20140052393 | METHOD FOR DETERMINING SPATIAL LOCATION OF CONDUCTING WIRE AND AERIAL EARTH WIRE OF POWER TRANSMISSION LINE - Disclosed is a method for determining the spatial location of a conducting wire and an aerial earth wire of a power transmission line, so as to solve the problem that the method in the prior art is not applicable to determining the spatial location of the conducting wire and the aerial earth wire of the conventional power transmission line with respect to lightning shielding failures. In the present invention, according to the physical locations of the conducting wires and aerial earth wires, the power transmission line shielding efficiency is calculated based on that the corresponding lightning shielding failure trip rate is zero when the exposure arc is zero, thus providing designing and operating units with a reliable analytical method for preventing lightning shielding failures, and meanwhile working out the shielding efficiency of the conducting wire of each phase more accurately, so as to analyze the structural relations between the aerial earth wires and conducting wires to determine the lightning protection effect of the whole power transmission line. The present invention provides a supplementary analytical method of the shielding efficiency of the existing power transmission lines. | 02-20-2014 |
20140033715 | MAIN STREAM TEMPERATURE CONTROL SYSTEM FOR LARGE BOILER - A main stream temperature control system for a large boiler comprises a PID module, A/D converters (M2, M3, M4, and M5), D/A converters (M6 and M7), electrical water spray adjusting valves (AA101 and AA102) and main stream temperature sensors (T1, T2, T3, and T4) for the boiler. The system uses a function module (f (x)), a differential module, a division module, multiplication modules (F1 and F2), addition and subtraction modules (J1, J2, J3, and J4), set value modules (K1-K6), selection modules (N1 and N2), a time pulse module (S1) and small value comparison modules (Z1 and Z2) in a distributed control system, so as to construct a real-time online optimized circuit and form an independent automatic control system for dynamic tracking and stable control, thereby increasing the thermal economic index of the boiler, and achieving the objective of energy saving and emission reduction. | 02-06-2014 |