To increase the efficiency and reliability of the thermodynamics analysis of the hydraulic system, the method based on pseudo-bond graph is introduced. According to the working mechanism of hydraulic components, they ...To increase the efficiency and reliability of the thermodynamics analysis of the hydraulic system, the method based on pseudo-bond graph is introduced. According to the working mechanism of hydraulic components, they can be separated into two categories: capacitive components and resistive components. Then, the thermal-hydraulic pseudo-bond graphs of capacitive C element and resistance R element were developed, based on the conservation of mass and energy. Subsequently, the connection rule for the pseudo-bond graph elements and the method to construct the complete thermal-hydraulic system model were proposed. On the basis of heat transfer analysis of a typical hydraulic circuit containing a piston pump, the lumped parameter mathematical model of the system was given. The good agreement between the simulation results and experimental data demonstrates the validity of the modeling method.展开更多
In general, the energy storage in facilities to intermittent sources is provided by a battery of accumulators. Having found that the duration of life of chemical accumulators is strongly shortened in the northern regi...In general, the energy storage in facilities to intermittent sources is provided by a battery of accumulators. Having found that the duration of life of chemical accumulators is strongly shortened in the northern regions of Cameroon and that this has a considerable impact on the operating costs and the reliability of power plants to intermittent sources, this work proposes to find an alternative to these chemical accumulators rendered vulnerable by the high temperatures. It reviews all energy storage techniques and makes a choice （the CAES （compressed air energy storage）） based on thermal robustness. It proposes a new technique of restitution of the energy by producing an artificial wind from the compressed air. The feedback loop thus obtained by the compressor-tank-wind subsystem is studied from a series of manipulations and its efficiency is determined. To automate the operation of this system, a controller is required. The operating logic of the controller is provided in function of the precise states of the load, the tank and the natural sources.展开更多
The European Union Framework Programme 71 Enerfish project aims to demonstrate a new poly-generation application with renewable energy sources for the fishery industry in Vietnam. The fish processing plant under consi...The European Union Framework Programme 71 Enerfish project aims to demonstrate a new poly-generation application with renewable energy sources for the fishery industry in Vietnam. The fish processing plant under consideration can be made by energy self-sufficient when all fish waste oil is processed into biodiesel and further converted to electricity and heat （for cooling） in a CHP （combined heat and power） unit. The purpose of the present paper is to discuss the profitability of such plants in southeast Asia. The economic model shows that electricity production is, due to the low electricity tariff, uneconomical （except during electricity blackout）, even if cogeneration heat can be utilized. This prompt a design of the plant whereby the necessary heat for the biodiesel process is taken from the waste heat produced by the compressors of a CO2 cooling system. According to the calculations and assumptions of the present study, the profitability of biodiesel production from fish cleaning wastes in Vietnam depends strongly on the market prices for fish waste and fish oil. Different business case scenarios are described.展开更多
基金Project(51175518)supported by the National Natural Science Foundation of China
文摘To increase the efficiency and reliability of the thermodynamics analysis of the hydraulic system, the method based on pseudo-bond graph is introduced. According to the working mechanism of hydraulic components, they can be separated into two categories: capacitive components and resistive components. Then, the thermal-hydraulic pseudo-bond graphs of capacitive C element and resistance R element were developed, based on the conservation of mass and energy. Subsequently, the connection rule for the pseudo-bond graph elements and the method to construct the complete thermal-hydraulic system model were proposed. On the basis of heat transfer analysis of a typical hydraulic circuit containing a piston pump, the lumped parameter mathematical model of the system was given. The good agreement between the simulation results and experimental data demonstrates the validity of the modeling method.
文摘In general, the energy storage in facilities to intermittent sources is provided by a battery of accumulators. Having found that the duration of life of chemical accumulators is strongly shortened in the northern regions of Cameroon and that this has a considerable impact on the operating costs and the reliability of power plants to intermittent sources, this work proposes to find an alternative to these chemical accumulators rendered vulnerable by the high temperatures. It reviews all energy storage techniques and makes a choice （the CAES （compressed air energy storage）） based on thermal robustness. It proposes a new technique of restitution of the energy by producing an artificial wind from the compressed air. The feedback loop thus obtained by the compressor-tank-wind subsystem is studied from a series of manipulations and its efficiency is determined. To automate the operation of this system, a controller is required. The operating logic of the controller is provided in function of the precise states of the load, the tank and the natural sources.
文摘The European Union Framework Programme 71 Enerfish project aims to demonstrate a new poly-generation application with renewable energy sources for the fishery industry in Vietnam. The fish processing plant under consideration can be made by energy self-sufficient when all fish waste oil is processed into biodiesel and further converted to electricity and heat （for cooling） in a CHP （combined heat and power） unit. The purpose of the present paper is to discuss the profitability of such plants in southeast Asia. The economic model shows that electricity production is, due to the low electricity tariff, uneconomical （except during electricity blackout）, even if cogeneration heat can be utilized. This prompt a design of the plant whereby the necessary heat for the biodiesel process is taken from the waste heat produced by the compressors of a CO2 cooling system. According to the calculations and assumptions of the present study, the profitability of biodiesel production from fish cleaning wastes in Vietnam depends strongly on the market prices for fish waste and fish oil. Different business case scenarios are described.
