Heat is produced in the windings and core of the transformer due to the flow of electric current through the windings and the losses that occur in the core. The temperature of the transformer oil climbs as a direct result of this heat. In light of the fact that the rating of any piece of electrical equipment is dependent on its maximum permitted temperature rise, cooling the transformer oil is an absolute necessity. Therefore, the rating of the transformer can be prolonged up to a large limit if the temperature rise of the transformer’s insulating oil can be managed. The radiator of the transformer has a significant impact on the rate at which it cools down. As a result, it plays a significant role in enhancing the loading capacity of the transformer. Radiators’ fundamental and primary function is to facilitate the cooling of transformer oil.
Transformer Radiator Functions and Operations
After a transformer has been loaded, the current will begin to flow through the windings of the device. The windings generate heat as a result of the flow of electric current, and it is this heat that ultimately causes the temperature of the transformer oil to rise. We are aware that the permitted temperature increase limit of any piece of electrical equipment determines the rating of that piece of equipment. Therefore, the capacity or rating of the transformer can be extended to a large range if the temperature rise of the transformer’s insulating oil is regulated. The rate at which the transformer cools down is sped up by the radiator. As a result, it plays a significant role in the process of improving the loading capacity of an electrical transformer. This is the fundamental role that the radiator plays in a power transformer.
Detachable pressed sheet radiators with isolating valves are typically included with an oil-immersed power transformer’s standard equipment. However, in the case of distribution transformers of a smaller size, the radiators are typically constructed as integral elements of the transformer body and are projected from the main tank. The operation of a radiator is based on a straightforward idea. It does nothing more than increase the surface area available for the oil’s heat to escape. In the case of an electrical power transformer, these units, which cannot be transported together with the transformer’s main body due to space constraints, are shipped separately and assembled on site. The gasket and blanketing plates are used to cover the flanges of the radiator before it is shipped off. In addition, gaskets and blanketing plates are used to cover the radiator valves that are located on the main tank.
Warm oil has a greater volume when the main tank is loaded, therefore it rises to the upper part of the tank. After that, the oil travels through the top valve and into the radiator, where it absorbs heat from the surrounding air and eventually cools down. Through the bottom radiator valve, this chilly oil is sent back to the primary storage tank. This cycle will keep going around and around until the load is finally linked to the transformer. Dissipation of heat within the transformer radiator; this process can be sped up even more by the application of force air generated by fans. These fans can be installed either directly on the radiator bank or somewhere nearby, but they must all be oriented such that the airflow is directed at the radiator. Sometimes the rate of cooling that is achieved by the convectional circulation of oil is insufficient. At that point, an oil pump might be utilized to speed up the circulation of the oil.
Assembly of Radiators in Transforms:
When removing radiators from their shipping crates, one should exercise extreme caution. One should likewise exercise extreme caution when handling the radiator bank and installing it. This is due to the fact that radiator units are manufactured from very thin sheets of steel of metal for the purpose of good transfer of heat from oil that air. As a result, even the smallest of damages can cause oil to seep out of the bank. After being removed from their containers, these radiators need to have their exteriors cleaned. These must also be clean on the inside and be flashed with transformers insulating oil in order to meet the requirements.
The radiator units have to be assembled one at a time, which means that the mounting and fastening of one item has to be finished in every respect before moving on to the next one. The process of assembly needs to begin on one side and go to the other side till it is complete. Remove the blanketing covers from the top and bottom radiators valves before proceeding with the assembly of the unit. During the process of removing the blanketing plates, an old gasket should be replaced with a new one if the surface of the gasket is damaged. After that, the radiator assembly would be raised to a vertical position and moved closer to the main tank valves that corresponded to each tank. At this point, take off the blanketing plates that are located on the main tank valves. Nuts, bolts, plain washers, and spring washers are used to secure the radiator flange to the appropriate valve of the main tank. Finish putting together the remaining radiator units in the same way.