About ORCs

Thermodynamic Cycle

The Organic Rankine Cycle's principle of operation is based on a turbogenerator working as a normal steam turbine to transform thermal energy into mechanical energy and finally into electric energy through an electric generator. Instead of the water to steam, the ORC system vaporizes an organic fluid, which has a molecular mass higher than water, which leads to a slower rotation of the turbine and lower pressure and erosion of the metallic parts and blades.

 

The ORC is based on the following thermodynamic cycle:

1. A heat source heats thermal oil to a high temperature, typically about 300°C, in a closed circuit;
2. The hot thermal oil is drawn to and from the ORC module in closed circuit. In the ORC it evaporatesthe organic working fluid of the ORC in a suitable heat exchanger system (pre-heater and evaporator) (8 3 4);
3. Organic vapour expands in the turbine, producing mechanical energy, further transformed into electric energy through a generator (4 5);
4. The vapour flows through a regenerato (5 9), where it heat the organic liquid (2 8).
5. The vapour is then cooled by a fluid (e.g. water) in a closed circuit and condensed (9 6 1). Typically, the water warms up to about 80 - 90°C and it can be used for different applications requiring heat;
6. The condensed organic fluid is pumped back into the regenerator and then to the evaporator, thus completing the closed loop circuit.

The ORC cycle has a high overall energy efficiency: 98% of incoming thermal power in the thermal oil is transformed into electric energy (around 20%) and heat (78%), with extremely limited thermal leaks, only 2 % due to thermal isolation, radiance and losses in the generator; the electric efficiency obtained in non cogenerative cases is much higher (around 24% and more).

Advantages of ORCs

Organic Rankine Cycle offers many advantages, such as:

• High turbine / thermodynamic cycle efficiency;
• Turbine low mechanical stress;
• Absence of moisture during the vapour expansion, responsible for the erosion of the blades;
• Simple start up procedures;
• Automatic and continuous operation;
• Simple maintenance procedure;
• No operator attendance required;
• Long life of the plant (> 20 years);
• No need to demineralize water.

Turboden ORC

Advantages of the Turboden ORC include:

• Experience: Turboden projects and manufactures ORC units since 1980
• References: Turboden has in operation more than 100 ORC units all over Europa (data May 2009)
• Performance: high performance at top level, due to in-house designed turbines and specifically selected fluids
• Reliability: 98% average functioning time
• Cutting-edge technology: Turboden has an internal R&D centre in Milan focusing on fluid dynamics research
• High-quality: due to careful production and testing at the internal production facility in Brescia
• Easy to use: the unit is designed to be easily operated even by unskilled staff
• Long operational life: our units are specifically designed for long duration, with over-sized components and safe design margins
• Customer satisfaction: we have clients buying different units over the years, the best proof of customer satisfaction. Moreover, we offer a high degree of unit customization following client specific needs
• After-sale services: extendable guarantees and maintenance packets

See www.turboden.eu for more information.

Applications

1. Biomass

Cogeneration plants with Turboden ORC can produce heat and electrical power from biomass with high efficiency and user friendly operation. The generated power usually ranges between 200 kW and 2.5 MW electric.

Suitable for:

• Local utilities feeding district heating
• Large sawmills
• Pellet manufacturing companies
• Manufacturers of MDF / OSB panels

2. Heat Recovery

Turboden ORCs can produce electricity by recovering heat from industrial processes, reciprocating engines and gas turbines. The power of Turboden units generally ranges between 400 kW and 5 MW electric.

Suitable for:

• Cement industry
• Glass industry
• Steel industry
• Non-ferrous furnaces
• Refineries
• Internal combustion engines and gas turbines

3. Solar Thermodynamic

Turboden units allow to convert the heat collected by solar collectors into electricity through an efficient thermodynamic cycle. Concentrating Solar Power systems with Turboden ORC can be cost-effective starting at 1MW.

Suitable for:

• Concentrating Collector Fields down to 4 ha
• Hybrid CSP plants, e.g. solar+biomass

4. Geothermal

Turboden/PureCycle® ORC units can produce electricity from geothermal resources with medium to low temperature, typically ranging between 90°C and 180°C.

Suitable for:

• Low and medium temperature geothermal systems
• Enhanced Geothermal Systems

See www.turboden.it for more information.

ORC Products

Combined Heat & Power Units with Split

To date most of Turboden's projects are in the field of cogeneration from wood biomass. Turboden turbogenerators electric power output generally ranges between 400 kW and 2 MW. The Turboden split system allows maximising electric power production for a given biomass consumption.

Turboden offers different standard models for CHP cogeneration:

• TURBODEN 6 CHP: around 600 kW net active electric power 
• TURBODEN 7 CHP: around 700 kW net active electric power 
• TURBODEN 10 CHP: around 1000 kW net active electric power 
• TURBODEN 14 CHP: around 1300 kW net active electric power 
• TURBODEN 18 CHP: around 1800 kW net active electric power 
• TURBODEN 22 CHP: around 2200 kW net active electric power

For more information and downloads, go to http://www.turboden.eu/en/products/products-chp.php

Heat Recovery Units

Turboden ORC technology is particularly suitable for producing electric energy by recovering heat from industrial processes and combined cycle systems. Turboden turbogenerators electric power output generally ranges between 400 kW and 5 MW.

Turboden offers different standard models for Heat Recovery, with the following typical performances in terms of net active electric production:

• TURBODEN 6 HR: around 600 kW
• TURBODEN 7 HR: around 700 kW 
• TURBODEN 10 HR: around 1000 kW 
• TURBODEN 14 HR: around 1300 kW 
• TURBODEN 18 HR: around 1800 kW 
• TURBODEN 22 HR: around 2200 kW

For more information and downloads, go to http://www.turboden.eu/en/products/products-hr.php

High Electrical Efficiency Units

Turboden has developed new models of turbogenerators (HRS) capable of ensuring high performance in terms of electrical efficiency in contexts with a strong presence of agricultural and forest biomass, but with discontinuous ability to allocate the heat.

HRS models can operate both in dissipative regime, maximizing the electrical output, and in cogeneration, with the opportunity to provide heat to any seasonal thermal load and making the most of the biomass.

Turboden offers two different HRS units:

• TURBODEN 12 HRS - split: up to 1112 kW net active electric power production 
• TURBODEN 24 HRS - split: up to 2224 kW net active electric power production

For more information and downloads, go to http://www.turboden.eu/en/products/products-hrs.php

Pure Cycle Units

Pratt & Whitney Power Systems Units for geothermal and low-temperature heat recovery applications Joining Pratt & Whitney Power System, Turboden becomes distributor for the European and African markets of PureCycle® power system, which is suitable for distributed generation projects with small size solutions for geothermal applications and for low-temperature heat recovery applications.

The PureCycle® power system is a closed-cycle process that uses any hot water resource to generate 280 kW (gross) of electrical power. The system is driven by a simple evaporation process and is entirely enclosed, which means it produces no emissions. The only byproduct is electricity, and the fuel – hot water – is a renewable resource. In fact, for geothermal applications, the water can be returned to the earth for re- heating, resulting in the ultimate recycling loop. Free fuel, coupled with low operating and maintenance costs, ensure this system will have an extremely attractive payback.

The PureCycle® power system can operate on a wide range of resource temperatures starting as low as 195°F (91°C). By operating at lower temperatures than conventional geothermal systems, the PureCycle® power system enables geothermal wells deemed unproductive because they are below 300°F (149°C) to become viable energy sources once again.

For more information and downloads, go to http://www.turboden.eu/en/products/products-purecycle.php