Plate Heat Exchangers Recycle Heat To District Heating Loop, Helping Increase Thermal Efficiency By 20%

CHALLENGE

Capture waste heat from boiler flue gas condensate and cool this stream prior to purification and discharge.

SOLUTION

Three Tranter SUPERCHANGER® Plate And Frame Heat Exchangers with 254 SMOTM stainless steel (1.4547) plates to withstand chlorides and fluorides in the flue gas condensate.

  • Heat in the condensate from the top stage of the scrubber is transferred to the district heating loop through a Tranter Model GXD-205 exchanger.
  • A Model GCD-016 uses district heating water as cooling media for the Stage 4 flue gas condensate.
  • A GLD-013 unit uses ground water to further cool the Stage 4 water and also to cool process water from scrubber Stage 3, the sulfur dioxide step.
  • This condensate heat recovery strategy has potential for any boiler flue gas stream 150°C (300°F) or above.

RESULTS

The scrubber condensate is cooled to a temperature 1–2 °C (1.8–3.6°F) above the incoming district heating water.

Tranter GCD-016 and GLD-013 Plate Heat Exchangers recycle heat from upper scrubber stages and cool process water for temperature-controlled outflow.
Download: Case History About Waste-to-Energy Economizing Duties