Renewable Energy Ventures

Renewable Energy Ventures is a developer of renewable energy projects providing engineering, legal, finance, feasibility studies and greenhouse gas emissions consulting for projects located in the U.S. and Canada.    

We also provide renewable energy engineering services for clients with projects located in Central America and the Caribbean.  

We specialize in the following renewable energy technologies: 

• Anaerobic Digesters

• Biodiesel Plants

• Biogas Plants

• Biogas to Biomethane

• Biomass Gasification

• Biomethane 

• Carbon Free Energy

• Cogeneration

• Community Wind Farms

• Concentrating Solar Power 

• Decentralized Energy

• Demand Side Management

• Distributed Generation

• Geothermal Power Plants 

• Ground Source Heat Pumps

• Hydrogen Fuel Cells

• Molten Carbonate Fuel Cells

• Onsite Power Generation

• "Natural Wastewater Treatment Plants" 

• Phosphoric Acid Fuel Cells

• Plasma Gasification 

• Pollution Free Power

• Solar Cogeneration

• Solar Trigeneration

• Thin Film Photovoltaics

• Trigeneration

• Waste To Energy 

• Waste to Fuel 

• Wind Farm Development

• Wind Power Generation

For more information, call (18324)7 758 - 00277

or send an email to:  info@RenewableEnergyVentures.com

Organic Rankine Cycle
www.OrganicRankineCycle.com

Engineering, Products & Consulting Services

What is An Organic Rankine Cycle? 

A Rankine cycle is a closed circuit steam cycle. (Also - see Rankine Cycle). An "organic" Rankine cycle uses a heated chemical instead of steam as found in the Rankine Cycle. Chemicals used in the Organic Rankine Cycle include freon, butane, propane, ammonia, and the new environmentally-friendly" refrigerants. 

Why use a chemical refrigerant? 

A refrigerant boils at a temperature below the temperature of frozen ice. Solar heat, for example, of only 150 degrees Fahrenheit from a typical rooftop solar hot water heater, will furiously boil a refrigerant. The resulting high-pressure refrigerant vapor is then piped to an organic Rankine cycle engine. 

Why is it called "organic"? 

"Organic" is a term used in chemistry to describe a class of chemicals that includes Freon and most of the other common refrigerants. 

History of the Carnot Cycle, Rankine Cycle and Brayton Cycle

What is the Carnot Cycle?

The Carnot Cycle has been described as being the most efficient thermal cycle possible, wherein there is no heat losses, and consisting of four reversible processes, two isothermal and two adiabatic. It has also been described as a cycle of expansion and compression of a reversible heat engine that does works with no loss of heat.

What is the Rankine Cycle?

The Rankine cycle is a thermodynamic cycle used to generate electricity in many power stations, and is the real-world approach to the Carnot cycle. Superheated steam is generated in a boiler, and then expanded in a steam turbine. The steam turbine drives a generator, to convert the work into electricity. The remaining steam is then condensed and recycled as feed-water to the boiler. A disadvantage of using the water-steam mixture is that superheated steam has to be used, otherwise the moisture content after expansion might be too high, which would erode the turbine blades.

What is the Brayton Cycle?

A turbine operates on the principal of the Brayton Cycle, which is defined as a constant pressure cycle, with four basic operations which it accomplishes simultaneously and continuously for an uninterrupted flow of power.

Rudolph Diesel was educated at the predecessor school to the Technical University of Munich, Germany. In 1878, he was introduced to the work of Sadi Carnot, who theorized that an engine could achieve much higher efficiency than the steam engines of the day. Carnot envisioned a cycle in which a gas is compressed, heated, allowed to expand, and then cooled. After the gas is cooled, the cycle begins anew. Mechanical energy is used to compress the gas and thermal energy to heat it. In turn, expansion of the gas yields mechanical energy, and its cooling yields thermal energy. The net result is conversion of thermal energy to mechanical energy.¹

Diesel sought to apply Carnot’s theory to the internal combustion engine. The efficiency of the Carnot cycle increases with the compression ratio—the ratio of gas volume at full expansion to its volume at full compression. Nicklaus Otto invented an internal combustion engine in 1876 that was the predecessor to the modern gasoline engine. Otto’s engine mixed fuel and air before their introduction to the cylinder, and a flame or spark was used to ignite the fuel-air mixture at the appropriate time.² However, air gets hotter as it is compressed, and if the compression ratio is too high, the heat of compression will ignite the fuel prematurely. The low compression ratios needed to prevent premature ignition of the fuel-air mixture limited the efficiency of the Otto engine.

Rudolph Diesel wanted to build an engine with the highest possible compression ratio. He introduced fuel only when combustion was desired and allowed the fuel to ignite on its own in the hot compressed air. Diesel’s engine achieved an efficiency higher than that of the Otto engine and much higher than that of the steam engine. It also eliminated the trouble-prone electric-spark ignition system. Diesel received a patent in 1893 and demonstrated a workable engine in 1897.³ Today, diesel engines are classified as “compression-ignition” engines, and Otto engines are classified as “spark-ignition” engines.

www.OrganicRankineCycle.com

info@OrganicRankineCycle.com

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