ORC technology – transforming waste heat into clean electricity The ORC (Organic Rankine Cycle) is a cyclic, thermodynamic process. It uses an organic working fluid that enables the generation of electric power at comparatively low temperatures.
The cyclic process: simple principle, amazing effect
The physics of the Organic Rankine Cycle are fairly simple and comparable to experiments that you may have conducted at school. The working fluid is heated until it changes from a liquid to a gas. This is done by harvesting the thermal energy in waste heat in a heat exchanger, which is then used by the ORC process to gasify the working fluid. When the working fluid becomes a gas, this gas has more volume than the liquid and pressure starts to build. The outlet for this pressure is through a turbine. As the gas expands through the turbine, it make the turbine rotate which in turn makes the generator rotate.
When the gas exits the turbine it is still relatively hot. The physical properties of the working fluid used in ZE ORC equipment allows additional heat to be recovered from it. This residual heat is used to warm the liquid working fluid. This is known as recuperation. It helps the process be efficient. The working fluid then passes through a condenser. This is a heat exchanger that is used to cool the working fluid which turns back into a liquid. This liquid is then passed around the system again, completing the cycle.
The ZE Group ORC process is a closed loop with no fuel consumed. The cooling circuit is a closed loop. The heat rejected in this cooling circuit can be used for other processes, such as space heating, hot water or adsorption chilling.