An experimental study on vapor condensation of wet flue gas in a plastic heat exchanger

Abstract

An experimental system investigating condensation heat transfer of wet flue gas was set up and the heat transfer performance of vapor-gas mixture with vapor condensation was discussed. The experimental results of laminar flow in a plastic longitudinal spiral plate heat exchanger were obtained and are in good agreement with the modified classical film model. It is shown that the plastic air preheater can avoid acid corrosion in the low-temperature field for the boiler using fuel containing sulfur and recover latent heat of the water vapor of the wet flue gas. Also some SO2 was scrubbed during the vapor condensing process in the heat exchanger.

Recent research developments in polymer heat exchangers – A review

“…Figure 6 Plastic heat exchanger cross-section 54 Because of the corrosive resistant feature, polymer heat exchangers are also applied for flue gas recovery in power generation process. An experimental study on the heat transfer performance of wet flue gas heat recovery system using a plastic longitudinal spiral plate heat exchanger was presented by Jia et al 56 . The plastic heat exchanger was used as air preheater which avoided acid corrosion in the low temperature field for boiler using fuel containing sulphur and recover latent heat of the water vapour from the wet flue gas.…”

The investigation of desulphurization and water recovery from flue gas using ceramic composite membrane

“…water relative molecular mass MN2 relative molecular mass of N 2 n amount of substance (mol) ncd amount of substance of condensate (mol/s) P pressure (Pa) P 0 saturated vapor pressure in the plane (Pa) P 1 saturated vapor pressure in the capillary (Pa) P tot flue gas pressure (kPa) q w water content in flue gas (L/(m 2 ·h)) R universal gas constant r pore size of the selective layer (m) r i membrane inner diameter (m) r o membrane outer diameter (m) T temperature (K) T c cooling water temperature (K) T c,in cooling water inlet temperature (K) T c,out cooling water outlet temperature (K) T g flue gas temperature (K) T g,in inlet temperature of flue gas (K) T g,out outlet temperature of flue gas (K) T i gas-liquid interface temperature (K) T sat water dew point temperature (K) U overall heat transfer coefficient of the membrane side (W/(m 2 ·K)) V volume (m 3 ) y H2O mole fraction of water vapor (%) y H2O,in mole fraction of water vapor at flue gas inlet (%) y H2O,out mole fraction of vapor at gas outlet (%) y i vapor mole fraction in gas-liquid interface (%) y lm nitrogen logarithmic mean mole fraction in non-condensable layer (%) y ni nitrogen mole fraction in gas-liquid interface (%) y nb mole fraction of nitrogen in the primary flow area (%)…”

“…Typical methods for capturing water vapor from humidified gas include condensation, drying, and composite membrane . Among them, the composite membrane method primarily uses gas membrane separation technology to realize the separation of water vapor from other gases.…”

Research on Boiler Flue Gas Heat Recovery with Fluoroplastic Heat Exchangers

“…In the mid-20th century, Thyssen of Germany, the leading company in the industries of steel and iron and machinery manufacturing, installed multilevel circulating coolers on the exhaust hoods of sintering coolers of the workshop for preheating air [1] ; Schwarze Pumpe of Germany removed gas from the flue between the electrostatic precipitator and the desulphurizing tower, and installed a flue gas cooling unit to recover waste heat for heating boiler condensate [2] . As the first country who generated power by waste heat in the world, Japan built a set of power generation system, by which flue gas is used as low-temperature heat source to generate vapor and power; under the direction of Alam and Boe-hman, driven by waste heat, the system had the capacity and efficiency of refrigeration improved [3] .…”