A short review for the existing various driving methods for belt conveyor was given, which include the analysis and comparison about the advantages, disadvantages and suitable application range of these methods. Based...A short review for the existing various driving methods for belt conveyor was given, which include the analysis and comparison about the advantages, disadvantages and suitable application range of these methods. Based on this the vari-able-frequency-control(VFC) method for belt conveyor drive was fully discussed with focus on its application in medium-high voltage range. The principle of Neutral Point Clamped (NPC) Three-Level Inverter using high-voltage IGBTs together with the control strategy of rotor field-oriented vector control for induction motor drive were illustrated.展开更多
The main fan diffuser in a coal mine is an energy-recycling equipment with a dynamic energy loss for the main fan. Engineering practices and related researches show that the body structures of three types of diffusers...The main fan diffuser in a coal mine is an energy-recycling equipment with a dynamic energy loss for the main fan. Engineering practices and related researches show that the body structures of three types of diffusers are irrational. To solve the problem, an energy-saving diffuser is designed on the basis of the velocity potential theory. Under conditions of inlet velocity from 7 m/s to 32 m/s, 7 condition experiments using the energy-saving diffuser of 2.31 AER （area-enlarging ratio） and 5 condi- tion experiments using the energy-saving diffuser of 2.00 AER were conducted. Through a comparative analysis of the experi- ments, the results show that the COP （coefficient of performance） of the energy-saving diffuser of 2.31 AER is better than that of the energy-saving diffuser of 2.00 AER.展开更多
文摘A short review for the existing various driving methods for belt conveyor was given, which include the analysis and comparison about the advantages, disadvantages and suitable application range of these methods. Based on this the vari-able-frequency-control(VFC) method for belt conveyor drive was fully discussed with focus on its application in medium-high voltage range. The principle of Neutral Point Clamped (NPC) Three-Level Inverter using high-voltage IGBTs together with the control strategy of rotor field-oriented vector control for induction motor drive were illustrated.
文摘The main fan diffuser in a coal mine is an energy-recycling equipment with a dynamic energy loss for the main fan. Engineering practices and related researches show that the body structures of three types of diffusers are irrational. To solve the problem, an energy-saving diffuser is designed on the basis of the velocity potential theory. Under conditions of inlet velocity from 7 m/s to 32 m/s, 7 condition experiments using the energy-saving diffuser of 2.31 AER （area-enlarging ratio） and 5 condi- tion experiments using the energy-saving diffuser of 2.00 AER were conducted. Through a comparative analysis of the experi- ments, the results show that the COP （coefficient of performance） of the energy-saving diffuser of 2.31 AER is better than that of the energy-saving diffuser of 2.00 AER.
