Transformer oil regeneration
The duration of a normal operation of transformers is determined by the state of magnetic circuits and cellulose insulation. In theoretical terms, the service life of magnetic circuits can be virtually unlimited, however, the cellulose insulation ages in a constant and much more intensive manner. Therefore, the service life of a transformer depends mainly on its condition.
The natural aging of cellulose insulation is a long process, but there are a number of factors that accelerate it, namely heating, exposure to moisture and oxygen, as well as the effects of aging oil products that tend to accumulate.
Oil Regeneration and Cellulose Insulation Cleaning
It is noteworthy that it is the cellulose that acts as an oil filter, because it delays and concentrates its aging products. In most cases, the concentration of detrimental impurities in solid insulation is greater than in the liquid one. Thus, cleaning cellulose is one of the most important tasks in order to extend the service life of transformer. It can be divided into two subtasks:
- oil regeneration;
- washing cellulose insulation.
Consider the existing methods of cleaning cellulose insulation. Complete transformer oil replacement cannot solve the problem, because almost immediately a part of aging products from solid insulation passes into new oil. The process is repeated in a circle - aging products oxidize a fresh product, it intensively ages and saturates the cellulose with newly formed degradation products. Thus, the costs for fresh transformer oils are not justified in the context of transformer equipment service life extension.
Oil drain, its subsequent regeneration and flooding in terms of the final effect is identical to a simple oil replacement, though it is cheaper.
It is possible to wash the insulation during the overhaul of the transformer. This method involves removing the aging products from the cellulose surface by spraying clean process oil. The disadvantage of this approach is that it does not allow the removal of aging products in the bulk of the insulation. The efficiency of washing is enhanced by the use of special detergent oils with removing properties. But they are quite expensive, and the process itself should last longer than usual. It is worth mentioning only one figure, i.e. costs for repair and washing oils to clean cellulose can amount to 30% of the price of a new transformer.
Oil Regeneration Equipment
In order to extend the service life of power transformers, it is recommended to use the CMM-R plants manufactured and supplied by GlobeCore. They are highly efficient oil regeneration systems. The main distinguishing feature of CMM-R is the ability to work with the insulating fluids of an operating transformer. This feature makes GlobeCore equipment an effective tool in solving problems of cleaning cellulose insulation.
The general principle of the CMM-R plants is as follows. First they are connected to a transformer in operation. Then, the oil circulates through the unit. The contaminated product is taken from the transformer, and then it passes through the regeneration and degassing units. Purified and reconstituted oil is returned. High circulation speed allows washing off the aging products from a solid insulation. The oil with the washed substances is returned to the CMM-P plant, where it is repeatedly degassed and regenerated. Thus, multiple treatment of the entire volume of both transformer oil and cellulose is achieved.
Other advantages of the CMM-R plants include:
- minimal oil losses in the adsorbent pores;
- simultaneous oil reclamation and cleaning of solid insulation;
- environmentally safe regeneration of the fuller's earth absorbent inside the plant;
- continuous operation of the transformer;
- increased life cycle of cellulose insulation by removing aging products that lead to irreversible destructive processes;
- increased life cycle of a transformer.
Transformer oils perform several functions. They operate as liquid insulation and heat dissipation medium in oil filled switches, transformers, power cables and high voltage capacitors. Besides, they also act as arc extinguisher.
Transformer oil is made by purification of petroleum oils, made in turn from crude oil. The crude oil originates from various sources, and the types of crude oil may vary in terms of chemical composition, influencing the oil products.
During operation, transformer oils accumulate oxidation products and other contaminants, which reduce their performance and lifetime, as well as the lifetime of the whole transformer system.
Purification (regeneration) of transformer oils facilitates removal of water, solid particles, acids as well as other undesirable components (asphalt, tar, nitric and sulfuric compounds, certain hydrocarbons). Let us review the operations, performed during regeneration of transformer oils.Industry literature recommends the following sequence of methods: mechanical, heating, physical and chemical, followed by chemical. It should be noted that the last group of methods is only used if the previous have unsatisfactory effect. The use of chemical methods requires more complicated equipment and is rather costly.
After transformer oil treatment at GlobeCore SMM-R plants, its parameters fully comply with the requirements of the international standard IEC 60296.
By maintaining performance characteristics of oils at this level, it is possible to ensure the extension of the service life of both cellulose insulation and transformer, and save finances on unscheduled repairs and possible equipment standby periods.
Globecore regeneration systems
Besides, our equipment is environmentally friendly. This factor is very important today, because to have investors motivated, manufacturers have got to demonstrate “green” and environmentally friendly approaches. CMM-R unit reactivates sorbent except of oil regeneration.
This will not only have environmental benefits, but will also result in cost saving on purchasing the new and disposing of the used oil, as well as extend transformer lifetime by 20 years or more.
GlobeCore manufactures oil regeneration systems for both transformer manufacturers and for transformer service providers.
GlobeCore manufactures and supplies equipment for purification of transformer, industrial, turbine and other types of oils. GlobeCore oil recycling plants are convenient, practical and functional. Their operation is not accompanied by harmful emissions into atmosphere. In addition, they consume minimal power, helping to save on expenses.Oil filtration unit.