This work presents a thermal modeling of a new cold-start system technology designed for Otto cycle combustion based on the electromagnetic heating principle. Firstly, the paper presents a state-of-the-art review and ...This work presents a thermal modeling of a new cold-start system technology designed for Otto cycle combustion based on the electromagnetic heating principle. Firstly, the paper presents a state-of-the-art review and presents the context of automobile industry where heated injectors are necessary. The novel method of electromagnetic heating principle to solve the cold-start problem is still in the development phase and it enables engine starting at low temperatures in vehicles powered by ethanol or flex-fuel vehicles (FFV). This new system technology should be available as an alternative to replace the existing system. Currently, the cold-start system uses an auxiliary gasoline tank, which brings some inconvenience for the user. Secondly, the aim was also to create a physical model that takes into consideration all the parameters involved on the heating process such as power heating and average heat transfer coefficient. The study is based on the lumped system theory to model the ethanol heating process. From the analysis, two ordinary differential equations arise, which allowed an analytical solution. Particularly, an ethanol heating curve inside the injector was obtained, an important parameter in the process. Comparison with experimental data from other authors is also provided. Finally, a sensitivity analysis of controlling parameters such as heating power and heat transfer coefficient variation. The paper is concluded with suggestions for further studies.展开更多
Hydrogen as an energy carrier represents one of the most promising carbon-free energy solutions.The ongoing development of power-to-gas(Pt G)technologies that supports large-scale utilization of hydrogen is therefore ...Hydrogen as an energy carrier represents one of the most promising carbon-free energy solutions.The ongoing development of power-to-gas(Pt G)technologies that supports large-scale utilization of hydrogen is therefore expected to support hydrogen economy with a final breakthrough.In this paper,the economic performance of a MW-sized hydrogen system,i.e.a composition of water electrolysis,hydrogen storage,and fuel cell combined heat and power plant(FCCHP),is assessed as an example of hydrogen-based bidirectional electrical energy storage(EES).The analysis is conducted in view of the Danish electricity spot market that has high price volatility due to its high share of wind power.An economic dispatch model is developed as a mixed-integer programming(MIP)problem to support the estimation of variable cost of such a system taking into account a good granularity of the technical details.Based on a projected technology improvement by 2020,sensitivity analysis is conducted to illustrate how much the hydrogen-based EES is sensitive to variations of the hydrogen price and the capacity of hydrogen storage.展开更多
基金supported by Continental Indústria Automotiva Ltda
文摘This work presents a thermal modeling of a new cold-start system technology designed for Otto cycle combustion based on the electromagnetic heating principle. Firstly, the paper presents a state-of-the-art review and presents the context of automobile industry where heated injectors are necessary. The novel method of electromagnetic heating principle to solve the cold-start problem is still in the development phase and it enables engine starting at low temperatures in vehicles powered by ethanol or flex-fuel vehicles (FFV). This new system technology should be available as an alternative to replace the existing system. Currently, the cold-start system uses an auxiliary gasoline tank, which brings some inconvenience for the user. Secondly, the aim was also to create a physical model that takes into consideration all the parameters involved on the heating process such as power heating and average heat transfer coefficient. The study is based on the lumped system theory to model the ethanol heating process. From the analysis, two ordinary differential equations arise, which allowed an analytical solution. Particularly, an ethanol heating curve inside the injector was obtained, an important parameter in the process. Comparison with experimental data from other authors is also provided. Finally, a sensitivity analysis of controlling parameters such as heating power and heat transfer coefficient variation. The paper is concluded with suggestions for further studies.
基金the financial support of Innovation Fund Denmark through Project 3045-00012B
文摘Hydrogen as an energy carrier represents one of the most promising carbon-free energy solutions.The ongoing development of power-to-gas(Pt G)technologies that supports large-scale utilization of hydrogen is therefore expected to support hydrogen economy with a final breakthrough.In this paper,the economic performance of a MW-sized hydrogen system,i.e.a composition of water electrolysis,hydrogen storage,and fuel cell combined heat and power plant(FCCHP),is assessed as an example of hydrogen-based bidirectional electrical energy storage(EES).The analysis is conducted in view of the Danish electricity spot market that has high price volatility due to its high share of wind power.An economic dispatch model is developed as a mixed-integer programming(MIP)problem to support the estimation of variable cost of such a system taking into account a good granularity of the technical details.Based on a projected technology improvement by 2020,sensitivity analysis is conducted to illustrate how much the hydrogen-based EES is sensitive to variations of the hydrogen price and the capacity of hydrogen storage.
