supplyOre furnace transformer

1. The user's pursuit of the mineral furnace transformer

The development of the market economy has also changed the expectations of users on the products they buy. In the past, some users, because they are familiar with transformers, put forward a lot of constraints when ordering. Such as the magnetic flux density of the iron core, the winding current density, the weight of the transformer, etc., if it is not rejected, it will have an adverse effect on the overall use efficiency of the product, because the progress of materials and structures, some constraints are often counterproductive, such as the iron core: Too low magnetic flux density will inevitably lead to an increase in the amount of iron used, and the no-load loss, not a direct decline, most of the trend is increasing, the amount of iron core, the diameter increases the winding diameter, the length of each turn of wire increases, the load loss increases, and the overall use efficiency decreases, in recent years, the user's requirements have changed greatly, but also promote the development of new energy-saving calcium carbide furnace transformers. Now as our transformer manufacturers pursue four points: first, the product empty, load loss to be low; Second, the product reliability is good, long life; The third is to have a certain overload capacity (overload 20% long-term use); Fourth, complete as little maintenance as possible. According to the requirements of users, our company has eliminated all the products produced three years ago, and most of the orders placed by users are new designs, changing the face of the products, and users have achieved good economic benefits.

2. Improvement of transformer materials, structure, process, etc

A complete transformer for mineral furnace is mainly divided into six parts: iron core, winding, body, fuel tank, assembly, accessories.

(1) Iron core: In terms of material, we have selected 30Q130 silicon steel sheet made by Wisco or 30Z130 silicon steel sheet made by Nippon Steel Co., LTD., Japan, which is basically consistent with the materials used in international developed countries.

In the structure of the use of full oblique joint plate type, the upper and lower clamp connection of low magnetic steel plate tensile plate structure, changed the previous square iron structure, so that the iron chip without holes, the core of each section of the magnetic flux density is consistent, no distortion, in the shearing process imported from Germany Georg shear line, The control of shear burr <0.02mm (standard <0.05 is qualified product) per meter length tolerance <0.2mm, thereby increasing the laminating coefficient and reducing the gap between seams, avoiding local overheating of the iron core, reducing product noise and no-load loss and no-load current.

(2) Winding: From the material of oxygen free copper electromagnetic wire progress is not big, our company mainly controls its ρ20℃<0.017241, and mainly controls its paper insulation material and tightness, the purpose is to try to make the coil has a better shaft, radial stability, coil with small oil gap, internal and external oil shielding plate, guided cooling, cardboard tube structure, Make the structure compact overload capacity, thermal stability, loss is also reduced.

For large on-load voltage regulation and 110kV class products, the "8" type coils are all wound once to increase the strength of the coil and reduce the eddy current loss.

(3) The body: all the wood parts of the body are laminated wood, which improves the rigidity of the lead frame. The upper and lower pressing plates are made of cardboard or epoxy resin forming parts, which increases the insulation distance between the conductive body and the ground compared with the iron pressing plate, and can reduce the "window height" size. The primary and secondary main insulation adopts imported cardboard to increase the strength of the main insulation, and the multi-coil adopts the overall set to improve the reliability of the product. The body is dried by Norwegian vapor phase drying equipment, drying thoroughly and without damaging the insulation, and has the role of washing the body.

(4) Oil tank: The oil tank adopts folding plate, minimizes the weld, increases the strength and makes positive and negative pressure test to ensure the reliability of the product seal, and uses low magnetic steel plate or magnetic shield in the appropriate part to reduce the additional loss caused by the magnetic field of the bus conductor on the box wall. This work has achieved very good results in seepage prevention and loss reduction.

(5) Final assembly: After the body is dry, the winding relaxation is pressed by hydraulic equipment to achieve good results, and the vacuum oil injection reduces the bubbles in the winding, reduces the partial discharge, and increases the life of the product. The use of new anti-aging sealing materials, so that the original leakage problem can be improved.

All control lines such as: gas relays, signal thermometers, resistance thermometers, pressure relief valves, magnetic fuel gauges, CT, etc. are uniformly introduced into the junction box on the box, and the overall beauty of the transformer has been improved.

(6) Accessories: The main accessory water cooler uses YS1 oil-water cooler, or stainless steel spiral plate cooler, and the high pressure casing uses the discharge type to increase the creepage distance.

The on-load tap-changer uses the "M-type" or "V-type" of the domestic advanced manufacturers in addition to requiring a remote display, there is a remote control interface, and an online oil device can be added to the switch if necessary.

The transformer oil is cyclic alkyl anti-aging transformer oil produced in Karamay, Xinjiang, and the protection of the oil is a fully closed structure (that is, the pressure relief valve with diaphragm oil storage tank structure).

3. Discussion on the development trend of mineral furnace transformer

Due to the improvement of the production process of the ore furnace, the structure of the transformer has also had a great impact, such as the development of fully closed smelting, prompting the transformer above 15000kVA, designed as a single-phase transformer, water-cooled pipe (adjustable copper pipe) side outlet, load regulation, unified cooling structure, such products have been produced multiple sets.

4. Some views on transformer maintenance:

It is necessary for the core to be transported for a long distance after the arrival of the product, mainly to solve the fastener loosening during transportation and the user's acceptance of the manufacturer's products. However, as for the routine overhaul, we believe that it is necessary to check and replace those mechanical wear parts according to the original overhaul cycle. Such as pumps and other moving parts, but the relatively static transformer can be long-term without lifting the core, only monitoring the change of the gas chromatographic analysis value of the oil is enough to grasp the situation of the body, so as to save maintenance costs, reduce the core of the body and oil pollution.