ORC ADVANTAGES OVER STEAM 

01. AVAILABILITY & RELIABILITY

With a track record of 98% average operating time, Turboden units offer unparallel levels of availability and electricity generation per installed capacity (MWh/MW).  

Maintenance requirements are extremely low both in terms of time and in costs. Planned maintenance once a year two man-days allowing for maintenance is normally scheduled during other equipment maintenacne continuous plant availability; a broad range of maintenance packages offered by Turboden can further support reaching peak power plant reliability and availability and bring operating risk down to a minimum. 

Turboden units are specifically designed for long duration, with over-sized components and safe design margins. Very long operational life due to the characteristics of the working fluid, that unlike steam is non eroding and non corroding for valve seats tubing and turbine blades Due to the use of a high molecular mass organic fluid instead of water, the ORC system offers superior performance and several mechanical advantages:

• Low turbine mechanical stress due to low peripheral speed
• Low turbine RPM, allowing the direct drive of the electric generator without gear reduction
• No erosion of blades thanks to the absence of moisture in the vapor nozzles

02. SIMPLICITY & EASE OF OPERATION

In order to superheat the steam, steam boilers operate at temperature higher than 450°C and pressure of about 60-70 bars. In addition to the operational complexity of dealing with such thermal stress, steam plants require licensed operators and increased safety standards. 

Thermal oil boilers operate at lower temperature and pressure. ORC plants are designed for automatic and continuous operation and can be operated even by unskilled personnel with weekly operation requirements as low as 3-5 hours.

Furthermore contrary to the complex and lengthy start stop procedures required for steam turbines,   Turboden ORC follow a simple with the push of a button in 20-30 minutes time.  a short and simple start 

03. LOW MAINTENANCE | LONG OPERATIONAL LIFE

Maintenance requirements for ORCs are extremely low both in terms of time and in costs. Unlike steam the working fluid is non-eroding and non-corroding for valve seats tubing and turbine blades allowing for long operational life. Planned maintenance typically occurs once a year for two man-days allowing for continuous plant availability and low costs. 

The maintenance of steam systems is complicated and costly, involving steam traps, valves, condensate return pumps, and several different systems for controlling steam and water quality. Steam turbines typically require major overhauls at 5 year intervals.

04. ENVIRONMENTALLY FRIENDLY

Thermal oil based systems are closed loop systems with zero liquid waste.  

In contract, steam based systems have considerable environmental issues with the disposal of steam blowdown and condensate streams since in order to reduce corrosion the water in a steam system undergoes chemically treatment.  

05. EXCELLENT PARTIAL LOAD BEHAVIOR 

Turboden ORC units demonstrate an excellent behavior in variable flow and temperature conditions maintaining 90% of the cycle efficiency at 50% load and can operate even at 10% of the nominal load. 

On the contrary steam turbines have limited turn-down capabilities with a steep dro0p in efficiency when operating at low loads.