Combined cooling and power(CCP)system driven by low-grade heat is promising for improving energy efficiency.This work proposes a CCP system that integrates a regenerative organic Rankine cycle(RORC)and an absorption c...Combined cooling and power(CCP)system driven by low-grade heat is promising for improving energy efficiency.This work proposes a CCP system that integrates a regenerative organic Rankine cycle(RORC)and an absorption chiller on both driving and cooling fluid sides.The system is modeled by using the heat current method to fully consider nonlinear heat transfer and heat-work conversion constraints and resolve its behavior accurately.The off-design system simulation is performed next,showing that the fluid inlet temperatures and flow rates of cooling water as well as RORC working fluid strongly affect system performance.The off-design operation even becomes infeasible when parameters deviate from nominal values largely due to limited heat transfer capability of components,highlighting the importance of considering heat transfer constraints via heat current method.Design optimization aiming to minimize the total thermal conductance is also conducted.RORC efficiency increases by 7.9%and decreases by 12.4%after optimization,with the hot fluid inlet temperature increase from 373.15 to 403.15 K and mass flow rate ranges from 10 to 30 kg/s,emphasizing the necessity of balancing system cost and performance.展开更多
Based on the analysis of air flow and heat transfer in the dry-cooling towerfor Harmon system, a combined iteration method is presented to solve the coupled heat transfer anddraft equations derived from theoretical an...Based on the analysis of air flow and heat transfer in the dry-cooling towerfor Harmon system, a combined iteration method is presented to solve the coupled heat transfer anddraft equations derived from theoretical and empirical formulas, with the size of the exchangers andthe cooling tower or the systematic parameters being determined. Taking the 686 MW unit as anexample, the present calculating results are well agreed with those of the real case, and thus themethod presented is practical and feasible for reasonable design of Harmon system.展开更多
Objective： To observe the therapeutic effect of warm needling method for knee osteoarthritis. Methods： Three hundred cases were randomly divided into treatment group and control group, 150 cases respectively in each...Objective： To observe the therapeutic effect of warm needling method for knee osteoarthritis. Methods： Three hundred cases were randomly divided into treatment group and control group, 150 cases respectively in each group. The treatment group was treated by warm needling method, and the control group was treated by simple acupuncture. Their therapeutic effects were compared after 20 sessions of treatments. Results： The effective rate was 94.0% in the treatment group and 86.0% in the control group, with a significant difference between the two groups （P〈0.05）. Conclusion： The therapeutic effect is better in the warm needling group than in the control group in the treatment of knee osteoarthritis.展开更多
基金supported by National Natural Science Foundation of China(Grant No.52125604)。
文摘Combined cooling and power(CCP)system driven by low-grade heat is promising for improving energy efficiency.This work proposes a CCP system that integrates a regenerative organic Rankine cycle(RORC)and an absorption chiller on both driving and cooling fluid sides.The system is modeled by using the heat current method to fully consider nonlinear heat transfer and heat-work conversion constraints and resolve its behavior accurately.The off-design system simulation is performed next,showing that the fluid inlet temperatures and flow rates of cooling water as well as RORC working fluid strongly affect system performance.The off-design operation even becomes infeasible when parameters deviate from nominal values largely due to limited heat transfer capability of components,highlighting the importance of considering heat transfer constraints via heat current method.Design optimization aiming to minimize the total thermal conductance is also conducted.RORC efficiency increases by 7.9%and decreases by 12.4%after optimization,with the hot fluid inlet temperature increase from 373.15 to 403.15 K and mass flow rate ranges from 10 to 30 kg/s,emphasizing the necessity of balancing system cost and performance.
基金This project is supported by Main Project in Shanghai for the Combination of New technology and Production(No.9120902)Selected from Proceedings of 2000 the First International conference on Mechanical Engineering
文摘Based on the analysis of air flow and heat transfer in the dry-cooling towerfor Harmon system, a combined iteration method is presented to solve the coupled heat transfer anddraft equations derived from theoretical and empirical formulas, with the size of the exchangers andthe cooling tower or the systematic parameters being determined. Taking the 686 MW unit as anexample, the present calculating results are well agreed with those of the real case, and thus themethod presented is practical and feasible for reasonable design of Harmon system.
基金Planned Project of Shanghai Commission of Science and Technology (08DZ1973200)Scientific Research Fund for Chinese Medicine of Shanghai Municipal Health Bureau(2008L010A)
文摘Objective： To observe the therapeutic effect of warm needling method for knee osteoarthritis. Methods： Three hundred cases were randomly divided into treatment group and control group, 150 cases respectively in each group. The treatment group was treated by warm needling method, and the control group was treated by simple acupuncture. Their therapeutic effects were compared after 20 sessions of treatments. Results： The effective rate was 94.0% in the treatment group and 86.0% in the control group, with a significant difference between the two groups （P〈0.05）. Conclusion： The therapeutic effect is better in the warm needling group than in the control group in the treatment of knee osteoarthritis.
