With the analysis on regulating system in 200 MW steam turbine, the necessity of appending the fast-opening function to the original system is set forth and a new type of fast-opening mechanism is devised. The mathema...With the analysis on regulating system in 200 MW steam turbine, the necessity of appending the fast-opening function to the original system is set forth and a new type of fast-opening mechanism is devised. The mathematical model of system is built up. With the use of AMESIM software, the displacement curve of the piston, the force curve of the cartridge valve spool, the pressure curve and the flux curve in the regulation process are obtained based on simulation. The performances of three fast-opening systems composed of cartridge valves with different diameters are compared. Based on the analysis on factors that affect the execution time of fast-opening, the dead zone of the fast-opening system is put forward. To overcome the defect, dif- ferent operation modes are adopted for different zones. The result shows that with the increase of the valve diameter, the regulating time in the dead zone significantly exceeds the fast-opening time in the whole journey. Accordingly, the optimization operation tactic in the dead zone and the qualification conditions are brought forward. The fast-opening system composed of 32 mm cartridge valves is taken as an example with use of the tactic. The simulation result shows that the maximum regulating time is shortened by 509 ms.展开更多
With the increase of mining depth, the temperature of the original rock in deep mines increases. High temperature heat hazards at working surfaces and driving faces are becoming increasingly more serious. Given the pr...With the increase of mining depth, the temperature of the original rock in deep mines increases. High temperature heat hazards at working surfaces and driving faces are becoming increasingly more serious. Given the problem of mine cooling technologies at China and abroad and the actual conditions of a coal mine, we developed HEMS （High Temperature Exchange Machinery System） with inrushing mine water as the source of cold energy. Combined with the characteristics of a shortage of inrushing water in the coal mine, we proposed the Sanhejian model of HEMS with its lack of a cold source. The cooling engineer- ing construction, given the present conditions in the Sanhejian Coal Mine, consisted of two phases. In phase 1 horizontal water circulation was used as cold energy, while phase II was the geothermal utiliza- tion project. For the key equipment of HEMS-PT or HEMS-T, we provided the operational principle from theory and an actual application. Finally, we analyzed the operational effect of HEMS. After cooling, the temperature at the working face was below 30 ~C, which meets the national regulations. This system opens up new technology to solve the problem of deep mine heat hazards, which makes good sense in energy conservation and pollution reduction, improves the environment and realizes sustainable eco- nomic development.展开更多
CO2 （carbon dioxide） emission reduction, especially removal from coal-fired power plants has become the highest priority in measures to combat global warming. In China, coal-fired power is the main generating electr...CO2 （carbon dioxide） emission reduction, especially removal from coal-fired power plants has become the highest priority in measures to combat global warming. In China, coal-fired power is the main generating electricity style; more than 2,000 millions tons coal has been consumed in coal-fired power plants in China. In order to control CO2 emission, three technologies has been introduced, CCS （carbon capture and storage）, oxy-combusion, and IGCC （integrated gasification combined cycle）. CCS and IGCC technologies are expensive and need too many facilities; besides, there are some concrete problems need to resolve on the oxy-combustion technology. The energy saving work is the other pattern of CO2 emission control.展开更多
基金Project (No. NCET-04-0545) supported by the "New Century Elitist Supporting Plan" Fund Project of Education Ministry of China
文摘With the analysis on regulating system in 200 MW steam turbine, the necessity of appending the fast-opening function to the original system is set forth and a new type of fast-opening mechanism is devised. The mathematical model of system is built up. With the use of AMESIM software, the displacement curve of the piston, the force curve of the cartridge valve spool, the pressure curve and the flux curve in the regulation process are obtained based on simulation. The performances of three fast-opening systems composed of cartridge valves with different diameters are compared. Based on the analysis on factors that affect the execution time of fast-opening, the dead zone of the fast-opening system is put forward. To overcome the defect, dif- ferent operation modes are adopted for different zones. The result shows that with the increase of the valve diameter, the regulating time in the dead zone significantly exceeds the fast-opening time in the whole journey. Accordingly, the optimization operation tactic in the dead zone and the qualification conditions are brought forward. The fast-opening system composed of 32 mm cartridge valves is taken as an example with use of the tactic. The simulation result shows that the maximum regulating time is shortened by 509 ms.
基金Financial support for this project, provided by the Key Basic Research Program of China (No.2006CB202200)the National Major Project of Ministry of Education (No.304005)the Program for Changjiang Scholars and Innovative Research Team in University of China (No.IRT0656)
文摘With the increase of mining depth, the temperature of the original rock in deep mines increases. High temperature heat hazards at working surfaces and driving faces are becoming increasingly more serious. Given the problem of mine cooling technologies at China and abroad and the actual conditions of a coal mine, we developed HEMS （High Temperature Exchange Machinery System） with inrushing mine water as the source of cold energy. Combined with the characteristics of a shortage of inrushing water in the coal mine, we proposed the Sanhejian model of HEMS with its lack of a cold source. The cooling engineer- ing construction, given the present conditions in the Sanhejian Coal Mine, consisted of two phases. In phase 1 horizontal water circulation was used as cold energy, while phase II was the geothermal utiliza- tion project. For the key equipment of HEMS-PT or HEMS-T, we provided the operational principle from theory and an actual application. Finally, we analyzed the operational effect of HEMS. After cooling, the temperature at the working face was below 30 ~C, which meets the national regulations. This system opens up new technology to solve the problem of deep mine heat hazards, which makes good sense in energy conservation and pollution reduction, improves the environment and realizes sustainable eco- nomic development.
文摘CO2 （carbon dioxide） emission reduction, especially removal from coal-fired power plants has become the highest priority in measures to combat global warming. In China, coal-fired power is the main generating electricity style; more than 2,000 millions tons coal has been consumed in coal-fired power plants in China. In order to control CO2 emission, three technologies has been introduced, CCS （carbon capture and storage）, oxy-combusion, and IGCC （integrated gasification combined cycle）. CCS and IGCC technologies are expensive and need too many facilities; besides, there are some concrete problems need to resolve on the oxy-combustion technology. The energy saving work is the other pattern of CO2 emission control.
