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
The heat losses density in power electronics products follows an ever increasing trend. Nowadays they reach 200 W/cmz at chip level and 50 W/cm2 at heatsink base level. Water cooling is the most effective cooling meth...The heat losses density in power electronics products follows an ever increasing trend. Nowadays they reach 200 W/cmz at chip level and 50 W/cm2 at heatsink base level. Water cooling is the most effective cooling method but unfortunately water is often undesired due to high voltages or costumer requirements. Two-phase cooling is a promising technology for electronics cooling. It allows using dielectric fluids in passive systems and still benefits from very high heat transfer coefficients. Thermosyphons are a particularly interesting technology in the field of power electronics because it is entirely passive and a simple equipment. ABB has developed a compact thermosyphon heat exchanger based on automotive technology, which uses numerous multi-port extruded tubes with capillary sized channels disposed in parallel and brazed to a heated base plate in order to achieve the desired compactness. The experimental performances of this novel power electronics cooling system are presented with R134a as a working fluid. The influence of several parameters on the performances was studied experimentally： coolant flow rate, coolant temperature, heat load and fluid filling.展开更多
Waste heat recovery(WHR)is one of the most useful ways to improve the efficiency of internal combustion engines,and an electricity-cooling cogeneration system(ECCS)based on Rankin-absorption refrigeration combined cyc...Waste heat recovery(WHR)is one of the most useful ways to improve the efficiency of internal combustion engines,and an electricity-cooling cogeneration system(ECCS)based on Rankin-absorption refrigeration combined cycle for the WHR of gaseous fuel engines is proposed in the paper.This system can avoid wasting the heat in condenser so that the efficiency of the whole WHR system improves,but the condensing temperature of Rankin cycle(RC)must increase in order to use absorption refrigeration system,which leads to the decrease of RC output power.Therefore,the relationship between the profit of absorption refrigeration system and the loss of RC in this combined system is the mainly studied content in the paper.Because the energy quality of cooling and electricity are different,cooling power in absorption refrigeration is converted to corresponding electrical power consumed by electric cooling system,which is defined as equivalent electrical power.With this method,the effects of some important operation parameters on the performance of the ECCS are researched,and the equivalent efficiency,exergy efficiency and primary energy rate are compared in the paper.展开更多
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.
文摘The heat losses density in power electronics products follows an ever increasing trend. Nowadays they reach 200 W/cmz at chip level and 50 W/cm2 at heatsink base level. Water cooling is the most effective cooling method but unfortunately water is often undesired due to high voltages or costumer requirements. Two-phase cooling is a promising technology for electronics cooling. It allows using dielectric fluids in passive systems and still benefits from very high heat transfer coefficients. Thermosyphons are a particularly interesting technology in the field of power electronics because it is entirely passive and a simple equipment. ABB has developed a compact thermosyphon heat exchanger based on automotive technology, which uses numerous multi-port extruded tubes with capillary sized channels disposed in parallel and brazed to a heated base plate in order to achieve the desired compactness. The experimental performances of this novel power electronics cooling system are presented with R134a as a working fluid. The influence of several parameters on the performances was studied experimentally： coolant flow rate, coolant temperature, heat load and fluid filling.
基金supported by the National Basic Research Program of China("973"Project)(Gran No.2011CB707201)
文摘Waste heat recovery(WHR)is one of the most useful ways to improve the efficiency of internal combustion engines,and an electricity-cooling cogeneration system(ECCS)based on Rankin-absorption refrigeration combined cycle for the WHR of gaseous fuel engines is proposed in the paper.This system can avoid wasting the heat in condenser so that the efficiency of the whole WHR system improves,but the condensing temperature of Rankin cycle(RC)must increase in order to use absorption refrigeration system,which leads to the decrease of RC output power.Therefore,the relationship between the profit of absorption refrigeration system and the loss of RC in this combined system is the mainly studied content in the paper.Because the energy quality of cooling and electricity are different,cooling power in absorption refrigeration is converted to corresponding electrical power consumed by electric cooling system,which is defined as equivalent electrical power.With this method,the effects of some important operation parameters on the performance of the ECCS are researched,and the equivalent efficiency,exergy efficiency and primary energy rate are compared in the paper.
