Diesel particulate matter(DPF) is usually employed to meet the stringent regulations on particulate matter(PM) emissions for diesel engine. To resolve the DPF regeneration problem, comprehensive information about the ...Diesel particulate matter(DPF) is usually employed to meet the stringent regulations on particulate matter(PM) emissions for diesel engine. To resolve the DPF regeneration problem, comprehensive information about the factors influencing PM oxidation behaviors must be understood. Large amounts of factors related to PM oxidation activity have been investigated, however, some relations are still ambiguous. This paper reviews the factors related to PM oxidation activity that the factors are divided into the engine-correlated and engine-uncorrelated factors. The methods with both advantages and disadvantages to test the oxidation behaviors are introduced. The microstructure and ingredient being fundamental factors affecting PM oxidation behaviors are as the principle line to correlate PM oxidation behaviors and engine-correlated factors. The relations of engine-correlated factors with oxidation behaviors are obtained though advanced technologies that are mutual complementation. The engine-uncorrelated factors are also reviewed that these factors are vital to oxidation activity changes. Multiple-factor analysis rather than single-factor analysis should be developed to make the oxidation behaviors of diesel PM more clear.展开更多
In an organic Rankine cycle(ORC)system,the working fluid pump plays an important role in the system performance.This paper focused on the operating characteristics of a multistage centrifugal pump at various speeds an...In an organic Rankine cycle(ORC)system,the working fluid pump plays an important role in the system performance.This paper focused on the operating characteristics of a multistage centrifugal pump at various speeds and condensation conditions.The experimental investigation was carried out to assess the influence of the performance of the pump by the ORC system with special attention to actual net power output,thermal efficiency as well as back work ratio(BWR).The results showed that an increase in the pump speed led to an increase in the mass flow rate and expand in the operating range of the outlet pressure.The mass flow rate decreased nonlinearly with the increase of the outlet pressure from 0.22 to 2.41 MPa;the electric power consumption changed between 151.54 and 2409.34 W and the mechanical efficiency of the pump changed from 7.90%to 61.88%when the pump speed varied from 1160 to 2900 r/min.Furthermore,at lower pump specific speed the ORC system achieved higher thermal efficiency,which suggested that an ultra-low specific speed pump was a promising candidate for an ORC system.The results also suggested that the effects of condensation conditions on the pump performance decreased with the pump speed increasing and BWR was relatively sensitive to the condensation conditions,especially at low pump speed.展开更多
基金support by the Science and Technology Planning Project of Hebei Province,China(Grant No.15273703D)
文摘Diesel particulate matter(DPF) is usually employed to meet the stringent regulations on particulate matter(PM) emissions for diesel engine. To resolve the DPF regeneration problem, comprehensive information about the factors influencing PM oxidation behaviors must be understood. Large amounts of factors related to PM oxidation activity have been investigated, however, some relations are still ambiguous. This paper reviews the factors related to PM oxidation activity that the factors are divided into the engine-correlated and engine-uncorrelated factors. The methods with both advantages and disadvantages to test the oxidation behaviors are introduced. The microstructure and ingredient being fundamental factors affecting PM oxidation behaviors are as the principle line to correlate PM oxidation behaviors and engine-correlated factors. The relations of engine-correlated factors with oxidation behaviors are obtained though advanced technologies that are mutual complementation. The engine-uncorrelated factors are also reviewed that these factors are vital to oxidation activity changes. Multiple-factor analysis rather than single-factor analysis should be developed to make the oxidation behaviors of diesel PM more clear.
基金sponsored by the National Natural Science Foundation of China(Grant No.51776005)the National Key R&D Program of China(Grant No.2016YFE0124900)
文摘In an organic Rankine cycle(ORC)system,the working fluid pump plays an important role in the system performance.This paper focused on the operating characteristics of a multistage centrifugal pump at various speeds and condensation conditions.The experimental investigation was carried out to assess the influence of the performance of the pump by the ORC system with special attention to actual net power output,thermal efficiency as well as back work ratio(BWR).The results showed that an increase in the pump speed led to an increase in the mass flow rate and expand in the operating range of the outlet pressure.The mass flow rate decreased nonlinearly with the increase of the outlet pressure from 0.22 to 2.41 MPa;the electric power consumption changed between 151.54 and 2409.34 W and the mechanical efficiency of the pump changed from 7.90%to 61.88%when the pump speed varied from 1160 to 2900 r/min.Furthermore,at lower pump specific speed the ORC system achieved higher thermal efficiency,which suggested that an ultra-low specific speed pump was a promising candidate for an ORC system.The results also suggested that the effects of condensation conditions on the pump performance decreased with the pump speed increasing and BWR was relatively sensitive to the condensation conditions,especially at low pump speed.
