The work carried out consists in recovering the heat contained in the fumes of a 5 t/h steam generator. The generator is newly installed (2015) and replaces a diathermic oil generator with a capacity of 3.5 t/h and obsolete evaporator.
In particular, it is proposed to recover the thermal energy contained in the exhaust fumes leaving the new steam generator and reuse this heat for:
- Preheat the boiler's feed water.
- Preheat the make-up water of the boiler itself.
This recovery can be obtained through a system divided into two stages of air/water heat exchange.
The first recovery stage (ECO): involves using the heat contained in the flue gases leaving the steam generator to preheat the feeding water.
The second recovery stage (RC2): this involves using the heat contained in the flue gases leaving the first stage to preheat the make-up water (demineralised).
The two recovery stages work in series and guarantee a considerable saving of natural gas.
Results obtained:
- Thermal energy saving: 923.000 kWh/year
- Primary energy saving: 89 Toe/year
- Saving of natural gas: 107.000 scm/year
- CO2 not released into the atmosphere: 209 tons/year
- Payback intervention: about 24 months
The system has been equipped with a monitoring system able to measure and historicize the post-intervention consumption. This is essential for taking stock of and verifying the energy savings achieved.
The intervention has been analysed, designed and implemented by RENOVIS.
