Power Industry Webinar Production & Promotion

Flue gas heat utilization by fluoropolymer-tubed heat exchangers: the economic solution for FGD retrofits and efficiency increases at coal-fired power plants

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The utilization of residual heat energy from the exhaust gas downstream of the dust filter at fossil-fired power stations offers a variety of convincing customer benefits, such as

  • reduction of pollutant emissions,

  • reduction of water consumption during flue gas desulfurization,

  • prevention of corrosion in flue gas ducts and dry stacks,

  • avoidance of aerosol condensation and plume at stack outlet and

  • increase of the overall plant efficiency.

Due to these advantages and its relatively short return of investment periods, the technology of fluoropolymer-tubed heat exchangers for flue gas heat utilization is already installed in more than 150 reference plants ranging from 100 to 1000 MWel.

Below are some of the questions discussed during the webinar:

  • What is the typical pressure drop on the gas side of the heat exchanger (HE)? How do you handle a tube rupture in the HE?

  • How does the cost of fluoropolymer tube heat exchangers compare to rotary gas-gas heaters (GGH) for a 500 MW plant?

  • Given that rotary GGHs can experience fouling due to dirty and corrosive fluids, how does your compact GGH remain clean after several years of operation under these conditions?

  • Instead of using complete fluoropolymer tubes, can we use carbon steel tubes with a fluoropolymer coating? Would this provide benefits in terms of performance, lifetime, and cost?

  • Do we need a hot gas bypass to account for overtemperature risks during abnormal situations?

  • Will high dust loading affect the operation of fluoropolymer heat exchangers, for example in waste incineration?

  • What is the maximum flue gas temperature that fluoropolymer heat exchangers can sustain?

  • Can the material be used for feedwater heaters, where heat is transferred from flue gas to feedwater, reducing turbine extraction, while still using a wet stack?

  • How does the wear resistance of fluoropolymer compare to carbon steel?

  • What would be the difference in efficiency improvement between the following two cases: 1. Flue gas heat recovery to combustion air 2. Flue gas heat recovery to condensate/feedwater?

  • What are the operating conditions (temperature, pressure, strength) under which the fluoropolymer heat exchanger can operate to check its suitability for retrofitting in existing glass tube APHs (air preheaters) of oil and gas-fired furnaces (not coal-fired)?

  • What will be the approximate pressure drop on the shell side and tube side for a GGH type heat exchanger?

  • If we add this GGH to an existing unit, what will be the impact on our running ID fan?

  • What is the flue gas temperature at the GGH outlet?