Assessment and Analysis of Carrying Capacity of 350 km/h EMUs Operating on Beijing-Shanghai Highspeed Railway

This paper makes an analysis of the impact on the structure of the corridortype train working diagram by increasing the 350 km/h train pairs of Beijing-Shanghai High-speed Railway(HSR).According to the requirements of operation speed diversity,the multi-station receiving characteristics of cross-line trains and different train stopping schemes,this paper proposes a scheme of adding 350 km/h train pairs via computer analysis of carrying capability mode.The scheme is divided into three stages:(1)Initial stage:It is planned to increase trains running at 350 km/h,with 15~26 pairs of trains put into operation;(2)Rapid increase stage:27~142 pairs of 350 km/h trains are put into operation;(3)Full replacement stage:143~195 pairs of 350 km/h trains are put into operation,during which the number of cross-line trains under operation is controlled,the number of cross-line trains in each section is determined,the operation and connection scheme of cross-line trains is adjusted and the train stopping scheme is optimized.The results of this study were used for the adjustment of the train working diagram in the third quarter of June 25,2021 to increase the number of 350 km/h train pairs from 19 to 30 on Beijing-Shanghai HSR.350 km/h trains are evenly arranged during 7:00—19:00 on the train working diagram and 300 km/h trains are arranged by making full use of every time and space,to improve the travelling speed on Beijing-Shanghai HSR as a whole.

Estimation of Energy Consumption in COREX Process Using a Modified Rist Operating Diagram

Fuel consumption in the COREX-3000 process run in Baosteel is currently higher than the design index. Therefore, mass and heat balance equations for the COREX process were established using the basic principles in- cluded in the Rist operating diagram for blast furnace （BF） as a reference. Thermodynamic calculations were then used to modify the Rist operating diagram so that it was suitable for the COREX process. The modified Rist operating dia- gram was then applied for the evaluation of metallization rate （MR） and fuel structure to reduce the energy consump- tion in the COREX process. The modified Rist operating diagram for the shaft furnace （SF） provided a nearly ideal value for the restriction point W when the metallization rate was increased, while the point P on the operating line for the melter gasifier （MG） moved upward due to reduction in the heat required in hearth. The feasibility of reduc- ing the energy consumption during the COREX process by changing the fuel structure was also demonstrated.

The productivity of two serial chemostats

This paper considers the production of biomass of two interconnected chemostats in series with biomass mortality and a growth kinetic of the biomass described by an increasing function.A comparison is made with the productivity of a single chemostat with the same mortality rate and with volume equal to the sum of the volumes of the two chemostats.We determine the operating conditions under which the productivity of the serial configuration is greater than the productivity of the single chemostat.Moreover,the differences and similarities in the results corresponding to the case with mortality and the one without mortality,are highlighted.The mortality leads to surprising results where the productivity of a steady state where the bacteria are washed out in the first chemostat is greater than the one where the bacteria are present in both chemostats.

A mass and energy estimation for the hydrogen utilization in the iron-making process

The possibility of using hydrogen to lower CO 2 emissions in the iron-making process was confirmed by the heat and mass balances in the blast furnace operation. The mass and heat balances for hydrogen utilization in the blast furnace were estimated by using the basic concept of RIST operating diagram. In this study, the RIST operating diagram was modified to be suitable for representing the operation with respect to hydrogen, where the RIST operating diagram is a graphical representation of heat and mass balance in blast furnace operation. RIST operating diagram was applied here to some individual parameters of interest such as H 2 injection in blast furnace process to reduce coke (carbon consumption). It was observed that the point W moved to the right in the RIST operating diagram under the condition of increasing hydrogen injection at tuyere, which originates from the contribution of gas composition (O/H 2 ) equilibrated with Fe/FeO at a certain temperature. Point P also moved downward due to heat requirement with respect to hydrogen utilization, by which the new RIST operating diagram for hydrogen utilization was able to be constructed. Under the condition of hydrogen injection, the expected overall carbon consumption in the blast furnace decreased due to the contribution of hydrogen.

Interspecific density-dependent model of predator-prey relationship in the chemostat

The objective of this study is to analyze a model of competition for one resource in the chemostat with general interspecific density-dependent growth rates,taking into account the predator–prey relationship.This relationship is characterized by the fact that the prey species promotes the growth of the predator species which in turn inhibits the growth of the first species.The model is a three-dimensional system of ordinary differential equations.With the same dilution rates,the model can be reduced to a planar system where the two models have the same local and even global behavior.The existence and stability conditions of all steady states of the reduced model in the plane are determined according to the operating parameters.Using the nullcline method,we present a geometric characterization of the existence and stability of all equilibria showing the multiplicity of coexistence steady states.The bifurcation diagrams illustrate that the steady states can appear or disappear only through saddle-node or transcritical bifurcations.Moreover,the operating diagrams describe the asymptotic behavior of this system by varying the control parameters and show the effect of the inhibition of predation on the emergence of the bistability region and the reduction until the disappearance of the coexistence region by increasing this inhibition parameter.