37results about How to "Reduce the rise" patented technology

The present invention relates to a battery separator comprising a polyolefin porous film and a heat-resistant porous layer provided on at least one surface of the polyolefin porous film, the heat-resistant porous layer comprising barium sulfate particles and an organic synthetic resin component, the content of the barium sulfate particles, the increase in gas resistance per 1 [mu] m thickness of the heat-resistant porous layer, the shrinkage rate when left to stand for 1 hour in a 130 DEG C atmosphere, and the hydrogen sulfide concentration are within predetermined ranges.

The invention belongs to a water curtain box for ammonia gas absorption of a livestock breeding house. The water curtain box comprises a box body and a water curtain box base arranged at the bottom of the box body, the box body is provided with front aerating plates and lateral aerating plates, a water inlet and a water outlet are arranged below the lateral aerating plates, the bottom of the box body is provided with a water sink, an annular water channel is arranged on the periphery of the water sink, wet curtain plates are arranged in the annular water channel, an annular water pipe is arranged on the upper sides of the wet curtain plates, the bottom of the annular water pipe is provided with water holes, and an axial fan, a floater switch and an air cooler water pump are arranged at the inner bottom of the box body. The water curtain box base comprises a bottom plate, vertical plates and surface plates. The wet curtain plates are arranged on the periphery of the water curtain box, water in the water sink cyclically flows in the wet curtain plates via the axial fan and the air cooler water pump, ammonia gas is repeatedly absorbed, concentration of the ammonia gas in the breeding house is effectively reduced, growth speed and feed conservation ratio of livestock are increased, disease rate of the livestock is decreased, cost of enterprises is saved, and environmental pollution caused by discharge of the ammonia gas is avoided.

A high-shear fiber breaker for separating fiber beam and fiber fragment from paper stuff is provided. It contains shelf, dynamic units and multilevel operate units. Each unit contains helical delivery area in beck body and major work area. Helical delivery area contains constant screw stem on screw shaft. One end of constant screw stem connects with major work area. Beck body wall related to another end has a feed head. Major work area contains a series of vary screw stem on the square screw shaft. Vary screw stem arranges forward and reverse independent. Path with unloading valve for connecting with the next grade operating units is set on beck body in center of axial direction of major work area. A raw of filtration pore with filtrate receiver is set under the beck body wall in axial direction of vary screw stem.

The invention relates to a direct-current (DC) side voltage balance control method for a chain type static synchronous compensator, belonging to the field of power distribution control technologies. According to the method, the basic steps for controlling DC side voltage balance by a control circuit are as follows: the trigger pulse width of each H bridge is obtained by a master control CPU (Central Processing Unit) according to real-time acquired signals; a corresponding sequence relationship table is stored in a programmable logic controller (PLC); DC side voltage signals acquired in real time are subjected to real-time sequencing; a corresponding trigger pulse width sequence is obtained from the corresponding sequence relationship table according to the real-time sequencing; and each trigger pulse width is sequentially output to corresponding H bridges according to the trigger pulse width sequence to be used for controlling the on / off of full-controlled power electronic devices of all the H bridges as required. According to the DC side voltage balance control method for the chain type static synchronous compensator, the widest trigger pulse is allocated to the H bridge with the lowest DC side capacitance voltage currently, and the narrowest trigger pulse is allocated to the H bridge with the highest DC side capacitance voltage currently, so that the DC side capacitance voltage of all the H bridges can be favorably balanced as soon as possible.

PROBLEM TO BE SOLVED: To reduce temperature rise of three-phase induction motor during decanter start compared with base start method.SOLUTION: A start method of three-phase induction motor for accelerating rotation of the bowl of a decanter type centrifugal separator from stop state toward a target speed, starts the three-phase induction motor while cutting off the waveform of a voltage supplied from a power supply to the three-phase induction motor by means of a thyristor, in a state where the power supply and three-phase induction motor are electrically connected in star, and when the effective value of the current of the three-phase induction motor descends during start, conduction angle of the thyristor is increased.SELECTED DRAWING: Figure 4

The invention overcomes the technical defect that the existing two-level voltage source converter does not have the self-clearing capability of DC faults, and provides a DC fault self-clearing circuit for the two-level voltage source converter. The invention includes a zero-crossing shutdown circuit, a current limiting circuit, a first resonance generating circuit and a second resonance generating circuit. The invention has a simple structure and can realize the self-clearing of the DC fault without tripping the circuit breaker on the AC side. At the same time, since the response time of the circuit components is shorter than that of the AC circuit breaker, the rising range of the fault current is reduced, and the current stress of each component of the two-level voltage source converter is effectively reduced.

The embodiment of the invention discloses a protection device for a direct-current distribution network and a protection method thereof, wherein the direct-current distribution network comprises an inverter and a multi-stage power distribution device; the protection device for the direct-current distribution network comprises a current limiting module, wherein the input end of the inverter is electrically connected with a power supply end of the direct-current distribution network; the input end of the current limiting module is electrically connected with the output end of the inverter; the incoming end of the first-stage power distribution device is electrically connected with the output end of the current limiting module; the current limiting module is used to limit the output current of the current limiting module to be a second preset current when the output current of the current limiting module is greater than a first preset current and to control the input end and the output end of the current limiting module in a current direct-connection state when it is monitored that the output current of the current limiting module is smaller than a third preset current. The technicalscheme provided by the embodiment of the invention can improve the reliability of power supply of the direct-current distribution network and avoid the situation that one part breaks down and the whole network is paralyzed.