Supercritical water gasification is a clean technology for biomass conversion and utilization.In supercritical water gasification systems,H_(2)O is often used as the transport medium.Decreases in the reaction temperat...Supercritical water gasification is a clean technology for biomass conversion and utilization.In supercritical water gasification systems,H_(2)O is often used as the transport medium.Decreases in the reaction temperature at the gasification area and in the heating rate of biomass may limit the gasification rate and efficiency.In this paper,CO_(2)is used as the transport medium due to its relatively low critical point and specific heat capacity.Moreover,a corn stalk gasification system with different transport media is established in this paper,and the influences of various operating parameters,such as temperature,pressure and feedstock concentration,are investigated.The results show that the gas yield in the CO_(2)-transport system decreases by no more than 5 wt%.In addition,thermodynamic analysis reveals that a system with CO_(2)as transport medium consumes approximately 25%less electricity than a system with H_(2)O as the transport medium.In addition,the reaction heat absorption decreases.The results show the superiority of CO_(2)to H_(2)O as a transport medium.展开更多
The thermodynamic(energy and exergy)analysis of a condensate heating system,its segments,and components from a marine steam propulsion plant with steam reheating is performed in this paper.It is found that energy anal...The thermodynamic(energy and exergy)analysis of a condensate heating system,its segments,and components from a marine steam propulsion plant with steam reheating is performed in this paper.It is found that energy analysis of any condensate heating system should be avoided because it is highly influenced by the measuring equipment accuracy and precision.All the components from the observed marine condensate heating system have energy destructions lower than 3 kW,while the energy efficiencies of this system are higher than 99%.The exergy efficiency of closed condensate heaters continuously increases from the lowest to the highest steam pressures(from 70.10%to 92.29%).The ambient temperature variation between 5℃and 45℃notably influences the exergy efficiency change of both low pressure heaters and the low pressure segment equal to 31.61%,12.37%,and 18.35%,respectively.展开更多
基金National Key R&D Program of China(Grant No.2020YFA0714400).
文摘Supercritical water gasification is a clean technology for biomass conversion and utilization.In supercritical water gasification systems,H_(2)O is often used as the transport medium.Decreases in the reaction temperature at the gasification area and in the heating rate of biomass may limit the gasification rate and efficiency.In this paper,CO_(2)is used as the transport medium due to its relatively low critical point and specific heat capacity.Moreover,a corn stalk gasification system with different transport media is established in this paper,and the influences of various operating parameters,such as temperature,pressure and feedstock concentration,are investigated.The results show that the gas yield in the CO_(2)-transport system decreases by no more than 5 wt%.In addition,thermodynamic analysis reveals that a system with CO_(2)as transport medium consumes approximately 25%less electricity than a system with H_(2)O as the transport medium.In addition,the reaction heat absorption decreases.The results show the superiority of CO_(2)to H_(2)O as a transport medium.
基金This research is supported by the Croatian Science Foundation under the project IP-2018-01-3739,CEEPUS network CIII-HR-0108,European Regional Development Fund under the grant KK.01.1.1.01.0009(DATACROSS)project CEKOM under the grant KK.01.2.2.03.0004,CEI project“COVIDAi”(305.6019-20)University of Rijeka Scientific Grants uniri-tehnic-18-275-1447,uniritehnic-18-18-1146 and uniri-tehnic-18-14.
文摘The thermodynamic(energy and exergy)analysis of a condensate heating system,its segments,and components from a marine steam propulsion plant with steam reheating is performed in this paper.It is found that energy analysis of any condensate heating system should be avoided because it is highly influenced by the measuring equipment accuracy and precision.All the components from the observed marine condensate heating system have energy destructions lower than 3 kW,while the energy efficiencies of this system are higher than 99%.The exergy efficiency of closed condensate heaters continuously increases from the lowest to the highest steam pressures(from 70.10%to 92.29%).The ambient temperature variation between 5℃and 45℃notably influences the exergy efficiency change of both low pressure heaters and the low pressure segment equal to 31.61%,12.37%,and 18.35%,respectively.
