the core control unit of the dehumidifier, houses key components such as circuit boards, pressure sensors, and power supplies. Multiple interfaces are located on the top and side of the control box for connecting sensors, heating elements, and external communication and power sources. A bracket, bolted to one side of the control box, supports and secures other components. The bracket includes a sensor mounting block and a second cable outlet for installing temperature and humidity sensors and leading out heating element wires. Multiple heating element mounting brackets are located on the mounting frame for installing heating elements. The heating elements are connected to the circuit board inside the control box via wires to remove moisture from the desiccant. An outer filter is covered with... The glass cover forms a relatively enclosed space. The inner side of the outer filter screen is filled with desiccant to absorb moisture from the air. A circular opening is provided in the middle of the rear seat, and an outer ring is welded around the opening. The inner side of the outer ring is provided with a second filter screen and a first filter screen, as well as an embedded filter tube, forming a multi-filtration system. The outer filter screen plug plate is connected to the rear seat to further reinforce the structure. The heating ring is sleeved on the outer side of the outer ring and fixed to the rear seat by a pressure plate. The heating ring is used for further heating to improve dehumidification efficiency. The rear cover plate is connected to the rear seat by bolts, with the filter tube passing through the middle. The rear cover plate is provided with a first outlet for leading out the wire of the heating ring.

[0030] This device primarily functions as a "breathing" mechanism for the transformer's oil conservator. When the pressure difference between the inside and outside of the transformer changes, air enters the transformer through the outer filter and desiccant. The outer filter and desiccant work together to remove impurities and moisture from the air, ensuring that the incoming air is dry. The dehumidifier is connected to the oil tank and, through this "breathing" action, facilitates the exchange of air between the inside and outside of the system. It also filters moisture and impurities from the external air. Its built-in temperature and humidity sensors monitor the humidity inside the dehumidifier in real time. When the humidity exceeds the set value, the desiccant is dried by the heating element installed in the drying chamber. The water vapor generated during the drying process diffuses outwards through convection, passes through the metal mesh to the glass tube, and condenses on the glass tube. The condensed water droplets flow along the glass tube to the filter tube installed at the bottom and then out of the dehumidifier. The communication interface in the control box can also be connected to an external monitoring system to achieve remote monitoring and alarm functions. When the equipment malfunctions or experiences abnormal conditions, it can promptly issue an alarm and notify relevant personnel for handling.

[0031] Furthermore, this dehumidifier features a maintenance-free design, reducing the frequency and difficulty of manual maintenance. Its built-in temperature and humidity sensors and automatic heating system monitor and control the equipment's status in real time, ensuring long-term stable operation. Although designed to be maintenance-free, replacing parts is still very convenient when necessary. For example, when the desiccant becomes ineffective, simply opening the glass cover allows for easy replacement.

[0032] In summary, this transformer maintenance-free dehumidifier integrates advanced temperature and humidity monitoring, automatic heating control, and multiple filtration technologies to effectively remove and dehumidify the air entering the transformer. Its maintenance-free design and easy-to-replace components also greatly improve the reliability and ease of maintenance of the equipment. Attached Figure Description

[0033] Figure 1 This is a three-dimensional structural diagram of a specific embodiment of the present invention;

[0034] Figure 2 for Figure 1 Another structural schematic diagram of the specific implementation method shown;

[0035] Figure 3 for Figure 1 Exploded view of the specific implementation method shown;

[0036] Figure 4 This is a schematic diagram of the fixed frame structure;

[0037] Figure 5 for Figure 4 Another structural diagram;

[0038] Figure 6 This is a flowchart of the control method.

[0039] Explanation of reference numerals in the attached figures:

[0040] 1. Control box; 2. Bracket; 3. Glass cover; 4. Outer filter; 5. Mounting bracket; 6. Heating element;

[0041] 7. Heating element mounting bracket; 8. Internal temperature and humidity sensor; 9. Internal temperature and humidity sleeve; 10. Top plate; 11. Bottom plate; 12. Outer filter flange; 13. Outer filter plug; 14. Rear seat; 15. Flange joint; 16. Third cable outlet; 17. Pressure plate; 18. Heating ring; 19. Second filter; 20. First filter; 21. Rear cover; 22. Filter tube; 23. First cable outlet; 24. PTFE gasket; 25. Grounding terminal; 26. Sensor head mounting block; 27. Crimp straight head; 28. Second cable outlet;

[0042] 1-1. Circuit board; 1-2. Pressure sensor; 1-3. Power indicator light; 1-4. Fault indicator light;

[0043] 1-5 Heating indicator light; 1-6 Waterproof connector; 1-7 Self-reset switch; 1-8 Debugging interface; 1-9 Power port; 1-10 First communication port; 1-11 Second communication port; 1-12 Connection port; 1-13 Third interface; 1-14 Second interface; 1-15 First interface. Detailed Implementation

[0044] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0045] like Figures 1-6 As shown, it illustrates a specific embodiment of the present invention: as Figures 1-6As shown, the transformer maintenance-free dehumidifier disclosed in this invention includes a control box 1. A bracket 2 is bolted to one side of the control box 1. A fixed sensor head mounting block 26 and a second cable outlet 28 are provided on the outer side of the bracket 2. One end of a fixing frame 5 is connected to the inner side of the bracket 2. Several heating element fixing frames 7 are provided on the fixing frame 5, and corresponding heating elements 6 are fixed on the heating element fixing frames 7. An outer filter screen 4 is sleeved on the outer side of the fixing frame 5, and a glass cover 3 is sleeved on the outer side of the outer filter screen 4. The other end of the fixing frame 5 is connected to an outer filter screen flange 12. The outer filter screen flange 12 is connected to an outer filter screen blocking plate 13. The outer filter screen blocking plate 13 is connected to a rear seat 14. A circular opening is provided in the middle of the rear seat 14. An annular outer edge is welded along the circumference. A second filter screen 19 is provided on the inner side of the annular outer edge. A first filter screen 20 is connected to the inner side of the second filter screen 19. A filter tube 22 is embedded in the inner circumference of the second filter screen 19. A heating ring 18 is sleeved on the outer side of the annular outer edge. The heating ring 18 is fixed to the rear seat 14 by a pressure plate 17. The rear seat 14 is connected to a rear cover plate 21 by bolts. The filter tube 22 passes through the middle of the rear cover plate 21. A first wire outlet 23 is also provided on the rear cover plate 21. The heating ring 18 is connected to a wire and connected to a circuit board 1-1 through the first wire outlet 23 and the first interface 1-15. The glass cover 3 and the outer filter screen 4 are arranged between the bracket 2 and the rear seat 14. The inner side of the outer filter screen 4 is filled with desiccant.

[0046] The control box 1 contains a circuit board 1-1, a pressure sensor 1-2, and a power supply. The top of the control box 1 is provided with a connection interface, a third interface 1-13, a second interface 1-14, and a first interface 1-15. The side of the control box 1 is provided with a power port 1-9, a first communication port 1-10, and a second communication port 1-11.

[0047] A temperature and humidity sensor is installed inside the sensor head mounting block 26. A crimping straight head 27, a flange joint 15, and a third outlet 16 are respectively installed on the outside of the sensor head mounting block 26. The crimping straight head 27 is connected to the pressure sensor 1-2 through the connection port 1-12. The temperature and humidity sensor is connected to the circuit board 1-1 through the third outlet 16 and the third interface 1-13. The heating element 6 is connected to the circuit board 1-1 through the second outlet 28 and the second interface 1-14. The flange joint 15 is used to connect the transformer oil conservator capsule.

[0048] This invention features a multi-layered filtration structure, including a glass cover, outer filter flange, outer filter, outer filter blockage plate, first filter, and filter tube. During the transformer's breathing process, impurities and moisture in the air are filtered out to prevent them from entering the transformer and affecting the insulation strength of the transformer oil. The heating element in this invention is mounted on a fixed frame, inside the outer filter, to keep the desiccant dry. Since the desiccant becomes saturated after absorbing a certain amount of moisture, it needs to be replaced manually periodically. This not only increases the workload of maintenance but may also lead to a decrease in moisture absorption efficiency if replacement is not timely. Therefore, the heating element designed in this invention is to heat the desiccant, eliminating the need for replacement and achieving a maintenance-free effect. It is also used in conjunction with components such as a heating ring to further regulate its humidity and temperature.

[0049] The components inside and on the control box, especially the power port, first communication port, and second communication port on the control box, are designed to ensure the normal operation of the device. The communication interface inside the control box can be connected to an external monitoring system to realize remote monitoring and alarm functions. When the equipment malfunctions or abnormalities, it can promptly issue an alarm and notify relevant personnel for handling.

[0050] Preferred, such as Figure 2 As shown, the control box 1 is also equipped with a waterproof connector 1-6, a self-reset switch 1-7, and a debugging interface 1-8.

[0051] The main function of the waterproof connectors 1-6 on the control box 1 is to ensure that the internal electronic components of the control box 1 are protected from moisture while allowing air circulation or the connection of certain cables. This is especially important for the control box 1, which needs to be used in a humid environment, as it can effectively prevent condensation inside, improve the stability and service life of the equipment. The self-reset switches 1-7 are mainly used for emergency shutdown, fault reset, or restart of the equipment. In case of any abnormal situation, the user can restore the equipment to normal working condition by pressing the self-reset switches 1-7.

[0052] Debugging interfaces 1-8 (configured as 4-pin connectors) are used to connect debugging equipment, allowing technicians to monitor, debug, and program the internal circuitry without opening the control box 1 casing. During debugging, technicians use dedicated debugging cables to connect the debugging equipment to debugging interfaces 1-8, and then use specific software or hardware tools to configure, test, and troubleshoot the internal circuitry of control box 1. The inclusion of debugging interfaces 1-8 significantly improves the maintainability and flexibility of the equipment.

[0053] In summary, the waterproof connectors 1-6, self-reset switches 1-7, and debugging interfaces 1-8 on control box 1 each perform different functional roles, together constituting the complete functional system of control box 1. These designs enable control box 1 to adapt to various complex operating environments, improving the reliability and ease of use of the equipment.

[0054] Preferred, such as Figure 1 As shown, the control box 1 is also equipped with a power indicator light 1-3, a fault indicator light 1-4 and a heating indicator light 1-5.

[0055] The power indicator light 1-3, fault indicator light 1-4 and heating indicator light 1-5 set on the control box 1 each play an important role in displaying different working states of the device.

[0056] Power indicator lights 1-3: These indicate the power status of control box 1 or the device. They are typically designed to be green and will illuminate when power is supplied normally. If the light is off, it may indicate that power is not supplied or there is a malfunction. Power indicator lights 1-3 are crucial signals for determining whether the device is ready for operation and are essential for ensuring safe startup and operation of the equipment.

[0057] Fault Indicator Lights 1-4: These lights indicate whether the device has malfunctioned. They are typically red and will illuminate immediately when a malfunction occurs, such as a power failure, communication failure, or damage to internal components. The illumination of Fault Indicator Lights 1-4 is an important reminder for operators to promptly troubleshoot and resolve the fault, helping to prevent further deterioration and ensuring the safe operation of the equipment.

[0058] Heating indicator lights 1-5: These lights indicate the heating status of the device. The light illuminates when the device begins heating; it may turn off when heating stops or the preset temperature is reached. Heating indicator lights 1-5 are crucial for monitoring and controlling the heating process, helping to ensure the accuracy and safety of heating operations.

[0059] By installing these indicator lights on control box 1, a complete status display system can be formed, enabling operators to quickly understand the operating status of the equipment and promptly identify and address potential problems. This helps improve the reliability and safety of the equipment, and reduces the failure rate and maintenance costs. At the same time, these indicator lights also provide important reference information for the daily maintenance and troubleshooting of the equipment.

[0060] In summary, the placement of power indicator lights 1-3, fault indicator lights 1-4, and heating indicator lights 1-5 on control box 1 together constitutes an important part of the device status display, which is of great significance for ensuring the normal operation and safe use of the equipment.

[0061] Preferred, such as Figure 3As shown, the bracket 2 is also provided with a PTFE pad 24 on its inner side, and a fixing bracket 5 is fixedly installed on the PTFE pad 24. The outer circumference of the PTFE pad 24 is also provided with a groove for accommodating the outer filter screen 4. The bracket 2 is provided with a groove for accommodating the glass cover 3 on its inner side. A sealing rubber ring is also provided in the groove for accommodating the glass cover 3. The rear seat 14 is provided with grooves for accommodating the outer filter screen 4 and the glass cover 3 on its inner side, and a sealing rubber ring is provided in the groove.

[0062] The PTFE gasket 24 is cleverly positioned inside the bracket 2, playing multiple crucial roles, especially in sealing and insulation. Due to its excellent chemical stability and corrosion resistance, the PTFE gasket 24 effectively prevents leakage of various fluids or gases through the contact surface. The PTFE gasket 24, positioned inside the bracket 2, can tightly fit surrounding components such as the mounting bracket 5, the outer filter 4, and the glass cover 3, ensuring the overall structure's airtightness.

[0063] By fixing the mounting bracket 5 onto the PTFE pad 24, the PTFE pad 24 not only provides stable support, but also helps to alleviate the loosening or deformation of components that may be caused by temperature changes or mechanical stress through its elastic properties, thereby further enhancing the sealing and stability of the entire structure.

[0064] Sealing rubber rings are installed in the grooves of the glass cover 3 and the inner groove of the rear seat 14. These rubber rings, together with the PTFE gasket 24, form a multi-layered sealing system, which greatly improves the sealing effect and prevents any possible leakage.

[0065] Meanwhile, PTFE has a low thermal conductivity. When used as an insulation layer, PTFE can effectively slow down the rate of heat transfer, thus achieving a good insulation effect. This means that it can effectively prevent heat transfer and insulate the internal heating components (heating plates). By reducing heat loss, the PTFE insulation layer can ensure that more of the heat generated by the heating components is used to heat and remove moisture from the desiccant, thereby effectively removing and dehumidifying the air entering the transformer. This not only improves heating efficiency but also enhances dehumidification.

[0066] Preferred, such as Figures 3-5 As shown, the fixing frame 5 also includes a top plate 10 and a bottom plate 11 welded on both sides. The bottom plate 11 is used to connect the bracket 2, and the top plate 10 is used to connect the outer filter flange 12. The fixing frame 5 forms three independent accommodating spaces. Each accommodating space is equipped with a heating element 6. One of the accommodating spaces is equipped with an inner temperature and humidity sleeve 9. An inner temperature and humidity sensor 8 is installed inside the inner temperature and humidity sleeve 9. The inner temperature and humidity sensor 8 and the heating element 6 are connected in parallel by wires and connected to the circuit board 1-1 through the second outlet 28 and the second interface 1-14.

[0067] The mounting frame 5 consists of a top plate 10 and a bottom plate 11 welded to both sides. The bottom plate 11 connects to the support 2, ensuring the stability and positional accuracy of the mounting frame 5. The top plate 10 connects to the outer filter flange 12, achieving a reliable connection between the mounting frame 5 and the external structure. The mounting frame 5 has three independent accommodating spaces, each equipped with a heating element 6. This design ensures more uniform heating. One of the accommodating spaces contains an inner temperature and humidity sleeve 9, inside which is installed an inner temperature and humidity sensor 8. The inner temperature and humidity sensor 8 can monitor the temperature and humidity changes of a specific space inside the mounting frame 5 in real time and accurately. Because the sensor is installed inside the protected sleeve, its readings are more stable and reliable, and can more accurately reflect the actual internal environment.

[0068] The internal temperature and humidity sensor 8 is connected in parallel with the heating element 6 via a wire, and then connected to the circuit board 1-1 through the second output port 28 and the second interface 1-14. This connection method ensures reliable transmission of sensor signals and heating control signals, enabling the circuit board to precisely control the heating element 6 based on the real-time readings of the sensor. After receiving the readings from the internal temperature and humidity sensor 8, the circuit board 1-1 calculates the required heating power according to a preset heating control algorithm and achieves precise heating control by controlling the energization state of the heating element 6. Because the sensor can accurately reflect changes in the internal temperature and humidity, the heating control is more precise and timely.

[0069] In summary, the mounting bracket 5 is connected to the connecting support 2 and the outer filter flange 12 via its base plate 11 and top plate 10, respectively, thus forming a connecting device for the transformer oil conservator capsule. This enables the transformer oil conservator to breathe, effectively removing and dehumidifying the air entering the transformer. Its working principle is that when the pressure difference between the inside and outside of the transformer changes, air enters the transformer through the outer filter 4 and desiccant. The outer filter 4 and desiccant work together to remove impurities and moisture from the air, ensuring that the incoming air is dry. The dehumidifier is connected to the oil conservator, and through this breathing effect, the exchange of air between the inside and outside of the system is achieved. The dehumidifier not only filters moisture and impurities from the outside air, but also utilizes a built-in temperature and humidity sensor to monitor the humidity inside the dehumidifier in real time. When the humidity exceeds a set value, the desiccant is dried by the heating element installed in the drying chamber. The water vapor generated during the drying process diffuses outwards through convection, passes through the metal mesh to the glass tube, and condenses on the glass tube. The condensed water droplets flow along the glass tube to the filter tube 22 installed at the bottom and then out of the dehumidifier. Therefore, because the fixed frame 5 is equipped with a built-in temperature and humidity sensor, the control system can accurately control the working status of the heating element based on real-time humidity data. When the humidity is high, the heating element will work at a higher power to quickly remove moisture; when the humidity drops to a certain level, the heating element will reduce its power or stop working to avoid over-drying and energy waste. This precise control method not only improves the dehumidification efficiency of the equipment, but also extends the service life of the desiccant. The design and working principle of the fixed frame 5 and its related components together constitute a highly efficient and stable transformer oil conservator breathing and dehumidification system. This system can not only effectively remove and dry the air that enters the transformer, but also enable remote monitoring and alarm functions, providing a strong guarantee for the safe operation of the transformer.

[0070] Preferred, such as Figures 1-3 As shown, the bracket 2 is also provided with mounting ears on both sides, and mounting holes are provided on the mounting ears.

[0071] Mounting ears are an additional structure on bracket 2. Their main function is to provide a reliable connection point, allowing bracket 2 to be connected to other components or structures via fasteners such as bolts and nuts.

[0072] The location, number, and size of the mounting holes are determined according to specific connection requirements to ensure the stability and reliability of the connection. This device is connected to the transformer oil tank capsule through flange joint 15, thereby achieving communication with the transformer oil tank. During installation, this device is designed with two mounting holes, which can be further fixed through mounting ears and mounting holes.

[0073] In summary, the mounting ears and mounting holes on both sides of the bracket 2 provide convenience and reliability for connecting the bracket 2 with other components or structures.

[0074] Preferred, such as Figures 1-2 As shown, a grounding terminal 25 is also provided on the outside of the bracket 2.

[0075] Setting a grounding terminal 25 on the outside of the bracket 2 is an important safety protection measure, designed to ensure the safe operation of the equipment under electrical faults.

[0076] Grounding terminal 25 is mainly used to connect the grounding wire, making a reliable electrical connection between the metal casing, frame, and other parts of the equipment or system and the earth. This connection ensures that in the event of an electrical fault, such as equipment leakage or short circuit, the current can quickly flow into the earth through the grounding device, thereby preventing the current from causing harm to the human body or damage to the equipment.

[0077] A grounding terminal 25 is provided on the outside of the bracket 2, which allows the bracket 2 to be easily connected to the grounding system. This connection is crucial for ensuring the electrical safety of the entire equipment or system.

[0078] In summary, the installation of a grounding terminal 25 on the outside of the bracket 2 is an important safety protection measure, ensuring the safe operation of the equipment under severe weather conditions such as electrical faults or lightning strikes. Therefore, the installation and connection requirements of the grounding terminal 25 should be fully considered during the design and installation of the equipment to ensure the electrical safety of the entire equipment or system.

[0079] Preferably, the heating element 6 is a semiconductor ceramic heating element 6.

[0080] Heating element 6 uses a semiconductor ceramic heating element. The working principle of the semiconductor ceramic heating element is based on the principle of resistance heating, that is, when current passes through the material, heat is generated due to resistance loss. Semiconductor ceramic materials have high resistivity, which allows more heat to be generated when current passes through them. At the same time, semiconductor ceramic materials have high thermal conversion efficiency, which can efficiently convert electrical energy into heat energy.

[0081] It has the following advantages:

[0082] High efficiency and energy saving: Semiconductor ceramic heating elements can quickly convert electrical energy into heat energy, achieving efficient heating. Compared with traditional heating equipment, it has a higher energy utilization rate and can significantly reduce energy consumption.

[0083] Uniform heating: Semiconductor ceramic heating elements enable uniform heating, avoiding problems such as localized overheating and insufficient heating that occur in traditional heating equipment. This helps extend the service life of the equipment and improve heating efficiency.

[0084] Safe and environmentally friendly: Semiconductor ceramic heating elements do not produce waste gas or wastewater during operation, making them environmentally friendly. Furthermore, their automatic temperature regulation feature allows the equipment to automatically shut off power in case of overheating, enhancing safety.

[0085] Long lifespan: Semiconductor ceramic materials have high corrosion resistance and high temperature stability, which gives the heating element a long service life.

[0086] Adjustability: Semiconductor ceramic heating elements can adjust the heating power by controlling the current, thereby meeting different heating needs. This adjustability allows the equipment to maintain efficient and stable performance in various application scenarios.

[0087] In summary, semiconductor ceramic heating elements are preferred for this device due to their advantages such as high efficiency and energy saving, uniform heating, safety and environmental protection, long life and adjustability.

[0088] Preferably, the outer filter 4 is made of stainless steel 304.

[0089] The outer filter 4 is made of 304 stainless steel and has been polished. This design choice fully considers the usage environment and functional requirements of the device.

[0090] Since this device is used for dehumidification and is in a humid environment for a long time, the use of 304 stainless steel, which has excellent corrosion resistance, can ensure the stability and reliability of the device during long-term operation. The use of 304 stainless steel can also ensure that the filter screen is not easily deformed, damaged or rusted during long-term operation, thereby ensuring its filtration effect and service life.

[0091] In conclusion, the selection of 304 stainless steel for the outer filter 4, with its polished finish, is a reasonable choice based on the operating environment and functional requirements of the device. This design choice ensures the stability and reliability of the device during long-term operation, while also enhancing the overall quality and aesthetics of the device.

[0092] like Figure 6 As shown, the control method for the transformer maintenance-free dehumidifier involves the following steps:

[0093] (1) The system performs a self-test upon startup and continuously monitors internal temperature and humidity, external temperature and humidity, and pressure.

[0094] (2) Determine whether the temperature is lower than the set threshold temperature. If yes, control the heating element 6 and heating ring 18 to heat. Otherwise, return to step (1).

[0095] (3) Determine whether the humidity exceeds the set threshold humidity;

[0096] (4) If yes, calculate the heating power based on the current humidity, the pressure is positive, start heating, update the indicator light display, and determine whether the humidity is lower than the standard humidity. If yes, return to step (3); otherwise, return to step (4).

[0097] In summary, through precise temperature, humidity, and pressure monitoring, as well as intelligent heating control strategies, the dehumidifier can efficiently dehumidify and maintain a dry environment inside the transformer.

[0098] This invention aims to maintain three parameters within the maintenance-free dehumidifier: pressure, temperature, and humidity. Therefore, temperature and humidity must be assessed separately. When the internal pressure is positive, a relatively closed environment is created, preventing the entry of external humid air. If external humid air enters the system, it increases the internal humidity, hindering humidity control. By maintaining a positive pressure differential and applying heat, the entry of external humid air can be prevented, thus ensuring the dryness of the transformer oil.

[0099] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. These changes involve related technologies well known to those skilled in the art, and all of them fall within the protection scope of the present invention.

[0100] Many other changes and modifications can be made without departing from the concept and scope of this invention. It should be understood that this invention is not limited to the specific embodiments, and the scope of this invention is defined by the appended claims.

Claims

1. A maintenance-free dehumidifier for transformers, characterized in that, The system includes a control box (1), one side of which is bolted to a bracket (2). A fixed sensor head mounting block (26) and a second cable outlet (28) are provided on the outer side of the bracket (2). One end of a fixing frame (5) is connected to the inner side of the bracket (2). Several heating element fixing frames (7) are provided on the fixing frame (5). A corresponding heating element (6) is fixed on the heating element fixing frame (7). An outer filter screen (4) is fitted on the outer side of the fixing frame (5). A glass cover (3) is fitted on the outer side of the outer filter screen (4). The other end of the fixing frame (5) is connected to an outer filter screen flange (12). The outer filter screen flange (12) is connected to an outer filter screen blocking plate (13). The outer filter screen blocking plate (13) is connected to a rear seat (14). A circular opening is provided in the middle of the rear seat (14). An annular outer edge is welded along the circumference of the circular opening. A second filter screen (19) is provided on the inner side of the outer edge of the ring. The inner side of the second filter screen (19) is connected to the first filter screen (20). A filter tube (22) is embedded in the inner circumference of the second filter screen (19). A heating ring (18) is sleeved on the outer side of the outer edge of the ring. The heating ring (18) is fixed on the rear seat (14) by a pressure plate (17). The rear seat (14) is connected to the rear cover plate (21) by bolts. The filter tube (22) passes through the middle of the rear cover plate (21). The rear cover plate (21) is also provided with a first outlet (23). The heating ring (18) is connected to the circuit board (1-1) through the first outlet (23) and the first interface (1-15). The glass cover (3) and the outer filter screen (4) are arranged between the bracket (2) and the rear seat (14). The inner side of the outer filter screen (4) is filled with desiccant. The control box (1) is equipped with a circuit board (1-1), a pressure sensor (1-2), and a power supply. The top of the control box (1) is equipped with a connection interface, a third interface (1-13), a second interface (1-14), and a first interface (1-15). The side of the control box (1) is equipped with a power port (1-9), a first communication port (1-10), and a second communication port (1-11). The sensor head mounting block (26) is equipped with a temperature and humidity sensor inside. The sensor head mounting block (26) is equipped with a crimping head (27), a flange joint (15), and a third outlet (16) on the outside. The crimping head (27) is connected to a pressure sensor (1-2) through a connection port (1-12). The temperature and humidity sensor is connected to a circuit board (1-1) through a third outlet (16) and a third interface (1-13). The heating element (6) is connected to a circuit board (1-1) through a second outlet (28) and a second interface (1-14). The flange joint (15) is used to connect to the transformer oil conservator capsule.

2. The transformer maintenance-free dehumidifier according to claim 1, characterized in that, The control box (1) is also equipped with a waterproof connector (1-6), a self-reset switch (1-7), and a debugging interface (1-8).

3. The transformer maintenance-free dehumidifier according to claim 2, characterized in that, The control box (1) is also equipped with a power indicator light (1-3), a fault indicator light (1-4), and a heating indicator light (1-5).

4. The transformer maintenance-free dehumidifier according to claim 3, characterized in that, The bracket (2) is also provided with a PTFE pad (24) on the inner side. A fixing bracket (5) is fixedly installed on the PTFE pad (24). The outer circumference of the PTFE pad (24) is also provided with a groove for accommodating the outer filter screen (4). The bracket (2) is provided with a groove for accommodating the glass cover (3) on the inner side. A sealing rubber ring is also provided in the groove for accommodating the glass cover (3). The rear seat (14) is provided with grooves for accommodating the outer filter screen (4) and the glass cover (3) on the inner side. A sealing rubber ring is provided in the groove.

5. The transformer maintenance-free dehumidifier according to any one of claims 1-4, characterized in that, The fixing frame (5) also includes a top plate (10) and a bottom plate (11) welded on both sides. The bottom plate (11) is used to connect the bracket (2), and the top plate (10) is used to connect the outer filter flange (12). The fixing frame (5) forms three independent accommodating spaces. Each accommodating space is equipped with a heating element (6). One of the accommodating spaces is equipped with an inner temperature and humidity sleeve (9). An inner temperature and humidity sensor (8) is installed inside the inner temperature and humidity sleeve (9). The inner temperature and humidity sensor (8) and the heating element (6) are connected in parallel by wires and connected to the circuit board (1-1) through the second outlet (28) and the second interface (1-14).

6. The transformer maintenance-free dehumidifier according to claim 5, characterized in that, The bracket (2) is also provided with mounting ears on both sides, and mounting holes are provided on the mounting ears.

7. The transformer maintenance-free dehumidifier according to claim 6, characterized in that, The bracket (2) is also provided with a grounding terminal (25) on its outer side.

8. The transformer maintenance-free dehumidifier according to claim 7, characterized in that, The heating element (6) is a semiconductor ceramic heating element (6).

9. The transformer maintenance-free dehumidifier according to claim 8, characterized in that, The outer filter (4) is made of stainless steel 304.

10. A control method for a transformer maintenance-free dehumidifier, characterized in that, Using the transformer maintenance-free dehumidifier as described in any one of claims 1-9, the following steps are performed: (1) The system performs a self-test upon startup and continuously monitors internal temperature and humidity, external temperature and humidity, and pressure. (2) Determine whether the temperature is lower than the set threshold temperature. If yes, control the heating element (6) and heating ring (18) to heat. Otherwise, return to step (1). (3) Determine whether the humidity exceeds the set threshold humidity; (4) If yes, calculate the heating power based on the current humidity, the pressure is positive, start heating, update the indicator light display, and determine whether the humidity is lower than the standard humidity. If yes, return to step (3); otherwise, return to step (4).

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