Application analysis of dry transformer in cement plant
Date：2019-08-21 15:16 Source：cementepcViews:
Dry type transformer refers to the transformer whose core and winding are not impregnated in insulating oil.
1.Advantages of dry type transformer
The dry type transformer in cement plant has simple structure, stable operation, good maintenance performance, less space and convenient fault diagnosis.
(1) the dry transformer is sealed by epoxy resin, with good insulation and high coil strength, which can prevent the winding or iron core from being affected by moisture.
(2) considering the requirement of fire prevention, when installing transformer indoors, the oil-type transformer shall be installed in a separate transformer room and connected to the low-voltage wire inlet cabinet in adjacent rooms through copper busbar or cable, which is far away.Dry type transformer parallel cabinet does not need a separate transformer room, it can be directly adjacent to the copper bar of low-voltage inlet cabinet, and the connection length of the copper bar of the parallel cabinet is very short.
(3) before the installation of oil-type transformer, it is necessary to carry out core inspection, oil filtering, gas calibration relay and other preparatory work. The installation of dry-type transformer and cabinet is simple and quick.
(4) the dry-type transformer with shell adopts forced air cooling system and has automatic temperature control system, which is more stable and reliable than the natural cooling of oil-type transformer.
(5) oil type transformer needs regular inspection by operators, while cement plant dry type transformer can be maintenance-free.
(6) oil type transformer room shall be designed to avoid exposure to sunlight, which is often limited in general layout and road maintenance.
2. Cost comparison between dry transformer and oil transformer
2.1 civil construction cost of oil-type transformer room
According to the cement plant conventional design estimate, 5mx4.5m oil transformer corresponding to the transformer room civil engineering quantity, including: wall (area 12.1m2), a transformer room special doors and Windows (steel shutter doors and Windows) : door (area :10.8m2), window (area: 3.6m2).Concrete consumption is 150m3 and steel reinforcement consumption is 0.19t.Because domestic and foreign construction unit price is different, after accounting, the domestic cement plant transformer room civil construction cost of about 50,000 yuan, southeast Asia and central Asia civil construction cost of 60 ~ 100,000 yuan.Dry type transformer does not need to build transformer room, this part of cost can be saved.
2.2 low voltage cable cost
The low voltage cable between oil type transformer and low voltage cabinet can be saved by using dry type transformer with shell and low voltage cabinet.Because this section of cable is a large section of cable, the cost is high, can not be ignored.Table 1 estimates the cost of this section of cable, considering that the distance from the oil-type transformer room to the incoming cabinet of the adjacent low-voltage distribution room is 15m.
2.3 transformer installation cost
The installation cost of oil-type transformer includes the equipment and material cost of transformer room, temperature and smoke detector and piping, as well as the workload of transformer installation and oil filtering. The installation of dry-type transformer with shell is equivalent to the installation workload of a low-voltage cabinet, and the installation and auxiliary material cost can save tens of thousands of yuan.In addition, the transportation of dry transformer with shell is safer and more reliable than that of oil transformer.
3 application scope
Although the current scheme of dry-type transformer merging cabinet has great promotion value, it also has certain application scope, which needs attention:
(1) this paper compares and analyzes the indoor transformer layout scheme. If the transformer is arranged outdoors, the oil-type transformer will be more economical.
(2) the price of dry transformers of domestic brands is relatively low, but the price of dry transformers of foreign brands is still very high. Therefore, when the supplier short list of EPC project is foreign brands, attention should be paid to the selection of dry transformers.
(3) heat value should be considered when designing the parallel cabinet of dry-type transformer. The heat value should be calculated according to about 0.7% of the transformer capacity. The actual heat value should be subject to the data provided by the transformer manufacturer.
Dry type transformer has certain advantages in technical performance and economy.With the further promotion of the concept of green plant, energy conservation and emission reduction, especially in the current fire control, environmental protection acceptance requirements increasingly strict situation, dry transformer more promotion and application value.Jiangsu LVSSN can provide high quality and efficient cement plant construction, please consult our customer service or leave a message to us, we will reply to you as soon as possible.