Proton exchange membrane fuel cell (PEMFC) stack temperature and cathode stoichiometric oxygen are very important control parameters. The performance and lifespan of PEMFC stack are greatly dependent on the parameters...Proton exchange membrane fuel cell (PEMFC) stack temperature and cathode stoichiometric oxygen are very important control parameters. The performance and lifespan of PEMFC stack are greatly dependent on the parameters. So, in order to improve the performance index, tight control of two parameters within a given range and reducing their fluctuation are indispensable. However, control-oriented models and control strategies are very weak junctures in the PEMFC development. A predictive control algorithm was presented based on their model established by input-output data and operating experiences. It adjusts the operating temperature to 80 ℃. At the same time, the optimized region of stoichiometric oxygen is kept between 1.8?2.2. Furthermore, the control algorithm adjusts the variants quickly to the destination value and makes the fluctuation of the variants the least. According to the test results, compared with traditional fuzzy and PID controllers, the designed controller shows much better performance.展开更多
The operating temperature of a solid oxide fuel cell (SOFC) stack is a very important parameter to be controlled, which impacts the performance of the SOFC due to thermal cycling. In this paper, an adaptive fuzzy cont...The operating temperature of a solid oxide fuel cell (SOFC) stack is a very important parameter to be controlled, which impacts the performance of the SOFC due to thermal cycling. In this paper, an adaptive fuzzy control method based on an affine nonlinear temperature model is developed to control the temperature of the SOFC within a specified range. Fuzzy logic systems are used to approximate nonlinear functions in the SOFC system and an adaptive technique is employed to construct the controller. Compared with the traditional fuzzy and proportion-integral-derivative (PID) control, the simulation results show that the designed adaptive fuzzy control method performed much better. So it is feasible to build an adaptive fuzzy controller for temperature control of the SOFC.展开更多
Protected fruit cultivation in China has developed very quickly from the early 1990s, and now it is an important branch in fruit cultivation. A brief review including fruit species, developing history, growing area, o...Protected fruit cultivation in China has developed very quickly from the early 1990s, and now it is an important branch in fruit cultivation. A brief review including fruit species, developing history, growing area, output, and distribution in the whole country is made in the paper. Characteristics of the dominant kinds of greenhouse, environmental control methods, and standards of temperature, humidity, light and CO2 for different fruit species are presented. Information on varieties, growing benefits, special management practices and other aspects of the main fruit species used for protected cultivation are also presented.展开更多
The preparation of crystal form of Al（OH）3 from the deposited residues of anodizing lines in the process of producing aluminum was studied. Alkali is used to dissolve the residue, and then blow CO2 is bellowed in, f...The preparation of crystal form of Al（OH）3 from the deposited residues of anodizing lines in the process of producing aluminum was studied. Alkali is used to dissolve the residue, and then blow CO2 is bellowed in, finally a kind of useful crystal Al（OH）3 is accessed by hydrolysis. The yield of the crystal Al（OH）3 was affected by temperature, pH and flow rate of CO2. The experimental results showed that under constant stirring, the optimized conditions was to control the temperature of 75-85℃, pH 7.5-9.0, CO/flow rate 60-80 mL/min. Using this method, the purpose of recovering valuable resources of Al, cleaning up the environment, and recycling of the by-product of Na2CO3 was achieved. It was of good economic and social benefits.展开更多
In this paper, lab scale production carried out of calcium carbonate in 400 mL open cylindrical beaker reactor following fuzzy logic approach is reported. 10 grams of Calcium hydroxide is mixed in 250 mL deionized wat...In this paper, lab scale production carried out of calcium carbonate in 400 mL open cylindrical beaker reactor following fuzzy logic approach is reported. 10 grams of Calcium hydroxide is mixed in 250 mL deionized water. Continuous jet supply of carbon dioxide is maintained at controlled flow rate. Reaction histories are noted for different reaction temperatures. Continuous constant magnetic stirring is applied to maintain homogeneity. The data obtained is fuzzified by constructing universe of discourse of temperature, reaction time, and amounts of reactants with reaction conversion. Rule based model is tabulated and results show that fuzzy logic approach is promising to set on data to plan and scale up the process. It is also found that a jump can not be made at this time with few studies of fuzzy logic applications to physiochemical processes unless otherwise amassing and storing up plentiful deduced explorations.展开更多
Herein, we for the first time doped Nb^5+into the low-temperature(<100°C) SnO2sol-gel route to tailor the electrical property of SnO2 layers and the band alignment between SnO2 and the normally used mixed pero...Herein, we for the first time doped Nb^5+into the low-temperature(<100°C) SnO2sol-gel route to tailor the electrical property of SnO2 layers and the band alignment between SnO2 and the normally used mixed perovskites. The results revealed that proper Nb5+doping increased the conductivity of the SnO2 electron transport layer(ETL), and the conduction band(CB) level of the SnO2 ETL was shifted down to approach the CB level of perovskites, which facilitated the electron injection from perovskite to SnO2, accelerated the charge transport, and reduced the non-radiative recombination, leading to improved power conversion efficiency from18.06% to 19.38%. The Nb^5+doping process provided an efficient route for fabricating high-efficiency perovskite solar cells(PSCs) at a temperature lower than 100°C, and promoted the commercialization progress of PSCs.展开更多
基金Project (2003AA517020) supported by the National High-Tech Research and Development Program of China
文摘Proton exchange membrane fuel cell (PEMFC) stack temperature and cathode stoichiometric oxygen are very important control parameters. The performance and lifespan of PEMFC stack are greatly dependent on the parameters. So, in order to improve the performance index, tight control of two parameters within a given range and reducing their fluctuation are indispensable. However, control-oriented models and control strategies are very weak junctures in the PEMFC development. A predictive control algorithm was presented based on their model established by input-output data and operating experiences. It adjusts the operating temperature to 80 ℃. At the same time, the optimized region of stoichiometric oxygen is kept between 1.8?2.2. Furthermore, the control algorithm adjusts the variants quickly to the destination value and makes the fluctuation of the variants the least. According to the test results, compared with traditional fuzzy and PID controllers, the designed controller shows much better performance.
文摘The operating temperature of a solid oxide fuel cell (SOFC) stack is a very important parameter to be controlled, which impacts the performance of the SOFC due to thermal cycling. In this paper, an adaptive fuzzy control method based on an affine nonlinear temperature model is developed to control the temperature of the SOFC within a specified range. Fuzzy logic systems are used to approximate nonlinear functions in the SOFC system and an adaptive technique is employed to construct the controller. Compared with the traditional fuzzy and proportion-integral-derivative (PID) control, the simulation results show that the designed adaptive fuzzy control method performed much better. So it is feasible to build an adaptive fuzzy controller for temperature control of the SOFC.
文摘Protected fruit cultivation in China has developed very quickly from the early 1990s, and now it is an important branch in fruit cultivation. A brief review including fruit species, developing history, growing area, output, and distribution in the whole country is made in the paper. Characteristics of the dominant kinds of greenhouse, environmental control methods, and standards of temperature, humidity, light and CO2 for different fruit species are presented. Information on varieties, growing benefits, special management practices and other aspects of the main fruit species used for protected cultivation are also presented.
文摘The preparation of crystal form of Al（OH）3 from the deposited residues of anodizing lines in the process of producing aluminum was studied. Alkali is used to dissolve the residue, and then blow CO2 is bellowed in, finally a kind of useful crystal Al（OH）3 is accessed by hydrolysis. The yield of the crystal Al（OH）3 was affected by temperature, pH and flow rate of CO2. The experimental results showed that under constant stirring, the optimized conditions was to control the temperature of 75-85℃, pH 7.5-9.0, CO/flow rate 60-80 mL/min. Using this method, the purpose of recovering valuable resources of Al, cleaning up the environment, and recycling of the by-product of Na2CO3 was achieved. It was of good economic and social benefits.
文摘In this paper, lab scale production carried out of calcium carbonate in 400 mL open cylindrical beaker reactor following fuzzy logic approach is reported. 10 grams of Calcium hydroxide is mixed in 250 mL deionized water. Continuous jet supply of carbon dioxide is maintained at controlled flow rate. Reaction histories are noted for different reaction temperatures. Continuous constant magnetic stirring is applied to maintain homogeneity. The data obtained is fuzzified by constructing universe of discourse of temperature, reaction time, and amounts of reactants with reaction conversion. Rule based model is tabulated and results show that fuzzy logic approach is promising to set on data to plan and scale up the process. It is also found that a jump can not be made at this time with few studies of fuzzy logic applications to physiochemical processes unless otherwise amassing and storing up plentiful deduced explorations.
基金supported by the National Natural Science Foundation of China (51273104 and 91433205)
文摘Herein, we for the first time doped Nb^5+into the low-temperature(<100°C) SnO2sol-gel route to tailor the electrical property of SnO2 layers and the band alignment between SnO2 and the normally used mixed perovskites. The results revealed that proper Nb5+doping increased the conductivity of the SnO2 electron transport layer(ETL), and the conduction band(CB) level of the SnO2 ETL was shifted down to approach the CB level of perovskites, which facilitated the electron injection from perovskite to SnO2, accelerated the charge transport, and reduced the non-radiative recombination, leading to improved power conversion efficiency from18.06% to 19.38%. The Nb^5+doping process provided an efficient route for fabricating high-efficiency perovskite solar cells(PSCs) at a temperature lower than 100°C, and promoted the commercialization progress of PSCs.
