A method is provided for actively compensating for pressure changes of a working fluid within a conduit. A first cavity is provided in fluid communication with the conduit. A second cavity is in fluid communication with a control fluid. A plunger is in communication with both the first cavity and the second cavity and is movable in response to pressure changes of the working fluid in the conduit. The plunger is re-centered. Re-centering the plunger includes the following steps. Position data representative of movement of the plunger is collected. The position data is analyzed with a control unit to determine an average position of the plunger which is offset relative to a center position. The average position of the plunger is compared, with a control unit, to the center position. A signal is relayed from the control unit to a control valve to urge the plunger toward the center position.

An electronics for active cancellation of a pulsating flow with a source noise reference. The electronics includes a signal processor configured to receive a noise source signal and a flow signal. The signal processor is also configured to generate a cancelling signal based on the noise source signal and the flow signal. A controller is communicatively coupled to the signal processor, and configured to determine a flow rate control signal for controlling the flow rate of the pulsating flow. A signal generator coupled to the signal processor and the controller is configured to receive the flow rate control signal, generate a valve signal based on the flow rate control signal and the cancelling signal, and provide the valve signal to a valve to control the flow rate and attenuate the one or more pulses of the pulsating flow.

An engine exhaust flow meter and method of measuring engine exhaust flow rate includes a flow tube and a differential pressure meter that is adapted to measure differential pressure in exhaust flow through the flow tube. A computer samples the differential pressure meter at a rate that is greater than the pulsation of exhaust flow to obtain a differential pressure signal. The computer is responsive to the differential pressure signal to compute a mean differential pressure value. The computer is responsive to the differential pressure signal to compute a mean magnitude of pressure pulses. The computer determines a compensation factor as a function of the mean magnitude of pressure pulses and adjusts the mean differential pressure value as a function of the compensation factor to obtain an engine exhaust flow value that is flow pulsation compensated.

Liquid accumulators and methods for reducing pulsations of a liquid flow are disclosed. A liquid delivery system comprises a pump configured to drive liquid to a pipe. The pipe is configured to transmit a liquid flow. A liquid accumulator is fluidically connected to the pipe. The liquid accumulator comprises a chamber containing the liquid and a vapor column and a power source configured to input energy to the chamber to generate vapor from the liquid to form the vapor column. The vapor column constitutes a gas spring to reduce pulsations of the liquid flow in the pipe. The spring rate of the gas spring can be adjusted by changing the input energy level from the power source to the chamber.

Shock absorber used for damping a control flow which is to be directed to the control valve belonging to a hydraulic system or is to be directed to the adjustable valve of the flow through which absorber the flow of the hydraulic fluid can be directed at least in one direction. The absorber is a stopper which restricts the run of the flow to be damped which stopper is equipped with one or several ducts which let the flow go through the mentioned stopper when the other orifice of the mentioned duct is blocked with a plate in such a way that bending of the mentioned plate opens access for the flow through the mentioned stopper due to the pressure of the flow coming along the mentioned duct.

An air supply duct for fan is used to guide air to an air intake port of a fan, and includes a duct main body portion in which an air passage extending in a predetermined x direction with one end side set as an air inlet port is formed inside, and an air supply port for supplying air travelling through the air passage to the air intake port of the fan is arranged. A peripheral region of the air supply port of the inside of the duct main body portion is surrounded by wall portions in the periphery except for a communication portion with the air passage, and is configured as a space portion for generating air column vibration and having a width in a y direction intersecting the x direction larger than a width of the air passage. A combustion device including the air supply duct is provided.

Apparatus and a method for sampling fluid flow quality. The apparatus includes a flow channel through which the fluid is flowing, a pressure sensor provided in said flow channel and adapted to detect a pressure in said flow channel, a membrane provided downstream or upstream said pressure sensor in said flow channel and adapted to induce a pressure modification, and a control unit connected to said pressure sensor and said membrane. The control unit is configured to activate said membrane so as to induce said pressure modification when said detected pressure deviates from a predetermined pressure interval, thereby neutralizing any pressure fluctuation in said flow channel.

An electronics for active cancellation of a pulsating flow with a source noise reference. The electronics includes a signal processor configured to receive a noise source signal and a flow signal The signal processor is also configured to generate a cancelling signal based on the noise source signal and the flow signal. A controller is communicatively coupled to the signal processor and configured to determine a flow rate control signal for controlling the flow rate of the pulsating flow A signal generator coupled to the signal processor and the controller is configured to receive the flow rate control signal, generate a valve signal based on the flow rate control signal and the cancelling signal, and provide the valve signal to a valve to control the flow rate and attenuate the one or more pulses of the pulsating flow.

The present invention relates to a water piping system. More particularly, it relates to a water piping system that can alleviate water hammer due to slamming of a check valve by reducing the pressure difference between the front end and the rear end of the check valve by supplying some of fluid at the rear side of the check valve to the front side of the check valve when a pump is stopped, and a method of controlling the water piping system. The present invention includes: a sub-pipe having both ends connected to a front side and a rear side of the check valve, respectively, and supplying some of fluid at the rear side of the check valve to the front side of the check valve to suppress negative pressure and low pressure that is generated at the front end of the check valve when the pump is stopped.

A water hammer prevention system using an operation state analysis algorithm to prevents water hammer. Data is measured in real time by a pressure sensor and a water level sensor are transmitted to a control unit and stored in a database. The control unit includes an air chamber which controls the operations of an air compressor and an air exhauster to prevent water hammer. The control unit performs calculations according to a water hammer algorithm, and determines the operation states of the air compressor and the air exhauster, and whether the water hammer prevention equipment is operating normally. Active operational control of the water hammer prevention equipment can be performed by applying a data analysis technique thereto, and a failure or operation error can be identified.