Tag Archives: oil treatment

Canada. The CMM-4/7 unit for oil reclaiming successfully services transformers of wind turbines

Oil reclaiming extends power transformer service life fro 15 years.

GlobeCore is a member of the American Wind Energy Association (AWEA), and always tries to find solutions to the urgent problems in the industry.

Among the tasks are: increasing reliability and extending service life of wind turbine transformers. These transformers convert the voltage of turbine generators for power lines. They are positioned within the tower or near the tower base.

Recently one of GlobeCore CMM-4/7 oil reclaiming units started operation on a wind farm in Canada. This equipment is designed for degassing, removal of free and dissolved water and solids from insulating oil. Also, it heats the oil before filling transformers and other electrical equipment. The secret to high performance of the CMM units are the activators that contribute to instantaneous evaporation of gases and water from oil.

The unit is compact and portable. It quickly services the wind turbine transformers located in remote areas.

CMM oil reclaiming units are available with a wide range of additional options:

  • additional vacuum system for vacuumizing of transformers;
  • two-stage refrigeration system to increase the efficiency of the vacuum system;
  • moisture sensors at both input and output of transformer oil;
  • remote control and oil reclaiming process monitoring;
  • thermal insulation;
  • metal container;
  • special room for the operator;
  • explosion-proof;
  • mounted on wheels;
  • trailer or semitrailer.

GlobeCore equipment for maintenance of wind turbine transformers:

  • Improves alternative energy transmission;
  • Extends the lifetime of the transformer;
  • Saves money on purchase of new insulating oils.

Transformer Damage and Oil Regeneration/Oil Reclamation

An electric power transformer Damage is one of the most important elements of the modern electric grid no matter where in the world a particula grid may be located.  Transformer failures result in significant financial expenditures, and will require the transmission company to buy new transforners or repair the damaged ones at significant cost and service interuptions.

Many historians note that there was great industrial boom observed in the first decade followintg the end of World War II.  At that time, there was a rapid increase in electric power consumption.  To meet the growing demand for electric power, new transformers had to constantly be put into operation.  Since that time, mant of the older transformers have become outdated and pose a big risk of unscheduled service interuptions.

Older transformers’ obsolescence however, is not the only problem facing the modern power grids.  The power loads on the obsolete transformers are increasing because of ever increasing power consumption.  It requires significant expenditures to replace the broken or obsolete transformer since the price for a new transformer is very high.

It is therefore, advisable to take measures to extend the service life of transformers already in service.  To succeed in undertaking a sucessful preventive maintenance program, one should understand the nature of the failures that make transformers unserviceable in the first place.

In 2003, the International Association of Engineering Insurers (IMIA) started to explore the reasons for transformer failures servicing the combined USA power grids.  The results were rather interesting.  Table 1 shows the economic losses caused by different types of transformer failures.

Table 1

Economical Losses Caused by Different Transformer failures

Nature of Failure

Amount of Cases

Economical Loss in $

Insulation defects

24%

149,967,277.00

Problems with designing, material or installation

22%

64,969,051.00

Unknown failures

15%

29,776,245.00

Oil contamination

4%

11,836,367.00

Overloading

5%

8,568,768.00

Inflammation/explosion

3%

8,045,771.00

Network overvoltage

4%

4,959,691.00

Operational failures

5%

3,518,783.00

Water ingress

2%

2,240,198.00

Poor contacts

6%

2,186,725.00

Lightning stroke

3%

657,935.00

Insulation moistening

1%

175,000.00

In total

94%

286,628,811.00

It is not an overstatement to say that if proper and timely preventive maintenance of the insulating systems is performed, many, if not all transformer failures can be prevented.  The insulating system of the power transformer consists of bith solid and liquid insulation.  The solid insulation is made of hygroscopic material (cellulose) also known as “Kraft Paper.”  The liquid insulation features a dielectric fluid known as transformer insulating oil.  In general, these two kinds of insulation are interdependent, but also help to contaminate each because degradation products from the solid insulation may get into oil and oil oxidation sludges may penetrate into the solid insulation from the oil.  Simply changing the transformer oil therefore, will not completely resolve the problem of restoring and cleaning the entire insulation system.  Unfortunatelt, oxidation products are accumulated in the cellulose insulation and are not removed when oil is simply changed.  And when only an oil changed is performed, these oxidation products will migrate get into new oil accelerating the aging process of the new oil and shortening its effective service life.  Additionally, the contamination that remains in the solid insulation will continue to degrade and damage the Kraft Paper leading to transformer failure.

This problem may be solved with the advanced GlobeCore regeneration technologies.  The GlobeCore mobile oil recycling stations, designated as the CMM-R line of equipment may be connected to either an energized or non-energized transformer.  In such a way, oil is circulated through a closed path: used oil flows to the oil treatment station and goes back to the transformer being cleaned and restored.  The contaminants resulting from the aging process are washed out due to the constant circulation. This advanced type of equipment performs a complete oil regeneration service and removes all contamination for the transformer core, windings and solid insulation.

GlobeCore mobile oil stations perform  the following operations:

  1. filtration with or without heating (processed oil is of 9th ISO 4406 purity class and with nominal filtration fineness, ranging from 0.5…1 micron);
  2. dehydration (the moisture content of the processed oil is no more than 5 g/t (5ppm);
  3. degassing (volumetric gas content of the processed oil is no more than 0.1 %);
  4. increase the dielectric breakdown voltage (no less than  70 kV (kilovolt));
  5. drying of electrical equipment and oil purification simultaneously;
  6. regenerate insulating oil, using bleaching clay;
  7. vacuum transformers and other electrical equipment;
  8. remove acids;
  9. remove soluble oil decomposition products;
  10. lighten insulating oil; and
  11. restore oxidation and gasification stability;

The GlоbeCоre technologies provide for service life extension of transformers and reduction of financial expenditures on maintenance.  Save money with GlоbeCоre!

Breaking news! Our engineers have just developed and constructed a new degassing plant, the CMM-6D, which has been successfully tested and put into production!

Breaking news!
Our engineers have just developed and constructed a new degassing plant, the CMM-6D, which has been successfully tested and put into production.

SAM_4949 Копия SAM_4954

DEGASSING UNIT CMM-6D

Degassing unit CMM-6D has been designed to clean electrical and turbine oils by removing mechanical impurities as well as water and gases using a thermal vacuum purification process.

The main features of this degassing unit are:

1. Automatic Touch Pad Controls

Копия SAM_4952

2. Using only one oil pump
3. Operation is controlled automatically
4. Energy saving equipment: oil is heated according to pre-set performance standards
5. Vacuuming of many other types of equipment

The purifier operates in the following modes:
– «out vacuum mode»
– «heating filtration mode»
– «vacuum mode»
– «degassing mode»
– «manual mode»

Parameters:
1 Capacity, м3/hour
– degassing, drying and filtration mode 2-6
– heating and filtration mode 2-6
2* Properties of purified oil:
– volumetric gas content % 0.5
– volumetric water content, ppm,
– filtration fineness, microns 1
3.Size and mass, mm
– length 3700
– width 1750
– height 2320
4. Mass, kg 2600

Oil reclamation equipment will extend life of your transformers and safe your money

Oil Reclamation Systems

oil reclamation

The main purpose and benefit of transformer oil reclamation is to completely restore the insulating oil back to new like condition without having to buy new oil or dispose of old oil.

The GlobeCore Process of oil reclamation is performed by extracting water/moisture, acids, particulate matter and other undesirable contaminates such as unsaturated hydrocarbons, asphalt-resinous substances, sulfur and nitrogen compounds from the oil.  The process of regenerating transformer oil uses various technologies based on (1) physical, (2) physico-chemical and (3) chemical processes.

There are several chemical methods of deep oil reclamation.  The most common one consists of  an acid-alkaline-earth method.  This method of oil purification is based on treating the oil with sulfuric acid.  The sulfuric acid acts to compact and bind all the unstable compounds into an acid sludge oil.  Tar is then removed by “settling” and the remains of the sulfuric acid and organic acids are neutralized by the use of an alkali treating oil.  Following that, the oil is washed with distilled water, dried and treated for complete neutralization with bleaching earth.  After final filtration, the oil becomes completely regenerated.

Transformer Oil Recloil reclamation unit CMM 6R with degassingamation Methods

  • Mechanical – To remove from the oil moisture/water and solid contaminants (filtration, centrifugal action, sludge removal);
  • Thermo-physical – evaporation, vacuum distillation;
  • Physico-chemical – coagulation, adsorption;
  • Chemical – if three methods are not enough, this method involves the usage of much more difficult and costly equipment.

Physical Methods of Reclamation of Transformer Oil

The physical method of transformer oil reclamation is usually referred to as purification by removing mechanical impurities and water, i.e. drying.

All Transformer oils, (whether new, old, or operational), that are contaminated by mechanical impurities and water, can be corrected in most cases by one of the following reclamation methods as long as there have been no changes in its chemical properties or other the significant changes that have altered the basic qualities of the oil.  Undesirable contaminates that deteriorate the initial properties of the oil, can be dissolved in the oil or found in the oil in an undissolved state.  Thanks to mechanical cleaning, these undesirable  contaminates can be removed from the oil.

Oil Drying

The most advanced and cost effective method of oil drying is by spraying the oil under vacuum at a low temperature.  The solution of the oil and water is sprayed through a nozzle that is placed in a tank of water in which “under-pressure” is created.  Thus the free and dissolved moisture and the dissolved air are removed from oil.  When the oil is “thin dispersed” it quickly gives up its moisture. Dry oil, as droplets, then fall to the bottom of the vacuum tank.

The efficiency and speed of drying rate is further increased by heating the oil.  This increases the evaporation process of the water.  Oil loss from evaporation is insignificant.  The rate of water evaporation from oil will also depend on the difference between the pressure of saturated steam at a given temperature and the residual pressure in the vacuum tank.

Download catalog in pdf (eng)

 

GlobeCore’s engineer with a collegue from Saudi Arabia after successful start of equipment

The choice of the plant was far from random. The CMM-10 is a versatile unit, allowing heat and vacuum treatment not only of transformer oil, but also turbine, industrial and other oils. The oil is restored by removing water, gas and various solid particles.

The CMM-10 plant has a wide range of application. If can be used for installation, repairs and operation of oil filled high voltage equipment, sealed or breathing. up to 1150 kV.

Besides, the CMM-10 can successfully heat equipment with hot oil, introduce nitrogen into the oil and add oil into high voltage systems.

The unit is protected from overloads, overheating and short circuit of controls, pumps, drives, lights and heaters.

The CMM-10 stops in case of phase skipping, incorrect phase connection, as well as overheating of oil from or the oil heater. Light and sound alarms are available.

The plant is simple in operation and can be used both indoors and outdoors.