Jump to content
Science Forums

Can Steam Replace The Internal Combustion Engine ?


scotter59

Recommended Posts

Here is a company that seems to be developing a steam solution Cyclone - modern steam engine.. and this pdf whitepaper on the modern steam engine in an automobile.

 

As is stated in the white paper by James D. Crank steam has been a contender for centuries as a mode of transportation, the technology was not there to make it as effective as the Internal Combustion was. The technology is now available and with the EATR robot in the works.....

 

Have a petition here, I would not like to see this idea be bought up by some automobile corporation and shelved. Personally it would be nice to have a power source that is less complex, more adaptable than the current internal combustion engine.

Link to comment
Share on other sites

Here is a company that seems to be developing a steam solution Cyclone - modern steam engine.. and this pdf whitepaper on the modern steam engine in an automobile.

 

As is stated in the white paper by James D. Crank steam has been a contender for centuries as a mode of transportation, the technology was not there to make it as effective as the Internal Combustion was. The technology is now available and with the EATR robot in the works.....

 

Have a petition here, I would not like to see this idea be bought up by some automobile corporation and shelved. Personally it would be nice to have a power source that is less complex, more adaptable than the current internal combustion engine.

 

I do not know much about that but I have heard that some bright scientist are working on something called electricity, if that is true we might see first cars equipped with electric motors in coming 50 years or so. Yes I know, it might sound science fiction but I have gut feeling that it might happen...

Link to comment
Share on other sites

Here is a company that seems to be developing a steam solution Cyclone - modern steam engine.. and this pdf whitepaper on the modern steam engine in an automobile.

 

As is stated in the white paper by James D. Crank steam has been a contender for centuries as a mode of transportation, the technology was not there to make it as effective as the Internal Combustion was. The technology is now available and with the EATR robot in the works.....

 

Have a petition here, I would not like to see this idea be bought up by some automobile corporation and shelved. Personally it would be nice to have a power source that is less complex, more adaptable than the current internal combustion engine.

Very interesting engine. I can imagine that if it had come before the internal combustion engine it may be the standard we see today. I am curious about the power to weight ratio that you get and the fuel efficiency.

 

Bill

Link to comment
Share on other sites

It would seem that at around the begining of the last century steam and electric cars were doing quite well compared to ICE cars.

 

http://en.wikipedia.org/wiki/Electric_car

 

Acceptance of electric cars was initially hampered by a lack of power infrastructure, but by 1912, many homes were wired for electricity, enabling a surge in the popularity of the cars. At the turn of the century, 40 percent of American automobiles were powered by steam, 38 percent by electricity, and 22 percent by gasoline. 33,842 electric cars were registered in the United States, and the United States of America became the country where electric cars had gained the most acceptance. Sales of electric cars peaked in 1912.

 

http://en.wikipedia.org/wiki/History_of_the_electric_vehicle

 

Electricity is one of the oldest automobile propulsion methods still in use today; it predates the invention of Diesel's and Benz's Otto cycle-engines by several decades.

 

The invention of the electric vehicle is attributed to various people. In 1828, Ányos Jedlik, a Hungarian who invented an early type of electric motor, created a tiny model car powered by his new motor.[1] In 1834, Vermont blacksmith Thomas Davenport, the inventor of the first American DC electrical motor, installed his motor in a small model car, which he operated on a short circular electrified track.[2] In 1835, Professor Sibrandus Stratingh of Groningen, the Netherlands and his assistant Christopher Becker created a small-scale electrical car, powered by non-rechargeable primary cells.[3] In 1838, Scotsman Robert Davidson built an electric locomotive that attained a speed of 4 mph (6.4 km/h).[4] Between 1832 and 1839, Robert Anderson of Scotland invented a crude electrical carriage.[1][5] A patent for the use of rails as conductors of electric current was granted in England in 1840, and similar patents were issued to Lilley and Colten in the United States in 1847.[6] Rechargeable batteries that provided a viable means for storing electricity on board a vehicle did not come into being until the 1840s.[citation needed]

 

The idea that a steam engine can run on any fuel is little bit misleading, kind of like saying a ICE will run on anything, an ICE can run on coal dust theoretically, the engine has to be prepped for certain fuels to be usable, you can't load cord wood into this engine any more than you could load coal dust into your average ICE but the idea of steam may eventually be an idea whose time has come but it will take quite a bit to tear the ICE out of our cars...

Link to comment
Share on other sites

I do not know much about that but I have heard that some bright scientist are working on something called electricity, if that is true we might see first cars equipped with electric motors in coming 50 years or so. Yes I know, it might sound science fiction but I have gut feeling that it might happen...

 

 

Wow ELECTRICITY did not think of that......

 

How are the copper and lithium supplies ? How many people ? How about the load on the grid to support people charging their lithium batteries ? Have a good fuel supply to power the grid - maybe Polywell or the Fusor will get fired up ? Maybe we could follow Tesla's research on wireless energy transmission using the Schumann resonance cavity - good luck on getting the money men to invest in that.

 

Was just watched a show on the History Channel called the "Universe" where they discussed solar flares and the effect a direct hit would have on our technology, specifically electric - think I would want to have an alternative. This steam engine would be able to charge my "electric", power my house off of wood chips, gasoline or algae....... enjoy the grid, while it lasts.

Link to comment
Share on other sites

Wow ELECTRICITY did not think of that......

 

How are the copper and lithium supplies ? How many people ? How about the load on the grid to support people charging their lithium batteries ? Have a good fuel supply to power the grid - maybe Polywell or the Fusor will get fired up ? Maybe we could follow Tesla's research on wireless energy transmission using the Schumann resonance cavity - good luck on getting the money men to invest in that.

 

Was just watched a show on the History Channel called the "Universe" where they discussed solar flares and the effect a direct hit would have on our technology, specifically electric - think I would want to have an alternative. This steam engine would be able to charge my "electric", power my house off of wood chips, gasoline or algae....... enjoy the grid, while it lasts.

 

It is interesting to see how much there is resistance :) towards electric car development. My personal opinion is that the old combustion motor technology was/is supported by the "oil barons" and any competitive technology development should not be supported in bigger scale. From my perspective there is no really any other good explanation why this electric car concept has not developed any great lengths. Moontanmans post indicated that is not due that we have not known the technology itself enough long time. Just no major research funding to certain field and things stop or slow down radically.

 

Currently I would see the power for electric cars coming from these different sources

 

-Batteries

-Inductive charging

-Solar cells

-Any other power cell technology which could be efficiently transferred to electric power "on board"

 

In 2006, researchers at the Massachusetts Institute of Technology reported that they had discovered an efficient way to transfer power between coils separated by a few meters. The team, led by Marin Soljačić, theorized that they could extend the distance between the coils by adding resonance to the equation. The MIT wireless power project, called WiTricity, uses a curved coil and capacitive plates.[7][8]

 

And Boeing’s new 787 Dreamliner, scheduled to be delivered to customers in 2010, requires about 6.5 million lines of software code to operate its avionics and onboard support systems.

 

These are impressive amounts of software, yet if you bought a premium-class automobile recently, ”it probably contains close to 100 million lines of software code,” says Manfred Broy, a professor of informatics at Technical University, Munich, and a leading expert on software in cars. All that software executes on 70 to 100 microprocessor-based electronic control units (ECUs) networked throughout the body of your car.

 

http://news.discovery.com/tech/toyota-recall-software-code.html

 

But fair enough, your post was concernig steam so I do not interrupt your quest more than this.

 

All the best.

Link to comment
Share on other sites

It is interesting to see how much there is resistance :) towards electric car development. My personal opinion is that the old combustion motor technology was/is supported by the "oil barons" and any competitive technology development should not be supported in bigger scale. From my perspective there is no really any other good explanation why this electric car concept has not developed any great lengths. Moontanmans post indicated that is not due that we have not known the technology itself enough long time. Just no major research funding to certain field and things stop or slow down radically.

 

Currently I would see the power for electric cars coming from these different sources

 

-Batteries

-Inductive charging

-Solar cells

-Any other power cell technology which could be efficiently transferred to electric power "on board"

 

 

 

 

 

http://news.discovery.com/tech/toyota-recall-software-code.html

 

But fair enough, your post was concernig steam so I do not interrupt your quest more than this.

 

All the best.

 

As I understand it, the big probs facing electric cars and their acceptance right now are the limitations of batteries, such as their weight, storage capacity, cost, etc. and the use of rare earth metals in things like the batteries, motors, etc., because China is the world's main exporter of those and is decreasing exports of those, which of course increases the cost of electric motors and batteries that need them. Gasoline and diesel are amazingly energy rich and energy dense for their weight and volume. Though combustion engines tend to be very inefficient, they're versatile and attached to a large enough energy reserve (gas/diesel) that for most people it doesn't matter that they could be better, but only that the technology and range are good enough right now.

 

My hope is not for an all-electric, but an NG or liquid-fuel/electric hybrid, and probably one that would take the best of both electric motors and generator/combustion technology. Combustion engines still have unparalleled flexibility, development, and use behind them. Steam engines are very good, and probably would be great in cars again. I've spent a lot of time reading and thinking about it. Steam engines have the advantage of generally being more efficient than gasoline combustion engines and providing huge amounts of torque at low RPM. However, there are several other technologies that give it a good run for its money (like electric motors, turbines?) and even combustion technology, it appears, can be improved greatly. I think the focus has been more on power than efficiency in the car world. It takes things like high fuel prices or shortages to get people to make efficiency a priority again.

Link to comment
Share on other sites

Combustion engines still have unparalleled flexibility, development, and use behind them. Steam engines are very good, and probably would be great in cars again. I've spent a lot of time reading and thinking about it. Steam engines have the advantage of generally being more efficient than gasoline combustion engines and providing huge amounts of torque at low RPM. However, there are several other technologies that give it a good run for its money (like electric motors, turbines?) and even combustion technology, it appears, can be improved greatly. I think the focus has been more on power than efficiency in the car world. It takes things like high fuel prices or shortages to get people to make efficiency a priority again.

 

 

Is there direct comparison concerning different motor structures, weight, size, efficiency, simplicity/reliability of the structure, environmental factors, drivability, torque etc..?

 

For example how many moving parts do you need in electric motor itself compared to any other motor concept currently?

Link to comment
Share on other sites

It is interesting to see how much there is resistance :) towards electric car development. My personal opinion is that the old combustion motor technology was/is supported by the "oil barons" and any competitive technology development should not be supported in bigger scale. From my perspective there is no really any other good explanation why this electric car concept has not developed any great lengths. Moontanmans post indicated that is not due that we have not known the technology itself enough long time. Just no major research funding to certain field and things stop or slow down radically.

 

Currently I would see the power for electric cars coming from these different sources

 

-Batteries

-Inductive charging

-Solar cells

-Any other power cell technology which could be efficiently transferred to electric power "on board"

 

 

 

 

 

http://news.discovery.com/tech/toyota-recall-software-code.html

 

But fair enough, your post was concernig steam so I do not interrupt your quest more than this.

 

All the best.

 

Not resistance to electric cars, just sounds like trading a dependence on oil to one on lithium or "high" tech.

I was hoping that EStor would be successful with their capacitor idea, if it had any foundation.

 

If what is being said about the Cyclone's engine is correct it would be able to use a larger variety of fuels than any ICE.

 

This would be ideal for developing nations who may not be able to afford a power plant or had a problem getting fossil fuels to remote areas but might be able to collect methane, distill alcohol ... course it depends on the cost to build and deliver to the consumer. I was thinking of farmers also, consider they might have the roughage to make their own fuel cutting costs.

 

Solar cells, batteries and other alternate power sources need to evolve, steam is an old concept with new technology and greater fuel sources that can be done in the near future.

 

Basically am just tired of this dependence, if I can distill some alcohol, tap into some swamp gas, run a designed engine that would give me electric for my electronics and power for transportation I can give the oil companies the ..... well ..... and unlike the Tesla or the hybrids I might be able to replace a part.

Link to comment
Share on other sites

Is there direct comparison concerning different motor structures, weight, size, efficiency, simplicity/reliability of the structure, environmental factors, drivability, torque etc..?

 

For example how many moving parts do you need in electric motor itself compared to any other motor concept currently?

 

I suggest scanning Wiki's page on the internal combustion engine:

 

http://en.wikipedia.org/wiki/Internal_combustion_engine

 

Since it covers so many different types and designs, it will provide a good overview of what currently exists and some things being explored. Motor structures and designs can vary wildly, as can weight and size and reliability. There's a wide, wide variety in what's out there and being worked on right now.

 

For example, Wankel engine has fewer moving parts and delivers excellent smooth high RPM and power from its compact size, but its reliability due to wear and intake of some fuels can be limited. They tend to wear out faster than most other internal combustion engines. That said, Mazda's still a big fan of Wankel engines.

 

Wankel engines are considerably simpler, lighter, and contain far fewer moving parts than piston engines of equivalent power output. For instance, because valving is accomplished by simple ports cut into the walls of the rotor housing, they have no valves or complex valve trains; in addition, since the rotor rides directly on a large bearing on the output shaft, there are no connecting rods and there is no crankshaft. The elimination of reciprocating mass and the elimination of the most highly stressed and failure prone parts of piston engines gives the Wankel engine high reliability, a smoother flow of power, and a high power-to-weight ratio.

 

Electric motors offer many of the best advantages and few of the disadvantages of other motors, but the problem is more in rare resources needed to make one (like neodymium or other rare earths) and the ability to power an electric motor (i.e., battery limitations). As far as I know, they offer the best combination of power, efficiency, compactness, and size. However, they are obviously not fuel flexible. This can be ameliorated by using an electric motor in a hybrid vehicle, so that you have fuel flexibility by converting fuel --> electricity.

 

http://en.wikipedia.org/wiki/Brushless_DC_electric_motor

http://en.wikipedia.org/wiki/AC_motor

 

I'm not an expert in this, but I have done enough reading on different kinds of engines and motors to get a good sense of what works and doesn't. The internal combustion engine's flexibility, reliability, and proven power have been shown time and time again through World Wars, vehicles for transportation, etc. and it has the greatest amount of development behind it. That said, it's also inefficient and wastes most of the fuel's energy as heat and needs redesigning for a 21st-century world where energy and resources are going to be increasingly limited. We can't afford engines that only can extract 20-30% of the energy they get from gas or diesel and waste the rest as heat and pollution.

 

http://ffden-2.phys.uaf.edu/102spring2002_web_projects/z.yates/zach%27s%20web%20project%20folder/eice%20-%20main.htm

 

The advantages of a steam engine are listed by Wiki as well:

 

http://en.wikipedia.org/wiki/Steam_engine#Advantages

 

My hope again is for a hybrid vehicle that can take advantage of liquid fuel strengths (high energy capacity + density), convert that fuel into electrical power, and use that to run electric motors, which are among the best for power and efficiency.

Link to comment
Share on other sites

My hope again is for a hybrid vehicle that can take advantage of liquid fuel strengths (high energy capacity + density), convert that fuel into electrical power, and use that to run electric motors, which are among the best for power and efficiency.

 

 

This is very "wide topic" no easy answers available but my personal view is that so big revenues are linked to this current motor technology and oil itself that no rapid changes are expected. Money comes first, then....big gap and technology, environment and natural resources considerations

Link to comment
Share on other sites

Here is a company that seems to be developing a steam solution Cyclone - modern steam engine.. and this pdf whitepaper on the modern steam engine in an automobile.

 

As is stated in the white paper by James D. Crank steam has been a contender for centuries as a mode of transportation, the technology was not there to make it as effective as the Internal Combustion was. The technology is now available and with the EATR robot in the works.....

 

Have a petition here, I would not like to see this idea be bought up by some automobile corporation and shelved. Personally it would be nice to have a power source that is less complex, more adaptable than the current internal combustion engine.

Rankine Cycle is a very interesting way in building new highly efficient thermal machines defined as "isoentropic" machines in which the power is tranferred from a combustion chamber to conventional turbines without losses in temperature of the primary fluid). From wikipedia:

 

Organic Rankine Cycle

 

 

 

 

 

The Organic Rankine cycle (ORC) is named for its use of an organic, high molecular mass fluid with a liquid-vapor phase change, or boiling point, occurring at a lower temperature than the water-steam phase change. The fluid allows Rankine cycle heat recovery from lower temperature sources such as industrial waste heat, geothermal heat, solar ponds etc. The low-temperature heat is converted into useful work, that can itself be converted into electricity. A prototype was first developed and exhibited in 1961 by Israeli solar engineers Harry Zvi Tabor and Lucien Bronicki.

 

Contents

 

 

 

 

 

* 1 Working principle of the ORC

 

* 2 Improvement of the organic Rankine cycle

 

* 3 Applications for the ORC

 

* 4 Choice of the working fluid

 

* 5 See also

 

* 6 References

 

 

 

Working principle of the ORC

 

T-s diagram for the ideal/real ORC

 

 

 

The working principle of the organic Rankine cycle is the same as that of the Rankine cycle : the working fluid is pumped to a boiler where it is evaporated, passes through a turbine and is finally re-condensed.

 

 

 

In the ideal cycle, the expansion is adiabatic and isentropic and the evaporation and condensation processes are isobaric.

 

 

 

In the real cycle, the presence of irreversibilities lowers the cycle efficiency. Those irreversibilities mainly occur :

 

* During the expansion : Only a part of the energy recoverable from the pressure difference is transformed into useful work. The other part is converted into heat and is lost. The efficiency of the expander is defined by comparison with an isentropic expansion.

 

* In the heat exchangers : The working fluid takes a long and sinuous path which ensures good heat exchange but causes pressure drops that lower the amount of power recoverable from the cycle.

 

Improvement of the organic Rankine cycle ORC with Regenerator

 

 

 

In the case of a "dry fluid", the cycle can be improved by the use of a regenerator : Since the fluid has not reached the two-phase state at the end of the expansion, its temperature at this point is higher than the condensing temperature. This higher temperature fluid can be used to preheat the liquid before it enters the evaporator.

 

 

 

A counter-current heat exchanger is thus installed between the expander outlet and the evaporator inlet. The power required from the heat source is therefore reduced and the efficiency is increased.

Applications for the ORC

 

The organic Rankine cycle technology has many possible applications. Among them, the most widespread and promising fields are the following:

 

* Waste heat recovery B)

 

Waste heat recovery is the most important development field for the Organic Rankine Cycle (ORC).[citation needed] It can be applied to heat and power plants (for example a small scale cogeneration plant on a domestic water heater), or to industrial and farming processes such as organic products fermentation, hot exhausts from ovens or furnaces, flue gas condensation, exhaust gases from vehicles, intercooling of a compressor, condenser of a power cycle, etc.[2]

 

* Biomass power plant

 

Biomass is available all over the world and can be used for the production of electricity on small to medium size scaled power plants. The problem of high specific investment costs for machinery such as steam boilers are overcome due to the low working pressures in ORC power plants. The ORC process also helps to overcome the relatively small amount of input fuel available in many regions because an efficient ORC power plant is possible for smaller sized plants.[3]Biomass, a renewable energy source, is biological material from living, or recently living organisms,[1] such as wood, waste, (hydrogen) gas, and alcohol fuels. Biomass is commonly plant matter grown to generate electricity or produce heat. In this sense, living biomass can also be included, as plants can also generate electricity while still alive.[2] The most conventional way on how biomass is used however, still relies on direct incineration. Forest residues for example (such as dead trees, branches and tree stumps), yard clippings, wood chips and garbage are often used for this. However, biomass also includes plant or animal matter used for production of fibers or chemicals. Biomass may also include biodegradable wastes that can be burnt as fuel. It excludes organic materials such as fossil fuels which have been transformed by geological processes into substances such as coal or petroleum.

 

Industrial biomass can be grown from numerous types of plants, including miscanthus, switchgrass, hemp, corn, poplar, willow, sorghum, sugarcane[3], and a variety of tree species, ranging from eucalyptus to oil palm (palm oil). The particular plant used is usually not important to the end products, but it does affect the processing of the raw material.

 

Although fossil fuels have their origin in ancient biomass, they are not considered biomass by the generally accepted definition because they contain carbon that has been "out" of the carbon cycle for a very long time. Their combustion therefore disturbs the carbon dioxide content in the atmosphere.

 

Plastics from biomass, like some recently developed to dissolve in seawater, are made the same way as petroleum-based plastics. These plastics are actually cheaper to manufacture and meet or exceed most performance standards, but they lack the same water resistance or longevity as conventional plastics.[4]

 

Contents

 

* 1 Chemical composition

 

* 2 Biomass sources

 

* 3 Biomass conversion process to useful energy

 

o 3.1 Thermal conversion

 

o 3.2 Chemical conversion

 

+ 3.2.1 Biochemical conversion

 

* 4 Environmental impact

 

* 5 See also

 

* 6 References

 

* 7 External links

 

* 8 Further reading

 

 

 

Chemical composition

 

 

Biomass is carbon based and is composed of a mixture of organic molecules containing hydrogen, usually including atoms of oxygen, often nitrogen and also small quantities of other atoms, including alkali, alkaline earth and heavy metals. These metals are often found in functional molecules such as the porphyrins which include chlorophyll which contains magnesium.

 

Biomass sources

 

Biomass energy is derived from five distinct energy sources: garbage, wood, waste, landfill gases, and alcohol fuels. Wood energy is derived both from direct use of harvested wood as a fuel and from wood waste streams. The largest source of energy from wood is pulping liquor or “black liquor,” a waste product from processes of the pulp, paper and paperboard industry. Waste energy is the second-largest source of biomass energy. The main contributors of waste energy are municipal solid waste (MSW), manufacturing waste, and landfill gas. Biomass alcohol fuel, or ethanol, is derived almost exclusively from corn. Its principal use is as an oxygenate in gasoline.[5]

 

 

 

Biomass can be converted to other usable forms of energy like methane gas or transportation fuels like ethanol and biodiesel. Methane gas is the main ingredient of natural gas. Smelly stuff, like rotting garbage, and agricultural and human waste, release methane gas - also called "landfill gas" or "biogas." Crops like corn and sugar cane can be fermented to produce the transportation fuel, ethanol. Biodiesel, another transportation fuel, can be produced from left-over food products like vegetable oils and animal fats.[6] Also, Biomass to liquids (BTLs) and cellulosic ethanol are still under research.[7][8]

 

[biomass conversion process to useful energy

 

 

 

There are a number of technological options available to make use of a wide variety of biomass types as a renewable energy source. Conversion technologies may release the energy directly, in the form of heat or electricity, or may convert it to another form, such as liquid biofuel or combustible biogas. While for some classes of biomass resource there may be a number of usage options, for others there may be only one appropriate technology.

 

[edit] Thermal conversion

 

 

 

These are processes in which heat is the dominant mechanism to convert the biomass into another chemical form. The basic alternatives are separated principally by the extent to which the chemical reactions involved are allowed to proceed (mainly controlled by the availability of oxygen and conversion temperature):Combustion, Torrefaction, Pyrolysis, Gasification.

 

 

 

There are a number of other less common, more experimental or proprietary thermal processes that may offer benefits such as hydrothermal upgrading (HTU) and hydroprocessing. Some have been developed for use on high moisture content biomass, including aqueous slurries, and allow them to be converted into more convenient forms. Some of the Applications of thermal conversion are Combined heat and power (CHP) and Co-firing. In a typical biomass power plant, efficiencies range from 20-27%.[9]

 

Chemical conversion

 

A range of chemical processes may be used to convert biomass into other forms, such as to produce a fuel that is more conveniently used, transported or stored, or to exploit some property of the process itself.

 

Biochemical conversion

 

A microbial electrolysis cell can be used to directly make hydrogen gas from plant matter

 

As biomass is a natural material, many highly efficient biochemical processes have developed in nature to break down the molecules of which biomass is composed, and many of these biochemical conversion processes can be harnessed.

 

Biochemical conversion makes use of the enzymes of bacteria and other micro-organisms to break down biomass. In most cases micro-organisms are used to perform the conversion process: anaerobic digestion, fermentation and composting. Other chemical processes such as converting straight and waste vegetable oils into biodiesel is transesterification.[10] Another way of breaking down biomass is by breaking down the carbohydrates and simple sugars to make alcohol. However, this process has not been perfected yet. Scientists are still researching the effects of converting biomass.

 

Environmental impact

 

On combustion, the carbon from biomass is released into the atmosphere as carbon dioxide (CO2). The amount of carbon stored in dry wood is approximately 50% by weight.When from agricultural sources, plant matter used as a fuel can be replaced by planting for new growth. When the biomass is from forests, the time to recapture the carbon stored is generally longer, and the carbon storage capacity of the forest may be reduced overall if destructive forestry techniques are employed.

 

The existing biomass power generating industry in the United States, which consists of approximately 11,000 MW of summer operating capacity actively supplying power to the grid, produces about 1.4 percent of the U.S. electricity supply.[12]

 

Currently, the New Hope Power Partnership is the largest biomass power plant in North America. The 140 MW facility uses sugar cane fiber (bagasse) and recycled urban wood as fuel to generate enough power for its large milling and refining operations as well as to supply renewable electricity for nearly 60,000 homes. The facility reduces dependence on oil by more than one million barrels per year, and by recycling sugar cane and wood waste, preserves landfill space in urban communities in Florida.

 

Biomass power plant size is often driven by biomass availability in close proximity as transport costs of the (bulky) fuel play a key factor in the plant's economics. It has to be noted, however, that rail and especially shipping on waterways can reduce transport costs significantly, which has led to a global biomass market. To make small plants of 1 MWel economically profitable those power plants have need to be equipped with technology that is able to convert biomass to useful electricity with high efficiency such as ORC technology, a cycle similar to the water steam power process just with an organic working medium. Such small power plants can be found in Europe.

 

 

 

Despite harvesting, biomass crops may sequester carbon. So for example soil organic carbon has been observed to be greater in switchgrass stands than in cultivated cropland soil, especially at depths below 12 inches.[20] The grass sequesters the carbon in its increased root biomass. Typically, perennial crops sequester much more carbon than annual crops due to much greater non-harvested living biomass, both living and dead, built up over years, and much less soil disruption in cultivation.

 

 

The biomass-is-carbon-neutral proposal put forward in the early 1990s has been superseded by more recent science that recognizes that mature, intact forests sequester carbon more effectively than cut-over areas. When a tree’s carbon is released into the atmosphere in a single pulse, it contributes to climate change much more than woodland timber rotting slowly over decades. Current studies indicate that recapturing carbon released by burning will take minimally hundreds of years.

 

 

Using biomass as a fuel produces the same air-pollution challenges as other fuels. Black carbon - a pollutant created by incomplete combustion of fossil fuels, biofuels, and biomass - is possibly the second largest contributor to global warming.[22] In 2009 a Swedish study of the giant brown haze that periodically covers large areas in South Asia determined that it had been principally produced by biomass burning, and to a lesser extent by fossil-fuel burning.[23] Researchers measured a significant concentration of 14C, which is associated with recent plant life rather than with fossil fuels.

* Geothermal plants

* Solar thermal power

 

Choice of the working fluid

 

 

The selection of the working fluid is of key importance in low temperature Rankine Cycles. Because of the low temperature, heat transfer inefficiencies are highly prejudicial. These inefficiencies depend very strongly on the thermodynamic characteristics of the fluid and on the operating conditions.

 

In order to recover low-grade heat, the fluid generally has a lower boiling temperature than water. Refrigerants and hydrocarbons are the two commonly used components.

 

Optimal characteristics of the working fluid :

 

* Isentropic saturation vapor curve :

 

Since the purpose of the ORC focuses on the recovery of low grade heat power, a superheated approach like the traditional Rankine cycle is not appropriate. Therefore, a small superheating at the exhaust of the evaporator will always be preferred, which disadvantages "wet" fluids (that are in two-phase state at the end of the expansion). In the case of dry fluids, a regenerator should be used.

 

* Low freezing point, high stability temperature :

 

Unlike water, organic fluids usually suffer chemical deteriorations and decomposition at high temperatures. The maximum hot source temperature is thus limited by the chemical stability of the working fluid. The freezing point should be lower than the lowest temperature in the cycle.

 

* High heat of vaporisation and density :

 

 

A fluid with a high latent heat and density will absorb more energy from the source in the evaporator and thus reduce the required flow rate, the size of the facility, and the pump consumption.

 

 

 

* Low environmental impact

 

 

 

The main parameters taken into account are the Ozone depletion potential (ODP) and the global warming potential (GWP).

* Safety

The fluid should be non-corrosive, non-flammable, and non-toxic. The ASHRAE safety classification of refrigerants can be used as an indicator of the fluid dangerousness level.

* Good availability and low cost

 

* Acceptable pressures

B)

See also

 

* Rankine cycle

 

* Thermodynamic cycle

 

* Relative cost of electricity generated by different sources

 

 

 

Thermodynamic cycles

 

Cycles normally with

 

external combustion

 

Gas cycles without phasechange -

 

hot air engine cycles

 

 

Bell Coleman cycle · Brayton/Joule cycle; (Externally heated) · Carnot cycle · Ericsson cycle · Ported constant volume cycle[1] · Stirling cycle · Pseudo Stirling cycle (same as Adiabatic Stirling cycle) · Stoddard cycle · Vuilleumier cycle

 

Cycles with phasechange

 

Kalina cycle · Rankine cycle (encompasses Organic Rankine Cycle) · Regenerative cycle · Two phased Stirling cycle[2]

 

Cycles normally with internal combustion

 

Atkinson cycle · Brayton/Joule cycle · Diesel cycle · :rolleyes: Homogeneous Charge Compression Ignition · Lenoir cycle · Miller cycle · Otto cycle B)

 

Cycle mixing

 

Combined cycle · HEHC cycle · Mixed/Dual Cycle

 

Not categorized

 

Claude cycle [3] · Claude dual-pressure cycle · Fickett-Jacobs cycle · Gifford-McMahon cycle [4] · Hirn cycle · Humphrey cycle · Siemens cycle · Hampson-Linde cycle · Linde dual-pressure cycle · Heylandt cycle · Kleemenko cycle

 

[edit] References

 

 

 

1. ^ Technological and Economical Survey of Organic Rankine Cycle Systems

 

2. ^ Experimental study and modeling of a low temperature Rankine Cycle for small scale cogeneration

 

3. ^ *ORC power animation

 

4. ^ Design and optimization of parabolic trough organic Rankine Cycle powerplants

 

5. ^ Solar micro-generator

 

6. ^ Micro combined heat and power operating on renewable energy for residential building

 

 

 

Consequently the allowed main transfert of energy from combustion chamber to engines is only "full-enthalpic" ( due only to the evaporation of the secondary fluid moving the main turbine with better efficiency). Also pressures in primary fluid (generally a silicone fluid) are reduced to less than 10 bars. Consequently in Rankine Cycle ORC power plants are drastically reduced the costs and the risks related to the common use of big dangerous high-pressure stainless steel heavy walled boilers: 10 bars higher limit is the common requirement in domestic heating circuits such sun-panels et cetera. There is a godd chance to improve efficiency in old steam plants by retrofitting an heat eschanger to the primary and regaining commonly wasted heat. Pls visit such site

post-491-075748000 1284886755_thumb.png

post-491-029299900 1284886799_thumb.png

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...