Why Stirling Engines Can Also Serve As Energy Storage Systems

engines have powered our world since the industrial revolution first the dirty coal powered steam engine then the cleaner and more efficient gasoline engine and more recently the jet engines which are used in airplanes the basic concept of an engine something that uses the difference between high and low temperatures has not changed for several hundred years although sometimes minor improvements can still be found that make the process slightly faster or more efficient one engine that you may have heard a lot about these days is the sterling engine which is a bit like a steam engine that doesn't use steam instead it heats cools and recycles the same air or gas over and over again to create useful energy that can power an engine combined with solar technology and other emerging technologies the sterling engine sounds like cutting edge technology but it's actually been around since 1816. let's take a closer look at how it works and how it can be used as an energy storage system the history and production of the sterling engine it is not surprising that the sterling engine was invented in 1816 by a scottish priest named robert sterling he hoped to build an engine that was safer and more efficient than the steam engine developed by thomas newcomen about a century ago and later improved by james watt and others the advent of the internal combustion engine left the sterling engine behind although it was rediscovered by philips in the mid 20th century recently they have become popular in solar power generation and other forms of renewable energy where their higher efficiency is appreciated this technology got another boost in the 1980s when ivo colin of the university of zagreb and james semf of the university of wisconsin developed a new very compact design for a sterling engine that could generate power with only a small difference between the heat source and the sink the original sterling engine was invented and patented by robert sterling on september 27 1816 and was first used in 1818 as a pumping device to force water into mines although it was based on the earlier attempts to produce air engines it was the first to be put into practice in 1992 professor sempt was asked to design and build a cryogenic engine for nasa this engine called the n92 was optimized for manual operation with a temperature difference of six degrees celsius sufficient to power it professor semt continues to work with the sterling engine and has written several books detailing the history and production of the sterling engine what problems were we facing with the steam engine there are many problems with steam engines but here are four of the more obvious ones first boilers that produce steam operate at high pressure and are in danger of exploding boiler explosions were a big problem with very early steam engines second boilers have usually located at some distance from the store so energy is lost when heat is transferred from one point to another third the steam coming out of the smoke stack is still hot enough so it contains lost energy fourth the engine must use a lot of water and fuel because each time the piston is pushed steam is expelled from the cylinder this is why the steam locomotive had to stop at a water tank at the edge of the track how does the sterling engine improve on a steam engine what is the working principle of the sterling engine can we design an engine that solves all those four problems suppose we get rid of the boiler which would eliminate the risk of explosion and use the heat from the fire to start the engine directly instead of using steam to transport heat from the flames to the cylinders why not place the cylinders closer to the flames and use ordinary air or some other simple gas to transfer the heat between them that's why a sterling engine is sometimes called a hot air engine if we can find this air in a closed tube the same air constantly moves back and forth extracting energy from the fire and releasing it into the cylinders we solve the problem with an engine that always needs water finally why not add some form of heat exchanger so that the energy in the hot air as it moves back and forth is retained and recycled within the engine to improve overall efficiency this was the primary way the sterling engine improved the steam engine sometimes you'll see sterling engines referred to as closed cycle regenerator of heat engines which is a very short way of saying what we just said closed cycle means they use a closed volume of gas to move heat forward to move backward and forward again through a series of endlessly repeated steps regenerative means they use heat exchangers to retain some of the heat that would otherwise be lost in each cycle the sterling engine is a simple and easy to manufacture engine that can be operated with almost any heat source even at relatively low levels it is a type of external combustion engine that converts heat energy into kinetic energy by heating and cooling the working gases trapped in the cylinder the thermal efficiency of the sterling cycle is as high as the carnot cycle which theoretically has the highest thermal efficiency fuel combustion takes place continuously so controlling exhaust emissions is quite easy the basic key principle of the sterling engine is that a fixed amount of gas is sealed inside the engine a sterling engine is an external combustion engine because heat is added to the air inside the engine from a source outside the cylinder rather than being added by burning the fuel inside the cylinder sterling engines have low noise and vibration potential due to smooth cyclic torque fluctuations due to non-explosive combustion the aim of this development is to increase durability and reduce the cost of components exposed to high temperatures and pressures for example above 10 mpa is the system of sterling engine simple or complex some people say that the sterling engine is simple if this is true it is also true that the great equations of physics such as e equals m c squared are simple simple on the surface but richer more complex and potentially very confusing if you don't really understand them i think it's safer to think of sterling engines as complicated i don't think you can understand a sterling engine simply by building it or observing how it works from the outside you have to think carefully about the cycle of steps it goes through what happens to the gases inside and how it feels different from what happens in a regular steam engine anyway let's see if we can properly explain the sterling engine by first looking at the parts inside then thinking about what they do key parts of the sterling engine there are several different sterling engine designs and we will look at the specific type known as the displacer sterling engine also known as the beta sterling engine these are the most important parts number one heat source the heat source is where the engine gets all of its energy and can be anything from coal fire to a solar mirror that concentrates heat from the sun although referred to as external combustion engines sterling engines are not intended to use combustion at all they simply require a temperature difference between the heat source where the energy comes from and the radiator where it ends up you can drive a tiny sterling engine with the heat of a cup of coffee the warm palm of your hand or even to the surprise of many an ice cube the energy released by the engine comes from the temperature difference between the heat source and the radiator however it should be born in mind that a small sterling engine powered by something like a cup of coffee can do a lot of work simply because it contains a small amount of energy that is used up very quickly number two gas inside the engine there is a volume of gas that is permanently sealed in a closed cylinder this can be ordinary air hydrogen helium or some other readily available substance that remains a gas as it heats up and cools down throughout the engine cycles a series of repeated events through which it goes its sole purpose is to transfer thermal energy from the heat source to the radiator move the pistons that dried the engine and then return to take in more the gas that drives the heat is sometimes called the working fluid number three a place where hot gases are cooled before being returned to a heat source this is usually a radiator that has a piece of metal with fins attached that emits waste heat into the atmosphere number four pistons these are rigid cylindrical pistons used in the cylinders and are responsible for the final performance of the engine depending on the sterling engine type be it alpha or beta one or two pistons are used two pistons are used for alpha sterling engines and one piston is used for beta sterling engines number five heat exchanger also known as a regenerator a heat exchanger is located in an enclosed space between the heat source and the coolant or heat sink as the hot gas moves through the regenerator it gives off some of the heat that the regenerator retains as the gas moves back it absorbs the heat yet again without a regenerator this heat would be lost to the atmosphere and wasted the heat exchanger greatly improves the efficiency and performance of the engine some sterling engines have multiple heat exchangers applications and uses of sterling engines and how they can be used as energy storage systems they are renowned for their potential to be more efficient than gas or diesel engines or even as an alternative source of clean fuels but they are currently only used in very specific and specialized applications the sterling engine can use the exhaust heat from a natural gas generator as a heat source to generate mechanical energy this is something you can find in the industrial and agricultural industries in one application the machine focuses on parabolic mirrors to convert solar energy into electricity such as the 1.5 megawatt maricopa solar power plant installed in arizona which achieves 31 percent efficiency but it is the use of the sterling engine and its highly efficient conversion of heat to mechanical energy that can offer other great storage options swedish company azealio already a leading provider of sterling engine based renewable energy solutions is now focusing on distributed and available solar power using sterling engines for thermal energy storage tes in a tes system thermal energy is stored by heating or cooling material so that the stored energy can later be used for either heating and cooling applications or power generation depending on the technology energy can be stored and used for hours days or even months helping to manage seasonal fluctuations in energy supply and demand concentrated solar power plants are the most common application of tes where storage allows them to distribute electricity 24 7. the primary storage technology used is molten salt thermal storage accounting for 75 percent of tes in 2017 but azealio developed a different approach the technology combines sterling technology with tes powered by a solar photovoltaic system or wind generator this technology is capable of providing 13 hours of clean and reliable power for continuous operation in addition azealio technology requires no replacement and downtime with an incredible 30 years of service life although sterling engines are most commonly used today to power submarines auxiliary power generators large-scale solar energy or as small models and toys they have the potential to be developed for use in much larger and more successful markets if the proper research is able to be applied keep an eye the future of technology is here with this wonderful energy storage system

Channel: The Tesla Domain

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Keywords: tesla, elon musk, tesla news, cybertruck, model y, model 3, spacex, tech, EV, model s, model x, the tesla domain, top, best, new, stirling engine, stirling engine generator, stirling engine how it works, stirling engine review, stirling engine energy storage, stirling engine as energy storage system, azelio stirling engine, azelio thermal storage, thermal storage, thermal storage tank, thermal energy, thermal energy storage, thermal energy storage system

Id: F2amXKKsBmQ

Length: 12min 1sec (721 seconds)

Published: Tue Mar 22 2022