Mass transfer performance of water recovery from flue gas of lignite boiler by composite membrane

2017 ◽  
Vol 115 ◽  
pp. 377-386 ◽  
Author(s):  
Fuxiang Zhang ◽  
Zhihua Ge ◽  
Yinli Shen ◽  
Xiaoze Du ◽  
Lijun Yang
Keyword(s):  
Mass Transfer ◽  
Composite Membrane ◽  
Flue Gas ◽  
Transfer Performance ◽  
Water Recovery

scholarly journals Preparation and Properties of Coal Ash Ceramic Membranes for Water and Heat Recovery from Flue Gas

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Haiping Chen ◽  
Xiangsheng Li ◽  
Jiadi Wei ◽  
Yijun Feng ◽  
Dan Gao
Keyword(s):  
Heat Transfer ◽  
Flue Gas ◽  
Heat Recovery ◽  
Ceramic Membrane ◽  
Sintering Temperature ◽  
Coal Ash ◽  
Ceramic Membranes ◽  
Transfer Performance ◽  
Water Recovery ◽  
Recovery Performance

In this paper, the manufacturing process of microceramic membrane is summarized. The main material of this membrane is fly ash which can reduce the sintering temperature and save the costs. The coal ash ceramic membrane (CACM) was characterized by XRD, SEM, and mercury intrusion method. The results show that the mullite phase formed by CACM at the sintering temperature of 1250°C has morphology and structural characteristics similar to the commercial microceramic membrane. The membrane surface is uniform and dense, without cracks; the pore diameter is 1–4 μm, and the porosity is 26.6%. Furthermore, the CACM and CMCM were compared at the aspects of water and heat recovery performance using flue gas. The experiment indicated that when the flue gas temperature was 50–85°C, the water recovery performance of these two kinds of membrane was similar. Also, the heat transfer capability of the coal ash ceramic membrane was close to that of the commercial microceramic membrane when the temperature range of flue gas was controlled between 50°C and 70°C. When the temperature of flue gas reaches 80°C, the heat transfer performance of the commercial ceramic membrane is better, and the difference of heat recovery between these two kinds of membranes is 19.3%. In general, the CACM and CMCM have similar mass transfer performance, and the heat transfer efficiency of CACM is lower than that of CMCM, but the costs of CACM is much lower than that of CMCM which has a good research prospect in the future.

Numerical Modeling and Simulation of Condensation Heat Transfer in a Bundle of Transport Membrane Tubes for Waste Heat and Water Recovery

2011 ◽  
Author(s):  
Cheng-Xian Charlie Lin ◽  
Dexin Wang ◽  
Ainan Bao
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Flue Gas ◽  
Transport Model ◽  
Waste Heat ◽  
Numerical Study ◽  
Tube Bundle ◽  
Inlet Temperature ◽  
Water Recovery ◽  
Species Transport

In this paper, a numerical study has been carried out to investigate the heat and mass transfer with condensation in a transport membrane tube bundle, which is used for recovering both heat and water from combustion flue gas. The tube wall is made of a specially designed porous material that is able to extract condensate liquid from the flue gas. The flue gas investigated consists of one condensable water vapor (H2O) and three noncondensable gases (CO2, O2, and N2). A simplified multi-species transport model was developed for the heat and mass transfer of flue gas. The condensation-evaporation process was simulated as a two-step chemical reaction. The RNG two-equation turbulence model was used for the turbulent flow. The numerical study was conducted within ranges of Reynolds number of 1.0×103–7×104 based on hydraulic diameter of flue gas channel, and 6.4×100–3.3×102 based on inner diameter of the water tube. Flue gas inlet temperature is within the range of 333.2–360.9 K, while the water inlet temperature is within the range of 293.9–316.7 K. Numerical results were compared with experimental data obtained in a parallel effort. It has been found that the developed multi-species transport model was able to predict the flue gas heat and mass transfer in the tube bundle with fairly good accuracy. The heat and mass depletion levels decrease with the increase of the flue gas Reynolds numbers. A new Nusselt number correlation was developed for flue gas convection in the tube bundle. Detailed results about temperature, mass fraction, enthalpy, and skin fraction factors are also presented and discussed.

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

2019 ◽  
Vol 43 (5) ◽  
pp. 1747-1759 ◽  
Author(s):  
Dan Gao ◽  
Zhaohao Li ◽  
Heng Zhang ◽  
Haiping Chen ◽  
Lin Wang ◽  
...  
Keyword(s):  
Composite Membrane ◽  
Flue Gas ◽  
Ceramic Composite ◽  
Water Recovery

Employing Inverted Brayton Cycle to Solve Stack Temperature Problems After Water Recovery From HAT Cycle Exhaust Gas

2008 ◽  
Author(s):  
Kuifang Wan ◽  
Yunhan Xiao ◽  
Shijie Zhang
Keyword(s):  
Flue Gas ◽  
Ambient Pressure ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Brayton Cycle ◽  
Exhaust Gas ◽  
Water Recovery ◽  
Electrical Efficiency ◽  
Exhaust Heat ◽  
Induced Draft Fan

By adding an induced draft fan or exhaust compressor between flue gas condenser and stack to make the turbine expand to a pressure much lower than ambient pressure, this paper actually employed inverted Brayton cycle to solve stack temperature problems after water recovery from Humid Air Turbine (HAT) cycle exhaust gas and compare the effect of different discharging methods on the system’s performance. Comparing with the methods of gas discharged directly or recuperated, this scenario can obtain the highest electrical efficiency under certain pressure ratio and turbine inlet temperature. Due to the introduction of induced draft fan, in spite of one intercooler, there are twice intercoolings during the whole compression since the flue gas condenser is equivalent to an intercooler but without additional pressure loss. So the compression work decreases. In addition, the working pressure of humidifier and its outlet water temperature are lowered for certain total pressure ratio to recover more exhaust heat. These enhance the electrical efficiency altogether. Calculation results show that the electrical efficiency is about 49% when the pressure ratio of the induced draft fan is 1.3∼1.5 and 1.5 percentage points higher than that of HAT with exhaust gas recuperated. The specific works among different discharging methods are very closely. However, water recovery is some extent difficult for HAT employing inverted Brayton cycle.

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