Month: October 2015

Stirling Engine

Robert Sterling invited the sterling engine in 1816. It uses the Sterling Cycle, which is different is from the cycles found in internal-combustion engines. Inside the engine, there are no exhaust valves, no explosions taking place and no gasses leaving. The cycle can be powered by any source of heat, from gasoline to coal to decaying plants. Currently, sterling engines are a rarity but scientist are working on developing a mass-market use for the engine.

If you have a cylinder with gas inside and you compress it (decrease the volume of its space), the temperature of that gas will increase. Also, if you have the same amount of gas and you raise the temperature instead of compressing it, its pressure will increase. These concepts are crucial when explaining how the sterling engine works. There are 4 parts to the cycle:

1. Heat is added to the gas inside the left cylinder (heated), which causes pressure to build and the piston to push down.
2. Both pistons work in sync so while the left piston moves down, the left piston moves up which pushes the gas into a right cylinder (cooled). When the gas is cooled, its pressure is lowered which makes it easier to compress.
3. The piston in the right cylinder compresses the gas and generates heat, which is removed by whatever cooling source there is.
4. As the left piston moves down, the right piston moves up. Which pushes the gas into the left cylinder (heated) where it builds pressure and this is when the cycle repeats.

 

The Peltier effect

Discovered by French physicist Jean-Charles Athanase Peltier, it is an effect whereby heat is emitted or absorbed when an electric current passes across a junction between the two materials. In other words, the Peltier effect is a temperature difference that is created by Appling electricity between two electrode that are connected to a sample of semiconductor material which is used to transfer heat.

In the device, the electrodes are made of metal and the semiconductor material creates two junctions between different materials, which, creates a pair of thermocouple voltage which is applies to the electrodes to force electricity through the semiconductor. In general, the devices are used for thermoelectric cooling in electronics and computers

Sources:

https://van.physics.illinois.edu/qa/listing.php?id=19853

https://en.wikipedia.org/wiki/Thermoelectric_cooling

http://searchnetworking.techtarget.com/definition/Peltier-effect

https://www.youtube.com/watch?v=9Cuh2msd2lo

http://auto.howstuffworks.com/stirling-engine1.htmhttps://en.wikipedia.org/wiki/Stirling_enginehttp://www.physics.rutgers.edu/ugrad/351/oldslides/Lecture11.pdf

Tesla is a car brand of the future. The brand currently has two models , the flagship Model S and the newly revealed Model X. Both are all electric, both are fast and both are very expensive.

The key difference between a Tesla and a hybrid is that it is all electric and has to be charged, whereas a hybrid like a Prius does not because it runs partly on gasoline.

How it Works

 

A typical electric motor generates electricity from its magnetic field and winding currents, which are then used to generate force within the motor. The Tesla motor is similar.

The engine consists of two parts, the rotor and the stator and the only points of contact in the motor are the bearings. Each Tesla vehicle has a 3 phase alternating AC motor. The electronics and motor sit on both sides of a single-speed gearbox. Which can take the Tesla up to 130 mph in a single gear.

How to Charge it?

There are a number of ways to charge a Tesla. The company offers a high power wall charger as an option.

This device connects to the back of the car and is able to charge the battery twice as fast as a regular 120-volt outlet could.

Tesla also has plans to install “supercharging” stations all across the United States. These stations will allow drivers to charge their cars in under an hour. Quite Impressive! So far, several stations have already been built and are fully functioning.

Sources:

http://mashable.com/2013/01/17/tesla-electric-car/#HqOeQwBpT5qW

http://www.caranddriver.com/tesla

http://arstechnica.com/features/2013/10/review-tesla-model-s/

http://electronics.stackexchange.com/questions/58236/why-does-a-tesla-car-use-an-ac-motor-instead-of-a-dc-one

Electricity Generation is the process of generating electric power from other sources of primary energy

Coal

 

The coal is grounded into powder which is then blown into a boiler where it is burned. The burning turns its chemical energy into heat energy. Gases are then separated and the burning coal heats water pipes which are coiled around a boiler, which produce steam. Pressure is then used to drive this steam over the blades of a turbine which then spins, creating mechanical energy. Then, the steam is cooled and turned back into water so it can be used again. Lastly, a transformer changes the electricity to a high voltage, which can be used by the national grid.

Natural Gas

 

Natural Gas can be extracted a number of ways. “Blind Extraction” is one method, it is the extraction of liquids and hydrocarbons from the subsurface. The other method is Well Drilling, which is the process of extracting from the subsurface using operating wells

Nuclear  

 

Nuclear power is a very complex method of generating electricity and there is a lot of risk involved in the process but new technology is making nuclear power less risky. Nuclear power uses nuclear reactions to create nuclear energy, which then creates heat. That heat is then transferred to steam turbine which is connected to an electric generator. There, the heat is turned into electricity.

http://www.worldcoal.org/coal/uses-of-coal/coal-electricity/

https://en.wikipedia.org/wiki/Nuclear_power_plant#Future_power_plants

http://www.gazprominfo.com/terms/gas-production/

 

 

What is Fracking?

Fracking is a new technique that is used to recover gas and oil from shale rock. It is done by drilling deep down and then using a high-pressure water, sand and chemical mixture to break the shale rock and release the gas inside.

What are the advantages?

The main advantage of Fracking is that it allows firms to reach oil and gas that was not reachable before. Fracking has greatly reduced the cost of oil and because of that the gas prices all across America have dropped dramatically which is great for the American people.

What are the disadvantages?

Fracking is dangerous forof a number of reasons. First, fracking releases damaging chemicals which is concerning because these chemicals can find their way into the large groundwater supply. Second, fracking uses an unbelievable amount of water, and transporting this water is very expensive. Third, fracking has been associated with causing small earthquakes. These reason have all contributed to the great amount of concern with Fracking. As a result, environmental agencies have been doing everything in their power to slow down the growth of the industry and will continue to do so for as long as they can.

Sources:

http://www.what-is-fracking.com/

http://www.bbc.com/news/uk-14432401

http://www.marketplace.org/topics/sustainability/fracking-firms-face-hard-times

http://water.epa.gov/type/groundwater/uic/class2/hydraulicfracturing/wells_hydrowhat.cfm

https://www.asme.org/engineering-topics/articles/fossil-power/fracking-a-look-back

 

The US energy grid is a network that delivers energy to homes across America. It generates $400 billion of electricity a year, consists of 3,200 utilites and uses 450,000 miles of high –voltage transmission lines to carry electricity from power stations to homes. Currently there are 4 existing lines 245-499 kV, 500-699 kV, 700-799 kV and 1000 kV (DC) and the grid is divided into three major sections which are Eastern, Western and Texas (ERCOT).

Today, hackers are a major challenges faced by the energy grid. In 2014, there were 79 separate attacks alone. Although the hackers rarely damage or disrupt the machines, the fact that their malware has been found in software is worrying because it gives hackers the ability to enter in destructive code that could be damaging in the future.

Sources:

http://www.bloomberg.com/bw/articles/2013-08-22/homegrown-green-energy-is-making-power-utilities-irrelevant

http://www.eia.gov/energy_in_brief/article/power_grid.cfm

https://en.wikipedia.org/wiki/Electrical_grid