Flash-steam heat recovery
Information
Flash steam released from hot condensate can be recovered and applied elsewhere in the plant to maximise overall efficiency. Recovery systems reduce steam-raising costs, utility bills and CO2 emissions, and help achieve significant savings in fuel, water and feed-water chemicals. The return on investment is quick (around 3.4 years with the assumptions taken here). Jacketed vessels, flash-steam recovery vessels, and several other tools are available to operate flash steam recovery.
Some conditions need to be satisfied for successful flash-steam application:
- Continuous supply of sufficient condensate from applications operating at higher pressures is needed, to ensure enough flash steam can be released for economic recovery
- Steam traps and the equipment they are draining must function satisfactorily against the back-pressure applied by the flash system
- The overall potential for flash-steam formation must be assessed to determine if recovery is worthwhile
- Demand for low-pressure flash steam must equal or exceed the flash steam being produced
- Flash steam can be used from condensate on a space-heating installation, but savings will only be achieved when space heating is in demand (e.g. colder months)
- Flash steam should ideally be used close to the high-pressure condensate source, to avoid the costs of piping flash steam over distances
Spiraxsarco, Flash recovery energy management equipment, http://www.spiraxsarco.com/global/pt/Products/Documents/Spirax_FREME_Fl…
Spiraxsarco, Flash steam, http://www.spiraxsarco.com/Resources/Pages/Steam-Engineering-Tutorials/…
EAUC-Scotland and Resource Efficient Scotland (RES), Energy Efficiency Technologies Catalogue, http://www.sustainabilityexchange.ac.uk/energy_efficiency_technologies_…