The present invention relates to a vacuum pump, in particular to a turbomolecular pump, having at least one pump stage and having a pressure determination unit for determining a pressure present at a suction side of the vacuum pump, said pump comprising a measurement device, with a measurement tap of the measurement device being provided in the region of the pump stage or downstream of the pump stage.

A non-return valve with twin plugs is connected to a fluid reservoir and equipment that can receive a small overflow quantity essentially in the gaseous state from the reservoir. This occurs when the primary valve is open. In the case of a larger overflow essentially in the liquid state, the openings are switched over to evacuate the overflow to another outlet branch of the non-return valve, without it being transferred to the equipment. The invention is useful in an oil lubrication circuit, in which a hypothetical fuel leak into the oil could cause the oil reservoir to overflow into the non-return valve and in which a significant flow of liquid to the equipment must be avoided; oil outlet through the other branch of the outlet can remain in a reservoir provided with a drain system.

The present invention is directed to a direct-drive fan system and a variable process control system for efficiently managing the operation of fans in a cooling system such as a wet-cooling tower or air-cooled heat exchanger (ACHE), HVAC systems, mechanical towers or chiller systems. The present invention is based on the integration of key features and characteristics such as tower thermal performance, fan speed and airflow, motor torque, fan pitch, fan speed, fan aerodynamic properties, and pump flow. The variable process control system processes feedback signals from multiple locations in order control a high torque, variable speed, permanent magnet motor to drive the fan. Such feedback signals represent certain operating conditions including motor temperature, basin temperature, vibrations, and pump flow rates. Other data processed by the variable process control system in order to control the motor include turbine back pressure set-point, condenser temperature set-point and plant part-load setting. The variable process control system processes this data and the aforesaid feedback signals to optimize the operation of the cooling system in order to prevent disruption of the industrial process and prevent equipment (turbine) failure or trip. The variable process control system alerts the operators for the need to conduct maintenance actions to remedy deficient operating conditions such as condenser fouling. The variable process control system increases cooling for cracking crude and also adjusts the motor RPM, and hence the fan RPM, accordingly during plant part-load conditions in order to save energy.

The invention relates to a method of monitoring a start-up sequence of a turbomachine that comprises a compressor equipped with a rotor, a starter capable of driving the rotor in rotation and a combustion chamber. The start-up sequence comprises a first phase during which the starter increases the rotation speed of the rotor up to an instant at which fuel is injected into the turbomachine combustion chamber, and a second phase after the first phase that terminates when the starter stops driving the rotor. The method includes: acquisition (ACQ) of a signal representative of the rotation speed of the rotor during the start sequence; detection (DRP1, DRP2, INT) of an instant at which there is a sudden change in the variation of said signal with time, the sudden change instant thus detected being deemed to be the instant at which an air-fuel mix is ignited in the combustion chamber.

A method of determining an inlet total air pressure includes determining a first parameter indicative of a first inlet total air pressure. The method includes executing a sequence that includes: determining a mass air flow passing through the air inlet based on the first parameter, determining a Mach number of air passing through the air inlet based on the mass air flow, determining a static air pressure at the air inlet, determining an air pressure ratio based on the Mach number, generating a subsequent parameter indicative of the revised inlet total air pressure based on the air pressure ratio and the static air pressure, and substituting the subsequent parameter for the first parameter. The method includes executing at least one additional instance of the sequence with the subsequent parameter, and outputting the subsequent parameter as the inlet total air pressure.

A system for measuring turbulence of a flow of a turbine engine, notably of a turbine engine compressor includes a first housing with a first pressure sensor and a first inlet, a second housing with a second pressure sensor and a second inlet inclined relative to the first inlet, and a temperature sensor. The system is configured to calculate at least two orientation components of the velocity of the flow on the basis of the pressure sensors and the temperature sensor. The inlets are disposed at the vane foot, on the leading edge at the level of an internal shell.

Herein provided are methods and systems for setting a fuel flow schedule for starting a gas turbine engine of an aircraft. Aircraft speed and engine rotational speed are obtained. A compressor inlet recovered pressure is estimated by combining a first component influenced by the aircraft speed and a second component influenced by the engine rotational speed, and a fuel flow schedule is selected for engine start in accordance with the estimated compressor inlet recovered pressure.

A compressor water-wash advisory system generates compressor water-wash notifications or initiates on-line water-wash cycles for a gas turbine or turbofan jet engine based on monitored health parameters of the engine. A high-fidelity model of engine compressor performance defines nominal expected values of engine performance parameters, such as compressor efficiency and air flow, as a function of current operating conditions. A tracking filter component compares the modeled performance parameters with actual calculated performance parameters obtained from sensor data, and maintains a separate actual model of engine performance that modifies the nominal performance parameter values to match the calculated parameter values using parameter modifiers. A health index is derived as a function of the parameter modifiers, and a water-wash notification is generated when the health index is indicative of a significant loss of fuel efficiency due to dirt accumulation in the engine's compressor.

A flow volume measurement device for a turbo compressor includes a first pressure guide tube communicating with an intake pipe connected to a second compression stage having a compressor impeller that compresses a gas; and a second pressure guide tube communicating with an intake port of the second compression stage, which has a smaller internal diameter than an internal diameter of the intake pipe, and measures the flow volume of the gas on the basis of a difference in pressure between the first pressure guide tube and the second pressure guide tube.

A method for detecting a rotating stall includes: determining a level of variation of a static pressure in a combustion chamber of the turbojet engine around an average value of this static pressure; comparing the level of variation of the static pressure relative to a first threshold; comparing a temperature measured at the outlet of a turbine of the turbojet engine relative to a second threshold; and if the level of variation of the static pressure is greater than the first threshold and the temperature at the outlet of the turbine is greater than the second threshold, detecting a presence of a rotating stall.