Energy-saving and environment-friendly dry-type power transformer

Abstract

The invention relates to the technical field of transformers, and discloses an energy-saving and environment-friendly dry-type power transformer which comprises a support for supporting a transformer body, the support is C-shaped and symmetrically installed on the two sides of the upper end and the lower end of the transformer, and a sheath is installed at the joint of the outer side of the transformer and the support. The upper end and the lower end of the sheath are in butt joint with the air channel in the center inside the support. High-temperature hot air enters the air cylinder from the lower portion of the air cylinder, in the air cylinder, due to the fact that the hot air rises continuously, an ascending air flow is formed, cold air enters the top of the air cylinder through the air channel above the support, steady-state convection is formed, and due to the fact that the cold air and the hot air move and interact in the air cylinder, the vortex phenomenon can be generated, and the heat dissipation efficiency is improved. And the transformer is further naturally cooled, so that the beneficial effect of improving the natural wind power efficiency of the dry-type transformer is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of transformers, in particular to an energy-saving and environment-friendly dry-type power transformer. Background Art

[0002] Dry-type power transformer is a common power equipment. Unlike oil-immersed transformer, dry-type transformer does not use liquid: oil, as insulation and cooling medium, but solid insulation material. Dry-type transformer uses solid insulation material, such as epoxy resin, glass fiber reinforced plastic (FRP), etc., to insulate windings and provide structural support. It usually adopts natural air cooling (AN) or forced air cooling (AF). When natural air cooling, the transformer can operate continuously for a long time at rated capacity. When forced air cooling, the transformer output capacity can be increased by 50%. The winding is usually made of copper or aluminum and wrapped in solid insulation material. Since liquid insulation is not used, dry-type transformer is safer in terms of fire and environmental pollution.

[0003] However, since dry-type transformers rely on wind cooling, they can only rely on forced air cooling for cooling under peak conditions. However, forced air cooling also has a threshold, that is, in actual situations, the transformer temperature may rise but fail to meet the forced air cooling start-up conditions, and natural air cooling cannot meet the conditions, resulting in loss of transformer life. Summary of the invention

[0004] Technical issues solved:

[0005] In view of the deficiencies in the prior art, the present invention provides an energy-saving and environmentally friendly dry-type power transformer, which has the advantages of improving the natural wind efficiency of the dry-type transformer and being more energy-efficient when starting forced air cooling to cool the transformer, thereby solving the problems of the above-mentioned technology.

[0006] Technical solution:

[0007] To achieve the above-mentioned object, the present invention provides the following technical solutions: an energy-saving and environment-friendly dry-type power transformer, comprising a bracket supporting a transformer body, the bracket being "C"-shaped and symmetrically installed on both sides of the upper and lower ends of the transformer, a sheath being installed at the connection between the outer side of the transformer and the bracket, and the upper and lower ends of the sheath being butt-jointed to an air duct arranged at the center part of the inner side of the bracket;

[0008] The air duct is formed by the rear walls of two brackets close to each other, and is used to guide natural wind into the sheath to cool the transformer. The wind guide plate arranged in the air duct guides the wind from the air duct into the sheath and makes the wind contact the transformer for cooling, and finally guides the wind from the air duct under the sheath to contact the wind turbine structure installed at the rear end of the bracket. The wind turbine structure is used to mix the hot air that has passed through the transformer with the cold air that has not passed through the transformer to form an air vortex, thereby accelerating the extraction of hot air from the transformer;

[0009] The wind turbine structure includes a wind tube installed at the tail ends of two brackets. The front and rear ends of the wind tube are through-connected with the two brackets and the connection is sealed. A vertically upward guide rod is installed on the inner bottom surface of the wind tube, and the top of the guide rod is connected to an electric fan blade.

[0010] Preferably, an air guide plate is installed inside the air duct, and the air guide plate is a curved cover with a bottom inclined downward.

[0011] Preferably, a guide plate is installed at the bottom of the inner side of the air duct below the bracket, the bottom of the guide plate is connected to the inner bottom surface of the air duct, and the top is inclined upward to connect to the inner side of the air duct, so as to deliver hot air into the air duct, and the inclination angle of the guide plate is between 15°-45°.

[0012] Preferably, the inner side of the sheath is laterally connected to the transformer using a support rod, the front end of the support rod is bolted to the inner wall of the sheath and the rear end is bolted to the side wall of the transformer, the support rod is a copper-aluminum alloy, the sheath is fixedly connected to the transformer through the support rod, and a gap of the length of the support rod is formed between the sheath and the transformer to accommodate the passage of cold air, so that the cold air contacts the transformer for cooling.

[0013] Preferably, the wind force distribution of the wind in the air duct after passing through the guide plate is calculated as:

[0014] For each deflector inlet and outlet wind speed, calculate the initial wind force:

[0015]

[0016] Where: P total is the total wind force; ρ is the density of air, 1.225, kg / m 3 ; A is the cross-sectional area of ​​the air duct, unit: m 2 ; is the total wind speed before passing through all wind deflectors, unit: m / s;

[0017] Calculation of the influence of the guide plate

[0018]

[0019] in:

[0020] ΔP i is the pressure loss caused by the i-th guide plate, unit: Pa; K i is the loss coefficient related to the shape and angle of the i-th guide plate; V i is the wind speed before the i-th guide plate, unit: m / s;

[0021] Wind speed change calculation

[0022]

[0023] Where: V i+1 is the wind speed after the i+1th wind deflector, unit: m / s; V i is the wind speed before the i-th wind deflector, unit: m / s;

[0024] The total loss is calculated as:

[0025]

[0026] Where: ΔP total is the total pressure loss of the entire system, unit: Pa; n is the total number of air guide plates;

[0027] Wind loss calculation

[0028] P final =P total -ΔP total

[0029] ΔP loss =P total -P final

[0030] Where: P final The remaining wind force after passing through all wind deflectors, unit: W; ΔP loss is the total wind loss, unit: W.

[0031] Preferably, the wind force received by the wind tube is calculated as:

[0032]

[0033] Where: V n is the wind speed after the last wind deflector, unit: m / s; V1 is the initial wind speed at the air duct entrance, unit: m / s; is the proportion of wind speed loss caused by the i-th guide plate: dimensionless; n is the total number of guide plates.

[0034] Preferably, an air guide ring is installed on the top of the wind tube, the air guide ring is spirally bent and has a hollow center, and the top of the air guide ring is at the same height as the wind tube and the tail end of the air duct located on the top of the transformer.

[0035] Preferably, a through opening sealedly connected to the air duct is provided at one side of the bottom of the air duct, and a ventilating fan is installed inside the through opening. The air outlet of the ventilating fan faces the inside of the air duct and the rear is directly opposite to the inner center of the air duct.

[0036] Preferably, a closing structure is movably installed near the sleeve on the side wall of the bracket to close the gap between the sleeve and the outside world. The closing structure includes a closing plate made of rubber material. A sliding rail and a slider are arranged at the connection between the rear wall of the closing plate. The rear wall of the closing plate is also connected to a driving structure arranged in the "C"-shaped hollow part of the bracket.

[0037] Preferably, the driving structure includes a connecting rod with a front end hingedly connected to the rear wall of the closing plate and a rear end fixedly connected to a steering wheel arranged in the "C"-shaped hollow part of the bracket, the connecting rod is hinged to the slider, and a servo drive motor is installed inside the steering wheel, and the servo drive motor is used to drive the steering wheel to rotate and drive the connecting rod to swing.

[0038] Compared with the prior art, the present invention provides an energy-saving and environment-friendly dry-type power transformer, which has the following beneficial effects:

[0039] 1. The present invention forms an air duct through the rear wall of the support rod connected to the sheath. The head end and the top opening of the air duct are used to receive natural wind force. As the natural wind enters the air duct from the air, it is squeezed to form a canyon effect, thereby increasing the wind speed. Then the accelerated natural wind contacts the transformer inside the sheath. Since the air duct below the bracket also contacts the air at the same time, the air in the air duct below the bracket drives the hot air to move into the wind tube. At this time, the hot air with high temperature enters the wind tube from the bottom of the wind tube, and the remaining cold air in the air duct above the bracket enters the inner side of the wind tube from the top of the wind tube after the wind force is lost through multiple sheaths. At this time, the inside of the wind tube is There are hot and cold air at the same time, and the hot air rises and the cold air falls. Inside the wind duct, due to the continuous rise of hot air, an updraft is formed, and the cold air enters the top of the wind duct through the air duct above the bracket, forming a steady-state convection. Due to the movement and interaction of hot and cold air inside the wind duct, eddy currents will be generated. The rise of hot air and the fall of cold air not only promote the circulation of internal air, but also form an air vortex in the wind duct, thereby further extracting outside air. At this time, the outside air is input into the inside of the wind duct from the two air ducts, and further cools the transformer naturally, achieving the beneficial effect of improving the natural wind efficiency of the dry-type transformer.

[0040] 2. The present invention has a built-in single-chip microcomputer through a servo motor, and the single-chip microcomputer is connected with the electric fan blades and the guide fan wires. When the temperature of the transformer reaches the forced cooling threshold, the single-chip microcomputer starts the above equipment, and the guide fan is started and rotates rapidly to form a negative pressure area at the rear, so that the hot air in the air duct below the transformer is quickly introduced into the air duct, and the closing plate flips downward to cover the gap between the sheath and the outside world, so that only the air duct is retained as the air inlet. At this time, the electric fan blades on the inside of the air duct are started synchronously to transport the hot air upward faster to complete the intersection with the cold air. As the hot air continues to rise, an ascending airflow is formed, and the cold air enters the top of the air duct through the air duct above the bracket, forming a steady-state convection. Due to the movement and interaction of the hot and cold air inside the air duct, an air vortex is formed in the air duct, which further draws outside air. The vortex wind speed is higher than that under normal conditions, and the heat dissipation is faster, achieving the beneficial effect of more energy saving when starting forced air cooling to cool the transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0042] Figure 2 It is a front cross-sectional schematic diagram of the air duct structure of the present invention;

[0043] Figure 3 It is an enlarged schematic diagram of the guide plate structure of the present invention;

[0044] Figure 4 It is a schematic cross-sectional view of the sheath structure of the present invention;

[0045] Figure 5 It is an enlarged schematic diagram of the composite board structure of the present invention;

[0046] Figure 6 It is an enlarged schematic diagram of the connecting rod structure of the present invention;

[0047] Figure 7 It is an enlarged schematic diagram of the air guide plate structure of the present invention.

[0048] Among them: 1. transformer; 101. sheath; 102. support rod; 2. bracket; 3. air duct; 301. air guide plate; 302. guide plate; 4. air cylinder; 401. guide rod; 405. electric fan blade; 406. air guide ring; 407. opening; 408. air guide fan; 5. closing plate; 6. connecting rod. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] Embodiment 1

[0051] See also Figure 1-7 , an energy-saving and environmentally friendly dry-type power transformer, comprising a bracket 2 supporting a transformer 1 body, the bracket 2 being "C"-shaped and symmetrically mounted on both sides of the upper and lower ends of the transformer, a sheath 101 being mounted at the connection between the outer side of the transformer 1 and the bracket 2, and the upper and lower ends of the sheath 101 being butt-jointed to an air duct 3 disposed at the inner center portion of the bracket 2;

[0052] The air duct 3 is formed by the rear wall of the two brackets 2 close to each other, and is used to guide natural wind into the sheath 101 to cool the transformer. The wind guide plate 301 arranged in the air duct 3 guides the wind from the air duct 3 into the sheath 101 and makes the wind contact the transformer 1 for cooling, and finally leads out from the air duct 3 under the sheath 101 and contacts the wind turbine structure installed at the tail end of the bracket 2. The wind turbine structure is used to mix the hot air that has passed through the transformer 1 with the cold air that has not passed through the transformer to form an air vortex, thereby accelerating the extraction of hot air from the transformer 1;

[0053] The wind turbine structure includes a wind tube 4 installed at the tail ends of two brackets 2. The head and tail ends of the wind tube 4 are through-connected with the two brackets 2 and the connection is sealed. A vertically upward guide rod 401 is installed on the inner bottom surface of the wind tube 4, and the top of the guide rod 401 is connected to an electric fan blade 405.

[0054] The rear wall of the support rod 102 connected to the sheath 101 forms an air duct 3, and the head end and the top opening of the air duct 3 are used to receive natural wind force. As the natural wind enters the air duct 3 from the air, it is squeezed to form a canyon effect, thereby increasing the wind speed, and then the accelerated natural wind contacts the transformer inside the sheath 101, wherein the air duct 3 below the bracket 2 also contacts the air at the same time, and the air in the air duct 3 below the bracket 2 drives the hot air to move into the wind tube 4 after further entering. At this time, the hot air with high temperature enters the wind tube from the bottom of the wind tube 4, and the wind force in the air duct above the bracket 2 is lost through multiple sheaths 101 and the remaining cold air is discharged from the wind tube 4 enters its inner side from the top. At this time, there are hot and cold air in the wind tube 4 at the same time, and the hot air rises and the cold air falls. Inside the wind tube 4, due to the continuous rise of the hot air, an ascending airflow is formed, and the cold air enters the top of the wind tube through the air duct 3 above the bracket 2, forming a steady-state convection. Due to the movement and interaction of the hot and cold air inside the wind tube 4, an eddy current phenomenon will be generated. The rise of the hot air and the fall of the cold air not only promote the circulation of the internal air, but also form an air vortex in the wind tube, thereby further extracting the outside air. At this time, the outside air is input into the inside of the wind tube 4 from the two air ducts 3, and further cools the transformer 1 naturally.

[0055] Specifically, an air guide plate 301 is installed inside the air duct 3 above the transformer 1. The air guide plate 301 is a curved surface and the bottom is inclined toward the downward sheath 101. The inclination angle of the air guide plate 301 is between 15° and 45°. The bottom of the air duct 3 below the transformer 1 is sealed, and only the air inlet is retained.

[0056] The wind is introduced from the air duct 3 into the sheath 101 by tilting the air guide plate 301 downward. The greater the tilt angle of the air guide plate 301, the more air is introduced. The air duct 3 located below the transformer 1 can only introduce wind from the front opening when the lower opening is sealed. At this time, the wind enters the air duct 3 and is guided to the inside of the wind tube 4.

[0057] Specifically, a guide plate 302 is installed at the bottom of the inner side of the air duct 3 below the bracket 2 . The bottom of the guide plate 302 is connected to the inner bottom surface of the air duct 3 , and the top is tilted upwardly connected to the inner side of the air cylinder 4 , so as to deliver hot air into the air cylinder 4 .

[0058] The hot air is guided into the air duct 4 through the air duct guide plate 302 below the bracket 2, so that the hot air enters the inner bottom of the air duct 4. At this time, the air duct 4 is relatively still, and the hot air begins to rise.

[0059] The guide plate 302 installed on the inner side of the air duct below the bracket 2 allows the auxiliary wind to enter the wind tube 4 in an upwardly inclined manner, thereby further reducing the loss of wind during the movement.

[0060] Specifically, the inner side of the sheath 101 is horizontally connected to the transformer 1 using a support rod 102. The front end of the support rod 102 is bolted to the inner wall of the sheath 101 and the rear end is bolted to the side wall of the transformer 1. The support rod 102 is a copper-aluminum alloy. The sheath 101 is fixedly connected to the transformer 1 through the support rod 102. A gap of the length of the support rod 102 is formed between the sheath 101 and the transformer 1 to accommodate the passage of cold air, so that the cold air contacts the transformer for cooling.

[0061] The support rod 102 is used to separate a gap between the sheath 101 and the transformer 1, and the inner side of the cylindrical sheath 101 allows wind power to be transmitted more quickly and comprehensively.

[0062] Embodiment 2

[0063] The wind force distribution of the wind in the duct after passing through the guide plate is calculated as:

[0064] For the inlet and outlet wind speeds of each wind deflector 301, the initial wind force is calculated:

[0065]

[0066] Where: P total is the total wind force; ρ is the density of air, 1.225, kg / m 3 ; A is the cross-sectional area of ​​the air duct, unit: m 2 ; is the total wind speed before passing through all guide plates, unit: m / s;

[0067] Calculation of the influence of the guide plate

[0068]

[0069] in:

[0070] ΔP i is the pressure loss caused by the i-th guide plate, unit: Pa; K i is the loss coefficient related to the shape and angle of the i-th guide plate; V i is the wind speed before the i-th guide plate, unit: m / s;

[0071] Wind speed change calculation

[0072]

[0073] Where: V i+1 is the wind speed after the i+1th guide plate, unit: m / s; V i is the wind speed before the i-th guide plate, unit: m / s;

[0074] The total loss is calculated as:

[0075]

[0076] Where: ΔP total is the total pressure loss of the entire system, unit: Pa; n is the total number of guide plates;

[0077] Wind loss calculation

[0078] P final =P total -ΔP total

[0079] ΔP loss =P total -P final

[0080] Where: P final is the remaining wind force after passing through all guide plates, unit: W; ΔP loss is the total wind loss, unit: W.

[0081] Parameters: Air density ρ: 1.225kg / m 3 ; Air duct cross-sectional area A: 2m 2 Total wind speed 10m / s; number of guide plates n: 3; loss coefficient of each guide plate K i :

[0082] K1=0.5; K2=0.3; K3=0.2;

[0083] Wind speed before each wind deflector 301:

[0084] V1=10m / s

[0085]

[0086] The efficiency ratio of each air guide plate 301 is:

[0087]

[0088] Calculate the total wind force P total :

[0089]

[0090] Calculate the pressure loss ΔP for each guide plate i :

[0091] For the air guide plate 3011: ΔP1 = 0.5 0.6125 100 = 30.625 Pa;

[0092] For air deflector 3012:

[0093] First calculate

[0094] Next, calculate ΔP2:

[0095] For guide plate 3: V3 = V2 × (1-efficiency ratio2 )=9×(1-0.15)=9×0.85=7.65m / s;

[0096] ΔP3=0.2*0.6125*58.6225=7.1965pa;

[0097] Calculate the total pressure loss ΔP total

[0098] ΔP total =ΔP1+ΔP2+ΔP3=30.625+14.975+7.1965=52.7965Pa

[0099] Calculate the remaining wind force P after passing through all guide plates final :P final =P total -ΔP total =122.5-52.7965=69.7035; unit: w;

[0100] Total wind loss ΔP loss :ΔP loss =P total -P final =122.5-69.7035=52.7965; unit: w;

[0101] Where pa is the unit, the air pressure value

[0102] Specifically, the wind force received by the wind tube is calculated as:

[0103]

[0104] Where: V n is the wind speed after the last guide plate, unit: m / s; V1 is the initial wind speed at the air duct entrance, unit: m / s; is the proportion of wind speed loss caused by the i-th guide plate: dimensionless; n is the total number of guide plates.

[0105] Specifically, an air guide ring 406 is installed on the top of the wind tube 4. The air guide ring 406 is spirally bent and has a hollow center. The top of the air guide ring 406 is at the same height as the wind tube 4 and the tail end of the air duct 3 located on the top of the transformer 1.

[0106] The air flow at normal temperature inside the air duct 3 at the top of the transformer 1 is guided by the air guide ring 406 to enter the inside of the air cylinder 4 and then contact the hot air downward to complete the intersection.

[0107] Specifically, a through opening 407 sealedly connected to the air duct 3 is provided at the bottom of the air cylinder 4 near the air duct 3, and a fan 408 is installed inside the through opening 407. The air outlet of the fan 408 faces the inside of the air cylinder 4 and the rear faces the inner center of the air duct 3.

[0108] The ducting fan 408 is used to start when the transformer 1 needs forced cooling. After the ducting fan 408 is started, it rotates rapidly to form a negative pressure area at the rear, thereby quickly introducing the hot air in the air duct 3 below the transformer 1 into the air cylinder 4.

[0109] Specifically, a closing structure for closing the gap between the sheath 101 and the outside world is movably installed on the side wall of the bracket 2 near the sheath 101. The closing structure includes a closing plate 5 made of rubber material. A sliding rail and a slider are arranged at the connection of the rear wall of the closing plate 5. The rear wall of the closing plate 5 is also connected to a driving structure arranged in the "C"-shaped hollow part of the bracket 2.

[0110] When the driving structure receives the forced cooling instruction, it drives the closing plate 5 to flip downward to cover the gap between the sheath 101 and the outside world, so that only the air duct 3 is retained as the air inlet. At this time, the electric fan blades 405 inside the wind tube 4 are started synchronously to transport the hot air upward faster to complete the intersection with the cold air. As the hot air continues to rise, an upward airflow is formed, and the cold air enters the top of the wind tube through the air duct 3 above the bracket 2, forming a steady-state convection. Due to the movement and interaction of the hot and cold air inside the wind tube 4, an air vortex is formed in the wind tube, which further draws outside air, and the vortex wind speed is higher than that under normal conditions, and the heat dissipation is faster.

[0111] Specifically, the driving structure includes a connecting rod 6 whose front end is hingedly connected to the rear wall of the closing plate 5 and whose rear end is fixedly connected to the steering wheel 7 arranged in the "C"-shaped hollow part of the bracket 2. The connecting rod 6 is hinged to the slider, and a servo drive motor is installed inside the steering wheel 7. The servo drive motor is used to drive the steering wheel to rotate and drive the connecting rod 6 to swing.

[0112] The servo motor has a built-in single-chip microcomputer, which is also connected to the electric fan blades 405 and the guide fan 408 by wires. When the temperature of the transformer 1 reaches the forced cooling threshold, the single-chip microcomputer starts the above devices to perform forced cooling. Further, the temperature threshold belongs to the existing technology, and its detection temperature and threshold startup are mature equipment on the market, which will not be introduced here.

[0113] During use, air enters through the air duct 3 located below the bracket 2 and drives the hot air to move into the wind tube 4. At this time, the hot air with high temperature enters the wind tube from the bottom of the wind tube 4, and the remaining cold air enters the inner side of the wind tube 4 from the top after the wind force in the air duct above the bracket 2 is lost through multiple sheaths 101. At this time, there are both hot and cold air in the wind tube 4, and the hot air rises and the cold air falls. Inside the wind tube 4, due to the continuous rise of the hot air, an ascending airflow is formed, and the cold air enters the top of the wind tube through the air duct 3 above the bracket 2, forming a steady-state convection. Due to the movement and interaction of the hot and cold air inside the wind tube 4, a vortex phenomenon will be generated. The rise of hot air and the fall of cold air not only promote the circulation of the internal air, but also form an air vortex in the wind tube, thereby further extracting outside air. At this time, the outside air is input into the inner side of the wind tube 4 from the two air ducts 3, and further cools the transformer 1.

[0114] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An energy-saving and environment-friendly dry-type power transformer, comprising a bracket (2) supporting a transformer (1) body, wherein the bracket (2) is "C"-shaped and symmetrically mounted on both sides of the upper and lower ends of the transformer, and characterized in that: A sheath (101) is installed at the connection between the outer side of the transformer (1) and the bracket (2), and the upper and lower ends of the sheath (101) are butt-jointed with the air duct (3) at the central part of the inner side of the bracket (2); The air duct (3) is formed by the rear walls of the two brackets (2) being close to each other, and is used to guide natural wind into the sheath (101) to cool the transformer (1). The wind guide plate (301) arranged in the air duct (3) guides the wind from the air duct (3) into the sheath (101) and makes the wind contact the transformer (1) for cooling, and finally guides the wind from the air duct (3) below the sheath (101) to contact the wind turbine structure installed at the rear end of the bracket (2). The wind turbine structure is used to mix the hot air that has passed through the transformer (1) with the cold air that has not passed through the transformer to form an air vortex, thereby accelerating the extraction of hot air from the transformer (1); The wind turbine structure comprises a wind tube (4) installed at the rear ends of two brackets (2); the front and rear ends of the wind tube (4) are connected to the two brackets (2) in a through-type manner and the connection is sealed; a vertically upward guide rod (401) is installed on the inner bottom surface of the wind tube (4); and the top of the guide rod (401) is connected to an electric fan blade (405).

2. The energy-saving and environment-friendly dry-type power transformer according to claim 1 is characterized in that: An air guide plate (301) is installed inside the air duct (3) above the transformer (1), and the air guide plate (301) is a curved surface with a sheath (101) whose bottom is inclined downward.

3. The energy-saving and environment-friendly dry-type power transformer according to claim 2 is characterized in that: A guide plate (302) is installed at the bottom of the inner side of the air duct (3) below the bracket (2); the bottom of the guide plate (302) is connected to the inner bottom surface of the air duct (3), and the top is connected to the inner side of the air cylinder (4) in an inclined manner upward, so as to send hot air into the air cylinder (4); the inclination angle of the guide plate (302) is between 15° and 45°.

4. The energy-saving and environment-friendly dry-type power transformer according to claim 3 is characterized in that: The inner side of the sheath (101) is transversely connected to the transformer (1) using a support rod (102); the front end of the support rod (102) is bolted to the inner wall of the sheath (101) and the rear end is bolted to the side wall of the transformer (1); the support rod (102) is made of copper-aluminum alloy; the sheath (101) is fixedly connected to the transformer (1) via the support rod (102); a gap of the length of the support rod (102) is formed between the sheath (101) and the transformer (1) to accommodate the passage of cold air, so that the cold air contacts the transformer for cooling.

5. The energy-saving and environment-friendly dry-type power transformer according to claim 4 is characterized in that: The wind force distribution of the wind in the air duct after passing through the guide plate is calculated as: For each guide vane inlet and outlet wind speed, calculate the initial wind force: Where: P total is the total wind force; ρ is the density of air, 1.225, kg / m 3 ; A is the cross-sectional area of ​​the air duct, unit: m 2 ; is the total wind speed before passing through all guide plates, unit: m / s; Calculation of the influence of air guide plate (301) in: ΔP i is the pressure loss caused by the i-th air guide plate (301), unit: Pa; K i is the loss coefficient related to the shape and angle of the i-th air guide plate (301); V i is the wind speed in front of the i-th wind guide plate (301), unit: m / s; Wind speed change calculation Where: V i+1 is the wind speed after the i+1th wind guide plate (301), unit: m / s; V i is the wind speed in front of the i-th wind guide plate (301), unit: m / s; The total loss is calculated as: Where: ΔP total is the total pressure loss of the entire system, unit: Pa; n is the total number of air guide plates (301); Wind loss calculation P final =P total -ΔP total ΔP loss =P total -P final Where: P final is the remaining wind force after passing through all wind deflectors (301), unit: W; ΔP loss is the total wind loss, unit: W.

6. The energy-saving and environment-friendly dry-type power transformer according to claim 5, characterized in that: The wind force received by the wind tube (4) is calculated as: Where: V n is the wind speed after the last wind guide plate (301), unit: m / s; V1 is the initial wind speed at the air duct entrance, unit: m / s; is the wind speed loss ratio caused by the i-th guide plate: dimensionless; n is the total number of guide plates (301).

7. The energy-saving and environment-friendly dry-type power transformer according to claim 6 is characterized in that: An air guide ring (406) is installed on the top of the wind tube (4); the air guide ring (406) is spirally curved and has a hollow center portion; the top of the air guide ring (406) is at the same height as the wind tube (4) and the tail end of the air duct (3) located at the top of the transformer (1).

8. The energy-saving and environment-friendly dry-type power transformer according to claim 7 is characterized in that: A through opening (407) sealedly connected to the air duct (3) is provided at the bottom of the air cylinder (4) near the air duct (3), and a guide fan (408) is installed inside the through opening (407). The air outlet of the guide fan (408) faces the inside of the air cylinder (4) and the rear side faces the inner center of the air duct (3).

9. The energy-saving and environment-friendly dry-type power transformer according to claim 8, characterized in that: A closing structure for closing a gap between the sheath (101) and the outside world is movably installed on the side wall of the bracket (2) near the sheath (101), and the closing structure comprises a closing plate (5) made of rubber material, and a slide rail and a slider are arranged at the connection of the rear wall of the closing plate (5), and the rear wall of the closing plate (5) is also connected to a driving structure arranged in the "C"-shaped hollow part of the bracket (2).

10. The energy-saving and environment-friendly dry-type power transformer according to claim 9, characterized in that: The driving structure comprises a connecting rod (6) whose front end is hingedly connected to the rear wall of the closing plate (5) and whose rear end is fixedly connected to a steering wheel (7) arranged in a "C"-shaped hollow of a bracket (2); the connecting rod (6) is hingedly connected to a slider; a servo drive motor is installed inside the steering wheel (7); the servo drive motor is used to drive the steering wheel to rotate and drive the connecting rod (6) to swing.

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