An energy-saving and environmental protection type dry-type power transformer

Abstract

The present invention relates to the technical field of transformers, and discloses an energy-saving and environment-friendly dry-type power transformer, which includes a bracket for supporting the transformer body. The bracket is in a "C" shape and is symmetrically installed on both sides of the upper and lower ends of the transformer. A sheath is installed at the connection between the outer side of the transformer and the bracket, and the upper and lower ends of the sheath are butt-jointed to the air ducts at the central part inside the bracket. In the present invention, hot air with a high temperature enters the air duct from below the air cylinder. Inside the air cylinder, due to the continuous upward movement of the hot air, an upward air flow is formed, while the cold air enters the top of the air cylinder 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 cylinder, an eddy current phenomenon will occur, and the transformer will be naturally cooled further, achieving the beneficial effect of improving the natural wind force efficiency of the dry-type transformer.

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 cylinder installed at the ends of two brackets. The head and tail ends of the wind cylinder are connected to the two brackets in a penetrating manner and the connection parts are sealed. A guide rod perpendicular to the upward direction is installed on the inner bottom surface of the wind cylinder, and the top of the guide rod is connected to an electric fan blade.

[0010] Preferably, a wind guide plate is installed inside the air duct. The wind guide plate is a curved surface and the bottom is inclined towards the lower sheath.

[0011] Preferably, a guide plate is installed at the inner bottom 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 and connected to the inner side of the wind cylinder for sending hot air into the wind cylinder. The inclination angle of the guide plate is between 15° and 45°.

[0012] Preferably, the inner side of the sheath is horizontally connected to the transformer using a support rod. The head end of the support rod is bolted to the inner wall of the sheath and the tail end is bolted to the side wall of the transformer. The support rod is made of copper-aluminum alloy. The sheath is fixedly connected to the transformer through the support rod. A gap with the length of the support rod is formed between the sheath and the transformer for cold air to pass through, so that the cold air contacts the transformer to cool it down.

[0013] Preferably, the wind force distribution calculation after the wind in the air duct passes through the guide plate is as follows:

[0014] For the inlet and outlet wind speeds of each wind guide plate, calculate the initial wind power:

[0015]

[0016] Where: P total is the total wind power; ρ is the density of air, which is 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 the wind guide plates, unit: m / s;

[0017] Calculation of the influence of the guide plate

[0018]

[0019] Where:

[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] Calculation of wind speed change

[0022]

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

[0024] The total loss is calculated as:

[0025]

[0026] Wherein: ΔP total is the total pressure loss of the whole system, unit: Pa; n is the total number of air deflectors;

[0027] Calculation of wind force loss

[0028] P final = P total - ΔP total

[0029] ΔP loss = P total - P final

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

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

[0032]

[0033] Wherein: V n is the wind speed after the last air deflector, unit: m / s; V 1 is the initial wind speed at the air duct inlet, unit: m / s; is the wind speed loss ratio caused by the i-th deflector: dimensionless; n is the total number of deflectors.

[0034] Preferably, an air guiding ring is installed at the top of the air duct. The air guiding ring is bent in a spiral shape and has a hollow center. The top of the air guiding ring is at the same height as the air duct and the tail end of the air duct located at the top of the transformer.

[0035] Preferably, a through port for sealing connection with the air duct is provided on one side of the air duct near the bottom of the air duct. A guiding fan is installed inside the through port. The air outlet of the guiding fan faces the inside of the air duct, and the rear is directly opposite to the center of the inside of the air duct.

[0036] Preferably, a closing structure for closing the gap between the sheath and the outside is movably installed near the side wall of the bracket. The closing structure includes a closing plate made of rubber. A slide rail and a slider are arranged at the connection of 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 of the bracket.

[0037] Preferably, the driving structure includes a connecting rod with its head end hinged to the rear wall of the closing plate and its tail end fixedly connected to a steering wheel arranged in the "C"-shaped hollow of the bracket. The connecting rod is hinged to the slider. A servo drive motor is installed inside the steering wheel. The servo drive motor is used to drive the steering wheel to rotate self 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, having the following beneficial effects:

[0039] 1. In the present invention, the rear wall of the support rod connected to the sheath forms an air duct. The head end and the top opening part of the air duct are used to receive natural wind. Since the natural wind is squeezed when entering the air duct from the air, a channel effect is formed to increase the wind speed. Then the accelerated natural wind contacts the transformer inside the sheath. Since the air duct under the bracket also contacts the air at the same time, the air entering the air duct under the bracket further drives the hot air to move towards the inside of the air cylinder. At this time, the hot air with high temperature enters the air cylinder from below the air cylinder, and the wind force in the air duct above the bracket enters the inside of the air cylinder from the top of the air cylinder after being lost through multiple sheaths. At this time, there are hot and cold air in the air cylinder at the same time, and the hot air rises and the cold air descends. Inside the air cylinder, due to the continuous rising of the hot air, an upward air flow is formed, and the cold air enters the top of the air cylinder through the air duct above the bracket, forming a steady convection. Due to the movement and interaction of the hot and cold air in the air cylinder, an eddy current phenomenon will occur. The rising of the hot air and the descending of the cold air not only promote the circular flow of the internal air, but also form an air vortex in the air cylinder, thereby further extracting the outside air. At this time, the outside air is input into the inside of the air cylinder from the two air ducts, and further naturally cools the transformer, achieving the beneficial effect of improving the natural wind efficiency of the dry-type transformer.

[0040] 2. In the present invention, a single-chip microcomputer is built into the servo motor, and the single-chip microcomputer is connected to the electric fan blade and the guiding fan wire. When the temperature of the transformer reaches the forced cooling threshold, the single-chip microcomputer starts the above devices. After the guiding fan starts and rotates rapidly, a negative pressure area is formed at the rear, so that the hot air in the air duct below the transformer is quickly introduced into the air cylinder. The closing plate flips downward to cover the gap between the sheath and the outside, so that only the air duct is reserved as the air inlet. At this time, the electric fan blade inside the air cylinder starts synchronously, so as to convey the hot air upward faster to complete the intersection with the cold air. Since the hot air continuously rises, an upward air flow is formed, and the cold air enters the top of the air cylinder through the air duct above the support, forming a steady-state convection. Due to the movement and interaction of the hot and cold air inside the air cylinder, an air vortex is also formed in the air cylinder, further extracting the outside air, with a higher eddy current wind speed and faster heat dissipation than in the normal state, 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 is a schematic diagram of the overall structure of the present invention;

[0042] Figure 2 is a front sectional view of the air cylinder structure of the present invention;

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

[0044] Figure 4 is a front sectional view of the sheath structure of the present invention;

[0045] Figure 5 is an enlarged schematic diagram of the closing plate structure of the present invention;

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

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

[0048] Wherein: 1. Transformer; 101. Sheath; 102. Support rod; 2. Support; 3. Air duct; 301. Air guiding plate; 302. Guide plate; 4. Air cylinder; 401. Guide rod; 405. Electric fan blade; 406. Air guiding ring; 407. Through hole; 408. Guiding fan; 5. Closing plate; 6. Connecting rod. DETAILED DESCRIPTION OF THE EMBODIMENTS

[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. The front end and the top opening part of the air duct 3 are used to receive natural wind. Since the natural wind is squeezed when entering the air duct 3 from the air, a channeling effect is formed, which increases the wind speed. Then the accelerated natural wind contacts the transformer inside the sheath 101. Since the air duct 3 below the bracket 2 also contacts the air at the same time, further, the air entering the air duct 3 below the bracket 2 drives the hot air to move into the air cylinder 4. At this time, the hot air with high temperature enters the air cylinder from below the air cylinder 4, and the wind force in the air duct above the bracket 2 enters the inside of the air cylinder 4 from the top of the air cylinder 4 after being lost through multiple sheaths 101. At this time, there are both hot and cold air in the air cylinder 4, and the hot air rises and the cold air descends. Inside the air cylinder 4, due to the continuous rising of the hot air, an upward air current is formed, and the cold air enters the top of the air cylinder 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 air cylinder 4, an eddy current phenomenon will occur. The rising of the hot air and the descending of the cold air not only promote the circulating flow of the internal air, but also form an air vortex in the air cylinder, thereby further extracting the outside air. At this time, the outside air is input into the inside of the air cylinder 4 from the two air ducts 3 and further naturally cools the transformer 1.

[0055] Specifically, a wind guide plate 301 is installed inside the air duct 3 above the transformer 1. The wind guide plate 301 is a curved surface and the bottom is inclined towards the sheath 101 below. The inclination angle of the wind 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 reserved.

[0056] The wind force is introduced from the air duct 3 into the sheath 101 through the downward inclination of the wind guide plate 301. Further, the larger the inclination angle of the wind guide plate 301, the more air volume is introduced. The air duct 3 below the transformer 1 can only introduce wind force from the front opening when the lower opening is sealed. At this time, after the wind force enters, it is guided into the air cylinder 4 in the air duct 3.

[0057] Specifically, a guide plate 302 is installed at the inner bottom 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 inclined upward and connected to the inner side of the air cylinder 4 for sending the hot air into the air cylinder 4.

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

[0059] The auxiliary wind force enters the air cylinder 4 through the guide plate 302 installed inside the air duct below the bracket 2 in an inclined upward posture, further reducing the loss of the wind force during the movement.

[0060] Specifically, the inner side of the sheath 101 is horizontally connected to the transformer 1 by means of a support rod 102. The head end of the support rod 102 is bolted to the inner wall of the sheath 101 and the tail 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 through the support rod 102. A gap with the length of the support rod 102 is formed between the sheath 101 and the transformer 1 for cold air to pass through, so that the cold air contacts the transformer to cool it down.

[0061] A gap is separated between the sheath 101 and the transformer 1 by using the support rod 102, and the inner side of the cylindrical sheath 101 enables the wind power transmission to be faster and more comprehensive.

[0062] Embodiment 2

[0063] The wind force distribution calculation after the wind in the air duct passes through the guide plate is as follows:

[0064] For the inlet and outlet wind speeds of each air guide plate 301, calculate the initial wind power:

[0065]

[0066] Among them: P total is the total wind power; ρ is the density of air, which is 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 the guide plates, unit: m / s;

[0067] Calculation of the influence of the guide plate

[0068]

[0069] Among them:

[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] Calculation of wind speed change

[0072]

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

[0074] The total loss calculation is:

[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 power after passing through all the guide plates, unit: W; ΔP loss is the total wind loss, unit: W.

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

[0082] K 1 = 0.5; K 2 = 0.3; K 3 = 0.2;

[0083] Wind speed in front of each air guide plate 301:

[0084] V 1 = 10 m / s

[0085]

[0086] Efficiency ratio of each air guide plate 301:

[0087]

[0088] Calculate the total wind power P total :

[0089]

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

[0091] For air guide plate 3011: ΔP 1 = 0.5 · 0.6125 · 100 = 30.625 Pa;

[0092] For the air deflector 3012:

[0093] First, calculate

[0094] Secondly, calculate ΔP 2 :

[0095] For the deflector 3: V 3 = V 2 ×(1 - efficiency ratio2 ) = 9×(1 - 0.15) = 9×0.85 = 7.65m / s;

[0096] ΔP 3 = 0.2 * 0.6125 * 58.6225 = 7.1965pa;

[0097] Calculate the total pressure loss ΔP total

[0098] ΔP total = ΔP 1 + ΔP 2 + ΔP 3 = 30.625 + 14.975 + 7.1965 = 52.7965Pa

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

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

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

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

[0103]

[0104] Where: V n is the wind speed after the last deflector, unit: m / s; V 1 is the initial wind speed at the air duct inlet, unit: m / s; is the wind speed loss ratio caused by the i-th deflector: dimensionless; n is the total number of deflectors.

[0105] Specifically, a wind guide ring 406 is installed at the top of the air duct 4. The wind guide ring 406 is bent in a spiral shape and has a hollow center part. The top of the wind guide ring 406 is at the same height as the end of the air duct 3 located at the top of the transformer 1 and the air duct 4.

[0106] The wind guide ring 406 guides the normal-temperature air flow inside the air duct 3 at the top of the transformer 1 into the inside of the air duct 4 and then contacts the hot air downward along with it to complete the intersection.

[0107] Specifically, a through port 407 sealed and connected to the air duct 3 is provided on one side of the bottom of the air duct 4 close to the air duct 3. A guide fan 408 is installed inside the through port 407. The air outlet of the guide fan 408 faces the inside of the air duct 4, and the rear is directly opposite to the center inside the air duct 3.

[0108] The guide fan 408 is used to start when the transformer 1 needs forced cooling. After the guide fan 408 starts and rotates rapidly, a negative pressure area is formed at the rear, so that the hot air inside the air duct 3 below the transformer 1 is quickly introduced into the inside of the air duct 4.

[0109] Specifically, a closing structure for closing the gap between the sheath 101 and the outside 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 slide rail and a slider are provided 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 receiving a forced cooling instruction, the driving structure drives the closing plate 5 to turn downward to cover the gap between the sheath 101 and the outside, so that only the air duct 3 is reserved as the air inlet. At this time, the electric fan blade 405 inside the air duct 4 starts synchronously, so as to convey the hot air upward faster to complete the intersection with the cold air. Since the hot air continuously rises, an upward air flow is formed, and the cold air enters the top of the air duct 4 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 air duct 4, an air vortex is also formed in the air duct, further extracting the outside air, with a higher eddy current wind speed than in the normal state and faster heat dissipation.

[0111] Specifically, the driving structure includes a connecting rod 6 with its head end hinged to the rear wall of the closing plate 5 and its tail end fixedly connected to a steering wheel 7 arranged in the "C"-shaped hollow part of the bracket 2. The connecting rod 6 is hinged to the 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 self and drive the connecting rod 6 to swing.

[0112] The servo motor is built-in with a single-chip microcomputer. At the same time, the single-chip microcomputer is electrically connected to the electric fan blade 405 and the guide fan 408. 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 prior art, and its temperature detection and threshold activation are all mature devices on the market, so no more introduction will be made here.

[0113] In use, after air enters through the air duct 3 located below the bracket 2, it drives the hot air to move into the interior of the air cylinder 4. At this time, the hot air with a high temperature enters the air cylinder from below the air cylinder 4, while the remaining cold air after passing through multiple sheaths 101 in the air duct above the bracket 2 enters the inner side of the air cylinder 4 from the top of the air cylinder 4. At this time, both hot and cold air exist inside the air cylinder 4, and the hot air rises while the cold air descends. Inside the air cylinder 4, due to the continuous rising of the hot air, an upward air current is formed, and the cold air enters the top of the air cylinder 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 air cylinder 4, an eddy current phenomenon will occur. The rising of the hot air and the descending of the cold air not only promote the circular flow of the internal air but also form an air vortex in the air cylinder, thereby further extracting the external air. At this time, the external air is input into the inner side of the air cylinder 4 through the two air ducts 3 and further cools the transformer 1.

[0114] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. 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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