Boiler fan is the main power consumption device in thermal power units and the induced draft fan accounted for the largest proportion. Reducing the energy consumption rate of induced draft fan is the main path to redu...Boiler fan is the main power consumption device in thermal power units and the induced draft fan accounted for the largest proportion. Reducing the energy consumption rate of induced draft fan is the main path to reduce the power consumption rate of thermal power units. The induce fan driven by small turbine is greatly effective for reducing the power consumption rate and the supply coal consumption rate in large thermal power plant. Take 1000 MW power units for example, the selection of steam source for steam turbine were discussed and economic performance of the unit under different steam source was compared in this paper. The result shows that compared with the motor driven method, there is about 1.6 g/kWh decrease in supply coal consumption rate driven by the fourth stage extraction steam;whereas there is about 2.5 g/kWh decrease in supply coal consumption rate driven by the fifth stage extraction steam.展开更多
The lignite pre-drying process plays an important role in modern lignite power plants and the fluidized bed dryer with internal heat utilization is a promising drying method which has both high efficiency and cost-eff...The lignite pre-drying process plays an important role in modern lignite power plants and the fluidized bed dryer with internal heat utilization is a promising drying method which has both high efficiency and cost-effectiveness. After conducting an in-depth analysis of a typical lignite pre-drying power plant, this work proposed a novel lignite pre-drying system with low-grade heat integration. Through system integration, the low-temperature evaporation of the lignite was recovered to heat the combustion air, while the residual heat from the flue gases was used to heat the feed or condensed water, thereby saving a portion of heat from the steam bleeds of the high and intermediate pressure turbines. The results for a1,000 MW lignite-fired power plant showed that, the proposed pre-drying system could yield an increase in net plant efficiency of approximately 3.6 % points and a reduction in the cost of electricity of $1.83/(MW h). The thermodynamic and economic performances were each superior to those of the existing pre-drying system, convincingly demonstrating that the research of this paper may provide a promising integrated lignite pre-drying method for the next-generation of lignite-fired power plants.展开更多
Genuine leather is often coated before making daily necessities such as shoes,clothing,bags,sofas,car seats,etc.,so as to impart leather products various colours,higher wear resistance and water resistance and so on.H...Genuine leather is often coated before making daily necessities such as shoes,clothing,bags,sofas,car seats,etc.,so as to impart leather products various colours,higher wear resistance and water resistance and so on.However,the coating of these products is often damaged in daily use which will decrease its aesthetic effect and practicability.Therefore,how to improve the scratch resistance of leather coatings has been puzzling people all the time.It is a common knowledge that animals and plants can repair the injured biological tissues by himself.According to this principle,here,we prepared a type of self-healing water-borne polyurethane with disulfide bond in the main chain by using HEDS as chain extender,and the self-healing system was triggered by the disulfide bonds with the help of shape memory function of waterborne Polyurethane,self-healing experiments how that the damaged of leather coating can be repaired fully at 60℃ for 12 h.展开更多
文摘Boiler fan is the main power consumption device in thermal power units and the induced draft fan accounted for the largest proportion. Reducing the energy consumption rate of induced draft fan is the main path to reduce the power consumption rate of thermal power units. The induce fan driven by small turbine is greatly effective for reducing the power consumption rate and the supply coal consumption rate in large thermal power plant. Take 1000 MW power units for example, the selection of steam source for steam turbine were discussed and economic performance of the unit under different steam source was compared in this paper. The result shows that compared with the motor driven method, there is about 1.6 g/kWh decrease in supply coal consumption rate driven by the fourth stage extraction steam;whereas there is about 2.5 g/kWh decrease in supply coal consumption rate driven by the fifth stage extraction steam.
基金supported by the National Major Fundamental Research Program of China(2011CB710706)the National Natural Science Foundation of China(51025624)the Fundamental Research Funds for the Central Universities(2014ZD04,2014XS35)
文摘The lignite pre-drying process plays an important role in modern lignite power plants and the fluidized bed dryer with internal heat utilization is a promising drying method which has both high efficiency and cost-effectiveness. After conducting an in-depth analysis of a typical lignite pre-drying power plant, this work proposed a novel lignite pre-drying system with low-grade heat integration. Through system integration, the low-temperature evaporation of the lignite was recovered to heat the combustion air, while the residual heat from the flue gases was used to heat the feed or condensed water, thereby saving a portion of heat from the steam bleeds of the high and intermediate pressure turbines. The results for a1,000 MW lignite-fired power plant showed that, the proposed pre-drying system could yield an increase in net plant efficiency of approximately 3.6 % points and a reduction in the cost of electricity of $1.83/(MW h). The thermodynamic and economic performances were each superior to those of the existing pre-drying system, convincingly demonstrating that the research of this paper may provide a promising integrated lignite pre-drying method for the next-generation of lignite-fired power plants.
基金supported by the National Key Research and Development Program of China(Project No:2017YFB0308600).
文摘Genuine leather is often coated before making daily necessities such as shoes,clothing,bags,sofas,car seats,etc.,so as to impart leather products various colours,higher wear resistance and water resistance and so on.However,the coating of these products is often damaged in daily use which will decrease its aesthetic effect and practicability.Therefore,how to improve the scratch resistance of leather coatings has been puzzling people all the time.It is a common knowledge that animals and plants can repair the injured biological tissues by himself.According to this principle,here,we prepared a type of self-healing water-borne polyurethane with disulfide bond in the main chain by using HEDS as chain extender,and the self-healing system was triggered by the disulfide bonds with the help of shape memory function of waterborne Polyurethane,self-healing experiments how that the damaged of leather coating can be repaired fully at 60℃ for 12 h.
