Engineering and Thermodynamics: Paired Work For Better Surrounding

Thermodynamics coupled with fluid mechanics has had a profound effect on how we function as a species. The understanding and insight gained through scientific study of these fields has enabled us to effectively manipulate our surrounding. Engineers have applied this knowledge to create mechanical machines, such as cars and farming equipment, optimise many systems to improve their efficiency and create new technology, which have transformed societies and continues to change our way of life.

So, what is thermodynamics? According to Britannica 'Thermodynamics is the study of the relations between heat, work, temperature, and energy. The laws of thermodynamics describe how the energy in a system changes and whether the system can perform useful work on its surrounding'. The name is derived from two Greek words: 'thermes' meaning Heat and 'dynamikos' meaning powerful or force. This illudes to one of the early uses of the application of thermodynamics, the steam engine.

Thomas Savery was a man who invented the first successful water pump in 1698, which in his own words was an 'engine to raise water by fire'. This first water pump helped to drain mines, creating the opportunity to reopen flooded mines, and removing the need for the older 'bucket lift' driven by horses. It was a based off a very basic steam engine which passed steam into a vessel, the vessel was then isolated from the steam supply and cooled creating a vacuum which pulled a piston down. This would draw water up into the vessel due to the vacuum. Though this was a revolutionary machine at the time, it was not very efficient and resulted in several boilers exploding. It does illustrate the basic principles of thermodynamics and fluid mechanics. The law of conservation of energy: showing that energy can be converted from one form into another but is always conserved. Matter can be burnt to release its energy and create heat which can then be converted into kinetic energy or the movement of the piston and then into potential energy or the energy gained by the water as it is lifted. The second law of thermodynamics: that two bodies will tend to thermal equilibrium over time, or in this case the steam losing its energy to the environment. The ideal gas law: pressure and volume of an ideal gas are proportional to its temperature. This principle was used in the creation of steam which takes up a large volume and has a high pressure when hot but shrunk and exerted less pressure on its surrounding when cooled, creating a vacuum. These properties were understood but clearly not controlled well enough, given the explosion of the boilers.

Jump forward to the twenty first century, and heat and flow are a critical part of many engineering fields. Steam has been converted into electrical energy to power much of the modern era. One such example is in nuclear power plants.

According to the websites Nuclear-power.com and energy.gov a Nuclear Power Plant is a thermal power plant comprising of two parts: a 'nuclear island' and a 'conventional island'. The nuclear island houses the reactor core in which the nuclear fuel undergoes nuclear fission; a process where atoms split through neutron multiplication and a chain reaction occurs releasing large quantities of energy, typically being about 3400MW of thermal power. This heat is transferred into the primary coolant loop as it flows around the core, reaching temperature of approximately 290-325 degree C. The coolant is then pumped into steam generators and the heat is transferred through the pipes into the secondary coolant loop, evaporating the coolant in the secondary loop and creating pressurised steam at about 280degree C and 6.5MPa. The nuclear island also contains control infrastructure necessary to monitor and maintain all the critical systems ensuring the safety of the plant.

In conclusion, though the physical restraints of the world we live in, have always remained the same, the complexity, scale and ambition of projects being undertaken by Engineers has grown enormously, being driven by the human desire to invent and overcome new challenges. Heat and flow are an intrinsic part of almost all these projects, providing the knowledge necessary to overcome many of the challenges and the ability to quantify the efficiency of a chosen solutions in comparison to an idealistic system. The role of the thermodynamics and fluid mechanics fields is to be a tool to help show and understand the constraints of our environment and how effectively we can work within them.