Organic Rankine Cycle technology is known for its flexibility of use for different applications and heat source temperatures, and for its adaptability to various environments and processes. This flexibility is possible thanks to the customization of the ORC design cycle, the choice of the best working fluid to better exploit the heat sources, and various other technical choices.
Nevertheless there are situations in which a plug-and-play standard product is the solution sought by the customer or is advantageous for a specific need.
Exergy has made “product customization” one of its strengths, delivering highly efficient and flexible power plants responding to the customer’s needs. To complete its array of products and offer its customers the possibility of choosing the best trade-off in terms of competitiveness and efficiency, Exergy’s R&D department has recently developed the new pre-engineered Exergy ORC-lite series of modules.
The Exergy ORC-lite standard system effectively responds to the market needs for small and compact ORC units with a faster time to market and lower costs to produce power on-site from various heat sources at low and high temperatures. The new Exergy ORC-lite series includes modules of 1.1 MWe, 1.4 MWe, 2.4 MWe and 5 MWe power sizes.
Exergy ORC-lite modules: features
The Exergy ORC-lite module is a compact unit where the main system equipment, including the ORC turbine, generator, lube/seal oil system, and feed pump is delivered already pre-assembled and tested on a compact skid-module (around 12 m length x 2.2 m width).
Heat exchangers, safety valves, interconnecting piping and minor components in between are supplied loose and fully prefabricated for easy on-site assembly.
The working fluid selected for the low temperature ORC standard modules is a refrigerant type giving the advantages of excellent thermal stability, low global warming potential, no flammability, and availability on the market. For high temperature applications the selected fluid is a hydrocarbon, the best fluid to extract the maximum power from the warmer resources.
Standard Vs. customized ORCs solutions
What are the main drivers for choosing a standard or a customized ORC system?
A customized ORC system is generally the best choice when the driver is to exploit the full potential of the heat energy source available. But there are some cases in which both solutions can be good options and the choice is then driven by the different benefits that the two solutions can give. In the table below both solutions are compared:
| Exergy ORC-lite module | Customized ORC system | |
| Power Output | Up to 5 MWe | Any power output |
| Flexibility | High flexibility of installation, low flexibility for power plant design | High flexibility of power plant design, lower flexibility for installation |
| Compactness | More compact | Depending on the design and size |
| Time to market | Relatively fast | Depending on the customization and power size but anyway longer than the standard module |
| Installation | Easier and faster | Longer than standard module |
| Costs of production and installation | Lower than customised product | Higher than standard module |
| Power plant efficiency | Good efficiency | Optimised efficiency |
ORC standard module: in which cases is it the best option?
Summarising, an ORC standard module could be the perfect match if you need:
- A small sized power size unit
- A compact solution due to site restrictions or environmental constraint
- A flexible solution allowing modular installation
- A faster deployment and start-up
- A cost-competitive driven choice
- A low temperature ORC solution using non-flammable working fluid
Applications
The ORC standard systems can fit the application with heat sources at temperatures between 90°C and 310°C in various applications, such as:
- Energy intensive industrial processes
- Geothermal
- Biomass
- Solar thermal CSP
- Power stations (diesel and gas engines)
Energy Intensive industrial processes
This application includes recovering waste heat available in cement manufacturing processes, glass manufacturing, steel manufacturing and chemical plants.
Geothermal
In the geothermal sector both standards and customized ORC power plants can be employed to produce electricity from geothermal resources. Find out more on about Exergy’s customized geothermal systems delivered worldwide
Biomass
ORC technology is the ideal choice for small biomass plants due to its high efficiency, availability and ability to follow loads dependent on fuel supply. Either a standard ORC module or a customized solution are possible according to the customer needs and technical requirements.
Solar Thermal CSP
The Organic Rankine Cycle (ORC) is suitable for CSP application, converting the thermal energy collected by solar panels into electricity through a thermodynamic cycle with a high level of efficiency.
Power Stations
Recovering exhaust heat from gas turbines and internal combustion engines is an easy way to optimise efficiency and performance while reducing the environmental impact of power generation plants widely employed for processing and refining in the Oil & Gas sector and at electricity production generating stations. Find out more in our case study.
Want to learn more about the new Exergy ORC-lite series ? Contact us
