Significance of Thermodynamics in Engineering

                Thermodynamics developed out of curiosity of the famous scientist Nicolas Léonard Sadi Carnot (1824) who believed that the efficiency of the machines and weapons could be achieved by the temperature control of the devices. Thermodynamics started in this way and soon became very important in any Engineering field. 

                Nowadays, thermodynamics is the basis of any engineering branch. The first law of Thermodynamics applies to any energy conversion process. So, any engineering process related to heat transfer and power generation utilizes this law. Similarly, the second law of thermodynamics is used in power generation cycles, as it deals with reversible and irreversible processes. Therefore, in any branch of engineering, thermodynamics plays a vital role. Thus studying Thermodynamics is very important in the engineering domain.

The significance of Thermodynamics in specific domains are as follows:

Manufacturing/Industrial Industry

                Considered the world’s largest industry, manufacturing transforms billions of raw materials into useful products. Like all real processes and systems, manufacturing processes and equipment are subject to the first and second laws of thermodynamics and can be modeled via thermodynamic formulations.

                Industrial processes—manufacturing or servicing—involve one or more forms of electrical, mechanical, chemical (including nuclear), and thermal energy conversion processes. For a manufactured component, an interpretation of the first law of thermodynamics indicates that the internal energy content of the component is the energy that formed the product. Cursorily, this sums all the work that goes into the manufacturing process from electrical to mechanical, chemical, and thermal power consumption by the manufacturing equipment. However, from experience, not all of this energy goes into the material-to-product transformation. Energy dissipation (or loss) via heat generation in the machine (most machines run hot enough to require active cooling during operation) also comes from the input power; this all involves knowledge related to thermodynamics.

                For example in manufacturing processes like recycling plastic. Recycling plastic required melting it down, turning it into pellets, combining those plastic pellets with other additives, and melting it down to make new plastic products. Recycling metal is similar but without the pelletizing process.

                Making printed circuit boards requires heat to essentially glue together the layers, and you have to heat everything up to solder electronic components like resistors and capacitors into place. Thermodynamics often affects quality control. Variations in the temperature from the narrow ideal range result in product variations. This is why process improvement in certain manufacturing operations focuses on keeping the oven or soldering station temperature very tight.

Automobile Industry

                       

                The concept of the thermodynamics applied to heat engines is equally applicable to the internal combustion engines used in our cars, motorcycles, ships, airplanes. 

• When compression is complete, the spark plugs ignite the fuel, which then increases the temperature and pressure at a constant volume. Then the gas expands adiabatically, called the “power stroke,” resulting in a sudden drop in the pressure and temperature. Some part of the heat generated inside the engine is used to perform the work of moving pistons inside the engine cylinder. This part of the reaction is what gives power to the car and here we can understand the use of thermodynamics in cars.
• An air conditioner works using a thermodynamic cycle called the refrigeration cycle. It does this by changing the pressure and state of the refrigerant to absorb or release heat. The refrigerant (aka coolant) absorbs heat from the inside of your home and then pumps it outside.
• According to the Second Law of Thermodynamics, heat will always flow spontaneously from hot to cold, and never the other way around. A refrigerator causes heat to flow from cold to hot by inputting work, which cools the space inside the refrigerator.
• A heat engine makes use of the properties of thermodynamics(First law) to transform heat into work. Heat transfer of energy to the gas in the cylinder results in work being done.
• The heating cycle of a heat pump works by taking heat in from the air outside, warming it up further, and using this warm air to heat indoor air. The liquid refrigerant absorbs heat in the "evaporator" from the outdoor air, turning it into a gas.

   

    

Civil Industry 

                Engineering Thermodynamics plays a major role in the civil industry as in heating, ventilation, and air conditioning(HVAC). By using the basic laws and principles of thermodynamics people can live comfortably in buildings by using energy in smarter ways. Within a building/apartment, all of the heating & cooling equipment is governed by thermodynamics. For eg: Heat transfer in solid building components is a combination of convection, radiation & conduction which relates to thermodynamics: 
at the inner surface of a component convective heat exchange takes place between air and surface and radiative heat exchange between the surrounding surfaces and the inner surface; inside the materials, the process is a combination of conduction through the solid phase and a combination of convection, conduction, and radiation in the air cavities; inside a components layer of air, it is also a combination of convection, conduction, and radiation; at the outer surface, it is a combination of convection and radiation.

Electrical Engineering

                Excess of heat in any electrical or electronic device can damage it. So, it is very important to use appropriate coolant to cool that system down. But most of this work is done by mechanical engineers. Thermodynamics is important in the following aspects of electrical Engineering.

• In an Integrated system of electronic devices, to control temperature and heat dissipation.
• Application of cooling systems for electronic devices, especially liquid cooling systems.
• Electricity generation power plants, turbines and energy loss in them.
• Thermistors, the controlling temperature of semiconductors.

          

Chemical Industry

                The thermodynamic properties of fluids are of key importance for the chemical industry. A Chemical Engineer is concerned with Physical operations or unit processes has to Evaluate energy requirements, study energy changes involved in physical operations like Heat transfer, filtration processes, and chemical processes like Oxidation, catalysis. In Chemical engineering the chemical analysis of Heat engines and heat power cycles are done. This is why Thermodynamics plays an important role in chemical engineering.
Some applications of Thermodynamics in chemical engineering:

• It helps to calculate the maximum amount of work of fuel in a steam engine.
• Maximum efficiency of turbines can also be calculated.
• Helps standardize the parameters like pressure, temperature, etc. in several chemical and physical processes.

Textile Engineering

The process of converting fiber in the fabric in several processes is called textile engineering. This process involves various chemical processes as well as the quality of the fiber drawn is dependent on atmospheric conditions like temperature. There are a few procedures like fabric drying, boiler, and dye fixation that require combustion of fuel, and a few processes like fabric compression require electricity. Thus, thermodynamics gets involved in the process automatically. 
Eg. While dying natural fabric, around 140 to 160 degrees Celsius temperature is required, and artificial fabric needs a higher temperature. 

Aerodynamic Engineering

                In Aerospace engineering, thermodynamics is totally different well as it is very important. It relates to the combustion of rocket fuel and energy generation, which ensures the efficiency of the vehicle. It is also important to optimize the performance of instruments and cooling systems within, and a lot more. 

Instrumentation Engineering

                In domestic and industrial instruments’ maintenance, temperature plays an important role. Excessive heat can damage the instrument or reduce its performance. In our household chores as well, refrigerators and Air conditioners are very important. These instruments work mainly on thermodynamic principles. So, thermodynamics is very important in instrumentation engineering. 

Metallurgical / Petroleum Engineering

                The second law of thermodynamics applies to all thermal systems such as petroleum refining, oxygen production, or steelmaking.
                "The second law of thermodynamics is considered to be the most fundamental law of science. It explains not only the working of engines, refrigerators, and other equipment used in our daily life but also highly advanced theories like the big bang, the expansion of the universe, heat death, etc. Another important application of the second law of thermodynamics is found in refrigerators and heat pumps, which are based on the principle of reversed Carnot cycle or reversed Carnot theorem. The second law of thermodynamics says that heat can flow from high-temperature reservoir to low-temperature reservoir only, however, if you want to move the heat from low temperature to high-temperature reservoir, then the external work has to be supplied"

This way, Thermodynamics plays a very important role in every engineering field.

Blog by:

Vishwakarma Institute of Technology, Pune.

Guide: Prof. Dr. Mukundkumar Nalawade

Group ID: D02

Vivek Sanap (07)

Aarya Sangle (08)

Sanket Lavalekar (09)

Arya Sapre (10)

Shrinivas Saraf (11)