Wells turbine has inherent disadvantages in comparison with conventional turbines: relative low efficiency at high flow coefficient and poor starting characteristics. To solve these problems, the authors propose Wells...Wells turbine has inherent disadvantages in comparison with conventional turbines: relative low efficiency at high flow coefficient and poor starting characteristics. To solve these problems, the authors propose Wells turbine with booster turbine for wave energy conversion, in order to improve the performance in this study. This turbine consists of three parts: a large Wells turbine, a small impulse turbine with fixed guide vanes for oscillating airflow, and a generator. It was conjectured that, by coupling the two axial flow turbines together, pneumatic energy from oscillating airflow is captured by Wells turbine at low flow coefficient and that the impulse turbine gets the energy at high flow coefficient. As the first step of this study on the proposed turbine topology, the performance of turbines under steady flow conditions has been investigated experimentally by model testings. Furthermore, we estimate mean efficiency of the turbine by quasi-steady analysis.展开更多
A twin unidirectional impulse turbine has been proposed in order to enhance the performance of wave energy plant. This turbine system uses two unidirectional impulse turbines and their flow direction is different each...A twin unidirectional impulse turbine has been proposed in order to enhance the performance of wave energy plant. This turbine system uses two unidirectional impulse turbines and their flow direction is different each other. However, the effect of guide vane solidity on the turbine characteristics has not been clarified to date. The performances of a uni- directional impulse turbine under steady flow conditions were investigated experimentally by using a wind tunnel with large piston/cylinder in this study. Then, mean efficiency of the twin impulse turbine in bidirectional airflow has been estimated by a quasi-steady analysis using experimental results in order to investigate the effect of guide vane solidity on the performance.展开更多
Treating protein-rich wastewater using cost-effective and simple-structured single-stage reactors presents several challenges.In this study,we applied an anaerobic sequencing batch reactor(AnSBR)to treat protein-rich ...Treating protein-rich wastewater using cost-effective and simple-structured single-stage reactors presents several challenges.In this study,we applied an anaerobic sequencing batch reactor(AnSBR)to treat protein-rich wastewater from a slaughterhouse.We focused on identifying the key factors influencing the removal of chemical oxygen demand(COD)and the settling performance of the sludge.The AnSBR achieved a maximum total COD removal of 90%,a protein degradation efficiency exceeding 80%,and a COD to methane conversion efficiency of over 70%at organic loading rates of up to 6.2 g COD L^(-1)d^(-1).We found that the variations in both the organic loading rate within the reactor and the hydraulic retention time in the buffer tank had a significant effect on COD removal.The hydraulic retention time in the buffer tank and the reactor,which determined the ammonification efficiencies and the residual carbohydrate concentrations in the reactor liquid,affected the sludge settleability.Furthermore,the genus Clostridium sensu stricto 1,known as protein-and lipids-degraders,was predominant in the reactor.Statistical analysis showed a significant correlation between the core microbiome and ammonification efficiency,highlighting the importance of protein degradation as the governing process in the treatment.Our results will provide valuable insights to optimise the design and operation of AnSBR for efficient treatment of protein-rich wastewater.展开更多
文摘Wells turbine has inherent disadvantages in comparison with conventional turbines: relative low efficiency at high flow coefficient and poor starting characteristics. To solve these problems, the authors propose Wells turbine with booster turbine for wave energy conversion, in order to improve the performance in this study. This turbine consists of three parts: a large Wells turbine, a small impulse turbine with fixed guide vanes for oscillating airflow, and a generator. It was conjectured that, by coupling the two axial flow turbines together, pneumatic energy from oscillating airflow is captured by Wells turbine at low flow coefficient and that the impulse turbine gets the energy at high flow coefficient. As the first step of this study on the proposed turbine topology, the performance of turbines under steady flow conditions has been investigated experimentally by model testings. Furthermore, we estimate mean efficiency of the turbine by quasi-steady analysis.
文摘A twin unidirectional impulse turbine has been proposed in order to enhance the performance of wave energy plant. This turbine system uses two unidirectional impulse turbines and their flow direction is different each other. However, the effect of guide vane solidity on the turbine characteristics has not been clarified to date. The performances of a uni- directional impulse turbine under steady flow conditions were investigated experimentally by using a wind tunnel with large piston/cylinder in this study. Then, mean efficiency of the twin impulse turbine in bidirectional airflow has been estimated by a quasi-steady analysis using experimental results in order to investigate the effect of guide vane solidity on the performance.
基金supported by Biothane Veolia Water Technologies Techno Center,KWR Water Research Institute and Hydrobusiness B.V as part of the TKI Project Innovative Slaughterhouse Wastewater Treatment TechnologyThis research was co-financed with PPS-funding from the Top consortia for Knowledge&Innovation(TKI’s)of the Dutch Ministry of Economic Affairs and Climate PolicyThe authors would like to thank China Scholarship Council for the State Scholarship Fund(No.201708450043)granted to the first author.
文摘Treating protein-rich wastewater using cost-effective and simple-structured single-stage reactors presents several challenges.In this study,we applied an anaerobic sequencing batch reactor(AnSBR)to treat protein-rich wastewater from a slaughterhouse.We focused on identifying the key factors influencing the removal of chemical oxygen demand(COD)and the settling performance of the sludge.The AnSBR achieved a maximum total COD removal of 90%,a protein degradation efficiency exceeding 80%,and a COD to methane conversion efficiency of over 70%at organic loading rates of up to 6.2 g COD L^(-1)d^(-1).We found that the variations in both the organic loading rate within the reactor and the hydraulic retention time in the buffer tank had a significant effect on COD removal.The hydraulic retention time in the buffer tank and the reactor,which determined the ammonification efficiencies and the residual carbohydrate concentrations in the reactor liquid,affected the sludge settleability.Furthermore,the genus Clostridium sensu stricto 1,known as protein-and lipids-degraders,was predominant in the reactor.Statistical analysis showed a significant correlation between the core microbiome and ammonification efficiency,highlighting the importance of protein degradation as the governing process in the treatment.Our results will provide valuable insights to optimise the design and operation of AnSBR for efficient treatment of protein-rich wastewater.
