"Wisdom begins in wonder" – Socrates
Tag: Chemical Engineering
Industrial Control Systems
10/26/17
“How can we control industrial processes?”
In Industrial operations, we often have to deal with large-scale control systems along with their instrumentation. Because of this, we will need to develop various types of special control systems to monitor and process everything. These constructions are known as industrial control systems and are one of the major underpinnings of modern-day industry.
Why Lithium-ion Batteries are Better for Renewable Energy Integration
10/11/17
“What is one possibility to solve renewable energy storage?”
Subject Solar Energy / Storage Innovations
Date: October 11, 2017
Purpose
I am writing to you to inform you about recent difficulties in solar energy integration. As it stands, solar energy is generated in an active form, meaning that once created it must be used immediately. To solve this, we can deploy Lithium-ion batteries to act as reservoirs.
Summary
Lithium-Ion Batteries have properties that make them a strong option for renewable energy integration. Lithium-ion batteries are composed of lithium and carbon, giving them special characteristics. However, these same properties also give Lithium-Ion Batteries special problems, such as being prone to spontaneous explosions. (Brain, 2006)
Background
One of the major bottlenecks to renewable energy integration is a lack of viable storage mechanisms. One of the most viable solutions, battery systems, has numerous drawbacks. They can take up large amounts of space, and provide a low energy to space ratio. Consequentially, the current battery technology paradigm needs to be overhauled.
Discussion
Introduction
Lithium-Ion Battery Technologies are a new battery technology. Because of their unique properties, they hold much potential for Renewable Energy Storage. However, this same composition that makes it special also makes it potent for mishap.
Advantages
Lithium-ion Batteries include numerous advantages. Their much more energy dense, meaning that a small volume can hold a lot of charge, bypassing the previous space issue. They also tend to keep this charge, losing only 5%/month compared to the average 20%/month, allowing renewable energy to be stored for a longer time. They also can also be charged before they run out of power and can handle hundreds of charge/discharge cycles, making them quite viable for being used as battery storage with the dynamic character of renewable energy. (Brain, 2006)
Drawbacks
These batteries also come with numerous drawbacks. They start degrading once manufactured, decay faster in the presence of high temperatures, are ruined upon complete discharge, require an onboard control system, and most importantly, may burst into flame spontaneously if it overheats. (Brain, 2006)
How we can overcome this
Keep these batteries in low-temperature facilities. This will keep their charge more stable, have it degrade slower, and most importantly prevent spontaneous explosions.
Conclusion
Even with their flaws, Lithium-ion technology holds much potential for use in renewable energy integration. Their high energy density combined with their ability to handle dynamics charging and discharging gives them an unparalleled capacity to work with renewable energy. If we can store them in colder locations, then we can also greatly reduce their drawbacks.
References
Brain, Marshall. “How Lithium-Ion Batteries Work.” How Lithium-Ion Batteries Work | HowStuffWorks, HowStuffWorks, 14 Nov. 2006, electronics.howstuffworks.com/everyday-tech/lithium-ion-battery.htm.
Dead Reckoning
08/17/17
“How can we make a location history using past velocities?”
Making a location history can be very difficult. Having to make active GPS measurements for a cycle of intervals is very taxing on resources. However, is there a way that we could circumvent this and make a new less resource intense system? Well, let’s start off by thinking back to basic physics. We know that velocity multiplied by time equals a change in distance. So what if were to start off with an initial GPS location and then build an array of all of the measured velocities after that? Well, this is the fundamental ideas behind a technique known as Dead Reckoning and is commonly implemented in control systems and machines that are equipped to go into no-GPS locations.
Integral Control
08/17/17
“How can control systems be based on the summation of error levels over time?”
Control systems respond to an error between feedback and setpoints by making changes to the next output. However, sometimes the error does not change fast enough or it changes too quickly. So how could we devise a mechanism to solve this issue? Well, let’s start with a simple idea. We know that if an error value were to persist over time it would show easily on a graph. So what if we were to just take the area of the error under this graph and modify our outputs accordingly? This is the fundamental idea behind integral control and is one of the prime factors in the ever so often used PID control system.
Derivative Control
08/16/17
“How can control the rate of change of our control system?”
Proportional control systems are great for correcting the error of simple applications. However, one major drawback is that this method does not control the rate of change of the control system. For example, let’s say that we have a self-driving car that needs to accelerate to the speed limit of a roadway. Proportional Control might accelerate so fast that it actually overshoots the speed limit and causes an accident! To solve this, we can introduce a factor called a derivative control which modulates the rate of change of the system. If we were to introduce it to the self-driving car, then its rate of change would be held in a sustainable manner and decrease to zero as it becomes closer to the setpoint.
Part-load efficiency
08/15/17
“Can machines operating at part loads have different efficiencies than full loads?”
Machines can operate at variable loads. For example, an electric grid might be providing electricity to its entire network during the daytime and only a few houses at night. Because these different loads have different parameters, machines operating at partial loads have something called a part-load efficiency, or the efficiency when not at full (100%) loading.
Contour of model predictive control
08/04/17
“How can we predict how a system will react based on how it reacts right now?”
When working with control systems, we often have some desired output in our mind. However, frequently the actual performance of our systems diverges greatly from what we want. So how can we use our engineering mindset to correct this problem? Well, let’s think about it. We can tell a computer how we want a certain system to behave. And we can also create a log of its outputs. So what if every time we gave an output, we took its data, compare it to our desired, and try to minimize the difference with the next iteration? Well, this is the fundamental idea behind model predictive control and is used in industries spanning from building controls to renewable energy to intelligent transportation systems!
Shell and tube heat exchanger
07/31/17
“What is the most popular type of heat exchanger?”
Let’s think of a design for a simple heat exchanger. First, let’s take a bundle of tubes and put it into a shell. Then, let’s run one fluid through the tubes and another around the tubes, both at different temperatures. Over time, the heat from the hotter one to the colder one. This setup is known as a shell and tube heat exchanger. Shell and tube heat exchangers come in two varieties, single phase (which have the fluids in only one phase) and multiphase (which uses both gases and liquids simultaneously). Because of their simple construction, shell and tube heat exchanger have become the most popular in the world.
Solar paint
07/01/17
“Can we use paint to make energy?”
Paint is usually seen as just a covering used to keep mold away or for making art. However, is it possible to do more with this material? Well, let’s analyze this using our scientific mindset. If we were to mix in titanium oxide into paint, then it would be capable of absorbing sunlight to convert the moisture into hydrogen and oxygen, therefore allowing for the consumption of hydrogen energy. This tecnology is currently being developed by a team at RMIT in Australia and could revolutionize sustainable energy generation, allowing for easy residential level consumption!
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