Objectives :

To enrich knowledge about industrial sector . To know about the function of radiator . To enrich the basic business knowledge . To know about the functions of ISO .

Introduction :

Radiators are heat exchangers used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in automobiles, buildings, and electronics. The radiator is always a source of heat to its environment, although this may be for either the purpose of heating this environment, or for cooling the fluid or coolant supplied to it, as for engine cooling. Despite the name, most radiators transfer the bulk of their heat via convection instead of thermal radiation (the main exception to this rule being the radiators on spacecraft, see spacecraft radiators below), though the term "convector" is used more narrowly; see radiation and convection, below.

The Roman hypocaust, a type of radiator for building space heating, was described in 15 AD. The heating radiator was invented by Franz San Galli, a Polish-born Russian businessman living in St. Petersburg, between 1855 and 1857.

One might expect the term "radiator" to apply to devices that transfer heat primarily by thermal radiation (see: infrared heating), while a device which relied primarily on natural or forced convection would be called a "convector". In practice, the term "radiator" refers to any of a number of devices in which a liquid circulates through exposed pipes (often with fins or other means of increasing surface area). The term "convector" refers to a class of devices in which the source of heat is not directly exposed.

Radiators are commonly used to heat buildings. In a central heating system, hot water or sometimes steam is generated in a central boiler, and circulated by pumps through radiators within the building, where this heat is transferred to the surroundings.Radiators are used for cooling internal combustion engines, mainly in automobiles but also in

piston-engined aircraft, railway locomotives, motorcycles, stationary generating plants and other places where such engines are used.

To cool down the engine, a coolant is passed through the engine block, where it absorbs heat from the engine. The hot coolant is then fed into the inlet tank of the radiator (located either on the top of the radiator, or along one side), from which it is distributed across the radiator core through tubes to another tank on the opposite end of the radiator. As the coolant passes through the radiator tubes on its way to the opposite tank, it transfers much of its heat to the tubes which, in turn, transfer the heat to the fins that are lodged between each row of tubes. The fins then release the heat to the ambient air. Fins are used to greatly increase the contact surface of the tubes to the air, thus increasing the exchange efficiency. The cooled coolant is fed back to the engine, and the cycle repeats. Normally, the radiator does not reduce the temperature of the coolant back to ambient air temperature, but it is still sufficiently cooled to keep the engine from overheating.

This coolant is usually water-based, with the addition of glycols to prevent freezing and other additives to limit corrosion, erosion and cavitation. However, the coolant may also be an oil. The first engines used thermo siphons to circulate the coolant; today, however, all but the smallest engines use pumps.

Up to the 1980s, radiator cores were often made of copper (for fins) and brass (for tubes, headers, and side-plates, while tanks could also be made of brass or of plastic, often a polyamide). Starting in the 1970s, use of aluminum increased, eventually taking over the vast majority of vehicular radiator applications. The main inducements for aluminum are reduced weight and cost. However, the superior cooling properties of Copper-Brass over Aluminum makes it preferential for high performance vehicles or stationary applications. In particular MW-class installations, copper-brass constructions are still dominant (See: Copper in heat exchangers). CuproBraze is a copper-alloy heat exchanger technology for harsh temperature and pressure environments such as those in the latest generations of cleaner diesel engines mandated by environmental regulations.[3][4] Its performance advantages over radiators made with other materials include better thermal performance, heat transfer, size, strength, durability, emissions, corrosion resistance, reparability, and antimicrobial benefits.

Since air has a lower heat capacity and density than liquid coolants, a fairly large volume flow rate (relative to the coolant's) must be blown through the radiator core to capture the heat from the coolant. Radiators often have one or more fans that blow air through the radiator. To save fan

power consumption in vehicles, radiators are often behind the grille at the front end of a vehicle. Ram air can give a portion or all of the necessary cooling air flow when the coolant temperature remains below the system's designed maximum temperature, and the fan remains disengaged.

As electronic devices become smaller, the problem of dispersing waste heat becomes more difficult. Tiny radiators known as heat sinks are used to convey heat from the electronic components into a cooling air stream. Heat is transferred to the air by conduction and convection; a relatively small proportion of heat is transferred by radiation owing to the low temperature of semiconductor devices compared to their surroundings.

Radiators are found as components of some spacecraft. These radiators work by radiating heat energy away as light (generally infrared given the temperatures at which spacecraft try to operate) because in the vacuum of space neither convection nor conduction can work to transfer heat away. On the International Space Station these can be seen clearly as large white panels attached to the main truss. They can be found on both manned and unmanned craft.

Function of Radiator :

When an electrical transformer is loaded, the current starts flowing through it’s windings. Due to this flowing of electric current, heat is produced in the windings, this heat ultimately rises the temperature of transformer oil. We know that the rating of any electrical equipment depends upon its allowable temperature rise limit. Hence, if the temperature rise of the transformer insulating oil is controlled, the capacity or rating of transformer can be extended up to significant range.

The radiator of transformer accelerates the cooling rate of transformer. Thus, it plays a vital role in increasing loading capacity of an electrical transformer.

This is basic function of radiator of an electrical power transformer. Oil immersed power transformer is generally provided with detachable pressed sheet radiator with isolating valves. But in case of small size distributing transformer, the radiators are generally integrated parts of transformer body and projected from the main tank.

The working principle of radiator is very simple. It just increases the surface area for dissipating heat of the oil. In case of electrical power transformer, due to the transport limitation, this units are sent separately and assembled at site with transformer main body. At the time of dispatching, the flings of radiator are blanketed by gasket and blanketing plates. The radiator valves on the main tank are also blanketed by gasket and blanketing plates.

Operation of Radiator :

Under loaded condition, warm oil increases in volume and comes to the upper portion of the main tank. Then this oil enters in the radiator through top valve and cools down by dissipating heat through the thin radiator wall. This cold oil comes back to the main tank through the bottom radiator valve. This cycle is repeated continuously till the load is connected to the transformer.

Dissipation of heat in the transformer radiator; can be accelerated further by force air provided by means of fans. These fans are fitted either on the radiator bank itself or fitted nearby the bank but all the fans must be faced towards the radiator. Sometime, the cooling rate of convectional circulation of oil is not sufficient. That time an oil pump may be used for speeding up oil circulation.

Process flow Chart of Thermocool Engineering Pvt. Ltd.

Order Received from client pressing(Cutting)

Placement of Order to size sheet Roll forming

Incoming measurement of raw material Corrugation forming

Physical measurement of Material Spot Welding

Material cut to size as per specification Side Seam Weldingof client

Pocket Cutting

Formation of two parts of half pipe

Assembling & Welding

Surface Preparation for Painting

Painting

Leakage Testing

If testing is OK then releasing of If not OK thenProduct for final of external surfaces

Dispatching of Materials

Figure : Transformer Radiator

Manufacturing Process of Thermocool Engineering Pvt. Ltd. , risks and their Mitigation :

1. Receiving of order from client :The orders normally comes from the transformer manufacturers as the radiator used for the cooling action of transformer .In that case the client surely give the dimensions and specifications of that product .

Risk: Sometimes it happened that the order was taken without hearing or recording exact dimension , which can causes loss of the factory .

Mitigation :The dimensions , specifications should be checked if any confusion arise or directly ask the client about his order .

2. Physical Measurement of Material : To get the final goods with perfect measurement it must be done that all measurement of the initial raw material must be perfect and without that the best product can’t be produced .

Risk : There have some problem in the measuring process which can bring the measurement problem .

Mitigation : The measuring instrument must be checked at least once after a certain period .

3.Power Press Cutting :It is a process of separating a certain portion of metal form it base .

Risk : As it is a manual process , it can be very normal to occur the deviation in the length or width of the required bar .

Mitigation : The dimensions must be checked after a certain number of production , overall to maintain the production with profit it could be done after every 50 piece production .

4. Hydraulic Press cutting : It can be most perfect process for cutting materials .

Risk : A risk was seen in the machine that all the cutting gives 10mm deviation which can show loss of the industry .

Mitigation : As it is a problem of machine that can be repair by changing the input coding or another preventing action can be taken which can be make the worker known about that and tell then to input 10mm less than the exact measurement . And to avoid the mistake of then this could be noted on the machine in bangla or hindi so that every worker can understand that .

5. Spot Welding : Spot welding is a process in which conducting metal surfaces are jointed by the heat obtained from resistance to electric current .

Risk :

It is done by resistance spot welding machine in which the welding quality mostly depend on the machine which can be reduced because of lacking of checking that machine .

Mitigation :

It is possible to bring best welding efficiency by checking the machine and its accessories or mountings regularly . It could be done after a certain period which can be once a month .

6.Side Seam Welding : It is a variation of resistance spot welding .In resistance spot welding , the welding electrodes are motor driven wheels as opposed to stationary rods . The result is rolling resistance weld or non hermetic seam weld . This process is most often used to join two sheet of metal together .

Risk :It is done by Side seam welding machine in which the welding quality mostly depend on the machine which can be reduced because of lacking of checking that machine .There can be occur any accident because of unusual use of coolant .

Mitigation : It is possible to bring best welding efficiency by checking the machine and its accessories or mountings regularly . It could be done after a certain period which can be once a month .There have to use water perfectly for the better cooling action .

7. Leakage Testing :

It is a process of testing the existence of any kind of leakage in the radiator body and for that the whole body was emerged under water at a pressure of 2kg/cm dial for nearby 30 min . If there have any kind of leakage water bobble can be seen in the water otherwise it don’t show any effect in water .

Risk :

If the man appointed for the leakage test was not careful for that 30 min and failed to see the water bobbles that could be make a mistake and for the arrangement of further checking the factory have to bear extra losses .

Mitigation : It can be mitigated by depending on machine more than the appointed persons . The dial size can be larger to understand the testing results clearly .

Figure : Leakage Testing

Figure : Full Transformer System With Radiators

Training on ISO 9001:2015 :

The International Organization for Standardization (ISO) is an international standard-setting body composed of representatives from various national standards organizations.

Founded on 23 February 1947, the organization promotes worldwide proprietary, industrial and commercial standards. It is headquartered in Geneva, Switzerland and as of 2015 works in 196 countries.

It was one of the first organizations granted general consultative status with the United Nations Economic and Social Council.

ISO International Standards ensure that products and services are safe, reliable and of good quality. For business, they are strategic tools that reduce costs by minimizing waste and errors and increasing productivity. They help companies to access new markets, level the playing field for developing countries and facilitate free and fair global trade.

This training held in Thermocool Engineering Pvt. Ltd. And only for the help of TEPL I can join the training program and able to gain knowledge about the ISO certification program and also able to know the importance to know about ISO as a industrial engineering student .

By the training I also able to gain a perfect knowledge about business objectives which doesn’t lines only in profit but also environment and community . That give me a visual flowchart of success of business .

ISO 9001:2015 training also makes me able to know about some core terms such as PDCA(Plan – Do – Check – Act ) and so many which may help in my professional life and I feel proud to take such a wonderful training.

Figure : PDCA ( A basic business thinking)

Working Experience in Thermocool Engineering Pvt. Ltd.(TEPL) :

As a student of Industrial Engineering I learn a lot from TEPL . All the employee of this factory was so much helpful and friendly . I successfully completed my internship at TEPL with my effort along with the help of all the people engaged with this factory . Most of the time I was tried to memorize my theoretical knowledge and also try to compere it with the practical knowledge and I got a lots of matching .

In Manufacturing Process I and Manufacturing Process II, the process of all kinds of welding was learned but a few was seen in practical in the lab , but by the help of this internship I saw all of them in practical and also saw the use of those in large scale of production .

Plan

Do

Check

Act

In Heat Transfer , the knowledge about fins was gained but unfortunately that was not seen . But in the internship huge knowledge was gained about fins because a transformer radiator is all about fin which is used to increase heat lose in transformer .

All of the theoretical knowledge about fins helps a lot to understand the working procedure of that .

In Industrial law , the safety of a industry was studied . But in this attachment all those was seen and made me understand about the importance of that .