84results about How to "Improve startup reliability" patented technology

The present invention relates to pumps comprising variable frequency drive means and methods for operating such pumps. The inventive method for operating a pump (1) comprises the steps of obtaining values of operating parameters of the pump (1) indicating pump conditions, communicating said values of operating parameters from variable frequency drive means (2) to a control device (11), determining if a predetermined condition is fulfilled, communicating instructions from the control device (11) to the variable frequency drive means (2), based on the fulfillment of said predetermined condition. Furthermore, a computer program product loadable into a memory of a digital computer device, including software code portions for performing the inventive method, a pump (1), a pump system and a control device (11) for a pump are described.

A gas turbine engine that includes a compressor, a combustion stage, a turbine assembly, a fuel gas feed system for supplying fuel gas to a combustion stage of the gas turbine, and an integrated fuel gas characterization system. The integrated fuel gas feed system can include a buffer tank. The integrated fuel gas characterization system for determining the amount of energy provided by the fuel prior to combustion of the fuel in the combustion stage. The integrated fuel gas characterization system minimizes megawatt swings by adjusting the operating parameters of the gas turbine engine based on the rate of change in fuel gas energy content. The integrated fuel gas characterization system also provides improved turbine engine start-up reliability by tuning the turbine engine operating parameters using fuel gas energy content measurements obtained prior to actual start-up.

A system and method for improving fuel cell system start-up reliability. The method includes determining if the resistance of the membranes in a fuel cell stack is too high, where the reliability of system start-up will be reduced, and if so, providing one or more remedial actions to help ensure that the start-up is more reliable. In one embodiment, the system and method determine that the fuel cell membranes are to dry based on whether a high frequency measurement of the fuel cell stack exceeds a predetermined HFR threshold. If the HFR threshold has been exceeded, a special start-up procedure is used that increases the reliability that the start-up will be successful using the remedial actions, such as reducing cathode airflow and turning on stack end cell heaters.

The present invention provides a fuel cell system including a fuel cell, a hydrogen gas pipe system for supplying a fuel gas to the fuel cell, and an injector for adjusting a pressure of the upstream side of the hydrogen gas pipe system to supply the hydrogen gas to the downstream side, wherein the injector includes an internal channel for communicating the upstream side of the injector with the downstream side of the injector, and a valve body movably arranged in the internal channel for switching a channel opening area in multiple stages corresponding to a movement position of the valve body, and wherein water at least around the valve body of the injector is reduced when the system stops.

A two-phase heat transfer device that is capillary-driven or gravity-driven, has a two-phase working fluid contained in a closed general circuit, including an evaporator, a condenser, a reservoir having an inner volume with a liquid portion and a gas portion, a first vapor communication circuit, and a second liquid phase communication circuit. The reservoir comprises a plurality of floating bodies separating the liquid portion from the gas portion, by means of which the heat exchanges between the liquid portion and the gas portion are slowed down, which allows to diminish the effect of movement of the liquid portion or of an influx of cold or warm liquid into the reservoir.

A burner includes a pilot burner, a combustion chamber, and a swirler located radially outwardly of the combustion chamber and being adapted to impose a swirling motion on a fuel/air mixture about an axial centerline of the combustion chamber. The pilot burner has a pilot burner face located radially inwardly of the swirler and forms an axially upstream wall of the combustion chamber, the pilot burner face incorporating a pilot fuel injector and an ignitor, both being positioned radially offset from the axial centerline. A recess is positioned radially offset from the axial centerline within the pilot burner face.

The invention discloses a magnetic levitation bearing control method and device, a storage medium, and a magnetic levitation system. The method comprises the following steps of determining whether thestarting torque required when a compressor in the magnetic levitation system is started exceeds preset torque or not; and if the starting torque required when the compressor is started exceeds the preset torque, increasing control parameters of the magnetic levitation system to control the control parameters of a magnetic levitation bearing to be adapted to the starting torque required when the compressor is started. According to the scheme disclosed by the invention, the problem that the starting torque is variable to affect the starting reliability can be solved so as to achieve the effectof improving the starting reliability.

The invention aims at providing a refrigerator capable of improving reliability of startup of a compressor and high energy saving. The refrigerator is provided with: a compressor connecting and pressing a refrigerant via a pipe which the refrigerant passes by, a condenser making the refrigerant output from the compressor in heat dissipation, a decompression device decompressing the refrigerant output from the condenser, freezing circulation of an evaporator evaporating the refrigerant output from the decompression device and cooling air, and a refrigerant flow adjustment device disposed between the condenser and the evaporator, and controlling the refrigerant flow in a pipe. The refrigerator is provided with a pressure prediction device, the pressure prediction device predicts pressure at an intake side and an exhaust side of the compressor based on evaporator temperature, condenser temperature, and external air temperature when the compressor stops, rotation number before the compressor stops, and any time or combination of time passed after the compressor stops, via the pressure prediction device, whether startup of the compressor is allowed is determined by the pressure prediction device, and the compressor is started under the condition of pressure.

The invention discloses a variable-frequency air-cooled screw water chilling unit and a variable-working-condition starting control method thereof. The variable working condition starting control method comprises the following steps that the initial frequency of a variable frequency fan and the initial frequency of a variable frequency compressor are controlled according to the interval where theenvironment temperature detected during starting is located; after the compressor is started for v seconds, the frequency of the variable frequency fan is adjusted according to the comparison result of the difference value of the high-pressure pressure and the low-pressure pressure and the first preset pressure and the comparison result of the low-pressure pressure and the second preset pressure;and after the compressor is started for n seconds, the frequency of the variable frequency compressor is adjusted according to the comparison result of the high-pressure pressure and the variable frequency fan closing pressure. The unit is provided with a high-low pressure sensor and an environment temperature sensor to adjust the frequency of the compressor or the frequency of the fan, and the purpose of optimizing the starting reliability of the compressor under different working conditions is achieved.

A system and method for improving fuel cell system start-up reliability. The method includes determining if the resistance of the membranes in a fuel cell stack is too high, where the reliability of system start-up will be reduced, and if so, providing one or more remedial actions to help ensure that the start-up is more reliable. In one embodiment, the system and method determine that the fuel cell membranes are too dry based on the time that has gone by since the last shut-down. If the time threshold has been exceeded, a special start-up procedure is used that increases the reliability that the start-up will be successful using the remedial actions, such as reducing cathode airflow and turning on stack end cell heaters.

The invention discloses a single-phase permanent magnet motor. The single-phase permanent magnet motor comprises a stator and a rotor which can rotate relative to the stator, wherein the stator comprises a stator magnetic core and a winding which is wound around the stator magnetic core; the stator magnetic core comprises an outer ring part, multiple tooth bodies which extend from the outer ring part to the inner side, and pole shoes which extend from the tail end of each tooth body to two sides circumferentially, wherein the rotor is accommodated in a space formed by the pole shoes in a surrounding manner; the rotor comprise multiple permanent magnetic poles arranged in the circumferential direction of the rotor; and the distances from the outer side surface of each permanent magnet pole to the rotor axis are gradually decreased from the circumferential center to the circumferential two sides, so that non-uniform air gaps, which are symmetrical around the middle line of the permanent magnetic poles, are formed between the outer side surfaces of the permanent magnetic poles and the inner circumferential surfaces of the pole shoes. By adoption of the single-phase permanent magnet motor, the starting reliability is improved, and starting dead points are reduced.

A single phase motor and a hair dryer are provided. The motor includes a stator and a rotor. The stator includes a stator core and a stator winding. The stator core includes an outer ring portion, teeth extending inwardly from the outer ring portion, and two pole shoes extending from a distal end of each tooth. A winding slot is formed between each two adjacent teeth. A slot opening is disposed between the pole shoes of the adjacent teeth, and is offset from one of the two adjacent teeth. The air supplying unit includes the single phase motor and an impeller. The startup angle and cogging torque of the motor are adjustable by adjusting the position/width of the slot opening, without the need of additional positioning slots or positioning holes defined at the pole shoes, which makes the motor structure simple.

A single phase permanent magnet motor includes a stator and a rotor rotatable relative to the stator. The stator includes a stator core and a winding wound around the stator core. The rotor includes a rotor core and a plurality of permanent magnetic poles. The stator core includes at least one first stator core lamination and at least one second stator core lamination stacked with the first stator core lamination. Inner structures of the first stator core lamination and the second stator core lamination are different. This structure reduces motor's vibration and noise, avoids possible startup dead point and improves the motor startup reliability.