Heat to Electricity - ORC Trubines

ORC Turbines can produce electricity by recovering heat from industrial processes, reciprocating engines and gas turbines. The main advantages of this cycle are due to the fluid, which allows heat recovery from lower temperature sources than water, such as industrial waste heat, solar ponds ... and the fact that both fluids are in separate circuits, which enable a better control. In addition, the working fluid is composed of organic vapor at low pressure, which helps to lubricate the turbine and reduce the risk of leaks and corrosion.

Principle

The general principle is the same than for steam turbines, the difference lies in the two fluid circuits.The turbogenerator uses the hot temperature thermal oil to pre-heat and vaporize a suitable organic working fluid in the evaporator (isobar transformation: 2 3 4). The organic fluid vapor powers the turbine, which is directly coupled to the electric generator through an elastic coupling. The exhaust vapor flows through the regenerator (5 9) where it heats the organic liquid (2 8). The vapor is then condensed in the condenser (cooled by the water flow) (9 6). The organic fluid liquid is finally pumped (6 2) to the regenerator and then to the evaporator, thus completing the sequence of operations in the closed-loop circuit.

As the boiling point of the high molecular mass fluid used is occurring at a lower temperature than water, the fluid allows heat recovery from lower temperature sources.

Energy sources


Example of applications

Biomass

Cogeneration plants with ORC turbines can produce heat and electrical power from wood biomass with high efficiency. The generated power usually ranges between 200 kW and 2.5 MW electric.
Biomass is available all over the world. 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.

Heat recovery

ORC turbines can produce electricity by recovering heat from industrial processes and combined cycles. Waste heat recovery is one of the most important development fields for ORC Turbines. It can be applied to heat and power 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.

Geothermal

ORC turbines can produce electricity from geothermal fluids typically in the range 90 to 200°C. The ORC is therefore perfectly adapted for this kind of application.

Solar

Those turbines allow to convert the heat collected by solar collectors into electricity through an efficient thermodynamic cycle. The ORC allows a lower collector temperature, a better collecting efficiency (reduced ambient losses) and hence the possibility of reducing the size of the solar

Copyright © 2010 Voltas Technologies (Pty) LTD
Web Design by ThinkTank