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Empowering Cleaner Energy Decisions
Energy efficiency measures - Industrial - Heating system - Makeup water - Preheating

Template assignment

Base Case
  • Natural gas fired boiler provides steam to a process
  • Boiler makeup water preheated using boiler blowdown and heated up to 110 ºC in the deaerator using steam, boiler seasonal efficiency is 81.4%
  • Combustion gas at 185 ºC is rejected to the atmosphere
  • Process steam flow required is 11,360 kg/h during 6,000 h/yr
  • Steam pressure is 960 kPa at saturated temperature of 178 ºC
  • Condensate temperature is 71 ºC, 56% return
  • Makeup water temperature is 10 ºC
  • Natural gas rate is $8.03/GJ

Proposed case
  • Install a condensing economizer on boiler stack to preheat boiler makeup water. This will reduce the steam usage in the deaerator; therefore, increasing the steam boiler seasonal efficiency from 81.4 to 87%
  • Cost of retrofit is $200,000

Base case

Base case
Proposed case

Proposed case
Solution

The worked-out solution is the data file selected from within the RETScreen Project Database. The user automatically downloads the Project Database file while downloading the RETScreen software.