Waste heat recovery solution: ORC technology by ZUCCATO ENERGIA
Companies are increasingly moving towards a sustainable corporate vision aimed at reducing their environmental impact. ORC technology meets this need by recovering the thermal power available in the waste gas and adding value to it by producing electricity. This technology allows to cover a part or all the electricity self-consumption of the factory with consequent economic savings on energy consumption, which can be reinvested in the company’s core business.
Organic Rankine Cycle working principle
The Organic Rankine Cycle has characteristics that make it ideal for heat recovery and the exploitation of low-temperature heat sources in general. Its working principle is simple: (Fig.1):
Fig.1 ORC technology
Technological and Operational Advantages
Zero Emissions. ORC systems are impeccably eco-friendly. The entire process has zero emissions in the atmosphere, it uses an HFC working fluid and a thermal transfer fluid both completely “ozone-friendly”, non-toxic, fully eco-compatible. In particular, Zuccato Energia uses plain tape water for thermal energy transfer instead of environmentally - dangerous diathermal oil.
Less maintenance and zero supervision. The low operational pressures of ORC technology give great operational safety. Full-scale automatization removes the need to employ specialized personnel for operation and an integrated remote-control system grants the client full remote monitoring and management capabilities.
Long duration (up to 20 years and over). ORC system has different elements that allow a long duration as the completely dry working fluid, CNC machined steel body with aluminium alloy impeller and use of ceramic bearings.
Custom designed components. Implementation of single-stage turbines specifically designed in-house for each ORC model and custom-designed power converters (inverters) for each model guarantees maximum efficiency in energy conversion (up to 90%); the direct coupling of the generator to the turbine shaft eliminates the need for a gearbox and eliminates the inherent efficiency losses.
Heat recovery from industry furnaces
One of the completed projects is at Borgonovo Glassworking – Italy. The factory, which covers 52,000 m2, produces about 45,000 tons of glass per year using two modern melting furnaces.
The recovery is carried out employing a heat exchanger which intercepts the fumes from the furnaces and uses them to heat some water, the vector fluid necessary for the operation of the ORC system. The fumes are cooled from a temperature of about 450 ° C up to 200 ° C while on the secondary side of the heat exchanger, pressurized water circulates at 10 bar at 140 ° C, which thanks to the heat of the fumes is heated up to 160 ° C. The system realized involves the operation of a ORC module that produces up to 200 kW of electricity. The plant is also characterized by an adiabatic cooler for the dissipation of the low-temperature heat generated by the ORC system during the production of electricity. (Fig. 2)